DE2713311C2 - Process for the production of paper, cardboard or paperboard - Google Patents

Description

The invention relates to a method for producing paper or cardboard according to the preamble of claim 1.

Numerous processes are known, instead of cellulose, natural fibers or a number of synthetic fibers to be used for the production of paper. These known processes in which cellulose is replaced by others Materials are to be replaced, but so far could not be carried out in an economical manner, for example because of insufficient binding capacity, because of chemical incompatibility or because of Difficulties in processing in paper machines. It has also been proposed to use starch fibers to be used in papermaking. Well-known proposals of this type could also be used so far cannot be realized commercially, which is why paper has so far been made almost exclusively from natural cellulose was produced, although the available wood supply is decreasing.

Aqueous systems normally used in papermaking require pulp fibers that have a have sufficient insensitivity to water, so that they are relatively in the manufacture within large ranges of pH do not lose their integrity. With a well-known proposal to replace Ccilulusciasern with starch fibers (US-PS 16 82 293) a chemical modification of the starch is necessary to its natural properties practically change before fiber formation and thus a degree of insensitivity to water achieve what is required for papermaking. In another known method (US-PS 25 70 449), however, it is necessary that the paper production itself by replacing the usual aqueous system is modified with an alcoholic solvent in which the starch fibers are not soluble are. Therefore, processes of this type are relatively cumbersome and uneconomical.

In papermaking it is also often necessary to add additives to the pulp in order to achieve specific To effect properties of the finished product. Additives such as pigments, latex, synthetic microspheres, fire-retardant fabrics. Dyes or perfumes are often used in the manufacture of paper. Effective retention of these additives in the wet end of a paper machine creates difficulties for the manufacturer, because the portion not withheld is not only an economic loss, but also means a considerable risk of contamination if it gets into the sewage system. Such additives are also used in common coatings or saturation V ' related. In this process, additional thermal energy is usually required for drying the paper again after making the Upper pull. Furthermore, solvents are required in certain cases for the production of the coating, which are very cause substantial costs and require a control for the recovery of the volatile substances.

It is therefore the object of the invention to provide a system while avoiding the above as far as possible Disadvantages and difficulties of a more economically feasible process for the production of paper. carton or to indicate cardboard in which starch fibers can at least partially be used instead of cellulose. This procedure aims to ensure a satisfactory retention and absorption of additives during be possible in papermaking, in particular the absorption of water-insoluble additives, to be incorporated into the paper as fiber encapsulated additives. Furthermore should the process enables the binding of synthetic fibers and / or natural fibers in a non-woven web form.

chen. After all, the process is intended to be used to produce both ordinary and higher quality Paper be possible.

In a method of the type mentioned at the outset, this object is achieved according to the invention by the Subject matter of claim 1 solved. Advantageous developments of the invention are the subject of Subclaims.

The task at hand can therefore be achieved in that starch fibers that are insensitive to water, that by precipitating a colloidal dispersion of starch into a coagulating salt solution instead of cellulose or a portion of cellulose or instead of similar fibers are used, which were previously used in papermaking. The fibers can be used for stretching the pulp, for embedding additives in the paper, as a binder for the fibers in non-woven fabrics Or any combination thereof.

The terms "paper" and "cardboard" should be used in the following material layers and molded products of fibrous, cellulosic materials as well as of those fibrous materials made of plastics (such as polyamide, polyester, rayon or polyacrylic resin), mineral fibers (such as asbestos or glass) and the like are made.

The term "to" usual papermaking hereinafter the object of an aqueous slurry of wood cellulosic fibers (which have been processed, for example in a hollander or treated to achieve ation to a certain Faserhy ^'r, and which functional additives can be added) onto a screen or the like means from which the water is removed to form a web of fibers which, after pressing and drying, can be processed into a dry roll or paper web. Furthermore, it is to be understood as meaning customary processes for the production of wet and dry-laid, nonwoven webs.

A particular advantage of the invention is seen in the fact that an additional source of raw materials is economical Way is usable. There is also greater flexibility in papermaking. It Starch fibers can be produced in dry or wet form and stored for subsequent use or the papermaker can consider producing starch fibers in his facility Provide an integrated stage in the manufacture of the pulp and / or paper.

Furthermore, there is the advantage for the manufacturer that Additives can be embedded in the paper with increased retention capacity, so that the Loss of valuable substances is lower and there is no pollution of the wastewater. As As mentioned earlier, it is common in papermaking. Additives associated with the fibers in the To introduce pulp. Such additives are embedded in order to give specific paper properties that differ from the properties that can be attributed to the fibers themselves. Such Additives are materials that act as pigments (e.g. titanium dioxide) as well as other materials which are added to improve the quality of the paper in terms of brightness, light impermeability, smoothness, Capacity for ink or dyes, fire resistance, water resistance or the like Achieve improvements. According to one embodiment of the invention, starch fibers can be made that contain various functional additives, which fibers in the aqueous Manufacturing phase can be used, with the retention capacity of the additives in comparison can be increased considerably to known processes. In addition to the increased capacity for restraint Another advantage of adding additives in this way is that it does not affect the sensitive balancing relationship between the cellulose fiber additive and the flocculant (e.g. alum) or other additional restraint measures must be taken. Rather, it is not required a flocculant or retention aid in conjunction with the starch fibers in the To provide methods according to the invention.

It has also been found that nonwoven webs can be made in wet or dry-laid form using starch fibers in the web as a binder therefor. The starch fibers can remain in the finished web or they can also be removed, for example if the main part! of the fiber material in the web is not flammable.
The invention particularly relates to a method of making paper in which an aqueous slurry of fibrous pulp material is applied to a screen in such a way that the water is removed therefrom and a layer of consolidated fibers is formed which, after pressing and drying, forms the finished paper product According to the invention, between 1 and 100 percent by weight of the pulp are used in the form of starch fibers with a diameter of 10-500 μm, which are produced by extrusion of a thread-like flow of a colloidal dispersion of the starch with 5-40 percent by weight in a moving coagulating bath which is an aqueous solution of a coagulating salt from the group consisting of ammonium sulfate, ammonium sulfamate, monobasic ammonium phosphate, dibasic ammonium phosphate and mixtures thereof, which solution contains the coagulating salt in an amount which is at least sufficient to coagulate the starch.

In summary, therefore, the essential features of the invention in a method for The manufacture of paper, cardboard and cardboard can be seen using starch fibers that are insensitive to water made by extrusion of a starch dispersion into a coagulating solution, to at least a portion of the cellulosic or

so to replace other commonly used pulp. Functional additives can be used in this process be introduced into the paper during its manufacture. Furthermore, the method for binding Fibers are used in nonwoven webs.

