JPH0213520Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to single-layer fiberboard obtained from paperboard manufacturing waste, which has traditionally been disposed of in landfills. Fibreboard according to the Japanese Standard (JIS) refers to a board made from vegetable fibers such as waste wood chips, bagasse, pulp shavings, and sawdust as main raw materials. Hard fiberboard is the best in terms of mechanical strength and water resistance. It is excellent. Therefore, although hard fiberboard has a wide range of uses such as building materials and packaging materials, it is quite expensive, so it is hoped that it will become cheaper. Apart from this problem, paperboard manufacturing plants mainly use a mixture of kraft pulp and waste paper as paperboard raw materials, which generates various wastes during the paperboard manufacturing process. For example, a large amount of knots (cooking) residue is generated during the production of kraft pulp, while pulper residue is generated when waste paper or pulp is disintegrated, and even after the disintegrated waste paper is blended with an appropriate paper stock, various screen residues and cleaners are generated. Dregs and terminal sludge are produced. Of these wastes, some of the knot and cleaner residues are used as raw materials for low-grade paper, the final sludge is recycled, and chipper dust is used as fuel for boilers, but most of them are used economically and effectively. Currently, there is no way to dispose of it, and it is difficult to dispose of it since it is generated in large quantities. In particular, waste such as pulper residue generated when disintegrating used paperboard includes gummed tape, vinyl tape, vinyl acetate adhesives, plastic film, staples, dirt, etc. that adhered to paper cartons and paper bags. There is no suitable disposal method other than landfilling, which is expensive and has been blamed for being a source of pollution. This invention was proposed in order to simultaneously solve the above-mentioned cost problems associated with conventional hard fiberboards and the problem of disposing of paper manufacturing waste discharged in large quantities from paper mills. It is therefore an object of this invention to provide an inexpensive single-layer fiberboard manufactured by advantageously processing large amounts of paper manufacturing waste. When manufacturing the single-layer fiberboard 1 as illustrated in FIG. 1, the raw material is paper manufacturing waste, and because it drains easily, waste from paperboard factories is mainly used.
The waste cannot be recycled or is considerably uneconomical to reuse by re-selection or recovery. Examples of this type of waste include pulper sludge, Jansson sludge, flat screen sludge, centric cleaner sludge, terminal sludge, and Japanese paper terminal sludge, etc., used alone or in combination of two or more to control the quality of the fiberboard obtained. For this purpose, knot dregs, adjusted sludge, etc. may be added. Pulper sludge, various types of screen sludge, and cleaner sludge include fibrous byproducts separated from waste paper and pulp, as well as duct tape, vinyl tape, vinyl acetate adhesive, plastic film, staples, earth and sand, etc. All but a portion of it can be used for manufacturing fiberboard. The single-layer fiberboard 1 according to this invention is made of about 20 small pieces of gummed tape, vinyl tape, vinyl acetate adhesive, plastic film, etc. contained in paper manufacturing waste.
Although ~30% by weight remains, most of these are melted during the high-temperature heating and pressurizing process, forming the fused material A.
This serves to increase the mechanical strength of the fiberboard 1. This fiberboard 1 includes various fibrous solids B
It has properties similar to those of kraft paper as a main component, so it has excellent heat retention and sound insulation properties, and the presence of a waterproofing agent also makes it excellent in water resistance and moisture resistance. Furthermore, this fiberboard 1 is heated to 100°C.
No change in shape occurs even after boiling in boiling water for 2 hours.
It can be cut with a saw and has excellent nail holding power.
Even when surface painting is performed, the decorative paint spreads well and does not peel off. This fiberboard 1 is a single layer with a thickness of 2~
It can be made up to 15mm and has a quality equivalent to that of hard fiberboard specified in JIS A5907, and its bending strength can be greatly increased by special treatment with oil, resin, etc. However, in applications where the bending strength does not need to be very high, approximately
Can be formed up to a thickness of 50mm or less. Next, the manufacturing process of the fiberboard 1 of this invention will be explained with reference to FIG. Pulper dregs, various screen dregs, and cleaner dregs, which have a high solid content among paper manufacturing wastes, are first put into the crushing tank 2 and crushed into small pieces ( For example, the material is crushed into pieces with a length of approximately 5 mm or less. In the crushing tank 2, the contents are stirred and circulated by one or two wet crushers (for example, Sluzer Pump, trade name, manufactured by Komatsu Zenoah Co., Ltd.). From the bottom 4 of the crushing tank 2, metal pieces such as staples that cannot be crushed and earth and sand are removed. The crushed contents generally pass through a transfer pump (not shown) to a cyclone 5.
