DE1696195A1 - Process and manufacture of paper for plasterboard and similar products - Google Patents

Description

No '.., ZS, ..'. Charlottenstrasse 58

Telephone 10114 Telegram address: Dabspatent

FLEMING & SONS, INC., 1120 Clarendon Street, Dallas, Texas (USA)

Process for the production of paper for plasterboard and similar products

The invention relates to a method for producing Paper for plasterboard and similar products.

The subject of the invention is the production of paper for both sides of plasterboard and similar products such as Plaster bases, plaster casts and the like, in particular the production of such paper on a Fourdrinier machine. The one in the following The chosen term "plasterboard" is representative of all types of building board products with a large, relatively thin core of hydrated plaster of paris with or without aggregates, the core being A cover made of relatively heavy paper is provided on both sides. The paper on the back or after installation the panel's concealed area is called the "gray back" and that after mounting the panel and usually with a Dyed or cement-coated exposed paper as

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"Cream-colored top". Furthermore, those will Sides of both paper supports that touch the gypsum core and with which the core is glued as the "adhesive side" of the paper, while the opposite faces are called the "exposed surface".

Plasterboard and similar products are known and widely used in the construction industry. A Paper overlay of very large rolls introduced into elongated molding machines, a layer of aqueous gypsum slurry in the desired Thickness applied to this paper and this plaster core covered with a second layer of paper. The plaster of paris is allowed to hydrate; it is finally cut into sections of the desired length, these sections then be passed through drying ovens. The adhesive surface of the paper should be so porous that a good connection with the plaster core can be made and that the exposed surface of the paper is water repellent and yet so sufficient Permeability means that the water vapors produced during the hydration and drying of the gypsum core can easily escape can. Since the plaster of paris core has practically no breaking strength, it also appears expedient for the paper to have a certain Has minimum tear strength in both the longitudinal and transverse directions.

So far, both the gray backs and the creamy

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colored surfaces in general on cylinder mold machines produced, the pulp in successive layers to form 4 to 8 layers in the Machine was entered to give each layer the desired properties and so a paper in the to produce the desired quality on both sides. Paper produced on such cylinder mold machines for the production of plasterboard has a weight of approx. 52.6 kg

ρ
per 92.9 m, and since this paper is sold by weight, like the advantage lies in a reduction of this weight on the hand when the paper-target thickness or - strength can be maintained. In the case of paper produced on cylinder mold machines, there is also a tendency that the fibers are aligned in the longitudinal direction of the sheet, as a result of which the strength of the paper in the longitudinal direction is about 3 to 4 times as great as in the transverse direction. The tensile strength of this paper produced on cylinder mold machines is approx. 16.1 to 17 * 8 kg / cm in the longitudinal direction and 4.6 to 5.4 kg / cm in the transverse direction. A paper should therefore be created in which the tensile strengths are almost the same in both the longitudinal and transverse directions.

After it was generally considered impossible to use plasterboard paper on a Fourdrinier machine in one layer or at most two layers produce and provide the respectively desired qualities of the paper in this way, this is with the

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The method according to the invention is now possible. The paper is lighter (weight 22.7 to 27.2 kg per 92.9 m ² ) and therefore cheaper ^{per m 2.} The tensile strength in the longitudinal direction is about twice as great as that in the transverse direction compared to a ratio of approx. 4: 1 for paper produced on cylinder mold machines. The fourdrinier paper has a tensile strength in the longitudinal direction of approx. 9.5 to 12.5 kg / cm and that in the transverse direction of approx. 4.6 to 7 * 1 kg / cm. These strengths are perfectly within the limits permissible for the production of plasterboard and are in accordance with the regulations of the American Society for Testing Materials (US materials testing agency), hereinafter referred to as "ASTM", and the Technical Association of Paper and Pulp Industries (Techn. Fachverband Papier - and cellulose industry), hereinafter referred to as "TAPPI". The paper also meets the requirements of the scoop test for the dimensioning of cardboard, TAPPI test method RC-68, as well as the Gurley ¹ see permeability test for determining the air penetration resistance of paper, TAPPI test $ -46O-m-49. The requirements to be met by this paper were determined according to ASTM specification C 36-55, the standard regulations for plasterboard, and the strength tests according to ASTM test method C 26-56, standard method for testing plaster of paris and gypsum products. The scoop test according to TAPPI RC-68 has been modified so that instead of boiling water, a