Preferred exemplary embodiments of the invention are to be explained in more detail below.

The method according to the invention is in connection with conventionally known devices and Process usable, but differs from known processes in that the entire Cellulose pulp or a portion thereof is replaced by starch fibers.

The starch fibers can be produced in different ways, but the requirement increases is that the water-insensitive fibers have a diameter of 10-500 μm and by extruding a filamentary stream of a colloidal dispersion of starch at 5-40

Weight percent solids are precipitated into a moving coagulating saline solution.

Fibers derived from any naturally occurring or fractionated fibers can be used Strength are made. For example, starch from grain, corn, rice, tapioca, wheat, potatoes, High amylose grain starch or commercial amylose powder along with natural Corn starch is used, tapioca and corn from v. are preferred for economic reasons.

The concentration of the starch solids in the dispersion is between 5 and 40 percent by weight When higher concentrations of starch solids are used, the difficulty arises that the The resulting dispersions are very viscous and special equipment is required for their treatment will. However, the specific concentrations present in the dispersions influence the properties of the finished fibers and the desired end use. For example, starch fibers are made from Dispersions with 5% solids were made, especially for making glassine or paper other greaseproof paper, while starch fibers from dispersions with 15% solids for more porous paper such as filter paper are better suited.

The starch concerned must be used in the form of a colloidal dispersion. In this In context, the term "colloidal dispersion" means a dispersion of starch that is practical is free from grains and has little gelatinization at the temperature at which it is to be used or shows precipitation. This state of dispersion can be achieved with the help of a large number of different measures that depends on the starch base used, the desired end use, and the available Depend facility.

For example, if cornstarch with a very high amylopectin content is used, a suitable colloidal dispersion can be prepared simply by boiling the starch vigorously in water will, «being no chemical additives or Modifications Are Required When starch with less than 95% amylopectin is used, this is one chemical modification of the starch expedient so that a colloidal dispersion is ensured before they is added to the aqueous system. The modification is made to the extent that the manufacture of the desired colloidal dispersion is guaranteed without affecting the properties of the starch, afterwards to be able to be precipitated. If no objection to the presence of caustic in the System exist, the last-mentioned strengths can be in aqueous sodium hydroxide, or potassium hydroxide other alkalis can be dispersed. Furthermore, the starch base can also be used in a smaller amount organic solvents such as dimethyl sulfoxide are dispersed and then mixed with water, or the Starch base can be used in conjunction with chemical additives such as urine and / or paraformaldehyde be dispersed. If alkalis are added, their amount must be sufficient and the strength in an adequate amount Disperse amount. Typical alkali amounts are 15 ^ 40 percent by weight sodium hydroxide * based on the weight of strength.

During the production of the starch dispersion, the starch added to the dispersing medium becomes strong stirred until the state of a colloidal dispersion is reached. In the FiIIi; dilute dispersions of Starch (about 5-10 percent by weight starch solids) takes about 45 minutes. At higher Concentrations of starch dispersions or with certain chemically modified starches requires longer periods of time and / or moderate application of heat.

For most starch dispersions, including corn and most chemically modified starches, cooling to room temperature can be carried out prior to introduction into the coagulating bath. at some little chemically modified starches prefer the dispersions for about those to use elevated temperatures at which they are made to the required colloidal Maintain dispersion and enable high efficiency fiber manufacture.

The coagulating bath for the production of the starch fibers consists of an aqueous solution with special Ammonium salts from the group consisting of ammonium sulfate, ammonium sulfamate, monobasic and dibasic ammonium phosphate and mix? of that. It is also possible to use the mentioned functional "! Salts" with others to combine compatible salts, which form a starch precipitate, in order to achieve a satisfactory coagulation and to enable a fibrous product. Examples of suitable substances for this purpose are ammonium persulfate. Ammonium carbonate, ammonium bromide, ammonium bisulfite, ammonium nitrite, ammonium nitrate, Ammonium bicarbonate, ammonium oxalate, sodium and potassium chloride, sodium and potassium sulfate. in the there is generally no benefit in using these additional salts because of ammonium sulfate. Sulphamate or phosphate salts must nevertheless be present in their respective minimum amount.

to cause coagulation. However, the presence of significant amounts of other salts can then be desirable when using a recirculated coagulation bath in which generated in situ Salts are present, as will be explained in more detail below.

The minimum concentration of salt required for coagulation and the preferred salt or the preferred salt mix will depend on the starch base in question. For example in the case of Corn starch, it is necessary that at least 35 percent by weight, based on the total solution, Ammonium sulfate are present, 72% (saturation) ammonium sulfamate, 37% dibasic ammonium phosphate or 40% monobasic ammonium phosphate.

With starch such as corn starch, which contains about 54-80% amylopectin, low salt concentrations can occur be used, for example 20% ammonium sulfate, 50% ammonium sulfamate, 25% monobasic Ammonium phosphate or 30% dibasic ammonium phosphate. In the case of hybrid corn starch with Less than 50% amylopectin Piwa must contain ammonium sulfate in an amount of at least 15%, ammonium sulfamate in an amount of 40%, dibasic Ammonium phosphate in an amount of 25% and monobasic ammonium phosphate in an amount of 20% must be present.

When using alkaline starch dispersions Alkali salts produced in the coagulant bath, a satisfactory production of the desired starch fibers continues until the amount of SaUcs generated is relatively large. The tolerance amount for the salt produced, above which the production the fibers are no longer sufficiently satisfactory,

depends, for example, on which particular salt is used, the total amount of solid salts what is used is what the concentration of starch solids is in the dispersion and the amount of amylopectin in the starch base. As soon as this tolerance level for the salt is determined, one can steady state at this maximum level (or a lower level) due to the periodic addition of Ammonium sulfate can be obtained in a continuous manner. For example, if sodium hydroxide is used as a dispersing medium is used, and when the starch mixture is placed in a coagulating bath with ammonium sulfate is extruded, sodium sulfate is formed. In this context it was found that the Manufacture of corn starch fibers (13% solids in dispersion) to a satisfactory extent continues until a maximum of about 70 parts sodium sulfate per 30 parts ammonium sulfate (44% Solids in the solution) in the bath is achieved. Upper At this level of sodium sulfate, the efficiency of making starch fibers will be lower and the manufactured fibers show a tendency to lose their individual integrity. By adding a small amount of an inorganic acid to the initial coagulating bath or bath however, during the formation of the fibers, the level of salt produced in the system can be substantial must be raised before the production of the fibers is significantly affected. In the case of the above Example leads to the addition of only 3 parts of sulfuric acid per 100 parts of the initial Coagulating bath added salt to a tolerance level of 90 parts sodium sulfate per 10 Share ammonium sulfate, which can increase the life of the coagulating bath.

