Abstract: A web threader assembly comprises at least one flexible stainless steel belt to which the leading edge of a web can be detachably affixed. The belt is conveyed through a web path extending through the dryer or other machine in which the web travels, is guided by a plurality of pulleys and tensioning devices, and is positively driven through the dryer or other web processing machine by its own drive system. The belt is extremely thin and thus permits tight sealing of the dryer or other machine requiring a threading operation and also requires no lubrication, and also can be easily cleaned and thus can be used in sterile environments. If the threader is to be used with a relatively wide web, two spaced apart belts are preferably provided and connected threader bar to which the web is attached. An electronic control system monitors operation of the threader assembly and terminates operation of the threader assembly upon breakage or jamming of the web or the belt.