The construction of most automotive interior headliners requires an adhesive material to bond polyurethane foam-backed fabric to a molded headliner shell. More than ten years ago, The Dow Chemical Company qualified and began supplying a thermoplastic adhesive polymer film for headliner applications which replaced wet adhesive systems at several fabricators. DAF 899 adhesive film has gained acceptance in the industry due to excellent performance, convenience, and cost effectiveness without additional waste handling or volatile organic emission concerns.
Recent advancements in headliner design such as additional recessed areas with more demanding contours, new substrate materials and the desire for more efficient operations created an opportunity to design improved adhesive films to meet the emerging industry demands. A development program was initiated to determine the key film properties to maximize adhesion at reduced molding cycles with deep contoured parts while maintaining the desired performance properties at elevated temperatures. The research program resulted in the development of a multilayer, multicomponent thermoplastic adhesive film which exhibited excellent deep draw characteristics and significantly reduced molding cycle times. Both adhesive films may be pre-applied to foam-backed fabric to further improve fabrication efficiency.
The paper will discuss the design procedures used to develop a new adhesive film system, headliner adhesive requirements, and review pertinent results from fabrication trials. Adhesive film performance on various headliner substrates and processes and recommended process parameters will also be reviewed.