DE1104419B - Method and device for the production of building structures - Google Patents

Description

Method and device for the production of building structures The invention initially refers to a process for the production of structures from fibrous materials. or the like are more prone to mechanical bonding of individual particles. Fabrics or from substances with added fibers and mineral sulphatic binders.

There are methods for the production of structures, such. B. Plates, from Fibers and hydraulic binders, such as cement, known for which continuous an aqueous slurry of fiber and cement made, distributed, shaped and pressed, on a moving endless suction pad. The excess water is removed from the fiber cement mass by suction. It is also known that the fiber cement nonwoven formed by means of a to press together the rotating roller, which may be in the plane of the fleece. and is moved.

It is also known that the endless substrate a15 is water-permeable Tape, e.g. B. as a cotton belt, but also as a metallic screen belt and to arrange vacuum suction heads under this band. Next it is known to have the tape Tapping and cleaning by rinsing with water and the squeezed and other Run excess water back into a mixer for the preparation of further cheeses allow.

With non-hydraulic binders, e.g. B. plaster, settled in this Way so far not working. Plaster of paris structures have so far mostly been made in molds. There are z. B. standardized gypsum blocks. We also know plasterboards and plasterboards and wall cladding panels made from plaster of paris with suitable aggregates and fillers are made and differ from the wall panels mainly only by their Dimensions differ. Sound-absorbing panels made of high-quality plaster are also Filling plates, heating plates and similar structures are known. Finally there is too Gypsum cardboard panels.

In the known production of gypsum structures in forms, the Plaster of paris in a more or less liquid state poured into the wooden or metal molds. After the mass has hardened, the mold is removed and the resulting plaster structure natural or artificially dried. It is also already known to be used in the manufacture to operate gypsum structures in the form of mechanical aids.

Used in the known production of gypsum structures in molds one plaster of paris. You had to keep the addition of water as low as possible in order to be sufficient To achieve strength, because less resistant with a larger excess of water Crystals and larger pores are created. The strength is then sufficient, not the loads which occur particularly when transporting the plaster of paris structures. The ratio of water weight The weight of plaster of paris was around 0.75 for usable mixtures. Even with one of these The ratio of the paste already contains 3 to 4 times that theoretically required for setting the plaster of paris necessary amount of water to be formed as crystal water.

Such gypsum paste has already been found on roller lines for gypsum cardboard processed. In doing so, the plaster of paris is left in the shallow cavity Pour in high-quality cardboard. The cardboard used as the mold remains with the plaster core firmly connected and gives it its elasticity. Another way to mass-produce thin elastic structures using plaster of paris did not exist up to now.

The invention consists first of all in the fact that the said fiber or fibrous materials and gypsum or gypsum slag cements as binders a slurry (suspension) with a large excess of water and the addition of retarders manufactured, preformed into a fleece and the main part of the water before entry the setting process is removed.

One possible implementation is as mineral, sulphatic Binders air binders, e.g. B. plaster of paris, to use another in it, besides Air binders a hydraulic sulphatic binder, namely gypsum slag cement, to use.

"Air binders" are to be understood as meaning those that are listed under Water does not harden, under "hydraulic binders" those that are also under Harden water.

One of the difficulties faced by the continuous manufacture of Gypsum fiber boards in continuous processes failed so far, is that the excess water acting as crystallization nuclei, set Plaster parts which do not allow you to use this water again because these germs The setting of gypsum paste, to which they are added with this water, greatly accelerate the setting.

Hemihydrate is more soluble in water than dihydrate. Based on this the setting of the plaster of paris. The Hall) hydrate goes into the dihydrate in the dissolved state over, of which only a smaller part can remain dissolved than before as hemihydrate was dissolved, so that the excess must precipitate in the solid state. There with it again If water is available in order to be able to dissolve hemihydrate, the process can continue.

A sub-task on which the further development of the invention is based consisted in the acceleration of the setting "of the plaster of paris with iseal-containing water to dominate.