Once the fibers have been removed, the saline solution can be recirculated and used again. However, it is It is important that the salt concentration is maintained, especially when the salt is chemical Reaction related to the starch dispersion at the time of introduction is exhausted. With those Starch dispersions that do not contain any alkalis are hardly difficult to recirculate, if the solids content of the salt is maintained but if alkaline starch dispersions are used, chemical reactions occur with the coagulating solution. For example, if If ammonium sulfate is used, the reaction leads to the formation of gaseous ammonia and sodium sulfate The recirculation in such a system can be extended by removing the ammonia in one Acid scrubber is recovered and returned to the system as ammonium sulfate. That generated Sodium sulfate can be used in the coagulating bath as part of the salt mixture until those mentioned Tolerance limits can be achieved, or can be used as raw material for other pulp or paper making purposes can be used, for example, as a salt cake in the manufacture of Kraft pulp.

Starch fibers can be made at any temperature at which the starch dispersion can be used. In general, the coagulating bath is maintained at about room temperature (20 ^° C.) during the manufacture of the fibers, although temperatures up to about 70 ^° C. can also be used. Such higher temperatures can be desirable under certain conditions because they increase the solubility of the salt in the coagulating bath, so that more concentrated solutions result. When starch fibers from corn are to be produced with the use of monobasic Ainmoniumphosphat as a coagulating agent, it is desirable to increase the temperature of the bath to provide a concentration of the salt (to obtain approximately 40% the Sätligungsgrenze for monobasic ammonium phosphate at 2O ⁰ C is 28% ).
For the production of the starch fibers, the slark dispersion is introduced continuously or in droplets in the form of a thread-like flow into the moving coagulating salt solution. This addition can be top or bottom into the saline solution using any known method.

The dispersion can be extruded through an apparatus containing at least one orifice, for example by a spinneret, an injector or any other supply line suitable for injection. Optional the dispersion can be transferred under positive pressure from a conduit into a surrounding closed area having a number of openings, for example a concentric one Line containing the moving coagulating solution. Numerous variations of this Process are possible, and the fibers can also be made using a continuous or discontinuous Process are produced.

In performing any of these methods, the aqueous coagulating solution is agitated when the Starch dispersion is introduced. The direction of flow of the two currents can also be related to this will be able to control the length and diameter or width of the fibers. When the saline solution is in a Moved direction, which coincides substantially with the flow of the starch dispersion, can be relatively round fibers are formed. When the starch dispersion is at an angle of about 90 ° too In the direction of flow of the saline solution, relatively flatter fibers are formed. In general

4Q openings of 10-500 μm diameter are preferred in order to produce fibers of the size required here. Therefore, starch fibers produced according to the invention have diameters (widths) of 10-500 μm and generally have lengths between about 0.1 and 3.0 mm if they are to be used in papermaking instead of conventional cellulose pulps. Longer fibers can be used for the production of non-woven webs such as fiber fleece.

The length, cross-section and configuration of the fibers depend on a number of parameters in addition to those already mentioned. Such additional parameters are the viscosity and the solids content the starch dispersion and the special components in the coagulating solution and / or the starch dispersion, as well as the relative viscosities, soft additional factors in connection with Parameters of the type already described can be used, namely the dimensions of the ones to be produced Control fibers. Other methods of coagulation known per se (US-PS 29 02 336) are used if this process ensures that the fibers produced have a have sufficient insensitivity to water in papermaking.

The resulting aqueous slurry or suspension of starch fibers can be directly related by introducing it into the pulp flow.

9 ΙΟ

In order to produce fibers together and a fiber quality that enables starch hydration. It is To enable paper web in papermaking. the mechanical treatment of the pulp during the When using this embodiment, it is in suspension in water, through which the particularly good It is generally preferred to first use the fibers for fat permeability to be achieved. The fibers become too Removing coagulating salt prior to introduction> puffed up to a near gelatinous state, of the slurry in the paper making process in question - If paper is made from hydrated fibers, washing stage. Optionally, the fibers in will form a dense non-porous layer on the screen a dry state can be obtained by being trained. The resulting layer is for fat and oil sine separation with the help of a sieve or an impermeable, because it consists of almost continuous, very corresponding establishment takes place. Preferably io well hydrated cellulose is made. To get the cellulose in however then bringing the fibers back into a well hydrated form is one non-aqueous solvents such as methanol, ethanol. considerable amount of energy required. Manufacturer isopropanol. Acetone slurried. in which the fibers of glassine paper must be their starting material are not soluble. The fibers are then, for example, or the se increase the number of treatment stages through which separated and dried. Other methods of how the starting material is passed through. If that Centrifuge. Dry by relaxation or a source material is hydrated and placed on the sieve Spray drying can also be applied to remove the drainage is very slow Water can be used. After drying will be in front of you. Therefore the working speed the fibers were again placed in a waofigci medium and ^ dcrsri; gcr paper machines s'jf 45 - 150. per minute then have a very good dispersibility, which is limited to a certain extent by the while maintaining their discrete discontinuous basis weight of the paper depends. The temperature of the Structure. Alternatively, the fibers from the starting material can be increased with steam To accelerate the dewatering on the sieve, for example by means of filtration, far away. washed and in water up to about 50% 25 attempts by manufacturers of glassine paper. by Solids content are brought to unite the drainage as "wet plates" cationic polyelectrolytes to be fed to further use. better, resulted in comparatively little benefit.

The starch used can also be chemically treated. By flocculating the fibers, the dewatering can be improved in order to improve the properties of the fibers, but this can influence pores or the formation of the colloidal 30, which increases the impermeability for dispersion favor. Alternatively, the fat and oil of the finished product can be deteriorated.
Starch fibers are treated after their training. In testing the invention it was found to cause certain functional properties. that with a combination of starch fibers with For example, the starch with the help of a cellulose fibers. which are less chemically treated than in the known process aminoethylation in order to achieve a rapid dispersibility in the starch for the production of glassine paper ground for 35 ren, the resulting mixture to achieve a considerable dispersion. Such a treatment leads to a higher degree of beating, and the dehydration also leads to the production of fibers which, when used at lower temperatures, can be cationic in about> / j the time in an aqueous medium, which usually have a previously used charge. Furthermore, a strength related to 40 higher temperatures can be used. Further, modified to contain a higher proportion of wet end anionic solids after grouping, so that it is stable in dispersion, pressing as well as improved drying efficiency and after regeneration to produce degrees relative to known methods leads to the production of fibers which have anionic properties. can be achieved by glassine paper. The resulting fibers can also be modified after their production 45. Properties of paper produced according to the process according to the invention are to achieve a higher internal shaft. For example, an improved strength (strength in the Z direction). improved anionic functionality can be achieved by bleaching the impermeability to oil and increased resistance to fibers after precipitation if this is done against the passage of air compared to not under conditions so extreme that the glassine paper known in the art. It can be seen that the fibers are thereby destroyed. The properties of reducing requirements with regard to the fibers can also lead to significant energy savings of modified and unmodified starches or grades through the use of mixed and cellulose processing, since the temperature of the fiber mixture does not have to be increased through the addition of other functional materials in order to be controlled, For example, with the help of poly- 55 to achieve a satisfactory drainage time, as acrylic acid does, in order to achieve the desired special properties in known processes for the production of pergae. minpaper is the case '

