EP1197597A1

EP1197597A1 - Hardened body, and method and device for manufacturing the hardened body

Info

Publication number: EP1197597A1
Application number: EP01915673A
Authority: EP
Inventors: Yoshiya Matsuno; Kenji Sato; Satoshi Ogawa; Toshihiro Nomura
Original assignee: Ibiden Co Ltd
Current assignee: Ibiden Co Ltd
Priority date: 2000-03-21
Filing date: 2001-03-21
Publication date: 2002-04-17
Also published as: WO2001071094A1

Abstract

A machine for producing a hardened product has an ingredient preparing mechanism 10 for preparing papermaking sludge and generating a slurry 14, a papermaking mechanism 20 having a carrying belt 23 for transferring and carrying a papermaking product produced from the slurry 14 in a papermaking manner by wire cylinders 22A, 22B and 22C, a reversing device 40, a pressing device 50 for pressing and dehydrating the papermaking product, and a dryer 60. A suction box 24 is set on the back face of the carrying belt 23 made of a felt, and suction is performed by a vacuum pump 17 to dehydrate the papermaking product. Therefore, water content in the papermaking product can be effectively reduced.

Description

Technical Field

This invention relates to a hardened product, and a hardened product producing process and a hardened product producing machine for mass-producing a hardened product having a high brightness and comprising papermaking sludge hardened into a plate form.

Background Art

In recent years, effective use of various industrial wastes has been investigated from the viewpoint of protection of global environment. For example, in the building industry, wherein forest resources have been consumed in large quantities up to now, it is suggested that the consumption of the forest resources is suppressed by newly consuming industrial wastes as construction materials. On the other hand, concerning inorganic boards that have been conventionally used, for example, calcium silicate boards, perlite boards, slug plaster boards, wood chip cement plates, and plaster boards, it has been demanded that costs thereof are reduced and functions thereof are made high.
The present inventors suggest, as Japanese Patent Application No. 10-352586, a technique wherein papermaking sludge, which is generated after making paper, is subjected to dehydrating press and is then dried and hardened to produce a hardened product which can be effectively used as a building panel or the like.
In the above-mentioned patent, the present inventor discloses that a hardened product can be obtained by hardening papermaking sludge. However, the disclosed process is not a process making it possible to produce the hardened product profitably. In order to mass-produce a hardened product in a practical manner, it has become necessary to establish a technique wherein water content is first gradually reduced from a resultant papermaking product containing a large volume of water content.
Papermaking sludge is colored by an effect of ink and pulp impurities, and the dehydrating press process has a problem that the impurities remain as they are in the hardened product. It drops the brightness of the hardened product so that the product cannot be colored or decorated.
The present invention has been made to solve the above-mentioned problem, and a first object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to effectively mass-produce a hardened product from papermaking sludge.
The first object is also to provide a hardened product having a high brightness.
The dehydrating process is poor in mass-productivity. In order to solve such problem, JP-A-49-114628 discloses a technique of preparing, in a rotary drum, a mixture of cement and papermaking sludge diluted until the solid content therein becomes 3%, transferring the mixture from the surface of this drum onto a belt-form blanket, subjecting the transferred mixture to dehydrating press, increasing the layer thickness thereof by means of a winding roll, cutting the blanket and then carrying the cut product on a conveyor.
JP-A-59-156956 discloses a papermaking process using a round wire gauze, and discloses techniques wherein mats are prepared in a papermaking manner one by one and the mats are formed into a multilayer. However, it has been found out that such a papermaking process results in a scattering in strength.
Furthermore, in WO 00/79052, papermaking sludge diluted so as to have a solid content of 3% in accordance with a known technique is used to make paper. The same problems as in the prior art arise.
The present invention has been made to solve the above-mentioned problem, and a second object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to mass-produce a hardened product effectively from papermaking sludge and make a scattering in the strength thereof small.
In the above-mentioned Japanese Patent Application No. 10-352586, the present inventor discloses that hardened products can be obtained by hardening papermaking sludge, but the resultant hardened products have a large scattering in density. In order to produce a hardened product which can be used for industrial applications, it has become necessary to establish a technique for producing dense and homogeneous hardened products.
JP-A-49-114628 discloses that it is preferred that organic components have a size of 200 meshes or less. In this technique, however, a problem arises that the brightness of a formed product prepared in a papermaking manner is low. JP-A-59-156956 discloses a papermaking process using a round wire gauze. In this process, mats are prepared one by one in a papermaking manner and the mats are formed into a multilayer. The round wire gauze used has meshes of No. 250 to 10. The process also has a problem that the brightness thereof is low.
In order to solve the above-mentioned problem, the present invention has been made, and a third object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to effectively mass-produce a hardened product having a high density from papermaking sludge.
In the JP-A-49-114628, the resultant products were inhomogeneous and problems such as exfoliation and warps were caused. JP-A-59-156956 discloses a papermaking process using a round wire gauze, wherein mats are prepared one by one in a papermaking manner and the mats are formed into a multilayer. Thus, this process is inefficient.
The present invention has been made to solve the above-mentioned problems, and a fourth object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to mass-produce effectively a hardened product which is homogeneous in the thickness direction thereof and in the surface thereof from papermaking sludge.
In the JP-A-49-114628, the cutting by means of the winding roll is required, and a cutting means such as a cutter is necessary. Thus, productivity is bad and a problem considering safety is also caused.
The present invention has been made to solve the above-mentioned problems, and a fifth object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to effectively mass-produce a hardened product and safely from papermaking sludge.
In the case that papermaking products are wound as in JP-A-49-114628 and JP-A-59-156956, stress remains therein. Thus, if the papermaking products are formed into a lamination and subsequently the lamination is dried, a problem that a warp or a delamination is generated in the hardened product arises.
The present invention has been made to solve the above-mentioned problems, and a sixth object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to produce a hardened product wherein no warp is generated from papermaking sludge.
In the Japanese Patent Application No. 10-352586, the invention discloses that hardened products can be obtained by hardening papermaking sludge. However, the resultant hardened product have a scattering in specific gravity and strength. In order to produce a hardened product which can be used for industrial applications, it is necessary to establish a technique for producing hardened products having a uniform specific gravity.
The present invention has been made to solve the above-mentioned problems, and a seventh object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to mass-produce hardened products having a uniform specific gravity from papermaking sludge.
In the JP-A-49-114628, there arises such a problem that the formed product prepared in a papermaking manner cleaves on the way of transportation thereof.
JP-A-59-156956 discloses a papermaking process using a round wire gauze, wherein mats are prepared one by one in a papermaking manner and the mats are formed into a multilayer. However, the problem that the mats cleave when the mats are raised for lamination arised.
That is, from further development of investigations for mass-producing hardened products in a practical manner, it has been made evident that the handling of a papermaking product prepared from papermaking sludge after the product is fashioned into a given shape is the difficulty. In other words, after a papermaking product made from papermaking sludge is fashioned into a given shape to produce a hardened product, the papermaking product contains a large volume of water content and therefore the handling of the product without damaging its shape is difficult.
The present invention has been made to solve the above-mentioned problems, and an eighth object thereof is to provide a hardened product producing process and a hardened product producing machine making the handling of a papermaking product easy and making it possible to mass-produce a hardened product from papermaking sludge.
In the Japanese Patent Application 10-352586, the present inventor discloses that a hardened product can be obtained by hardening papermaking sludge. However, it is impossible to obtain the strength that is appropriate for practical use for wide industrial applications. As a method to increase the strength, the present inventor had an idea to press a papermaking product produced from papermaking sludge, and made experiments. As a result, the present inventor was able to increase the strength of the hardened product by increasing the pressure applied. However, it has been proved that as the pressure is made higher, the papermaking product cleaves more easily so that the yield thereof becomes lower.
The present invention has been made to solve the above-mentioned problems, and a ninth object thereof is to provide a hardened product producing process and a hardened product producing machine making it possible to produce a high-strength hardened product from papermaking sludge.

