Powder Injection Molding
“Through a combination of plastic, wax and metal or ceramic powder a material is generated which can be processed by injection moulding. This material is generally named - feedstock - . By custom machine and tool technology, this feedstock can be injected, similar to plastic injection molding. The moulded part is so-called green part. The next step is the release of the plastic and wax component by the debindering process. The result is called brown part. The last step is the sintering of the brown part. In this process the individual particles are merged together, the brown part shrinks and becomes an compact component. This sintering shrink depends on the proportion of powder in the feedstock: normally between 20% and 30%. This final component has similar properties to the base material.”
Recent Journal Articles
Optimization of powder injection molding of feedstock based on aluminum oxide and multicomponent water-soluble polymer binder
(1376–1382) Polymer Engineering & Science 51 #7 (2011)
Hausnerova et al of omas Bata University in Zlín and the Academy of Sciences of the Czech Republic, measured the thermal and pressure-volume-temperature characteristics. Upon shear deformation the feedstock undergoes structural changes, which are quantified in terms of yield stresses obtained using Herschel-Bulkley and Casson methods. Further, the rheological model is developed to describe the flow behavior of the feedstock in the whole shear rate range measured. (RDC 6/24/2011)