Quality Repair Strategies for Thermoplastic Automotive Exterior Body-Panels

This paper proposes and demonstrates a repair strategy for “Thermoplastic-Substrate/Coating Composite” body panels. A systematic approach is presented that allows automotive design and material engineers to evaluate polymer repair systems and test their compatibility and long term durability with thermoplastic body panel substrate materials (figure 1).

This paper systematically categorizes the degree of thermoplastic body panel damage into four specific levels: (1) abrasion of the coating without substrate damage or penetration, (2) damage to the surface coating and substrate excluding cracks or punctures, (3) small cracking or punctures, (4) massive coating/substrate damage beyond that which could be feasibly repaired.

Repair systems were evaluated by focusing on substrate preparation techniques to optimize adhesion characteristics without adversely effecting the impact behavior. The adhesion quality was evaluated with tensile lap-shear testing and practical observation techniques applied to actual repairs.

The strategies proposed in this paper resulted in a quality repair procedure for thermoplastic body panels and a cost-effective alternative to panel replacement.