MEDPIMOLD Technology

The technology to produce ceramic or metallic parts by Medium Pressure Powder Injection Molding is straightforward and includes the following steps:

Powder pre-processing
Feedstock preparation
Medium pressure injection molding
Binder removal by thermal evaporation or supercritical CO2 extraction
Sintering

… in brief
A high-solid content mixture (feedstock) of ceramic or metal powder and a wax-based binder is melted and injected under pressure into a tempered one- or multi-cavity mold tool. The solidified molded part is then ejected from the tool, and the organic binder is removed thermally in a debinding furnace or, alternatively, by supercritical extraction. The remaining powder body is sintered (fired) in a furnace at high temperature to a dense, high- strength component. Typical linear shrinkage during sintering is 10-15 percent.

An automatic one-cavity mold tool for production of watch cases of stainless steel, zirconia as well as alumina. The production rate with this tool is four to five cases per minute

Four stages during production of watch cases of stainless steel by medium pressure powder injection molding: 1. injection molded 2. cleaned 3. debound and 4. sintered

Powder injection molded watch cases and links of washed stainless steel and aluminium oxide (alumina)

Complex-shaped metal and ceramic parts formed by Medium Pressure Powder Injection Molding – MEDPIMOLD – are used in a number of industrial applications as well as in many consumer products. Our customers have selected it because of the desirable combination of low-cost, flexibility, and shape complexity. Up till now, parts of the following materials have successfully been manufactured:

Metals – MIM

Stainless 316 Steel
High-Speed Steel (HSS)
Low-Alloy Steel
Iron
Tungsten Carbide
Tungsten
Cobalt
Titanium

Ceramics – CIM

Alumina
Zirconia
Silicon Nitride
Silicon Carbide
PZT (Piezo material)
Leucite
Steatite
Glass

With Goceram’s feedstock preparation concept, well-adapted feedstocks with high-solid content are obtained. For instance, the solid content of stainless steel powder (grain size less than 16 micrometers) is 65 volume percent and of fine aluminium oxide powder (mean grain size of 1 micrometer) is 62 volume percent.

A relative comparison of different PIM technologies

	Type of injection	Molding technique	MEDPIMOLD
	High pressure	Low pressure	Medium pressure
Investment cost	high	low	medium
Molding tool cost	high	low	low
Service cost	medium	low	low
Automation capability	good	unknown	good
Prototyping capability	poor	good	good

Equipment and technologies

The GOCERAM production line includes:

Feedstock Mixers for rapid homogenisation of powder and binder
Medium Pressure Injection Molding (MPIM) Machines for cost-effective shaping of complex components using environment-friendly wax-based binder systems
Debinding Furnaces without or with weight loss rate control, documenting the removal of binders and other volatiles from green parts in various atmospheres
Supercritical CO2 Extraction Equipment facilitating high-speed production of thin- and thick-walled parts to very fine tolerances
Specially designed sintering furnaces
Automation equipment

Experienced customers may purchase selected machinery only. For customers completely new to the technology, Goceram will be involved all the way from the first test run to the start up of the production at the client’s manufacturing site.

Please contact us if you want us to carry out a test run of a specific material and component according to your wishes. We will do this as a technical service and share the cost between us. Such a run will help you to decide that MEDPIMOLD is the technique you should choose for the production of complex shaped parts of almost any material.

The trademark MEDPIMOLD® covers all the machinery and technology related to the Medium Pressure Powder Injection Molding technique.