Warping and deformation

                                           Warping and deformation

   Warping and deformation of injection products is a difficult problem.It should be solved mainly from the aspects of mold design, while the adjustment effect of molding condition is very limited.The causes and solutions of warping and deformation can be referred to as follows:

1) when deformation is caused by residual stress caused by forming conditions, stress can be eliminated by reducing injection pressure, increasing mould temperature and even resin temperature, or by annealing.

2) when the stress deformation is caused by bad demodulation, it can be solved by increasing the number or area of push rods and setting the deviation of demodulation, etc.

3) if the cooling method is not suitable, the cooling method can be adjusted and the cooling time can be extended when the cooling is not uniform or the cooling time is insufficient.For example, a cooling loop can be set as close to the deformation as possible.

4) for the deformation caused by molding shrinkage, it is necessary to modify the mold design.The most important thing is to make the wall thickness of the product consistent.Sometimes, as a last resort, the molds have to be repaired in the opposite direction by measuring the deformation of the product.The resin with high shrinkage rate is generally crystallized resin (such AS polyformaldehyde, nylon, polypropylene, polyethylene, PET resin, etc.) with greater deformation than non-crystalline resin (such AS PMMA resin, polyvinyl chloride, polystyrene, ABS resin and AS resin).In addition, because glass fiber reinforced resin has fiber orientation, deformation is also large.