DE696391C - Process for the production of molded bodies, in particular plates - Google Patents

Description

Process for the production of moldings, in particular panels Es processes are known in which fibrous materials, in particular wood fibers, are more aqueous Porridge formed into a water-containing body and then under heat and pressure into one solid, anhydrous bodies are pressed. Usually additional binders are used used here, because it has been shown that the natural incrustations of the fibers do not bring about binding of the fibers, which the finished products sufficiently make water resistant.

The present process for the production of moldings, in particular Plates, by deforming an aqueous slurry of encrusted fibers, in particular Wood fibers, and hot pressing of the thus obtained still; wet moldings is thereby characterized in that the wet molded fiber articles in the presence of phenols, phenol-containing Mixtures, substances that split off phenol or compounds with a phenolic hydroxyl group under pressure and heat and preferably in the presence of accelerators which the 'Promote condensation with the natural fiber components, press until the adhering water is squeezed out and evaporated. According to the invention are accordingly the phenols either added to the wet pulp layer or the molded wet one Body, for example a plate, incorporated, for example, by suction. Among phenols, mixtures containing phenol, substances that split off phenol or compounds with phenolischea- Hydroxyl groups should not be understood to mean any phenol-aldehyde initial condensation products be.

The new process has the major advantage that the natural Fiber lubricants completely or partially converted into adhesive condensation products which better, connection and very water-resistant putty of the Cause fibers. This chemical reaction is not only due to the high temperature, but also the counterpart of water is required.

The result was surprising, as it is known that wood in contrast to lignin when treating with phenols, no synthetic masses that can be used for hot pressing results. In the case of the method according to the invention, then, the favorable result is evidently attributed to the presence of water during compression.

You already have wood sawdust with an excess of phenol and larger amounts of mineral acid, e.g. B. sulfuric acid. Allow each other to act and here, depending on the reaction temperature, liquid, plastic or solid obtained resinous condensation products. In this process, however, the Cellulose of wood undergoes profound decomposition and completely loses its fiber structure, while in the present invention the cellulose of the fiber is none noticeable Change .erlebt, so that for the structure and the porosity of the molded body valuable matting is preserved, ..

Finally, it is also known to produce phenol-aldehyde initial condensation products in an aqueous wood fiber pulp to add, to shape the paste, to dry the moldings and then to press hot. Apart from the fact that the gluing of the fibers is mainly caused by the Phenol-aldehyde condensation product occurs while in the present process the cementing of the fibers essentially from: the action of phenols, mixtures containing phenol, substances that split off phenol or compounds with phenolic The sticky hydroxyl group formed on the fiber incrustations, especially lignin Based on reaction products, one gets by the process according to the invention without prior drying of the fiber mass and without using aldehyde to produce products of good mechanical properties. Example one made from iookg wood pulp and zoool water is produced by draining, suction and squeezing formed into a matted wet fiberboard. This plate makes a 7% aqueous phenol solution sucked. This plate is then placed in a hot plate press the iF #. effect of pressure and heat u: nerwor-; y'um die. Reaction between the Phenol, the incrustations and the drying of the plate. For the production a hard plate is expediently used a pressure of about 5okg / sqcm and a Temperature of about i 5o '.

Claims (1)

PATRNTANSPRUCII: Process for the production of moldings, in particular Plates, by deforming an aqueous slurry of encrusted fibers, in particular Wood fibers and hot pressing of the still wet moldings obtained in this way characterized in that: the wet molded fiber articles in the presence of phenols, phenol-containing; gen Mixtures, substances that split off phenol or compounds with a phenolic hydroxyl group under pressure and heat and preferably in the presence of accelerators which the Promote condensation with the natural fiber components, press until the adhering water is squeezed out and evaporated.