Disclosure of the Invention

In order to achieve the first object, according to claim 1 to claim 4, a papermaking sludge hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge and comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca,
is characterized in that the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and
the brightness of the hardened product is N5 or more as the value based on the regulation of JIS Z 8721.
In order to achieve the seventh object, according to claim 5, a papermaking sludge hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge and comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca,
wherein the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and a flocculating agent is contained. Such a structure makes it possible to overcome a scattering in specific gravity, strength and also remove warps.
It is desired that the ingredient solution contains no cement or the solid content therein contains 30% or less by weight of cement. This is because papermaking property is improved by the incorporation of the cement but the strength drops and the brightness drops. The upper limit thereof is 30% by weight.
The hardened product of the present invention is a hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge. It comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca, wherein the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively. The brightness of the this hardened product is N5 or more as the value based on the regulation of JIS Z 8721. These Ca, Al and Si amounts (CaO, Al₂O₃ and SiO₂ converted amounts) are all amounts of Ca, Al and Si in the composite hardened product. For example, in the case of Ca, the amount thereof is the amount of all Ca in calcium carbonate and the inorganic amorphous material. Optimal is a hardened product wherein the ratio of CaO/SiO₂ is over 0.2 and 7.9 or less, and the ratio of CaO/Al₂O₃ is over 0.2 and 12.5 or less.
In order to achieve the eighth object, according to claim 6, a papermaking sludge hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge and comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca,
wherein the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and synthetic fibers are contained. Such a structure makes it possible to improve the bending strength and fracture toughness.
It is desired that the ingredient solution contains no cement or the solid content therein contains 30% or less by weight of cement. This is because papermaking property is improved by the incorporation of the cement but the strength drops and the brightness drops. The upper limit thereof is 30% by weight.
In order to achieve the first object stated above, a process for producing a hardened product according to claim 7 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
For this reason, the hardened product can be mass-produced from papermaking sludge.
In order to achieve the second object stated above, a process for producing a hardened product according to claim 8 is characterized by using a rotary drum rotating at 1 to 100 times/minute to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the rotary drum, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. For this reason, the hardened product can be mass-produced from papermaking sludge.
If the rotation speed of the rotary drum is below 1 time/minute, the fibers are oriented in the thickness direction of the papermaking product to result in a scattering in strength. If the speed is over 100 rotation/minute, the fibers are oriented in the rotation direction so that the strength is scattered.
In order to achieve the third object stated above, a process for producing a hardened product according to claim 9 is characterized by using a drainage body having a mesh structure of #40 to 150 to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the papermaking product can be produced with high efficiency from the ingredient solution, and a hardened product having a high density can be mass-produced from papermaking sludge. If the mesh is rougher than #40, only the inorganic amorphous material falls out from the ingredient solution causing a drop in the density and the strength of the hardened product. On the other hand, if the mesh is finer than #150, the falling-out of the water content becomes poor so that the papermaking product cannot be produced with a high efficiency from the ingredient solution. The density drops by voids because of the remaining water content.
In order to achieve the fourth object stated above, a process for producing a hardened product according to claim 10 is characterized by using a rotary drum composed of a netlike body to subject an ingredient solution containing papermaking sludge and having a solid content concentration of 3.5 to 25% by weight to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the netlike rotary drum, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the property of the papermaking from papermaking sludge is improved so that the hardened product can be efficiently mass-produced. That is, if the concentration is below 3.5%, the solution is too weak, and takes long time to keep the thickness. Moreover, as time passes, the concentration drops so that the uniformity of the thickness direction drops. If the concentration is over 25%, the in-plane uniformity of the product falls. For this reason, warps are generated by drying.
In order to achieve the first object stated above, a process for producing a hardened product according to claim 11 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt having a speed of 5 to 80 m/minute, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. Since the carrying speed of the carrying belt is from 5 to 80 m/minute, the papermaking product having an appropriate thickness can be produced with high efficiency from the ingredient solution so that the hardened product can be efficiently mass-produced from the papermaking sludge. If the carrying speed of the carrying belt is slower than 5 m/minute, the papermaking product can be produced to have a large thickness but papermaking efficiency is low and unevenness in the thickness is generated. On the other hand, if the carrying speed is over 80 m/minute, the papermaking becomes thin. Thus, it is difficult to make uniform thickness and the papermaking product may cleave. The thickness also has unevenness.
In order to achieve the first object stated above, a process for producing a hardened product according to claim 12 is characterized by using a rotary drum composed of a netlike body to subject, to a papermaking manner, an ingredient solution containing papermaking sludge in which the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and adhering a papermaking product of the papermaking sludge to a surface of the rotary drum, and further transferring this papermaking product onto a carrying belt of a porous body having continuous pores, dehydrating the papermaking product while carrying the papermaking product on the carrying belt, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. Since the papermaking product is dehydrated while being carried on the carrying belt, the water content in the papermaking product can be efficiently reduced. Thus, the hardened product can be mass-produced. Particularly since the rotary drum in the netlike form is used to produce the hardened product in the papermaking manner and impurities drop out from its meshes, the impurities can be reduced, and the brightness can be made high. Particularly since the impurities, ink and so on can be removed during the dehydration while the papermaking product is carried on the carrying belt, the present embodiment is optimal for making the brightness high. The embodiment is a hardened product comprising calcium carbonate, wherein the amounts of Ca, Al and Si, the amounts being conversed into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively. Therefore, the amount of the Ca component becomes large so that the brightness is improved. Also because the strength and the nailing performance are high. Therefore, the brightness of the hardened product can be made to N5 or more as the value based on the regulation of JIS Z 8721.
The brightness N is defined as follows: the brightness of ideal black is made to 0; that of ideal white is made to 10; respective colors are divided into 10 parts in the manner that the brightness thereof is recognized stepwise between the brightness of black and that of white; and the resultant parts are indicated by symbols N0-N10.
Actual brightness is measured by comparison with color charts corresponding to N0-N10. One place of decimals in this case is made to 0 or 5. Since the brightness of the hardened product can be set to N5 or more as the value based on the regulation of JIS Z 8721, the hardened product can be colored or decorated.
The crystal habit of the calcium carbonate is desirably in at least one form selected from spindle, horn, thin table, cubic and columnar forms. This is because the calcium carbonate can be taken in the hardened product even in papermaking since it has a high whiteness and it gets entangled in the fibers because of its corners so that it does not fall out easily.
In the case that the papermaking sludge cement is added, the content thereof is desirably 30% or less by weight. This is because the brightness drops if the content of the papermaking sludge cement increases. This is also because it can be recognized that by adding the cement, the strength also drops.
JP-A-55-12853 discloses a technique of dehydrating papermaking sludge by wire press and then hot-pressing the sludge. However, according to "Report on Papermaking Industrial Examination Laboratory in Sizuoka Prefecture" published in 1979, the sludge at that time had only 2.6% of Ca by weight in terms of CaO. Thus, the strength is insufficient. Since the product is not produced by papermaking, the product contains a large volume of impurities. As a result, its brightness is low.
JP-B-57-19019 discloses a product obtained by press-molding a mixture of papermaking sludge and montmorillonite. However, as papermaking sludge at that time, Ca components are little in amount and it is not made of Ca based crystal. Thus, the compressive strength thereof is poor. JP-A-50-101604 discloses a board obtained by mixing papermaking sludge and hydrophobic fibers and adding a binder thereto. However, as papermaking sludge at that time, Ca components are little in amount, and the bending strength thereof is 2.5 kg/cm². Even products being combined and having a high strength have a strength of only about 15 kg/cm². Thus, the present invention is far better. JP-A-52-90585 discloses a product wherein the surface of papermaking sludge is treated with paraffin. However, as papermaking sludge at that time, Ca components are small in amount so that the strength would be poor. Anyhow, since the product is not produced by papermaking in all cases, the product contains a great quantity of impurities. As a result, its brightness is low.
Since the rotary drum in a netlike form is used to produce a hardened product in a papermaking manner and impurities drop out from its meshes, the impurities can be reduced and its brightness can be made high.
JP-A-49-114628 discloses a technique of preparing, in a rotary drum, a mixture of cement and 3%-diluted papermaking sludge, transferring the mixture from the surface of this drum onto a belt-form blanket, subjecting the transferred mixture to dehydrating press, increasing the layer thickness thereof by means of a winding roll, cutting the blanket and then carrying the cut product on a conveyor.
In this technique, however, the ratio of CaO is small and the brightness is lowered. Cement is contained 55% or more in percentage, and this causes the brightness to be lowered. JP-A-59-156956 discloses a papermaking process using a round wire gauze, wherein mats are prepared one by one in a papermaking manner and the mats are formed into a multilayer. However, this process is not efficient.
In order to achieve the fifth object stated above, a process for producing a hardened product according to claim 13 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product onto a cutting rotary drum, cutting the papermaking product into a given size when the multilayered papermaking product turns into a given thickness, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. Since the papermaking product having uniform thickness and size can be continuously formed by means of the cutting rotary drum, the hardened product can be effectively mass-produced.
Since the papermaking product is formed into the multilayer by the cutting rotary drum having a cutting mechanism, the process can be made automatic without the necessity of cutting. The cutting mechanism is preferably a mechanism having a blade 35 contacting a cutting rotary drum 30 substantially perpendicularly as in FIG.20, or a mechanism having a groove 31 in which water can be accumulated and a mechanism 32 for pushing out a papermaking product 26 from the inside as in FIG.21. In FIG. 20, a papermaking product having a constant length can be mass-produced by pushing the blade 35 against the cutting rotary drum 30 in synchronization with the drum 30.
On the other hand, in the mechanism of FIG. 21 water remaining on the surface of the groove 32 penetrates into the papermaking product 26 so that it locally becomes soft, and then cutting can be attained by pushing out the papermaking product from the inside by means of a piano wire 31. This can ensure operator's safety since no sharp blade is used.
In order to achieve the first object stated above, a process for producing a hardened product according to claim 14 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner, laminating resultant papermaking products of the papermaking sludge, and pressing the laminated papermaking products at a pressure of 10 to 250 kg/cm². It is ineffective to obtain a thick papermaking product in a papermaking manner; therefore, the hardened product having required strength and thickness can be produced by preparing papermaking products having a small thickness effectively from the papermaking sludge and making the products into a lamination. Therefore, the hardened product can be effectively mass-produced from the papermaking sludge. Since the papermaking product is pressed after the formation of the lamination, the hardened product having required thickness can easily be produced. Press is performed at 10 to 250 kg/cm². If the press is performed at less than 10 kg/cm², required strength cannot be obtained. On the other hand, even if the press is performed at more than 250 kg/cm², the strength cannot be made high so that the press machine becomes large-sized and expensive. Furthermore, at less than 10 kg/cm² voids are generated so that the strength is lowered and an exfoliation or a warp is caused. Contrarily, at more than 250 kg/cm², the fibers are oriented in the direction along which the pressure is applied, so that the strength is lowered and an exfoliation or a warp is caused. In a papermaking manner, fibers are originally easily oriented. Thus, high pressure is inconvenient.
In order to achieve the sixth object stated above, a process for producing a hardened product by laminating papermaking products of papermaking sludge obtained by subjecting an ingredient solution containing the papermaking sludge to a papermaking manner, and then hardening the papermaking products, according to claim 15, is characterized in that the papermaking products are alternately made reverse and laminated when the papermaking products are laminated. That is, no warp or delamination is generated in the hardened product comprising the laminated papermaking products since the papermaking products are formed into the lamination while the direction in which a warp is generated is made reverse.
In order to achieve the sixth object, a process for producing a hardened product according to claim 16 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product onto a cutting rotary drum, cutting the papermaking product into a given size, and laminating and hardening resultant papermaking products,
characterized in that the papermaking products are alternately made reverse and laminated when the papermaking products are laminated. That is, no warp or delamination is generated in the hardened product comprising the laminated papermaking products since the papermaking products are formed into the lamination while the direction in which a warp is generated is made reverse.
In order to achieve the sixth object, a process for producing a hardened product according to claim 17 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product onto a cutting rotary drum, cutting the papermaking product into a given size, and laminating and hardening the resultant papermaking products to obtain the hardened product of the papermaking sludge,
characterized in that when the papermaking products are laminated, naked faces of the papermaking products of the topmost layer and the lowermost layer are made to faces contacting the rotary drum, and laminating faces of the papermaking products are laminated while they are alternately made reverse. That is, no warp or delamination is generated in the hardened product comprising the laminated papermaking products since the papermaking products are formed into the lamination while the direction in which a warp is generated is made reverse. Concerning the papermaking products of the topmost layer and the undermost layer, their naked surfaces are made to faces contacting the rotary drum. Therefore, the surface of the hardened product comprising the lamination can be made smooth.
In order to achieve the sixth object, a process for producing a hardened product according to claim 18 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, cutting the papermaking product into a given size, and laminating and hardening the resultant papermaking products,
characterized in that when the papermaking products are laminated, the papermaking products are laminated in the manner that the transferring direction thereof to the carrying belt is shifted. In the papermaking products, a strength difference is generated along the transferring direction to the carrying belt. However, when the papermaking products are formed into the lamination, the hardened product having a uniform strength can be produced by laminating in order to cause the transferring direction to the carrying belt to be off to the side, that is, be shifted.
In order to achieve the seventh object stated above, a process for producing a hardened product according to claim 19 is characterized by adding a flocculating agent to an ingredient solution containing papermaking sludge to flocculate the solution, using a drainage body to subject this flocculated ingredient solution to a papermaking manner, and hardening this papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the hardened product having a uniform specific gravity can be mass-produced from papermaking sludge. Since flocks are formed in the papermaking sludge by the flocculating agent, papermaking efficiency can be improved.
In order to achieve the seventh object, a process for producing a hardened product according to claim 20 is characterized by adding a flocculating agent to an ingredient solution containing papermaking sludge to flocculate the solution, using a drainage body to subject this flocculated ingredient solution to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product to a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the hardened product having a uniform specific gravity can be mass-produced from the papermaking sludge. Since flocks are formed in the papermaking sludge by the flocculating agent, papermaking efficiency can be improved.
In order to achieve the eighth object stated above, a process for producing a hardened product according to claim 21 is characterized by adding a binder to an ingredient solution containing papermaking sludge, using a drainage body to subject this ingredient solution to a papermaking manner, and hardening this papermaking product to obtain the hardened product of the papermaking sludge. Since the binder causes the papermaking product to have flexibility, the handling thereof after cutting becomes easy so that the hardened product can be mass-produced. Moreover, the binder makes the strength and the toughness of the hardened product high.
In order to achieve the eighth object, a process for producing a hardened product according to claim 22 is characterized by adding a binder to an ingredient solution containing papermaking sludge, using a drainage body to subject this ingredient solution to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product to a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge. Since the binder causes the papermaking product to have flexibility, the handling thereof becomes easy so that the hardened product can be mass-produced. Moreover, the binder makes the strength and the toughness of the hardened product high.
In order to achieve the ninth object stated above, a process for producing a hardened product according to claim 23 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner, and pressing a resultant papermaking product of the papermaking sludge in a mold frame to obtain the hardened product of the papermaking sludge. Since the process is performed in the mold frame, the papermaking product does not cleave even if it is pressed at a high pressure. The hardened product having a high strength can be produced with a high yield from the papermaking sludge.
In order to achieve the ninth object, a process for producing a hardened product according to claim 24 is characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner, laminating resultant papermaking products of the papermaking sludge, and pressing the laminated papermaking products to produce the hardened product of the papermaking sludge. Since the process is performed in the mold frame, the papermaking product does not cleave even if it is pressed at a high pressure. The hardened product having a high strength can be produced with a high yield from the papermaking sludge. Additionally, the hardened product having a required thickness can easily be produced since the papermaking products are formed into the lamination and subsequently the lamination is pressed.
In the process for producing the hardened product according to claim 25, the concentration of the solid content of the ingredient solution comprising the papermaking sludge is from 3.5 to 25% by weight; therefore, the property of papermaking from the papermaking sludge is improved so that the hardened product can be effectively mass-produced. That is, at a concentration of less than 3.5%, no effective papermaking from the ingredient solution can be performed using the drainage body. At more than 25%, the uniformity of products drops.
In the process for producing the hardened product according to claim 26, the papermaking product is dehydrated while it is carried on the carrying belt; therefore, water content in the papermaking product can be effectively reduced.
In the process for producing the hardened product according to claim 27, the papermaking product on the carrying belt is formed into the lamination while it is transferred onto the cutting rotary drum, and the papermaking product formed into the lamination is cut when it reaches a given thickness; therefore, the papermaking product having a uniform thickness can be continuously formed.
In the process for producing the hardened product according to claim 28, the cut papermaking product is further formed into the lamination and subsequently it is pressed; therefore, the hardened product having a required thickness can easily be produced.
In the process for producing the hardened product according to claim 29, the press is performed at 10 to 250 kg/cm². If the press is performed at less than 10 kg/cm², no required strength can be obtained. On the other hand, even if the press is performed at more than 250 kg/cm², the strength cannot be made high and the press machine becomes large-sized and expensive.
In the process for producing the hardened product according to claim 30, the ingredient solution contains no cement, or solid content in the solution comprises 30% or less by weight of cement. By the incorporation of the cement, papermaking property is improved but the strength is lowered and the brightness is also lowered. The upper limit is 30% by weight.
In the process for producing the hardened product according to claim 31, the papermaking product is formed into the lamination between the respective layers of which the ingredient solution is interposed; therefore, the hardened product having a multilayer structure and causing no exfoliation can be produced.
In the process for producing the hardened product according to claim 32, the papermaking sludge is effectively subjected to the papermaking manner by making the papermaking product to have a thickness of 20 mm or less, and the hardened product having required strength and thickness is produced by the laminating. For this reason, the hardened product can be effectively mass-produced from the papermaking sludge.
In the process for producing the hardened product according to claim 33, the flocculating agent is any one of aluminum sulfate, ferric chloride, polyaluminum chloride, polysodium acrylate, ester of polymethacrylic acid, ester of polyacrylic acid, and polyacrylamide; therefore, the ingredient solution comprising the papermaking sludge can be effectively flocculated.
In the process for producing the hardened product according to claim 34, the binder is the organic fiber. This causes the papermaking product to have flexibility.
In order to achieve the first object, a machine for producing a hardened product according to claim 35 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the hardened product can be effectively mass-produced from the papermaking sludge.
In order to achieve the second object, a machine for producing a hardened product according to claim 36 is characterized by comprising: a rotary drum for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drum, the rotation speed thereof being from 1 to 100 times/minute, a carrying belt for transferring the papermaking product adhered to the surface of the rotary drum and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the hardened product can be effectively mass-produced from the papermaking sludge.
In order to achieve the third object, a machine for producing a hardened product according to claim 37 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, the drainage body having a mesh structure of #40 to 150, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the papermaking product can be effectively produced in the papermaking manner from the ingredient solution, and the hardened product having a high density can be effectively mass-produced from the papermaking sludge. If the meshes are rougher than #40, only an inorganic non-crystal product falls out from the ingredient solution so that the density and the strength of the hardened product drop. On the other hand, if the meshes are finer than #150, the falling-out of water content deteriorates so that the papermaking product cannot be produced in the papermaking manner from the ingredient solution. Moreover, the water content remains, and voids are generated by drying. As a result, the density is lowered.
In the case of less than #40 (that is, rough meshes), it is impossible to take in calcium carbonate, which gives the whiteness. In the case of more than #150 (that is, fine meshes), impurities are taken in. In either case, the brightness is lowered.
In order to achieve the fourth object, a machine for producing a hardened product according to claim 38 is characterized by comprising: a rotary drum, which is composed of a netlike body, for subjecting an ingredient solution containing papermaking sludge and having a solid content concentration of 3.5 to 25% by weight to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drum, a carrying belt for transferring the papermaking product adhered to the surface of the netlike rotary drum and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the property of papermaking from the papermaking sludge is improved so that the hardened product can be effectively mass-produced. That is, if the concentration is below 3.5%, the concentration is low so that effective papermaking from the ingredient solution cannot be performed using the rotary drum. Moreover, the concentration becomes lower as time passes. Thus, the hardened product becomes ununiform in the thickness direction. If the concentration is over 25%, the in-plane uniformity of the finished product is lowered. If the product becomes ununiform, an exfoliation or a warp is generated from drying.
In order to achieve the first object, a machine for producing a hardened product according to claim 39 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, the carrying speed thereof being from 5 to 80 m/minute, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge. Since the carrying speed of the carrying belt is from 5 to 80 m/minute, the papermaking product having an appropriate thickness can be produced from the ingredient solution in the papermaking manner, so that the hardened product can be effectively mass-produced from the papermaking sludge. If the carrying speed is slower than 5 m/minute, the papermaking product can be made thick but papermaking efficiency is low and the uniformity of the thickness is low. On the other hand, if the carrying speed is over 80 m/minute, the papermaking product becomes thin. Thus, it is difficult to make uniform thickness, and the papermaking product may cleave.
In order to achieve the first object, a machine for producing a hardened product according to claim 40 is characterized by comprising: a rotary drum, which is composed of a netlike body, for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drum, a porous carrying belt for transferring the papermaking product adhered to the surface of the rotary drum, and dehydrating the papermaking product while carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge. Since the papermaking product is dehydrated while it is carried on the carrying belt; therefore, water content in the papermaking product can be effectively reduced. Thus, the hardened product can be mass-produced. Since the rotary drum composed of the netlike body is used, the papermaking product can be continuously produced from the ingredient solution in the papermaking manner and the hardened product can be effectively mass-produced from the papermaking sludge. The rotary drum of the netlike body is used to produce the hardened product in the papermaking manner so that impurities fall out from its meshes; therefore, the impurities can be decreased and the brightness can be made high.
In order to achieve the fifth object, a machine for producing a hardened product according to claim 41 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, a cutting rotary drum for forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product, the cutting rotary drum comprising a groove wherein water is accommodated in its surface and a pushing-out mechanism, positioned near this groove, for pushing out the papermaking product from its inside, wherein the pushing-out mechanism is operated when the papermaking product whose surface is multilayered turns into a given thickness, thereby cutting the papermaking product at a position corresponding to the groove, and a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge. Therefore, the papermaking product having a uniform thickness can be continuously formed so that the hardened product can be effectively mass-produced. Safety is high since blades such as a cutter is not used.
This will be described, referring to FIG. 21. FIGs. 21(A) and (B) are explanatory views of cutting rotary drums. FIG. 21(C) is a perspective view of a cutting rotary drum. As illustrated in FIG. 21(A), a groove 32 in which surface water remains is made in a cutting rotary drum 30, and this water makes soft regions (W) locally in a papermaking product 26 of papermaking sludge. As illustrated in FIGs. 21(B) and (C), a piano wire 31 is next pushed out so that the papermaking product 26 of the papermaking sludge is pushed out from the inside. As a result, the papermaking product fractures at the locally-softened region W, so that cleavage is caused.
In order to achieve the first object, a machine for producing a hardened product according to claim 42 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a laminating device for laminating the cut papermaking products of the papermaking sludge so that the ingredient solution is interposed therebetween. Since it is ineffective that a thick papermaking product is obtained in the papermaking manner, thin papermaking products can be effectively produced from the papermaking sludge in the papermaking manner and then the papermaking products are formed into the lamination.
In this way, the hardened product having required strength and thickness is produced. Therefore, the hardened product can be mass-produced from the papermaking sludge. In addition, the papermaking product is formed into the lamination between the respective layers of which the ingredient solution interposed; therefore, the hardened product having a multilayer structure which does not cause exfoliation can be produced.
In order to achieve the sixth object, a machine for producing a hardened product according to claim 43 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a laminating device for making the cut papermaking products of the papermaking sludge reverse alternately and laminating the papermaking products. That is, the papermaking products are laminated while the direction along which a warp is generated is made reverse; therefore, no warp or delamination is generated in the hardened product comprising the laminated papermaking products.
In order to achieve the ninth object, a machine for producing a hardened product according to claim 44 is characterized by comprising: a papermaking device for subjecting an ingredient solution containing papermaking sludge to a papermaking manner to produce a papermaking product of the papermaking sludge, and a pressing device for putting the papermaking product of the papermaking sludge into a mold frame and then pressing the papermaking product, the pressing device comprising a hole for releasing water content exuding from the papermaking product. Since the process is performed in the mold frame, the papermaking product does not cleave even if it is pressed at a high pressure. Thus, the hardened product having a high strength can be produced with a high yield from the papermaking sludge. The mold frame has the hole for releasing water content exuding from the papermaking product; therefore, dehydration is performed at the time of pressing and subsequently a hardening step based on drying is completed in a short time.
In order to achieve the ninth object, a machine for producing a hardened product according to claim 45 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and a pressing device for putting the papermaking product of the papermaking sludge into a mold frame and then pressing the papermaking product, the pressing device comprising a hole for releasing water content exuding from the papermaking product. Since the process is performed in the mold frame, the papermaking product does not cleave even if it is pressed at a high pressure. Thus, the hardened product having a high strength can be produced with a high yield from the papermaking sludge. The mold frame has the hole for releasing water content exuding from the papermaking product; therefore, dehydration is performed at the time of pressing and subsequently a hardening step based on drying is completed in a short time. Moreover, the papermaking product is formed into a lamination and subsequently the lamination is pressed; therefore, the hardened product having a required thickness can easily be produced.
In order to achieve the ninth object, a machine for producing a hardened product according to claim 46 is characterized by comprising: a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, a cutting device for cutting the papermaking product carried on the carrying belt into a given size, a laminating device for laminating the cut papermaking products of the papermaking sludge so that the ingredient solution is interposed therebetween, and a pressing device for putting the papermaking product of the papermaking sludge into a mold frame and then pressing the papermaking product, the pressing device comprising a hole for releasing water content exuding from the papermaking product. Since the process is performed in the mold frame, the papermaking product does not cleave even if it is pressed at a high pressure. Thus, the hardened product having a high strength can be produced with a high yield from the papermaking sludge. The mold frame has the hole for releasing water content exuding from the papermaking product; therefore, dehydration is performed at the time of pressing and subsequently a hardening step based on drying is completed in a short time. Moreover, the papermaking products of the papermaking sludge are formed into the lamination between the respective layers of which the ingredient solution is interposed; therefore, the hardened product having a multilayer structure which does not cause delamination can be produced.
The machine for producing the hardened product according to claim 47 comprises the rotary drum whose drainage body is composed of the netlike body. Therefore, the papermaking product can be continuously produced from the ingredient solution in the papermaking manner, so that the hardened product can be effectively mass-produced from the papermaking sludge.
In the machine for producing the hardened product according to claim 48, the rotation speed of the rotary drum is from 1 to 100 times/minute; therefore, the papermaking product can be effectively produced from the ingredient solution in the papermaking manner, so that the hardened product can be effectively mass-produced from the papermaking sludge. If the rotary drum is lower than one rotation/minute, papermaking efficiency is low. On the other hand, if the rotation number is over 100 rotations/minute, it is difficult to produce the papermaking product having a uniform thickness.
In the machine for producing the hardened product according to claim 49, a plurality of the drainage bodies are arranged along the carrying belt and the papermaking product is transferred onto the carrying belt while the papermaking product is formed into a lamination. Therefore, the papermaking product can be effectively produced from the ingredient solution in the papermaking manner so that the hardened product can be mass-produced from the papermaking sludge.
In the machine for producing the hardened product according to claim 50, its drainage body has a mesh structure of #40-150. Therefore, the papermaking product can be effectively produced from the ingredient solution in the papermaking manner so that the hardened product having a high density can be effectively mass-produced from the papermaking sludge. If the meshes are rougher than #40, only the inorganic amorphous material falls out from the ingredient solution so that the density and the strength of the hardened product drop. On the other hand, if the mesh is finer than #150, the falling-out of water content becomes poor so that the papermaking product cannot be produced with a high efficiency from the ingredient solution.
In the machine for producing the hardened product according to claim 51, the carrying speed of the carrying belt is from 5 to 80 m/minute; therefore, the papermaking product having an appropriate thickness can be effectively produced from the ingredient solution in the papermaking manner so that the hardened product can be effectively mass-produced from the papermaking sludge. If the carrying speed is lower than 5 m/minute, the papermaking product can be made thick but papermaking efficiency is low. On the other hand, if the carrying speed is over 80 m/minute, the papermaking product becomes thin. Thus, the uniform thickness is not easily made and the papermaking product may cleave.
In the machine for producing the hardened product according to claim 52, the carrying belt is composed of the porous body having continuous pores; therefore, the papermaking product can be dehydrated while it is carried on the carrying belt. Thus, water content in the papermaking product can be effectively reduced.
In the machine for producing the hardened product according to claim 53, the cutting device comprises the cutting rotary drum for transferring the papermaking product while forming it into the lamination. At the stage in which the papermaking product formed into the lamination, on the surface of the cutting rotary drum, has the given thickness, the pushing-out mechanism is operated and the papermaking product is cut at the position corresponding to the groove. Therefore, the papermaking product having a uniform thickness can be effectively produced.
In the machine for producing the hardened product according to claim 54, the cutting device has the blade for cutting, at regular intervals, the papermaking product whose end is cut by means of the cutting rotary drum. Therefore, the papermaking product having a given length can be effectively formed.
In the machine for producing the hardened product according to claim 55, the cutting device has the blade for cutting, at regular intervals, the papermaking product whose end is cut by means of the cutting rotary drum. Therefore, the papermaking product having a given length can be effectively formed.
In the machine for producing the hardened product according to claim 56, the laminating device causes the papermaking products of the papermaking sludge to form into the lamination between the respective layers of which the ingredient solution is interposed. Therefore, the hardened product having a multilayer structure which does not cause exfoliation can be produced.

