DE396137C - Process for the production of pulp from reeds, straw, corn cob leaves and similar material - Google Patents

Description

(ΟΊ2961

The raw materials for processing are dried well, then squeezed and then cut into pieces 2 to 3 cm long. The material thus crushed is sorted into two to three different types, each for further processing are fed.

The sorted material is pulped into baskets made of galvanized wire. The filled baskets are placed in cookers and covered with the liquor of 2 to ⁴⁰ Be prepared for the treatment. The treatment with the alkali is carried out either at a pressure of 5 to 6 atm for 1 to 3 hours or without pressure for 6 to 8 hours. After the leaching has ended, the baskets are taken out of the cooker and washed in washing tubs equipped with a stirrer and water intake and removal or washing machines.

If the material washed in this way is to be bleached, it is treated in a washing tub or in a Dutch oven for about ¹ Z ₂ to 1 hour with an acidic bath containing 0.5 to 0.6 parts of sulfuric acid or 0.7 to 0, for too parts of water. Contains 8 parts acetic acid.

The liquor used for treating the raw material is according to the invention as follows prepares:

First, a chlorinated lime solution of 2 to 4 ⁰ Be is prepared and, at the same time, a caustic alkali solution (soda, potash or ammonia soda) of 2 to 4 ⁰ Be is prepared in another vessel. After the two solutions have settled, they are mixed in such a proportion that there are 4 to 5 parts of chlorinated lime solution for 20 to 25 parts of caustic lye. An ammoniacal copper sulphate solution, which is composed of one part of copper sulphate and one part of ammonia, is added to the mixture thus obtained. Crudum consists of 200 parts of water, namely a part of the ammoniacal copper sulphate solution is used for .120 to 130 parts of the above-mentioned chlorinated lime solution.

The material treated with the lye produced in this way and then washed is used as a V4 bleached product for inferior papers while it is used for manufacturing Better types of paper are treated in an acid bath, as indicated.

The lye used can be used 5 to 6 times. The amount consumed will replaced after each leaching process. After 5 or more uses, the lye is drained off and recovered by regeneration (evaporation and calcination). The yield according to the new process is about 30 to 40 percent of the dry raw materials. Since the implementation of the Process serving alkali is used about 5 to 6 times in succession, with the low If the lye is always replaced by fresh lye, the costs for the production of the pulp are significantly reduced, because the need for leaching agents

is 50 to 60 percent less than with the previously known processes.

Claims (1)

Patent claim : Process for the production of cellulose from reeds, straw, corn cob leaves and similar material for the purposes of paper manufacture, characterized in that the dried, short cut, dedusted and sorted material is treated with or without pressure in a lye, which is a mixture of a caustic Alkali solution (from about 2 to 4 ⁰ Be) and a chlorine lime solution (from about 2 to 4 ⁰ Be), to which a small amount of an ammoniacal copper sulfate solution (about 1 part ammon. Crudum, 1 part copper sulfate, 200 parts water) is added.