One of the advantages of the invention is also related to it being able to starch fibers on the other hand

see improved paper products becoming more diverse in making more porous sheets, soft |

Way to be produced on the basis of the properties, 60 properties in the case of filter paper or in the case of absorbent |

the either specific properties of the starch fiber paper grades is of interest in known |

The process itself or the properties caused by the process leads to a reduced level of treatment -

are. This is particularly important in the development of cellulose for a better formation of this

Production of special paper qualities such as property which advantage, however, only at cost

Glassine paper and filter paper, which are obtained when using a weaker web strength

known procedures may require special treatment. The incorporation of ^ strong fibers with the help of the

require. The method according to the invention enables in connection

Glassine paper is made from pulps in which the cellulose creates a more porous sheet structure

while maintaining, and often even improving, the desired strength.

It is also possible with the help of the method according to the invention, certain hydrocolloids in the Bring dispersing medium and the hydrocolloicle together with the starch to extrude to produce starch · hydrocarbon fibers, which in more advantageous Way can be used for papermaking. To make <? Crazy Fiber Composition, it is only necessary that the hydrocolloids (in small amounts of less than 50% of the total solids weight) together with the Slärk share placed in a state of colloidal dispersion prior to contact with the coagulating bath will. That is why it is important for water-soluble hydrocolloids such as polyvinyl alcohol, carboxymethyl cellulose, Hydroxyethyl cellulose only required to add the hydrocolloids to the water in which the starch is dispersed. In the case of other hydrocolloids such as casein, caustic alkalis must be added to the dispersion to form the required colloidal dispersion.

Even water-insoluble additives can be mixed uniformly into the starch dispersion, to be encapsulated in the resulting starch fiber. Additives insoluble in water such as pigments, Metal powder. Latex, oil. Plasticizers, microspheres (glass spheres, foamed silica or other low density materials in blown or unblown form) can therefore be used in starch fibers be included according to the invention. In a corresponding manner, water-insoluble synthetic Polymers or lances such as polyvinyl acetate, polyacrylonitrile, polystyrene embedded in the fibers will. Furthermore, the density of the starch fibers can be adjusted by embedding air or other gases in the Starch dispersion can be changed before entering the coagulating bath.

Furthermore, certain water-soluble solid additives can also be used together with the starch fibers be extruded. In such cases the additives are dissolved in the aqueous starch solution and the coagulating bath used to form the starch fibers is based on the addition of a sufficient one Set the amount of a compatible salt. which enables the additive to precipitate For example, a commercially available resin size can be added to the starch dispersion and converted into a coagulating one Bath can be extruded, which the functionally starch-coagulating salt together with a sufficient Contains aluminum sulphate to precipitate the resin, so that fibers made from starch-aluminum $ inat can be produced.

The water insolubility of starch fibers according to the invention can furthermore be achieved by the incorporation of conventional Crosslinking agents are improved, for example of urea-formaldehyde, glyoxal, urea-melamine-formaldehyde, crosslinked polyimide-epichlorohydrin resins be embedded. These crosslinking agents can be used prior to extrusion or the starch dispersion later added to the starch fibers.

The specially selected additive as well as that used in the exemplary embodiments described above The amount depends on the desired properties of the fibers. Pigmented fibers exhibit improved opacity and can be incorporated into the fibrous web by known methods in comparison to the simple addition of pigment to a paper starting material to achieve an overall improved pigment retention. A reduction in flammability can be obtained by adding polyvinyl chloride powder, antimony trioxide or other fire retardant for a substrate Chemicals are added to the starch fibers. Starch fibers containing microspheres can be used in Paper webs can be embedded with a large retention capacity. The retention of such beads enables the production of bulky printing paper and lightweight webs in the Compared to cellulose webs of comparable weight. In known microspheres containing The presence of the microspheres between the fibers has a releasing effect on the webs Fibers, so that the paper webs occupy a low strength.

In contrast, paper webs according to the invention have excellent strength because the Kiitrelchen are embedded in the starch fibers so that globule delivery is kept to a minimum. The density of the starch fibers and des The resulting paper can also be obtained by embedding air or other gases in the starch dispersion be changed before entering the coagulating bath.

By using fibers with embedded additive, it is possible, not just a new process to embed additives in paper, but also create new effects in the paper itself cause. In certain paper machines, the final web may be compressed from individual ones Layers exist. Such machines can be used as cylinder machines or as Fourdrinier machines a second or a plurality of reversing chambers. With machines of this type usually find lower quality fibers for the inner layers and quality pulp for the top one Location usage. By using pigmented starch fibers in the top layer, paper webs which have the surface properties of coated paperboard, as a result is coated paperboard via a wet end process due to the high concentration of starch and Pigment produced on the substrate surface. Optionally, special decorative paper grades can be used with differently colored pages can be produced. Dyed fibers can come with different colors and fed to two different reversing chambers or head boxes. paper with different coloring on both sides, which is produced by known processes, requires against it the use of surface treatments in manufacturing.

An advantage of using water-insoluble synthetic polymers incorporated into the starch fibers are embedded, it can be seen that a high retention capacity in paper or paper-like Sheets of synthetic fibers (such as rayon, acrylic, polyester, nylon or polypropylene fibers) are created Most of these fibers have a very low surface charge, so that their retention capacity is in commonly used latex binder systems is relatively poor, in which a precipitation and fiber deposition processes are used. Such poor retention can result in a poor binding efficiency and lead to problems with foam as well as with sticking and accumulation

of polymers in the system. Starch fibers with resin embedding ensure effective Retention and result in the desired properties of the paper produced «:.

Another feature of the invention is that the starch fibers can also be used in the manufacture of dry-laid, non-woven webs from synthetic fibers. In such applications, a web using air as the medium for applying the fibers to a moving screen is used. Because the synthetic fibers are not hydrated, binding is prevented and the resulting structures are relatively weak and soft. In order to cause the webs to stick together, it is therefore necessary to spray a binding agent onto their surface. According to the invention it is possible to mix dry starch fibers with the synthetic fibers. Such a method is particularly bsi weribsren w2 ^CT _t apwphtpn Opgenständtn not required because the biological decomposability tidr starch fibers is better than previously used bonding agents for synthetic fibers. Fibers with a particularly high amylopectin content are preferred as binders. It should be noted that the starch fibers can remain in the finished, nonwoven web or, if desired, can also be removed. For example, if the starch fibers are to be removed from a ceramic sheet, normal incineration conditions are sufficient to remove the starch fibers therefrom.

