Aplicação de termoplástico de poliuretano (TPU) como elemento de proteção para diminuir danos superficiais em componentes automotivos

Abstract

The surface integrity of painted components is essential to ensure product quality and reduce losses caused by rework and scrap. In an automotive production line, surface defects such as scratches and impact marks were identified due to contact between the metal hanger used for transporting the parts and the painted components, compromising their surface finish. To address this problem, this study aimed to develop, optimize, and validate a Thermoplastic Polyurethane (TPU) device manufactured by 3D printing to eliminate direct contact between rigid surfaces and preserve the integrity of the painted coating. Initially, the production process was analyzed by inspecting 120 components, in which 14 cases of surface defects associated with mechanical contact were identified. Based on this assessment, the required material properties were defined, including tensile strength, hardness, abrasion resistance, resilience, and energy absorption capacity. TPU was then selected as the most suitable material, and prototypes were manufactured using additive manufacturing. The prototypes underwent successive optimizations involving geometry, infill density, surface roughness, and fastening system to improve their mechanical performance and operational stability. After implementing the proposed solution, an additional 1,000 components were evaluated, and no cases of scratches or impact marks were observed. Furthermore, the device maintained its structural integrity throughout the evaluation period, demonstrating its durability and suitability for industrial applications. The results indicate that combining TPU with additive manufacturing enabled the development of a low-cost, easy-to-implement, and effective solution for protecting painted components, contributing to improved quality and reliability in the manufacturing process.