Analysis of several reasons for the deformation of two-color plastic molds?

Author: MULAN -Plastic Molding Manufacturer

Sometimes we will find that the two-color plastic mold products will be deformed. So do you know the reason why the two-color plastic mold products will be deformed? The following mold manufacturers will introduce to you. There are generally several reasons for the deformation of two-color plastic mold products.

1. Residual stress due to molding conditions; 2. Residual stress generated during demoulding; 3. Deformation due to lack of cooling time. 4. Residue caused by the shape of the product, especially the relationship between the forming shrinkage rate and the thickness of the product stress. Knowledge related to the deformation of two-color plastic mold products 1. The deformation of the product (warping, bending, small wrinkles) is the same as the cause of the crack. That is, the residual internal stress in the product.

The setting conditions for molding should be set in the direction of eliminating the internal stress of the product. That is, after increasing the barrel temperature and mold temperature, the injection pressure should not be too high when the material flow becomes better. 2. In order to reduce the residual internal stress, there is an annealing treatment, that is, the heat distortion temperature is below 10 degrees, and the heating for more than 2 hours can eliminate the internal stress.

However, this method of annealing is not widely used due to its high cost. 3. Assuming that the cooling water holes of the two-color plastic mold cannot uniformly cool the product, residual stress will also occur, which means that the cooling water holes should not be too shallow. If this happens, don’t panic, here we introduce the method of concentrated treatment 1. Immediately: fully cool and solidify in the mold (extend the cooling time timer), increase the temperature of the barrel, and reduce the injection pressure.

2. Short-term: Make the mold cooling uniform. 3. Long-term: To prevent the difference in product thickness, set the gate in the center of the product with large thickness. Because the straight line is easy to cause warping, a large R curve is made, and the mold with reversible bending of the product increases the number of ejector rods and increases the demoulding slope.