RU2589671C1 - Method of producing hydrophobic and lipophobic paper using microfibrillar cellulose fibres - Google Patents

Abstract

FIELD: pulp and paper industry.

SUBSTANCE: invention relates to pulp and paper industry and can be used in manufacture of paper, in particular hydro- and lipophobic paper. Method involves preliminary preparation of material from pine and hardwood pulp, paper pulp preparation by way of addition in prepared raw water to produce fibrous suspension with mass concentration of 6 %, grinding obtained suspension, preparing composition by adding into produced paper mass of microcrystalline cellulose obtained from vegetable raw materials with a non-hydrolysis method, in form of hydrogel, introduction of a dimer of alkyl ketene and polyamide polyamine epichlorohydrin resin, production of paper samples on sheet-making apparatus.

EFFECT: obtained product is widely used in paper industry, in production of packaging materials, including oil and fat foods.

1 cl, 1 tbl

Description

The invention relates to the pulp and paper industry and can be used in the manufacture of paper, in particular hydro- and lipophobic paper.

Known water-repellent paper containing hydrophobic zeolite. Water-repellent paper may be in the form of paper, cardboard or laminated laminate. Also known is a method of producing water-repellent paper by forming and dehydrating a suspension of fibers containing lignocellulose, wherein dehydration is performed in the presence of a hydrophobic zeolite. Due to the inertness of the zeolite, it can be used in the manufacture of paper in a very wide pH range. The invention also relates to the use of hydrophobic zeolite for the production of water-repellent paper, as well as to the use of paper with the indicated water-repellent properties as packaging material (patent RU 92004323, publ. 20.10.1996). The use of hydrophobic zeolite helps to reduce the transfer from the package to its contents of substances that cause the appearance of an undesirable aftertaste and / or hazardous substances, but does not affect the lipophobic properties of the paper.

A known method of sizing cellulose fibers by adding to their dispersion an aqueous sizing dispersion containing as a sizing agent an alkyl ketene dimer (AKD) at a flow rate of from 0.01 to 1.0 wt. % based on the dry weight of cellulose fibers (RU 2177521, publ. 27.12.2001). In the manufacture of an aqueous sizing dispersion, the sodium salt of carboxymethyl cellulose (Na-CMC) is used as a dispersant in an amount of 100 wt. % and below the mass of AKD, or up to 1% calculated on the dry weight of cellulose fibers. The method allows to obtain paper with hydrophobic properties, however, it does not provide imparting lipophobic properties to the paper.

The closest to the invention in technical essence and the achieved result in terms of the method is a method of producing paper pulp for making paper containing hardwood and softwood pulp, a sizing agent, sodium salt of carboxymethyl cellulose, characterized in that it additionally contains microfibrillated fibers, the cellulose has a grinding degree of 33- 45 ° SR, and as a sizing agent, the mass contains an alkyl ketene dimer (patent RU 2471032, publ. 12/27/2012). The invention improves the strength of the paper, but does not have other properties claimed in the present invention.

The objective of the invention is to develop a method for producing paper samples with hydrophobic and lipophobic properties, high strength characteristics, ductility, using microfibrillar cellulose fibers, using low toxicity reagents in a minimum volume, with the possibility of scalability and reduce production costs.

The technical result of the invention is to improve the quality of the finished product having a high degree of hydro- and lipophobicity, high strength characteristics, which is widely used in the paper industry, in the production of packaging materials, including for fat-and-oil food products.

The method is as follows.

Water is added to the previously prepared raw materials at a temperature of 16-25 ° C until a fibrous suspension with a mass concentration of 6% is obtained. Cellulose grinding is carried out on a CRA apparatus at a rotation frequency of 150 ± 3 rpm for 10-25 minutes to obtain a degree of pulp grinding of 33-35 ° SR.

Microcrystalline cellulose obtained from plant materials by the non-hydrolysis method according to the invention according to the patent RU 2501325, publ., Is added to a pulp of ground sulfate softwood and sulfate hardwood pulp at their ratio 1: 1. 12/20/2013, in the form of a hydrogel containing 3% absolutely dry matter, in an amount of 5% to absolutely dry fiber of paper pulp. Then reagents are introduced to provide hydrophobicity to the paper: AKD in the amount of 0.05-0.15% and polyamide polyamine epichlorohydrin resin (PES) in the amount of 0.05-0.10% for absolutely dry matter to absolutely dry paper pulp fiber.

Laboratory prototypes of paper with a mass of 1 m ² 75 g are made on a Rapid-Keten sheet sintering apparatus at a pH of 7.8-8.0.

The obtained laboratory paper samples are tested according to the following indicators: capillary absorption of water in 10 minutes at a temperature of 23 ± 1 ° C, capillary absorption of liquid vegetable fats in 10 minutes at a temperature of 23 ± 1 ° C, fracture strength, breathability, elongation under tension, transformer oil grease permeability. Distilled water and unrefined sunflower oil “Sloboda” are used as test liquids. Comparative data on the test results are shown in Table 1.

The table shows that the introduction of the MCC hydrogel into the paper pulp in combination with AKD and PPE gives the paper increased strength, reduced air permeability due to a decrease in porosity of 1.5-2 times, in addition, ductility is increased, and zero capillary absorption is ensured liquid fats, increases the level of hydro-lipophobicity of paper.

Claims (1)

A method for producing hydrophobic and lipophobic paper using microfibrillar cellulose fibers, comprising pre-preparing raw materials from softwood and hardwood pulp taken in a 1: 1 ratio, preparing paper pulp by adding water to a pre-prepared raw material at a temperature of 16-25 ° C, preferably 16-20 ° C, to obtain a fibrous suspension with a mass concentration of 6%, grinding the resulting suspension on a CRA apparatus at a speed of 147-153 rpm, optimally 150 rpm, to obtain cellulose with a degree of mol 33-35 ° SR, composition by adding microcrystalline cellulose obtained from plant materials, preferably sugar beet pulp, to the resulting paper pulp in a non-hydrolytic manner, in the form of a hydrogel containing 3% absolutely dry matter, in an amount of 5% to absolutely dry fiber paper pulp, introducing an alkyl ketene dimer in an amount of 0.05-0.15% by absolutely dry matter to an absolutely dry fiber of a paper pulp and polyamide polyamine epichlorohydrin resin in an amount of 0.05-0.10% by absolutely dry matter to bsolyutno dry fiber pulp, paper manufacture samples listootlivnom apparatus with pulp pH 7,8-8,0.