Packaging apparatus for forming specially shaped packages

The method of making a package comprising the steps of:

• placing a product in a cup-shaped receptacle made of formable packaging material and having a flange around the mouth thereof establishing sealing surfaces in the plane of said mouth;
• said receptacle having a lateral dimension greater than the width of the product so as to create open regions between the product side surfaces and the receptacle side walls;
• said receptacle having a depth such that the top surface of the product is at least approximately aligned with said flange when the product is first placed in the receptacle;
• placing a sheet of formable packaging material over said mouth and said sealing surfaces to define a container therebetween, said sheet including outer portions located above said open regions;
• establishing a sealed chamber around said container;
• evacuating said container and the spaces within said chamber which are above and below said container;
• sealing said sheet of packaging material to said receptacle to produce an hermetically sealed package;
• and
• controllably venting the spaces of said chamber above and below said container (1) to develop a net differential force causing relative movement of said outer sheet portions towards the product so as to form said sheet portions down along the side surfaces of the product into said open regions to an intermediate point between the bottom and top surfaces of the product, and (2) to press the side walls of said receptacle inwardly to the product side surfaces to effect engagement between said sheet and said receptacle side wall at said intermediate point in the region immediately adjacent the side surface of the product, creating a crowned effect wherein the flange line is at said intermediate point below the top surface of the product.