Paper of improved rigidity and bulk and method of its producing

FIELD: paper industry.

SUBSTANCE: paper with improved rigidity and bulk and method of its manufacturing may be used in pulp and paper industry and are intended for photocopier equipment. Paper comprises three-layer double-tee structure that forms a single web. It has central core layer manufactured mainly from cellulose, bulk of which is increased with the help of filler, such as hydrazine salt. Starch-based coating is applied on both sides of core layer, at the same time starch has high content of solid products. Coating forms three-layer paper having composite structure with outer layers of high strength that surround core of low density.

EFFECT: improved strength, rigidity and resistance to twisting of produced material.

32 cl, 2 dwg, 3 tbl, 3 ex

 

The technical field to which the invention relates

The present invention relates to the field of bumagomaraniem and, in particular, to the manufacture of substrates from paper. The present invention also relates to products made of a substrate according to the present invention, such as printing paper and products made of cardboard.

A related application

The present application claims priority on provisional patent application United States serial number 60/410,666, filed September 13, 2002.

The level of technology

Modern workers and home offices use a variety of paper products, including, but not limited to, varieties of paper for copying and duplicating equipment and cardboard, such as paper for writing, printing paper, copy paper and paper forms. Unfortunately, such products on the basis of paper and cardboard exhibit one or more disadvantages. For example, some of these products have a relatively low mass per unit area or are not sufficiently rigid in bending or wear-resistant in order to withstand the full cycle passing through the copier. Thus, in industry there is a continuing need in the production of paper for copying and duplicating equipment with a lower weight on a single the HQ area, but with the same, as now, by the properties of rigidity, in order to preserve the original materials and to be able to increase performance. Other important properties of paper for copying and duplicating equipment is tightening, there is a movement outside the plane, and hygroscopic extensibility, that is, the expansion and contraction of the paper when the relative humidity. Low twisting is required at the time of packaging paper in copiers and to the correct input. Low hygroscopic extensibility is required due to the fact that Curling is a function of the hygroscopic extensibility and distribution of the material in the sheet (see, for example, Carlsson, L.: A Study of Bending Properties of Paper and their Relation to Layered Structure, Doctoral thesis, Chalmers University of Technology, Department of Polymeric Materials, Gothenburg, Sweden, 1980, ISBN 91-7032-003-9). Hygroscopic extensibility and twisting are also a function of how bumagomaraniem, in particular of the processes occurring during the drying of the fibrous web (see for example, Handbook of Physical Testing of Papers, 2ndEdition, Vol.1, Chapter 3, RR-117, ISBN 0-8247-0498-3 by T. Uesaka: Dimensional Stability and Environmental Effects on Paper Properties). The bending stiffness of paper Sbis a function of the elastic modulus E and thickness t, so that Sbproportional to Et3. This means that the most effective way to increase the gesture of the spine bending is to increase the thickness of the paper. However, the thickness, as a rule, should be kept within the specified limits. An even more effective way to increase the bending stiffness is the effect of creating a composite material that is durable dense outer layers and a core with a lower density. Mathematical expressions for the three-layer structure show that the effect of the composite structure creates a significantly higher bending stiffness in comparison with a homogeneous structure, if all other parameters are held constant (see for example, Handbook of Physical Testing of Paper, 2ndEdition, Vol.1, Chapter 5, RR-256, ISBN 0-8247-0498-3 by C. Fellers and L.A. Carlsson: Bending Stiffness, with Special Reference to Paperboard). This knowledge is limited to use in multilayer cardboard and printed paper, with a low weight per unit area, such as paper for copying and duplicating equipment (see, for example, Haggblom-Ahnger, U., 1998, Three-ply office paper, Doctoral thesis, Abo Akademi University, Turku, Finland, 1998).

Modern installations for the surface treatment of paper machines producing paper types for copying and duplicating equipment are usually installed for dosed sizing. These settings can cause the starch for surface treatment (and/or other reinforcing components) to other layers of the sheet. This technology is demonstrated in the published literature (see e.g. the measures Lipponen, J. et al.: Surface Sizing with Starch Solutions at High Solids Contents, 2002 Tappi Metered Size Press Forum, Orlando, FL, May 1-4, 2002, Tappi Press, 2002, ISBN 1-930657-91-9). The authors indicate a significant improvement of stiffness in bending, by applying the solution of starch in the plant for sizing, with 18% solids, compared with a lower content of solid foods (8, 12 and 15%).

There are also using the fill pressure setting for sizing (also called pools or baths)that are used everywhere. In this case, the possibility for applying solutions of starch in the outer layers is not the same as in plants for controlled sizing, because initially deeper penetration into the sheet in the installation, use the fill under pressure. However, the results presented in the literature, they say that the increase in the content of the solid products of starch may also provide less penetration with the ability to improve the rigidity in bending (see, for example, Bergh, N.-O.: Surface Treatment on Paper with Starch from the Viewpoint of Production Increase, XXI EUCEPA International Conference, Vol.2, Conferencias nos. 23 43, Torremolinos, Spain, p.547, 1984). There is, however, an opportunity to significantly improve the bending stiffness in comparison with the results reported in the literature, and to obtain other advantages, such as formulated above.