Brief Description of Drawings

FIG. 1 is a schematic sectional view of a composite hardened product of this invention.
FIG. 2 is a schematic sectional view of a composite hardened product of this invention.
FIG. 3 is a conceptual view of a machine for producing a hardened product according to a first embodiment of the present invention.
FIGs.4(A) and (B) are conceptual views of an ingredient-adjusting mechanism.
FIG. 5 is a conceptual view of a papermaking mechanism.
FIGs. 6(A), (B) and (C) are explanatory views of a cutting rotary drum.
FIGs. 7(A), (B), and (C) are explanatory views of the operation of a reversing device.
FIGs. 8(A), (B), and (C) are explanatory views of the operation of a press machine.
FIGs. 9(A), (B), and (C) are explanatory views of the operation of the press machine.
FIGs. 10(A), (B), and (C) are explanatory views of the direction along which papermaking products are adhered to each other.
FIG. 11 is a diagram showing a relationship between the adhering direction of the papermaking products and generation of delamination, and a relationship between the pressure and the strength of the press machine.
FIG. 12 is a chart of X-ray diffraction of the composite hardened product according to Example 1.
FIG. 13 is a chart of X-ray diffraction of the composite hardened product according to Example 1.
FIG. 14 is a conceptual view of a machine for producing a hardened product according to a second embodiment of the present invention.
FIG. 15 is a graph showing a relationship between CaO/SiO₂ and compressive strength.
FIG. 16 is a graph showing a relationship between CaO/Al₂O₃ and compressive strength.
FIG. 17 is a graph showing a relationship between the content of CaO and bending strength/compressive strength.
FIG. 18 is a graph showing a relationship the content of CaO and nail pulling-out strength.
FIG. 19 is a schematic sectional view of a composite construction material using a composite hardened product of this invention.
FIG. 20 is an explanatory view of a cutting rotary drum.
FIGs. 21 (A), (B) and (C) are explanatory views of the operation of the cutting rotary drum.