-: after what has been explained above, one possible way of doing this was to reduce the solubility of the hemihydrate and a second way to reduce the solubility of the hemihydrate. Various substances that can form precipitates with gypsum reduce the solubility and dissolution rate of the hemihydrate, so that the setting process can be delayed by adding such substances. Such substances are z. B. ammonium carbonate, sodium phosphate, tannin, keratin, etc. The effect of these substances may result from the fact that they cover the individual gypsum grains with a layer of precipitate; the denser and more impermeable this skin is, the more the rate of dissolution will be reduced. I found keratin to be particularly effective. The solubility of the hemihydrate in water drops from 0.885 to 0.678 g1100 when 2% keratin is added, and the rate of dissolution is reduced so much that the setting process is extended from 32 minutes to 8 days.

The further development of the invention is also based on the knowledge that the setting accelerating effect of the gypsum germs in the water when used of retarders only increases until a maximum value is reached, that is, a state of equilibrium occurs, after which an increase in hardened gypsum parts in the water the setting of the plaster of paris no longer accelerates.

The amounts of plaster of paris going into solution are usually very large. she amount to about 15% of the gypsum requirement when the separated water is not used remains, mean a considerable loss of material and also through crystallization cause malfunctions in unsuitable places. If, on the other hand, the separated Water reused, then accelerate the precipitating crystals set Gypsum to an ever increasing extent the setting of the raw mass so that after some Time can no longer be processed and loses its cohesiveness. It has now been found that by adding keratin-containing substances in liquid or soluble form to the mixing water the solubility of the gypsum is reduced so much that the amount of in solution and gypsum that crystallizes out when the water is reused is small. Thereby it comes between the accelerating effect of the crystallizing Plaster of paris and the retarding effect of the keratin components to a balance, which the setting of a suitable stiffening time enables the continuous operation same: stay.

In a further embodiment of the invention, the sulfatic Binding agent, preferably plaster of paris, with an additive to be added to the mixing water of delay means, e.g. B. Keratin products, in an amount of 0.1 to 1% of the binder weight is used. The strong solubility of calcium sulfate, which its use for the purpose of the invention has so far been opposed to it Addition of a retarder, e.g. B. of keratin products in amounts of 0.1 to 1% to the amount of plaster to be added. There is also a a favorable stiffening time for the production of the building structure. After that, the The addition of retarders does a double job by forming a membrane around the individual gypsum grains reduce their solubility and ensure a suitable stiffening time. The effect is best achieved when the retarder is in the mixing water when it comes together with the plaster of paris is dissolved.

As fabrics that are similar to fibrous materials to mechanical bonding of individual particles, namely tend to be felt-like clinging, come plant-based, animal, mineral and artificial fibers of all kinds as well as mixtures of different types Fibers into consideration, for example sisal, animal hair, slag wool, asbestos, Nylon and the like, including fish scales and mica. Tend to felt-like clinging but not only fibers, but also other sharp or beard-like edges having or twisted particles, as they are water-insoluble in the comminution solid substances arise, e.g. B. waste generated during machining, such as plastic turnings, metal filings or particles such as those produced by comminution from products obtained «earths which themselves consist of fibrous materials or fibrous materials contain; it can e.g. B. the softened parts of shredded, used paper sacks be used. Wood fibers, including mixtures with wood wool and, are also suitable Wood chips.

The excess water is expedient except by draining it off the document set up for this purpose also in a `` '' format that is also known per se removed by pressing, preferably by folding.

More than 8 to 16 times the amount of water by weight of the binder is used. The best effects are obtained when 10 to 12 times the amount by weight is used. The Abbindegeschw indigkeit is appropriately set so that the setting in terms of a noticeable stiffening after more than 10 to 500 minutes, z. B. after 120 to 300 minutes, preferably after 120 to 180 minutes, begins.

The binder can be added by clay in an amount up to a third replace the binder weight. The advantages of the method according to the invention are as follows: With the new process, plates of all kinds, but also Manufacture pipe, plates z. B. for the production of light partition walls, but also for cladding solid walls and ceilings and those used in place of plaster as "Dry plaster." Can also be used, as well as sound absorbing plates. An essential one The advantage is that the process according to the invention can be carried out continuously leaves. With the squeezed out water, almost no binder is lost because the water is used over and over again. The method according to the invention works compared to the known method for the production of plasterboard in forms without Waste.

