Needlefelts coated with PTFE membranes are routinely used in dust collectors, but expanded PTFE membranes can suffer damage under harsh operating conditions. Embedding the membrane within the carrier medium appears to overcome this problem. Simon Gibbons, technical manager of Ravensworth Ltd, UK, discusses the company development of embedded PTFE filter membranes and outlines some of the key benefits of having the membrane located within rather than on top of the textile support.