Starch fibers, with or without fillers, can be used successfully to manufacture from just starch existing paper, or in connection with all types of cellulose or other materials existing fibers. Usable fibers made of hardwood or softwood are, for example bleached or unbleached sulfate cellulose. bleached or unbleached sulphite cellulose, bleached or unbleached soda cellulose. neutral sulfite cellulose, semi-chemical wood pulp, chemical Wood pulp cellulose or combinations of such fibers. Among these names are wood pulp fibers to be provided, which are produced by a large number of processes known per se in the paper industry can be. Synthetic fibers made from viscose rayon or regenerated cellulose can also be used as well as waste paper. In a corresponding manner, ceramic fibers, glass fibers, or asbestos other inorganic fibrous materials are used in connection with starch fibers according to the invention turn around.

Because of the insensitivity to water used here Starch fibers result in a good dispersion of the fibers to form stable dispersions without the addition of surfactants can be used in conventional paper-making processes can. Therefore, the fibers can be used in papermaking processes and associated machinery without Modifications of the procedural conditions a can be used. Therefore, fibers can use the grinder or A mixing vat can be added to the head box on the sieve of a Fourdrinier machine to be applied ojid from there the web can be too the wet press by drying rollers and calendar rollers and without significant changes to the normal operation of the machines used in manufacture from cellulose paper. When paper is made entirely from starch fibers, it may be desirable to place the web between nylon screens or to vacuum it in the dryer, to prevent the fibers from sticking in the dryer.

Furthermore, the manufacturing processes for the paper can be integrated with the manufacture of starch fibers by using the slurry which contains the fibers just precipitated. It is also possible shaped objects directly from diel; rt \ pulp in molds to produce.

The specific type of starch used and the amount of starch fiber to be added depends on the desired one Paper quality. It has been found that selection of an appropriate type of starch enables it. properties of paper, etc., which used to be achieved only by hydration and fibrillation of wood pulp on various Release levels could be achieved. In particular, it has hitherto been less bleached to manufacture Beschirhtiingsnanpe according to the Kraft method required, lightly pulp (650 ml CSF) for rapid water removal while maintaining a to ensure high process speed. The extent of the work-up is also determined by the internal adhesive strength of the manufactured product is determined. The addition of starch fibers enables one Rapid water removal and maintenance of the working speed are also guaranteed however, the development of internal adhesive strength.

Glassine paper is often made from pulp that has been largely recycled (less than 50 ml CSF). On the other hand, it has been found that glassine paper or the like paper grades are reduced of cellulose processing can be produced by half if an amount as low as 15% Starch fiber is added. For paper grades for which there is still a low level of opacity and Porosity is required, find preferably larger ones Amounts of starch fiber used, i.e. about 50% or more.

A paper containing starch fibers can according to the invention together with conventionally related ones internal additives such as glue, additives for wet or dry strength can be produced. It can also a surface treatment per se b;.; annter type are carried out by applying a top coat Spray on or saturation.

Such types of paper containing starch fibers can be reprocessed into pulp and recycled will. The ability of the starch fibers themselves to pickle their fiber integrity in the event of re-pulp formation. is retained by the type of starch fibers (a higher amylose content of the starch favors the re-pulp production) as well as influenced by the conditions used during re-pulp production given are. The less basic chemicals and higher temperatures when re-pulping are used, the more conveniently a recirculation of the starch fibers can be carried out.

Using the following special examples the invention is to be explained in more detail, for example. In the following examples, all relate Component information on weight, unless otherwise noted

Example I.

A slurry was made by mixing natural unmodified starch made from 70% amylose

and 30% amylopectin with 5% by weight of solid starch produced, after which a 25% sodium hydroxide solution was added, sufficient to produce 40% causticity the starch on a dry basis. This mixture was stirred until the starch granules were dispersed was achieved.

The resulting dispersion was introduced at a pressure of 0.7 N / cm ² into a stirred, coagulating bath of 28% ammonium sulfate through a multi-hole nozzle with 100 openings, each of which had a diameter of 70.2 μm. The angle of entry to the moving saline solution was 90 °. The resulting fibers were collected on a wire screen, washed to remove salt and washed

Table I.

collected again The fibers had an average diameter of 75 μm, an average Length of about 4 mm and an eventual solids content of 23.5% by weight.

A number of handsheets were made using a mold with varying amounts of bleached softwood pulps (BSWK) in combination with fibers produced in this way. The leaflets were dried on the dryer at a Troranel temperature of 121 ° C and then for 24 hours aftertreated at a temperature of 22 ° C and 55% relative humidity

Table I contains related manufacturing and experimental data.

Fiber blend
BSWK

Slark fibers

Basis weight
(g / m)

Sheffield porosity ² )

Strength in
Z direction ³ )

100 0 78.1 544 218 596 90 10 82.6 540 192 630 75 25th 80.4 475 74 846 50 50 77.9 367 28 1050 + 25th 75 77.1 250 16 1050 +

Measurement of the water runoff from the pulp through a wire screen. Unmilled pulps have a high clearance level

(CFS) relative to low release level of well-milled pulps. TAPPI experimental test T227-M-58.
² ) In this experiment, the air resistance of paper is measured. It measures the volume of air that passes through a specific unit of area at a given pressure in a certain time. The higher the trial value.

the more porous the sheet is. A ring with an inner diameter of 7.62 cm was used. The specified values

are dimensionless.
^} ) The Z tensile strength was measured with a Scott Tesl device. This test method uses the average force

given in juules per m ¹ .

The experimental results contained in the table show that the presence of increasing amounts of such starch fibers made in a 5% solids dispersion, the holding power for Water in the fiber mixture expands and results in the production of paper sheets that are less porous and have a higher Z-strength than paper made from 100% cellulose.

Example 2

The starch fibers were made using the materials of the procedure according to Example I, however, after the final wash the fibers were dispersed in ethanol, collected and then dried. The fibers were then combined with cellulose and layers produced as in Example 1 The tests carried out with it showed that the dried fibers Have properties comparable to those found in the moist fibrous products in Example 1 were achieved.

Example 3

The starch fibers were made using the materials and processes mentioned in Example 1. However, in this case, the concentration of starch solids in the starch solution was increased to 20% and the final solids content in the fibers was 38%. The sheets were as in Example 1 manufactured and measured. The results are given in Table II.

