Continuous production of plastic siding panels with separate shingle appearance

Apparatus for continuously producing elongated siding panels, said apparatus comprising:

• an endless conveyor;
• a die for extruding a continuous sheet of heated plastics material such that the continuous sheet has a generally uniform thickness and has longitudinal upper and lower portions integrally connected by a longitudinal intermediate portion;
• a continuous series of rigid mold plates supported by said endless conveyor and defining shingle cavities and undercut cavities and having vacuum passages, whereby a vacuum is created within the cavities while the mold plates are moving on said upper run of said endless conveyor for progressively vacuum-forming the sheet into the shingle cavities and the undercut cavities of the mold plates;
• a guide directing the sheet of heated material onto said mold plates;
• and
• a reciprocating and traveling forming plug positioned for successively inserting into said undercut cavities, whereby a series of integrally connected siding panels are formed as the sheet is moving and being vacuum formed into said undercut cavities.