Nowadays, many synthetic polymers are available, and each polymer has its own unique characteristics. Some are resistant to impact, some are more resistant to ultraviolet rays, and some are flexible. This should be known before the injection molding production and processing project starts, so as to select suitable materials.
There is a whole set of scientific knowledge about how adding color to plastics affects the behavior characteristics of plastics. In this paper, the influence of colorants on plastics was studied.
Compatibility
When developing a colorant package for any polymer, it is important to consider the compatibility between the polymer chemical composition and the colorant chemical composition. Some compounds in colorants will destroy the chemical properties of polymers and weaken their original characteristics. High temperature in injection molding also affects colorants and polymers.
Quantity of colorant
The performance retention of the polymer is also a function of the amount of coloring agent incorporated into it. Adding 1-2% colorant is usually harmless. With the increase of colorant content, the greater the chance of plastic properties changing.
Different colors, different attributes
Transparent colors can be made from dyes, which may have less influence on polymer structure than pigments used in opaque colors. Pigments are composed of particles, and the size of these particles will affect the properties of materials. Molding the same part in different colors actually leads to different dimensions of the part.
Colorant incorporation method
There are several different methods of coloring plastics, including masterbatch, composite, surface coating and dry mixing. They have their own advantages and disadvantages, and they are different in cost, color consistency and other factors. The coloring method used will affect the mechanical properties of plastics. For example, in a color masterbatch, a naturally colored pellet is mixed with a pellet "color masterbatch" having a high pigment content. Since most polymers do not mix well with other polymers, care must be taken to ensure the compatibility of materials, otherwise mixing may lead to problems.
In a word, the effect of colorants on injection molded parts is much more complicated than we think, and it is usually not the primary consideration when planning injection molding projects. However, it should not be ignored and should be paid attention to in the stage of material selection.
