METHOD FOR MANUFACTURING THERMOPLASTIC RESIN FOAM

摘要

PROBLEM TO BE SOLVED: To provide a means enabling improvement simply in an early stage in order to efficiently perform the finding out of a stable extrusion condition or the return to a stable state in the searcing of an extrusion condition or the generation of fluctuations in an extrusion state during the production of foam. SOLUTION: When it is observed that the dissolution of a foaming agent is insufficient through an observation window for observing the interior of the resin flow channel of an extruder, the pressure in the system of the extruder is raised by the pressure regulator provided in the extruder to accelerate the dissolution of the foaming agent. By this constitution, a condition for stably obtaining good foam can be set.