Here, remaining metal pieces, earth and sand are completely removed, and the water is then fed from the cyclone to a mixing tank 6 via a screen or roller dehydrator (not shown) as desired. Chip-shaped knot dregs, various types of sludge, etc. that do not require crushing may be directly charged into the mixing tank 6 as desired. In the mixing tank 6, the concentration measuring device 7 measures the concentration of the aqueous waste liquid at approximately 2
-4% by weight to increase the fluidity of the aqueous waste liquid, and add a binder, a water resistance agent, etc. from the chemical tank 8 and stir vigorously. As an example, the binder may be a thermosetting phenolic resin (for example, the trade name SK agent,
(manufactured by Dainippon Ink & Chemicals Co., Ltd.) and the water resistant agent is a paraffin emulsion (for example, the product name WR+N
liquid, manufactured by Dainippon Ink and Chemicals Co., Ltd.). The amount of thermosetting phenolic resin added is approximately 2 to 8 parts by weight per 100 parts by weight of the aqueous waste liquid. Generally speaking, the larger the amount added, the higher the mechanical strength of the fiberboard. If it exceeds a certain amount, the mechanical strength will not increase, and if it is less than a certain amount, it cannot be used as a hard fiberboard. On the other hand, the amount of water resistance agent added is about 1 to 3 parts by weight per 100 parts by weight of the absolute dry amount of aqueous waste liquid,
A value within this range is effective for maintaining a predetermined water resistance of the fiberboard. In this case, the pH value of the aqueous waste liquid is adjusted to 4.5 to 5.0 by adding an appropriate amount of sulfuric acid to fix the binder and waterproofing agent.
If desired, paint or the like may be added from the chemical tank 8. The aqueous waste liquid thus obtained is a sol-like substance using water as a dispersion medium, and is sent to the raw material tank 9 via, for example, a centrifugal pump (not shown). Stirring is performed in the raw material tank 9, and then the aqueous waste liquid is quantitatively charged into the primary molding machine 10 via a measuring tank (not shown) as desired. The primary molding machine 10 has a structure as illustrated in FIG. In the primary forming machine 10, the upper press plate 11 has a front wall 12 with a large number of through grooves 13, and a wire mesh 14 is stretched over the surface of the front wall. The pressure plate 11 squeezes water in the direction of arrow V by a vacuum pump (not shown). Also, the front wall 1 of the receiving plate 15
6 are also provided with a large number of through grooves 17, a wire mesh 18 is stretched over the surface of the front wall, and a formwork 19 with an inner diameter approximately equal to the outer diameter of the pressure plate 11 is placed on the receiving plate 15, and the through grooves are The liquid falling from 17 is discharged in the direction of arrow F. The aqueous waste liquid enters the formwork 19 from the inlet 20 as indicated by arrow L. The aqueous waste liquid 21 in the formwork 19 is squeezed in two stages, and in the first stage, the pressure platen 11 is moved in the direction of arrow D to dehydrate it, for example, at a surface pressure of about 5 to 10 kg/cm ² . Then, in the second step, using a flat pressure plate (not shown), the mold 19 is removed, and water is dehydrated under high pressure of about 10 to 30 kg/cm ² to form a flat plate. As a result, the moisture content of the obtained primary formed plate is approximately 50% or less, preferably 40 to 45%.
The thickness is about 40-45% of the inflow.