Accordingly, there is a need in the Ulu is the Chenin-based products paper and cardboard that reduce or eliminate one or more of these drawbacks, thus allowing for the production of varieties of cardboard and paper for copying and duplicating equipment with much lower mass per unit area, with higher productivity and, consequently, at lower production costs. Such an improvement would benefit from increased bulk canvas paper before applying the surface treatment (note the great influence of the thickness of the paper on its bending stiffness) in conjunction with solutions of starch with a high content of solid products, including a viscosity modifier and/or agents for cross-linking to increase the strength of the coating obtained by surface treatment, and to increase the binding of the compound to the surface of the applied layer. In addition, the present invention is the creation of these benefits in part one linen paper, thereby eliminating the costs associated with the additional equipment required for the paper, with many pulp layers.

The invention

Accordingly, the aim of the present invention is to provide a paper or paperboard having improved bulk and stiffness, having a three-layer, forming a single composite fabric structure c in rhym layer, the Central layer and the bottom layer, where the Central layer is a cellulosic core layer and the upper and lower layers have a basis of starch and are applied through a sizing coating layers, which cover the upper and lower surfaces of the Central layer, with minimal penetration into the Central layer, and penetration of the filler in the pulp and the core layer.

In addition, the aim of the present invention is to provide a paper or paperboard having improved bulk and stiffness, having a three-layer, forming a single fabric composite structure having a top layer, a Central layer and the bottom layer, in which the Central layer is a cellulosic core layer and the upper and lower layers have a basis of starch and are applied through a sizing coating layers, which cover the upper and lower surfaces of the Central layer, the top and bottom layers have a coating weight based on the starch, per unit area, within 2-10 grams per square meter, and a filler, penetrating into the cellulosic core layer.

In addition, the present invention is to provide a method for making paper or paperboard comprising the stage of creation of compositions containing pulp fibers and filler forming fibrous webs of the composition for the manufacture of paper, drying fiber fabric, with the formation of a dried leaf, by sizing the dried cloth with the solution for sizing with high strength, starch-based, with the formation of the upper and lower plating layers on the upper and lower side of the fiber fabric and drying the fiber fabric after processing through the ring, with the formation of three-layer, forming a single fabric material having a composite structure.

Other objectives, implementation options, features and advantages of the present invention will become clear, if the description of the preferred alternative implementation of the present invention to be read in conjunction with the accompanying drawings, which should be considered illustrative, but not limiting sense.

Brief description of drawings

Figure 1 is a schematic illustration of a three-layer paper according to the present invention obtained by increasing the bulk of the main sheet and use starch with a high content of solid foods containing viscosity modifier/fillers/agents for cross-linking.

Figure 2 is a schematic illustration of the method in a paper machine.

Detailed description

Paper 10 in accordance with the od of them from the embodiments of the present invention depicted in figure 1, the term "paper"as it is used here, includes not only paper and its production, but also other products like linen, such as cardboard, and their production. Flat cellulosic core layer 12 with filling is covered on both sides by obtained by ring coating 14 high strength starch-based. Cellulose fibers formed from compositions chemical wood pulp, having a mixture of fibers of hard wood and soft wood with additional fillers, such as precipitate of calcium carbonate or other fillers known in this field. Among the fibers can dispergirujutsja surface-active agents, retention agents, or other additives usually added to products on the basis of the paper. The ratio of fibers soft wood and hard wood in the framework of the present invention may vary. Ideally, the ratio of fibers of hard wood and soft wood is in the range between 3:1 and 10:1. However, there may be used other relationships hard wood/soft wood or other types of fibers, such as fibers from chemical pulp, such as sulphate and sulphite pulp, containing wood, or mechanical wood pulp, such as thermomechanical Dre the forest mass, chemi-thermomechanical wood pulp, refined wood pulp and wood pulp of crushed wood. Fiber can also be the basis of recycled fibers, optionally, from bleached fibrous mass, and mixtures thereof.

Cellulosic core layer 12 is a core of low density, in which the bulk is increased by the filler, thus achieved an increase in the thickness. The preferred implementation uses a filler, based on diamides salts, such as mono - and distearate of aminoethylethanolamine, commercially available as Reactopaque 100 (Omnova Solutions Inc., Performance Chemicals,1476 J.A. Cochran By-Pass, Chester, SC 29706, USA, supplied to the market and sold Ondeo Nalco Co., with headquarters in Ondeo Nalco Center, Naperville, IL 60563, USA), from about 0.025 to about 0.25 wt.% in relation to the mass of dry material. However, there may be used various chemical fillers known in this field, such as quaternionic imidazolin or microspheres, where the microspheres are made of a polymeric material selected from the group consisting of methyl methacrylate, ortho-chlorostyrene, priorto-chlorostyrene, polyvinylidenechloride, Acrylonitrile, vinylidenechloride, para-tert-butylstyrene, vinyl acetate, butyl acrylate, styrene, methacrylic acid, vinylbenzoic and the combination of the two or more compounds, above. The core layer 12 may contain other materials, such as surface-active agents, retention agents and fillers known in this field. The use of retention agents, as a rule, is preferred, if the filler used microspheres. In the preferred embodiment, using diamido salt-retaining agents are not required.

