TWI Industrial Member Report Summary 946/2010
By A Brun and M Gallegillo
Through-transmission laser welding of plastics uses a near infrared laser radiation to weld plastic workpieces. It requires both a laser transmissive and laser absorbing workpiece, or an absorbent layer at the interface. Most plastics transmit light in the near infrared range and to make the plastic absorbent, carbon black or a Clearweld® absorbent is added to the resin of the materials, alternatively, a Clearweld absorber is applied at the interface.
Through-transmission laser welding is used in industry for applications such as photographic tank and automotive parts, and has been demonstrated for more applications such as fuel cells, medical devices and technical textiles. However the fact that a clamping pressure needs to be applied during the process can limit its use in industry to simple geometries. Several clamping systems have been developed for this process but no study has been done so far on comparing different approaches.
During the through-transmission laser welding process, only a small amount of material is melted at the interface which may not be enough to compensate for irregularities of the parts.
- Determine the pressure distribution applied by a sliding clamp used for through-transmission laser welding.
- Study the effect of clamping pressure on the strength of the weld for both a sliding and fixed clamp system.
- Investigate the effect of irregularities in the workpieces on the through-transmission laser welding process.