Best Mode for Carrying Out the Invention

The structure of a composite hardened product produced by the composite hardened product producing process of this invention, which will be described later, is first described on the basis of the schematic view of FIG. 1. Basically, this composite hardened product 1 comprises an inorganic amorphous material 2 made of a system of two or more oxides, and an organic fibrous material 3 is intermixed with the inorganic amorphous material 2. The inorganic amorphous material made of the system of the two or more oxides is an amorphous material of an oxide (1) an oxide (2).....an oxide (n) system wherein n is a natural number, and the oxide (1), the oxide (2), .....the oxide (n) are different oxides from each other.
It is difficult that such an amorphous material is precisely defined, but the amorphous material can be considered to be an amorphous compound produced by subjecting two or more oxides to solid-solution, hydration reaction or the like. In such an inorganic amorphous compound, elements constituting the oxides (two or more selected from Al, Si, Ca, Na, Mg, P, S, K, Ti, Mn, Fe and Zn) are identified by fluorescent X-ray analysis, and halo can be observed within the range of 2 = 10° to 40° in a chart of X-ray diffraction analysis. This halo is a gentle undulation of X-ray strength and is observed as a broad hill in the X-ray chart. The half width of the halo is as follows: 2 = 2° or more.
In the composite hardened product 1, the inorganic amorphous material 2 is first a strength-exhibiting material and further the organic fibrous material 3 is dispersed in the inorganic amorphous material 2 to improve the fracture toughness. Therefore, the bending strength value and the impact-resistance can be improved. Moreover, a homogeneous hardened product whose strength is isotropic can be obtained. Furthermore, an advantage that a low density and a sufficient strength can be obtained is produced because of the amorphous material.
The reason why the above-mentioned amorphous material is a strength-exhibiting material is not clear. However, it is presumed that the development of cracks is more blocked in the amorphous material than in crystal structure. Since a fibrous material is more uniformly dispersed in amorphous material than in crystal, it can be considered that the fracture toughness value is also improved. As a result, no crack is generated even if a nail is knocked thereinto and a through hole is made therein. Therefore, the amorphous material is optimal for materials which are required to be worked, such as construction materials.
The oxides which can be used are oxides of metals and/or nonmetals, and are desirably selected from Al₂O₃, SiO₂, CaO, Na₂O, MgO, P₂O₅, SO₃, K₂O, TiO₂, MnO, Fe₂O₃ and ZnO. Particularly, amorphous materials comprising an Al₂O₃-SiO₂-CaO system or Al₂O₃-SiO₂-CaO-oxide system, or a composite material of these amorphous materials are optimal. The oxides of the latter amorphous oxides are one or more oxides of metals and nonmetals other than Al₂O₃, SiO₂ and CaO.
The amorphous material comprising the Al₂O₃-SiO₂-CaO system is a compound which has an amorphous structure and is produced by solid-solution, hydration reaction or the like of all or a part of the components of Al₂O₃, SiO₂ and CaO. In other words, it can be considered that the amorphous material contains any one of compounds produced by subjecting a combination of Al₂O₃ and SiO₂, SiO₂ and CaO, Al₂O₃ and CaO, or Al₂O₃, SiO₂ and CaO to solid-solution, hydration reaction or the like.
In such an inorganic amorphous compound, Al, Si and Ca are identified by fluorescent X-ray analysis, and in a chart of X-ray diffraction analysis thereof the above-mentioned halo is observed within the range of 2 = 10° to 40°.
It is also considered that the system wherein at least one oxide is added besides Al₂O₃, SiO₂ and CaO, that is, the amorphous material comprising the Al₂O₃-SiO₂-CaO-oxide system contains not only any combination in the above-mentioned Al₂O₃-SiO₂-CaO system but also any one of compounds produced by subjecting a combination of Al₂O₃ and the oxide, SiO₂ and the oxide, CaO and the oxide, Al₂O₃, SiO₂ and the oxide, SiO₂, CaO and the oxide, Al₂O₃, CaO and the oxide, or Al₂O₃, SiO₂, CaO and the oxide to solid solution, hydration reaction or the like.
If the above-mentioned oxides are two or more amorphous materials, that is, amorphous materials of an Al₂O₃-SiO₂-CaO-oxide (n) system wherein n is a natural number of two or more, the amorphous materials are considered to contain any one of a compound produced by subjecting a combination of at least two selected from these oxides, for example, an oxide (1), an oxide (2).....an oxide (n) system (wherein n is a natural number of 2 or more; if n is difficult about the oxides (n), they are different oxides; and the oxides (n) are oxides other than Al₂O₃, SiO₂ and CaO) to solid-solution, hydration reaction or the like, a product produced by subjecting a combination of at least two selected from Al₂O₃, SiO₂ and CaO to solid-solution, hydration reaction or the like, and a product produced by subjecting a combination of at least one selected from an oxide (1), an oxide (2).....an oxide (n) system (wherein n is a natural number of 2 or more) with at least one selected from Al₂O₃, SiO₂ and CaO to solid-solution, hydration reaction or the like.
In such an inorganic amorphous compound, not only Al, Si and Ca but also elements constituting the oxides (two or more selected from Na, Mg, P, S, K, Ti, Mn, Fe and Zn) are identified by fluorescent X-ray analysis, and the above-mentioned halo can be observed within the range of 2 = 10° to 40°in a chart of X-ray diffraction analysis thereof.
The oxide(s) which is/are combined with Al₂O₃, SiO₂ and CaO is of one or more kinds. Oxides of metals and/or nonmetals except Al₂O₃, SiO₂ and CaO can be used. The oxide(s) can be selected from, for example, Na₂O, MgO, P₂O₅, SO₃, K₂O, TiO₂, MnO, Fe₂O₃ and ZnO. The selection can be performed on the basis of properties expected for the composite hardened product.
For example, Na₂O or K₂O can be removed with an alkali or the like. Therefore, if removing treatment is performed before plating treatment, the surface to be plated of the composite hardened product becomes rough so that the hardened product can be caused to act as an anchor for plating.
MgO is subjected to solid-solution in Al₂O₃, SiO₂ and CaO, so as to contribute to strength exhibition and improve the bending strength and the impact-resistance highly.
P₂O₅ is particularly advantageous in the case that the hardened product is used as a living body material (an artificial tooth or an artificial bone) for helping adhesion to bones.
SO₃ has a sterilizing effect and is suitable for antibacterial construction materials.
TiO₂ is a white coloring material, and also functions as a photooxidizing catalyst. Thus, TiO₂ has unique effects that TiO₂ can forcibly oxidize adhering organic contaminates and can be used as construction materials having a self-cleaning power, which can be cleaned only by irradiation with light, various filters or reaction catalysts.
MnO, Fe₂O₃ and ZnO are useful as a dark coloring material, a light coloring material, and a white coloring material, respectively.
These oxides may be contained alone in the amorphous material.
The composition of the above-mentioned amorphous material preferably contains the following as weights in terms of Al₂O₃, SiO₂ and CaO: Al₂O₃: 3 to 51% by weight of the total weight of the composite hardened product, SiO₂: 6 to 53% by weight of the total weight of the composite hardened product, CaO: 6 to 63%, desirably 8 to 63% by weight of the total weight of the composite hardened product, and the total thereof: not more than 100% by weight.
If the content of Al₂O₃ is below 3% by weight or over 51% by weight, the strength of the composite hardened product drops. If the content of SiO₂ is below 6% by weight or over 53% by weight, the strength of the composite hardened product also drops. If the content of CaO is below 8% by weight or over 63% by weight, the strength of the composite hardened product also drops.
Furthermore, in order to obtain the hardened product having a large strength, it is advantageous that in terms of oxides the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are adjusted to 0.2-7.9 and 0.2-12.5, respectively.
It is optimal that the ratio of CaO/SiO₂ is over 0.2 and 7.9 or less and the ratio of CaO/Al₂O₃ is over 0.2 and 12.5 or less. These amounts of Ca, Al and Si (CaO, Al₂O₃ and SiO₂ converted amounts) are the total amounts of Ca, Al and Si in the composite hardened product. For example, in the case of Ca, the amount thereof is the amount of calcium carbonate and all Ca in the inorganic amorphous material.
In the case that the composite hardened product contains one or more selected from Na₂O, MgO, P₂O₅, SO₃, K₂O, TiO₂, MnO, Fe₂O₃ and ZnO as oxides other than Al₂O₃, SiO₂ and CaO, preferred contents of the respective components are as follows. Of course, the total amount of these oxides is not over 100% by weight.
Na₂O: 0.1 to 1.2% by weight of the total weight of the composite hardened product,
MgO: 0.3 to 11.0% by weight of the total weight of the composite hardened product,
P₂O₅: 0.1 to 7.3% by weight of the total weight of the composite hardened product,
SO₃: 0.1 to 3.5% by weight of the total weight of the composite hardened product,
K₂O: 0.1 to 1.2% by weight of the total weight of the composite hardened product,
TiO₂: 0.1 to 8.7% by weight of the total weight of the composite hardened product,
MnO: 0.1 to 1.5% by weight of the total weight of the composite hardened product,
Fe₂O₃: 0.2 to 17.8% by weight of the total weight of the composite hardened product, and
ZnO: 0.1 to 1.8% by weight of the total weight of the composite hardened product
The reason why the contents of the these oxides are limited to the above-mentioned ranges is that the strength of the composite hardened product drops if the contents depart from the above-mentioned ranges.
It can be checked whether or not the composite hardened product has an amorphous structure. That is, if a halo is observed in the range of 2 = 10° to 40° by X-ray diffraction, it can be verified that the hardened product has an amorphous structure. In this invention, the hardened product may have a complete amorphous structure, or may have a structure wherein a crystal substance made of the following is intermixed with an amorphous structure: hydrogen aluminum silicate, kaolinite, zeolite, gehlenite, syn, anorthite, melitite, gehlenite-synthetic, tobermorite, xonotlite, ettringite, oxides such as SiO₂, Al₂O₃, CaO, Na₂O, MgO, P₂O₅, SO₃, K₂O, TiO₂, MnO, Fe₂O₃ and ZnO, and CaCO3 (calcite).
These crystal substances cannot be considered to be strength-exhibiting materials per se, but can be considered to have effects of making the hardness and the density high to improve the compressive strength and suppress the development of cracks. The content of the crystal substances is desirably from 0.1 to 50% by weight of the total weight of the composite hardened product. This is because if the amount of the crystal substances is less than 0.1% by weight, it is impossible to obtain sufficiently the effects of making the hardness and the density high to improve the compressive strength and suppress the development of cracks, and if the amount is over 50% by weight, a drop in the bending strength is caused.
The crystalline compound of the Al₂O₃-SiO₂ system is hydrogen aluminum silicate, kaolinite or zeolite; the crystalline compound of the Al₂O₃-CaO system is calcium aluminate; the crystalline compound of the CaO-SiO₂ system is calcium silicate; the crystalline compound of the Al₂O₃-SiO₂-CaO system is gehlenite, syn, or anorthite; and the crystalline compound of the Al₂O₃-SiO₂-CaO-MgO is melitile, or gehlenite-synthetic.
Furthermore, as the above-mentioned crystal substances, materials containing Ca are preferred. Preferred are also materials containing gehlenite, syn (Ca₂Al₂O₇), melitie-synthetic (Ca₂(Mg_0.5Al_0.5)(SiO_1.5Al_0.5O₇)), gehlenite-synthetic (Ca₂(Mg _0.25Al_0.75)(Si_1.25Al_0.75O ₇)), anorthite, ordered (Ca₂Al₂Si₂O₈), or calcium carbonate (calcite).
In the composite hardened product produced by the production process of this invention, halogen may be added to the amorphous materials made of the system of at least two oxides. This halogen becomes a catalyst for generation reaction of solid-solution and hydrate, and also functions as burning-controlling material. The content thereof is desirably from 0.1 to 1.2% by weight. This is because if the content is below 0.1% by weight, the strength is low, and if the content is over 1.2% by weight, harmful substances are generated by burning. As the halogen, chlorine, bromine or fluorine is desired.
In the same way, calcium carbonate (calcite) may be added. Calcium carbonate itself is not a strength-exhibiting material, but it can be considered that by surrounding the periphery of calcium carbonate by the amorphous material, calcium carbonate contributes to an improvement in the strength by the effect of blocking the development of cracks, or the like effect. The content of this calcium carbonate is desirably 48% or less by weight of the total weight of the composite hardened product. This is because if the content is over 48% by weight, the bending strength drops. The content is desirably 0.1% or more by weight. If the content is below 0.1% by weight, calcium carbonate does not contribute to the improvement in the strength.
Furthermore, in order to improve the strength still more or improve the water-resistance, chemical-resistance and fireproofing performance, it is advantageous to add a binder. This binder desirably comprises either of a thermosetting resin or an inorganic binder, or both thereof. As the thermosetting resin, desired is at least one resin selected from phenol resin, melamine resin, epoxy resin and urea resin. As the inorganic binder, desired is at least one selected from the group comprising soda silicate, silica gel and alumina sol.
Next, as the organic fibrous material which is intermixed with the inorganic amorphous material in the composite hardened product producing process of this invention, an organic fibrous material comprising a polysaccharide is used. This is because the polysaccharide has OH groups and is easily bonded to various compounds of Al₂O₃, SiO₂ or CaO through hydrogen bonds.
The polysaccharide is desirably at least one compound selected from aminosugar, uronic acid, starch, glycogen, inulin, lichenin, cellulose, chitin, chitosan, hemicellulose, and pectin. As the organic fibrous material comprising these polysaccharides, a pulverized product of pulp, pulp waste, or wastepaper of newspaper or magazines is advantageously adapted.
The content of the fibrous material is desirably from 2 to 75% by weight. This is because if the content is below 2% by weight, the strength of the composite hardened product drops, and if the content is over 75% by weight, it may be feared that the fireproofing performance, water-resistance, dimensional stability and the like deteriorates.
The average length of the fibrous material is desirably from 10 to 1000 µm. If the average length is too short, no entanglement is generated. If the average length is too long, voids are generated so that the strength of the composite hardened product drops easily.
The above-mentioned composite hardened product 1 is optimally a product obtained by drying, condensing and hardening paper sludge (scum). That is, papermaking sludge is pulp waste containing inorganic materials, contains organic fibrous materials, and is inexpensive because of the use of industrial wastes as the ingredient thereof. Thus, the papermaking sludge contributes to solution of environmental problems. Additionally, this papermaking sludge itself has a function as a binder, and has an advantage that the sludge itself or a kneaded product obtained by mixing the sludge with some other industrial waste can be fashioned into a desired shape.
In general, the papermaking sludge contains not only pulp but also water and at least one selected from crystals of Al₂O₃, SiO₂, CaO, Na₂O, MgO, P₂O₅, SO₃, K₂O, TiO₂, MnO, Fe₂O₃ and ZnO, or sol products of precursors of these oxides, or composites thereof, halogens, and calcium carbonate.
As illustrated in FIG. 2, in order to improve the fireproofing performance or improve the strength by the formation of a strength-exhibiting material resulting from reaction with the amorphous material, it is advantageous to intermix inorganic particles 4 with the composite hardened product 1. By adjusting the amount of the inorganic particles, the specific gravity of the composite hardened product can be adjusted.
As the inorganic particles 4, there can be used at least one selected from calcium carbonate, calcium hydroxide, volcanic soil, volcanic soil balloon, perlite, aluminum hydroxide, silica, alumina, talc, calcium carbonate, and industrial waste powder. As the industrial waste powder, it is particularly desired to use at least one industrial waste powder selected from fired powder of papermaking sludge, glass-polished rubbish, and silica sand pulverized rubbish. This is because the use of the industrial waste powder makes it possible to attain low costs and contribute to a solution of an environmental problem.
The inorganic particles of the fired papermaking sludge can be obtained by heat-treating papermaking sludge at 300 to 1500 °C. The thus obtained inorganic particles are amorphous and have good strength and toughness and small density. Therefore, by dispersing them into the composite hardened product, the product can be made light. The inorganic particles obtained in the case that papermaking sludge is fired at 300 °C or more and not more than 800 °C and obtained by heat-treating papermaking sludge at 300 to 1500 °C and subsequently quenching it contain an amorphous material surely. Thus, the inorganic particles are advantageous.
The specific surface area of the inorganic particles 4 is desirably from 0.8 to 100 m²/g. If it is below 0.8 m²/g, the contact area between the amorphous material and the inorganic particles becomes small so that the strength drops. If it is over 100m²/g, effects such as crack-development and hardness-improvement fall so that the strength drops.
Furthermore, the inorganic particles 4 desirably contain at least one inorganic material selected from silica, alumina, iron oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide and phosphorus pentaoxide. These are chemically stable and excellent in antiweatherability, and have properties desired for industrial materials such as construction materials.
Since the average particle diameter of the inorganic particles 4 is too small or too large, sufficient strength cannot be obtained. Therefore, it desirably ranges from 1 to 100 µm. The content of the inorganic particles desirably ranges from 10 to 90% by weight. That is, if the amount of the inorganic particles is too large, the strength drops, and if the amount of the inorganic particles is too large, the hardened product becomes brittle. In either case, the strength thereof drops.
The composite hardened product 1 produced by the process of this invention is used in various industries, and can be used as a new construction material instead of a calcium silicate board, a perlite board, a veneer board, a plaster board or the like, or a medical material for an artificial leg, an artificial bone or an artificial dental root, or an electronic material such as a core substrate or an interlayer resin insulating layer of a print circuit board, or the like.
Referring to FIGs. 3-9, the following will describe embodiments of the hardened product producing process and the hardened product producing machine of this invention.
In the producing process of this invention, papermaking sludge is used, as the ingredient of the composite hardened product, without being kneaded with other industrial wastes. As the papermaking sludge used in the producing process of this invention, desirable is papermaking sludge discharged in a pulp-producing step in the manufacture of printing/information paper, craft paper, titanium paper, tissue paper, toilet paper, sanitary products, towel paper, hybrid paper for industries, hybrid paper for home use, or the like, a step of treating an ingredient such as waste paper, a papermaking step, or the like step. The papermaking sludge is handled by Maruto Yozai-sha.
FIG. 3 illustrates the whole of a hardened product producing machine. The hardened product producing machine is composed of an ingredient preparing mechanism 10 for preparing papermaking sludge and generating a slurry 14, a papermaking mechanism 20 for producing a papermaking product 26 from the slurry 14 in a papermaking manner, a reversing device 40 for reversing the papermaking product 26, a pressing device 50 for forming the papermaking product 26 into a lamination and then pressing and dehydrating the lamination, and a drier 60 for drying the pressed papermaking product to form a hardened product 1.
Referring to FIG. 4(A), the ingredient preparing mechanism 10 for preparing the ingredient will be firstly described. The ingredient 11 and water 12 are weighed by suction dehydration, which will be described later, in such a manner that the concentration of solid content is from 0.5 to 25% by weight. They are then put into a mixer 13. Thereto are added a flocculating agent (flocculating agent, added amount: 0.01 to 5%) made of any one of aluminum sulfate, ferric chloride, polyaluminum chloride, sodium polyacrylate, polymethacrylate, polyacryalte, and polyacrylamide, and an organic fiber such as a vinylon fiber (binder, added amount: 0.1 to 10% by weight). They are mixed in the mixer 13 to prepare the slurry 14. It is possible to use, as the organic fiber (binder), synthetic fiber such as polyethylene, polypropylene or vinylon, pulp, pulp recovered from waste paper, fibrous industrial waste or the like. Concerning the ingredient, various inorganic powders or resins may be further added to the papermaking sludge.
A dehydrating container 15 having, at its bottom, a filter 16 is used to subject this slurry 14 to suction dehydration. By the suction dehydration, the concentration of the solid content is made to 0.5 to 25% by weight. In the suction dehydration, the fibers of the papermaking sludge are not oriented; therefore, no warps or cracks are generated in the resultant hardened product.
The bottom of this dehydrating container 15 is connected to a vacuum pump 17, and water content is sucked by the operation of the vacuum pump 17. The filter 16 is not particularly limited, and it is possible to use a sintered metal, a porous metal plate (metal plate wherein holes having a diameter of 1 to 5 mm are made), a porous ceramic filter, a porous resin, a glass fiber plate or the like. The ingredient 14 whose water content is adjusted in the dehydrating container 15 is temporarily stored in a chest tank 18. The chest tank 18 is provided with a stirring propeller so that the solid content in the ingredient does not precipitate.
In the present embodiment, the water content is adjusted in the dehydrating container 15. However, as illustrated in FIG. 4(B), the water content can be adjusted on the basis of only the amount of water added to the mixer 13 without the use of the dehydrating container 15.
Subsequently, the papermaking product 26 is produced from the slurry 14 containing the papermaking sludge whose water content is adjusted in the papermaking mechanism 20. An inorganic binder such as cement or an organic binder such as resin may be added to the slurry (ingredient solution). Referring to FIG. 5, this papermaking mechanism 20 will be described. The papermaking mechanism 20 has a series of three vats 21A, 21B and 21C for storing the slurry 14, wire cylinders 22A, 22B and 22C, arranged in the vats, for producing the slurry 14 in a papermaking manner, and a carrying belt 23 for transferring the papermaking product 26 produced in the papermaking manner in the wire cylinders 22A, 22B and 22C and then carrying the papermaking product, a cutting rotary drum 30 for winding the papermaking product 26 carried on the carrying belt 23 so as to have a given thickness, and then cutting the product, a cutter 36 for cutting the papermaking product 26, and a belt conveyor 38 for carrying the papermaking product 26.
The wire cylinders 22A, 22B, and 22C are formed to have a diameter of 70 cm and a width of 1 mm. In the present embodiment, a drainage body for drainage (papermaking) is a rotary drum (wire cylinder) composed of a netlike body; therefore, the papermaking product 26 can be continuously produced in the papermaking manner from the ingredient solution 14. Thus, the hardened product can be effectively mass-produced from the papermaking sludge. Water which has penetrated through the wire cylinders 22A, 22B and 22C is returned to the mixer 13 illustrated in FIG. 4(A) through a pipe 17a and the vacuum pump 17.
In the present embodiment, the three wire cylinders 22A, 22B and 22C are lined up along the carrying belt 23, and the papermaking product 26 is transferred onto the carrying belt while it is formed into a multilayer. For this reason, the papermaking product 26 can be effectively produced from the ingredient solution 14 in the papermaking manner so that the hardened product can be effectively mass-produced from the papermaking sludge. In the present embodiment, the rotation number of the wire cylinders is set to 60 rotations/minute. This rotation number is desirably from 1 to 100 times/minute. This is because the papermaking product 26 can be effectively produced from the ingredient solution 14 in the papermaking manner so that the hardened product can be effectively mass-produced from the papermaking sludge. If the rotary drum is lower than 1 rotation/minute, papermaking efficiency is low. On the other hand, if the rotation number is over 100 rotations/minute, the papermaking product having a uniform thickness cannot be easily produced. In the present embodiment, the three wire cylinders 22A, 22B and 22C are lined up but the number of the wire cylinders may be one or more.
Meshes of the wire cylinders 22A, 22B and 22C are formed into #60 (mesh number per one inch: 60). The meshes of the wire cylinders 22A, 22B and 22C are desirably from #40 to 150. This is because the papermaking product 26 can be effectively produced from the ingredient solution (slurry) 14 in the papermaking manner so that the hardened product having a high density can be effectively mass-produced. If the meshes are rougher than #40, only the inorganic amorphous material falls out from the ingredient solution so that the density and the strength of the hardened product drop. On the other hand, if the meshes are finer than #150, the falling-out of water content deteriorates so that the papermaking product cannot be effectively produced from the ingredient solution in the papermaking manner. Since flocks are generated in the papermaking sludge (ingredient solution) by the flocculating agent, the papermaking can be effectively performed.
Concerning the concentration of the ingredient solution containing the papermaking sludge, solid content is desirably from 3.5 to 25% by weight. This is because the property of papermaking from the papermaking sludge can be improved and the hardened product can be effectively mass-produced. That is, if the concentration is below 3.5% by weight, the papermaking cannot be effectively performed from the ingredient solution, using the wire cylinders (drainage bodies), and if it is over 25%, the uniformity of the finished products drops.
The carrying belt 23 for transferring and carrying the papermaking product produced in the wire cylinders 22A, 22B and 22C is made of a felt having a width of 1 m, and is tensed around a roller 34. The back surface of the belt 23 is provided with an sucking box 24 and the box performs dehydration while a vacuum pump 17 performs suction. That is, the belt 23 adsorbs water content of the ingredients 24 containing the papermaking sludge into pores of the felt, and the adsorbed water content is adsorbed into the side of the vacuum pump 17 through the adsorbing box 24 and is returned to the mixer 13 illustrated in FIG. 4(A). In this first embodiment, the belt 23 is composed of the belt 23, but it is possible to use, instead of this, a belt obtained by hardening a porous resin, a porous rubber, or an inorganic fiber having continuous pores with a binder, a belt obtained by hardening a sintered metal, a porous metal or porous metal blocks with a binder having flexibility, such as a rubber, or the like belt. In the present embodiment, the carrying belt 23 is composed of a porous body having continuous pores, and dehydration is performed while the papermaking product is carried on the carrying belt 23. Therefore, water content in the papermaking product 26 can be effectively reduced.
In the present embodiment, the carrying speed of the carrying belt 23 is set to 48 m/minute. In synchronization with this, the wire cylinders 22A, 22B and 22C, the cutting rotary drum 30, and the belt conveyor 38 are driven by a non-illustrated motor. The carrying speed of the carrying belt 23 is desirably from 5 to 80 m/minute. This is because the papermaking product having an appropriate thickness can be efficiently produced from the ingredient solution in the papermaking manner so that the hardened product can be efficiently mass-produced. If the carrying speed is lower than 5 m/minute, the papermaking product can be made thick but papermaking efficiency is bad. On the other hand, if the carrying speed is over 80 m/minute, the papermaking product becomes thin. Consequently, it is difficult to make the thickness thereof uniform, and the papermaking product may cleave.
The cutting rotary drum 30 for winding the papermaking product carried on the carrying belt 23 up to a given thickness and cutting the papermaking product is formed to have a diameter of 64 cm (outer circumference: 2 m), and has, on the surface thereof, a storing groove 32 for storing water, and a piano wire 31 accommodated in an accommodating groove 33 positioned near this groove 32. The cutting rotary drum 30 causes the papermaking product 26 carried from the carrying belt 23 to be wounded on the surface thereof while the drum 30 causes the papermaking product 26 to be formed into a multilayer.
When the thickness of the papermaking product 26 reaches the given thickness (1.5 cm) and this is detected by a non-illustrated sensor, the piano wire 31 in the accommodating groove 33 is pushed out. At the position near the storing groove 32, the water content in the papermaking product 26 is high. When the piano wire 31 is pushed out, the papermaking product is cut along the storing groove 32 so that one cut end thereof falls down to the side of the belt conveyor 38. With the rotation of the cutting rotary drum 30 and the carrying of the belt conveyor 38, the papermaking product 26 having the given thickness is carried onto the belt conveyor 38 (see FIG. 6(B)). As illustrated in FIG. 6(C), when the other cut end is carried to the position corresponding to the cutter 36, the cutter 36 is taken down to the side of the belt conveyor 38 so that the cut end of the papermaking product 26 and the papermaking product which is carried on the carrying belt 23 and has not been formed into any lamination are separated form each other.
In the present embodiment, the papermaking product on the carrying belt 23 is formed into a multilayer while being transferred onto the cutting rotary drum 30, and then multilayered papermaking 26 is cut to have a given size when the thickness of the papermaking product 26 reaches a given thickness. Since the papermaking product 26 having a uniform thickness (1.5 cm) and a uniform size (1m × 2 m) can be continuously fashioned by the cutting rotary drum, the hardened product can be effectively mass-produced.
The present embodiment has the cutter 36 for cutting, at regular intervals, the papermaking product 26 whose end is cut in the cutting rotary drum 30. Therefore, the papermaking product 26 having a given length (2 m) can be effectively formed. In the present embodiment, the thickness of the papermaking product 26 is made to 1.5 cm, but the thickness is desirably 2 cm or less. If the thickness is 2 cm or less, the papermaking is easy and the papermaking product can easily be handled.
Referring to FIG. 7, the reversing device 40 for reversing the papermaking product will be described. In the producing machine of the present embodiment, the papermaking product is formed into the lamination while being alternately reversed, as will be described later. Therefore, the papermaking product 26 is reversed at intervals of every other sheet. The reversing device 40 is composed of a carrying device 42 for adsorbing and carrying the papermaking product, a table 44, and a reversing plate 46.
As illustrated in FIG. 7(A), the papermaking product 26 on the belt conveyor 38 is put onto the reversing plate 46 by the carrying device 42. The reversing plate 46 is driven to reverse the papermaking product 46 (see FIG. 7(B)). As illustrated in FIG. 7(C), the reversed papermaking product 26 is carried to the pressing device 50 illustrated in FIG. 3 by means of the carrying device 42. As described above, in the present embodiment, the papermaking product 26 is made flexible by adding the binder to the slurry 14. Thus, the handling thereof after the cutting is made easy.
Referring to FIGs. 8 and 9, the pressing device 50 for pressing and dehydrating the papermaking product will be described. As illustrated in FIG. 8(A), the pressing device 50 is composed of a female mold 54 having a concave 54A and a male mold 52 which is fitted into the concave 54A. Very small holes 54a and 52a for discharging water content generated when the papermaking product is pressed are made in the female mold 54 and the male mold 52, respectively. The pressing device 50 is provided with a curtain coater 56 for coating the papermaking product 26 with the ingredient solution 14 (see FIG. 8(B)).
Laminating and pressing in the pressing device 50 will be described. As illustrated in FIG. 8(A), the papermaking product 26 is first carried as the lowermost layer into the concave 54A of the female mold 54. At this time, the papermaking product 26 is reversed by the reversing device 40 above-mentioned with reference to FIG. 7(C) so that the contact surface thereof with the cutting rotary drum 30 is directed downwards. Next, the ingredient solution 14 is applied to the upper face of the papermaking product 26, that is, to the face adhering to the upper papermaking product, by the curtain coater 56 as illustrated in FIG. 8(B). Concerning the amount of this ingredient solution, the solid content thereof is preferably form 50 to 500 g/m² per layer of the papermaking product. The curtain coater 56 is used herein, but various applying devices such as a roll coater may be used.
As the papermaking product of a second layer, the papermaking product 26 on the belt conveyor 38 is carried, without being reversed, into the concave 54A of the female mold 54 by the carrying device 42, as illustrated in FIG. 8(C). Thereafter, as illustrated in FIG. 9(A), the ingredient solution 14 is applied thereto and then the reversed papermaking product of a third layer is put thereon. The ingredient solution 14 is applied thereto, and then the non-reversed papermaking product 26 of a fourth layer (topmost layer) is put thereon. As a result, the laminating is completed. The four layers are laminated herein, but two or more layers may be laminated. In the case that a thin hardened product is produced, only one layer may be used.
Thereafter, the female mold 52 is pushed down and pressing is performed at 60 kg/cm² (see FIG. 9(B)). At this time, the water content exuding from the papermaking product 26 is discharged through the holes 54a and 52a. Subsequently, the male mold 52 is raised (see FIG. 9(C)), and the composite hardened product 1 formed by the pressing is taken out from the female mold and carried to the drier 60.
In the present embodiment, the pressing is performed in the mold frame (concave 54A); therefore, papermaking product 26 does not cleave even if it is pressed at a high pressure. Thus, the hardened product having a high strength can be produced with a high yield from the papermaking sludge. Since the male mold 52 and the female mold 54 have the holes 52a and 54a for pulling out the water content exuding from the papermaking product 26, dehydration is performed at the time of the pressing so that a subsequent hardening step based on drying can be completed in a short time. Since the papermaking product of the papermaking sludge is formed into the lamination between the respective layers of which the ingredient solution 14 are interposed, a multilayered hardened product causing no exfoliation can be produced.
Preferably, the pressing is performed at a pressure of 10 to 250 kg/cm². If the pressing is performed at a pressure of less than 10 kg/cm², a required strength cannot be obtained. On the other hand, if the pressing is performed at a pressure of more than 250 kg/cm², the strength cannot be made high so that the pressing device becomes large-sized and expensive.
In the present embodiment, the papermaking product of the papermaking sludge obtained by subjecting the ingredient solution to the papermaking manner using the wire cylinders (drainages) is formed into the lamination. Since it is ineffective to obtain a thick papermaking product in any papermaking manner, a thin papermaking product is effectively produced in the present papermaking manner from the papermaking sludge and is formed into the lamination, thereby producing a hardened product having required strength and thickness. In this way, the hardened product can be effectively mass-produced from the papermaking sludge.
In the producing process of the present embodiment, the papermaking sludge is effectively produced in the papermaking manner by forming the papermaking product to have a thickness of 20 mm or less, and the hardened product having required strength and thickness is produced by forming the papermaking product into the lamination. For this reason, the hardened product can be effectively mass-produced from the papermaking sludge.
In the present embodiment, the papermaking product 26 is formed into the lamination while the laminating face thereof is alternately made reverse. That is, the papermaking product 26 is formed into the lamination while the direction that a warp is generated is made reverse; therefore, no warp or delamination is generated in the hardened product 1 wherein the papermaking product 26 is formed into the lamination. Concerning the papermaking products of the topmost layer and the lowermost layer, their naked faces are made to faces contacting the rotary drum and the face having unevenness and contacting the carrying belt 32 made of the felt is made inside; therefore, the surface of the hardened product made of the lamination can be made smooth.
Furthermore, in the present embodiment, the flocculating agent is added to the ingredient solution containing the papermaking sludge so that the solution is flocculated; therefore, the hardened product 1 having a uniform specific gravity (the range of 1.2 to 1.3) can be mass-produced from the papermaking sludge. Additionally, in the present embodiment, the laminating is performed in the female mold 54; therefore, it is unnecessary to transport the papermaking product of the lamination. Thus, the present embodiment is suitable for mass-production. In the present embodiment, the laminating is performed in the mold frame 54, but the papermaking product may be transported into the mold frame after the laminating.
The papermaking product is pressed, dehydrated and dried in the pressing device 50 to lower the water content. Subsequently, the papermaking product is completely dehydrated in the drier 60 illustrated in FIG. 3 to advance hardening reaction. The drier 60 has an electric heater 62 and a fan 64, and causes drying at a temperature of 80 to 200 °C. The drier 60 has the electric heater 62, but instead of this an infrared heater, vapor, a solar drier or the like can be used.
The hardened product 1 undergoing the drying step is further carried and is cut into a given size by means of a non-illustrated cutting means. The cutting is performed by a cutter arranged on the conveyor, a saw or the like. The cut composite hardened product 1 is finally subjected to an examination of a warp or the like in a non-illustrated examining device. As the examining device, an X-ray sensor, an infrared sensor or the like can be used. It may be examined in an image-processing device or the like whether a break or a crack is generated or not.
Referring to FIGs. 10 and 11, a relationship between the papermaking product-laminating direction (adhering direction) and the generation of delamination will be described.
FIG. 10 (A) illustrates, on the right side thereof, a case in which the papermaking products 26 are made reverse and the faces contacting the felt constituting the carrying belt are adhered to each other. In the papermaking products 26, stress remains when they are wounded around the cutting rotary drum 30 illustrated in FIG. 3. Thus, the products 26 warp along the winding direction after cutting. The left side in the figure shows a section of the laminated papermaking products 26. Unevenness in the figure shows the felt-contacting faces. In the present embodiment, the adhering direction in FIG. 10(A) is shown.
FIG. 10(B) shows a case in which the papermaking products 26 are adhered to each other without being made reverse. FIG. 10(C) shows a case in which the papermaking products 26 are made reverse and then faces contacting the cutting rotary drum are adhered to each other.
FIG. 11 is a graph table showing a relationship between the papermaking product adhering direction and the generation of delamination, and a relationship between pressure in the pressing device and strength.
In the graph table, applied amount shows the applied amount of the ingredient solution 14 between the papermaking products; pressure, pressure in the pressing device; time, pressing time; density, the density of the hardened product before drying; and maximum load, load which the hardened product after the drying can resist, that is, the strength thereof. Water content is a value after the pressing. Shrinkage ratio thickness shows shrinkage ratio in the thickness direction; shrinkage ratio length, shrinkage ratio in the length direction; and shrinkage ratio width, shrinkage ratio in the width direction. Five papermaking products are laminated herein. Exfoliated layer number shows the number of exfoliated layers out of the 5 layers; exfoliated side number, the number of exfoliated corners out of 4 corners; and the exfoliation length, the total length of portions where exfoliation was generated.
It can be firstly understood that by making the pressure high, the maximum load can be made high. It can also be understood that by adopting "A" shown in FIG. 10(A) as the adhering direction and applying a pressure of 60 kg/cm², delamination can be completely prevented (see No. 9). Since the papermaking sludge is used as the ingredient in the present embodiment, the shrinkage ratio is large. Thus, at the time of the drying, the stress remaining when the papermaking products are wound around the cutting rotary drum 30 acts so that exfoliation is easily generated. However, by making the papermaking products reverse and adhering them to each other, the exfoliation can be prevented. In the present embodiment, the papermaking products are made reverse at intervals of every other layer. However, by making the papermaking products reverse at intervals of every 2 layers, or every 3 layers and laminating the layers, a warp or delamination can be prevented.