In a preferred embodiment, the layers 14 of the coating starch-based cover both surfaces of the core layer. Coating high density cover upper and lower surfaces of less dense pulp core with filler, creating the effect of a compound structure that represents a three-layer, constituting a single leaf paper product. In other embodiments, the implementation of only one side of the cellulosic core layer can be covered with the coating on the basis of starch by sizing. Coating high-strength form of solutions based on starch solid content of products within 6-20%, but preferably with a strong solution of starch, larger than normal paper, but still low enough to prevent excessive penetration of the coating into the core layers. Industrial embodiments of the present is about invention, as a rule, use the content of solids of about 6-12%. However, in other preferred embodiments, the implementation of high rigidity can be achieved with the help of the content of solids in the starch of about 18%.

The coating is absorbed into the cellulosic core layer to a minimum or does not penetrate at all. As a result, in pulp core starch can essentially be missing. Control of penetration is ideally achieved through coating by dosed sizing, so that the thickness of the outer film can be tracked with great accuracy. In preferred embodiments, the implementation of the ratio of the film thickness of the coating layers on the basis of starch to the thickness of the paper in General is in the range between 1:50 and 1:1,1. Levels of porosity paper also affect the penetration of the coating. Control of the thickness and penetration is the key to creating three separate adjacent layers that form the composite structure, having an outer coating of high strength, around a core of lower density.

The starch used in the coating may be any starch is commonly used in coating, preferably, gidroksietilirovanny starch, oxidized starch, cation-modified or enzyme converted starch from any ordinary what about the used source of starch, for example, potatoes, corn, wheat, rice or tapioca. The coating may also contain a viscosity modifier, agents for cross-linking and pigments, such as polyvinyl alcohols, ammonium zirconium carbonate, borate chemicals, glyoxal, melamine formaldehyde, crushed and precipitously calcium carbonate, clay, talc, TiO2and silicon oxide.

Upon completion, the weight of the paper 10 per unit area, usually located within 59-410 g/m2and the coating has a mass per unit area in the range between 2 and 10 g/m2.

Figure 2 depicts the scheme of what is one of the variants of the method used to retrieve the paper in figure 1. There are many types of paper machines with part of the grid/dry part. Thus, the present invention is not limited to a particular type of paper machine, such as that depicted in scheme 2.

The filler 20 is added to the composition while getting wet product in the wire section of the paper machine, where the composition may also contain additives, including fillers, retention additives, surfactants and other substances that are usually added to the composition for paper received in the wire section, which are known in this field. In this Varian is e implementation of the preferred filler is a product based on diamide salt (Reactopaque 100). However, other fillers can be used in the spirit of the present invention.

Wire section, in addition, includes the installation of 22 for cleaning, for machining wood pulp tank 32 machine headbox 24, which produces a wide spray composition on the wire section, with the formation of a fibrous fabric, paper, mesh section 26 having a movable sieve with an extremely small cells, the pressing section 28 and a drying section 34, containing a lot of back-up rolls, which are dried fibrous cloth and take it to the size press.

The coating on the basis of starch are mixed in the mixing tank 30. Used starch preferably is gidroksietilirovanny starch, oxidized starch, cation-modified or enzyme converted starch from any of the commonly used source of starch, such as potatoes, corn, wheat, rice or tapioca. In the present embodiment, the starch is cooked and add to the mixing tank with a viscosity modifier, agents for cross-linking and fillers, such as one or more of the following substances: polyvinyl alcohols, ammonium zirconium carbonate, borate chemicals, glyoxal, melamineformaldehyde, crushed and precipitiously calcium carbonates, clay, talc, TiO2and Oka is ü silicon. The starch may be cooked together with borate chemicals in a digester 38 for starch prior to entering the mixing tank. Mixed coating is transferred into the working tank size press, and then glue on canvas paper, coating one or both sides of the fabric. The coating on the basis of starch preferably has a solids content of products of starch within 6-20 wt.%. Coatings can be added simultaneously or sequentially in accordance with one of two techniques commonly used in industry. Thickness, weight, stiffness and resistance to twisting of the paper are basically the same for any technology.

Used processing through the ring preferably is a coating by means of a metered sizing. Due to the nature dosed sizing deposition of solid products of starch may be controlled and normirovanija. As a result, the penetration of the coating on the basis of starch in the pulp and the core layer is minimum, while maintaining the effect of the composite structure to a three-layer comprising a single fabric patterns. Moreover, I can use other kinds of sizing known in this field, such as coating using the ring by casting under pressure. In this case, who is very useful for applying solutions of starch in the outer layers is not the same as for facilities for dosed sizing, thanks initially to a deeper penetration into the sheet when filling under pressure.

Then covered with canvas paper is transferred for processing by sizing in the press section 36 of the paper machine, where the press section usually contains a lot of steam-heated rotating cylinder under the insulating casing near the path of the canvas paper for additional drying of the paper after sizing.

