The coloring methods of rubber products are mainly surface coloring and mixing coloring. Surface color is to spray the coloring agent to the surface of rubber products to make rubber products colored. The method has a certain effect on static products, for dynamic products, the colorant is easy to peel off, easy to fade. Mixture coloring is the main method of rubber coloring at present, divided into solution method and mixing method of two, which mixing method and dry powder coloring, slurry coloring, grain coloring and mother refining rubber color and other methods.

Solution coloring

The method is to dissolve the rubber with its good solvent into a solution of a certain concentration, and then add the colorant and rubber coordination agent in addition to sulfur into the solution to stir and mix evenly, dry at a certain temperature to remove the solvent, and then add sulfur on the rubber mixer. The operation of this coloring method is complex, colorant and coordination agent dispersion is not uniform, color difference, solvent recovery is difficult, pollution of the environment, has been less used.

Blending coloring

This method is the method often used for coloring rubber products at present. It is to directly add the colorant or first mix it with the carrier and then add it to the rubber material, and mix it evenly through the rubber mixer to make the rubber colored. The specific methods are as follows.

Dry powder coloring this method is directly the powder colorant with small material together with rubber, mixing in the opening machine. The advantages of this method are simple operation and low cost, but when mixing, the dust is large, polluting the environment, and it is not easy to disperse evenly, with color difference. If the particles are too hard and coarse, it will also cause quality problems such as color spots, stripes or chromatographic mutual pollution. In order to facilitate the use of powder colorants and stearic acid, sulfate and other pre - dispersed colorants made of the market has been sold.

Mother refining glue color

This method is to first color agent, part of the plasticizer and other rubber with raw rubber through the mixing machine made of about 50% of the concentration of color agent mother rubber mixing, and then proportioning to the rubber coloring. This method for fine particles, difficult to disperse colorant coloring is more effective, uniform hair color, no chromatic aberration. When cooperating, pay attention to the concentration of coloring agent in the mother refining glue and deduct the amount of other coordinating agent in the mother refining glue.