1. Insert
Inserts into injection products can increase local strength, hardness, dimensional precision and set small threaded holes (shafts) to meet various special needs. It also increases the cost of the product.

Inserts are generally copper, but can also be other metals or plastic parts.

The parts of the insert in the embedded plastic shall be designed with stop-turn and stop-pull structures. Such as: knurling, hole, bending, flattening, shaft shoulder, etc.

2. Reasonably consider the contradiction between process and product performance
The contradiction between appearance, performance and process must be taken into account when designing injection molding products. Sometimes part of the process can be sacrificed, can get a good appearance or performance.

Structural design is unable to avoid injection defects, as far as possible to allow defects to occur in the hidden parts of the product.

3. Precision of injection parts
Due to molding shrinkage when nonuniformity and uncertainty, metal parts, injection molded parts accuracy is significantly lower than cannot simply to use the size tolerance of mechanical parts should select the appropriate tolerance according to the standard requirements. The designer can according to the raw material of the plastic and use requirements, according to the terms of the standard parts of size tolerance. At the same time, according to the comprehensive strength of the factory, the design precision of the peer products to determine the appropriate design tolerance precision.

4. Deformation of injection parts
Improve the rigidity of injection molding product structure, reduce deformation. Try to avoid flat structure, reasonable setting flanges, concave-convex structure. Set proper reinforcement.

5. Buckle
The buckle device is designed to be Shared by multiple buckles at the same time, so that the overall device will not be damaged by individual buckles and cannot operate, thus increasing its service life, and then more consideration is given to add rounded corners, increase the strength. ​

It is the tolerance requirements of the relevant sizes of buckle are very strict, too much inverted buckle position is easy to cause buckle damage; On the contrary, if the reverse position is too little, the assembly position is difficult to control or the assembly part is too loose. The solution is to reserve to change the mold easy to add glue to achieve.