The obtained substrate paper demonstrates one or more improved properties compared to substrates that do not contain additives filler and/or subjected to sizing using starch with a high content of solid products, in conjunction with the viscosity modifier and/or agents for cross-linking. For example, some embodiments of the present invention, the substrate demonstrate the improved smoothness in Sheffield (TAPPI 538 om-88) on the grid side and the front side of the substrate, in contrast to the same substrate without the ingredients listed above, thus making it possible to lower calendering while maintaining bulk.

In addition, the paper demonstrates superior resistance to twisting of the property, the most important features of the final source is and varieties, designed for duplicating equipment, improved hygroscopic extensibility and improved resistance to bending according Lorentzon & Wettre. Other advantages of the present invention includes a closed list and/or improved ability to achieve the desired porosity of the paper, leading to higher numbers Gurley (TAPPI T460 om-96). This is advantageous as paper for copying and duplicating equipment is generally passed through the copying machine, using vacuum suction cups for lifting sheets.

The following non-limiting examples illustrate various additional aspects of the present invention. Unless otherwise indicated, temperatures are in degrees Celsius, weight of paper per unit area, grams per square meter, and the percentage of any additives to wood mass or humidity is relative to the total weight of material dried in the oven.

Example 1

A series of experiments carried out on a paper machine equipped with a device filled under pressure for sizing. Paper made from a mixture of about 9 parts of the wood of firm breeds of a tree and 1 part wood soft wood, and containing 19% filler (precipitating calcium carbonate). Standard glue AKD add as an internal glue and standard surface glue add in device for sizing with starch solution. Experience combined with the addition of Reactopaque 100 in a tank for pulp solid wood before refining. The speed of adding gradually reduced to 0.15%, and the coating of a sizing containing enzyme converted corn starch, replace with a coating containing starch with a higher content of solid foods (10% instead of the standard 8%), together with 5 parts, relative to the starch, glyoxal (Sequarez 755, Omnova Solutions Inc., SC, USA) and 25 parts, relative to the starch, powdered calcium carbonate (Omyafil OG, Omya, Inc., Alpharetta, GA, USA). One experiment carried out at these parameter values, then the coating process through the ring, switch back to the starch, without glyoxal and filler, at the same time maintaining a higher content of solid products. Recent experience saves these values, but decreases the weight of paper per unit area, to assess the effect of stiffness on bending. Table 1 presents data on resistance to bending (bending stiffness) according Lorentzon & Wettre, the paper thickness and porosity according to Bendtsen, compared with control, without filler and with the standard content of the solid products of starch. Experiment 2 demonstrates the increase, compared with the control experiment, the thickness and hardness Flexural strength and reduced porosity. Experience 2 b also shows the more smooth surface, as determined by the number of smoothness Bendtsen, which decreases from 225/210 ml/min (mesh/face) to 205/195 ml/min (mesh/face). This decrease in porosity for experience 2 can be attributed to the filler, the closing surface and forming a smooth surface. The most important information is obtained by comparing Experiments 2, 3 and 4 c Experience 1 (control). The thickness increases with the addition of Reactopaque, and the bending stiffness is increased by increasing the thickness, in conjunction with increasing starch content located in the surface layers. The total starch content in the sheet is also increased due to the fact that the sheet becomes more open, with a higher number of porosity Bendtsen). Experience 4, in comparison with experiment 1, is particularly important because it demonstrates that the increase in stiffness bending allows for reduced mass per unit area, at the same time maintaining almost the same stiffness as in the control experiment.

Table 1
ExperienceProcessingMass per unit area g/m2Thickness
micron
W is strasti bending, mn
MD/CD
Porosity Bendtsen, ml/min
1Control80,399,4104/62880
2Reactopaque, the increase in the content of solids in the starch, in combination c glyoxal and GCC80,3to 102.3117/57715
3Reactopaque, the increase in the content of solids in the starch79,8102,5121/55980
4Reactopaque, the increase in the content of solids in the starch,
the reduction of mass per unit area
to 78.3100,1107/581000

Example 2

A number of paper grades are estimated in the experiments dosed the sizing. Analyzed the main paper is produced with a density per unit area of 90 grams per square meter, without Reactopaque 100. In the control experiment C1, using this basic Boo the ASU, get coverage through the ring, with a mass per unit area of 2 g/m2in the control experiment C2 get coverage by sizing with a mass per unit area of 5 g/m2and in the control experiment C3 get coverage by sizing with a mass per unit area of 8 g/m2. Control experiments comparing, side by side, were carried out on the installation for dosed sizing investigated for a number of paper grades produced with mass per unit area of 88 grams per square meter, with the addition of 0.18% Reactopaque 100 before refining wood of firm breeds of a tree. Analyzed the main varieties of paper get coverage through the ring containing gidroksietilirovanny corn starch (Ethylex 2035 from A.E. Staley Manufacturing Co., Decatur, IL, USA) with a higher content of solid foods (18% instead of the standard 8%), c glyoxal and filler (ground calcium carbonate). Grade coated paper obtained by sizing, research on bending stiffness, smoothness and porosity. For summarizing the results of the build graph rigidity in bending as a function of smoothness, and the results were evaluated as smoothness in Sheffield, equal to 120, after calendering steel on steel. Number Gurley porosity and smoothness in Sheffield provides for uncalendered paper. The coefficient gig is scopically extensibility estimate on strips of paper, in the direction of the process and in the transverse direction, using a tester hygroscopic extensibility Varidim (Techpap, Grenoble, France). Hygroscopic extensibility is measured at a relative humidity between 15 and 90%, which calculates the coefficient of hygroscopic extensibility.