The liquid discharged from the primary molding machine 10 is sent to a liquid tank 22 (FIG. 2), from which it is returned to the mixing tank 6 via a transfer pump (not shown), and a portion thereof is discharged as waste water. Also, primary molding machine 1
The washing water used in step 0 is sent to the overtank 23 and returned from the overtank to the crushing tank 2 via a transfer pump (not shown). Since the primary molded plate still has a high moisture content, it needs to be subjected to moisture evaporation treatment, and for this purpose it is passed through a heating furnace 24. This moisture evaporation method may be carried out by heating to 200 to 250°C using a dark infrared device (for example, Infrastein, manufactured by Nippon Insulators), or by heating with hot air using a steam heat source. , dark infrared equipment is superior in terms of production efficiency and equipment space. After passing through the heating furnace 24,
The moisture content of the primary formed plate is reduced to about 22-25%. The primary molded plate after the moisture evaporation treatment is further secondary molded to a specified thickness by a secondary molding machine 25. As the secondary forming machine 25, for example, a known hot multistage press is used, and the temperature of the hot plate of the press is
Adjust the temperature to around 170-180℃ and the surface pressure to about 20-30Kg/ ^cm2 . Due to secondary forming, the moisture content of the fiberboard is approximately
It will be less than 10%. The edges of the obtained single-layer fiberboard are sequentially cut using a slitter 26, loaded on an auto stocker 27, and stored in a warehouse. It can be stored in a warehouse for 10 to 15 days, and then shipped after adjusting the humidity appropriately. The single-layer fiberboard according to this invention is inexpensive because it uses paper manufacturing waste, which cannot be reused or is considerably uneconomical to recycle, as a raw material, and can save resources and contribute to the prevention of pollution. The fiberboard of this invention can be made into a single layer with a thickness of 2 to 15 mm, so it can be used as is for various purposes, and when it is made into a laminated material, the manufacturing process becomes complicated, which increases costs and reduces the peel strength of the board. can be avoided. Applications for this fiberboard include wall materials for prefabricated houses and wooden houses, insulation materials, flooring materials, architectural panels such as ceiling panels, boards for concrete formwork, core material for furniture and fittings, and interior decoration for automobiles, ships, and vehicles. Examples include materials, parts for electrical equipment, etc. In addition, for applications that are mainly subject to pressure resistance, such as pallet girders, the bending strength does not need to be very high, so a single layer can have a
It can be formed up to a thickness of mm or less. Example 1 To experimentally manufacture a fiberboard with a thickness of 2.5 mm,
5 kg of pulper dregs (absolutely dry weight, the same applies hereinafter) generated in the paperboard manufacturing process and 5 kg of Janson screen are used. These are put into a crushing tank containing 340 ml of water.
When crushed for about 10 minutes using a crusher (trade name: Suluzer Pump), it becomes small pieces about 5 mm in length. This aqueous waste liquid was placed in a mixing tank, and 5% by weight of the absolute dry amount of thermosetting phenolic resin (product name: SK agent) was added thereto, stirred for 10 minutes, and then paraffin-based emulsion (product name: WR+N liquid) was added. After stirring for 5 minutes, 3% by weight of sulfuric acid salt was added and stirred. The obtained aqueous waste liquid 68 was fed into the formwork (width 975 x length 975 x height 200 mm) of a pressure press, which is a primary molding machine, and the surface pressure was 5 kg/cm2 for about 25 seconds, and then the surface pressure was 15 kg/ ^cm2 . ^cm2
Pressurize for about 25 seconds. The obtained primary formed plate has a thickness of
It is 3.9mm, weighs 3.7Kg, and has a moisture content of 45%. This primary molded plate is passed through a heating furnace of a dark infrared device (trade name: Infrastein) to evaporate 1.1% of the moisture using 1KW/min of electricity. Next, secondary molding is performed, and the hot press of the secondary molding machine uses a steam heat source, a hot plate temperature of 180°C, and heat presses for about 2 minutes at a surface pressure of 20 kg/cm ² . The final product has a moisture content of around 8%, and its dimensions are width 975 x height 975 x thickness 2.5 ± 0.5
mm. The physical properties of this fiberboard were measured according to JIS A5905-5907 and are as follows.

[Table] For hard fiberboard S200 specified in JIS A5907, the criteria are specific gravity of 0.8 or more, moisture content of 5 to 13%, and bending strength.
