EP0672512A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Preplasticizing type injection apparatus
Assignee: Nissei Plastic Industrial Co Ltd
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Filing: 1995-03-16
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Granted: —
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Expires: 2015-03-16
Abstract
Abstract A preplasticizing type injection apparatus comprising an injection cylinder (12) internally provided with an injection plunger (10) and a plasticizing cylinder (22) provided in the inside with a plasticizing screw (20) or plunger, said injection and plasticizing cylinders (12,22) being arranged in juxtaposition and held in communication with each other by way of a resin conduit (3) connecting an inlet path (15) of the injection cylinder (12) arranged at the front end thereof and defining the limit of advancement of the plunger (10) and an outlet path (21) of the plasticizing cylinder (22) arranged at the front end thereof so that a front end portion of the injection cylinder (12) is charged with resin molten in the plasticizing cylinder (22) and the resin in the front end portion of the injection cylinder (12) is injected into a mold by means of the plunger (10), characterized in that the resin conduit (3) is realized in the form of a small metal pipe having an inner diameter between 5 and 10 mm and a length at least five times and preferably twenty to forty times greater than the inner diameter of the pipe and provided on the outer periphery with temperature control means (31) is provided. With such a conduit (3), resin passing therethrough can be more kneaded to improve the distribution of heat and plasticity before it gets to the injection cylinder (12).
Inventors
- 👤 Kiyoto Takizawa
- 👤 Hisato Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 04:36
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/46; B29C45/53; B29C45/54
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
185 words
A preplasticizing type injection apparatus comprising an injection cylinder internally provided with an injection plunger and a plasticizing cylinder provided in the inside with a plasticizing screw or plunger, said injection and plasticizing cylinders being arranged in juxtaposition and held in communication with each other by way of a resin conduit connecting an inlet path of the injection cylinder arranged at the front end thereof and defining the limit of advancement of the plunger and an outlet path of the plasticizing cylinder arranged at the front end thereof so that a front end portion of the injection cylinder is charged with resin molten in the plasticizing cylinder and the resin in the front end portion of the injection cylinder is injected into a mold by means of the plunger, characterized in that the resin conduit is realized in the form of a small metal pipe having an inner diameter between 5 and 10 mm and a length at least five times and preferably twenty to forty times greater than the inner diameter of the pipe and provided on the outer periphery with temperature control means.
Claim 2
Dependent Claim
44 words
A preplasticizing type injection apparatus according to claim 1, wherein said temperature control means is a band heater or a composite device comprising a coolant jacket and a band heater arranged on the outer periphery of the coolant jacket to form a multi-layer structure.
Claim 3
Dependent Claim
28 words
A preplasticizing type injection apparatus according to claim 1 or 2, wherein said resin conduit is provided in an upper portion thereof with at least a mixing device.
Claim 4
Dependent Claim
244 words
A preplasticizing type injection apparatus comprising an injection cylinder internally provided with an injection plunger and a plasticizing cylinder provided in the inside with a plasticizing screw or plunger, said injection and plasticizing cylinders being arranged in juxtaposition and held in communication with each other by way of a resin conduit connecting an inlet path of the injection cylinder arranged at the front end thereof and defining the limit of advancement of the plunger and an outlet path of the plasticizing cylinder arranged at the front end thereof so that a front end portion of the injection cylinder is charged with molten resin in the plasticizing cylinder and the resin in the front end portion of the injection cylinder is injected into a mold by means of the plunger, characterized in that it further comprises a check valve arranged at the front end of the plasticizing cylinder and realized in the form of a mushroom having a substantially conical head and an inclined rear side, a front end portion of the plasticizing cylinder being provided with a recess having a profile corresponding to that of the conical head of the check valve for receiving the check valve with a gap arranged between the valve and the wall of the recess to secure a resin flow path held in communication with the resin conduit of the apparatus, and an annular valve seat disposed vis-a-vis the inclined rear side of the check valve in the cylinder.
Claim 5
Dependent Claim
54 words
A preplasticizing type injection apparatus according to claim 4, wherein said check valve is so designed as to retreat with the screw immediately after the plasticizing cylinder stops operating and abut the valve seat at the inclined rear side thereof to block the resin flow path constituted by the clearance around the check valve.
Claim 6
Dependent Claim
38 words
A preplasticizing type injection apparatus according to claim 4, wherein said check valve is so designed as to retreat for closure with the screw after the plasticizing cylinder stops operating, while monitoring the position of the injection plunger.
Claim 7
Dependent Claim
149 words
A preplasticizing type injection apparatus comprising an injection cylinder internally provided with an injection plunger and a plasticizing cylinder provided in the inside with a plasticizing screw or plunger, said injection and plasticizing cylinders being arranged in juxtaposition and held in communication with each other by way of a resin conduit connecting an inlet path of the injection cylinder arranged at the front end thereof and defining the limit of advancement of the plunger and an outlet path of the plasticizing cylinder arranged at the front end thereof so that a front end portion of the injection cylinder is charged with molten resin in the plasticizing cylinder and the resin in the front end portion of the injection cylinder is injected into a mold by means of the plunger, characterized in that the inlet path is inclined before it gets to the inner peripheral surface of the injection cylinder.
Claim 8
Dependent Claim
183 words
A preplasticizing type injection apparatus comprising an injection cylinder internally provided with an injection plunger and a plasticizing cylinder provided in the inside with a plasticizing screw or plunger, said injection and plasticizing cylinders being arranged in juxtaposition and held in communication with each other by way of a resin conduit connecting an inlet path of the injection cylinder arranged at the front end thereof and defining the limit of advancement of the plunger and an outlet path of the plasticizing cylinder arranged at the front end thereof so that a front end portion of the injection cylinder is charged with molten resin in the plasticizing cylinder and the resin in the front end portion of the injection cylinder is injected into a mold by means of the plunger, characterized in that the injection cylinder is provided with a bore through the wall of the cylinder for drawing out resin caught in the clearance between the cylinder and the plunger at a position behind the stroke of the plunger and also with a band heater having an effective heating zone covering the bore.
References Cited (Backward Citations)
No citation records indexed.
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