A new liquid crystalline polymer based processing aid and its effects on micro-molding process

There are increasing demands in recent years in manufacturing of polymer micro-components due to the worldwide trend slanting towards miniaturization. However, polymer materials specially tailored for micro-molding applications are yet to be developed. In the micro-molding industry selected commercial materials developed for the conventional molding applications have been used in micro-molding applications. There are limitations for many of these materials to be used successfully in practical applications because there are stringent requirements on both the material flowability and mechanical properties. The ease with which the part accuracy can be achieved is the decisive criterion for material selection in micro-molding process. To achieve desired part accuracy, materials with low melt viscosity are desirable. For many engineering plastics, the low flowability is the main drawback for their wide applications in the micro-molding process. In the present work, a new liquid crystalline polymer (LCP) based processing aid has been used to assist in micro-molding of a polycarbonate resin. It has been found that the viscosity of the PC resin can be greatly reduced by adding a small amount (2 wt.%) of the processing aid. And the filling behavior of the blend has been greatly improved in the micro-molding process compared with the original resin.