Problems of polymer melt in metal powder injection molding

In the process of metal powder injection molding, due to the lack of knowledge, the processing will affect its performance, in general, the basic characteristics are often ignored, at the same time, simply making a template through a component is a fault, so what will happen in the metal powder injection molding polymer melt problem? The following macro new material small make up will give you an introduction to the metal powder injection molding polymer melt will appear in the problem.

Daihong new materials found a lot of metal powder injection molding manufacturers introduce particle molding often seems to be unnecessary prior to drying, but the excess moisture will produce steam, melting will lead to voids and other conditions. Some polymer melt water under the action of molding, hydrolysis degradation occurs more serious, leading to brittle molding, so MIM technical experts suggest that hydrolysis sensitive polymer dry materials should adhere to the use of desiccant or vacuum dryer.

The thermal degradation of the polymer melt rate increase, will cause excessive heat, which in turn will lead to brittle molding, sizing can be within the cylinder for a long time, consumption of polymer stabilizers, due to the requirement of high pressure, the modelling of metal powder injection molding of polymer degradation appear difficult to fill, will fall into temperature common pitfalls, lower the viscosity of the melt, forming more slowly.

As a result, MIM industry leaders have concluded that when polymers degrade, they seem to fill more easily, the viscosity of the polymer melt shearing requires more reaction temperature than it does, and a faster filling rate is more effective for the filling chamber.

Generally speaking, rapid cooling of polymer melt in metal powder injection molding can shorten cycle time and improve productivity. It is also a simple way to achieve precision and complex parts (such as MIM auto parts, powder metallurgy micro gear, powder metallurgy small module gear) of precise size, at least for a period of time after stripping, thermoplastics will not be washed, cooling at a fixed speed. A non-uniform cooling rate leads to shrinkage, resulting in inaccurate dimensions or high residual stresses. If the mold temperature is low, the gate with a small gate size will quickly allow the melt to separate and contract freely in the mold cavity. If so, the molding cycle has long been under high pressure.

The above is the problem of polymer melt in metal powder injection molding. We hope that we can help you with the introduction of these tips. If you have any other questions, welcome to consult our new material technical team!