US2175568A - Manufacture of artificial building bodies - Google Patents

Description

1G6. COMPOSITIONS,

COATING R PLASTlC Patented Oct. 10, 1939 UNITED STATES Cross Reference PATENT OFFICE MANUFACTURE OF ARTIFICIAL BUILDING BODIES Karl Ewald Haustein, Berlin, Germany No Drawing. Application May 25, 1938, Serial No. 209,981. In Germany May 25, 1937 2 Claims.

My invention relates to a new method for the manufacture of artificial building bodies, such as blocks and plates.

In the art of manufacturing artificial building bodies, it is well-known to mix wooden chips, fir-tree needles, straw or a similar fibrous material with cement and to form stones or plates from this mixture. After the cement has hardened the arising bodies possess good heat-insulating and sound-insulating qualities, but they are pretty much liable to be brittle and to break into pieces.

I have discovered that highly solid and elastic artificial bodies, such as stones and plates, can be manufactured from the above-mentioned materials, if the said fibrous materials are partly digested by means of an alkaline treatment, then treated with an ingredient able to lower its waterabsorbing qualities, such as a clay-pulp, an alkaline glue, resin-milk, or the like, and finally mixed with cement.

The manufacture of my improved artificial bodies, may be carried out in the following manner: 200 kg. of rye-straw are boiled for about one hour in a lime-sodium lye of about 3 B. Now the partly digested rye-fibre material is withdrawn from the lye, laid upon a wooden grate, and rinsed with water in order to remove the surplus of lye adhering to said material. While the straw is still boiling in the lye, 100 kg. of clay and about 3 kg. of sodium silicate are mixed with some hundred liters of water and stirred to a smooth pulp which is free of clods. Now the partly digested and rinsed rye-straw material is introduced into said pulp, mixed and kneaded therewith. At the same time 300-350 kg. of cement are mixed in a separate receptacle with such a quantity of water that a pulp of creamlike consistency is obtained. After the clay pulp and the partly digested rye-straw material have been thoroughly kneaded with one another, the cement pulp is slowly poured into the mixture, this latter being continually kneaded during this time.

Now the mixture is introduced into open wooden molds, covered with a stamp-like lid, thoroughly pressed, and allowed to dry in its compressed state for a time of 3-4 days at the open air. In order to facilitate removal of the hardened bodies from the molds, the inner surfaces of the same may be rubbed with a fat or a soap or may be covered with paper.

I have discovered that, in order to obtain good results it is not sufficient to treat the fibrous materials used for instance with cold lime lye, or the like, but that it is necessary to effect a strong alkaline digestion by which the fibrous texture is partly broken up by a chemical decomposition of the albumen complexes and mercaptanes, contained therein. Furthermore, I have discovered that in order to obtain satisfactory results, it is not sufiicient to mix said partly digested fibrous material immediately with cement, but to treat it first with an ingredient such as clay adapted to lower the water-absorbing qualities without changing its alkalinity.

Only by depriving the fibrous material of all acidic and acidfying components and-by treating it with an ingredient lowering its water-absorbing qualities I have attained an insoluble firm union between the fibrous material and the cement, and as a result of this union 1 am able to produce blocks and plates which are substantially harder, more elastic and break-proof than the usual artificial stones and plates, the fibrous contents of which are only enclosed by the cemegt and not in an intimate connection there- W1 Although having described my invention only by way of one example, it will be obvious to one skilled in the art that many natural fibrous materials other than rye-straw may also be employed within the scope of my invention. Likewise, my invention is not restricted to the abovestated proportions of fibrous materials, cement and clay, it being obvious that other percentages also may be used in order to attain, for instance, an especially hard or an especially voluminous building material, the fundamental rule of my invention concerning a method of attaining a permanent connection between the cement and the fibrous material.

I claim:

1. A method of producing artificial building bodies, which consists in digesting fibrous material by an alkaline chemical treatment, rinsing the digested material, treating the digested and rinsed material with a substance adapted to lower its water absorbing quality, thereafter mixing said material with a pulp of cement and water, introducing the mixture into a mold, compressing the mixture within said mold and allowing it to dry under pressure.

2. A method of producing artificial building bodies which consists in partly digesting rye straw by treating it with lime-sodium lye, rinsing the digested straw material to remove surplus lye adhering to it, adding to the digested and rinsed material a water-clay pulp and thoroughly kneading the mixture, thereafter adding a pulp of cement and water to said mixture, introducing the mixture into a mold, compressing the mixture within said mold and allowing it to dry under pressure.

KARL EWALD HAUSTEIN.

Examiner