Abstract: In an apparatus for preparing absorbent pad lined packaging trays, means sense the tail end of a liner supply that is to be discarded, determines and cuts off the length thereof, withdraws the cut off length from the line of machine operation and feeds into such line the lead position of a fresh liner supply. Other means denest a supply of flanged trays to be pad lined by at least two denesters that comprise synchronized, vertically oriented rotary bodies that during parts of a single rotation each have a bottom laterally extending plate that supports the bottom-most tray of a stack, an upper laterally extending plate that supports at tray flanges the next in line tray to be denested an a laterally extending, vertically inclined cam plate that is adapted to ride on the upper flange surface of a tray that is in the process of being denested to thereby forcibly eject same.