Materials.

Many more engineering thermoplastics made their debut at NPE '94 than were revealed before the show. Polycarbonates and PC blends were the most numerous category (see also Technology Newsfocus). There were also several new TP elastomers, some new styrenics, and new conductive grades.

Prominently featured among new polyolefins were PP copolymers, including high-flow and impact grades. Also new were several CPVC compounds and sheet products, and several compounds based on recycled resins.

POLYCARBONATES & PC ALLOYS

Several polycarbonate and PC-based blends were introduced by the Polymers Div. of Miles Inc., Pittsburgh. One was Makrolon T-7435, an opaque, impact-modified PC designed for high flow (17.5 g/10 min) in thin-walled, injection molded telecommunications housings, electronic components, and sporting goods. It's said to have better low-temperature impact strength than most polycarbonates (9.0 ft-lb/in. at -22 F, 13.9 ft-lb/in. at 73 F).

Apec DP 9-9340 R is a new high-heat PC (284 F HDT at 264 psi) from Miles, designed for medical parts requiring steam and autoclave sterilization (up to 100 cycles).

Miles also has several new grades of PC/PET blends. Makroblend DP4 1385 is an opaque medical grade with HDT of 260 F (at 264 psi) and superior resistance to gamma, ethylene oxide, and autoclave sterilization. Makroblend DP4 1380 and 1381 are clear medical grades. DP4 1381 has an HDT of 286 F and superior impact strength, while DP4 1380 is a high-flow version with an HDT of 185 F.

Dow Plastics, Midland, Mich., brought out Calibre 5101-15, a new high-flow (15 MFR), 10% glass-filled PC for thin-walled, injection molded automotive parts.

Calibre 891, another new PC from Dow, features improved ignition resistance, as well as high flow (20 MFR), high impact, and enhanced mold-release properties for injection molded business-equipment housings. It has a UL 94-5V flame rating at 1/8 in., HDT of 264 F at 264 psi (285 F at 66 psi), notched Izod impact of 13 ft-lb/in., and Gardner impact above 640 in.-lb.

Polymer Composites Inc., sub. of Hoechst Celanese Corp. in Winona, Minn., unveiled two Celstran long-fiber reinforced PC/ABS blends (25% and 40% glass) for electronic and computer applications. The two blends offer UL 94V-0 and 5V-A flame ratings, as well as increased stiffness, impact resistance, and dimensional stability for large, complex structural parts.

GE Plastics, Pittsfield, Mass., has a new ABS/PC blend, Cycoloy MC1300, for automotive plating uses. It boasts improved flow and improved plating adhesion, both of which are said to yield fewer rejects.

GE also recently introduced Xenoy 1731, weatherable black PC/PBT for auto exteriors; it does not require painting. Xenoy 1731 is used in cowl vent grilles and mirror housings on GM trucks.

Spartech Compounding, Cape Girardeau, Mo., has two new polycarbonate alloys. One is SCA12-1010, a ABS/PC alloy for the electrical/electronic, computer, and business-machine markets. The other is S7A21-2063 PC/PET for the transportation and lawn-and-garden markets.

MORE ENGINEERING RESINS

A miscellany of other engineering grades were introduced at the show.

* ABS: Cycolac EPBM from GE Plastics, is an automotive plating grade that's said to show improved flow and improved plating adhesion for lower reject rates.

Dow Plastics introduced Magnum 4425 FR-ABS for computers and business machines to "round out" the Magnum 4400 line. This new grade is said to offer higher heat resistance than other grades in the family, plus a combination of the highest uv resistance and practical toughness that is unmatched by the other grades. It has 7.3 MFR (lowest of the group), notched Izod value of 3.5 ft-lb/in., HDT of 164 F at 264 psi, and UL 94V-0 rating at 0.062 in., 94-5VA at 0.100 in.

* Acetal: BASF Corp. Plastic Materials, Parsippany, N.J., has brought out a new high-molecular-weight acetal copolymer containing a proprietary additive for rapid crystallization, faster cycle times, and enhanced mechanical properties. Ultraform H2320-006 is an injection molding grade with a melt flow of 3.5 g/10 min. The resin is priced somewhat higher than standard grades and is designed for parts subject to heavy loads and stresses.

Hoechst Celanese Corp., Chatham, N.J., has two new 25% glass-reinforced acetal copolymers that are said to offer greater tensile strength and toughness than similar competing materials. Celcon GC25T is a higher-strength version of Celcon GC25A--said to be the strongest acetal available. The new grade has tensile strength of 20,000 psi and notched Izod impact of 1.8 ft-lb/in. Celcon GC25TF is a higher-flow version with slightly lower strength (17,600 psi) and impact (1.3 ft-lb/in.). Originally developed for heavy-duty truck and bus parts, these grades are said to be sparking interest for a wide variety of applications, including contact with food and potable water.

