Thin low-magnification foam sheet molding method and molding sizing block

摘要

PROBLEM TO BE SOLVED: To provide both a molding method for a foamed sheet, in which an unfoamed layer having a smooth surface is provided and thickness is =2 mm and expansion ratio is 1.4-3.0 times, and a sizing block therefor. SOLUTION: Both surfaces of a sheetlike material 2 extruded from a T-die 1 are sucked and brought into contact with the surfaces of a first and second sizing block bodies 4a, 4b oppositely arranged so as to sandwich the sheetlike material 2 from both sides via a plurality of finely narrow grooves 7a, 7b formed in both sizing block bodies 4a, 4b and vacuum suction longitudinal holes 8a, 8b communicating with these finely narrow grooves in the slightly separated position on the downstream side of the T-die 1. Also, while the sheetlike material 2 is passed, both surfaces thereof are cooled and solidified by a cooling medium circulated through a plurality of flow paths 5a, 5b, 6a, 6b of the cooling medium. Thereby, such the foamed sheet 3 is molded that a smooth skin layer of an unformed state is provided and thickness is =2 mm and expansion ratio is 1.4-3.0 times.