Method and apparatus for folding and sealing a floppy disc envelope

Abstract

A center fold is produced in a floppy disc envelope by partially folding a pre-cut sheet of polyvinyl chloride (PVC) having two spaced center holes. The center holes are forced over a precision pedestal affixed to a flat support surface. A first fold bar is lowered against the partially folded sheet, flattening first and second sections of the sheet on each side of a fold line against the support surface, producing a fold of controlled radius. A heat lamp is utilized to anneal the fold for a predetermined time, after which the fold bar is raised. A flap extending from the first section of the sheet is folded back against the second section of the sheet by means of an apparatus including a flat support, a precision pedestal for aligning and retaining the partially folded envelope, and a second fold bar having a lip for engaging the edge of the flap. The second fold bar moves along an arcuate path controlled by a four bar linkage, folding the flap back against the second section and simultaneously forcing the fold end of the flap against a resilient pad adjacent a rigid stop attached to the support surface, producing a permanent end fold having a controlled radius of curvature. The folded flap is then sealed by means of an apparatus including a clamp bar, a heat lamp, and a movable hot sealing bar. After the envelope is aligned, the clamp bar engages the flap adjacent the end fold and forces the flap against the envelope. The heat lamp is turned on, annealing the fold. The hot sealing bar is forced against the free end of the flap, welding the end of the flap to the envelope.