an apparatus for use with xerographic equipment or the like automatically applies a plastic u - shaped spline binder strip from a cassette housing a plurality of strips onto a first edge of a document set clamped to a planar surface . a binding strip cassette storage holds a plurality of binding strips for single - file automatic installation onto a series of document sets generated by the xerographic equipment . a spreader member disposed between the cassette storage and the document set opens finger portions of the binding strip as it translates from the cassette and onto the document set .