SU440468A1 - Paper weight - Google Patents

Description

one

This invention relates to pulp and paper production.

Known paper pulp for the manufacture of containerboard based on fibrous components.

However, the fibrous materials used in the manufacture of containerboard are quite expensive.

The purpose of the invention is to reduce fiber consumption and improve the physical and mechanical properties of cardboard.

This is achieved by the fact that the paper pulp additionally contains activated sludge from biological wastewater treatment plants of pulp and paper production in the following ratio of components, weight. %: Fibrous components 80-95

Active il 5-20.

Activated sludge directly from biological purification facilities with a concentration of 0.5-3.0% is added in the amount of up to 20% by weight of absolutely dry fiber to the ground and glued pulp entering the mixing pump. Next, the resulting mass is ejected and the entire further process proceeds in the usual mode.

The use of activated sludge in the manufacture of paper pulp saves expensive fiber raw materials and at the same time reduces the cost of wastewater treatment.

Example 1. Unbleached sulphate pulp is ground in a roll to 24 ° F, glued by rosin glue to precipitate glue particles of alumina (in the usual sizing mode). Before casting, excess activated sludge from biological treatment facilities is added to the mass. The sludge concentration is 20 g / l. Excess activated sludge is introduced into the mass in a ratio of absolutely dry fiber of 5: 95%. Samples of cardboard weighing 200 g / m and 260 g / m are cast on the Rapid-Keten apparatus. At the same time, the resistance to punching and ring compression of the cardboard of the first weight is 8.1 kgf / cm and 2.51 kgf / cm, respectively, with the same indicators of the sample of paperboard not containing activated sludge - 6.9 kgf / cm and

2.51 kgf / cm, respectively.

In the case of a sample of cardboard weighing 260 g / m, the same indicators are 9.95 kgf / cm and 3.38 kgf / cm, respectively, provided that the initial sample had resistance to bursting of 9.2 kgf / cm and ring compression 3, 4 kgf / cm.

Example 2. The raw materials are the same as in example 1, the components are prepared in a known manner. Excess active sludge

is introduced into the mass in a ratio to the weight of absolutely dry fiber 10: 90%. The cardboard is also cast with a weight of 200 g / m and 260 g / m. The resistance to punching and ring compression of a 200 g / m sample is 8.03 kgf / cm and 2.60 kgf / cm, respectively; sample weighing 260 g / m - 10.1 kgf / cm and 3.46 ngs / m, respectively.

Example 3. Components prepared in a known manner. The ratio of activated sludge and absolutely dry fiber is 15: 85%. Samples of cardboard weighing 200 g / m have resistance to bursting of 8.74 kgf / cm and ring compression of 2.63 kgf / cm; samples weighing 260 g / m - 9.9 kgf / cm and 3.5 kgf / cm, respectively.

Example 4. Components prepared as in example 1. The ratio of excess activated sludge and absolutely dry fiber

20: 80%. A 200 g / m sample of cardboard has a burst resistance of 7.9 kgf / cm, a ring compression of 2.58 kgf / cm2; sample weighing 260 g / m. - 10.8 kgf / cm and 3.4 kgf / cm, respectively.

The test results of cardboard samples showed that using cardboard in the composition, 10-15% of surplus activated sludge makes it possible to obtain products of better quality; resistance to punching and ring compression of a sample of cardboard containing sludge will increase by 16-26% and 4%, respectively.

In tab. 1 shows the strength properties of a known cardboard weighing 200 g / m and the proposed cardboard, containing 10-15% of its active sludge.

Table 1

The strength characteristics of cardboard with the addition of activated sludge comply with the requirements of GOST 7420-69 and are not lower than those of samples of cardboard not containing activated sludge. In tab. 2 shows the qualitative characteristics of the known and proposed masses.

table 2