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Chemical and physical properties of various plastics used for plastic abrasive applications are presented. All testing is done in compliance with MIL-P-85891 (AS), “Plastic Media for Removal of Organic Coatings”. Density and heavy density particle contamination are particularly important tests relative to aerospace applications.

Over the past 15 years, “Kapton” polyimide film has been adopted as the principal wire and cable insulation in over 70 military and commercial aircraft, missile and space vehicle applications. This wide acceptance is due to the unique combination of properties found in “Kapton”: low weight, low smoke toxicity, high dielectric strength, toughness, chemical resistance and the ability to withstand extremes of temperature. This paper describes the key steps in the manufacture of wire and cable insulated with “Kapton”. It reviews the latest in shop handling techniques including automated stripping and high speed marking. Additional aerospace applications will be discussed in avionics and insulation blankets.

Thermal and chemical processes occurring in exhaust manifold thermal reactors have been closely simulated with a computer model. The model has been developed to predict the performance of thermal reactors operating on multicylinder engines in vehicle service. Output predictions include both transient and steady-state response including reactor warmup at steady-state engine operation. Gas and metal temperatures, heat fluxes, and concentrations of selected exhaust components can be followed as a function of time at various locations within the reactor. Studies carried out using the model indicate that, for the chosen set of operating assumptions, combustion of hydrocarbons and carbon monoxide at steady-state operating conditions is limited by imperfect mixing of exhaust gases with auxiliary air. Most reaction was found to occur in the exhaust ports and inner chamber of the reactor with little additional combustion downstream of these sections.

“DELRIN” is a new thermoplastic which offers high strength, excellent thermal stability, good fatigue life, low creep, and excellent solvent resistance. This paper describes the physical and chemical properties of the material, and the range of possible uses. The material is easily fabricated into complex shapes by standard injection-molding techniques. Also, it can be easily joined to itself or to other materials. The authors think that the material offers advantages over metals in its good fric-tional properties, abrasion resistance, and corrosion resistance.