(1) Case in which the amount of Si, Al or Ca was changed

The following will describe one example wherein the composite hardened product obtained in the above-mentioned step was analyzed using a fluorescent X-ray analyzing device (RIX2100, made by Rigaku Corp.).

Example 1-1

It was found out that the hardened product had the following composition in term of oxides. Concerning pulp, the amount thereof was measured from the amount of a reduction in the weight resulting from firing at 1100 °C.

	Notes
Pulp: 51.4% by weight,	SO₃: 0.5% by weight
SiO₂: 24.2% by weight,	P₂O₅: 0.2% by weight
Al₂O₃: 14.0% by weight,	Cl: 0.2% by weight
CaO: 8.0% by weight,	ZnO: 0.1% by weight
MgO: 1.4% by weight,	Others: very small
TiO₂: 1.0% by weight,

Example 1-2

Prepared was 1500 g of a papermaking sludge which had not been fired (a papermaking sludge "Raw sludge" of fine quality paper for OA equipment made by Maki Seishi Kabushiki Kaisha and handled by Maruto Yozai-sha, solid content: 51% by weight, and water content: 49% by weight). This was produced in the papermaking manner as in Example 1.
The fluorescent X-ray analyzing device (RIX2000, made by Rigaku Corp.) was used to analyze the composition. The values in terms of oxides are shown below. The amount of pulp was measured from the amount of a reduction in the weight resulting from firing at 1100 °C. A peak of calcium carbonate was observed according to the X-rays. The composition also contains the amount of calcium carbonate.

