Hot melt extrusion apparatus

Claim 1

Apparatus for coating the underside of a web advancing at a predetermined rate along a generally horizontal path, said apparatus comprising: a press roll mounted at each opposite end in fixed bearings to extend transversely of said web above said path for guiding and supporting said web in an unchanging said path during splicing thereof; coating head means, mounted at each opposite end in support pivots, to extend transversely of said web under said path, for forming a coating nip therewith, said means including actuating mechanism for independently pivoting one said end relative to the other to skew said head relative to said roll to control coating thickness, said coating head having an elongated lead-on lip and an elongated, rounded, lead-off lip removably mounted thereon and jointly defining a narrow extrusion slot connecting with a central feed plenum chamber, said slit and chamber being free of obstructions and free of gap adjustment screws in the path of extrudate emerging from said slit; said lead-off lip being flexible and distortable along its length and said head including a plurality of spaced threaded screws therealong forming means to push and pull said lead-off lip to vary the width of said slit and control the thickness of coating extruded therefrom.