Laser Fusion to Impart Cohesion to Textured Filament Yarns

The conventional intermingling process uses a high-speed air jet, positioned in the path of the yarn being textured; to create knot-like intermittent entangled nodes (‘nips’ or ‘tacks’) in the textured thermoplastic continuous multi-filament yarn. This paper reports a proof-of-concept research into the use of a pulse laser to fuse such yarns at discrete points at regular intervals along its length to impart cohesion at required frequencies. Pulse frequency and duration, hence the heat intensity, are varied to determine a suitable range of operating conditions. Results from a range of polyester and nylon yarns show that fusing textured filament yarn to create nips is feasible using a pulse laser as an alternative to intermingling by air jets. The multifilament yarn is also modeled to compute the heat flow in the yarn when heated by a pulse laser. This model can be used, as a tool to estimate the heat energy required to fuse a given textured yarn.