The amount of calcium carbonate was measured by preparing a calibration curve from the height of a maximum peak near 2 = 29° in the X-ray diffraction chart and the content of calcium carbonate. Since any calibration curve depends on devices, it is necessary to re-prepare a calibration curve when a diffraction test is performed in a different device. In the present application, miniFlex made by Rigaku Corp. was used. As a result, the amount was about 11% by weight. It was presumed from mapping images of Ca and O according to the fluorescent X-rays that the crystal habit of calcium carbonate was in a spindle form.
Composition of the papermaking sludge hardened product of Example 1-2

Pulp: 53.1% by weight	MgO: 1.3% by weight
SiO₂: 15.7% by weight	SO₃: 0.8% by weight
Al₂O₃: 9.7% by weight	P₂O₅: 0.8% by weight
CaO: 16.3% by weight	Cl: 0.3% by weight
TiO₂: 1.2% by weight	ZnO: 0.6% by weight
FeO: 0.2% by weight
Others: very small

Example 1-3

To 1500 g of a papermaking sludge which had not been fired (a papermaking sludge "Raw sludge" of fine quality paper for OA equipment made by Maki Seishi Kabushiki Kaisha and handled by Maruto Yozai-sha, solid content: 51% by weight, and water content: 49% by weight) was added 73 g of spindle form light calcium carbonate (Tamapearl TP-121 made by Okutama Kogyo Kabushiki Kaisha, average diameter: 2 µm). This was produced in the papermaking manner as in Example 1.
Composition of the papermaking sludge hardened product of Example 1-3

Pulp: 50.4% by weight	MgO: 1.2% by weight
SiO₂: 14.9% by weight	SO₃: 0.7% by weight
Al₂O₃: 9.2% by weight	P₂O₅: 0.7% by weight
CaO: 20.6% by weight	Cl: 0.3% by weight
TiO₂: 1.0% by weight	ZnO: 0.6% by weight
FeO: 0.2% by weight
Others: very small

Example 1-4

To 1500 g of a papermaking sludge which had not been fired (a papermaking sludge "Raw sludge" of fine quality paper for OA equipment made by Maki Seishi Kabushiki Kaisha and handled by Maruto Yozai-sha, solid content: 51% by weight, and water content: 49% by weight) was added 219 g of columnar light calcium carbonate (Tamapearl TP-123 made by Okutama Kogyo Kabushiki Kaisha, average diameter: 2 µm).

The fluorescent X-ray analyzing device (trade name: RIX2100, made by Rigaku Corp.) was used to analyze the composition. The content of calcium carbonate was measured. As a result, it was about 30.8% by weight.
Composition of the papermaking sludge hardened product of Example 1-4

Pulp: 45.7% by weight	MgO: 1.1% by weight
SiO₂: 13.5% by weight	SO₃: 0.7% by weight
Al₂O₃: 8.4% by weight	P₂O₅: 0.7% by weight
CaO: 27.9% by weight	Cl: 0.3% by weight
TiO₂: 1.0% by weight	ZnO: 0.5% by weight
FeO: 0.1% by weight
Others: very small

Example 1-5

One hundred three parts by weight of a fired product of a papermaking sludge (trade name "Cyclone ash" made by Maruto Yozai-sha) and 1209 parts by weight of the papermaking sludge which had not been fired in Example 1-1 were kneaded.
Next, a composite hardened product was produced in the same manner as in Example 1.
The composition of the fired sludge was analyzed using the fluorescent X-ray analyzing device (RIX2100, made by Rigaku Corp.). The composition was as follows in terms of respective oxides. The specific gravity was 0.9.

(Fired product of the papermaking sludge)

The composition of the fired product of the papermaking sludge

SiO₂: 34.1% by weight,	MgO: 6.0% by weight
Al₂O₃: 20.7% by weight	P₂O₅: 2.7% by weight
Fe₂O₃: 12.4% by weight	TiO₂: 1.0% by weight
CaO: 21.3% by weight	SO₃: 0.5% by weight
ZnO: 0.1% by weight	Cl: 0.2% by weight
Others: very small

Example 1-6

Ten pieces of core paper wherein craft paper having a weigh of 80 g/cm² was impregnated with a phenol resin were laminated and the resultant lamination was pressed at 80 kg/cm² and 140 °C to produce each decorative laminated sheet. The decorative laminated sheets were bonded to both faces of the hardened product of Example 1 with a vinyl acetate type adhesive agent.

Example 1-7

To the papermaking sludge having the composition of Example 1-2 was added 10% by weight of Portland cement.
The composition of the cement

SiO₂: 22.2% by weight, SO₃: 1.6% by weight

Al₂O₃: 5.1% by weight MgO: 1.4% by weight

CaO: 65.1% by weight

FeO: 3.2% by weight

Others: very small

Example 1-8

Prepared were 3020 parts by weight of a papermaking sludge which had not been fired (low quality paper for OA equipment made by Nakamura Seishi and handled by Maruto Yozai-sha, solid content: 34% by weight, and water content: 66% by weight). Next, 2N hydrochloric acid solution was used to wash the papermaking sludge with the acid to remove Ca components substantially completely. This was called A.

A
Pulp: 51.2% by weight	MgO: 1.6% by weight
SiO₂: 18.6% by weight	SO₃: 3.5% by weight
Al₂O₃: 22.3% by weight	P₂O₅: 0.3% by weight
CaO: 0.0% by weight	Cl: 0.1% by weight
	ZnO: 0.2% by weight
Others: very small

A papermaking sludge of inkjet printing paper made by Maki Seishi Kabushiki Kaisha and handled by Maruto Yozai-sha (solid content: 51% by weight, and water content: 49% by weight) was called B.

B

Pulp: 21.8% by weight SiO₂: 4.6% by weight

Al₂O₃: 7.5% by weight P₂O₅: 0.1% by weight

CaO: 65.0% by weight Na₂O: 0.2% by weight

SO₃: 0.2% by weight

Others: very small
The amount of calcium carbonate was 55% by weight.
To a papermaking sludge of inkjet printing paper made by Maki Seishi Kabushiki Kaisha and handled by Maruto Yozai-sha (solid content: 51% by weight, and water content: 49% by weight) was added 10% by weight of calcium carbonate (cubic shape), and the mixture was called C.

C

Pulp: 15.0% by weight SiO₂: 2.6% by weight

Al₂O₃: 5.5% by weight P₂O₅: 0.1% by weight

CaO: 75.0% by weight Na₂O: 0.2% by weight

SO₃: 0.2% by weight

Others: very small
The amount of calcium carbonate was 65% by weight.
Samples was prepared by mixing the above-mentioned A, B and C appropriately, and hardened product were produced in the same papermaking manner as in Example 1, to measure the bending strength, the compressive strength and the nailing property thereof.
The results are shown in FIGs. 15-18. FIG. 15 shows a relationship between CaO/SiO₂ and the compressive strength, and its vertical axis represents the compressive strength (kg/cm²) and its transverse axis represents the ratio of CaO/SiO₂. FIG. 16 shows a relationship between CaO/Al₂O₃ and the compressive strength, and its vertical axis represents the compressive strength and its transverse represents the ratio of CaO/Al₂O₃. FIG. 17 shows a relationship between the content of CaO and the bending strength/the compressive strength, and its vertical axis represents the bending strength/the compressive strength (kg/cm²), and its transverse axis represents the content of CaO (%). FIG. 18 shows a relationship between the content of CaO and the nail pulling-out strength, and its vertical axis represents the nail pulling-out strength (kg/cm²), and its transverse axis represents the content (%) of CaO. As shown in FIG. 15, when the amounts of Ca, Al and Si are the following in terms of CaO, Al₂O₃ and SiO₂, the hardened products exhibit high compressive strength: the ratio of CaO/SiO₂ is from 0.2 to 7.9. On the other hand, when the ratio of CaO/Al₂O₃ is from 0.2 to 12.5, the hardened products exhibit high compressive strength.

Comparative Example 1-1

Prepared were 1512 g of a papermaking sludge which had not been fired (trade name "Raw sludge" handled by Maruto Yozai-sha, solid content: 34% by weight, and water content: 66% by weight). Next, the papermaking sludge was poured into a mold having an area of 800 mm × 1000 mm. Next, stainless steel plates, punching metal plates, nonwoven fabric were put thereinto and 45 pushing rods whose section was 190 mm square were inserted thereinto. The resultant was pressed for 5 minutes while a pressure of 60 kgf/cm² was applied for a pressure-raising time of 30 minutes. In this way, a sheet body having a thickness of 10 mm was produced. This sheet body was heated at 100 °C to produce a plate form composite hardened product. The specific gravity thereof was 1.2.

The fluorescent X-ray analyzing device (RIX2100 made by Rigaku Corp.) was used to analyze the thus obtained composite hardened product. As a result, it was found out that the hardened product had the following composition in term of oxides. Concerning pulp, the amount thereof was measured from the amount of a reduction in the weight resulting from firing at 1100 °C.

	Notes
Pulp: 51.4% by weight	MgO: 1.4% by weight
SiO₂: 24.2% by weight	SO₃: 0.5% by weight
Al₂O₃: 14.0% by weight	P₂O₅: 0.2% by weight
CaO: 8.0% by weight	Cl: 0.1% by weight
TiO₂: 1.0% by weight	ZnO: 0.1% by weight
Others: very small

The amount of calcium carbonate was 9.8% by weight.

Comparative Example 1-2

The papermaking sludge of Example 1-1 was washed with 1N hydrochloric acid to remove calcium carbonate. Thereafter, 84 g of spherical calcium carbonate (C-90, made by Okutama Kogyo Kabushiki Kaisha, average diameter: 2 µm) was added thereto. The amount thereof was about 11% by weight of solid content. However, according to a papermaking manner, calcium carbonate was hardly taken in the hardened product.

Comparative Example 1-3

To the papermaking sludge of Example 1-2 was added 55% by weight of Portland cement.

Comparative Example 1-4

In Comparative Example 1-4, no dehydrating suction was performed in the carrying belt.

The hardened products obtained in the above-mentioned Example 1 and Comparative Example 1 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 1. Concerning the methods of the tests, the bending strength and the compressive strength were measured according to JIS A 6901 and JIS A 5416, respectively. The workability was judged by cutting with a circular saw for woodwork. Furthermore, about the nailing property, a nail having a diameter of 4 mm and a length of 50 mm was driven, and it was examined whether a crack was generated or not. The fracture toughness was calculated from the length of a crack generated by pressing an indenter against the sample in a Vickers harness meter (MVK-D, made by Akashi Seisaku-syo). Young's module was calculated from a curve from a bending breaking test, and was from 1.4 to 2.7 kgf/cm2. This value was used. Concerning brightness, Munsell color charts were used.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness
	kg/cm²	kg/cm²			MPa • m^1/2
Example 1-1	330	850	Possible	None	3.3	7
Example 1-2	335	860	Possible	None	3.3	7
Example 1-3	340	865	Possible	None	3.3	7.5
Example 1-4	350	870	Possible	None	3.2	7.5
Example 1-5	330	850	Possible	None	3.2	7
Example 1-6	330	850	Possible	None	3.3	7
Example 1-7	310	800	Possible	None	3.1	6
Comparative
Example 1-1	300	850	Possible	None	3.0	4.5
Comparative
Example 1-2	280	790	Possible	None	3.5	4
Comparative
Example 1-3	180	300	Impossible	Observed	2.5	4
Comparative
Example 1-4	310	850	Possible	None	3.0	7

Concerning the composite hardened product of Example 1-1, the crystal structure thereof was examined by X-ray diffraction.
Charts of the X-ray diffraction are shown in FIGs. 12 and 13. In the X-ray diffraction, MiniFlex made by Rigaku Corp. was used, and Cu was used as a target. A gentle hill (halo) was observed in the range of 2 = 15° to 30°, and further a peak representing crystal structure was also observed. Thus, it is found out that the crystal structure was intermixed with amorphous structure. From the peak, crystal (calsite) of calcium carbonate was identified.
As the amount of the cement is smaller and the amount of CaO is larger, the brightness is higher. The brightness is higher in the papermaking manner than in the press manner. In the papermaking manner, calcium carbonate having corners is more easily taken in so that the brightness thereof can be made high.

(2) The following will describe, as Example 2, a case in which the rotation number of the rotary drum was changed.

If the rotation speed of the rotary drum is below 1 time/minute, fibers are oriented in the thickness direction of the papermaking product so that a scattering in the strength is caused. If it is over 100 times/minute, the fibers are oriented in the rotation direction so that the strength is scattered. In Example 2, in the papermaking manner synthetic fibers were taken in. Only by mixing the fibers with the ingredient, higher strength and fracture toughness than obtained by dehydration press were able to be obtained.
This is because the synthetic fibers were lengthened and taken in the hardened product.

Production conditions in Example 2 and Comparative Example 2 are as follows. Five papermaking products were overlapped with each other, and made reverse and laminated into a multilayer.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Rotation speed times/minute
Example 2-1	95%	3%	0%	2%	2.0
Example 2-2	90%	2%	5%	3%	20
Example 2-3	98%	0.1%	0%	1.9%	40
Example 2-4	80%	0.02%	15%	4.98%	50
Example 2-5	70%	3%	25%	2%	60
Example 2-6	90%	2%	0%	8%	80
Example 2-7	65%	5%	28%	2%	100
Comparative
Example 2-1	95%	0%	0%	5%	0.8
Comparative
Example 2-2	95%	0%	0%	5%	105

In Comparative Example 2-2, the papermaking products were not made into a multilayer, and the papermaking products of 20 mm were used.

The hardened products obtained in the above-mentioned Example 2 and Comparative Example 2 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 3. Concerning the warp amount, the maximum warp amount of the hardened product having a length of 1 m was measured.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness
	kg/cm²	kg/cm²			MPa • m^1/2
Example 2-1	330	850	Possible	None	3.3	7
Example 2-2	335	860	Possible	None	3.3	7
Example 2-3	340	865	Possible	None	3.3	7
Example 2-4	308	800	Possible	None	3.1	5.5
Example 2-5	310	800	Possible	None	3.1	5.5
Example 2-6	330	850	Possible	None	3.3	7
Example 2-7	310	800	Possible	None	3.3	5.0
Comparative
Example 2-1	270	850	Possible	None	3.0	7
Comparative
Example 2-2	375	850	Possible	None	3.0	7

Scattering %
Example 2-1	1.5
Example 2-2	1.5
Example 2-3	2.0
Example 2-4	1.8
Example 2-5	2.0
Example 2-6	2.0
Example 2-7	1.8
Comparative
Example 2-1	8.9
Comparative
Example 2-2	9.0

(3) The following will describe Example 3 in which the meshes of the rotary drum were changed.

If the meshes of the rotary drum are rougher than #40, only an inorganic amorphous material falls out from the ingredient solution so that the density and the strength of the hardened product drop. On the other hand, if the meshes are finer than #150, the falling-out of water content deteriorates so that no papermaking product can be effectively produced from the ingredient solution in the papermaking manner. Since water content remains so that voids are generated by drying, the density drops. If the meshes are below #40 (that is, rough meshes), calcium carbonate, which gives whiteness, cannot be taken in. If the meshes are over #150 (that is, fine meshes), impurities are taken in. In either case, the brightness drops.

