Method for deep drawing sheet metal

Abstract From the Canadian patent

An improved method of lubrication in a deep drawing process utilizes a plurality of distinct plastic sheets loosely overlying one another, laid across at least one major surface of a flat blank to be drawn. In preferred practice, a pair of such distinct plastic sheets are laid across each of the opposed major surfaces of a flat blank in preparation for a drawing operation. The plastic sheets are maintained in position while interfitting drawing tools namely a punch and a die, close together to effect drawing of the blank. The plastic sheets serve as a lubricant during the drawing process. Selected surfaces of the sheets or the material from which the sheets are formed may be provided with …