CN109291400B - Expandable extrusion die - Google Patents
Expandable extrusion die Download PDFInfo
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- CN109291400B CN109291400B CN201811155475.2A CN201811155475A CN109291400B CN 109291400 B CN109291400 B CN 109291400B CN 201811155475 A CN201811155475 A CN 201811155475A CN 109291400 B CN109291400 B CN 109291400B
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- 238000001125 extrusion Methods 0.000 title claims abstract description 32
- 239000000463 material Substances 0.000 claims abstract description 36
- 238000009825 accumulation Methods 0.000 claims abstract description 6
- 230000037303 wrinkles Effects 0.000 claims description 10
- 229910000831 Steel Inorganic materials 0.000 claims description 8
- 239000010959 steel Substances 0.000 claims description 8
- 239000002861 polymer material Substances 0.000 abstract description 4
- 230000008676 import Effects 0.000 description 6
- 230000003139 buffering effect Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 230000001154 acute effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001330002 Bambuseae Species 0.000 description 1
- 241000251730 Chondrichthyes Species 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
Landscapes
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
The invention relates to the field of polymer material forming processing, in particular to an expandable extrusion die, wherein the inner wall of the die is designed into an elastic inner wall, when materials expand, the inner wall surface can be timely expanded, a molecular chain can be loosened, the accumulation of energy of the material molecular chain on the inner wall of the die is greatly reduced, the flow instability is also greatly reduced, the screw rotating speed is conveniently improved, the extrusion quality and yield are increased, and the manpower, material resources and financial resources are also saved.
Description
Technical Field
The invention relates to the field of polymer material molding processing, in particular to an expandable extrusion die.
Background
Conventional extrusion dies are generally rigid and have difficult to vary inside wall diameters. The defects of the traditional extrusion molding die are as follows: there is an inlet pressure loss at the inlet, producing an inlet effect. The outlet also has pressure loss, and extrusion swelling phenomenon is generated. Because extrusion instability is generally due to excessive energy build-up of the material in the extrusion die and difficulty in timely release, various imperfections in the interior and appearance of the extruded material, such as surface shark skin, bamboo joint defects, stick-slip transitions, and even extrusion breaks, are created.
Disclosure of Invention
The invention aims to solve the technical problems that: in order to solve the technical problems, the invention provides an expandable extrusion die, which mainly considers the pressure loss of an inlet and an outlet, corrects the structure of the extrusion die, greatly reduces the pressure loss of the inlet, simultaneously considers the pressure loss of the outlet, makes the molecular chain of a material relax in time, reduces the accumulation of redundant energy, makes extrusion molding defects less and has higher molding efficiency.
The technical scheme adopted for solving the technical problems is as follows: the utility model provides an expandable extrusion die, includes the inner tube and the outer tube of coaxial setting, the inner wall of inner tube is divided into entry section, advection section and exit section from the import to exit direction in proper order, and the entry angle alpha of entry section and the exit angle beta of exit section are the outside flaring section of acute angle, and entry section length is h1, and advection section length is h2, and exit section length is h3, and h1 is 1/3h2, and h3 is 1/5h2-1/4h2, the both ends of outer tube respectively with the import and the export fixed connection of inner tube. The flaring of the inlet section is to provide a flow transition for material entering the inlet section from the extruder inlet die to reduce inlet pressure loss. After buffering in the inlet section h1, the material flows in the advection section h2, then passes through the outlet section h3 and flows out of the die. The outer tube not only can protect the shape of the inner tube, but also can preserve heat, ensures the melting state of the material, and is favorable for material extrusion.
The entrance angle alpha and the exit angle beta are 30 deg.. The outlet angle of the outlet section is designed to be 30 degrees, which is favorable for the relaxation of material molecular chains.
Considering that the high polymer material generally has the phenomenon of die-release expansion, also called extrusion expansion, the expansion ratio is generally between 1 and 3. In order to enable the materials to relax in the die, the inner tube is an elastic inner tube, the inner tube is formed by encircling thin-wall steel sheets with longitudinal wrinkles, and the longitudinal wrinkles of the inlet section and the outlet section are flatter towards the end part. Because the inlet section and the outlet section are flared, the longitudinal folds of the inlet section and the outlet section are gradually gentle towards the end parts, and the expansion of materials is not affected. The radial cross section of the inner pipe at the advection section is circular with saw-tooth-shaped periphery, in order to ensure that the elastic saw teeth of the inner pipe are denser, the inner wall surface can be timely expanded when materials expand, the molecular chains can be loosened, the accumulation of energy of the material molecular chains on the inner wall of the die is greatly reduced, the flow instability is also greatly reduced, the screw rotating speed is conveniently improved, the extrusion quality and yield are increased, and the manpower, material resources and financial resources are also saved.
