Matters needing attention when selecting raw materials
(1)The linear expansion coefficient of the plastic is generally larger than that of metal, some of which are easy to absorb water, so the size changes greatly. Clearance and clearance must be considered according to the selected plastic types in mold design Tolerance.
(2)Various kinds of plastics have certain range of strength and allowed to contact media, which should be considered when selecting.
(3) from plastic, such as PC, PS, etc, they have the stress cracking phenomenon, try to minimize stress in the design and injection. When the design to avoid stress concentration, strictly control the processing technology and appropriate post-processing.
The thermal conductivity of waste plastics is generally low, which must be fully considered when selecting and designing the cooling system.
Some plastics tend to creep and retract or deform, and should be carefully selected and designed.