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Water with a temperature of approx. 52 ° C was used, as this is roughly the highest temperature that the paper has during the course of the production of the plasterboard during hydration and should reach before the final drying. This modified test gave a water resistance of 300 Seconds and above. Gurley's air resistance or porosity test gave results from about 11 to 15 Seconds. Gypsum boards manufactured using commercial-grade Fourdrinier paper in a plasterboard factory had breaking strength values of according to ASTM test C 36-55 52.15 to 72.6 kg across the plate and from 29.5 to 36.3 kg parallel to the plate edge.

The gray side and especially the cream-colored surface of the previously used for the production of plasterboard and similar products The papers used can either be completely coated or by applying designs do not print, mainly due to the fact that the paper grades used already have a have such a high porosity or lack of vapor permeability that the additional application of pressure or Coating materials reduce this vapor permeability even further in such a way that moisture can escape from the hydrating or hardening plaster of paris is delayed too much and drying the plate in the oven with the resulting water vapor leakage this

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escaping water vapor effectively blows away the paint or the applied coating material. So could

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Sffected or printed panels can only be produced by coating or printing a separate paper layer and subsequently applying this to the finished panel at a correspondingly higher cost. Thus, a further object of the invention is to create an improved method which, if desired, includes coating or printing the plasterboard paper prior to the actual formation of the plasterboard, with complete and satisfactory adhesion of this application or printing being ensured during the entire subsequent plasterboard manufacturing process .

Furthermore, the pre-printing can be done using special paper for using the acid or alkali method take place.

Also, any type of fiber suitable for papermaking, including sawdust, wood shavings, wood pulp, or other waste products for processing the paper pulp in addition to the 1> isher normally used, such as e.g. different types of waste paper, scrap paper and the like can be used.

The invention is illustrated in the drawing from two exemplary embodiments. Show it:

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1 shows a machine for carrying out the method according to the invention in a schematic representation and FIG

Fig. 2 shows a modified embodiment.

In carrying out the process, conventional methods of composing the paper pulp are used, using relatively short fibers which not only allow the plasterboard to break more easily during trimming or installation, but also in a smooth break of this board with relatively clean and torn off Fiber ends free edges result. Many types of cellulose fibers can be used in the context of this process, for example in the composition of 40 % cardboard traps or plasterboard scraps or other short-fiber material, JO % new corrugated cardboard cut and 30 % old corrugated paper, all in weight based on the dry or solids content of the pulp. The material is mixed with enough water to make a pulp with a solids content of egg. % Placed in a conventional pulper, where it then passes through corresponding channeled or Absetztröge, remove the precipitating sand or dirt to - 0.8 to 1 wt.. The pulp then passes into the thickener, in which the solids content is concentrated to approx. 3 wt .- ^ and the waste water is fed back into the pulper.

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The thickened pulp now goes into the storage silo, where it is continuously moved by an agitator, and is then passed to a further apparatus for dispersing and shortening the fibers by cutting or shearing. here a certain gelatinization of the fibers occurs. The pulp is forwarded to the chute of the machine, another storage station, and then to the measuring or filling box, part of this pulp flow from here into the head or loading box on the Fourdrinier machine and another Part flows back to the machine's vat. Thus, there is a sufficient supply of pulp to the head box guaranteed.

Throughout the pulp delivery and papermaking processes can choose any or all of the upcoming Facilities and procedural phases are consulted and applied.

In the head box, but better at a point before this in the system or even at the beginning of the same, a sufficiently large amount of an alkaline material is added to the slurry to bring about a pH of about ¹ to 9. This alkaline material can be caustic soda, soda ash

ka
or a similar, inexpensive Al / i) lizing agent, it being advantageous, as mentioned above, to keep the slurry within this pH range during the entire course of the process.

