I. Definition of plastic color matching:
Definition: color matching is in red, yellow, blue (three primary colors) on the basis of three basic colors, with a favorite, in line with the requirements of the color card color difference, in line with the customer hope to get the color, economic and in processing, use color.
In addition, plastic coloring can also give plastic a variety of functions, such as improving plastic light resistance and weather resistance;
Give plastic some special functions, such as electrical conductivity, antistatic, antibacterial properties and other special materials;
Different color mulch film has the effect of weeding or avoiding insects, seedling and so on.
That is, through color matching can also achieve certain application requirements.
Ii. Colorant:
Pigments and dyes
Pigment characteristics: Pigments are colorants that cannot be dissolved in common solvents. Therefore, to obtain ideal coloring properties, it is necessary to disperse pigments evenly in plastics by means of mechanical heating and mixing.
Pigments are classified into organic pigments and inorganic pigments according to their structure.
Inorganic pigments:
Advantages: good thermal stability, very good weather resistance, excellent light stability, low price, excellent dispersion performance.
For example: titanium dioxide, carbon black and so on.
Titanium dioxide series: there are mainly three kinds of titanium dioxide, zinc oxide and zinc barium white.
Titanium dioxide rutile type and anatase type two types of structure, rutile type titanium dioxide refractive index is high, high covering power, stability, good weather resistance.
If titanium dioxide is not dispersed when the original factory leaves the factory, there will be a large number of black spots in the color matching process, which belongs to the state of dispersion and is not opened. Therefore, dispersant is needed for dispersing processing before it can be used. Some brands of manufacturers enter the market after processing, and such materials can be directly used.
Mainly used to cover the transmittance of resin and increase the whiteness.
Carbon black: it is a commonly used black pigment with low price. In addition, it has ultraviolet protection (anti-aging) effect and electric conductivity effect on plastics. Different production processes can get a wide range of different carbon black particle sizes, with very different properties.
According to the use of carbon black is divided into pigmented carbon black and rubber reinforced with carbon black, according to its coloring ability is divided into high pigmented carbon black, medium pigmented carbon black and low pigmented carbon black.
Carbon black particles are prone to aggregation. To improve the coloring power of carbon black and to solve the dispersion of carbon black, dispersants should be added for processing before use.
Disadvantages: relatively poor coloring, relatively high density, large amount of addition, not bright color;
Mainly used in: used to increase the color concentration (according to the color needs generally all kinds of resin can), especially in engineering plastics has a good superior performance, such as: PA, PC, PBT, POM, PPO, PPS and other materials and non-transparent color, gray resin.