Since all kinds of fibers can be used for plaster of paris binding without pre-mineralization are going to use also such fiber and waste materials possible, which are unusable for the production of cement-bonded panels. Since the measures according to the invention eliminate the risk of premature setting is can be done with simple. Mixing and conveying get along easily keep it clean. The use of an excess of water in the inventive Extent gives the slurry its preparation and. Facilitating further funding Nature. For all these reasons, the method according to the invention enables the cheap mass production of high quality gypsum structures, especially panels. Through this, that the before the start of setting is far higher than the t: ei of the use of Gypsum previously usual water content before the final shaping of the building to less The products become special when the usual content is reduced hard and firm. In addition to reducing the water content, pressing is beneficial also mechanically for compaction, e.g. B. by squeezing out air and gas inclusions. Because of the low water content, the blank produced can also be dried quickly. Gypsum boards produced by the method according to the invention are after drying ready for dispatch from a few hours, while cement panels before dispatch about 28 Need to tie days.

The plaster of paris structures produced by the method according to the invention are in contrast to the plasterboard produced in molds in the previously known manner almost unbreakable. They have high mechanical strength; for example Embodiment resulted in a flexural tensile strength of 104 kg / cm2 parallel to the direction of manufacture and of 117 kg / cm2 transversely to the direction of manufacture, furthermore a Hugel indentation hardness of 130 kg / cm2. Because of their greater strength, according to the invention Process produced structures can also be used as resilient structures. In. In the shape of a plate, they are so hard that they can be freely suspended over a large area can.

The advantages that are inherent in the previously known gypsum structures, are retained, so the low thermal conductivity and thus great thermal insulation, the incombustibility, its better time of resistance to the effects of fire as a result Release of water vapor and independence of manufacture from imports foreign raw materials. Compared to cement boards, gypsum fiber boards are due to their lower specific heat reduces the risk of condensation in Interiors smaller. The adhesion for plaster, wall or ceiling plaster is at Gypsum fibreboard better than cement-bonded or gypsum cardboard. The plasterboard is more elastic than a cement-bonded board. The manufactured according to the invention Products have no brittle plaster layers between the fibers or the fiber-like layers Components, but rather the components that are braced together like a felt are elastically connected to one another by the finest gypsum crystals, namely via the whole plate thickness.

In contrast, the plasterboard produced according to the invention shrinks not to cement boards; they grow so little that they do not pose any difficulties result. After all, they are far more versatile than cement fiber boards in interior construction.

That embodiment of the method according to the invention which the use of a hydraulic sulphatic binder, namely gypsum slag cement (Sulphate cement), in addition to air-binding agents such as gypsum, has the special Advantage, the advantages of the air binding agent and the hydraulic binding agent together to connect and to offer the possibility of the properties of the product through Change the binder mixture to vary.

The binders, the water and the felt-like bracing Tending substances as well as any fillers can be mixed in any order will. So the binders can initially under themselves and the binder mixture are then mixed with the fiber or fiber-like substances, and these Mixture can be mixed in water, which contains the amount of retarder determined to be suitable, be stirred in. But it can also contain fiber and filler initially with the retarder Stirring water and then adding the binder or binder mixture to the mixture can be added, or it can be added to the binder mixture mixed with water containing the retarder the pulp can be fed, and finally all the substances to be mixed can be added be fed to a mixing tank and mixed at the same time, only the water must the required amount of retarder must be added beforehand.

A device for carrying out the method according to the invention includes a mixer, a dosing device, a porous conveyor belt, or several suction devices attacking the tape, a winding drum for the fleece formed on the belt, at least one pressing device, e.g. B. a pair of rollers of the type used in board machines, or consisting of one Table and a roller pressing against it, possibly a second pressing device, which is preferably designed as a re-rolling device, and optionally one Stacking and drying device. The system is designed so that everything is running and squeezed water is returned to the mixing device until an operating period is finished.

