In-mold decoration creates durable badge for Chevrolet

The famous bowtie emblem of GM's Chevrolet brand has received a makeover with the application of in-mold decoration (IMD) in the 2013 Traverse model to generate a jewel effect. Processor Eimo Technologies (Vicksburg, MI) worked with fluoropolymer-based film supplier Soliant Films (Lancaster, SC) to perfect the process.

In-mold decoration shines through in vehicle badge.

The process involves placement of thermoformed and trimmed IMD film inserts into an injection tool. Eimo worked Soliant to get the top coat of the 0.5-mm-thick film (i.e., the decorative layer that is are similar in thickness to a paint coating) so it would be flexible enough to "mold" to the textured cavity when the injected resin forces the inlay into the cavity of the tool, while ensuring enough durability to withstand the weather and stone impingement. The film itself is based on an alloy of the PVDF fluoropolymer and acrylic resin and boasts good chemical resistance. The casting process for the film also ensures minimized internal stresses.

The new emblems are much more robust; retaining jewel appearance throughout the life of the vehicle. Previously, emblems were made of translucent acrylic and were vacuum metalized. This process generates 6% more scrap than the new process, and the emblems are thicker, weighing 10% more than the new ones. Emblem sizes vary from ~2 x 6 inches (weighing 0.029 lb) to 3 x 9 inches (weighing 0.070 lb).

The use of in-mold decoration (IMD) technology in the automotive sector has increased exponentially over the last few years and it is being used more and more in applications such as instrument panel trim, console/shifter trim, radio bezels, steering wheel trim, door spears, and switch plates in the interior, to exterior panels like window trim, pillars and rocker panels according to Gregg Greider, program manager at Eimo Technologies.

"While badging is just starting to gather momentum [with the Chevrolet exterior badging being perhaps the first example], body side moldings, rocker panels, chin spoilers, and even composite roof panels have all been made using IMD in the USA," he adds.