* Core-pulling and slide of injection mold
1. When plastic parts cannot be separated smoothly according to the mold opening direction, core-pulling and slide should be designed. Core-pulling and slide can help mold products with complex structure; but it is also easy to cause the defects such as flat-fell seam and pinsink mark and to increase mold cost with shorter die life.
2. When designing injection molding products, if no special requirements, core-pulling should be avoided to the greatest extent, for example, the direction of axial hole and rib should be changed to the mold opening direction by using the kiss-off of cavity and core.
* Integral hinge
1. By using the toughness of PP plastic, the hinge can be designed to be united with the product.
2. Film of hinge ＜ 0.5mm, and it should be homogeneous.
3. The gate can only be designed on one side when doing injection molding of the integral hinge.
* Insert
1. Inlay insert in injection products can increase the local strength, hardness, dimensional accuracy and can set small thread hole (axis), meeting all kinds of special needs; meanwhile, it also increases production costs.
2. Insert is usually of copper; it can also be of other metal or plastic.
3. The parts of insert embedded in plastic should be designed into the structure of rotation stopping and extraction prevention like knurling, aperture, bending and shaft shoulder.
4. The surrounding plastics of insert should be properly thickened to prevent stress cracking of plastic parts.
5. When designing insert, the positioning method（aperture,pin and magnetism）in mold should be fully considered .
The article comes from China injection mold manufacturer - Mold Best Assurance Company Limited, website is www.mbamoldanddesign.com
