Method for manufacturing of cardboard and method for reducing moisture-permeability of cardboard

FIELD: production of cardboard for manufacture of packages for liquids.

SUBSTANCE: method involves treating fibrous mass designated for preparing of cardboard with percarbonic acid used in an amount of 0.5-5 kg per t of dry fibrous mass on conversion to 100%-concentration of percarbonic acid; thereafter or simultaneously with indicated treatment process, providing gluing-through by combining resin-based and neutral adhesives; forming cardboard.

EFFECT: reduced moisture-permeability and improved quality of gluing-through of cardboard.

11 cl, 3 tbl, 3 ex

 

The technical field

The invention relates to a method of manufacturing a carton for packaging liquids, as well as to the way by which you can improve the properties of cardboard for such purpose, in particular their resistance to penetration of liquid.

The level of technology

The use of peracetic acid for bleaching modifications of cellulose is known, for example, patent publication Japan JP 57-21591. Methods bleaching of this type have as their goal the removal of lignin from the pulp, and in this case we are not talking about any intention to modify the surface of the fiber for process sizing, as in the case described method according to the present invention.

From the patent application Finland FI 974575 known method of bleaching modifications of cellulose containing after bleaching stage in which peracetic acid is used in the presence of compounds of the alkaline earth metal. The specific purpose of this phase is to improve the degree of whiteness of pulp.

In patent publication Finland FI 104339 describes the way in which bleached pulp (cellulose) modify peracetic acid before gluing neutral glue. The method refers to the process of manufacturing high-grade paper, in which a bleached pulp after treatment peracetic acid injected is the process of making paper using neutral glue. In the method described in this publication to be processed fibrous mass should be replaced (whiteness more than 85% ISO and a Kappa number less than 4). Thus, publication Fl 104339 refers to the way in which before processing peracetic acid lignin is removed from the treated fibrous mass. As will be described later, in the method according to the present invention the fibrous mass to be processed, contains a significant amount of lignin, and the sizing is carried out with a sizing composition containing a resin adhesive.

In the publication Tappi (Technical Association of Pulp and Paper Industry Technical Association of the pulp and paper industry) 2/1965, Vol.48, No. 2 (Paper Bleaching - A New Process, W.H.Rapson et al.) describes the method of bleaching paper, including peracetic acid. This method aims to increase the degree of whiteness of the paper product. In the described method peracetic acid is used in substantial quantities. For example, the on p.68 in the second paragraph of the dose is approximately 1.2 to 2.5% (i.e. 12-25 kg per ton of pulp). This dose can dissolve significant amounts of lignin and other products of the pulp, thereby sharply breaking the paper manufacturing process.

The use of percolat as biocides known, for example, from the publication Kemia-Kemi, No. 3 (1995), Jyri Maunuksela, Mikrobien torjunta peetikkahapolla (Microbe Prevention with Peracetic Acid), pp.242-244. This method seeks only destruction of the microbial populations in the paper machine. Obviously, peracetic acid, known as an effective biocide, provided it is present in sufficient amount to inhibit the activity of microbes in the circulating water. In the method described in this publication, we use the so-called equilibrium peracetic acid, which contains a significant amount of free acetic acid and free hydrogen peroxide. These components being present in peracetic acid, can inhibit the process of making paper.

For use in bleaching modifications wood pulp also described activators, together with hydrogen peroxide producing percolate. This method is described, for example, Appita Journal, Vol.51, No.4, pp.306-310 (C. Leduc et al.). The purpose of this method is the increase in the degree of whiteness of the pulp. However, he has a disadvantage in significantly increased doses of chemicals.

It was also suggested that bleaching methods based on percolate aimed at increasing the degree of whiteness of pulp compared to conventional methods of bleaching. This method is described, for example, Pulp and Paper Magazine of Canada, Convention Issue, 1972, pp.123-131 and 3/1968, pp.51-60 of the same magazine. Applied in these methods, the dose is percolate very large, composing is usually 1% (i.e. 10 kg per ton of pulp), and thus they dissolve significant amounts of lignin from the surface of the fibers. The goal of these methods is to increase the degree of whiteness of the pulp, i.e. bleaching.

