Systems engineering: Injection molding debinding

Powder Injection Moulding is a spray cast technique for manufacturing sophisticated components, in particular in the field of ceramic or metal component manufacturing.

The debinding process thus represents a central step in the process chain and can be accomplished either through the use of solvents or water with our system. 


1. Knowledge: powder injection molding

With the PIM (power injection molding) technique metal or ceramic components (MIM: metal injection modling, CIM: ceramic injection molding) are manufactured using spray cast.

The advantage of this technique lies in the possibilty to realise a process for a higher output and/ or technically more sophisticated parts, but simultaneously complying with excellent tolerance.


2. The process of powder injection molding has four stages:

Material preparation

First, ceramic or metal powder is homogenized with organic binder so that the powder particles are coated with the binder. The resulting mass is then referred as "feedstock".


In this phase the feedstock is injected into liquid tempered steel tools. After its solidification the so-called "green parts" are removed from the tool.


In the debinding phase the binders from phase 1 are removed from the green parts. This is accomplished using special solvents (but also water is possible) and the extraction of the solvents using our plants. 


After loading the debinding vessel with the green parts the vessel will be evacuated by a vacuum unit. As soon as the given vacuum level is reached the reactor chamber is flooded with solvent.


During the debinding process the binder is dissolved from the green parts by the heated solvent under constant circulation.


In order to minimize emissions the solvent is cooled during the discharging process. At the end of the debinding phase the solvent is depleted into a integrated buffer tank.


In the following drying process, the components are dried by means of inert gas under vacuum. The resulting solvent emission condensates in a special heat exchanger and are re-introduced to the process.


The contaminated solvent is cleaned in the last process step using vacuum destillation in order to separate the binder (or the water) from it so that the solvent can be reused for a further debinding processes.


After the debinding the porose parts are called "brown parts", which then are condensed in a furnace process ("sintering") and so get their final form and material characteristics.


Medium and large quantities can be handled using two simultaneous operating and communicating plants: a debinding and drying plant as well as a solvent recycling plant.