Details are in on nylon 1212; also new nylon TPE's.

Details Are In on Nylon 1212; Also New Nylon TPE's

Reported here are the first details to be released by Du Pont Co., Wilmington, Del., on its fledgeling nylon 1212 line, the first appearance of this new polyamide type, as well as on four newly commercial nylon-based thermoplastic elastomer alloys, another new family from Du Pont.

At least six grades of crystalline nylon 1212 will be commercialized this year, including reinforced, unreinforced and plasticized versions for injection molding and extrusion, with a major focus on automotive and fluid management applications, according to John Barineau, product manager. He said the new nylon is designed to compete with metal as well as with nylon 11 and 12.

According to Du Pont, nylon 1212 offers incremental advantages over n ylon 11 and 12 in price, high-temperature resistance, low-temperature impact, dimensional stability and retention of stiffness, moisture absorption, and chemical resistance. He indicated the new nylon 1212 will be priced about 5% below nylon 12, which costs around $3.92/lb.

The nylon 1212 line to be commercially introduced this year is expected to include two unfilled grades (CFE3535HL and CFE3536HL); 23% and 33% glass-reinforced grades (CFE5012H and CFE5013H); and two heat-stabilized plasticized grades (CFE3008HL and CFE3011HL). Table 1 shows properties of two examples. These materials, to be produced by Du Pont Canada Inc. at Maitland, Ontario, have been fine tuned through customer trials over the past 18 months. Applications will concentrate on parts for auto fuel and coolant systems brakes, valves and gears.

The unreinforced Zytel CFE3535HL grade has a melt-flow range suitable for thin-wall molding and profile extrusion, according to Du Pont. The entire 1212 nylon line also features a new proprietary mold-release agent designed to improve cycle times, as well as a colorless stabilizer for enhanced resistance to heat and automotive fuels.

NEW NYLON TPE's

Du Pont is also commercializing four unfilled grades of crystalline Zytel FN (flexible nylon) alloyed with acrylic rubber. These new TPE's, formerly designated ETP (see PT, June '88, p. 109; Aug. '88, p. 51), are said to offer a unique balance of flexibility and toughness at extreme temperatures, as well as good chemical and environmental resistance and exceptionally easy processing.

Three grades (Zytel FN 714, 716, and 718) are for injection molding and based on nylon 66; the fourth (Zytel FN 726) is based on nylon 6 and designed for extrusion and blow molding. Donald Grimes, development programs manager, said the four span a hardness range from Shore 50D to 65D, with flexural moduli between 40,000 and 70,000 psi (see Table 2 for one example), densities of 1.02-1.04, tensile strengths of 4000-5600 psi, elongations of 270-300%, and service-temperature range from -40 F to 302 F (with a short-term heat deflection up to 392 F). Processing range is 520-570 F. Resistance to ASTM No. 1 and No. 3 oils is said to be very good. All four neutral-tone grades can be colored with standard concentrates and painted in automotive paint systems.

Priced between $2.15 and $2.28 per pound, the materials have been designed to compete with thermoset rubbers, TPU's and plasticized nylon 11 and 12 in such applications as under-the-hood automotive components, hose and tubing, footware, fasteners, seals and gaskets, and sporting goods such as ski boots.