Various additives for solutions of the starch is chosen from the next following list:

Sodium tetraborate pentahydrate, borax (Neobor from US Borax, CA, USA)add in the amount of 0.25% of the starch before cooking starch.

Glyoxal (Sequarez 755, Omnova Solutions Inc., SC, USA) is added in an amount of 5% of the starch in combination c precipitiously calcium carbonate is added in the amount of 50% compared to starch (Megafil 2000, Specialty Minerals, PA, USA).

Polyvinyl alcohol (Celvol 325 from Celenese Chemicals, TX, USA) is added in an amount of 5% of the starch.

Table 2 shows the results. The combination of high content of solids in the starch and the viscosity modifier/filler/agent for cross-linking increases the bending stiffness by more than 20% compared with the control experiments. By itself, the high content of solids in the starch also gives some advantage, but an unexpected result represents the total impact on several important properties of paper by applying filler and sizing. The use of taped which gives more of an indoor sheet, as can be seen by increasing numbers of porosity Gurley, the main paper containing a filler, is smoother, and the coefficient of hygroscopic extensibility is significantly lower for the experiments with the combination of the high content of solids in the starch and the viscosity modifier/filler/agent for cross-linking.

Example 3

A number of papers formed from a mixture of 8 parts of wood pulp Northern hardwoods and 2 parts wood pulp Northern soft wood, and with 20% filler, precipitating calcium carbonate (Megafil 2000) from Specialty Minerals. Wood pulp rafinuyut together and they have a Canadian Standard Freeness of about 450 ml. Standard glue AKD (Hercon 70 from Hercules add in the wire section into the main sheet number for Hercules studies glue 50-100 seconds. Reactopaque 100 (subject to 0.17 wt.%) add before refining at a temperature of wood pulp 54°C (130°F) to achieve the effect of increasing the volume. These varieties of paper will explore the twisting in a hot condition by using the appropriate tool developed for such measurements on behalf of the research center of International Paper. The results are shown in table 3. They show that adding Reactopaque 100 to the main sheet gives a significant reduction in the number of twist (once the Itza 5 units is considered as a significant difference).

Table 3
Sample paperProcessingTwisting in the hot condition, millimeters
175 grams per square meter without Reactopaque 10042
280 grams per square meter without Reactopaque 10032
375 grams per square meter add Reactopaque 10025
480 grams per square meter add Reactopaque 10020

Although the present invention is described with references to preferred embodiments of the person skilled in the art it will be clear that in light of the above descriptions are different versions. For example, you may change the optimum amount of filler used in conjunction with various types and relations cellulose fibers. All such changes and modifications as expected, are within the scope and spirit of the present invention, as defined in formulas the invention, attached.

1. Paper or paperboard having improved bulk and stiffness, containing
three-layer, forming a single fabric flange structure having a top layer, a Central layer and the bottom layer, in which the Central layer is a cellulosic core layer and the upper and lower layers are layers of the coating based on starch, which cover the upper and lower surfaces of the Central layer with minimal penetration into the Central layer, and a filler, penetrating into the Central layer.

2. Paper or cardboard according to claim 1, in which the ratio of the thickness of the Central layer in comparison with the thickness of the paper or cardboard is in the range between 1:50 and 1:1,1.

3. Paper or cardboard according to claim 1, in which the weight per unit area of paper is in the range from 59 g/m2up to 410 g/m2and mass per unit area of each of the upper and lower layers of the coating is in the range from 2 to 10 g/m2.

4. Paper or cardboard according to claim 1, in which the filler is made of a polymeric material in the form of microspheres.

5. Paper or cardboard according to claim 1, in which the upper and lower layers are formed from a solution for sizing based on starch having a solids content of products of starch in the range from 6 to 20 wt.%.

6. Paper or cardboard according to claim 1, in which the filler is a product is based on diamide salt.

7. Paper or cardboard according to claim 1, in which the filler is made of a polymeric material in the form of microspheres selected from the group consisting of methyl methacrylate, orthochlorotoluene, paleontological, polyvinylidenechloride, Acrylonitrile, vinylidenechloride, para-tert-butylstyrene, vinyl acetate, butyl acrylate, styrene, methacrylic acid, vinylbenzoic and combinations of two or more of the above.

8. Paper or cardboard according to claim 7, in which a Central layer further comprises a retention agent.

9. Paper or cardboard according to claim 1, in which a Central layer further comprises an additive selected from the group consisting of fillers, surfactants, bonding agents or their combinations.

10. Paper or cardboard according to claim 1, in which the starch is selected from the group consisting of gidroksietilirovannogo starch, oxidized starch, cation-modified or enzyme-converted starch from any of the commonly used source of starch, such as potatoes, corn, wheat, rice or tapioca.

11. Paper or cardboard according to claim 1, in which the upper and lower layers additionally contain an agent for cross-linking.

