New engineering resins: Outpouring of of ideas ideas

When considering today’s engineering resins industry, comparisons to Hollywood may not, at first, seem particularly relevant. But there are more similarities between the two than you might think: for key players in both, resilience, the ability to withstand heat (gossip and bad reviews in Hollywood, literal heat in the engineering resins industry), the financial bottom line and, of course, weight loss are crucial to achieving success.

Valued for their temperature resistance, strength, dimensional stability and chemical resistance in demanding applications, engineering resins are make-or-break components in the production of a wide variety of North American markets. But perhaps none more so than the automotive industry, which remains under ever increasing pressure to manufacture parts that are lighter, and thus more fuel efficient, without sacrifice of strength and durability.

“The automotive market is still very much focused on weight savings through metal replacement, and in achieving greater temperature resistance and durability in automotive-related electrical applications,” Fred Boss, product manager DSM Stanyl in Southfield, Mich., said.

And although replacement of metal with thermoplastics began decades ago, the process is still far from complete. Engineering resin suppliers continue to develop a host of new materials to help original equipment manufacturers (OEMs) meet evolving safety and emissions standards by making automotive parts, as well as the related electrical/electronic applications, that are lighter, stronger, more temperature-resistant and easier to mold.

NANOCOMPOSITES, NANOPARTICLES

More and more, this quest involves developments at the nanometer scale. DuPont, for example, is set to introduce its first line of thermoplastic nanocomposites, which promise to open new opportunities for the design and production of lighter, higher performance auto parts.

According to Dr. Nandon Rao, vice president, technology for DuPont Performance Materials in Wilmington, Del., small amounts of the company’s DNM nanomaterial in a polymer can produce substantial property improvements. He cited an example in which the addition of only 1.5 per cent of DNM in glass-reinforced polyethylene terephthalate (PET) resulted in improvements in heat deflection temperature of between 10 and 15 Celsius (C) over typical glass-reinforced PET. “The DNM material can also be combined with glass fibres to produce composites with equivalent properties but that are lighter in weight than resins using only glass for reinforcement,” Rao said.

A breakthrough may have been achieved recently by Bayer MaterialScience (BMS), which has introduced its Bayblend FR 3000 injection molding grades polycarbonate (PC)/acrylonitrile butadiene styrene copolymer (ABS) blend — the industry’s first FR-PC/ABS blend with nanoparticles, according to the company. “The Bayblend FR 3000 resins are designed to meet the interest for lighter weight, lower maintenance thin-wall parts not only for the automotive sector, but for the public transport sector — subway cars and applications like that,” Ernie Springolo, senior country representative for BMS Canada in Toronto, said.

COMBATING HARSH ELEMENTS

GE Plastics has recently made available its new line of Extem thermoplastic polyamide (TPI) resin, designed to facilitate the increasing demand for easy-to-produce parts that can withstand high temperatures and harsh chemical environments.

Melt processable on traditional extrusion and molding equipment, Extem TPIs can withstand continuous use temperatures up to 230C, and glass transition temperatures up to 310C. “[Traditionally,] customers needing an ultra-high-performance plastic were forced to choose between expensive imidized thermosets with high processing costs or high-performance semi-crystalline resin,” Brian Herrington, general manager of GE’s high performance polymers in Pittsfield, Mass., said. “New Extem resins help solve these challenges through top-of-the-line extreme performance, cost-effective processing and the elimination of such secondary operations as post-molding curing or crystallization.”

POLYPROPYLENE PITCHES IN

A key component of OEMs staying competitive in the face of growing competition and lower margins lies in not spending more to produce a given part than is absolutely necessary, an increasingly difficult goal given today’s skyrocketing resin prices.

For OEMs producing automotive applications that would be over-engineered using expensive grades of polypropylene (PP), BASF has introduced a budget Neopolen P grade expanded polypropylene (EPP). Traditionally considered a commodity resin, PP is increasingly coming to occupy the grey area between the commodity and the engineering grades, and is being used in lieu of engineering resins in various auto applications.

According to Michael Gragert, global business management at BASF in Ludwigshafen, Germany, the company’s P 7230 grade targets markets where a less-expensive grade satisfies a lower demand profile. “Neopolen P 7230 can be used as a filling material if high shock and energy absorption is not as important, thereby offering considerable cost savings,” he said.

