1. The size of injection product is correspond with the size of injection mould, you can read the article named the determing method for the size of injection mold. It shows the relationship between the product size and injection mould size. In short,in order to assure the dimension accuracy of injection product, first to do is make sure the size of injection mould meet the accuracy requirement.

 

2. Plastic material has a great influence on the injection product. We should try to select the contract performance and stable material. Contractibility mainly contain thermal contraction of material, elastic recovery,plastic deformation, after-contraction, aging contraction etc.If the contractibility is unstable will lead to the product size unstable and quite big changes.

 

3. Injection moulding parameter. In the period of die trial, we should determine the correct and stable moulding parameter, and cannot adjust the injection molding parameter randomly. The change of moulding parameter will cause the corresponding change of product size.

 

4. Measure time. After injection moulding, injection prodcut should cooling completely and then to measure the size. To do that will make the size most accurate.