Comparison of two setups for induction heating in injection molding

To eliminate defects and improve the quality of molded parts, increasing the mold temperature is one of the applicable solutions. A high mold temperature can increase the path flow of the polymer inside the cavity allowing reduction of the number of injection points, reduction of part thickness, and moulding of smaller and more complex geometries.

The last two aspects are very important in micro injection molding. In this paper, a new embedded induction heating system is proposed and validated and two different coil setups were tested and compared. An experimental investigation was performed based on a test geometry integrating different aspect ratios of small structures.

Acrylonitrile butadiene styrene (ABS) was used as material, and different mold temperatures were tested. The replicated test objects were measured by means of an optical coordinate measuring machine (CMM). On the basis of the experimental investigation, the efficacy of the two induction embedded coils, with respect to improvement of replication quality, has been verified.