* ASA: BASF Corp. Plastic Materials, introduced a new granite-look molding and extrusion grade of its weatherable Luran S terpolymer, aimed at pool and spa applications. It costs $2.03/lb tl.

* Nylon 6: Miles has two developmental flame-retardant nylons that contain neither halogen nor phosphorus. Durethan KU 2-2184/15 (15% glass) and KU 2-2184/8 (8% glass) are aimed at electrical/electronic parts. They have specific gravities of 1.68 and 1.64, respectively, and flex moduli of 1.81 million and 1.51 million psi.

* Nylon 46: DSM Engineering Plastics, Evansville, Ind., has a new unfilled extrusion grade of its Stanyl nylon 46. Stanyl TW363 is for tubing, stock shapes, and profiles in applications where nylon 6 and 66 succumb to long-term heat aging.

* PBT: A new series of Valox PBTs from GE Plastics are said to offer up to 50% improvements in flow while maintaining physical properties of GE's standard grades. They're said to minimize costs in connectors and other electrical components by allowing use of up to 50% regrind while maintaining UL 94V-0 at 0.031 in. New grades include three FR products: EF3500 (unfilled), EF4517 (17% glass), and EF4530 (30% glass). Also new is non-FR HF4030 (30% glass).

* PPO/nylon: GE's new Noryl GTX628 is a blow molding grade for under-the-hood uses. It's a lower-cost replacement for Noryl GTX625 and offers lower processing temperatures (500-590 F) and a wider processing window. Lower melt temperatures save downtime for head cleaning.

* PPS/PEI blends: GE also has a pair of new polyphenylene sulfide/polyetherimide blends for surface-mount connectors and other electronic parts that require thin walls and high-temperature exposure (e.g., soldering at up to 500 F). Although a mix of crystalline and amorphous plastics, these Supec

blends preserve primarily crystalline character. They're said to give high flow and no flash. The first two grades are Supec SD003 and SD005 with 30% and 40% filler. Prices are $6.25 and $6.05/lb, respectively.

CONDUCTIVE COMPOUNDS

A variety of new conductive and high-temperature thermoplastic grades were launched by RTP Co., Winona, Minn. EMI 330 FR Series are flame-retardant PC EMI/RFI compounds containing stainless-steel fibers. EMI 2580 FR is a flame-retardant PC/ABS alloy also for EMI/RFI shielding. It contains nickel-coated graphite fibers. EDS 300 EM is a flame-retardant, static-dissipative PC containing up to 20% glass. ESD 2580 is a conductive PC/ABS with carbon fiber, also available in a FR version. New PermaStat compounds include ABS, PE, acrylic, and PC/ABS grades.

METAL INJECTION COMPOUND

BASF Corp., Wyandotte, Mich., has added a tungsten carbide acetal compound to its line of metal and ceramic injection molding (MIM and CIM) materials. These compounds are molded, oven baked to pyrolize the plastic binder, and finally sintered to consolidate the metal.

TP ELASTOMERS

Three new families of thermoplastic elastomers based on Shell's Kraton styrenic block copolymers have been launched by GLS Corp., Cary, Ill. The Dynaflex line includes 13 new grades with applications the food, medical, hardware, and consumer markets.

The Dynaflex line is priced in the range of $1.50-$2/lb tl. Dynaflex G-7700 is the higher-performance line, offering six injection molding and extrusion grades with Shore A hardness values of 31-90. G-7700 materials are said to provide superior flow and surface characteristics compared with standard TPEs.

Dynaflex G-6700 and G-2700 are two injection molding series in the 5-90 Shore A range. They are suitable for medical and food-contact applications. G-6700 TPEs are suitable for soft-touch grips. The G-2700 grades are transparent or translucent.

GLS executives said the company soon will unveil four new wire and cable grades, also based on Kraton, all with UL 94V-0 flammability ratings. In addition, GLS is developing new TPEs (patent pending) that will alloy the Kraton polymer base with Dow Plastics' new Engage polyolefin elastomers derived from Insite metallocene catalyst. Two such TPE compounds are aimed at replacing flexible PVC in lawn and garden tool grips. According to GLS, XU-4 (43A, 0.87 g/cc) and XU-6 (58A, 0.88 g/cc) offer some unique surface characteristics, such as improved wet grip. Both are translucent in color.

DSM Thermoplastic Elastomers Inc., Leominster, Mass., has introduced new grades in its Sarlink 4000 olefinic TPE series designed for blow molded, injection molded, and extruded underhood automotive parts. The new grades, Sarlink 4175 and 4180, have hardnesses of 70-90A as well as superior chemical and fuel resistance and heat-aging property retention. A wide service-temperature range is reported. The two grades are still in the test-marketing phase. In addition, DSM is now testing another grade in the 4000 series, Sarlink 4139, which has a hardness reading of 40D.