Next, from the publication of the international application WO 00/77301 A1 is known a method of improving the opacity of wood pulp by adding percarbonates acid to a bleaching solution containing hydrogen peroxide, or by carrying out processing percarbonates acid for wood pulp, bleached with hydrogen peroxide or dithionite. Using this method produces paper with high opacity.

The invention

The problem to which the present invention is directed, is to develop a method of making paper Board for packaging liquids, with the implementation of this method in cardboard improves, in particular, resistance to penetration (SOP) of the liquid. In the manufacture of cartons for such purpose a list of important parameters include the so-called SOP lactic acid and SOPS peroxide, which characterize the penetration of solutions of lactic acid and peroxide in the cardboard. From the point of view of the suitability of such a Board is essential that the liquid could not penetrate the cardboard. It was found that by obrabatyvaemoi mass, intended for the manufacture of cardboard, a small dose percarbonic acid and after this sizing with the mixture of resin and neutral adhesives it is possible to obtain a significant improvement. The essential feature of the invention is that the surface of the fibers in the fibrous mass, intended for the manufacture of cardboard, first modify by processing percarbonic acid, followed by the sizing with the specified sizing composition.

When conducting percolate treatments known from the above publications, the task was primarily an increase in the degree of whiteness or improving the opacity, as well as, through the use of percolate as a biocide, inhibition of microbial growth. The invention particularly relates to a procedure in which in the method of manufacturing a carton for the packaging of liquids in the preparation of sizing applied processing percarbonates acid for surface modification of fibers in the fibrous mass, intended for the manufacture of paperboard and containing lignin.

Thus, according to the invention is provided a method of manufacturing a carton for the packaging of liquids, in which the fibrous mass, intended for the manufacture of cardboard, treated percarbonates acid by adding it to the fibrous mass in the amount of 0.5-5 kg per ton of dry fiber weight based on 100-percent concentration percarbonic acid, after or simultaneously with the above treatment is carried out to repair with a combination of resin and neutral adhesives, and then forming the carton.

According to the invention the sizing with a combination of resin and neutral adhesives preferably carried out after processing percarbonic acid.

For sizing, you can apply the mixture of resin and neutral adhesives or they can be added to the fibrous mass separately.

Applied fibrous mass, intended for the manufacture of cardboard, may be wood pulp such as ground wood (SOW, PGW), refiner groundwood (TSR) or chemical-mechanical wood pulp (STMR), and unbleached cellulose or mixtures thereof. Together with the above modifications fibrous mass can be applied in the form of a mixture of types of pulp, such as Kraft pulp. From the point of view of functional features of the invention, the wood species used for the manufacture of pulp, are not a significant parameter.

The preferred dose percarbonates acid is 1-3 kg per ton of pulp. Applied acid of this type can be any percarbonates acid with moderate solubility in water. It was shown that the preferred are paranavitana, peracetic, burpropion the OIC acid, a particularly preferred was not containing peroxide distillates made from their equilibrium solutions. The cooking process percarbonates acid does not affect the functional characteristics of the invention. As such acid can be applied solutions percarbonic acid, purified by distillation or in any other way, and the equilibrium solutions of these acids. Suitable for use with various mixtures percarbonic acids. In one embodiment of the invention can be applied mixture percarbonic acid and inorganic percolate, such as acid Caro. In another embodiment of the invention peracetic acid can be prepared from hydrogen peroxide and an activator, such cactoid (tetraacetylethylenediamine).

