With the advancement of technology, silicone products are no longer as monotonous as they used to be, and various products are available in different colours in the market, but as a result, there are many purchasing friends who have questions about the colourful silicone products, such as the quality of its colour.
But for those who do not know much about silicone products, do you know how silicone products are coloured? Do you know its safety performance?
How is the silicone coloured?
Silicone raw material is transparent, colourless and tasteless, it is a highly living material with strong adsorption properties and does not conflict with any substance except strong alkalis. But because silicone raw materials must be kept in a variety of styles during the production process, it appears to have many options, so silicone product manufacturers generally use masterbatches to add a variety of colours to it, to keep its appearance from being single. Silicone masterbatches are formed by gathering silicon raw materials, silicone oils, colour powders and dispersants. The reason why we choose to use silicone masterbatches to make silicone products is because they are stable, highly dispersed and evenly used on top of the product, environmentally friendly, non-toxic, non-polluting and do not expire when stored for a long time.
Silicone masterbatch is an indispensable item for silicone product manufacturers, and its main process is to be used in the rubber refining process. The colour of silicone masterbatch needs to be carefully adjusted to achieve good results, and is an important technical task for silicone manufacturers. It is a very important technical task for silicone manufacturers. The better the heat resistance, the higher the dispersion force, and the higher the dispersion force, the more uniform the colour distribution of the products.
In addition, the colouring of silicone products has several colouring methods as follows.
The method is to dissolve the silicone rubber into a certain concentration of solution with its good solvent, and then add the colouring agent and the silicone rubber matching agent other than sulphur yellow into the solution and mix it well, dry it at a certain temperature to remove the solvent, and finally add sulphur yellow on the rubber making machine. The operation is complicated, the dispersion is not uniform, there are colour differences, the solvent is difficult to recover, pollute the environment, less used.
- Mixing method of colouring
This method is the most commonly used method of colouring silicone products, is to add the colouring agent directly or first mixed with the carrier and then added to the rubber material, through the mixing machine to mix evenly, so that the silicone rubber colouring. The specific methods are as follows.
The powder colouring agent is added directly to the silicone rubber together with the small material and mixed on the open refiner. The advantage is simple operation, low cost, but the mixing of dust, pollution, and not easy to disperse evenly, there are colour differences, if the particles are too hard and too coarse, but also cause colour spots, stripes or chromatographic pollution and other quality problems, less used.
The colouring agent is first mixed with a liquid compound (such as plasticiser), ground into a paste or slurry with a three-roller machine, and then added to the silicone rubber in a certain proportion and mixed. This method can avoid dust flying and facilitate the dispersion of the colouring agent in the rubber and uniform colour. However, the content of colouring agent in the colour paste is low, the colouring is not high, the transport volume is large, the loss is large, and it is not convenient for users to use.
There are two main methods of preparing colourant granules. The first method is the same as other powdered matching agent granulation method, first the powdered colorant with surfactant infiltration, and then by wax melt or extrusion with resin melt granulation; the second method is the colorant with surfactant infiltration and then by the action of mechanical force to make the colorant particles fine, made of a certain concentration of dispersion, and then mixed with latex co-sink, after drying rolled sheet granulation. Granular colorants are easy to use, good dispersion, no dust flying, no pollution of the environment, bright colour, uniform colour, no colour difference, is a very promising coloring method. However, the preparation process of granular colouring agent is complicated and the cost is high, which limits its wide application.