How to Change the Hardness of Plastics?

1.The concept and indication of hardness

Hardness is the ability of a material to resist the pressure of other hard objects into its surface.

The hardness value is a conditional quantitative reflection of the hardness and softness of the material, and it is not a simple and definite physical quantity. The hardness value depends not only on the material itself, but also on the testing conditions and methods. Therefore, in order to compare the hardness between materials, the hardness measured by the same measuring method is comparable.

 

The following methods are commonly used to indicate hardness:

a. Shaw hardness

b. Rockwell hardness

c. Morse hardness

 

2.Improve the hardness of plastics by blending

Improve the hardness of plastics by blending is to blend high-hardness resin with low-hardness resin to improve its overall hardness. The common blend resins are PS, PMMA, ABS and MF, and the main resins in need of modification are PE, PA, PTFE and PP etc.

 

3.Improve the hardness of plastics by composite modification

Another method of improving the hardness of plastics is to compound a layer of high-hardness resin on the surface of low-hardness plastic products. This method is mainly suitable for extrusion products, such as plates, sheets, films and pipes. The commonly used composite resins are PS, PMMA, ABS and MF etc.

 

4.Improve the hardness of plastic surface

This method only improves the hardness of plastic surface, while the hardness of the products inner-side remains the same. This is a low-cost hardness improvement method.

This modification method is mainly used for shell, decorative materials, optical materials and daily necessities. This modification includes coating and surface treatment.