SHAPING A THERMOPLASTIC OBJECT IN THE DESIRED FORM WITHOUT COSTLY MECHANICAL PROCESSING

In the field of RPT (rapid prototyping technologies), one of most limi ting constraints is the restricted choice of possible materials. The s tate of the art is such that material choice is heavily dependent on p rocess type, so that, except in a very few cases, the realized prototy pes can only give, to the end-user, information about shape and design , or represent no more than a single step in a rapid prototyping proce ss (as in the case of models in polycarbonate, produced with SLS techn iques for quick casting). The problem is more acute for injection of p lastic materials, because of the large number of available raw materia ls. In such cases, the only way to obtain a functional prototype, i.e. one produced both with the chosen material and injection method, cons ists of the realization of a test mold. Note that even though techniqu es such as high speed milling do indeed reduce the time-to-market, the y however, weigh heavily on the budget. This project demonstrates that it is possible, for the case of thermoplastic products, to eliminate the intrinsic Limitations that derive from the restricted choice of av ailable materials for rapid prototyping. A process has been implemente d which allows injection of different thermoplastic materials into a m old, realized with ceramic powder not yet sinterized. Practical result s show that it is possible to shape a thermoplastic object in the desi red form without costly mechanical processing. (C) 1998 Published by E lsevier Science S.A. All rights reserved.