At Johnson Controls, compression molding replacing injection on A-pillar trim


The IAA automotive show in Frankfurt, Germany is the world's largest in the industry, and Johnson Control's stand there always is a major attraction. The stand this year is peppered with interesting plastics applications, as always, but the way some are being made is changing.

Also catching PlasticsToday's eye was a display of the trim from two A-pillars, with one injection molded and the other one compression molded. It is the latter that the company is trending towards, according to two JC employees who spoke with us at their stand. Reasons they gave include lower tooling costs, and the ability to more easily mold a family of these trims in a single mold. For compression molding of these, the thermoformed fabric or other top layer is placed in the tool, with a softened sheet of plastic then robotically positioned on top of the fabric. The parts also leave the mold as a finished product with no need to be concerned about edge trim, as often is the case with back-injection molded A-pillar trim, they told us.

Weight savings also play a major factor in the transition. No acoustic pad is needed, though an inner cartridge must be adhered to the compression molded trim support; this cartridge makes for easier mounting.