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On or in front of the head box, the paste becomes resistant to alkali water Binders such as alkyl ketene dimers of a fatty acid from the group of palminic, stearic, myristic and oleic acids along with? a sufficient amount of a holding agent that a holding of the binder within the Paper body ensured during the subsequent treatment or during the production of the plasterboard, added.

The binder must be water-resistant (water-repellent) in alkaline media, and this up to a certain temperature of 60 ° C. A number of such agents are commercially available and others are under development.

The holding means can be any suitable alkali-resistant, water-resistant, cationic thermosetting resin and, if desired, also an aqueous solution of such a resin as a reaction product of epichlorohydrin and polyalkylenepolyamine with dicarboxylic acid - selected from the group consisting of diglycolic acid and C 1-8 saturated aliphatic dicarboxylic acids. Binding and skin agents can be used simultaneously in water solution or dispersion in a ratio of 10 to 20 gallons with 6 % solids for the binding agent and 10 gallons with 10% solids for the holding agent and using a sufficient amount of water to make a mixture of 150 Gallons are added.

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In one case where the papler fiber mass was added to a Fourdrinier machine in an amount of 85 tons per 24 hours in the form of a dispersed aqueous pulp with 0.8 to 1 wt .- ^, the addition of this aqueous solution of the binder and the holding agent was carried out at one speed of approx. 22.7 l / min. Thus, the binder is added in a ratio of approx. 1/3 to 2/3 of 453 ß per ton of fiber material and the holding agent in a ratio of approx. 1/2 of h 453 ß per ton of fiber mass.

The initial alkalinization of the pulp is assessed and determined according to its pH value, with the use of Caustic soda approx. 2 engl. Lbs. And when using calcined soda approx. 5 engl. Pounds per ton of pulp are required. In any case, the additional amount is based directly on the required pH value range of 7 to 9

The thin felt or the thin mat made of fiber mass with a still high water content continues to run in the usual way through the Fourdrinier machine, gradually squeezing out the water and transforming the felt into a sheet of paper. The adhesive surface is in the smoothing calender section of the machine of the paper by simply rinsing it with water to remove internal tension in the paper and a later To prevent the paper from throwing or curling during the subsequent production of the actual plasterboard.

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The exposed paper side is also treated in this wet smoothing calender section by being washed over with an aqueous emulsion or a suspension of a wax emulsion or a suspension composed of wax emulsion and modified starch. Such a suspension should contain 3.6 to 14.5 kg of aqueous wax emulsion with approx. 46 wt .- # of fully refined paraffin wax per 378.5 liters of water, with the use of starch this suspension between 2 ^ 27 and 22, ä 68 kg modified starch per 378.5 liters. water must contain. Such a wax emulsion or wax emulsion / starch treatment of the paper is known.

Following this treatment, the paper is taken to the drying stack and finally peeled off and as usual wound on a roll.

The following results were obtained for two paper rolls produced according to the method described above: "

ROLE NO. 1 2

Thickness in mm

Weight in kg / m

Saturation, 52 ⁰ C, modified scoop sample

Longitudinal Tensile Strength, kg / cm

in the transverse direction

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0.4495 0.5207 0.25388 0.31589 20 min. + 6 min. 10 12.14 6.07 6.96

Porosity, Gurley test, sec. 1J.2 11.5

Transverse breaking strength of the gypsum board, in kg (across the board
away) 59 * 3 52.05

Obviously, cream-colored paper can be made by the same process. All that is needed is a thin layer of light-colored paper pulp on the first pulp layer using an additional Head or task box or any other suitable device applied. Otherwise the procedure is exactly the same.

The drawing shows a fourdrinier machine in a purely schematic form, on which the above-described procedure can be carried out. This machine includes the usual Head or loading box 10 for receiving the alkaline paper pulp 11 with the binding and holding means contained therein; From this box, the pulp goes to the usual fourdrinier wire 12 of the machine and then to the various Processing calenders IJ. When the paper reaches the wet end 14, the adhesive surface of the same is flushed over in a conventional channel 15, and the exposed paper surface with the wax emulsion or the wax emulsion / Starch mixture by rinsing from a second channel 16 treated and processed. The paper is then given a finishing treatment that is customary in this field, such as trooken abatement.