12. Paper or cardboard according to claim 1, in which the upper and lower layers additionally contain a viscosity modifier.

13. Paper or cardboard according to claim 1, in which the Torah top and bottom layers additionally contain a pigment.

14. Paper or cardboard according to claim 1, further containing an additive selected from the group consisting of polyvinyl alcohols, ammonium zirconium carbonate, borate chemicals, glyoxal, melamineformaldehyde, crushed and precipitiously of calcium carbonate, clay, talc, TiO2and of silicon oxide or combinations thereof.

15. Paper or cardboard according to claim 1, in which the upper and lower layers is formed by coating a solution of starch containing solid products from 12 to 20 wt.%.

16. Paper or cardboard according to claim 1, in which the upper and lower layers is formed by coating a solution of starch containing solid products from 12 to 18 wt.%.

17. Paper or paperboard having improved bulk and stiffness, containing
three-layer, forming a single fabric flange structure having a top layer, a Central layer and the bottom layer, in which the Central layer is a cellulosic core layer, and upper and lower layers are layers of the coating based on starch, which cover the upper and lower surfaces of the Central layer, the coating weight based on the starch of each of the upper and lower layers of the coating is in the range from 2 to 10 g/m2and the filler, which penetrate the cellulosic core layer.

18. Method for manufacturing paper or paperboard, including stage
a) create a component is icii, containing pulp fibers and filler
b) formation of fibrous webs of the composition for paper manufacturing,
c) treating the fabric with a solution of starch-based with the formation of the upper and lower layers of coating with high strength in the upper and lower side of the fiber fabric, and
d) drying the treated fibrous webs with formation of a three-layer, forming a single fabric material, having a double-t structure.

19. The method according to p in which the ratio of the thickness of the fiber fabric in comparison with the thickness of the paper or cardboard is in the range between 1:50 and 1:1,1.

20. The method according to p, in which the mass per unit area of paper is in the range between 59 g/m2and 410 g/m2and mass per unit area of each of the upper and lower layers of the coating is in the range between 2 and 10 g/m2.

21. The method according to p, in which the level of starch from the upper and lower layers of the coating to the fibrous fabric is negligible.

22. The method according to p, in which the upper and lower layers of coatings solids content of products starch is less than 20 wt.%.

23. The method according to p, in which the processing using the device for dosed sizing.

24. The method according to p, in which the filler is a product based on diamide salt.

25. The way is about p, in which the composition additionally contains an additive selected from the group consisting of fillers, surfactants or combinations thereof.

26. The method according to p, in which the starch is selected from the group consisting of gidroksietilirovannogo starch, oxidized starch, cation-modified or enzyme-converted starch from any of the commonly used source of starch, such as potatoes, corn, wheat, rice or tapioca.

27. The method according to p, in which the solution for the ring optionally contains an additive selected from the group consisting of polyvinyl alcohols, ammonium zirconium carbonate, borate chemicals, glyoxal, melamineformaldehyde, crushed and precipitiously of calcium carbonate, clay, talc, TiO2and of silicon oxide or combinations thereof.

28. The method according to p, in which the starch solution to a solution of starch-based high strength pre-cook with borate chemical before processing through the ring.

29. The method according to p, which is used with the filler polymer material in the form of microspheres.

30. The method according to p, which is used with the filler polymer material in the form of microspheres selected from the group consisting of methyl methacrylate, orthochlorotoluene, paleontological, polyvinylbutyral is Yes, Acrylonitrile, vinylidenechloride, para-tert-butylstyrene, vinyl acetate, butyl acrylate, styrene, methacrylic acid, vinylbenzoic and combinations of two or more of the above.

31. The method according to p, which use a solution based on starch solid content of products from 12 to 20 wt.%.

32. The method according to p, which use a solution based on starch solid content of products from 12 to 18 wt.%.



 

Same patents:

FIELD: printing industry.

SUBSTANCE: method is related to production of materials for printing and may be used in printing industry. Method includes application of fixing agent and composition that prevents twisting onto base. Fixing agent includes plurivalent salt of metal and cation polymer. Composition that prevents twisting includes aminoxide. This method is used to produce printing material that contains printing base and applied abovementioned fixing agent and composition that prevents twisting.

EFFECT: reduced twisting of paper.

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EFFECT: increased quality of paper or cardboard due to increased smoothness, decreased hygroscopic expansivity, improved fold resistance and paper rolling resistance.

30 cl, 2 dwg, 3 tbl, 3 ex

FIELD: textile; paper.

SUBSTANCE: method relates to production paper material and can be applied in paper-and-pulp industry when producing paper material with low-density. Method includes formation of aqueous suspension containing pulp. Addition of latex with agglomerated hollow particles in suspension. Formation of a wet sheet from the suspension and drying of the sheet. It also relates to paper material prepared by using the method.

EFFECT: production of paper material having good combination of optical, mechanical, tactile properties, evenness and volume including economical efficiency of the process.

10 cl, 6 dwg, 2 ex

FIELD: textile, paper.

