Hot Products 5-4-98

May 4, 1998 Design News

Hot Products

Materials Editor Gary Chamberlain cites noteworthy plastics products

Nylons break medical barriers

Foster Corp. has achieved what it claims to be a substantial breakthrough with its new line of Fostalon^TM 5000 series flexible nylon compounds. The materials are said to fill a void in the flexural modulus data between 80,000 and 120,000 psi, while insuring dimensional stability with minimal shrinkage after extrusion. Such properties make the materials a good fit for such medical applications as catheters, hubs, and shafts. They are fully compatible with radio-paque fillers, like barium, bismuth, and tungsten. And they are reinforecable with glass beads or fibers when used for hubs and other molded devices.

Compostable plastic commercialized

"Our new polymer demonstrates Eastman Chemical's public commitment to protect the environment," says Joost Berting, project launch manager, biodegradable products. The compostable plastic--EASTAR BIO--combines strength and moisture resistance with "completely safe biodegradability." It can be blended with materials from renewable resources (starch, wood flour) without additives, or used as a paperboard coating. Properties are similar to low-density polyethylene, with processing possible on conventional thermoplastic equipment.

Metallocenes meet FDA requirements

Six grades of Exxon Chemical Co.'s metallocene-based propylene homo-polymers, trade named Achiever, are now FDA-compliant, without restrictions, for food-contact applications. Two of the new grades, 1605 and EXPP-68, are said to provide higher heat-distortion temperature and flexural modulus and lower extractable content than conventional homo-polymer polypropylene. Grades 3825, 3844, 3854, and 3904 are suited for nonwoven and multifilament fine denier fiber and spunbond applications.

Athletes have a ball with thermoplastics

Air bladders used in balls, helmets, footwear, and other sports equipment need to be tough and durable, and they must maintain their integrity despite being repeatedly kicked, hit, compressed, and flexed. In addition, such equipment must withstand environmental punishment, including temperature extremes and moisture. JPS Elastomerics Corp. feels it has such a material in Stevens Urethane. The thermoplastic urethane (TPU) gives these bladders the necessary tensile and burst strength, along with the elasticity and flexibility to "roll with the punches," says JPS' Sam Everett. Slim and sheet products come in thicknesses from 0.001- to 0.125-inch and widths up to 80 inches. Durometers range from 75 to 95 Shore A, with standard or custom colors and surface textures available.

Technology illuminates back-lit parts

A new formulation technology from M.A. Hanna Color combines laser marking with a super phosphorescence additive science. The proprietary system will enable automakers to design low-cost alternatives to back-lit or illuminated control and instrument panels. In addition, say company researchers, the system allows easy marking for components that traditionally have been difficult to illuminate. Hanna FX Nite Brite requires a minimum ambient light exposure to obtain 10 hrs of high-quality illumination. With the addition of a custom colorant into the base resin of a plastic component, the finished molded part can be laser marked with FastMARK^TM laser marking.

Polyethylene resists high impacts

Ticona (formerly Hoechst Technical Polymers) has introduced a thermoplastic polyester that molds easily into highly impact-resistant structural parts for automobiles and appliances. The polyethylene terephthalate, called Impetr Hi 430 PET, contains only 15% glass. At -20C, it exhibits a 40% higher notched impact strength than conventional glass-reinforced PET resins, says program director Steve Leyer. The material injection-molds easily with relatively low tool and machine wear. A variant of the PET grade was used for the body of the Chrysler Composite Concept Vehicle, said to be the largest component ever molded in an engineering thermoplastic.

Nylon 46 increases mold tool life

Electrical and electronic components increasingly need high-temperature plastics that can run at higher processing temperatures requiring special corrosion-resistant steels to mold them. DSM Engineering Plastics has introduced such a material in its "Stanyl New Technology" grades of 46 nylon. The glass-reinforced, V-0 resins are said to substantially prolong screw, barrel, and tool life. And, according to company chemists, show a reduction in corrosion by a factor of 2 to 8 compared to some polyphenylene sulfide (PPS) and polyphthalamide (PPA) grades. Potential uses include: connectors, wire-wound components, electric-motor parts, switches, circuit-breaker parts, and housings.

UV silicones cure fast and tack-free

Loctite has introduced an ultraviolet (UV) light cure silicone technology for electronic, automotive, medical, avionics, military, appliance, and other applications. The product line includes seven products with such performance capabilities as USP Class VI certification for medical devices. The silicones cure tack-free in less than one minute when exposed to a UV light source. They have a thermal resistance to 400F. In contrast, room-temperature vulcanizing (RTV) silicones require one hour to achieve handling strength, and up to 72 hours to cure completely.

Cure validates product applications

Adac Technologies has introduced Cure Zone SC, a bench-top system designed for process applications requiring the curing of tubular and spherical components. The process adapts to lab or production use. It generates UV/visible light to cure photochemically initiated formulated coatings, encapsulants, and sealants that absorb energy in the 250- to 600-nm range. The system automatically cures a 360-degree-circumference of components up to 1.75 inch in diameter and has a cure length of four inches.