Furthermore, the nonwoven fabric produced can be used prior to the start of production subjected to a special surface treatment of the setting, e.g. B. with special Surface layers are provided. The surface treatment can be in soaking with paint or in any other application of paint layers. Special surface layers but can also be in the form of sheet-like substances such. B. films, applied to the fleece will. The sheet-like fabrics can be printed and not just plastic films, but also metal foils or veneers. The fleece surface can also only are partially or in different patterns covered with such materials, which then form deposits in the surface. Finally, other liquid can also or semi-liquid substances can be applied as colors to a fleece.

If the plant has two nips, e.g. B. two at a distance from each other arranged roller mills, can be a surface treatment of the produced Run fleece advantageously in the area between the two pressing points.

Even in a first press station that works with rollers profile the continuous fleece in any desired way. The profiling can also take place at the second rolling point or be continued. A second The rolling point also has the advantage that the water is squeezed out even better and through additional compression of the continuous -'lie it The strength of the product is increased and the drying process is facilitated.

The surface treatment can also be a fine profiling: The surfaces can be rolled smooth or patterned.

It can be useful to have more than one mixing vessel in one and the same Use the facility so that one at a time can be cleaned while in operation continues with another.

The use of a take-up drum as used by the manufacture is known from asbestos cement panels and cardboard machines, makes the scope which is available for the wall thickness of the products is particularly large. Nice the fleece on the conveyor belt that allows the excess water to be discharged can be produced in very different strengths without affecting the uniformity of its Condition over the cross section damage suffered. By the well-known winding of the fleece on the winding drum, this strength can then be multiplied at will.

The drum with a brush that treats its circumference is useful equipped, which serves to remove the part of the drum circumference that remains free from the fleece or the drum circumference that has become free after removing the fleece clean.

This ensures that the surface of the subsequently generated The plate remains smooth, while otherwise a look on the drum shell becomes stronger and stronger adhering binder film would result in unclean panel surfaces. This approach This also prevents the winding drum from being powdered with the jacket or is treated with agents to be applied in liquid form, e.g. B. with silicone oils. The brush mentioned can also be used as an applicator, possibly with the additional use of spray nozzles.

A sub-invention is that a permanent coating of synthetic resin, z. B. Polyvinylclilc: rid. is firmly applied, preferably shrunk on , which also lines a groove extending transversely over the drum shell. This ensures that the surface of the gypsum fiber board removed from the drum is always as smooth as the surface of the 1 #: unstharzü coating, which is for their part, it is easy to keep the loads clean and undamaged. But if the outer surface of everything is hard-coated, it should be abandoned. then the coating loads easily and replace 'suspect huge costs.

Instead of a permanent coating on the take-up drum, it loads ensure the production of smooth plate surfaces also by the fact that the jacket of the Winding and winding drum before each application of a fleece: it with an easily removable, possibly lost cover of sheet-like material, such as silk rapier or resin film.

The drawing shows an exemplary embodiment in a schematic representation in FIG a system suitable for carrying out the described process: Fig. is a longitudinal section through the winding drum, FIG. 3 an associated end view, and Fig. 4 shows a detail of the take-up drum on a larger scale.

A mixing vat 1 is fed through a funnel 2 in the seal of the Arrow 3 pulp and through a funnel 4 in the direction of arrow 5 binder fed. A pump 6 is connected to the table tub via the nozzle 6 'delivers a powerful jet of water into the mixing tub. The water jet inherent energy ensures that the water with the fibers and the Binding agents are intimately mixed, so that a slurry containing a lot of excess water or suspension is formed in which the solid particles are in excess water are evenly distributed so that the mixture components together form a thin, Form slurry easy to handle. The pump 6 sucks the water out of one Reservoir 7 via a line 8. In the mixing tub 1 there is a Agitator 29 and a stripping roller 9.

Through the tub 1, the endless belt 11 is passed, with the the stripping roller 9 cooperates. The entry gap for the tape is with sealing lips Mistake.

