Color classification of silicone products

In addition to the superior product performance, silicone products also have a unique advantage that is the color change. A good product is first from the outside to the inside. Many people want to see the actual use of the product and also require appearance. There are certain standards. Most consumers are concerned about the appearance of the product, so it is naturally very important for the appearance of silicone products.

Solution coloring
The method is to dissolve the silicone rubber with a good solvent into a certain concentration solution, then add the colorant and the silicone rubber compounding agent other than sulfur to the solution, stir and mix uniformly, remove the solvent at a certain temperature, and finally refining Add sulfur to the melter. The operation is complicated, the dispersion is uneven, there is color difference, the solvent is difficult to recover, the environment is polluted, and it is rarely used.

Kneading
This method is currently the most commonly used method for coloring silica gel products. The colorant is directly added or mixed with the carrier before being added to the rubber compound, and mixed by a rubber mixer to color the silicone rubber. Specifically divided into the following methods.

Dry powder coloring

The powdery colorant is directly added to the silicone rubber together with the small materials, and mixed on an open mill. The advantages are simple operation and low cost, but the dust is large during mixing, pollutes the environment, and it is not easy to disperse uniformly, and there is chromatic aberration. If the particles are too hard and coarse, it will also cause quality problems such as color point, stripes, or mutual pollution of chromatography. .

Color paste

First, the colorant is mixed with a liquid compounding agent (such as a plasticizer), ground with a three-roller mill to make a paste or slurry, and then added to the silicone rubber and mixed according to a certain ratio. This method can avoid dust flying, which is beneficial to disperse the colorant in the rubber, and the color is uniform. However, the content of the colorant in the color paste is low, the coloring is not high, the transportation volume is large, the loss is large, and the user is inconvenient to use.

Pellet coloring

There are two main methods for preparing colorant pellets. The first method is the same as other powdery compounding agent granulation methods. The powdery colorant is first soaked with a surfactant, and then granulated by wax melting or melt extrusion with a resin. The second method is to use a colorant After the surfactant is infiltrated, the colorant particles are refined by mechanical force to make a dispersion with a certain concentration, which is then mixed with the latex and co-settled. After drying, it is rolled into pellets. The granular colorant is convenient to use, has good dispersibility, no dust flying, does not pollute the environment, bright color, uniform hair color, and no color difference. It is a promising coloring method. However, the granular colorant has a complicated preparation process and high cost, which limits its wide application.