PURPOSE: To make possible molding without redrying after a long period of preservation by a method wherein polyester pellet immediately after drying is heatsealed by using laminated film composed of resin layers which are arranged on both inner and outer sides of an aluminum layer as the middle layer.
CONSTITUTION: A packing bag made of laminated film (resin capable of heatsealing such as polyethylene is used as the innermost layer) which is provided on both sides of an aluminum layer with a thickness 7W25μm is used. In other words, dry polyester pellets (content of water is 0.02wt% or less) are contained in the above-mentioned packing bag and heatsealed hermetically. As a rule, unhygroscopic resin is used for the innermost layer of the packing bag (the layer capable of heatsealing), but, on the contrary, the resin layer composed of resin with a hygroscopic degree 2% or more (such as polyvinyl alcohol) may be used or dryer may coexist in the packing bag.
ASANO MASAJI
KAWAMOTO MASAO
| JPS5512029A | 1980-01-28 |