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cut 17ί and made into a large compact roll 18 wound.

The process not only results in a considerably lighter and therefore cheaper paper for the production of plasterboard, but rather a paper with more even tensile strength in its longitudinal and transverse direction, but that nevertheless unusual in view of its light weight is strong. Due to the good adhesion and adhesive properties of the paper adhesive surface, an excellent connection with and ensures adhesion to the plaster core of the panel; the greater permeability or porosity allows much faster production of the plasterboard than was the case with the papers used earlier. This means that the gypsum board making machine with a higher speed or with a higher production rate and the drying oven, which the plates have to pass through can be run at lower drying temperatures. This is whole apparently due to the higher porosity, which means that moisture is expelled from the plate more quickly in such a way that the finished product can be used immediately.

Although the basic process described above is to be regarded as more advantageous, an acid process can also be used be worked with the feed material in

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the composition of approx. 40 % cardboard scraps or gypsum (board) shredded paper or any other short-fiber material, 30 % new corrugated cardboard sections and 30% old corrugated paper, all based on the weight of the dry or the solids content of the pulp, can be used Again, all suitable types of paper fiber materials, for example any wood waste, are used here. This feed material, which can have a pH value of 4.2 to 4.5, is as far as possible to 3 · 5 to 5 »] 6ένοτ-

however, reduce to 4, by adding alum

or alum plus alumina soda with a pH value of 5 to 6.5 or at least very slightly acidic, because, the higher the acidity of the feed material the more brittle the fibers in the finished paper will be. When using alumina soda is at least a small one Amount of alum to be added, but the binding is still done with the help of a saponified rosin-alum additive even if the pH value may be very or almost imperceptibly close to 7.

In addition, as the paper dries while it is passing through the Fourdrinier machine, there is bound to be a Increase in the acid concentration and further embrittlement of the fibers. This means that the resulting Paper is not so elastic, which should be irrelevant for plaster of paris or plasterboard. The tensile strength

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of the paper is not affected, but causes the Embrittlement of the fibers results in a smoother and cleaner break of the plate when it is adjusted to size and shape during installation.

Essentially, the above-described paper-making process passes using a "Fourdrinier machine are used, while the Beschiclcungsmasse with enough water to produce a slurry having a solid part share of ä 0.8 to 1 wt - is fed% the pulper or the dewatering machine and the slurry anschlieiend the corrugating. - or settling troughs for the separation of dirt and foreign matter or such materials, including sand, which settle in the course of this treatment, passes. The pulp is then conveyed to the thickener, where the pulp solids content is increased to approx. 3 % while the separated water is returned to the pulper.

Following this, the pulp is treated further in a conventional manner, ie a water dispersion or emulsion of a saponified rosin as a binder, which is a 0.4 % strength rosin dispersion, is used in an amount of approx. 0.2 to 00 wt .- ^ based on the dry basis of pulp fiber content is added.

The alum reacts with the rosin to form Alum resinate and can be added at any point

even the dry pulp shortly before its 109847/0376

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Entry into the head box of the Fourdrinier machine; aside from that this alum can be any commercial grade of sodium aluminum sulfate.

Then the paper pulp, from which the water is gradually drawn off, and the paper sheet that is finally formed pass through the same processes as in the conventional Fourdrinier method; In the calenders, the paper can be used on both sides 15 and 16 according to FIG. 1 are subjected to a water treatment in order to prevent the formation of bumps or waves, such as they are known to those skilled in the art to prevent as the paper passes through the plate making machine. It turned out to be Expediently, the adhesive side of the paper in this phase with an aqueous lye with a pH of about 11 or treat over it using soda ash to remove the binder from that side; furthermore, any suitable rewetting agent can additionally be used can be applied, which helps the gypsum paste to penetrate the adhesive side of the paper. A suitable rewetting agent would be Wyandot Pluronic L ~ 6l or a similar product of this type; these agents are mainly bulk polymers, consisting essentially of a polyoxypropylene chain with polyoxyethylene groups at each end with molecular weights from 900 to 35OO or as desired. The exposed one It is advisable to treat the paper surface in the usual way with a known wax emulsion or starch solution.

