Method and apparatus for manufacturing foamed product

An apparatus for producing a foam-molded product, comprising:

• a plasticizing cylinder which has a plasticization zone for plasticizing and melting a thermoplastic resin into a molten resin and a starvation zone for allowing the molten resin to be in a starved state, and which has an introducing port for introducing a physical foaming agent into the starvation zone;
• an introducing speed adjusting container which is connected to the introducing port;
• and
• a physical foaming agent supply mechanism which is connected to the introducing speed adjusting container and which supplies the physical foaming agent to the plasticizing cylinder via the introducing speed adjusting container,
• wherein the physical foaming agent supply mechanism supplies the physical foaming agent having a fixed pressure into the starving zone of the plasticizing cylinder to maintain pressure in the starvation zone at the fixed pressure constantly during production of the foam-molded product,
• wherein a maximum value of an inner diameter of the introducing speed adjusting container is larger than an inner diameter of the introducing port, and
• wherein the introducing port is always open.

A method for producing a foam-molded product, the method comprising,

• providing a plasticizing cylinder which has a plasticization zone for plasticizing and melting a thermoplastic resin into a molten resin and a starvation zone for allowing the molten resin to be in a starved state, and which has an introducing port for introducing a physical foaming agent into the starvation zone;
• and
• providing an introducing speed adjusting container having:
• a cylindrical straight portion connected to the introducing port;
• and a taper portion which is connected to the straight portion and of which inner diameter is larger with distance from the introducing port,
• plasticizing and melting the thermoplastic resin to provide the molten resin in the plasticization zone;
• supplying a pressurized fluid containing the physical foaming agent having a fixed pressure into the introducing speed adjusting container;
• warming the pressurized fluid containing the physical foaming agent having the fixed pressure in the taper portion;
• introducing the warmed pressurized fluid containing the physical foaming agent having the fixed pressure from the introducing speed adjusting container into the starvation zone via the straight portion to maintain pressure in the starvation zone at the fixed pressure constantly during production of the foam-molded product;
• bringing the molten resin in the starved state in contact with the pressurized fluid in the starvation zone while maintaining the pressure in the starvation zone at the fixed pressure;
• and
• molding the molten resin having been brought in contact with the pressurized fluid containing the physical foaming agent into the foam-molded product,
• wherein the introducing port is always open.