There are many kinds of degreasing processes. Today, we introduce one of them, Catamold.

Catamold method is a one-step degreasing method developed by Bloemacher of BSAF Company in Germany in the early 1990s. It is a catalytic degreasing method.

The main technical feature of this method is to use polyformaldehyde resin as binder and catalytic degreasing in acid atmosphere. Using long chain polyformaldehyde resin as binder and using polarity of polyformaldehyde resin to connect metal powders. It can be suitable for a wide range of powders. Polyformaldehyde resin is decomposed into formaldehyde catalyzed by acidic atmosphere. This decomposition reaction occurs rapidly above 110 C. It is a direct gas-solid transformation, which is conducive to controlling the deformation of green billet and ensuring the dimensional accuracy after sintering.

Catalytic degreasing happens at the interface between atmosphere and binder. There is no gas in the forming blank. The advancing speed of the reaction interface can reach 1-4 mm/h. CREMER Germany has designed a continuous degreasing and system for Catamold degreasing process. The process of operation is to place MIM forming in the first heating zone of degreasing and heat it to 86 C in nitrogen atmosphere to avoid condensation of nitric acid on the billet in subsequent catalytic degreasing process. Then the forming blank was moved into the catalytic degreasing zone, and the polyformaldehyde resin was decomposed into formaldehyde. After preliminary degreasing, the billet enters the sintering furnace through the first cleaning chamber, and the residual binder is removed in the first heating zone of the sintering furnace. Subsequently, sintering is carried out under the action of nitrogen, hydrogen, argon, decomposition of ammonia and other mixtures. An important feature of Catamold method is that catalyst degreasing can avoid liquid phase when degreasing, which avoids the weakness of MIM products that are prone to deformation and difficult to control size accuracy. It is a major breakthrough in MIM industry. Because of catalytic degreasing, degreasing time is greatly shortened and cost is reduced. The application of metamold method can produce large size MIM parts.

The continuous degreasing and sintering system of CREMER can realize continuous production, making MIM a competitive near net forming technology for PM.

Metamold method is the most advanced MIM degreasing method applied in industrial production. However, it has some problems, such as the acid atmosphere corrode the equipment, waste gas treatment, and the cost of equipment investment is higher than other methods.