As we all know, most of the pure resin properties of polymers can not be used directly, and they need to be modified to meet the needs of products. What we often call modified plastics is to change the original properties of plastics through some physical and chemical methods, increase or improve their original properties, and make them more suitable for terminal products.

8 major directions of plastic modification: haze, density, hardness, processability, strength, toughness, thermal properties and flame retardancy
As for the haze value of modified plastics, it can measure the transparency of plastics. Commonly used indicators include transmittance, refractive index, birefringence and dispersion. A good transparent material requires the above performance indexes to be excellent and balanced.
The commonly used methods to change the haze of plastics are:
① Control crystal quality, such as crystal form, spherulite content, crystal size and crystal regularity.
② The refractive index is improved mainly by adding high refractive index organic or inorganic substances that do not affect the transparency.
③ To reduce the birefringence, the birefringence can be reduced by controlling the orientation in processing, that is, reducing the degree of orientation.
④ Adding to improve the transparency of plastics refers to the method of adding small molecular substances into transparent resin to improve its transparency. Using this method, the transmittance and refractive index can be improved and the birefringence can be reduced.
⑤ Adding nucleating agent is the most effective way to increase the transmittance of transparent resin. Nucleating agent is a small molecular substance that can promote crystallization. It can play the role of crystal nucleus in the resin, turn the original homogeneous nucleation into heterogeneous nucleation, increase the number of crystal nuclei in the crystallization system, increase the number of microcrystals and reduce the number of spherulites, so as to reduce the crystal size and improve the transparency of the resin.
⑥ Adding inorganic substances with high refractive index
⑦ Add substances that can reduce birefringence
⑧ Add antifogging agent
Haze is also known as turbidity. The degree of clarity of transparent or translucent materials is expressed as a percentage of the ratio of scattered luminous flux to luminous flux of transparent materials. Transmittance is expressed as a percentage of the ratio of the luminous flux of the material to the incident luminous flux.

Haze is the upper transmission light of wide-angle scattered light (scattered light with an angle of ＞± 2.5 ° in the integrating sphere), that is, all green parts in the integrating sphere in Figure 2 are higher than all red parts in the integrating sphere in Figure 1; Transmittance is the ratio of transmitted light (that is, all red parts in the integrating sphere in Figure 1) to incident light (that is, all blue light before passing through the sample)
After the haze value of modified plastics is changed, it is necessary to measure the haze value to ensure that the transparency of products produced meets the actual use standard. Then you need to use a professional instrument - Hazemeter to detect.