Pulsed laser scalloping of decorative lace

Abstract

Decorative lace is knitted in webs typically 3 metres wide containing many smaller lace ribbons. These lace ribbons must be separated from the main web before sale to the garment manufacturers and retail trade. The separation process for decorative lace is traditionally carried out using scissors or a guided knife cutting system. The development of a machine vision guided laser cutting system at Loughborough University in the 1990s demonstrated that an economical fully automatic cutting system could replace the slow and expensive traditional methods. Incorrect positioning of the continuous wave laser beam focused spot can cause melting and subsequent hardening to the lace edge, which can feel harsh on the skin of the garment wearer and is a quality issue in some market sectors. In order to address this quality issue a high-accuracy pulsed laser cutting solution has been investigated, resulting in a fully automatic, vision guided, pulsed laser cutting process for lace in the form of a low-speed demonstration system. The lace produced on the pulsed laser system has been shown to have a significant improvement in edge quality over lace produced using the continuous wave laser cutting process. The edge quality produced by the pulsed laser cutting process approaches that of traditional mechanically cut lace with the potential for vastly increased output with lower operational costs.