Commonly used plastic coloring methods

When light acts on plastic products, part of the light is reflected from the surface of the product to produce luster, and the other part of the light is refracted and transmitted into the interior of the plastic. When encountering pigment particles, reflection, refraction and transmission occur again, and the displayed color is the pigment. The color reflected by the particles.

Commonly used plastic coloring methods are: dry coloring, paste colorant (color paste) coloring, color masterbatch coloring.

1. Dry coloring
The method of directly using toner (pigments or dyes) to add an appropriate amount of powdery additives and plastic raw materials for mixing and coloring is called dry coloring.
The advantages of dry coloring are good dispersibility and low cost. It can be arbitrarily specified according to needs, and the preparation is very convenient. It saves the consumption of manpower and material resources in the processing of colorants such as color masterbatches and color pastes, so the cost is low, and buyers and sellers do not need to use it. Restricted by the amount: The disadvantage is that the pigment will have dust flying and pollution during transportation, storage, weighing and mixing, which will affect the working environment and the health of operators.
2. Paste colorant (color paste) coloring
In the paste coloring method, the colorant is usually mixed with a liquid coloring auxiliary (plasticizer or resin) to form a paste, and then it is evenly mixed with plastic, such as color paste for sugar glue, paint, etc.
The advantage of pasty colorant (color paste) coloring is that the dispersion effect is good, and dust pollution will not be formed; the disadvantage is that the amount of colorant is not easy to calculate and the cost is high.
3. Masterbatch coloring
When preparing color masterbatch, the qualified color pigment is usually prepared first, and then the pigment is mixed into the color masterbatch carrier according to the formula ratio. The particles are fully combined, and then made into particles similar in size to resin particles, and then used for molding equipment to make plastic products. When used, only a small proportion (1% to 4%) needs to be added to the colored resin to achieve the purpose of coloring.

References
[1] Zhong Shuheng. Color Composition. Beijing: China Art Publishing House, 1994.
[2] Song Zhuoyi et al. Plastic raw materials and additives. Beijing: Science and Technology Literature Publishing House, 2006.
[3] Wu Lifeng et al. Masterbatch User Manual. Beijing: Chemical Industry Press, 2011.
[4] Yu Wenjie et al. Plastic Additives and Formulation Design Technology. 3rd Edition. Beijing: Chemical Industry Press, 2010.
[5] Wu Lifeng. Design of plastic coloring formula. 2nd edition. Beijing: Chemical Industry Press, 2009