To produce a thermoplastic resin foam having constant thickness and reutilize the cut flange thereof.
A foamable thermoplastic resin sheet 1 wherein foamable thermoplastic resin particles 2 containing a foaming agent are almost uniformly arranged in a planar state and integrally connected by a foamable thermoplastic resin membrane 3 is supplied to the gap between a pair of endless conveyor belts 21 and 22 and heated to the decomposition temp. of the foaming agent or higher between the endless conveyor belts 21 and 22 under pressure while fed between those belts 21 and 22 to produce a foam. In this foam producing method, at least the endless conveyor belt 21 on the side of the foamable thermoplastic resin membrane 3 is constituted of a belt having through-holes 21a with a diameter of 0.2-1.2 mm provided thereto at a pitch of 5-50 mm.
SASAYAMA MICHIAKI
NAGARA HIDEFUMI
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