The fiberboard of this example passed all of the standards, with a water absorption rate of 200 kg/cm ² or more and a water absorption rate of 30% or less. Example 2 To experimentally manufacture a fiberboard with a thickness of 12 mm,
Using the same manufacturing equipment as in Example 1, and in Example 1
The aqueous waste liquid obtained in step 300 is sent into the formwork of a pressure press. With a pressure press, press with a surface pressure of 10 kg/cm ² for about 30 seconds, then press with a surface pressure of 20 kg/cm ² for about 30 seconds, and the thickness
The primary formed plate is 16 mm long, weighs 15 kg, and has a moisture content of 45%. This primary formed plate is passed through a heating furnace to reduce moisture content.
is evaporated at an electricity consumption of 4.5 KW/min, and then heated and pressed using a hot press at a surface pressure of 20 Kg/cm ² for about 10 minutes, resulting in a final product with a moisture content of around 8%. The obtained fiberboard passes all the standards of JIS A5907. Example 3 In order to produce 100,000 sheets of fiberboard with a thickness of 3 mm per month, 70 tons of pulper sludge (absolute dry weight, the same applies hereinafter), 75 tons of knot sludge, 240 tons of final sludge, and 18 tons of adjusted sludge are used per month. . Only the pulper residue is crushed in advance in a crushing tank at a rate of 1 m ³ /min. 760 kg/hour of these raw materials are put into a mixing tank with an actual volume of 22 m ³ , and from the chemical tank thermosetting phenolic resin (product name: SK agent) (monthly usage amount: 20 tons) is then mixed with paraffin emulsion (product name: WR+N liquid). (monthly usage amount: 10 tons) and further add sulfuric acid chloride to adjust the pH of the aqueous waste liquid to 4.5 to 5.0. The water content of the aqueous waste liquid obtained is 96.5%. This aqueous waste liquid is
The material is sent to a raw material tank with an actual volume of 22 m ³ and stirred, and then weighed out in a measuring tank to yield 113 kg per sheet. The primary forming machine is a hydraulic press type double wire and high pressure press (1st stage output: 120 tons,
2nd stage output 350 tons) (manufactured by Yamamoto Iron Works),
The shape of the formwork is 920 mm wide x 1830 mm long x 68 mm high.
The water content of the aqueous waste liquid is 60 at the surface pressure of 7Kg/ ^cm2 in the first stage.
%, and the moisture content is 45 at a surface pressure of 20 Kg/ ^cm2 in the second stage.
%. The obtained primary formed plate weighs 10 kg/sheet,
The thickness is 4.4 mm, and the production efficiency is 4 to 10 m/min. This primary formed plate undergoes moisture evaporation treatment in a heating furnace using a 350KW dark infrared device (trade name Infrastein), and the amount of electricity used in the furnace is
It has a processing capacity of 260KW/hour and a processing capacity of 190 sheets/hour. With this heating furnace, the amount of moisture evaporated from the primary formed plate is 1.5
/ sheet, and its thickness is 4.0 mm. As a secondary forming machine, the output is 350 tons and the number of stages is 10.
Using a hot multi-stage press (manufactured by Yamamoto Iron Works), a surface pressure of 20 kg/cm ² and a hot plate temperature of 170°C were used for 20 cycles.
After secondary forming at a rate of 930 mm x 184 mm x 3 mm thick. Next, use a suritsuta to cut the edges at a speed of 8 seconds/sheet, and cut the edges to a width of 910mm x height of 1820mm x thickness of 3mm.
of fiberboard. This fiberboard will be loaded into an auto stocker with a capacity of 420 sheets and stored in a warehouse. The obtained fiberboard passes all the standards of JIS A5907.

[Brief explanation of the drawing]

Figure 1 is a perspective view illustrating the single-layer fiberboard according to this invention, Figure 2 is a flow sheet illustrating the manufacturing process of the single-layer fiberboard, and Figure 3 is the primary forming used in the manufacturing process of Figure 2. FIG. 2 is a schematic cross-sectional view showing the main parts of the machine. 1...Single layer fiberboard, A...fused material, B...fibrous solid material.

Claims (1)

[Scope of utility model registration request] It is a flat plate mainly made from pulper sludge, screen sludge, cleaner sludge, terminal sludge, etc. produced when disintegrating used paperboard and waste paper, and consists of fibrous solids crushed into small pieces, gummed tape, It consists of small pieces of plastic such as vinyl tape, adhesive, and film, and further contains a thermosetting phenolic resin and a water-resistant agent as a binder.
0.8 or more, bending strength 200Kg/cm ² or more, and thickness 2 to 15
A single-layer fiberboard characterized by being made of mm hard fiberboard.