Apparatus for forming polymer, comprising polymer backflow prevention portion

Patent metadata

Field	Value
Publication number	US-10201920-B2
Application number	US-201314650392-A
Country	US
Kind code	B2
Filing date	Dec 12, 2013
Priority date	Dec 12, 2012
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

The present invention provides an apparatus for forming a polymer, comprising: a chamber having a predetermined pressure and storing a molten polymer resin; a foaming agent injection portion connected to the chamber and supplying a foaming agent, which is supplied from the outside, into the chamber by forming a pressure equal to or higher than the pressure inside the chamber; and a polymer backflow prevention portion provided at the foaming agent injection portion, and through which the supplied foaming agent passes so as to increase a contact surface area with the polymer resin, thereby preventing the backflow of the polymer resin.

First claim

The invention claimed is:

1. A polymer forming apparatus comprising:
a chamber having a predetermined pressure and storing a molten polymer resin;
a foaming agent injector connected to the chamber and supplying a foaming agent received from outside into the chamber by a pressure higher than or equal to a pressure inside the chamber, wherein the foaming agent injector comprises:
a foaming agent injection pipe, wherein the foaming agent injection pipe comprises:
an inlet channel forming an inlet for the foaming agent;
an outlet channel forming an outlet for the foaming agent; and
a middle channel connecting the inlet channel to the outlet channel and having a smaller inner diameter than the inlet channel and the outlet channel,
wherein the inlet channel is connected to an upper end of the middle channel, and the inlet channel has an inlet-side inclined channel having an inner diameter gradually decreasing toward the upper end of the middle channel,
wherein the outlet channel is connected to a lower end of the middle channel, and the outlet channel has an outlet-side inclined channel having an inner diameter gradually increasing downward from the lower end of the middle channel, and
wherein the inlet-side inclined channel and the outlet-side inclined channel are symmetrical to each other with respect to the middle channel;

an elastic shut-off unit elastically disposed inside the outlet channel to be placed at an outlet side of the middle channel, and configured to open or close the middle channel according to pressure of supplying the foaming agent, wherein the elastic shut-off unit comprises:
a shut-off ball in the outlet-side inclined channel, wherein the shut-off ball is configured to open or close the outlet-side inclined channel; and
an elastic member between the shut-off ball and a polymer backflow prevention unit, wherein the elastic member is configured to elastically support the shut-off ball;

the polymer backflow prevention unit provided to the foaming agent injector and allowing the supplied foaming agent to pass therethrough while preventing the polymer resin from flowing back by increasing a contact surface area with the polymer resin, wherein the polymer backflow prevention unit is disposed at an end of the outlet channel and supports the elastic shut-off unit, and wherein the polymer backflow prevention unit comprises:
a backflow-prevention plate body disposed at the end of the outlet channel and supporting an end of an elastic member, wherein the backflow-prevention plate body is detachably coupled to the end of the outlet channel; and
a plurality of backflow prevention holes formed in the backflow-prevention plate body,
wherein the backflow preventing holes are spaced apart from each other, and a cross-sectional shape of each of the backflow prevention holes is a cross shape, each of the backflow prevention holes is tapered in a direction of supplying the foaming agent, and each of the backflow prevention holes has a plurality of protrusions on an inner circumference thereof,
wherein the plurality of protrusions comprises hemispherical protrusions or polygonal protrusions,
wherein the plurality of protrusions are continuous from an upper end to a lower end of the backflow prevention hole,
wherein the plurality of protrusions are formed to gradually increase in size along the chamber,
wherein an inner diameter of the backflow prevention holes are formed to gradually decrease along the inside the chamber,
wherein the backflow-prevention plate body is in a disk shape and detachably coupled to the lower end of the outlet channel, and
wherein a circumference of the backflow-prevention plate body and an inner wall of the lower end of the outlet channel are screwed to each other;

a first pressure sensor configured to sense a pressure generated during supply of the foaming gas;
a second pressure sensor configured to sense an internal pressure of the chamber; and
a foaming agent supply unit, wherein the foaming agent supply unit comprises:
a foaming agent supply line connected to the foaming agent injector, configured to supply the foaming agent to the foaming agent injector;
a valve configured to open and the close the foaming agent supply line; and
a controller electrically connected to the first pressure sensor and the second pressure sensor, wherein the controller is configured to supply the foaming gas when the pressure of the foaming agent is higher than the internal pressure of the chamber, and is configured to stop the supply of the foaming agent when the pressure of the foaming agent is lower than the internal pressure of the chamber,
wherein the foaming agent is an incompressible fluid.

2. The polymer forming apparatus according to claim 1 , wherein the backflow prevention plate body is inclined from an edge toward a center in the direction of supplying the foaming agent.

Assignees

• Lg Hausys Ltd

Inventors

• Jeon Byung Joo
• Lee Eung Kee
• Choi Chul June
• Kim Myeong Hee
• Kim Ji Mun
• Ji Seung Wook

Classifications

• B29C45/1816

  Feeding auxiliary material, e.g. colouring material · CPC title

• B29C44/3446 Primary

  Feeding the blowing agent · CPC title

• B29C2945/76775

  Fluids · CPC title

• B29C2945/76006

  Pressure · CPC title

• B29C45/76

  Measuring, controlling or regulating {(measuring in general G01; controlling or regulating in general G05)} · CPC title