METHOD FOR MANUFACTURING POLYOLEFIN RESIN EXPANDED SHEET

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a polyolefin resin expanded sheet which is almost free from thickness nonuniformity and shows excellent long flatness. SOLUTION: This method for manufacturing a polyolefin resin expanded sheet which shows 1.1 to 5X expansion ratio and superb long flatness comprises the steps to knead/melt a polyolefin resin containing a foaming agent with the help of an extruder, then discharge the melt to an air fluidization bed in the form of a sheet, from an extruder die and jet air to both face/back of a discharge sheet at the air fluidization bed while the sheet is tense and further, expand the interior while cooling a surface layer part. After these steps, the sheet is tightly held between a pair of endless steel belts and cooled/shaped while being conveyed.