Warpage deformation

The main reasons are: uneven curing of the molding compound and shrinkage of the product after demolding.

Generation mechanism and countermeasures: The chemical structure changes during the resin curing reaction, causing volume shrinkage, and the uniform curing makes the product tend to warp toward the first curing side. Secondly, the thermal expansion coefficient of the product is larger than that of the steel mold.

①Reduce the temperature difference between the upper and lower molds and make the temperature distribution as even as possible

②Use cooling fixtures to limit deformation

③Appropriately increase the molding pressure, increase the structural compactness of the product, and reduce the shrinkage rate of the product

④ Prolong the heat preservation time appropriately to eliminate internal stress

⑤Adjust the curing shrinkage rate of SMC material

Blistering: semi-circular bulging on the surface of the cured product

Generation mechanism and countermeasures:

It may be that the material is not completely cured, the local temperature is too high, or the volatile content in the material is large, and the air traps between the sheets, which makes the semicircular bulge on the surface of the product.

① Increase the molding pressure appropriately

②Extend the heat preservation time

③Reduce the mold temperature

④Reduce the unwinding area

The surface color of the product is uneven

Generation mechanism and countermeasures:

① The mold temperature is not uniform, and the part is too high. The mold temperature should be properly controlled

②Poor fluidity of the molding material, resulting in uneven fiber distribution, generally can increase the molding pressure to increase the fluidity of the melt

③Pigment and resin can't be mixed well in the process of color paste blending