Image appears to show part of the backwash process when preparing dyed wool tops for gilling and recombing. The wool top slivers are fed into two or three bowls, the first bowl containing warm soapy water, the latter bowls warm water in order to rinse. Slivers pass though squeeze rollers and then into a dryer and dried to a specific moisture content, on exiting the dryer slivers are lubricated in order to reduce static and fed into a Gill box machine to begin the fibre parallelisation process. Backwashing is also sometimes used after the Carding process prior to first combing, it is a secondary wash and gives the end product a much cleaner result. Source: Greg Aldrige35mm coloured slide in presentation folder with wool sample set no 447. 6wool processing, top making, card clothing, combing, backwashing, gilling, slivers