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New Renault Clio has injection molded hatch

November 9, 2012

BERWYN, PA. (Nov. 9, 11:45 a.m. ET) — Styron LLC has been involved in a two-year development project leading to the launch of a thermoplastic hatch on the new Renault Clio car. The hatch is injection molded in three PP compounds developed by Styron.

The inner skin is injection molded using a talc filled PP compound. This connects to the structural part which is produced with a concentrated long glass fiber-filled PP resin (LGF-PP) developed by Styron. The concentrate is blended at the molding machine with a PP copolymer resin.

The outer skin is made with a blend of a PP impact copolymer grade, a specifically formulated 70 percent talc masterbatch and color concentrate. Styron says this method, which it calls Inspire At-Press, allows for a tailored mechanical performance to meet the specific application requirements.

“The automotive industry has been looking for alternatives to steel for lift-gates [hatches] for many years. Weight savings, styling freedom and function integration are the main objectives,” said Marjolein Groeneweg, marketing manager at Styron Automotive.

Berwyn-based Styron supported Renault in the engineering phase with process simulations to develop a thermoplastic hatch, as the company wanted the hinges and the closing mechanism to be hidden. The company also addressed issues to do with external conditions, such as exposure to high/low temperature in humid environment which can cause deformation.

Styron said LGF-PP was used to help improve impact resistance, expansion and durability of the structural part of the hatch. Using a material with higher glass content improves the stiffness and toughness of the structural part.

The company said that choosing a material composition and manufacturing process that achieves the desired glass fiber length distribution was critical to meeting the specific performance requirements of the Clio's hatch.

In addition, Styron also supported Renault in selecting the appropriate plasticizing screw to maintain the required fiber length and also in optimizing the injection mold design.