SUBSTANCE: paper material and method of its production are designed for the production of paper products such as file folders and can be used in pulp and paper industry. The paper material contains cellulose fibers and expanded microspheres in the amount of approximately 0.1-0.4 wt % and 5.1-6.0 wt % of the web total dry weight; the paper web has the density equal to or exceeding about 6.0 pounds per 3000 square feet per mil. Method of manufacturing this material involves preparing composition for paper production containing cellulose fibers and expanded microspheres in the above amount, forming a fibrous web from this composition, web drying and calendering up to the above thickness.

EFFECT: preventing skin cuts, improving flexibility and stiffness of paper material.

29 cl, 25 dwg, 14 tbl, 8 ex

FIELD: pulp-and-paper industry, in particular, paper sheet having surface feeling hash to the finger, and method for applying coating onto paper sheet.

SUBSTANCE: paper sheet of such structure may be used for manufacture of paper or plastic medium for carrying of printed information, paper or plastic package, cover used in stitching and binding processes, or cardboard or plastic carton having surface feeling hash to the finger. At least one side of paper sheet is coated with layer containing non-compressible microscopic particles of non-gelatinized starch grains, or said particles are produced by grinding of plastic material. Method involves treating at least one side of paper sheet with water-based composition containing non-compressible microscopic particles which are made three-dimensional and rounded, binder, and filler; drying paper sheet after treatment. Particles are non-gelatinized starch grains, or particles are produced by grinding of plastic material. Method allows paper sheet to be produced, which has roughness coefficient Kd below 0.5.

EFFECT: simplified method and improved quality of paper sheet.

17 cl, 16 dwg, 1 tbl, 3 ex

FIELD: paper coated with composition for coating various kinds of paper, for offset printing of paper used for manufacture of books, magazines, annual reports, or packaging paper.

SUBSTANCE: composition comprises pigments and binder. Composition pigments are formed as microballs having sizes below 10 micrometers, preferably about 7 micrometers. Paper coated with such composition is silky by touch and has at least one surface coated with such composition, preferably both of its surfaces. This paper may be tracing paper.

EFFECT: improved quality of paper owing to preventing sliding thereof during separation of sheets in stacks, delamination of coating during printing process and, accordingly, elimination of paper dusting and formation of impure imprints.

7 cl, 2 dwg, 2 tbl, 13 ex

The invention relates to thermosensitive recording materials, in particular paper and taking into account the major area of application is the production of business and securities can be attributed to the means of their protection against forgery
The invention relates to the production of paper containing various means of protection against counterfeiting and unauthorized manufacture, and more particularly to securities with protective means, the action of which is based on the phenomenon of thermal sensitivity, t

FIELD: textile, paper.

SUBSTANCE: method relates to paper or cardboard production and can be used on pulp-and-paper industry. Part of paper pulp fiber is treated with a polymer at least within two stages. Paper pulp treated with the polymer is mixed with remaining non-treated paper pulp. The mixed paper pulp is dehydrated on a net conveyor for forming fibrous web.

EFFECT: increase of strength without negative effect upon paper or cardboard volume with decreasing quantity of adding polymers and enhancing economical efficiency of the process.

14 cl, 4 dwg, 2 ex

FIELD: textile; paper.

SUBSTANCE: method relates to production paper material and can be applied in paper-and-pulp industry when producing paper material with low-density. Method includes formation of aqueous suspension containing pulp. Addition of latex with agglomerated hollow particles in suspension. Formation of a wet sheet from the suspension and drying of the sheet. It also relates to paper material prepared by using the method.

EFFECT: production of paper material having good combination of optical, mechanical, tactile properties, evenness and volume including economical efficiency of the process.

10 cl, 6 dwg, 2 ex

FIELD: medicine.

SUBSTANCE: absorbing cloth from a cellulose fiber contains an admixture of hard wood and soft wood fibers located in the form of mesh structure, including: the set of columnar areas fibers conglomeration with relatively high local density, aggregated by means of set of the connecting areas with lower local density, where orientation of fibers is inclined along a longitudinal direction between the columnar areas interconnected in a such way, where the cloth possesses coefficient of elongation in a cross-section direction, which is at least in 2.75 times higher than relative strength at cloth stretching in a dry condition. The above-stated material is obtained as follows. A water cellulose composition from hard wood fibers is prepared. The composition is moved on a forming tissue in the form of a stream which is let out from a pressure head box with a flow rate. The composition is dehydrated and compacted for manufacturing of a paper for formation of the fibrous layer possessing chaotic distribution of a fiber for paper manufacturing. Packing of the dehydrated fibrous layer possessing chaotic distribution of a fiber on the transporting transferring surface moving with the first rate. Creping of a fibrous layer from the transferring surface on a tape at dryness from 30% to 60% with use of the pattern creping tape. The creping stage is carried out under pressure in a contact zone of the creping tape confined between the transferring surface and the creping tape. Thus the tape is moved with the second speed, lower than speed of the transferring surface. Tape drawing, parametres of a contact zone, speed difference and dryness of the fibrous layer are chosen in such way to crepe the fibrous layer at its removal from the transferring surface and to redistribute on the creping tape with formation of a fibrous layer with mesh structure. Drying of the fibrous layer is performed after. The process is regulated so that coefficient of elongation in a cross-section direction is, at least, approximately in 2.75 times higher than relative strength at stretching of the fibrous layer in a dry condition. Such method allows obtaining a cellulose fibrous layer for products made from thin paper, and also products in the form of towels.

