DE715890C - Process for the production of low-resin wood pulp from pine wood - Google Patents

Description

Process for the production of resin-resistant wood pulp from pine wood. "'Used in the processing of wood for wood pulp and its further processing to paper as a raw material not, as was usually the case up to now, the low-resin spruce wood, but related to pine wood, its high resin content has an effect during the Processing, in particular -in grinding, sorting., Sieving and pressing, very annoying.

It has been suggested - the sanding of pine wood '' with simultaneous treatment with alkali compounds such as soda, caustic soda and the like: Ä .; to make a saponification of the H2, rzes -, or else deni resin "the stickiness due to the addition of alkaline earth compounds such as barium hydroxide or other water-soluble barium compounds or alkaline earth chlorides, if appropriate with simultaneous or prior application of alkali solutions, largely to to take. However, there are various disadvantages when using this method: -The wood pulp can be caused by the dark-colored saponification products that are formed. experience an undesirable change in color tone - (yellowing), and it can-during-that Abrasive excessive foaming occurs as a result of saponification of the resin; which is particularly evident in the further processing of the wood sanding on the paper machine makes disturbing noticeable. - '-j # s - a procedure has now been found that can be used in the - Processing of pine wood "", to wood pulp and further to paper the * itself renders the precipitating resin harmless in a simple manner, 3 but that of the known ones Process does not have any disadvantages.

According to the invention, the pine wood is used during or after processing by Grinding z. B. in the vicinity of the grinding point alkali metasilicate in small amounts., either as a powder or as an aqueous solution, added. The success of this treatment is apparently due to the fact that the resin is emulsifying by the acting Alkakmetasilat is largely dispersed. in this finely divided It goes almost completely into the wastewater and becomes the wood pulp withdrawn. This changes the pH of the wood pulp, which is between d and 5 only insignificant. In this procedure is above all. the preservation of its own color of the cut is guaranteed, because saponification of the resin with its rest is disadvantageous Consequences is avoided. The otherwise due to the stickiness of the Harzes observed troublemakers in the further course of the manufacturing process, because yes the resins from the wood by treatment with alkali @ inetasilicate largely are away.

Of course nothing stands in the way; to be used according to the invention Alkali metasilicate still small proportions of the known, mentioned at the beginning, for elimination to add compounds leading to the tackiness and saponification of the resins.

Optionally, m'ari can be made from the resin and the sodium metasilicate containing wastewater by adding .. metal salts, e.g. of alkaline earth metal chlorides, Aluminum sulfate, zinc sulfate, among others, the resin and the silicate in whole or in part separate and, for example, continue to use as a filler for the paper pulp.

It has also been suggested when making wood pulp Sodium silicate in the form of water glass to the water supplied at the grinding point or other salts of inorganic or organic nature or aqueous emulsion, consisting from organic fat solvents, wetting agents or Q.uellton, to be added. These However, procedures are for the removal of I stains. from one from resin-rich. Pine wood pulp cannot be used because of the proposed solutions or female emus - either not the resin at all or only to a minor extent dissolve or colloidal. bring into solution.

Although it is also known to use alkali metasilicate for cleaning To use felts, rags, sieves, waste paper, etc., but this is not in any We have shown a way to produce low-resin wood pulp from pine wood.

The method according to the invention has opposite to the introductory discussed known processes still have the particular advantage that the resin-containing Pine wood can be sanded both cold and hot, d. H. on a Cooling of the grinding point can, if necessary, have no negative consequences for the ground joint be waived. For the extraction of some processed products but the use of wood pulp produced by hot grinding is of particular importance to.

Examples: `By means of a suitable device, a sodium silicate solution is continuously produced sprayed onto the grindstone just in front of the grinding zone, the amount of which is regulated in this way is that for every 100 kg of dry wood pulp produced, about 1 kg of sodium metasilicate is consumed. "The pH of the ground glass without the addition of sodium metasilicate 4., 3 is hardly increased, while the resin content, which was before the addition of the sodium metasilicate 2.50% is o, after the addition of the same is reduced to o.60%. This extensive Reducing the resin content causes foaming «during grinding is only small and that- also when processing the mass on the paper machine Disturbances as a result of resin deposition or Scliaumbilung do not occur.

2 .; Powdered sodium silicate becomes continuous while grinding sprinkled on the wood to be processed on the grinding parts, namely in such Quantities that for every 100 kg of dry wood pulp produced about 1 k .g of sodium tetasilicate Application comes. The ground joint obtained has a px value. of 5 and one Resin content of 0.5%. The cut resulting from the slight formation of foam leaves continue to process flawlessly.

Claims (1)

PATENT CLAIM: Process for the production of resinous fibers. Wood pulp made of pine wood, thereby. geckig, draws, that the wood during or after processing by grinding, e.g. B. near - near the grinding point, alkali @ metasilicate in small Amounts, either as a powder or as an aqueous solution, is added.