MOLDING MATERIAL FOR EXTRUSION FOAM MOLDING, PROCESS FOR PRODUCING SAME, WOODY MOLDED FOAM PRODUCED FROM THE MOLDING MATERIAL, AND PROCESS AND APPARATUS FOR PRODUCING THE WOODY MOLDED FOAM

摘要

DISCLOSED IS A MOLDING MATERIAL (25A) FOR EXTRUSION FOAM MOLDING FROM WHICH WOODY MOLDED FOAM OF HIGH QUALITY CAN BE OBTAINED. FROM THE MOLDING MATERIAL, WOODY MOLDED FOAM OF HIGH QUALITY WITH NO DEFECTS IS EFFICIENTLY PRODUCED. CONSTITUENT MATERIALS COMPRISING WOODMEAL AND A THERMOPLASTIC RESIN AS MAJOR COMPONENTS AND CONTAINING 1-5 WT% ALKANE HAVING A MOLECULAR WEIGHT OF 300-1,000 G/MOL ARE MELT-KNEADED UNTIL THE COMPONENTS COME INTO AN EVENLY DISPERSED STATE, AND THE RESULTANT MIXTURE IS MOLDED INTO PELLETS HAVING A GIVEN DIAMETER TO OBTAIN A MOLDING MATERIAL. SUBSEQUENTLY, THIS MOLDING MATERIAL IS EXTRUSION-MOLDED INTO A GIVEN SHAPE TOGETHER WITH A BLOWING AGENT BY MEANS OF AN EXTRUSION MOLDING DEVICE, THEREBY OBTAINING WOODY MOLDED FOAM. THE EXTRUSION MOLDING IS PREFERABLY CONDUCTED IN A MANNER SUCH THAT THE EXTRUDATE EXTRUDED FROM THE EXTRUDER (12) IS INTRODUCED INTO THE MOLDING CHAMBER (31) OF A MOLDING DIE (30) WHILE KEEPING THE EXTRUDATE IN THE PRESSURIZED STATE AND THE EXTRUDATE IS RELEASED FROM THE PRESSURE UPON INTRODUCTION INTO THE MOLDING CHAMBER OF THE MOLDING DIE TO FOAM THE EXTRUDATE.