SU66867A1 - Method for increasing water resistance of cardboard - Google Patents

Description

The main disadvantage of shoe cartons is their low water resistance, which results in a drop in the strength of the paperboard in the wet; state, easy abrasion and change its shape in the process of exploitation.

To eliminate this drawback, many different methods have been proposed, based on the use of sizing or impregnating materials, which is associated with the additional operations of preparing adhesives, which increase the cost and give a temporary effect, destroying P1, ijc in the process of exploitation.

The proposed method does not require additional consumption of materials and consists in the heat treatment of cardboard at a temperature of 130-150 ° C for a relatively short time (about one hour).

Similarly, “quenching of cardboard, depending on its composition by fiber, increases the water resistance from 50 to 90%, increases abrasion, and also significantly improves all indicators of the resistance of wet cardboard by physicomechanical effects.

The application of such heat treatment to cardboard, glued using rosin glue in the usual way, allows to produce cardboard with a wetness well below the standards established for the respective type of cardboard, with high wetting and good abrasion resistance.

The quenching of non-glued cardboard, together with the latter, such a large increase in water resistance, which makes it possible to use it along with normally glued, has an even greater effect.

The established effect of heat treatment of cardboard, both glued and not glued, is characterized by the fact that it is not superficial and does not decrease due to repeated bending and repeated soaking and drying of cardboard. The physicomechanical properties of dry paperboard change slightly as a result of this heat treatment, only water resistance greatly increases and, therefore, the resistance of mechanical forces in the wet state increases.

It has been found that the cleaner the pulp, the more waterproof it becomes after heat treatment. Indicators of the influence of the thermal “oakalka on the wettedness of the special board are given in the table: Fictional labor. A significant increase in wet rolling resistance gives

The proposed method of "hardening cardboard allows you to significantly increase the analytical" exploitation of the quality indicators of cardboard, as well as for many varieties, so to: reduce, and in some cases, it (D1H: or change sizing materials. This measure only reduces About ProductionSHOMOCTb (Products, io eliminates the consumption of scarce natural or artificial C1mo.l and other substances. In addition, this eliminates the need for cooking adhesive solutions and IB associated with this operation, an additional qualification to refuse the application cardboard and cloth.

The increased consumption of electricity or steam to warm up the cardboard (or finished backs) is compensated for by reducing the choice of rollers in which mass is glued.

Subject invention

A method of improving the water resistance of cardboard, wherein the non-glued or glued cardboard is heat treated at a temperature of 130-150 ° C. IB for about 1 hour.