Firma Carl Freudenberg

Herbert Arnold

Klaus Heckel

Gerhard Graab

Dieter Rischer

The invention involves the use of about 1 to 4 %wt cured elastomer irregularly-shaped particles having a sieve size of about 0.7 mm +/-0.1 mm in uncured elastomer to suppress bubble formation without substantial loss of tensile strength, in calendered, cured elastomer products, such as, decorative or sealing sheet materials.

Method for suppressing bubbles in calendered elastomer

A method of manufacturing a randomly patterned floor covering having contrastingly-colored zones from a preform of rubber in which the preform is cut in pieces, each of which are molded into a blank having projections extending from a top side of the blank in relief-like fashion, solidified by vulcanization and then machined by cutting only in the region of the projections. The rubber forming the contrastingly-colored zones is mixed with contrastingly-colored particles in an amount of at least ten percent by weight. These particles are substantially free of flat surfaces and are in, at least, an advanced state of vulcanization. The particles located in the projections extending from the top side of the blank are exposed during the cutting step.

Growing community of inventors

Morlenbach, Germany

Herbert Arnold