is widely used in kitchen applications to cover bowls of salad etc which are placed in a domestic fridge the purpose of the film 219 is simply to act as a release agent and ensure that the end walls and side walls 203 204 are maintained clean between individual moulding applications in particular the film 219 extends over the hinges 220 so as to maintain same free of liquid cement during the moulding procedure if the polyethylene film 219 is not used commercially available spray on release agents can be used instead on top of the aluminium foil 228 is placed a dimpled or castellated sheet 227 fabricated from moulded or pressed paper or cardboard material such sheets 227 are widely used in the egg industry as one portion of a two portion container for eggs such sheets 227 are inexpensive and provide a convenient means of forming the desired pattern of protrusions and recesses on the interior surface of the panel 205 such sheets 227 are also used for pears apples tomatoes etc and so a number of such sheets each with a different profile and or dimensions are available once the film 219 and egg carton sheet 227 are in place the side walls 203 and 204 are swung up into and latched in a vertical position in which they.