The aqueous slurry 10 generated in the mixing tub 1 is through a suction head 17, over which the endless belt 11 runs, sucked on its surface. The suction head 17 connects to the underside of the belt 11 with sealing lips. The belt 11 runs over the rails 12, 13, 14, 15, 16, and 16 'and is in the direction of the arrow 11 'driven. It is made of water-permeable fabric. Under the one Section of the belt 11 with the pulp-binder slurry poured on it 10 is loaded, a suction head 17 'is arranged, which is provided with sealing lips 18, 19 connects to the tape. In the sow heads 17 and 9.7 'an air pump 20, which is connected to the suction head by a line 21, a negative pressure generated. The water sucked out of your pulp on the tape; ; will from the suction heads 17 and 17 'via lines 22 and 22' and the collecting line 23 to the reservoir 7 or the suction line of the pump 6 is supplied directly. From your dehydrated pulp is formed on the belt 11, a fleece 10 ', which over the Umlenhrolle 13 on a winding drum, the format roller 30, by means of a counter-pressure roller 31 pressed and wound onto the drum or format roller 30 several times on top of one another will.

The drum 30 consists of a cylindrical shell 56 (Figure 2), attached to the front sides by in it, z. B. welded circular disks 57, 50 is closed. Bearing hubs 51, 52 are fastened centrally in these disks, z. B. also welded. At one point on the circumference, the jacket 56 has a Groove 53 running parallel to the cylinder axis. At this point is the coat Reinforced on its inside by a strip 54. On the jacket 56 sits a Cover 55 made of synthetic resin. which is expediently attached to the jacket by shrink fitting is and also lines the groove 53.

The tape 11 is removed from adhering mixture residues, by means of an in Direction of arrow 24 rotating knocker 25 cleaned and then from spray nozzles 26, 27 sprayed with pressurized water supplied through line 28, so that it is cleaned in the mixing tub 1 continues, where it is again with a fiber-binder-Auf flood is loaded.

The nonwoven fabric wound on the drum 30 becomes when the winding has reached the desired strength, in a manner known per se by means of a while slit into the groove 53 (Fig. 4) engaging cutting knife and removed from the drum removed. It then arrives as a flexible plate 10 ″ on a conveyor belt 49. The flexible Plate or the further frozen Fleece eventually gets between the rollers 33, 34, which are pressed against one another in the direction of the arrows 35, 36 and squeeze off any excess water still contained in the fleece or the flexible plate. Following the pressing point formed by the rollers 33, 34 is shown in the case of the one shown Example, a second press point is provided, which consists of the table 37 and the in In the direction of arrow 39, roller 38 is pressed against the table. Instead of this the second press point could also be designed as a roller frame containing two rollers be, or vice versa, the first press station could also be from a table and consist of a counter pressure roller. Finally, only one press point could be arranged be. Both the rollers 33, 34 and the roller 38 can be profiled rollers which the continuous. Give fleece or panel blank a longitudinal profile, which later makes it easier to dry a stack. As mentioned above, the plates can by means of the rollers can also be given patterned surfaces, and between the nips the plate surface in another way, e.g. B. by applying special surface layers, treated additionally.

A cutting device is attached to the second pressing point, which is indicated by the arrows 40, 41. It is used when the fleece is cut continuously or if the panels to be produced are smaller should than corresponds to the circumference of the drum 30. The panels are then placed on top of one another at the cutting point to form a stack 42, expediently on one Lowerable table 43. Resilient bellows 44, 45, z. B. made of rubber or rubber substitutes, which the stack cross-section with a drying room 46 connect. When the panels are profiled so that they are gaps in the stack form, or if they are stacked with the interposition of strips, can an optionally heated air stream to accelerate drying through the Suck or blow stacks through. A carriage 47 is arranged in the drying tunnel 46, which can be moved under the stack 42 in such a way that it can then be lowered by the Table 43 can be moved away.

The line 48 indicates in the drawing that the entire water flowing out of the system, be it via the collecting tank 7, be it directly returned to the suction line 8 of the pump 6. Example 1 10 to 25 percent by weight Fibrous materials, e.g. B. softened, broken up used paper sacks are rated 90 up to 75 percent by weight of stucco and ten times the amount of plaster by weight of water bloated, with so much keratin added to the water as a retarder, that the suspension freed from excess water sets after about 2 hours.

Example 2 As example 1, but with replacement of one third of the weight of the stucco plaster by sound.

Example 3 A panel with a density of 1 contains 15% fiber weight and 851 / o calcium sulfate dihydrate weight.