J-Von, Leominster, Mass., featured its new styrenic TPE, Hercuprene S2954, designed for overmolding or coinjection molding with engineering resins such as ABS or ABS/PC alloy, as well as PS, PP, and PE--without the use of adhesives. The new 11.5 MFR, 47A compound has 0.99 g/cc density and is designed for such uses as grips, buttons, and knobs.

TPUs FOR WIRE & AUTOMOTIVE

BFGoodrich Co.'s Specialty Chemicals Group, Cleveland, unveiled a line of non-halogen flame-retardant Estane TPU compounds, said to provide superior flame resistance and low smoke in applications such as wire and cable. The compounds have a UL94 V-O rating and an oxygen index of 53%--reportedly the highest of any non-halogen TPU. Applications include cable jacketing, conduit, and film laminates.

BFGoodrich also introduced a new addition to its line of Estaloc glass-reinforced TPUs: Estaloc 60204 TPU alloy for auto body side moldings, rocker panels, and trim. It has a notched Izod impact of 18 ft-lb/in., flexural modulus of 220,000 psi, and one of the lowest thermal-expansion coefficients of any thermoplastic, the company claims.

Miles has a developmental polyether-polyester TPU called Desmopan KU2-8651. It's a 75A grade for injection and extrusion.

STYRENIC COPOLYMER

A new developmental KK36 grade of K-Resin styrene-butadiene copolymer from Phillips Chemical Co., Bartlesville, Okla., is aimed at flexible films for food and candy. The new grade will compete with cellophane and PP films. K-Resin KK36 can be processed by blown or cast methods in monolayer film or as a multi-layered structure mated with polyolefins.

FR-HIPS FOR TVs

Dow Plastics introduced a new flame-retardant, high-flow HIPS for tv cabinets that's said to offer improved processing and performance features in both existing as well as new larger designs. Styron 6010 IRPS resin is said to be a good choice for low-pressure or gas-assist injection molding, which requires high flow--in this resin, 10.2 MFR. Notched Izod impact is 2.3 ft-lb/in.

STIFF/TOUGH PPs

Himont, Inc., Wilmington, Del., featured its new family of high-flow PP copolymers for injection molding that offer a good balance of impact strength and stiffness. For larger automotive parts (i.e., pillars, sliding doors) is 35-MFR Pro-fax SD-242. Drop-weight impact strength at -20 F is 17 ft-lb and flexural modulus is 200,000 psi.

Another new 35-MFR material is Pro-fax SC-854, aimed at toys, housewares, and appliances. Key properties include a flexural modulus of 190,000 psi, HDT of 446 F at 66 psi, notched Izod value of 1 ft-lb/in., and drop-weight impact of 15 ft-lb at -20 F.

Also new is high-flow Pro-fax SG-702 copolymer with low-temperature impact strength for use in injection molded durable goods such as automotive interior trim, infant car seats, and cooler liners. Flex modulus is 150,000 psi and HDT is 185 F at 66 psi. Notched Izod impact is 3 ft-lb/in. and drop-weight impact at -20 F is greater than 45 ft-lb.

Also from Himont is a new impact PP copolymer, Pro-fax SC-914, for thin-wall injection molded packaging. Himont says this 70-MFR material may be the only commercial injection molding resin that can fill production tooling with a length-to-thickness ratio of 400:1 and still meet impact and top-load requirements. Up to 40% lower weight reportedly can be achieved by using this material in place of high-flow HDPE. Properties include flexural modulus of 190,000 psi and HDT of 469 F at 66 psi. Drop-weight impact strength is 6.7 ft-lb at -20 F.

KS-059P, a new propylene copolymer made by the new Catalloy process, was also featured by Himont. This 10-MFR material reportedly offers outstanding impact strength--no break in notched-Izod testing at room temperature. The material was chosen for a golf practice mat over ionomer and plasticized PVC, owing to its durability and moldability.

Himont introduced a new family of high-clarity PPs for extrusion blown and injection-stretch-blown bottles. Included is Pro-fax SR 857M, a 35-MFR clarified random copolymer for stretch-blow molding. The material is said to have exceptional clarity and toughness. Notched Izod impact is 0.9 ft-lb/in. at room temperature and drop-weight impact at 40 F is 12 ft-lb. It is positioned to compete with PET in packaging for sports drinks and other hot-fill, non-carbonated products. It is also targeted to compete with PET and PVC in clear liquid detergent bottles. Pro-fax SR 857M has also been used for injection molded thin-wall deli containers.