Table Il

Fiber blend
BSWK

Starch fibers

Basis weight
(g / m ² )

CFS
(ml)

porosity

/ -Fixing wedge

100 0 86.2 505 158 538 90 10 82.9 545 333 527 75 25th 82.9 595 1.215 565 50 50 79.7 676 8.645 647 25th 75 79.7 814 50.496 1035 + 230 225/253

As can be seen from Table II, the use of starch fibers resulted from a dispersion with a higher solids content, an increase in the clearance level of the entry for Water (CFS), as well as more porous sheets with greater porosity and Z-strength than 100% sheets Cellulose. Note that this percentage of starch solids has values of the degree of release and porosity results, which clearly differ from the values in example 1

differ, with 5% starch solids used to make the fibers. This comparison shows the adaptability of the method according to the invention for the production of a variety of Properties in the final paper product, e.g. B. the required porosity for glassine paper in Compared to filter paper. On the other hand, in both Example 1 and Example 3, the strength of the paper was increased increased by the use of starch fibers

Example 4

Tests carried out on starch fibers from a dispersion with 20% leaves showed that

Starch as in Example 3, but with the exception of 15, the dried fibers gave properties that

produced that after washing are again comparable to those with moist

The suspension in ethanol was carried out as soon as a fiber product in Example 3 was obtained Recovery and drying. At established

Example 5

This example concerns the use of fibers made from different starch materials became. The starch fibers produced were combined with cellulose according to example i. Of the

Table III

Cellulose content was ground to a release rate of 645 ml (CFS) before mixing with the starch fibers and the basis weight of the layers was kept at 97.5 g / m ² .

Fiber blend

Starch material

Starch fibers

Tensile strength ¹ )

N / cm 'Mullen')

g / cm

/-Strength')

Folding test ''

100 0 - 10.1 4429.40 145 552

90 10 aminoethylated cereals 14.3 6679.26 903 1.210

70 30 the same 14.7 5624.64 1050+ 1.280

90 10 corn 15.2 6679.26 853 1.670

70 30 the same 14.1 5062.17 1050+ 1.125

90 10 unmodified grain 15.5 5484.G2 567 1.340

70 30 same 12.9 3445.09 1050+ 1.245

90 10 I lybrid grain with 70 "/ o amylose 16.5 5273.10 622 1.420

70 30 the same 16.5 4148.17 1050+ 1.390

90 10 Amylose 15.4 5413.71 683 1.4. "

70 30 same 16.5 4780.94 1050+ 1.395

') TAPPI procedure T4I14 -.Ss-66. by which the tensile strength is determined.

-) TAPPI procedure T403-ts-63. which determines the hydrostatic pressure required to tear the paper

is. if cm increasing pressure by a rubber diaphragm au ^r a circular area with a diameter of 3048 cm is applied. '(Test conditions as in example 1
⁴ ) T λΡΡΙ method T423M 50. which is used to determine the number of folds before breaks occur (test device

of the Massachusetts Institute of Technology).

As can be seen from Table III, an addition of all of the different starch fibers mentioned can be used strength properties of the paper compared to using paper with 100% Increase cellulose.

Example 6

This example relates to two methods of making sheets from 100% starch fibers.

Method A: 6 g of unmodified corn flake fiber was slurried in 1 liter of water. The fibers were agitated to produce a uniform mixture. A layer was produced using the Noble tind Wood mold with a 0.149 mm mesh wire screen. The resulting fibrous web was removed from the screen and blotter and compressed several times. There were three PreBvofgattge at 68.8 N / cm ² and three pressing processes at 175 N / cm ² while changing the drying felt

between pressing operations. The resulting solids content was 70%. The web was then placed between dryer felts and dried in a dryer at 120.1 ⁰ C. The resulting stiff and self-supporting paper-like product had a basis weight of 145 g / m ^2.

Method B: Starch fibers were treated as in Method A and the resulting web was subjected to two presses at 68.8 N / cm ² and then two presses at 138 N / cm ² with changing the drying felt between presses so that the resulting solids content Was 50%. The web was then placed between two nylon sieves and passed through the dryer at 120.1 ⁰ C. The resulting paper-like web had a basis weight of 145 g / m ² .

Example 7

There are layers prepared by the method of Example 1 with de * except that standard commercial

Table IV

borrowed unmodified refined glassine raw material with two degrees of release was combined with starch fibers from corn. The cellulose pulp was obtained from two refining points so that one part had a degree of release of 350 ml, while the fully refined part had a degree of release of 160 ml. There was an addition of starch fibers corresponding to a proportion of 20% and all layers were produced with a weight per unit area of 48.8 g / m ² . The layers then underwent a surface sizing in einsr press on a laboratory scale, which is provided with rubber rollers using a polyvinyl acetate solution with 1% solids content at 60 ° C, so that a 1 ⁰ Zoige recording of polyvinyl acetate was obtained. The layers then underwent an aftertreatment at a constant temperature of 20 ^° C. and an air humidity of 55% for 24 hours before carrying out tests to determine the turpentine resistance (TAPPI T454-ts-66).

The results of these experiments are shown in Table IV

Release;; wheel

proportion of

Starch fibers

Schichlform-
Drainage time Temperature of
of the initial
painterials (C) 21.3 see 24 19.9 see 24 62.1 see 60 Example 8

Terpenlin trial

350 ml
35OmI
160 ml

100

100

20th

The use of starch bevel η in combination with partially refined or reconditioned pulp increased the turpentine resistance of that pulp alone and matched the resistance of fully prepared glassine starting material. Furthermore, the reduction in work-up reduced the drain time by a factor of nearly 3 at considerably lower temperatures. When using the method according to the invention can therefore a dewatering in about 20 seconds at a temperature of 24 ° C without loss of desirable properties occur while it is necessary for a known starting material, to raise the temperature to about 60 ⁰ C to a dewatering in 62 seconds to achieve. The improved dewatering enables higher operating speeds of the machine and an improvement in the efficiency of production while achieving considerable energy savings due to the lower treatment temperature.

855 see
1800+ see 1800+ see

This example concerns the improvement of properties brought about by the combination of cellulose pulp can be achieved with starch fibers containing microspheres of polymeric material.

Starch fibers were produced according to Example 1, but with the starch dispersion prior to fiber formation 8.5% microspheres were entered. The fibers were then combined in layers with Cellulosic pulp incorporated using the procedure in Example 1. In all cases the was Clearance level 730 m! for the proportion of cellulose. Table V shows test results. For comparison purposes, samples were also prepared to which the Microspheres were added directly into the paper pulp as in known methods.