The composition of solid content and meshes in Example 3 and Comparative Example 3 are as follows.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Solid content	Mesh
Example 3-1	95%	3%	0%	0.5%	4%	40
Example 3-2	90%	2%	5%	3%	5%	50
Example 3-3	98%	0%	0%	2%	10%	70
Example 3-4	80%	0%	15%	5%	15%	90
Example 3-5	70%	3%	20%	2%	5%	100
Example 3-6	90%	2%	0%	8%	25%	120
Example 3-7	65%	3%	30%	2%	25%	150
Comparative
Example 3-1	95%	3%	0%	0%	3%	10
Comparative
Example 3-2	95%	3%	0%	0%	3%	200
Comparative
Example 3-3	95%	3%	0%	0%	3%	250
Comparative
Example 3-4	80%	0%	10%	Plaster10%		5%	100

The hardened products obtained in the above-mentioned Example 3 and Comparative Example 3 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 5.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness
	kg/cm²	kg/cm²			MPa • m^1/2
Example 3-1	330	850	Possible	None	3.3	7
Example 3-2	335	860	Possible	None	3.3	7
Example 3-3	340	865	Possible	None	3.3	7
Example 3-4	308	800	Possible	None	3.1	5.5
Example 3-5	310	800	Possible	None	3.1	5.5
Example 3-6	330	850	Possible	None	3.3	7
Example 3-7	310	800	Possible	None	3.3	5.0
Comparative
Example 3-1	290	850	Possible	None	3.0	4
Comparative
Example 3-2	290	850	Possible	None	3.0	4
Comparative
Example 3-3	270	750	Possible	None	2.8	4
Comparative
Example 3-4	270	750	Impossible	Observed	2.8	5

	Specific gravity
Example 3-1	1.2
Example 3-2	1.2
Example 3-3	1.2
Example 3-4	1.1
Example 3-5	1.1
Example 3-6	1.2
Example 3-4	1.1
Comparative
Example 3-1	1.0
Comparative
Example 3-2	1.0
Comparative
Example 3-3	1.0
Comparative
Example 3-4	1.0

(4) The following will describe Example 4, wherein the solid content in the ingredient solution was changed.

If the concentration thereof is below 3.5%, the solution is too dilute so that much time is required for ensuring a large thickness. Moreover, as time passes, the concentration drops so that uniformity in the thickness deteriorates. If it is over 25%, in-plane uniformity of the finished product deteriorates. Therefore, a warp is generated by drying.

The compositions of the solid contents in Example 4 and Comparative Example 4 are as follows.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Solid content
Example 4-1	95%	3%	0%	2%	4%
Example 4-2	90%	2%	5%	3%	5%
Example 4-3	98%	2%	0%	0%	10%
Example 4-4	80%	5%	15%	0%	15%
Example 4-5	70%	3%	20%	2%	5%
Example 4-6	95%	3%	0%	2%	25%
Example 4-7	65%	3%	30%	2%	25%
Comparative
Example 4-1	95%	3%	0%	2%	3%
Comparative
Example 4-2	95%	3%	0%	2%	30%
Comparative
Example 4-3	65%	3%	35%	2%	15%
Comparative
Example 4-4	80%	0%	10%	Plaster	10%	5%

The hardened products obtained in the above-mentioned Example 4 and Comparative Example 4 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 7. Concerning the amount of the warp, the maximum warp amount of the hardened products having a thickness of 1 m was measured.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness	Warp
	kg/cm²	kg/cm²			MPa • m^1/2		mm
Example4-1	330	850	Possible	None	3.3	7	2.2
Example4-2	335	860	Possible	None	3.3	7	2.0
Example4-3	340	865	Possible	None	3.3	7	4.0
Example4-4	308	800	Possible	None	3.1	5.5	3.6
Example4-5	310	800	Possible	None	3.1	5.5	2.0
Example4-6	330	850	Possible	None	3.3	7	4.0
Example4-7	310	800	Possible	None	3.3	5.0	4.0
Comparative
Example4-1	330	850	Possible	None	3.0	7	10.0
Comparative
Example4-2	330	850	Possible	None	3.0	7	12.0
Comparative
Example4-3	270	750	Possible	None	2.8	4	3.6
Comparative
Example4-4	270	750	Impossible	Observed	2.8	4	3.6

(5) The following will describe Example 5, wherein the speed of the carrying belt was changed.

Production conditions in Example 5 and Comparative Example 5 are as follows.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Speed m/s
Example 5-1	95%	3%	0%	2%	5
Example 5-2	90%	2%	5%	3%	10
Example 5-3	98%	0.1%	0%	1.9%	20
Example 5-4	80%	0.02%	15%	4.98%	30
Example 5-5	70%	3%	25%	2%	50
Example 5-6	90%	2%	0%	8%	60
Example 5-7	65%	5%	28%	2%	80
Comparative
Example 5-1	95%	0%	0%	5%	3
Comparative
Example 5-2	95%	0%	0%	5%	85

The hardened products obtained in the above-mentioned Example 5 and Comparative Example 5 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 9. Thickness scattering is represented by a percentage (%) obtained by dividing a plate having a size of 1 m square into 100 pieces, measuring the thickness thereof, calculating the average thereof and dividing a difference between the maximum value and the minimum value by the average.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness
	kg/cm²	kg/cm²			MPa • m^1/2
Example 5-1	330	850	Possible	None	3.3	7
Example 5-2	335	860	Possible	None	3.3	7
Example 5-3	340	865	Possible	None	3.3	7
Example 5-4	308	800	Possible	None	3.1	5.5
Example 5-5	310	800	Possible	None	3.1	5.5
Example 5-6	330	850	Possible	None	3.3	7
Example 5-7	310	800	Possible	None	3.3	5.0
Comparative
Example 5-1	330	850	Possible	None	3.0	7
Comparative
Example 5-2	330	850	Possible	None	3.0	7

	Thickness scattering %
Example 1	3%
Example 2	3%
Example 3	3%
Example 4	4%
Example 5	4%
Example 6	3%
Example 7	3%
Comparative
Example 1	7%
Comparative
Example 2	8%

(6) The following will describe Example 6, wherein the pressure in the press was changed.

The press is performed at 10-250 kg/cm². If the press is performed below 10 kg/cm², a required strength cannot be obtained. On the other hand, if the press is performed over 250 kg/cm², the strength cannot be made high so that the pressing device becomes large-sized and expensive. Furthermore, if the pressure is below 10 kg/cm², voids are generated so that the strength drops and an exfoliation or a warp is generated. On the other hand, if the pressure is over 250 kg/cm², the fibers are oriented in the direction along which the pressure is applied so that the strength drops and an exfoliation or a warp is generated in the same way. In any papermaking manner, originally fibers are easily oriented. Thus, a high pressure is inconvenient.

Production conditions in Example 6 and Comparative Example 6 are as follows. Five papermaking products are overlapped with each other, made reverse and laminated into a multilayer.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Pressure kg/cm²
Example 6-1	95%	3%	0%	2%	20
Example 6-2	90%	2%	5%	3%	30
Example 6-3	98%	0.1%	0%	1.9%	50
Example 6-4	80%	0.02%	15%	4.98%	60
Example 6-5	70%	3%	25%	2%	100
Example 6-6	90%	2%	0%	8%	150
Example 6-7	65%	5%	28%	2%	250
Comparative
Example 6-1	95%	0%	0%	5%	8
Comparative
Example 6-2	95%	0%	0%	5%	255

In Comparative Example 6-2, the papermaking products were not made into a multilayer, and the papermaking products of 20 mm were used.

The 20-mm thickness hardened products obtained in the above-mentioned Example 6 and Comparative Example 6 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 11. Concerning the methods of the test, the bending strength and the compressive strength were measured according to the methods prescribed in JIS A 6901 and JIS A 5416, respectively. Warp amount was measured about plates having a thickness of 20 mm and a size of 1 m square.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness
	kg/cm²	kg/cm²			MPa • m^1/2
Example 6-1	320	850	Possible	None	3.3	7
Example 6-2	335	860	Possible	None	3.3	7
Example 6-3	340	865	Possible	None	3.3	7
Example 6-4	308	800	Possible	None	3.1	5.5
Example 6-5	310	800	Possible	None	3.1	5.5
Example 6-6	330	850	Possible	None	3.3	7
Example 6-7	310	800	Possible	None	3.3	5.0
Comparative
Example 6-1	270	850	Possible	None	3.0	7
Comparative
Example 6-2	275	850	Possible	None	3.0	7

(7) The following will describe Example 7, wherein laminating was made with reversion, and Comparative Example 7, wherein papermaking products were laminated forward.

Production conditions in Example 7 and Comparative Example 7 are as follows. Five papermaking products were laminated into a multilayer.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Multilayer
Example 7-1	95%	3%	0%	2%	Reverse
Example 7-2	90%	2%	5%	3%	Reverse
Example 7-3	98%	0.1%	0%	1.9%	Reverse
Example 7-4	80%	0.02%	15%	4.98%	Reverse
Example 7-5	70%	3%	25%	2%	Reverse
Example 7-6	90%	2%	0%	8%	Reverse
Example 7-7	65%	5%	28%	2%	Reverse
Comparative
Example 7-1	95%	0%	0%	5%	Forward
Comparative
Example 7-2	95%	0%	0%	5%

In Comparative Example 7-2, the papermaking products were not made into a multilayer, and the papermaking products of 20 mm were used.

The 20-mm thickness hardened products obtained in the above-mentioned Example 7 and Comparative Example 7 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 13. Concerning warp amount, the maximum warp amount of the hardened products having a thickness of 20 mm and a size of 1 m square was measured.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness
	kg/cm²	kg/cm²			MPa • m^1/2
Example 7-1	330	850	Possible	None	3.3	7
Example 7-2	335	860	Possible	None	3.3	7
Example 7-3	340	865	Possible	None	3.3	7
Example 7-4	308	800	Possible	None	3.1	5.5
Example 7-5	310	800	Possible	None	3.1	5.5
Example 7-6	330	850	Possible	None	3.3	7
Example 7-7	310	800	Possible	None	3.3	5.0
Comparative
Example 7-1	330	850	Possible	None	3.0	7
Comparative
Example 7-2	330	850	Possible	None	3.0	7

	Warp mm	Exfoliation
Example 7-1	1.5	None
Example 7-2	1.5	None
Example 7-3	2.0	None
Example 7-4	1.8	None
Example 7-5	2.0	None
Example 7-6	2.0	None
Example 7-7	1.8	None
Comparative
Example 7-1	8.9	Observed
Comparative
Example 7-2	9.0	Observed

(8) The following will describe Example 8, wherein the amount of the flocculating agent was changed.

If the amount of the flocculating agent is below 0.01% by weight, no flocculating effect is caused. Thus, effects of warp-prevention and uniformity of the specific gravity and the strength are not produced. On the other hand, if it is over 5% by weight, the hardened product becomes ununiform by the flocculating agent so that a warp is generated or the gravity or the strength easily becomes ununiform.

The compositions of solid contents in Example 8 and Comparative Example 8 are as follows.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Solid content
Example 8-1	95%	3%	0%	2%	4%
Example 8-2	90%	2%	5%	3%	5%
Example 8-3	98%	0.1%	0%	1.9%	10%
Example 8-4	80%	0.02%	15%	4.98%	15%
Example 8-5	70%	3%	25%	2%	5%
Example 8-6	90%	2%	0%	8%	25%
Example 8-7	65%	5%	28%	2%	25%
Comparative
Example 8-1	95%	0%	0%	5%	5%
Comparative
Example 8-2	88%	12%	0%	0%	5%

The hardened products obtained in the above-mentioned Example 8 and Comparative Example 8 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. Concerning warp amount, the warp amount of plates having a size of 1 m square was measured. Scattering is represented by a percentage (%) obtained by dividing the plate having a size of 1 m square into 100 pieces, measuring the strength or the specific gravity thereof, calculating the average thereof and dividing a difference between the maximum value and the minimum value by the average.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness
	kg/cm²	kg/cm²			MPa • m^1/2
Example 8-1	330	850	Possible	None	3.3
Example 8-2	335	860	Possible	None	3.3
Example 8-3	340	865	Possible	None	3.3
Example 8-4	308	800	Possible	None	3.1
Example 8-5	310	800	Possible	None	3.1
Example 8-6	330	850	Possible	None	3.3
Example 8-7	310	800	Possible	None	3.3
Comparative
Example 8-1	330	850	Possible	None	3.0
Comparative
Example 8-2	330	850	Possible	None	3.0

	Brightness	Warp mm	Scattering in specific gravity %	Scattering in strength %
Example 8-1	7	2.0	3%	3%
Example 8-2	7	2.0	3%	3%
Example 8-3	7	2.0	3%	3%
Example 8-4	5.5	3.0	4%	4%
Example 8-5	5.5	3.0	4%	4%
Example 8-6	7	2.0	3%	3%
Example 8-7	5.0	3.0	3%	3%
Comparative
Example 8-1	7	10.0	7%	7%
Comparative
Example 8-2	7	10.0	8%	8%

(9) The following will describe Example 9, wherein the amount of the organic fibers was changed.

If the amount of the organic fibers is below 0.1% by weight, no reinforcing effect is produced so that break of the formed body cannot be prevented. On the other hand, if the amount is over 10% by weight, voids increases so that the water content rises. Thus, break is easily generated as well.

The compositions of solid contents in Example 9 and Comparative Example 9 are as follows.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Solid content
Example 9-1	95%	3%	0%	0.5%	4%
Example 9-2	90%	2%	5%	3%	5%
Example 9-3	98%	0%	0%	2%	10%
Example 9-4	80%	0%	15%	5%	15%
Example 9-5	70%	3%	20%	2%	5%
Example 9-6	90%	2%	0%	8%	25%
Example 9-7	65%	3%	30%	2%	25%
Comparative
Example 9-1	95%	3%	0%	0%	3%
Comparative
Example 9-2	95%	3%	0%	0.05%	20%
Comparative
Example 9-3	85%	3%	0%	12%	15%
Comparative
Example 9-4	95%	3%	0%	2%	85%
Comparative
Example 9-5	80%	0%	10%	Plaster	10%

Comparative Example 9-4 is based on a pressing process.

The hardened products obtained in the above-mentioned Example 9 and Comparative Example 9 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 2. Concerning formed bodies, each papermaking product before drying was cut into pieces having a size of 1 m square, and it was examined whether or not break of the piece was caused when it was raised up.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness	Fracture
	kg/cm²	kg/cm²			MPa • m^1/2
Example9-1	330	850	Possible	None	3.3	7	None
Example9-2	335	860	Possible	None	3.3	7	None
Example9-3	340	865	Possible	None	3.3	7	None
Example9-4	308	800	Possible	None	3.1	5.5	None
Example9-5	310	800	Possible	None	3.1	5.5	None
Example9-6	330	850	Possible	None	3.3	7	None
Example9-7	310	800	Possible	None	3.3	5.0	None
Comparative
Example9-1	330	850	Possible	None	3.0	7	Observed
Comparative
Example9-2	330	850	Possible	None	3.0	7	Observed
Comparative
Example9-3	270	750	Possible	None	2.8	4	Observed
Comparative
Example9-4	310	850	Possible	None	3.0	4	None
Comparative
Example9-5	270	750	Possible	None	2.8	4	Observed
Comparative
Example9-6	270	750	Impossible	Observed	2.8	5	Observed

(10) The following will describe Example 10, wherein the press was performed in a mold frame, and Comparative Example 10, wherein no mold frame was used. Production conditions in Example 10 and Comparative Example 10 are as follows.

	Papermaking sludge	Flocculating agent	Cement	Vinylon fiber	Solid content
Example 10-1	95%	3%	0%	2%	5%
Example 10-2	90%	2%	5%	3%	10%
Example 10-3	98%	0.1%	0%	1.9%	20%
Example 10-4	80%	0.02%	15%	4.98%	30%
Example 10-5	70%	3%	25%	2%	50%
Example 10-6	90%	2%	0%	8%	60%
Example 10-7	65%	5%	28%	2%	80%
Comparative
Example 10-1	95%	0%	0%	5%	3%
Comparative
Example 10-2	90%	0%	0%	5%	3%

Comparative Example 10-1 is based on press using no mold frame after a papermaking manner was performed.

The hardened products obtained in the above-mentioned Example 10 and Comparative Example 10 were tested about the bending strength, the compressive strength, the workability, the nailing property, the fracture toughness and the abrasion resistance thereof. The results are shown in Table 2.

