초록 ▼

This invention provides a method for stably adding a predetermined amount of supercritical carbon dioxide at a fixed delivery rate into a forming machine and also a process for producing an expanded thermoplastic resin product by making use of the addition method. Carbon dioxide is charged from a li

This invention provides a method for stably adding a predetermined amount of supercritical carbon dioxide at a fixed delivery rate into a forming machine and also a process for producing an expanded thermoplastic resin product by making use of the addition method. Carbon dioxide is charged from a liquefied carbon dioxide cylinder (1) into a predetermined amount deliverable pump (2) while allowing the carbon dioxide to remain in a liquefied state. When the carbon dioxide is pressurized and delivered by the predetermined amount deliverable pump (2), a delivery pressure of the carbon dioxide is controlled at an optional pressure within a range of from a critical pressure (7.4 MPa) of carbon dioxide to 40 MPa to deliver the carbon dioxide without any fluctuation of the amount of the delivery by setting up the pressure of a pressure control valve (3). The carbon dioxide is heated to a critical temperature (31.degree. C.) of carbon dioxide or higher to convert it into supercritical carbon dioxide. This supercritical carbon dioxide is then added to a molten thermoplastic resin in the forming machine (4).

대표청구항 ▼

[ What is claimed is:] [1.]1. A method for the addition of supercritical carbon dioxide to a molten thermoplastic resin, which comprises charging carbon dioxide from a liquefied carbon dioxide cylinder (1) into a predetermined amount deliverable pump (2) while allowing said carbon dioxide to remain

[ What is claimed is:] [1.]1. A method for the addition of supercritical carbon dioxide to a molten thermoplastic resin, which comprises charging carbon dioxide from a liquefied carbon dioxide cylinder (1) into a predetermined amount deliverable pump (2) while allowing said carbon dioxide to remain in a liquefied state, delivering said carbon dioxide from said predetermined amount deliverable pump (2) in such a manner that, when said carbon dioxide is pressurized and delivered by said predetermined amount deliverable pump (2), a delivery pressure is controlled at an optional pressure in a range of from a critical pressure (7.4 MPa) of carbon dioxide to 40 MPa to deliver said carbon dioxide without any fluctuation of the amount of the delivery by setting up the pressure of a pressure control valve (3), heating said carbon dioxide to a critical temperature (31.degree. C.) of carbon dioxide or higher to convert said carbon dioxide into supercritical carbon dioxide, and then adding said supercritical carbon dioxide to said molten thermoplastic resin into a forming machine.