the shrinkage of plastic parts, due to the nature of plastic ( to expand when hot and to shrink when cold), the dimension of plastic parts after molding and cooling is smaller than that of the cavity.
the shrinkage of plastic parts, due to the nature of plastic ( to expand when hot and to shrink when cold), the dimension of plastic parts after molding and cooling is smaller than that of the cavity.
Reduce shrinkage: Extend the cooling time of the injection mold. Reduce the mold temperature. The product wall is thin. The resin melt temperature is lowered during the injection molding process. Greater injection speed. Greater packaging / maintaining pressure and volume. Fillers such as talc, glass beads, or fiberglass (more anisotropic shrinkage with fibers).
In order to change the shrinkage of the material,An easy way is to let your supplier change the recipe;
Another way is to change the mold design to get the size you want; The last method is to optimize process parameters such as molding temperature, melt temperature, injection speed/pressure/time, and cooling time.
Injection speed/pressure/time is the most complex part in the injection molding because these parameters are inter played each other greatly. The key is to design the processing parameter according to the product structure to control the melt filling in the injection mold. Normally, less weight will result in higher shrinkage and higher weight will get low shrinkage. Also, the cooling design is also very important.
Shrinkage is a very important parameter in injection molding
It is not easy to define the exact shrinkage rate
but also it is not easy to control
actually it is very difficult to control shrinkage
your experience is very helpful
I like to read your blog, it is very helpful
every mould engineer will accept your opinion