Plastics have gained a significant place in today's automotive industry. There is a variety of multi-layer tube & pipe constructions, from vehicle fuel and vapor return tubes to larger distribution pipes for filling stations. Manufacturers turn to Multi-Layer Tube (MLT) co-extrusion technology as a solution to their production needs. The increased use of fuel additives like ethanol, stricter environmental regulations, and new raw materials with demanding processing characteristics are the principal drivers when specifying manufacturing solutions.
Fuel and vapor return tube constructions fulfill a variety of requirements. A thick outer layer is needed to protect against ambient conditions and damaging impacts. Additional functional layers serve to meet requirements such as reduced hydrocarbon emissions, properly handled electrostatic charges and increased corrosion resistance. Adhesives are often used in bonding functional layers together in regards to their different rheological properties.
Extrusion groups are available with a rapid layer positioning feature for dozens, even hundreds of possible combinations. Redesigned six- and five-layer extrusion heads have recently been released. The head has a wider processing window thanks to improved distribution and flow channels. Higher viscosity polymers and a larger variety of multi-layer constructions are possible. Plus, the time needed for cleaning and set-up operations is significantly reduced.
The PAL extrusion systems are designed and optimized for manufacturing the most common MLT constructions. Up to six layers are extrudable in one shot. Nitrited barrels and screws, or optional bimetallic barrels and Inconel screws offer the level corrosion resistance imposed by the materials employed. The downstream equipment for a PAL line includes the Nomos precision controls coupled with OEM measurement devices, followed by calibration, cooling troughs, and cutting and/or a fully automatic coiler. Special configurations are available according to customer requirements.
Maillefer's PAL lines offer the high precision, versatility and rigorous quality techniques required by the automotive industry.
Philippe Giovangrandi
Technical Sales Director, Pipe & Tube Business
philippe.giovangrandi@maillefer.net