In the method according to the invention for gluing apply a combination of resin and neutral adhesives. The resin may be a resin or resin with the reinforcing agent. Neutral adhesive can be alkyllithium dimer (AKD), alkenylamine dimer, anhydride alkenylamine acid or anhydride ultilateral acid, preferably one of them is AAA. Depending on the nature of the process quantity of the adhesive and the pH value can be changed, respectively, in the intervals of 1-10 kg per ton of dry fiber mass and 3-11, preferably 4-9. Resin and neutral the capacity adhesives can be added to the fibrous mass in the form of a mixture or separately, as well as the combined adhesive. Dosed ratio of resin glue/neutral adhesive can be varied in a wide range, but the preferred ratio, based on weight values are in the range of 9:1-1:9. It is also obvious that the moment of the process, which add glue, the order in which you add other chemicals, or other operating parameters of the paper machine are not factors affecting the functional characteristics of the invention. For the invention it is essential that the mixed fibrous mass is directed to a process for the manufacture of cardboard after processing percarbonic acid, and a specific process for sizing use neutral adhesive, preferably AAA, and resin glue.

According to the invention the procedure can also be in a form in which a portion of the fibrous mass, intended for the manufacture of cardboard, treated percarbonic acid, and then this processed mass combined with the same fibrous mass, which has not been specified processing. After that, the mixed fibrous mass is subjected to the sizing. In this case, for example, wood pulp can be processed percarbonic acid and combined with the cellulose, not treated in this way.

In one of the preferred embodiments of the invention about the working percarbonic acid and/or phase sizing is carried out in the presence of the agent, stabilizing the specified acid. Such a stabilizing agent can be different complexing agents, such as TPC (diethylenetriaminepentaacetic acid) or EDTA (ethylenediaminetetraacetic acid), and phosphonates, such as DTPMPA, or M-bis-[(1,2-dicarboxylate)-ethyl]amine and M-Tris-[(1,2-dicarboxylate)-ethyl]amine. As a stabilizing agent can also be used salts of alkaline earth metals such as calcium, such as calcium acetate or calcium carbonate, and magnesium compounds such as magnesium sulfate, and aluminum compounds such as alum. Complexing agents can also be used in the form of their salts of alkaline earth metals. Particularly preferred variant of the method according to the invention consists of adding complexing agents simultaneously with the sizing mixture. The invention relates also to the procedure, during which containing aluminum compound, such as alum, is added to the fibrous mass or together with treatment percarbonic acid, or thereafter.

The consistency and temperature of the fibrous mass, intended for the manufacture of cardboard, at the stage of adding percarbonates acid can be, respectively, 0.1 to 40% and 20-100°C. As mentioned above, the pH of the mass depending on the nature of the RA process can be 3-11, preferably 4-9. The acceptable duration of the reaction is 1-300 min depending on the nature of the process. The gap between the processing percarbonic acid and sizing does not impact significantly on the functional features of the invention; both of these operations can be carried out simultaneously.

According to the invention further provides a method of improving the resistance of paperboard for packaging liquids penetration of liquid. In this way in the manufacture of cardboard fibrous mass that is used for its manufacture, process percarbonates acid by adding it to a fibrous mass in the amount of 0.5-5 kg per ton of dry fiber weight based on 100-percent concentration percarbonic acid, after or simultaneously with the above treatment is carried out to repair with a combination of resin and neutral adhesives.

In the methods according to the invention appointment percarbonates acid is not bleaching the pulp; it consists in modifying the surface of the fibers to the proper state before gluing. After that, the mixed fibrous mass is subjected to the sizing proper sizing composition containing a resin and a neutral adhesives, preferably AAA. In addition to improving the sizing application percarbonate acid lowers active the feature of microbes in the paper machine and reduces the smell of cardboard.

Due to the fact that according to the invention the dose size percarbonates acid is small, this acid does not dissolve the lignin and other substances fibrous mass and therefore does not affect the process of manufacturing of cardboard. Special advantages provides application solutions percarbonic acid, treated so that they contain only the required amount of these acids and water. In this case, adding percarbonic acids does not influence significantly on the pH of the mass, and in the process will not be an excess of (COD). A specific difference of the invention from known methods based perkiset is the fact that the problem to which it is directed, is not to increase the degree of whiteness, and in increasing the efficiency of sizing, resulting in reduced penetration of liquids into the cardboard.

