DuPont (Booth S3342) is packing a number of new material grades in its NPE suitcase, including advancements in nylon, acetal and liquid crystal polymers. "We're offering system solutions," said William Hsu, vice president of technology for DuPont's engineering polymers unit. "The bottom line is we ought to be able to help our customers make their products better."
This strategy has led DuPont, the Wilmington, Del.-based chemicals giant that ranks as one of the world's largest engineering resin makers, to develop metal-replacement grades of its Zytel HTN-brand nylon and more flame-retardant grades of its Zytel-brand nylon.
The Zytel HTN products are aimed at replacing metal in automotive structural parts. Primary applications here include chassis parts, struts and several interior and exterior uses, according to Carl Sullivan, product manager for DuPont's Zytel HTN and Zenite liquid crystal polymers.
"In structural components, a material has to be stiff and tough at the same time," Sullivan said. "These qualities are usually opposites, but we've been able to achieve them with loadings of up to 50 percent glass.
Although some structural parts on cars already have switched from metal to plastic — particularly in Europe — most similar parts on trucks are still metal, creating a significant business opportunity.
Nonautomotive applications for the new Zytel HTNs include water-heating systems and appliances.
DuPont's flame-retardant Zytel nylons have been improved to shorten molding cycle times by 20-30 percent and to allow circuit breakers and other electronic parts to withstand temperatures of as much as 104§ F higher than previous flame-retardant Zytels.
"The flame-retardant additives are at similar levels, but the difference with the new grades is in being able to get better flow without sacrificing strength," Zytel nylon specialties manager Ross Petermann said.
The new flame-retardant Zytels also could find a home in electrical connectors, since they now can be molded with smaller pin spacings than previous grades.
In acetal, DuPont's Delrin-brand resins have been enhanced to provide longer life cycles for gears in motors for automotive parts and office machines, including printers.
"Automotive electric motors for window lifts and windshield wipers are getting smaller and running hotter," Delrin product specialist Kathy Schodt said.
"Some of them now have to withstand temperatures of up to [176° F]."
But automotive motors can be externally greased, unlike office machines, where greasing would interfere with printing. To get around this issue, DuPont has added an advanced lubricant system to one of its new acetal grades.
The lubricant system also has allowed DuPont to reduce squeaking and other noise in gears for printers and other office machines.
Advances in DuPont's Zenite liquid crystal polymers have allowed the material to challenge polyphenylene sulfide in a number of electrical connectors used in computers, Sullivan said. The new Zenites can be substituted for PPS with no tooling changes, he added.
"PPS can be brittle and produce too much flash in small parts," Sullivan said. "When you go into a plant and see three people standing around trimming flash from parts, you know there's a problem to be solved."
Other new LCP grades from DuPont offer low warpage, allowing the materials to be more freely used in electronic parts used in circuit boards. Parts made with the low-warp LCPs can expand along with the circuit board as temperatures rise and still not warp.
Zenite LCP also is being developed for use as a layer in HDPE fuel tanks, where its low permeation and high chemical resistance would allow fuel tanks to meet California's stringent low permeation requirements for motor vehicles.
DuPont also will debut conductive grades of nylon and acetal that can meet shielding requirements in cellular phones and static-dissipation requirements in automotive fuel-system parts, including fuel caps, filler necks and fuel-line clips.
"Anyplace fuel flows, static can build up," Petermann said. "If it builds up to high-enough voltage, it can cause a leak in a metal part or even ignite."
These static-dissipative qualities also could be useful in conveyor lines used in manufacturing or in printers and other office machines, he added.
Two other new products — the ELCee injection molding screw and CAMdo computer-aided molding software — are moving DuPont into nonresin areas of the industry.
Both products were developed by DuPont researchers and are designed specifically for use with DuPont resins. The ELCee screw can shorten molding cycles and reduce part rejects, while the CAMdo software can increase molding productivity by offering help in mold design, process analysis and other areas, officials said.
The ELCee screw is being produced and marketed for DuPont by Spirex Corp. of Youngstown, Ohio. Axe Communication Enterprise of Geneva, Switzerland, is handling production and marketing of CAMdo software.
Plastics — including nylon and polyester resins and film — accounted for about $13 billion, or roughly 48 percent of DuPont's total 1999 sales of $26.9 billion.
