New Coating Developed for AMODEL(R) Polyphthalamide from Solvay Advanced Polymers Provides Thermal Protection in High-Heat Applications
Thin film prevents surface oxidation and deterioration of properties
ALPHARETTA, Ga., Oct. 7 -- A new coating provides thermal reflectivity when applied to the surface of parts made of AMODEL(R) polyphthalamide (PPA) from Solvay Advanced Polymers, L.L.C. The product has been developed by Tech Line Coatings, Inc. of Murrieta, California, and is based on technology used in the company's IC(TM) family of coatings for metals. Designated IC-105, this coating is the first designed by Tech Line specifically for application to plastic.
In testing conducted by Tech Line and Solvay Advanced Polymers, sample plaques coated with a thin film of IC-105 were subjected to direct contact with a heat source at 600 degrees F. After extended exposure, the temperature of the plastic in the samples was measured at approximately 400 degrees F.
Higher heat in underhood applications
The differential of 190 to 200 degrees F is significant for plastics such as polyphthalamide that are intended for use in the components of an automobile powertrain. "While plastics such as nylons, or polyamides, or amide-imides have excellent qualities within a certain temperature range," says Leonard Warren, president of Tech Line Coatings, "almost all of them have difficulties going above 500 degrees F for extended periods of time. They begin to lose their primary characteristics at this temperature -- and certainly above 550 degrees F."
Warren, whose company specializes in coatings for the high-performance automotive market, points out that higher temperatures are coming to the underhood environment as part of an evolutionary process. "Advances in engine technology, fuel management, and emissions requirements are driving up the heat. Where these types of plastics were adequate a few years ago, today that's no longer the case."
At the same time, the economics of the automotive industry are creating pressure for the use of plastic as a replacement for metal. Part consolidation and the elimination of post-finishing processes make plastics an attractive alternative to some metals.
Jim Doty, a global marketing manager at Solvay Advanced Polymers, cites applications in an engine's air-induction system where materials such as AMODEL PPA are replacing aluminum. "The end tanks of turbocharger air cooler housings, for example, are sometimes made of plastic. But extended operation at elevated temperatures can have serious consequences for parts like this."
In contact with high-temperature air, the surface of these parts can undergo oxidation. As a result, the charred plastic can flake off, and, along with exposed reinforcing fibers, can contaminate the turbocharger system.
Coating eliminates oxidation, prevents deterioration
In test conditions of 410 degrees F, however, samples of AMODEL PPA showed that the IC-105 coating practically eliminated oxidation. "We didn't see the charring that leads to contamination, and we don't see the surface deterioration that can have negative implications for airflow," points out Doty. "And we anticipate that the 190-200 degrees F temperature differential will forestall the degradation of such key properties of the polyphthalamide as tensile strength, elongation, stiffness, and impact resistance.
"This coating technology improves the window of opportunity for AMODEL grades to be used in higher-temperature applications, not only as a replacement for aluminum, but as an alternative to much more expensive polymers such as PEEK (polyetheretherketone)."
In the production process, a part would be molded and then the coating would be sprayed onto the surface and allowed to cure by air drying for a short period. Or a part could be dipped in the coating after forming. "Adhesion is excellent," says Warren. "In formulating this product for use with AMODEL PPA, we had three major goals -- adhesion, thermal reflectivity, and sealing -- and we were able to accomplish them all." He adds that "Ideally the coating would be 100% water-based, but the amount of solvent in the formulation is very small, so the VOC (volatile organic content) is still very low."
About Solvay Advanced Polymers
Solvay Advanced Polymers, L.L.C. is a subsidiary of Solvay America, Inc., the U.S. holding company of Solvay S.A. The company produces high-performance polymers that are used in a wide range of demanding applications in the automotive, aerospace, industrial, foodservice, medical, and electronics industries worldwide. More information about this and other Solvay Advanced Polymers products and services can be found on the company's website at http://www.solvayadvancedpolymers.com/ .
Solvay is an international chemical and pharmaceutical group with headquarters in Brussels, Belgium. It employs more than 30,000 people in 50 countries. In 2003, its consolidated sales amounted to EUR 7.6 billion generated by its three activity sectors: Chemicals, Plastics and Pharmaceuticals. Solvay is listed on the Euronext 100 index of top European companies. Details are available at http://www.solvay.com/ .
About Tech Line Coatings, Inc.
Tech Line Coatings, Inc., was established to bring the advantages of aerospace coating technology to the automotive high-performance aftermarket. Since 1986, the company has been in the business of applying or developing products for exhaust systems, brake systems, cooling systems, and internal or external engine parts. The company enforces a rigorous testing program, both in the laboratory and on the track, to assure that its coatings will meet the highest standards.
Tech Line Coatings has its headquarters in Murrieta, California. It serves its customers from distribution facilities in Murrieta and in Midlothian, Texas.