CS220091B1 - ) Method of manufacturing rubber sheet products with different color design - Google Patents

Abstract

The subject of the invention is a method for producing rubber sheet products with a different colored pattern, especially vehicle mats, by jointly pressing a powder mixture in the pattern grooves of a mold and a flat cut from a different colored mixture. The essence of the method is that a partially vulcanized powder rubber mixture is used for pressing. So far, pressing of colored patterns from unvulcanized mixtures has been proposed. However, since the unvulcanized rubber mixture melts and sticks to the pressing mold, the mold must be cooled to a temperature lower than the melting point of the powder during each cycle before filling. This increases energy consumption and reduces the productivity of the device due to the extension of the working cycle time. According to the invention, a vulcanized mixture is used, i.e. a mixture crosslinked to the extent that it no longer sticks to the heated surface of the mold, which, however, still allows for vulcanization connection with the underlying mixture of the product by further heating.

Description

The present invention relates to the manufacture of rubber sheet articles having a color-different design by molding a powder mixture and a flat die cut in molds.

Color different designs of rubber products are required in those cases where the appearance of the product is to be maintained even after partial wear by abrasion and the like, where the surface decoration methods of a small layer of material are not entirely satisfactory.

The color design can be made, for example, by placing the strips on the base layer in a mold and pressing them. The method is laborious and cannot be used in mass production.

Another method is two-stage molding. In this process, a color mixture is first pressed into the mold with the aid of a punch, after opening the mold the residues are removed, the base mixture is introduced in the next step and the color parts are joined by vulcanization. The disadvantage is again the laboriousness and the fact that the adhesive residues of the mixture are difficult to remove from the mold and can cause visual defects of the product.

Simplification of the idea of the _FTS: method by which, in use třídílhé vulcanization mold insert each of the color mixture on the opposite sides of the middle part of the mold. During molding and vulcanization, both mixtures are pressed into the cavity of the middle mold part. The disadvantage is the difficult removal of the overflow to the molding of the compact.

·?. ·. Further, a method for producing color desks has been described based on the use of a powder mixture for the design of an article. The powder mixture is filled into the grooves of the lower mold part and, when closed, joined to the base mixture. Since the unvulcanized powder mixture melts and adheres to the mold, the bottom part must be cooled below the melting point of the powder at each cycle and reheated during compression. This increases the production cycle and increases energy consumption.

In order to overcome the above-described drawbacks, the process according to the invention has been developed, which is characterized in that the powdered rubber composition for the desoin part of the product is prepared by partially vulcanizing the desenic mixture and subsequently processing into a powder. A suitable powder for this technology can be prepared, for example, by partially curing the color mixture and grinding or grinding to the desired particle size. Under these conditions, the rubber structure only partially crosslinks and stiffens to such an extent that it no longer adheres to the heated mold surface. Thus, it is possible to omit repeated cooling and heating of the mold, thereby greatly increasing the productivity of the device. At the same time, however, the powder structure still permits vulcanization of the powder and the unvulcanized composition forming the substrate of the article, at a further vulcanization temperature of about 170 ° C.

In order to further elucidate the invention, the following exemplary embodiment is given.

For the production of design car mats, a primer mixture and a composition of the composition (in parts by weight) are prepared: -> · Base mixture:

Butadiene styrene rubber 100 ALIGN! Soot 100 ALIGN! Limestone 66 Bearing oil 22nd Paraffin 2 Stearin 1.3 Zinc white 2.2 N-cyclohexyl-2-benzthiazyl- sulfamide 1,8 Sulfur 3 Tetramethylthiuram disulfide 0.6 Design mixture (for red color): Natural rubber 80 Butadiene styrene rubber 20 May Precipitated silica 27 Mar: Zinc white 4 Paraffin 2.5 Stearin. 1,2 Antioxidant 1,2 Bis (benzthiazolyl) 2-2 disulfide 1.5 Tetramethylthiuram disulfide 0.5 Sulfur 1.7 Bearing oil, 3.2 rí Limestone 52 Titapová bílá 0.5 Red pigment 0.5

A 3.7 mm thick calender is pulled out of the base mixture on a four-roll calender and punched 525 x 525 mm.

The design mixture is drawn to a thickness of 10 mm, the 350 X 350 mm panels are partially cured at 150 ° C (7 min., 10 bar pressure) and dust is ground by grinding or milling.

The powder of the design mixture is filled into the grooves of the lower part of the vulcanizing mold, and a section of the foundation mixture is placed on the filled grooves. The lower mold part is inserted into a multi-stage press where the product is vulcanized after the mold is closed. The vulcanization is carried out at 170 ° C for 8 minutes.

Removal of the cylinder is immediately followed by another cycle without cooling the lower mold before refilling the powder mixture.

Claims (1)

SUBJECT A method for producing rubber sheet products having a different color design by co-pressing a powder mixture in the mold grooves of a mold and a flat die of a color different mixture, characterized in that the powder is a metallic rubber compound for the design portion. AND