The development of test procedures for controlling the quality of the manufacture of engineered compression stockings

摘要

A new technology platform known as 'Scan2Knit' was invented in the William Lee innovation Centre of the University of Manchester to engineer and manufacture compression stockings for the treatment of venous disease in a Welcome Trust funded research project. The intellectual property of the above technology has been licensed for commercial exploitation by the University.The graduated pressure profile that is necessary for the treatment of venous ulcers is generated with the engineered compression stocking, and will depend on the stitch length of the knitted fabric structure and an empirical pressure profile database. The 'Scan2Knit' technology was developed to produce an engineered compression stocking on a 18 gauge Stoll CMS computerised flat-bed knitting machine utilising a microprocessor controlled precision positive yarn delivery system to guarantee the delivery of a predetermined stitch length to the knitting needles. However, the licensee of the technology has decided to manufacture engineered compressions stockings by using 14 gauge Stoll CMS flat-bed knitting machines instead of gauge 18 machines due to commercial advantages. Therefore, the main aim of this work is to investigate the transfer of 'Scan2Knit' technology on to a coarse gauge manufacturing platform to produce engineered compression stockings. The investigation focuses on two vital requirements of 'Scan2Knit' technology; the analysis of the performance of the precision positive yarn delivery system on the new production platform and the evaluation of the functionality of the knitted structure produced with it. The objectives of the research are to develop test procedures for the evaluation of the three dimensional pressure characteristic of compression stockings manufactured on the new production platform, and the performance of the precision yarn delivery system. To produce the engineered compression stockings with the 'Scan2Knit' technology, it is essential to determine the interface pressure that the knitted structure would impart on a particular radius of curvature at a predetermined strain percentage which is attained with an empirical database. Hence, a key objective of this study is to develop a methodology, which is efficient and user friendly, for the generation of the empirical pressure profile database required to engineer the interface pressure profile of a compression stocking.It is envisioned that the manufacturer of the engineered compression stockings would benefit by the knowledge generated within this research, and develop their own quality assurance procedures to guarantee that the compression stockings are produced to deliver the graduated pressure profile prescribed by the clinician for the treatment of venous ulcers.