SU834295A1 - Composition for cardboard manufacture - Google Patents

Description

The invention relates to the production of various types of cardboard with a high content of filler, mainly boxed. It is known to use freshly molded polyvinyl alcohol fiber as a binder to increase the strength of fibrous materials. Polyvinyl alcohol fiber, 3-7 mm long, 5-15 microns in diameter, is metered into the fiber mass in the amount of 1-5% of its absolutely dry weight i. However, to achieve the required hardening of the material, significant costs of polyvinyl alcohol fiber are required, since not all possible connections between the polyvinyl alcohol and cellulose fibers are realized when the web is formed on the fibrous material. With the consumption of polyvine alcohol fibers, paper swelling is observed, as with the addition of any synthetic fiber, which reduces the effect of hardening the sheet fibrous material. In addition, at the expense of thermohydroplastic half-alcohol alcohol fibers above 0.5%, a paper web adheres to dry cylinders, which makes it difficult to use polyvinyl alcohol. fibers to increase paper strength. It is also known to use methylsrylamide copolymer and diethylaminoethyl methacrylate (amiflock) to increase the retention of the filler, the fine wavelength and other components of the pulp. High molecular weight cationic polyelectrolytes (} m1x with additions of 0.1-O, 5 wt. H. Causes intense micrO (}) to lock the paper pulp, which contributes to an increase in the content of the filler and the fine fraction of the fiber in the finished product 2. C & causes a drop in the strength indicators of fibrous cellulosic material in the sheet plane and especially in the normal direction, as there is a loosening of the structure

of the material, the number of interconnecting bonds is reduced due to the formation of a spatial barrier between the cellulose fibers.

Closest to the proposed product is a paper and paperboard composition containing May. h,: fibrous cellulose-containing semi-finished product 60-96.4, filler 0.535, curvature glue 0.5-1.5, alumina 1 / 2.5-3 and flocculant 0.1-0.5.

As a flocculant, the composition contains a water-soluble cationic product of copolymerization of methacrylamide and diztilaminoethyl methacrylate 3j.

 The use of the known composition for the manufacture of cardboard with a high f-content of the carrier does not ensure the production of cardboard with high rates of resistance to delamination.

The purpose of the invention is to increase the resistance of cardboard to delamination.

This goal is achieved by the fact that the composition for the manufacture of cardboard, mainly boxed, includes a cellulose-containing semi-finished product, padding agent, canine (; glue, alumina and flocculant, a copolymer of methacrylamide with diethylaminoethylmethacrylate, additionally contains freshly formed polyvinyl sulfate. 2O microns in the following ratio of components, May.

Cellulose

prefab11K: at1OO

Filler5-2 O

Rosin glue1-2

Alumina2-4

Flocculus nt0.05-0.15

Freshly formed polyshyl alcohol fiber 0.1-0.3.

The use of freshly formed polyvinyl alcohol fiber significantly increases the resistance of cardboard to delamination at a high content of scientific research institutes;

Components

80 8 O80 80 20 2020 201

15 52 O 15

by overcoming the spatial barrier between the fibers of the cellulosic material and the formation of additional melkolokonny bonds. In the pressing and drying process, these bonds can be transformed into adhesive-cohesive bonds between cellulose-containing and polyvinyl alcohol fibers.

With one-sided dehydration of the cardboard web, the filler is unevenly distributed over the thickness of the sheet, as a result of which the upper side of the sheet, having a higher content of filler, has lower strength characteristics. The introduction of freshly formed polyvinyl alcohol fiber, which has the ability to float in aqueous dispersions, ensures the achievement of uniformity of strength properties of cardboard and increases its resistance to delamination;

As a fibrous cellulose-containing semi-finished product, cellulose blephate can be used sulphite and sulphate (coniferous and leaf -wenna), wood pulp. ; Examples 1-3. Three experiments were carried out on the manufacture of boxboard at various ratios of the components of the composition. The composition is obtained as follows.

Polyvinyl alcohol fiber at a concentration of 0.2-0.5% is added to paper pulp containing filler, sizing agent and coagulant, to the machine pool, 0.1-0.5% flocculant solution (amiflock) is fed in the inlet ..

The mode of pouring, shaping and drying the cardboard does not change as compared with the current technological regulations.

In tab. 1 shows the known and proposed options for making

cardboard

Table 1.

Composition, May. h. 1 ha g 3 Tizvestny

- “Jliiiili.-1 I ..Jii | 1MI | YAI |

Continued table. one

Claims (1)

Claim Composition for the manufacture of cardboard; pre ²⁵ property boxes, including cellulose-containing; semi-finished product, (filler, rosin glue, alumina and flocculant - a copolymer of methacrylamide with diethylaminoethyl methacrylate, about ³⁰ tons different in that, with the aim of Indicators Composition Tensile Strength, MPa Resistance to delamination, MPa Resistance IZ- ₃₅ ^g scrap, the number of double bends Proposed 40 1 8.1 0.145 • 85 2 9.6 0.16 106 45 3 6.8 0.135 81 Famous 6.7 0.12 78 increasing the resistance to delamination of the cardboard, it additionally contains a freshly formed polyvinyl alcohol fiber with a length of 2-8 mm and a diameter of 7-20 microns in the following ratio of components May. hours: Cellulose-containing; semifinished 100 Filler 5-20 Gum rosin 1-2 Alumina 2-4 Flocculant 0.05-0.15 Freshly Forced polyvinyl alcohol fiber 0.1-0.3 ^fifty As can be seen from the table, the proposed composition provides an increase in the resistance of the cardboard to delamination, as well as an increase in the tensile strength and fracture resistance. ⁵⁵