	Bending strength	Compressive strength	Workability	Nailing property	Fracture toughness	Brightness	Tear
	kg/cm²	kg/cm²			MPa • m^1/2
Example10-1	330	850	Possible	None	3.3	7	None
Example10-2	335	860	Possible	None	3.3	7	None
Example 10-3	340	865	Possible	None	3.3	7	None
Example10-4	308	800	Possible	None	3.1	5.5	None
Example10-5	310	800	Possible	None	3.1	5.5	None
Example10-6	330	850	Possible	None	3.3	7	None
Example10-7	310	800	Possible	None	3.3	5.0	None
Comparative
Example10-1	330	850	Possible	None	3.0	7	Observed
Comparative
Example10-2	330	850	Possible	None	3.0	7	Observed

Next, referring to FIG. 14, the hardened product producing process and the hardened product producing machine according to a second embodiment of the present invention will be described.
The second embodiment is substantially equivalent to the first embodiment except the method of cutting a papermaking product and the direction along which the papermaking product is formed into a lamination. Therefore, explanation of others than the cutting method and the laminating direction is omitted.
In the above-mentioned first embodiment, the papermaking product 26 is cut into a size of 1 m × 2 m. On the other hand, in the second embodiment, the papermaking product 26 is cut into a size of 1 m × 1 m by the cutter 36. When the papermaking product 26 is put onto the reversing plate 46 in the reversing device 40 from the belt conveyor 38 by means of the carrying device 42, the papermaking product 26 is put after the papermaking product 26 is twisted at an angle of 90 degrees in the horizontal direction. In other words, when the papermaking product is formed into the lamination, the direction along which the papermaking product 26 is transferred from the wire cylinders 22A, 22B and 22C to the carrying belt 23 is shifted. In the papermaking product 26, strength difference is generated along the transferring direction to the carrying belt 23. Specifically, in the case that the strength when the papermaking product is bent along the transferring direction is made to 1, the strength perpendicular to the transferring direction is about 0.8. In the second embodiment, a hardened product having a uniform strength is produced by forming the papermaking product 26 into the lamination in such a manner that the transferring direction to the carrying belt 23 is shifted when the papermaking product is formed into the lamination.
The following will describe a composite construction material as one application example of the composite hardened product 1.
That is, as illustrated in FIG. 19, in a composite construction material wherein a reinforcing layer 6 or reinforcing layers 6 is/are formed on at least one face of a core material 5, particularly on both faces thereof in the illustrated example, the composite hardened product 1 produced by this invention is applied to the core material 5. That is, by making the core 5 up to the composite hardened product 1 produced by this invention, destruction is not easily caused even if tensile power is applied to this core material. This is because the core material itself is superior in bending strength and additionally the reinforcing layer(s) is/are deposited on the surface(s) of the core material. Even if pressure is locally applied to the surface, no concave or hollow is generated.
Furthermore, when this composite construction material is used, a decorative layer based on coating, a decorative laminated sheet or a decorative mono-sheet is deposited on the reinforcing layer 6. Therefore, the impact resistance thereof is improved so that injuries such as concaves are not easily generated. Thus, it does not happen that the decorative face is distorted by the injuries so that the aesthetic property thereof deteriorates.
The reinforcing layer 6 has a structure wherein a fiber substrate 6b is embedded in a resin 6a. It is particularly desirable to use a thermosetting resin as this resin 6a. This is because no function as the reinforcing layer is lost since the thermosetting resin, which is different from a thermoplastic resin, is superior in fire resistance so that it does not soften even at high temperature. As the thermosetting resin, suitable are phenol resin, melamine resin, epoxy resin, polyimide resin, urea resin and so on. In order to give sufficient rigidity, impact resistance and higher fire resistance to the reinforcing layer, it is desirable that the content of the thermosetting resin in the reinforcing layer ranges from 10 to 65% by weight.
It is desirable to use an inorganic fiber for the fiber substrate 6b. This is because the inorganic fiber makes it possible to improve the strength of the reinforcing layer 6 and make the thermal expansion coefficient thereof small. From the viewpoint of low costs, superior fire resistance and superior strength, it is preferred to use, as the inorganic fiber, at least one of glass fiber, rock wool, ceramic fiber, a glass fiber chopped strand mat, glass fiber roving cloth, a glass fiber continuous strand mat, and glass fiber paper. It is possible to use, as this fiber substrate, discontinuous fibers formed into a mat, a product obtained by cutting continuous long fibers into a size of 3 to 7 cm and then making the cut fibers into a mat form (the so―called chopped strand mat), a product obtained by dispersing fibers into water and making the resultant solution into a sheet, a product obtained by forming continuous long fibers into a lamination and making the lamination into a mat form, or a product obtained by weaving continuous long fibers.
The thickness of the reinforcing layer is desirably from 0.1 to 3.5 mm. If the thickness is set within this range, sufficient rigidity and impact resistance can be obtained and high workability can be kept. It is allowable to add, to the reinforcing layer, a fire retardant such as aluminum hydroxide or magnesium hydroxide, or an inorganic binder which is generally used, such as silica gel, alumina sol or water glass. The reinforcing layer is deposited herein, but the surface may be coated with a resin or the like in order that the hardened product may not absorb water content.

Claims

A papermaking sludge hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge and comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca,
characterized in that the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and
the brightness of the hardened product is N5 or more as the value based on the regulation of JIS Z 8721.
A papermaking sludge hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge and comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca,
wherein the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively.
The papermaking sludge hardened product according to claim 1, wherein the crystal habit of the calcium carbonate is at least one form selected from spindle, horn, thin table, cubic or columnar forms.
The papermaking sludge hardened product according to any one of claims 1-3, wherein the content of cement in the papermaking sludge is 0 or 30% or less by weight.
A papermaking sludge hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge and comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca,
wherein the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and a flocculating agent is contained.
A papermaking sludge hardened product which is obtained by subjecting papermaking sludge to a papermaking manner and hardening the sludge and comprises an organic fibrous material made of a polysaccharide and calcium carbonate in an inorganic amorphous material made of oxides of Si, Al and Ca,
wherein the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and synthetic fibers are contained.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a rotary drum rotating at 1 to 100 times/minute to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the rotary drum, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a drainage body having a mesh structure of #40 to 150 to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a rotary drum composed of a netlike body to subject an ingredient solution containing papermaking sludge and having a solid content concentration of 3.5 to 25% by weight to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the netlike rotary drum, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt having a speed of 5 to 80 m/minute, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a rotary drum composed of a netlike body to subject, to a papermaking manner, an ingredient solution containing papermaking sludge in which the amounts of Ca, Al and Si, the amounts being converted into the amounts of CaO, Al₂O₃ and SiO₂, are adjusted in the manner that the ratio of CaO/SiO₂ and the ratio of CaO/Al₂O₃ are from 0.2 to 7.9 and from 0.2 to 12.5, respectively, and adhering a papermaking product of the papermaking sludge to a surface of the rotary drum, and further transferring this papermaking product onto a carrying belt of a porous body having continuous pores, dehydrating the papermaking product while carrying the papermaking product on the carrying belt, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product onto a cutting rotary drum, cutting the papermaking product into a given size when the multilayered papermaking product turns into a given thickness, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner, laminating resultant papermaking products of the papermaking sludge, and pressing the laminated papermaking products at a pressure of 10 to 250 kg/cm².
A process for producing a hardened product by laminating papermaking products of papermaking sludge obtained by subjecting an ingredient solution containing the papermaking sludge to a papermaking manner, and then hardening the papermaking products,
characterized in that the papermaking products are alternately made reverse and laminated when the papermaking products are laminated.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product onto a cutting rotary drum, cutting the papermaking product into a given size, and laminating and hardening resultant papermaking products,
characterized in that the papermaking products are alternately made reverse and laminated when the papermaking products are laminated.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, transporting the papermaking product, forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product onto a cutting rotary drum, cutting the papermaking product into a given size, and laminating and hardening the resultant papermaking products to obtain the hardened product of the papermaking sludge,
characterized in that when the papermaking products are laminated, naked faces of the papermaking products of the topmost layer and the lowermost layer are made to faces contacting the rotary drum, and laminating faces of the papermaking products are laminated while they are alternately made reverse.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product onto a carrying belt, cutting the papermaking product into a given size, and laminating and hardening the resultant papermaking products,
characterized in that when the papermaking products are laminated, the papermaking products are laminated in the manner that the transferring direction thereof to the carrying belt is shifted.
A process for producing a hardened product, characterized by adding a flocculating agent to an ingredient solution containing papermaking sludge to flocculate the solution, using a drainage body to subject this flocculated ingredient solution to a papermaking manner, and hardening this papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by adding a flocculating agent to an ingredient solution containing papermaking sludge to flocculate the solution, using a drainage body to subject this flocculated ingredient solution to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product to a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by adding a binder to an ingredient solution containing papermaking sludge, using a drainage body to subject this ingredient solution to a papermaking manner, and hardening this papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by adding a binder to an ingredient solution containing papermaking sludge, using a drainage body to subject this ingredient solution to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, and further transferring this papermaking product to a carrying belt, transporting the papermaking product, cutting the papermaking product into a given size, and hardening the papermaking product to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner, and pressing a resultant papermaking product of the papermaking sludge in a mold frame to obtain the hardened product of the papermaking sludge.
A process for producing a hardened product, characterized by using a drainage body to subject an ingredient solution containing papermaking sludge to a papermaking manner, laminating resultant papermaking products of the papermaking sludge, and pressing the laminated papermaking products to produce the hardened product of the papermaking sludge.
The process for producing the hardened product according to any one of claims 7-24, characterized in that the concentration of solid content in the ingredient solution containing the papermaking sludge is from 3.5 to 25% by weight.
The process for producing the hardened product according to any one of claims 7-11, 13, and 19-22, characterized in that the papermaking product is dehydrated while the papermaking product is carried on the carrying belt.
The process for producing the hardened product according to any one of claims 7-12, characterized in that the papermaking product on the carrying belt is formed into a multilayer while the papermaking product is transferred to a cutting rotary drum, and the multilayered papermaking product is cut when it turns into a given thickness.
The process for producing the hardened product according to any one of claims 7-13 and 15-22, characterized in that the cut papermaking product is further formed into a multilayer and subsequently the multilayered papermaking product is pressed.
The process for producing the hardened product according to any one of claims 23, 24 and 28, characterized in that the press is performed at a pressure of 10 to 250 kg/cm².
The process for producing the hardened product according to claim 10, wherein the ingredient solution contains no cement, or contains cement whose solid content is 30% or more by weight.
The process for producing the hardened product according to any one of claims 14-18 and 23, characterized in that the papermaking products are laminated in the manner that the ingredient solution is interposed therebetween.
The process for producing the hardened product according to any one of claims 14-18 and 24, characterized in that the papermaking product is formed to have a thickness of 20 mm or less.
The process for producing the hardened product according to claim 19 or 20, characterized in that the flocculating agent is any one of aluminum sulfate, ferric chloride, polyaluminum chloride, polysodium acrylate, ester of polymethacrylic acid, ester of polyacrylic acid, and polyacrylamide.
The process for producing the hardened product according to claim 21 or 22, characterized in that the binder is an organic fiber.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge.
A machine for producing a hardened product, characterized by comprising:

a rotary drum for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drum, the rotation speed thereof being from 1 to 100 times/minute,

a carrying belt for transferring the papermaking product adhered to the surface of the rotary drum and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body, the drainage body having a mesh structure of #40 to 150,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge.
A machine for producing a hardened product, characterized by comprising:

a rotary drum, which is composed of a netlike body, for subjecting an ingredient solution containing papermaking sludge and having a solid content concentration of 3.5 to 25% by weight to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drum,

a carrying belt for transferring the papermaking product adhered to the surface of the netlike rotary drum and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product, the carrying speed thereof being from 5 to 80 m/minute,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge.
A machine for producing a hardened product, characterized by comprising:

a rotary drum, which is composed of a netlike body, for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drum,

a porous carrying belt for transferring the papermaking product adhered to the surface of the rotary drum, and dehydrating the papermaking product while carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product,

a cutting rotary drum for forming the papermaking product on the carrying belt into a multilayer while transferring the papermaking product, the cutting rotary drum comprising a groove wherein water is accommodated in its surface and a pushing-out mechanism, positioned near this groove, for pushing out the papermaking product from its inside,

wherein the pushing-out mechanism is operated when the papermaking product whose surface is multilayered turns into a given thickness, thereby cutting the papermaking product at a position corresponding to the groove, and
a hardening device for hardening the cut papermaking product to obtain the hardened product of the papermaking sludge.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a laminating device for laminating the cut papermaking products of the papermaking sludge so that the ingredient solution is interposed therebetween.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a laminating device for making the cut papermaking products of the papermaking sludge reverse alternately and laminating the papermaking products.
A machine for producing a hardened product, characterized by comprising:

a papermaking device for subjecting an ingredient solution containing papermaking sludge to a papermaking manner to produce a papermaking product of the papermaking sludge, and

a pressing device for putting the papermaking product of the papermaking sludge into a mold frame and then pressing the papermaking product, the pressing device comprising a hole for releasing water content exuding from the papermaking product.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size, and

a pressing device for putting the papermaking product of the papermaking sludge into a mold frame and then pressing the papermaking product, the pressing device comprising a hole for releasing water content exuding from the papermaking product.
A machine for producing a hardened product, characterized by comprising:

a drainage body for subjecting an ingredient solution containing papermaking sludge to a papermaking manner and adhering a papermaking product of the papermaking sludge to a surface of the drainage body,

a carrying belt for transferring the papermaking product adhered to the surface of the drainage body and carrying the papermaking product,

a cutting device for cutting the papermaking product carried on the carrying belt into a given size,

a laminating device for laminating the cut papermaking products of the papermaking sludge so that the ingredient solution is interposed therebetween, and

a pressing device for putting the papermaking product of the papermaking sludge into a mold frame and then pressing the papermaking product, the pressing device comprising a hole for releasing water content exuding from the papermaking product.
The machine for producing the hardened product according to any one of claims 35-37 and 39-42, characterized in that the drainage body is a rotary drum composed of a netlike body.
The machine for producing the hardened product according to any one of claims 35 and 37-43, characterized in that the rotation speed of the rotary drum is from 1 to 100 times/minute.
The machine for producing the hardened product according to any one of claims 35-42, characterized in that a plurality of the drainage bodies are arranged along the carrying belt and the papermaking product is transferred onto the carrying belt while the papermaking product is formed into a multilayer.
The machine for producing the hardened product according to any one of claims 35, 36 and 38-42, characterized in that the drainage body has a mesh structure of #40 to 150.
The machine for producing the hardened product according to any one of claims 35-38 and 41, characterized in that the carrying speed of the carrying belt is from 5 to 80 m/minute.
The machine for producing the hardened product according to any one of claims 35-39 and 41, characterized in that the carrying belt is composed of a porous body having continuous pores.
The machine for producing the hardened product according to any one of claims 35-40, characterized in that the cutting device is composed of a cutting rotary drum for making the papermaking product into a multilayer while transferring the papermaking product,
the cutting rotary drum comprising a groove in which water is accommodated in the surface thereof, and a pushing-out mechanism, positioned near this groove, for pushing out the papermaking product from its inside, and
the pushing-out mechanism is operated when the multilayered papermaking product on the surface of the cutting rotary drum turns into a given thickness, thereby cutting the papermaking product at a position corresponding to the groove.
The machine for producing the hardened product according to claim 53, characterized in that the cutting device further comprises a blade for cutting, at regular intervals, the papermaking product whose end is cut by the cutting rotary drum.
The machine for producing the hardened product according to claim 41, characterized by comprising a blade for cutting, at regular intervals, the papermaking product whose end is cut by the cutting rotary drum.
The machine for producing the hardened product according to claim 43, characterized in that the laminating device causes the papermaking products of the papermaking sludge to be laminated so that the ingredient solution are interposed therebetween.