What are the factors affecting the shrinkage rate of metal powder injection molding?

1、 Resin pressure: has a significant impact on the shrinkage rate of metal powder injection molding. If the resin pressure is high, the shrinkage rate is low, while the size of MIM material products is large. The metal powder injection molding manufacturer found that even in the same the first mock examination cavity, the resin pressure varies with the product shape, so the shrinkage is also different. In the case of multi cavity molds, the resin pressure inside each cavity is prone to differences, resulting in different shrinkage rates of each cavity.

2.、 Mold temperature: Whether it is amorphous resin or crystalline resin, if the mold temperature is high, the shrinkage rate will increase. Dahong New Materials maintains the mold temperature at a specific temperature during precision molding. MIM technology experts remind everyone to pay attention to the design of the cooling circuit in mold design.

3、 Gate cross-sectional area: Generally speaking, when the gate cross-sectional area changes, the shrinkage rate also changes accordingly. The shrinkage rate decreases with the increase of gate size, which is related to the fluidity of the resin.

4、 Product wall thickness: The product wall thickness also affects the yield rate. Dahong New Materials found in metal powder injection molding that for amorphous resins, the influence of resin on wall thickness shrinkage tends to be different. The larger the wall thickness, the greater the shrinkage rate, and vice versa. For crystalline resins, it is especially important to avoid significant changes in wall thickness. In the case of multiple cavity modes, if the thickness of the cavity wall is different, the shrinkage rate will also be different.

5、 When using glass fiber reinforced resin, the more glass fibers there are, the smaller the shrinkage rate. The flow direction shrinkage rate of metal powder injection molding is smaller than the horizontal shrinkage rate. Dahong New Materials has significant differences according to the different resins. To prevent deformation and warping, we remind everyone to consider the shape, position, and number of gates.