METHOD FOR ADDING SUPERCRITICAL CARBON DIOXIDE AND PRODUCING PROCESS FOR EXPANDING THERMOPLASTIC RESIN PRODUCT THEREOF

摘要

The present invention provides a method of a molding machine at a constant discharge speed stable addition of a predetermined amount of supercritical carbon dioxide and, using this method of addition it provides a method for producing a thermoplastic resin foam. More specifically, the injection of carbon dioxide to the dispense pumps in while maintaining the liquid state, the liquefied carbon dioxide cylinder (1), and when step-up to the discharge by the carbon dioxide to the dispense pump (2), the critical pressure of carbon dioxide ( 7.4MPa) in controlling the discharge pressure of the carbon dioxide to any pressure in the range of up to 40MPa, by setting the pressure of the pressure control valve (3) to discharge carbon dioxide without a variation in the discharge amount and discharging the carbon dioxide, the carbon dioxide, the carbon dioxide after the critical temperature of the heated above (31 ℃), it converted into a supercritical carbon dioxide, characterized in that addition of the supercritical carbon dioxide to a molten thermoplastic resin in the molding machine (4).