PP VS. ABS

Ferro Corp.'s Filled and Reinforced Plastics Div., Evansville, Ind., introduced PP alloys (patents pending) to compete with ABS in auto and appliance parts. They offer similar shrinkage, allowing them to be used in ABS tools. Besides better chemical resistance than ABS, new DPP 30 UY (30% filled) reportedly offers similar practical toughness at a 10-20% cost advantage over ABS. Mineral-filled FPP 30 GQ has better strength, stiffness, and heat resistance than ABS, with slightly lower impact strength, at a 15-25% cost savings.

Colonial Plastics, Dyersburg, Tenn., has a new talc-filled PP that's said to compete cost-effectively with PC/polyester. Colonial XP4561-3 has a flex modulus of 246,000 psi and notched Izod of 9.5 ft-lb/in.

NEW CPVC COMPOUNDS

BFGoodrich Co.'s Specialty Plastics Group, Cleveland, introduced TempRite LC low combustibility CPVC compounds. They're available in profile extrusion and injection molding compounds, as well as in thermoformable sheet. They meet or exceed FAR 25.853, FTA/UMTA, and Model Building Code Class A or 1 specs for commercial aircraft and mass-transit interiors, building plenums, and commercial or institutional interiors. Sheet products thermoform similarly to ABS and offer deep-draw capability with excellent texture retention.

Other additions to the TempRite CPVC line are the first two products in a series of high-performance custom injection molding compounds. TempRite CIM215 and a version with enhanced weatherability, CIM215W, have HDTs of 215 F and high melt flow. They have been flame tested at UL 94-5VA.

NPE News Wrap-Up: Recycled Resins

GE Plastics, Pittsfield, Mass., has launched six new engineering thermoplastics, each containing a minimum of 25% pre- or post-consumer recycle content. Each grade is designed to mimic the properties of a particular prime resin, although the recycled grades are not recommended for applications with demanding color tolerances or processing conditions. Availability is limited, based on recycle feedstock supply.

* Two black injection molding PC grades include Lexan REL340 and REL350. Both have a melt-flow rate of 15 g/10 min. REL340 is a g-p grade with properties similar to Lexan 221 virgin PC. REL350, geared for automotive applications such as instrument panels and headlamp reflector bodies, is similar in performance to virgin Lexan EM3110R.

* Cycolac REC550 is a g-p medium-impact ABS (black or gray) developed for use in computer housings and auto interiors. It's comparable to Cycolac GPM5500 and GPT5500.

* Xenoy REX165 is a black PC/PBT alloy created from salvaged Ford bumpers made from Xenoy 1102. It's used to make taillight housings for Ford's Taurus and Mercury Sable wagons.

* Cycoloy REY295 is a flame-retardant ABS/PC for computer and business-equipment housings that resembles Cycoloy C2950HF. It meets UL 94V-0 at 0.063 in. and 94-5VB at 0.100 in. It's available in a limited range of custom colors.

* Noryl REN814 is a PPO/PS alloy, which is used in injection molded roofing shingles. It has a minimum notched Izod value of 2.2 ft-lb/in. and HDT of 210 F at 264 psi.

Several new recycled-resin developments were announced at the show by MRC Polymers, Inc., Chicago. First, MRC received UL 94V-0 classifications for four of its Naxell recycled polycarbonates, including unfilled and 10% glass-filled grades in medium and low viscosities. These products reportedly can replace their virgin equivalents at 10-30% cost savings.

MRC also has introduced "controlled-rheology recyclate" with viscosities customized for particular applications. "CR" grades are available in its Naxell PC, Stanuloy modified polyester, and Emarex modified nylons.

Silicones for LIM

GE Silicones, Waterford, N.Y., introduced eight new liquid silicone elastomers for liquid injection molding (LIM). These include five new clear grades, LIM 6030, LIM 6040, LIM 6050, LIM 6060, and LIM 6070, with Shore A hardnesses ranging from 30 to 70, respectively. They are all U.S.P. Class VI tested and FDA compliant for food contact, GE says.

Also new is LIM 6745-D2, a high-flow, 45 Shore A grade for keypads. It requires no post-baking, and parts can be demolded automatically with very low hot-tear rates.

LIM 2660 FR is a new 60A grade that is rated UL 94V-0 and aimed at anode caps, gaskets, and business-machine parts.

A new automotive gasketing masterbatch, LIM RG-1 is designed for use with GE's new 6000 base series at 1-5% loading.

High-Flow PP/Glass Stampable Sheet

A new 40% glass-filled composite of PP and continuous-strand mat boasts over 10% improved flow into hard-to-fill bosses, ribs, and tabs. Azdel PD1 1311 sheet also reportedly improves painted surface quality. It has the same impact performance as standard Azdel--12.3 ft-lb/in. notched Izod.

The material was developed in conjunction with Chrysler Corp. and custom molder Lescoa Inc., Grand Rapids, Mich. The new sheet is being used for knee bolsters in the 1994/95 Chrysler LHS and New Yorker.