TPV eliminates processing and appearance issues

When the interiors of Ford Motor Co.’s full-size SUVs were refreshed for the 2003 model year, designers intended to use a thermoplastic vulcanizate (TPV) elastomer to achieve resilient, soft-touch console liners and cup holder inserts. However, the decision created significant processing issues.

Tools designed for a conventional TPV material were experiencing air entrapment, and some of the more complex console liners were very difficult to remove from the mold cores, resulting in longer cycle times.

Solvay Engineered Polymers approached the problems from two directions. Materials personnel recommended changing the material to Solvay’s Respond TPV. At the same time, engineers in the CAE department addressed part and mold design.

CAE simulations showed that for four of the six liners and inserts the change of material to Respond SX70 would practically eliminate both mold-fill and part-release issues. The flow of this material is better than that of the initially specified TPV.

For the two most complex console liners, the design of both the parts and the tooling had to be changed. Working with engineers from the molder — Visteon Carplastic in Mexico — Solvay recommended changes in the design of the part: lowering the height of the ribs, redirecting the orientation of the slots and altering the thickness of the divider walls. With changes to the location of the gating of the tool, material flow was redirected through the part, eliminating air entrapment. Finally, an air-ejection system was designed for each tool to assist in release of the parts from the mold.

Solvay Engineered Polymers 905-738-6433