BULK DENSITY MEASURING EQUIPMENT AND MEASURING METHOD OF PREFOAMED PARTICLE, AND METHOD FOR PRODUCING PREFOAMED PARTICLE

摘要

Equipment and a method for measuring in a short time the bulk density of prefoamed particles foamed in a prefoaming equipment and wetted with water, and a method for producing prefoamed particles having a uniform bulk density and a stabilized expansion ratio by regulating the foaming conditions during the foaming time in the prefoaming equipment based on the measurements of bulk density taken by the equipment and method. A part of prefoamed particles of foaming thermoplastic resin being fed from a prefoaming equipment (10) to a prefoamed particle storage tank (30) is sampled through sampling piping (9) into a sample container (12). It is then dried with air flow by being discharged from the sample container (12) to a dryer (15) by means of a fan. Bulk density of dried prefoamed particles is then measured automatically by a bulk density measuring apparatus (16). The measurements are compared with a target value by a bulk density comparing/operating unit (17) and fed back to the prefoaming equipment (10) in order to regulate the foaming conditions of prefoamed particles.