Table V Strength-
fibers % Beads in the
layer Surfaces
weight Thick
measurement ¹ ) Stiff
speed ² ! / • heMig-
keit'i Fiber blend 0 added 0 (g / m ² 1 (I χ in 'cm ι BSWK 0 0 0 97.6 18.79 3.7 111 100 0 0 0.86 130.1 24.38 6.3 137 100 1.8 97.6 24.39 6.6 103 100

continuation

! •.! • .ormi-.chiing Sliirkc- ".. Kiigclchcn in dor
layer l-'liiclicn
w ic hi USWK 0 / iigo- <cl / t 1.0 Ig / nr ι 100 5 2.0 0.43 97.6 95 10 0.43 0.86 97.6 90 15th 0.86 1.29 97.6 85 1.29 97.6 ') Paper thickness.
² ) TAPPI method T451-M-60.
³ ) As in example 1.

mevding ¹ 1
(I * Hi'crni

Z-l-c, Hg-

25.40
23.11
26.16
28.45

7.1
5.0
6.3
7.5

90
168
206
237

As can be seen from Table V, in each of the cases concerned, the addition of microspheres leads to a significant improvement in the thickness and stiffness of the paper. In this context, the addition of microspheres made it possible to achieve the thickness and rigidity corresponding to a basis weight of 130 g / m ^{2 with a basis weight of only 97.6 g / m 2.} The weight saving means a significant advantage both in terms of the amount of fiber required and in terms of subsequent costs, such as postage costs.

When the other properties of the sheets containing microspheres were compared, it was found that that the retention level of the externally added beads is about 50% of that initially added Amount, while the degree of retention when added to the encapsulated fibers is almost 100% fraud. Furthermore, there was a decrease in strength and indications of uneveness Distribution of the globules (with a greater concentration on the felt side) in the case of external added beads, while these factors are not in the case of the starch-encapsulated beads occurred. The improvements in thickness and rigidity in the known external addition of the Therefore, beading is only at the expense of reducing the internal bond strength of the paper achieved, while when installing rJer beads in the Starch fibers increase the retention of the beads in the sheet while increasing the internal adhesive strength in addition to the desired improvement in stiffness and thickness can be achieved.

Example 9

This example concerns the results obtained with the addition of clay in papermaking. It layers were prepared by procedures similar to that in Example 1. The layers became like this prepared that a second quality of clay for coatings in the final sheet during the Manufacturing was incorporated. The clay was built into the layers in different ways:

1) by the usual slurry of the pigment in the pulp fibers,

2) by incorporating starch fibers, which were produced according to Example 1, but 80% clay and Contained 20% starch, or

3) by using a combination of 1) and 2). In all cases the basis weight was 97.6 g / m ² . The physical and optical properties of the paper are given in Table VI.

Table VI *. volume "'. TiC) ₂ Starch fibers % Clay Lichtdi'rch- tensile strenght Z-solid 0 0 0 casual) keit'l Usual addition 12.8 0 "'" Strength 0 N / cm ² 0 0 0 19.8 85.9 9.7 302 * ·· C ellulose 6.8 0 0 19.8 92.0 6.2 113 100 ü 4.5 5.0 18.7 88.9 13.6 351 87.2 5.0 90.5 8.6 256 75.2 4.7 94.1 8.4 233 68.4 72.1

') TA t'f'NVerfahren T425-m-60, expressed in% and defined as one hundred times the ratio of the diffuse reflectivity of a sample below which a blank sheet with not more than 0.005 reflectivity of the same sample litgt. below which a white body with an absolute reflectivity of 0.89 lies. The higher the value, the more opaque the paper is.

² ) Defined in example 5.

³ ) In example 1 definVrl.

As can be seen from Table VI, the incorporation of pigment into the starch fibers allows higher Pigment content and better wedge properties compared to known methods for installing Pigments. When 12.8% clay is added to cellulose pulp by known methods, the Tensile strength and the Z-strength reduced. Conversely, if 19.8% clay in the form of encapsulated Starch fibers (total addition of 24.8%) are added, the tensile strength and the Z-strength are improved. It can also be seen that the reduction in light transmission through use of clay-containing fibers by the external addition of a small amount of clay or titanium dioxide can be compensated.

Example IO

This exemplary embodiment serves to explain the improved retention of the starch fibers in the Process according to the crust. Bleached softwood cellulose of 500 ml (CFS) grind and divided into three portions. A stake became sound of Coating Grade No. 2 was added and the resulting mixture was stirred until the pigment was uniform was distributed in the pulp fibers. Another portion was treated in the same way, with the exception that that a water-soluble acid salt of an aminoalkyl ester of a carboxylic acid copolymer as a retention aid was added. The remaining part of the pulp was starch fibers with clay contained therein (50% Starch and 50% clay) was added and the fiber mixture was stirred until even distribution was achieved. Similar to the method in Example 1, layers were produced which were produced according to the Clay content and percentage restraint were examined. The results are in Table VII included.

Table VII volume Retirement
functional
middle % Reten
tion of
volume Fiber blend
BSWK strength
fibers
(50% clay) 10
10
0 0
0.02%
0 11
35
97 90 0
90 0
80 20

As can be seen from Table VIl, the retention capacity is for clay greatest when the clay is in the starch fibers in the method according to the invention is embedded.

Example 11

The following example serves to explain the binding properties of starch fibers during manufacture multilayer webs.

Two-layer nonwovens were made from bleached softwood cellulose, which cellulose was ground to a release level of 500 ml. To produce an eventual basis weight of 146 g / m ^2, two layers were (each with about 73 g / m ²⁾ were prepared and Naess pressed together prior to drying in the dryer at 121 ⁰ C. The comparison paper contained 100% cellulose in both layers, while in the test paper 20% of the cellulose in the upper layer was replaced by starch fibers. the

The adhesion between the layers was tested in a Scott tester and the test results are included in Table VIII.

Table VIII

Fiber blend Lower Sch'cht

Z strength Upper layer

30th

35

100% cellulose 100% cellulose 119.7 100% cellulose 80% cellulose 197.4 and 20% Starch fibers

40 As can be seen from Table VIII, the Starch fibers increase the adhesive strength between the layers of the paper sheet.

Example 12

This example is used to explain the production of paper that contains various additives, which are brought in through the addition of starch fibers containing the encapsulated additives. As in Example 8, additives were embedded in the starch fibers and it became paper sheets made with a given percentage of the starch fibers according to Table IX

Table IX

Additive

% Additive
in starch fibers

% Addition of
Starch fibers
in the pulp

CaCO,

Aluminum powder

Alkylene succinic anhydride as a sizing agent

Reinforced rosin as a sizing agent

A 1: 1 mixture of antimony trioxide and one Vinyichiorid homopolymer fire retardant)

Tris-dichloropropyl phosphate (fire retardant)

25th 20th 25th 20th 25th 20th 25th 20th 5 10 5 10 50 50

40

230 225/253

In all cases the additives were high in the final paper product maintained.

