pair of spreader frame sections 11 12 and a series of two or perhaps three spacer bar units 13 arranged for interchangeable assembly with the spreader bar section and each covering a given range of width variation in setting up the equipment for processing fabric of a given width the spreader frame sections are assembled with a spacer bar unit of an appropriate width range when initially assembled the spreader frame would of course be at the maximum width of the range because the gas spring unit 50 would be fully extended the assembled spreader is then positioned between the edge drive rolls 25 26 and the edge drive rolls are then brought together into contact with the radius rolls 16 17 in order to position and support the spreader frame thereafter the spreader may be set to the precise desired width by moving the edge drive rolls 25 26 further inward by appropriate rotation of the threaded shaft 31 desirably adjustable stop means are provided to limit subsequent outward movement of the edge drive carriages such that the edge drive rolls are not separated farther than the expansion limit of the spreader frame assembly any suitable arrangement may be provided for this purpose such as the provision of an adjustable stop collar 58 on the shaft 31 arranged either to stall the motor 32 or to cooperate with a switch or other control device to terminate its motion when a predetermined maximum width limit is reached one of the outstanding advantages of the new apparatus is the ability of the operator to adjust the width of the spreader as an in process adjustment for optimum.