Binders that used in the mixing process in stainless steel feeding production as well as the selection and importance of powders


Metal feeding production can be regarded as an indispensable part in metal injection molding industry, as this kind of technology will use injection raw materials that have certain size and even particles instead of directly using powders. Therefore, feeding production is very necessary for the whole metal injection molding industry. Currently, most of the feedings are provided by professional suppliers. Besides, some large technology-using enterprises that have strong economic capability also actively carry out explorations in feeding production field so as to reduce the production cost and produce more feedings that can be suitable for their own production needs.

metal powders for injection moldingWhen we mention feeding production, the mixing process cannot be ignored. Mixing is the first step of feeding production, in which the metal powder surface will be coated with a layer of binder, thus the metal powders can be evenly mixed with binders. Many people know that mixing process is very important in the feeding production, but not all of them will systematically know what kinds of factors will influence the mixing effects. Below, we will introduce some factors that provided by from the angel of the matching of powder and binder as well as the charging order in the following points.

Why should we pay attention to the matching between metal powder and binder? This is because the feeding performances will not be reflected in mixing process; however, they will indirectly influence the injection effects and final products performance in the subsequent injection molding process. Therefore, in the mixing process, the difficulty level of injection molding as well as the deformation degree after debonding should be both considered.

First of all, we should confirm the best matching proportion between metal powders and binders. When the binder proportion is too high, the viscosity of feeding will be reduced, thus it will weaken the contact between metal powder particles and will cause serious deformation or collapsing in the subsequent removal of binder; when the binder proportion is too low, although the viscosity of feeding is improved, it will be easy to form interspace and will be difficult to inject, besides, products will be easy to crack after debonding.

As different kinds of binders will be used in different metal powders in the mixing process, the matching will also vary a lot. Generally speaking, matching should be made according to the mass ratio between metal powders and binder. Some people even have tried to add surfactant in the feeding production, which has been proved by the experiment that it will reduce the wettability of binder on powders, shorten the binder dosage and improve the loading capacity of metal powders in metal feedings.

There are also some strict stipulations about the charging order of powder and binder in the mixing process. Usually, high-melting components will be added firstly for melting; afterwards, low-melting components will be added when the temperature is reduced; finally, metal powders will be added in batches. This will prevent the gasification or decomposition of low-melting components, besides, by adding metal powders in batches, it will prevent sharply increasing of torque caused by fast cooling and also can reduce equipment loss.

In conclusion, mixing process can be regarded as an important process in feeding production. Besides, the matching between metal powders and binders as well as the charging order will have important effect on the mixing process. Therefore, it is very important for feeding production to make matching and charge scientifically.