utilized in the bag assembly.The construction of the bag assembly 11 can be similar to that described in U.S. Pat. No. 5,446,938.Bags 12 and 13 are preferably formed of fabric, such as nylon or polyester, impregnated with a thermoplastic resin and have contiguous horizontal surfaces which are joined together along an annular sealed area 14 that borders an unsealed centralarea.