Stevens Urethane Helps Automotive Protective Film Last For Years

High Gloss and Clarity Keep Cars Looking Good

Strongsville, Ohio — New StoneShield™ protective automotive film from Avery Dennison, Industrial Automotive Products North America, taps the inherent toughness and UV light resistance of Stevens Urethane aliphatic TPU film to produce a long-lasting, aesthetically pleasing finish. StoneShield film is typically applied along the front edge of a vehicle’s hood, its bumpers and rocker panels, as well as around key locks and door handles, and anywhere else needing protection from stone chips, abrasion, and minor impacts that mar a vehicle’s finish.

StoneShield consists of clear 8 mil sheets of aliphatic thermoplastic polyurethane, with pressure sensitive adhesive and a release liner applied to one side. Avery Dennison uses a proprietary heat treating process to bring out an exceptionally high gloss level on the film, which complements the clear coat finish on most of today’s vehicles.

“There is more interest in the market for higher end protective films, and demographics support this,” said Eric Petersen, director of sales and marketing for Avery Dennison/IAPNA. “People are spending more money on their cars, and are willing to invest a little more to keep them looking good. Compared to the overall cost of the vehicle, a product like StoneShield is cheap insurance against dents and chips in the finish.”

Performance requirements for StoneShield protective film demanded a tough, durable material that would not yellow or crack even after years of exposure to weather and sunlight. Stevens aliphatic TPU is inherently light stable, and strongly resistant to degradation from ultraviolet light, as well as being unaffected by weather and temperature variations. Additionally, aliphatic Stevens Urethane offers superb optical clarity, with high light transmission rates of up to 94% and low haze levels of less than 1%, so the color of the vehicle finish shows through clearly. StoneShield also benefits from the inherent toughness and durability of Stevens Urethane. TPU offers excellent abrasion resistance and high tensile strength, so it easily withstands the rigors of the road. TPU’s low temperature flexibility ensures reliable protection at temperatures as low as -30°C.

“Yellowing and outdoor durability are the real performance issues,” noted Petersen. “Long term clarity is a must. You don’t want your invisible protection to turn yellow after a couple of years. Testing shows that StoneShield is outperforming everyone else on the market. Life cycle testing takes a while, but we have more than five years in accelerated weathering tests, and we’re still very happy with the clarity.”

The gloss level of the film’s finish is another important consideration. “We don’t want a dull, matte look, which can happen in a matter of weeks with the wrong material,” Petersen noted. Most cars today sport a high gloss, clear coat finish, and Avery wanted the StoneShield to blend in as seamlessly as possible. Avery runs the Stevens Urethane through a proprietary heat treating process that improves the gloss level of the film. After five-year weathering tests, the film still retains the desired gloss appearance.

“Our new StoneShield represents a significant improvement in automotive protective films,” said Petersen. “We knew we wanted TPU because of its flexibility, and research confirmed that its UV resistance and durability combined to make it the best thermoplastic material we could find. Stevens Urethane gives it long-term UV resistance, so it retains its clarity and high gloss finish for many years.”

StoneShield is sold into the automotive aftermarket, to professional restylers working at dealerships and reconditioning shops to “upfit” cars with sunroofs, ground effects, as well as protective films such as StoneShield. Avery Dennison sells StoneShield in bulk rolls 12-inches, 18-inches, and 24-inches wide by 40 and 120 yards. The restyler cuts the film to size using a plotter similar to those used in the sign making industry. Many OEMs offer specific patterns to suit individual vehicle designs.

Stevens Urethane offers several grades of aliphatic TPU sheet with different melt characteristics, modulus, thicknesses and sheet widths. All aliphatic Stevens Urethane is manufactured and packaged in Class 10,000 clean zone environments to ensure delivery of the highest possible quality optical grade aliphatic sheet with no contamination.

Based in Easthampton, Mass., Stevens Urethane manufactures a full range of high-performance urethanes for use in a wide variety of "can't fail" applications for consumer, medical, commercial, and industrial markets. Stevens Urethane is the only company in the world to offer urethane in blown film, extruded sheet, tubing, cord, and profile form.

For additional information, contact: Stevens Urethane, 412 Main Street, Easthampton, MA 01027. Phone: (413) 533-8100, or toll free at 1-877-TPU-FILM (1-877-878-3456). FAX: (413) 552-1195. E-mail: info@stvure.com. Stevens Urethane is a business unit of JPS Elastomerics.

For information on StoneShield, contact Eric Petersen, Avery Dennison, 17700 Foltz Industrial Parkway, Strongsville, OH 44136. Phone: (440) 878-7266.