EFFECT: improvement of ready product quality and power consumption decrease.

33 cl, 10 dwg, 22 tbl

Composition // 2347030

FIELD: textiles; paper.

SUBSTANCE: composition is meant for improving the softness of paper products. Composition includes: (i) oil, fat or wax; (ii) at least one non-ionic surfactant; (iii) at least one anion compound, selected from anionic micro-particles and anionic surfactant; (iv) at least one polymer, which is a cation, non-ionic or amphoteric, where the non-ionic surfactant is added to the amount from about 60 to 1000 weight fractions for 100 weight fractions of the polymer. Composition is used in the method of manufacturing paper (versions). Method includes adding the mentioned composition to a cellulose suspension or to a moist or dry paper fabric.

EFFECT: increase in the quality of the paper products due to the increase in its softness, low resistance to tearing and high speed of getting wet and reduction in energy for pulping.

22 cl, 9 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: invention can be used for production of deposited calcium carbonate used as paper filler. Secondary particle diameter of deposited calcium carbonate is 1-10 mcm. Deposited calcium carbonate consists of aggregated primary particles of spindle calcium carbonate with greater particle diameter within 0.5 to 3.0 mcm, smaller diameter within 0.1 to 1.0 mcm with ration of specified diameters equal to 3 or more. Specific surface area BET of primary particles of calcium carbonate is 8-20 m2/g, cell volume is 1.5-3.5 cm3/g. Method of production of deposited calcium carbonate includes as follows. Carbon dioxide or carbon dioxide gas is injected in calcium hydroxide suspension concentrated 100-400 g/l, prepared by wet calcined liming activity of which 4 "н." HCl at third minute value is reduced to 150-400 ml. Reaction is resulted in carbonisation degree within 50 to 85%. Then 1 to 20 vol % of calcium hydroxide suspension is added. Reaction is complete with injection of carbon dioxide or carbon dioxide gas. The paper containing the specified calcium carbonate as filler is offered as well.

EFFECT: enhanced paper bulkiness.

7 cl, 2 tbl, 10 ex

FIELD: textiles, paper.

SUBSTANCE: paper or cardboard of improved rigidity and bulk are meant for reproducing equipment and the method refers to production of the said paper and cardboard. The paper or cardboard has the core layer and starch-based layers applied by gluing-up on its both sides forming the uniform canvas of the double-T structure. The layers cover the upper and the lower surface of the central layer with minimal penetration to the central layer. The starch contains the filler spreading to the central layer. The starch has high content of solid products. The mass of the coating layers is 2-10 g/m2. Method for producing paper or cardboard includes the following stages: a) creation of composition containing cellulose fibers and the filler, b) formation of fibrous canvas, c) drying of the fibrous canvas, d) processing by gluing-up both sides of the dried canvas with the starch with filler and e) drying of the fibrous canvas with formation of the three-layer making the uniform canvas material with the double-T structure.

EFFECT: increased quality of paper or cardboard due to increased smoothness, decreased hygroscopic expansivity, improved fold resistance and paper rolling resistance.

30 cl, 2 dwg, 3 tbl, 3 ex

The invention relates to a method of manufacturing down with superior adsorption capacity and to Pooh obtained in this way

The invention relates to a method of manufacturing absorbent material with superior adsorption capacity, absorbent material obtained in this way, and absorbent articles containing such material

The invention relates to the production of a composite fiber material having a high hydrophilic properties and intended for use in various fields of national economy in the manufacture of products to which the requirements of high sorption capacity, capillary transport and filtration properties

FIELD: paper industry.

SUBSTANCE: anti-deception paper (1) consists of multi-layer ready-to-crease substrate with paper layer (4), its both sides being furnished with film (6) provided with protective sign covering completely the aforesaid paper layer surface.

EFFECT: dirt-repellant properties and higher strength of paper.

19 cl, 11 dwg

FIELD: textiles, paper.

SUBSTANCE: paper or cardboard of improved rigidity and bulk are meant for reproducing equipment and the method refers to production of the said paper and cardboard. The paper or cardboard has the core layer and starch-based layers applied by gluing-up on its both sides forming the uniform canvas of the double-T structure. The layers cover the upper and the lower surface of the central layer with minimal penetration to the central layer. The starch contains the filler spreading to the central layer. The starch has high content of solid products. The mass of the coating layers is 2-10 g/m2. Method for producing paper or cardboard includes the following stages: a) creation of composition containing cellulose fibers and the filler, b) formation of fibrous canvas, c) drying of the fibrous canvas, d) processing by gluing-up both sides of the dried canvas with the starch with filler and e) drying of the fibrous canvas with formation of the three-layer making the uniform canvas material with the double-T structure.

EFFECT: increased quality of paper or cardboard due to increased smoothness, decreased hygroscopic expansivity, improved fold resistance and paper rolling resistance.

30 cl, 2 dwg, 3 tbl, 3 ex

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