Development of Waste Rubber as a Binder Component for Metal Injection Moulding Process

One of the keys to successful production of MIM is the selection of the binders. The binder-system provides the metal powder with the fluidity necessary for moulding. It also strongly influences the maximum solid fraction of the mixture that can be moulded, the green strength of the moulded part and, the properties of the final products after the debinding process. There are various binder-systems that have been developed for use in practice of the MIM. To overcome at least some of the problems associated with the other systems, a eco-friendly biopolymer composite binder based on natural sources and waste materials had been successfully developed at the Structural Materials Programme of SIRIM Berhad. This consists of natural sources based biopolymer constituents, particularly palm stearin and waste rubber as a back bone polymer. The new system has been successfully used for metal powders to produce precision metal component. The physical and mechanical properties of the sintered samples will be discussed. The highest sintered density achieved was 99.8% of theoretical density with the tensile strength of 517 MPa.