Example 13

This example serves to explain the use of starch fibers to accommodate latex bandages iodine in a non-woven synthetic web Fibers. A dispersion of rayon fibers (0.635 cm, 1.5 denier) and polyester fibers (0.635 cm, 1.5 denier) were made

10

made with 0.1% solids in sealed containers. A test with 100% slark fibers and a product with starch fibers containing 20 percent by weight of latex were also made. Vinyl acetate-bulyl acrylate copolymers were added as binders in such amounts that the final fiber mixture contained 25%, based on the starch fibers. Sheets of paper with a basis weight of 65 g / m ² according to the method in Example I were produced. The paper sheets were tested to determine tensile strength. The results are given in Table X.

Table X

Sliirkefiber content

Binding content Synthetic fibers Granted wedge ¹ ) (N / cm ² ) _ Rayon *) - polyester *) 25% Rayon 6.9 25% polyester 2.0 25% Rayon 9.6 25% polyester 1.3

none (comparison)

none (comparison)

100% strength

100% strength

80% strength - 20% latex

80% strength - 20% latex

*) The paper sheet no / ur measurement of the tensile strength possessed sufficient ^l: cstigkcil ') defined in Example 3

As can be seen from Table X, fiber layers made from starch fibers and from starch-latex fibers as binders had a significantly better tensile strength. In contrast, the fiber layers made of 100% synthetic fibers produced for comparison had only such a low tensile strength that a test could not be carried out. The latex material used increased the tensile strength of the fiber layer made of rayon fibers, but decreased the tensile strength of the fiber layer made of polyester fibers compared to the fiber layer with 100% starch fibers. It follows that the appropriate latex material must be as chosen for the treated synthetic fibers.

Example 14

This example serves to illustrate the use of starch fibers as a binder with ceramic Fibers. The example also shows that binders in the form of starch fibers are used to replicate the fiber layer can be removed to produce a 100% ceramic fiber layer.

A 3% ceramic fiber slurry was prepared in a Waring blender and stirred for one minute after adding 0.2% NaOH (dry basis based on the weight of the fibers) as a dispersant. The fiber mixture was then placed in a container, on which a stirrer was provided, and a predetermined amount of starch fiber was added from a mixture containing 1% solids. After stirring the mixture for 5 minutes, layers of 407 g / m ^{2 were produced} on said device. For comparison, a ceramic layer was made without the addition of starch fiber material. Table XI shows the tests carried out.

Table Xl Hächcnguwichl
(g / m ^?; Tensile strength ¹ )
(N / cm ^J ) Slurkcfiiscr 407.5
407.5
407.5 *)
0.034
0.2 0
5%
10%

*) The layer hesali insufficient oil ^; estigkeil / ur Carrying out a measurement.
') Defined in example 5.

The layers containing starch fibers were then placed in an oven in which incineration the starch fibers and a fusion of the ceramic fibers took place. In that way one could be very good ceramic layer can be produced.

Example 15

Two layers with 10% TiO _{2 of} the final basis weight of about 145 g / m ² were produced.In the comparison layer, ΤΪΟ2 was added in the usual way by dispersing the pigment with the unbleached fibers of the upper layer added in sufficient quantity to the upper layer to achieve a content of 10% "2 at the final basis weight.

The final product had two layers, each of which was made separately on the aforesaid device at about 724 g / m ² , removed from the screen and pressed together in the wet state at 138 N / cm ^2. The layers were then dried in the dryer at 121 ^° C. for brightness measurements

were carried out on the upper side of the layer according to TAPPi R452-M-58, whereby the table XIl indicated results.

Table XII

Brightness of the
upper layer

Comparison layer
Layer of starch fiber

26.2
30.1

The results contained in Table XII show that layers of starch fibers with embedded TiCb had better qualities than those; which were produced by known processes.

Example 16

According to the general procedure of Example 1, powdered potato starch was made (Country of origin Dakota) for the production of hahd bows a quantity of 1000 g of a dispersion made with 10% potato starch with 18% NaOH. she got then in a saturated ammonium sulphide solution with a pressure of 1.38 bar from a spinning head with 100

ίο Woven openings with a diameter of 70 µm.

The obtained fibers were left to stand in the salt overnight, then washed and mixed redispersedi The fibers remained insensitive to water, retained their cohesion and left

easily absorbed in the cellulose pulp, which is called Cellulose portion of each hand sheet was used and obtained from repasted standard blotting paper so that the handsheets would be preserved.

The handbows had equally good properties witf they are listed in Example 1.

Claims (10)

Patent claims: 1. Process for the production of paper, cardboard or paperboard, in which an aqueous slurry from a fibrous pulp material is applied to a sieve to by dewatering a to form solidified fiber layer, from which the finished fiber after pressing and drying Paper product is made, characterized in that starch in an amount of 1 - 100 percent by weight of the pulp in the form of water-insensitive starch fibers 10-500 μm diameter is added, and that the fibers by extruding a filamentary stream from a colloidal dispersion of Starch with 5-40 weight percent solids in a moving coagulating bath consisting of a aqueous solution of a coagulating salt ammonium sulfate, ammonium sulfamate, monobasic Ammonium phosphate, dibasic ammonium phosphate and mixtures thereof, the solution comprising the coagulating salt in one Contains amount that is at least sufficient to coagulate the starch. 2. The method according to claim 1, characterized in that made of corn starch or corn starch manufactured starch fibers are used. 3. The method according to claim 1, characterized in that that starch fibers made from starch with a high amylose content are used. 4. The method according to claim 1, characterized in that from cationically modified starch manufactured starch fibers are used. 5. The method according to claim 1 or 4, characterized in that ether or ester derivatives Starch fibers made from starch are used. 6. The method according to any one of claims 1 to 5, characterized in that starch fibers in one Lengths of 0.1 to 3.0 mm can be used. 7. The method according to any one of the preceding claims, characterized in that the colloidal Starch dispersion a dispersed water-insoluble additive that contains starch in an amount replaced up to 80 wt .-%, is added. 8. The method according to any one of the preceding claims, characterized in that the colloidal Starch dispersion is a dispersed hydrocolloid in an amount less than 50% by weight of the Starch is added. 9. The method according to any one of claims 1 to 8, characterized in that the remaining fibrous Pulp material mainly wood cellulose is used. 10. The method according to any one of claims 1 to 8, characterized in that the remaining fibrous Puipematenal mainly polyester fibers, rayon fibers, ceramic fibers. Fiberglass and Asbestos fibers are used.