With the gypsum fiber suspension according to the invention can be Otherwise known processes also produce pipes that have the same advantageous properties have as they have been described for the plates produced according to the invention.

Numerous elements of the for the implementation of the invention The system described in the method have characteristics that also apply during processing of aqueous suspensions made of fibrous materials and only hydraulic binders can be used advantageously '. This is especially true for equipping the take-up drum with a permanent cover made of synthetic resin and from the use of a permanent cover on the drum shell from a sheet of paper or foil or other suitable sheet-shaped materials. To that extent are the sub-inventions relating to the system not subordinate to the method according to the invention described at the outset, but rather ancillary.

The method according to the invention includes the possibility of application known other additives to non-hydraulic and hydraulic binders doesn’t work. For example, hardening agents known per se can be added to the material slurry or vice versa porosity-making additives are added, the latter z. B. when sound absorbing records should be generated. A suitable additive for this case is kieselguhr. Other additives can improve the surface quality, for. B. to Increase the surface smoothness. Finally, the chemical Improve the resistance of the body produced by known additives, see above z. B. by adding barium hydroxide the resistance to water and thus the weather resistance.

Claims (14)

PATENT CLAIMS: 1. Process for the production of structures from fibrous materials or similar substances which tend to mechanically bond individual particles or from substances to which fibers are mixed and mineral sulphatic binders, characterized in that from said fiber or fiber-containing substances and Gypsum or gypsum slag cements as a binder a slurry (suspension) made with a large excess of water and the addition of retarders, to one Preformed fleece and the main part of the water before the setting process begins Will get removed. 2. The method according to claim 1, characterized by the use of gypsum as an air-binding agent, with an addition of to be added to the mixing water Delay means, e.g. B. Keratin products, in an amount of 0.1 to 1% of the binder weight. 3. The method according to claim 1, characterized in that more than that of water 8 times and up to 16 times the weight of the binder is used. 4. Procedure according to claim 1 or one of the following, characterized in that a binder is used, in which the setting in the sense of a noticeable stiffening after more than 10 to 500 minutes begins. 5. The method according to claim 4, characterized in that that a calcium sulfate-containing binder is used, which after 120 to 300 minutes, preferably after 120 to 180 minutes, in the sense of a noticeable stiffening begins to set. 6. The method according to claim 1 or one of the following, characterized marked that the Binder in an amount up to one Third of its weight is replaced by clay. 7. The method according to claim 1 or one of the following, characterized in that the fleece produced before the beginning the setting is subject to a special profiling or with special surface layers provided by applying plastic, liquid or powdery substances will. B. Method according to claim 7, characterized in that on the fleece before printed and unprinted plastic foils, metal foils, veneers, Paper and the like sheet materials are applied. 9. With a device the two spaced apart pressing devices, e.g. B. roller mills, contains, carried out method according to claim 1 or one of the following, characterized in, that a surface treatment of the nonwoven produced according to claim 7 or 8 in Area between the two pressing points takes place. 10. Device for implementation of the method according to claim 1 or one of the following, characterized by the Arrangement of at least two mixing vessels (1) for the slurry for alternating operation. 11. Apparatus for performing the method according to claim 1 or one of the following with a winding drum for the fleece formed on an underlay tape, thereby characterized in that the drum (30) with a brush machining its periphery is equipped. 12. The apparatus according to claim 11, characterized in that the Brush at the same time to apply the sticking of the fleece (10 ') to the drum (30) the obstructive agent can be used, if necessary with additional use of spray nozzles. 13. Device for performing the method according to claim 1 or one of the following with press rollers for squeezing off the excess water, thereby characterized in that the press rolls (33, 38) a first (33, 34) and / or one second (39, 38) nip are profiled rollers. 14. Apparatus for carrying out the method according to claim 1 or one of the following with a winding drum for the fleece formed on a backing tape, characterized in that on the drum (30) a permanent coating (55) made of synthetic resin, for. B. polyvinyl chloride, firmly applied, preferably shrunk on, which also lines a groove (53) extending transversely over the drum shell. Considered publications: German Patent Specifications No. 810 977, 809 535, 908837; Vorreiter, "Handbuch für Holzabfallwirtschaft", 1943, pp. 352 to 358.