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The rinsing with water, the desizing, the job of wax emulsion or any other rinsing application for one or both sides of the paper is known.

The papers produced either by the alkali or the acid process as described above have a considerable porosity for the production of plasterboard, which is measured and expressed by the number of seconds required for a prescribed amount of air or other powder under one a given pressure penetrates a given paper surface: the greater the number of seconds or the longer the time taken, the lower the porosity of the respective paper; However, it is also customary to express the porosity in the time determined in this way in seconds, the paper being considered highly porous if the measurement is made using a Gurley ¹ see permeability tester, while this expression actually means that the paper has a lower porosity because a long period of time is taken during which a fixed amount of powder penetrates the paper. The cylinder mold papers currently used to make plasterboard have porosities of about 100 to 200, although a porosity of about 75 is the target, these numbers representing the number of seconds required for a given amount of powder to pass through. The papers produced by one of the processes described here have porosity

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would do from 8 to 20 or 30 seconds and are therefore far more permeable to air and therefore also permeable to water vapor than the papers previously used.

This means that the papers produced either by the alkali or the acid process as described above are different • Can be easily coated or printed or both / i and the finished paper has more than sufficient porosity for use in a plate making machine, may ^ This also reduces the porosity or the Porosity number (in seconds) be increased.

According to the foregoing, a considerable number of different procedures are possible insofar as the cream-colored side of the paper can be printed with any suitable design, coated in any color to form a solid design, and this order can be printed with any suitable design. Fixed designs such as wood imitations can also be applied. A 'more interesting alternative is the possibility of a gray area of relatively good quality with a light coating in such a way to completely coat, that it instead of the usual cream-colored surface may be used, said paper is composed practically single-layered and can be produced with considerable savings .

The coating or printing can be carried out at any point on the drying section, as shown in FIG. 2 at 19,

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between the drying section 1? and that shown at 20 Roll 18 or in a completely separate process after production and winding for Role l8 done.

The coating or printing can be carried out using conventional printing processes, using templates or by creating a background or design according to any one any of the methods customary in the printing industry can be carried out.

The paper can be coated more heavily, for example with clay, titanium dioxide or other well known materials, and in the area of the dry or wet section, e.g. in the smoothing press, or after the Paper. It should also be noted that a fixed pattern or design such as wood grain imitation on the gray reverse side can be printed without the need for a cream colored area for this purpose, and many other variations are possible due to the fact that the paper initially has such a low porosity that that a considerable amount of additional coating material or additional printing ink can be applied without reducing the porosity beyond that required for the plasterboard industry acceptable values increases.

To determine the coating materials or the amount of

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To keep the printing ink or other materials used to a minimum, any conventional materials can be used to increase the wear or press resistance for surface treatment or finishing, such a measure not only increasing the wear or pressing resistance, but also the parbene absorption capacity is reduced if the panel is to be painted after it has been installed. Furthermore, such a treatment results in an improvement in the print quality and a lower consumption of printing ink or other coating or printing material, since one of its punctures is the reduction in the absorption capacity of the paper. In this context, this absorption capacity should not be confused with porosity, since the latter relates to the speed of the passage of steam or vaporous media, e.g. air or water vapor, whereas the absorption capacity refers to the speed with which the paper absorbs a liquid like this one after the scoop test referred to above as TAPPI test RC-68 was demonstrated by way of example. In this context , it should be pointed out that the paper produced by the acid process can be tested in boiling water instead of in water at a temperature of 52 ° C., which appears more suitable for paper produced with a base, in order to determine a representative value.

