Abstract: There is disclosed an improved form of folding arms in a tray packaging wrapping machine that elevates a tray of meat or other product causing it to be wrapped on top and sides by a sheet of stretchable PVC film after which arms fold the edges of the film underneath the tray; wherein the improved folding arms move with nonrotational motion from opposing edges of the tray toward the center of the tray. Said arms have a film-engaging edge portion with a length substantially less than the width of the film sheet being folded, this edge portion being defined by an indentation in the outline of the arm at each end of the edge portion; the depth of the indentations are about 10% to about 50% of the length of the film-engaging edge portion and the transition between the film-engaging edge portion and the indentations is curved with a radius of curvature of about one-half inch.