Advances in Laser Welding for High-Performance Polymers

Laser transmission welding (LTW) joins a near-infrared-transparent top part to an absorbing lower part, melting only the interface so internal electronics stay protected — a gentler method than ultrasonic welding. The difficulty is that high-performance, heavily filled PBT, PPS and high-temperature polyamides tend to absorb the beam and carbonize. The white paper describes material developments that restore transparency and widen the welding window: Pocan PBT grades (for example a 30% glass-fiber grade exceeding 25 MPa weld strength through 2 mm, plus hydrolysis-resistant and PBT/PC-blend variants), ForTii (a semi-aromatic polyamide, PPA) whose crystalline morphology keeps it transmissive even at 50% glass fiber, and Xytron PPS reaching about 20 MPa through 1 mm. It then introduces absorbing-to-absorbing (ATA) welding, which uses two lasers to heat each opaque part before joining, enabling complex 3D geometries, color-matched parts and heavily filled materials — demonstrated on impact-modified PPS with 40% glass fiber at over 50 MPa through 1.5 mm. For product teams, this removes long-standing trade-offs between weld strength, geometry and appearance, supporting reliable hermetic sealing in high-volume production; end-of-life disassembly of these sealed parts is noted as an open challenge.   **About this podcast** — Made for engineers and product development teams, these easy-listening episodes explore practical engineering challenges and the material choices behind them — giving you insight you can put to work in your own designs. At Envalior, we help you reduce time, cost, risk and CO₂. The goal is simple: to help you select and process the right material more easily, and to deliver solutions with proven impact in the real world. More information: www.envalior.com