DuPont Engineering Polymers is launching a series of new products at NPE aimed at enhancing aesthetics and offering process and productivity improvements.
The materials include a thermoformable acetal; platable, paintable acetals; a paintable, super-gloss thermoplastic polyester for automotive body panels; and platable grades of nylon. The Wilmington, Del.-based unit of DuPont Co. also unveiled a semi-permeable membrane for hydrating plants, two flame-retardant nylon grades for electrical uses, a processing aid, and some new, encouraging test results related to a pilot project for recycling large, glass-filled nylon auto parts.
Prior to NPE, DuPont surveyed nearly 300 molders and original-equipment-manufacturer designers and engineers who planned to attend the trade show. Respondents ranked thermoforming (14 percent) as second only to injection molding (34 percent) as ``the most important process technology in the next five years.''
William Hsu, vice president of technology, cited the finding June 24 as he introduced a new, thermoformable acetal resin, labeled Delrin forming solutions, at a news conference at DuPont's booth (S2655). The development allows users to thermoform and decorate housings, panels and other products out of acetal, which DuPont says offers better chemical resistance and lubricity than competitive materials such as polycarbonate or ABS. Such parts can be painted, printed, in-mold coated, foil stamped, or decorated by other means.
DuPont said Penn Fibre Plastics Inc. of Bensalem, Pa., is supplying thermoformable Delrin sheet, and identified thermoformer Freetech Plastics Inc. in Fremont, Calif., as an early developer of commercial parts using the material.
Hsu also introduced Delrin decorating solution, a complete system that includes acetal resin, an etching solution, and three compatible coatings and paints. He said product designers now can give parts molded from Delrin an ``unplastic'' look of painted or shiny, metal-plated components. The etching solution, called Delrin Etch, activates the part's surface to accept the appropriate DuPont coating. The firm suggests various possible applications, including ski bindings and boot buckles, automotive speaker and vent grilles, plumbing fixtures and cosmetic packaging.
The company also introduced Shine-E Rynite, a high-heat, thermoplastic polyester targeted for use as painted automotive body panels and unpainted appliance parts. Dave Ritchey, Rynite global business manager, said body panels molded from the material can be painted right next to metal body panels on an automaker's paint line, including 428° F ovens, and yield a Class A finish. The polyester offers not only superhigh-gloss, high-temperature resistance and toughness, but also excellent dimensional stability since it has very low moisture absorption, Ritchey said. The finish right out of the mold is said to be good enough to be used unpainted in such appliance applications as oven handles.
Another aesthetic advance involves the launch of two platable grades of Zytel HTN nylon designed to offer a cost-competitive alternative to plated metal in situations where ABS and some other platable plastics lack adequate temperature resistance, stiffness or chemical resistance.
Terry Caloghiris, Engineering Polymers vice president and general manager, called attention to DuPont's new Apexa hydration system that it says could help make unusable farmland around the world more productive by allowing the use of brackish water for crop irrigation. The system's key element is a proprietary, semipermeable membrane that allows cleaner water vapor to pass through the soil, while retaining most undesirable salts. The double-walled structure features ribs that form internal channels to hold water. The monolithic membrane has no holes to clog.
DuPont also introduced two flame-retardant grades of Zytel glass-reinforced nylon resins designed to replace thermosets such as electrical-grade bulk molding compounds in circuit breaker housings, switch-gear, fluorescent lighting and other applications. The firm claims benefits of faster molding cycles, thinner walls to reduce part size, and the ability to recycle scrap.
The firm also has developed a new grade of unreinforced nylon 6/6 resin that can act as a productivity aid by cutting cycle time when molding difficult or oddly shaped parts. The material, Zytel FE310014, is supplied as a pelletized concentrate.
Finally, DuPont revealed test results from a composites recycling program that it has been conducting with Japanese auto parts supplier Denso Corp. Driven by the European Union's mandates for closed-loop, end-of-life vehicle recycling, the project involves reclaiming large, glass-filled nylon auto parts - in this case radiator end tanks - at a prototype recycling plant in Canada.
Hsu said DuPont's Composite Recycle Technology process ``can provide a workable, cradle-to-cradle solution for radiator end tanks.'' He said the process also should be able to handle air-intake manifolds and other glass- and mineral-filled thermoplastic parts.