The method according to the invention is not bleaching, and chemicals applied in the real bleaching fibrous mass, does not have any impact on the functional features of the way. Wood pulp can be bleached by dithionite, peroxide, both of these substances; in addition, it can be completely unbleached. Chelating or any other auxiliary agents used in the preparation of the fibrous mass, also do not affect the functional nature of the sticks of the invention.

Information confirming the possibility of carrying out the invention

Hereinafter the invention is described in more detail using examples. In the present description interest are the masses. interest, if no other special instructions.

Example 1

Wood pulp STMR before gluing processed phenpropionate acid (ACC). Applied phenpropionate acid was prepared by distillation of the equilibrium solution of the specified acid; the solution did not contain significant quantities of free peroxide or propionic acid. A mixture of wood pulp STMR and unbleached Kraft pulp of softwood was subjected to sizing system resin-AAA (control variant, Rear.) and combined with glue (Comb.). Sheet defined SOPS lactic acid (MK) and SOP peroxide; these parameters characterize the penetration of solutions of lactic acid and peroxide in the sheet. The results obtained are shown in Table 1.

Table 1
Fibrous massCTR. 5/3Comb. 5/3
MKH2About2MKH 2About2
Raw0,371,210,751,17
Processed ACC0,371,010,811,05

Mixed fibrous mass: STMR 40%, unbleached Kraft pulp of softwood 60%.

Processing CPD/STR: 60 minutes, 60°With the consistency of 5%, the dose of CPD 3.3 kg per tonne of pulp, pH 7,2.

Bonding with the consistency of 0.3%by weight of the sheets 130 g/m2.

CTR. 5/3: alum 6.5 kg per tonne of pulp + resin glue 5 kg per ton of pulp + Hydrores 360M (AAA) 3 kg per ton of pulp.

Comb. 5/3 (combined glue): resin glue 5 kg per ton of pulp + AAA 3 kg per ton of pulp.

MK=SOP lactic acid, 1 hour, 1% solution of lactic acid, room temperature.

H2O2=SOP peroxide, 10 min, 35%, 70°C.

From the obtained results we can conclude that the processing of CPD definitely improves SOP peroxide.

Example 2

Wood pulp STMR before the sizing was treated with peracetic acid (a BUNCH). Applied peracetic acid prepared by distillation of the equilibrium solution of the specified acid; the solution did not contain significant quantities of free hydrogen peroxide or acetic acid. The mixture of the trees the red mass STMR and unbleached fibrous mass ZV was subjected to sizing as with the system resin + AAA (control option CTR.), and with the combined adhesives (Comb.). For glued sheets defined SOPS lactic acid (MK) and SOP peroxide. The results obtained are shown in Table 2.

Table 2
Fibrous massCTR. 4,2/2,5Comb. 5/3 (5+3)Comb. 1/3 (1,4+4,1)
MKH2O2MKH2About2MKH2O2
Raw(1)0,341,23
Processed BUK (1)0,320,99
Raw(2)0,751,17
Processed a BUNCH of (2)0,701,09
#x0200A;
Raw(3)0,693,15
Processed a BUNCH (3)0,69of 2.26

MK=SOP lactic acid. N=SOP peroxide.

(1): mixed fibrous mass: STMR 50% and unbleached fibrous mass SA 50%.

Processing a BUNCH of/STR: 60 minutes, 60°With the consistency of 5%, the dose of a BUNCH of 3 kg per ton, pH 7.

Bonding with the consistency of 0.3%by weight of the sheets 130 g/m2.

CTR. 4,2/2,5: alum 5.5 kg per tonne of pulp + resin adhesive 4.2 kg per tonne of pulp + AAA 2.5 kg per tonne of pulp.

(2): mixed fibrous mass: STMR 40% and unbleached fibrous mass SA 60%.

Processing a BUNCH of/STR: 60 minutes, 60°With the consistency of 5%, the dose of a BUNCH of 3 kg per ton, pH 7,2.

Bonding with the consistency of 0.3%by weight of the sheets 130 g/m2.