BLENDING TOGETHER

Collaboration between two Florence, Ky.-based companies, Ticona and Topas Advanced Polymers, has resulted in a new blend combination of Ticona’s Celstran PP material and Topas’ ethylene and norborene-based COC resin. The result, according to Ticona, offers significantly lower warping and far better surface properties for various automotive applications than conventional long-fibre materials.

“Trials with this compound by an automotive supplier have shown that the dimensional accuracy of a complex structural component can be improved from a tolerance of 4 mm to less than 0.5 mm,” Ticona said. “The compound ingredients — PP, glass fibres and COC — are readily miscible, allowing different formulation variants to be supplied according to the application and part requirements.”

According to Ticona, the material combination provides optimum surface properties for parts such as sunroofs, door modules and underbody covers, with lower warping. Better fogging properties and higher scratch resistances are further advantages of the compounds, the company continued.

PEDAL TO THE METAL REPLACEMENT

Amid all of the new engineering resins that provide new degrees of temperature and chemical resistance while trimming cycle times, the old challenge of reducing weight by substituting plastic for metal has not be forgotten.

Weighing up to seven times less than metal, Stanyl 4,6 (PA46) polyamide, from the Stanyl division of Evansville, Ind.-based DSM Engineering Plastics, is designed as a replacement material in such metal or rubber applications as automotive strut mounts, electromechanical anti-vibration and anti-shock mounts, energy-absorption components and exhaust hangers.

“There are significant challenges when selecting the right material for applications with rubber components,” Paul Habets, application developments manager for Stanyl, said. “Manufacturing requires high heat for vulcanisation, and many of the traditionally rubber-to-metal components require very high stiffness and strength. In a rapidly growing number of applications, Stanyl meets or exceeds the mechanical and thermal performance needed for the rigid element in these products.”

Stanyl 4,6 (PA46) exhibits properties suitable for applications that marry a strong substrate to a relatively soft or compliant element: creep resistance, high stiffness and strength, Habets continued, combined with heat resistance to withstand both vulcanisation and application environments, including automotive under-bonnet uses. The material can handle continuous use temperatures as high as 200C with transient peaks of up to 250C. Stanyl 4,6 (PA46) also provides good chemical resistance, particularly to grease, gasoline and oil, he continued. Charpy impact v
alues remain at a high level, even at temperatures below 0C.

SEEING THROUGH IT

While it may seem like something from a science fiction movie, the engineering resin companies are also addressing the incorporation of transparent parts into today and tomorrow’s cars. BMS’ Makrolon PC, for example, has been used to mold the transparent body and parts of the interior of a new see-through concept car manufactured by Swiss auto designer Rinspeed (see Design Ideas, pg. 49).

Developments are still being made that are applicable to auto parts that have always been transparent, such as windshields. Philadelphia, Pa.-based Arkema Inc.’s new Rilsan Clear transparent polyamide resin offers possibilities for auto glass replacement, although to date its use has been limited to signature and sportswear applications in Japan, where the company has a technical centre and strong product development network. According to Anissa Brahmi, Arkema’s optics and industrial market manager, the material is transparent in any thickness and offers high chemical and scratch resistance.

Given ongoing developments designed carve out weight and increase strength and temperature resistance in auto parts, it seems clear that, whether or not one thinks that Hollywood is in decline, the engineering resin companies definitely haven’t lost their drive.

RESOURCE LIST

Arkema Canada Inc. (Oakville, Ont.);www.arkema.ca; 905-847-4767

BASF Canada (Toronto);www.plasticsportal.com; 800-267-2955

Bayer Inc. — Division of Bayer AG (Toronto);www.bayer.ca; 416-248-3067

DSM Engineering Plastics (Evansville, Ind.); www.dsm.com; 800-333-4237

E.I. Du Pont Canada Company — Engineering Polymers Division (Mississauga, Ont.); www.plastics.dupont.com; 800-387-2122

GE Canada (Mississauga, Ont.);www.ge.com; 905-858-5100

Ticona — Division of Celanese AG (Florence, Ky.); www.ticona.com; 859-525-4740

Topas Advanced Polymers — North America (Florence, Ky.);www.topas.com; 859-746-6447