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The method disclosed in this description therefore relates not only to methods of paper production, but rather furthermore also on methods which the printing or coating of the manufactured according to the respective process Including paper before processing it into a plasterboard, a process that was previously not possible was still thought possible. Papers printed or coated in this way are capable of drying oven temperatures.

to withstand temperatures of 149 - 205 ° C without damage and lead to the production of very attractive plasterboards, previously decorated and ready for installation and no longer require any decorative treatment.

Various modifications of the methods are possible without departing from the scope of the appended claims.

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Claims (15)

Patent claims: 1. Process for the production of paper with an adhesive side and an outer side for plasterboard and the like Products, characterized in that a thin, aqueous slurry of paper fibers is prepared, the pH value of this pulp to a level for the later ^ appropriate value is established during the driving phases, a water-repellent binder that is water-repellent or resistant up to a temperature of at least 60 ° C is added to the pulp, the pulp for the purpose of keeping this binder available, at least in the adhesive side of the paper is treated at least until the pulp is dry to paper, the so produced The pulp is fed into a Fourdrinier machine and the resulting paper is dried to the desired water content the adhesive side of the paper in the area of the calender w stations are irrigated and the exposed paper surface in the calender stations is finished with an aqueous solution selected from a group comprising an aqueous wax emulsion and a combination of starch and aqueous wax emulsion solutions. - 23 109847/0376 2. The method according to claim 1, characterized in that a surface ornament directly on at least the exposed paper surface is applied before the actual production of the plasterboard. 3 · The method of claim 1, characterized in that a surface coating at least λ listed directly to the exposed surface of the paper produced in this manner prior to the actual manufacture of gypsum board is introduced. 4. The method according to claim 1, characterized in that a surface coating and an ornament directly on at least the exposed surface of the such produced paper is applied before the actual production of the plasterboard. 5. The method according to claim 1, characterized in that a surface ornament by way of a printing or ' Coating process directly on at least the exposed one Surface of the paper produced in this way is applied before the actual production of the plasterboard will. 6. The method according to claim 1, characterized in that the binder is water-repellent in basic media. - 24 109847/0376 7. The method according to claim 1, characterized in that the pH of the pulp is in the range of 7-9 is set up. 8. The method according to claim 1, characterized in that the binder is an alkyl ketene dimer of a fatty acid from the group of the palminic, stearic, myristic and oleic acids is used. 9 · The method according to claim 1, characterized in that a aqueous solution of a water-soluble cationic thermosetting resin is added, which is a product from the reaction of polyalkylenepolyamine and dicarboxylic acid from the group which is selected from Diglycolic acid and Cj5 to C8 saturated aliphatic Dicarboxylic acids. 10. The method according to claim 1, characterized in that the binder is resistant to alkaline water and is added in an amount of 0.3175 kg per ton of fiber material . 11. The method according to claim 1, characterized in that the treatment for holding the binder in the paper is added in the amount of about 0.227 legs per ton of fiber mass. 109847/0376. 25 - "^" 1636195 12. The method of claim 1, dadurda in that the wax and starch emulsion by wetting the exposed surface of paper with an aqueous dispersion of 3.63 to 14.51 kg wax emulsion with about 46 wt -.% Fully refined paraffin wax and from 2.267 to 22 , 67 kg of modified starch per 378.5 liters of water is applied. 13. The method according to claim 1, characterized in that that the pH of the pulp is reduced to approx. 3 · 5 to 5 aligns, a binder is used on the bas / es saponified rosin alum and the adhesive side of the Paper is finished using water with a pH of about 11. 14. The method according to claim 1, characterized in that the pH of the pulp is set to about 3 * 5 to 5 , a binder made of saponified rosin-alum is used and that the final treatment the paper adhesive surface using water with a pH of approx. 11 and a wetting agent is finished from a bulk polymer which is essentially a polyoxypropylene chain with polyoxyethylene groups at each end and a molecular weight of 900 to 3500. - 26 -109847/0376 15. The method according to claim 1, characterized in that the exposed paper surface with a
Material is treated to increase wear resistance and reduce absorption. Br 109847/0376 Blank page