Comb. 5/3 (combined glue): resin glue 5 kg per ton of pulp + AAA 3 kg per ton of pulp.

(3): mixed fibrous mass: STMR 40%, unbleached fibrous mass

SA 30%, waste 30%.

Processing a BUNCH of/STR: 5 min, 80°With the consistency of 3%, the dose of a BUNCH of 3 kg per ton. Procla is and when the consistency of 0.3%, weight sheets 130 g/m2. Comb. 1/3 (combined glue): resin 1.4 kg / tonne + AAA 4.1 kg per tonne. From the obtained results we can conclude that the processing of the BUNCH especially well improved SOPS peroxide.

Example 3

Unbleached Kraft pulp of softwood prior to sizing was treated with peracetic acid (a BUNCH). The fiber was subjected to a sizing system resin + AAA. Sheet defined SOPS lactic acid (MK) and SOP peroxide. The results obtained are shown in Table 3.

Table 3
Fibrous massCTR. 4/0,8
MKH2O2
Raw0,470,66
Processed a BUNCH0,580,45

Fibrous mass: unbleached Kraft pulp of softwood. Processing of the BUNCH: 10 min, 60°With the consistency of 5%, the dose of a BUNCH of 3 kg per ton, pH 7.

Bonding with the consistency of 0.3%by weight of the sheets 130 g/m2.

CTR. 4/0,8: alum 4.8 kg / tonne + resin 4 kg per ton + AAA 0.8 kg per tonne.

From the obtained results we can conclude that in the case of Kraft pulp of softwood when processing a BUNCH improves the SOP is ercise.

1. A method of manufacturing a carton for packaging liquids, characterized in that the fibrous mass, intended for the manufacture of cardboard, treated percarbonates acid by adding to the fibrous mass percarbonates acid in the amount of 0.5-5 kg per ton of dry fiber mass based on 100%concentration percarbonic acid, after or simultaneously with the processing of percarbonic acid are sizing with a combination of resin glue and neutral glue, and then forming the carton.

2. The method according to claim 1, characterized in that the gluing is carried out after processing percarbonates acid using a mixture of resin glue and neutral glue.

3. The method according to claim 1 or 2, characterized in that the neutral glue is alkylcatechols dimer, alkenylamine dimer, anhydride alkenylamine acid or anhydride ultilateral acid, preferably alkylcatechols dimer.

4. The method according to any of the preceding paragraphs, characterized in that the fibrous mass intended for the manufacture of cardboard, is wood pulp or unbleached cellulose, or mixtures thereof.

5. The method according to any of the preceding paragraphs, characterized in that percarbonate acid is permorming acid, peracetic acid or phenpropionate acid, predpochtite the flax distilled peracetic acid.

6. The method according to any of the preceding paragraphs, characterized in that percarbonate acid is added to the fibrous mass, intended for the manufacture of cardboard, in the amount of 1-3 kg per ton of dry fiber mass based on 100%concentration percarbonic acid.

7. The method according to any of the preceding paragraphs, characterized in that the consistency of the pulp intended for the manufacture of cardboard, at the stage of adding percarbonates acid is 0.1-40%.

8. The method according to any of the preceding paragraphs, characterized in that the pH at this stage of sizing lies in the range of 3-11, preferably 4-9.

9. The method according to any of the preceding paragraphs, characterized in that the step of sizing add one or more agents, stabilizing percarbonate acid, such as complexing agent or a compound of alkaline-earth metal.

10. The method according to any of the preceding paragraphs, characterized in that the step of sizing add one or more aluminum compounds, preferably alum.

11. Method for improving the resistance of paperboard for packaging liquids penetration of liquids, characterized in that in the manufacture of cardboard fiber handle percarbonates acid by adding to the fibrous mass percarbonates acid is in the amount of 0.5-5 kg per ton of dry fiber mass based on 100%concentration percarbonic acid, after or simultaneously with the processing of percarbonic acid are sizing with a combination of resin glue and neutral glue.



 

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