As part of an ongoing worldwide evolution in under-the-hood technology, the combination of advanced blow molding techniques, enhanced polymer formulations and creative conceptual solutions developed at DuPont’s Technical Centers are now allowing smarter and more complex parts to be blow molded using high performance engineering polymers.
Major benefits include reduced part inventories through efficient part integration, design for assembly, weight reduction and material recyclability. Improvements in noise, vibration and harshness (NVH) are also possible through material selection and part design, resulting in significant cost savings for systems suppliers and OEMs alike.
The advantages of blow molding for large parts made of commodity or nonengineering plastics have been appreciated by the automotive industry (and by other industries such as packaging) for several years. Advanced blow molding has now become a high-tech procedure. New technologies include parison manipulation, suction blow molding and innovative extrusion techniques. Parison manipulation and suction blow molding have been developed in order to produce scrapless parts (i.e. no pinch weld on the finished part itself) which has led to this procedure being termed 3D blow molding. With the negative effects of the pinch weld eliminated, mechanical performance in critical stressed areas is improved. (Pinch weld effects can be compared with weld line effects in injection molding).
Today, extrusion techniques allow both axial and radial wall thickness control so that these parts have more homogeneous walls. In addition, extrusion techniques now involve sequential extrusion, coextrusion or, frequently, a combination of both. The goal is to use two or more materials for each component in order to create so-called hard/soft material combinations. For example, soft material segments can be used in air duct bellows to replace rubber and give the parts better bending characteristics, or to combine both coupling and sealing functions. The hard material segments will give the component some stiffness and thus improve NVH performance.
Partnership with DuPont results in new concepts
To strengthen their technical offering and defend their competitive position, many companies are developing new part designs and concepts to fully leverage today’s advanced blow molding technology. This requires a partner who can help them explore non-generic material replacement and achieve part and design integration, supporting them at every stage of the project’s development from initial design studies and CAD analyses through prototyping to feasibility tests with finished parts.
If you want to explore how we might work together to speed the development of your new idea or existing project, and for materials and manufacturing options that will shape your concepts and bring them to life — please contact us.