Because the advection section can take place slight expansion at the diameter of the both ends of advection section in the inflation in-process, consequently entry section and export section have to both ends tiny motion, for the buffer space of entry section and export section, the both ends inner circle of outer tube has circumferential import retaining ring and export retaining ring, import retaining ring and export retaining ring are thin wall steel sheet, and be provided with annular pincher trees on import retaining ring and the export retaining ring, the port of entry section is connected with the inner circle of import retaining ring, the port of export section is connected with the inner circle of export retaining ring.
The expandable extrusion die has the beneficial effects that the inner wall of the die is designed to be an elastic inner wall, when materials expand, the inner wall surface can be timely expanded, molecular chains can be loosened, the accumulation of energy of the material molecular chains on the inner wall of the die is greatly reduced, the flow instability is also greatly reduced, the screw rotating speed is conveniently increased, the extrusion quality and yield are increased, and the manpower, material resources and financial resources are also saved.
Drawings
The invention will be further described with reference to the drawings and examples.
FIG. 1 is a schematic view showing the structure of a preferred embodiment of an expandable extrusion die of the present invention.
FIG. 2 is a top view of a preferred embodiment of the expandable extrusion die of the present invention.
In the figure: 1. the device comprises an inner pipe, 11, an inlet section, 12, a advection section, 13, an outlet section, 2, an outer pipe, 21, an inlet check ring, 22 and an outlet check ring.
Detailed Description
The invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic representations which merely illustrate the basic structure of the invention and therefore show only the structures which are relevant to the invention.
As shown in fig. 1 and 2, which are the preferred embodiments of the present invention, an expandable extrusion die comprises an inner tube 1 and an outer tube 2 coaxially arranged, wherein the inner wall of the inner tube 1 is divided into an inlet section 11, a advection section 12 and an outlet section 13 in sequence from an inlet direction to an outlet direction, the inlet angle α of the inlet section 11 and the outlet angle β of the outlet section 13 are both acute outward flaring sections, and the inlet angle α and the outlet angle β are both 30 °. The length of the inlet section 11 is h1, the length of the advection section 12 is h2, the length of the outlet section 13 is h3, h1 is 1/3h2, h3 is 1/5h2-1/4h2, if the length of the advection section h2=15 mm, h1=5 mm, h3=3 mm. The two ends of the outer tube 2 are respectively connected with the inlet and the outlet of the inner tube 1, and the outer part of the outer tube 2 is cylindrical.
The inner tube 1 is an elastic inner tube, the inner tube 1 is formed by encircling thin-wall steel sheets with longitudinal folds, and the longitudinal folds of the inlet section 11 and the outlet section 13 are flatter towards the end parts. The inner rings at the two ends of the outer tube 2 are provided with circumferential inlet check rings 21 and outlet check rings 22, the inlet check rings 21 and the outlet check rings 22 are all thin-wall steel sheets, annular wrinkles are fully distributed on the inlet check rings 21 and the outlet check rings 22, the ports of the inlet sections 11 are connected with the inner rings of the inlet check rings 21, and the ports of the outlet sections 13 are connected with the inner rings of the outlet check rings 22.
The flaring of the inlet section 11 is designed to provide a flow transition to the material from the extruder inlet die inlet section to reduce inlet pressure losses. The same is considered for the outlet section 13. But because the inlet section 11 has a larger pressure loss, the inlet section 11 has a longer length. After buffering in the inlet section 11, the material flows in the advection section 12, and then through the outlet section 13, and out of the die. The outlet angle of the outlet section 13 is designed to be 30 degrees, which is also beneficial to the relaxation of material molecular chains.
Considering that the high polymer material generally has the phenomenon of die-release expansion, also called extrusion expansion, the expansion ratio is between 1 and 3, generally about 2.2, and more than 1 point is lower. In order to enable the materials to relax in the die, the inner tube 1 is an elastic inner tube, the inner tube 1 is formed by encircling thin-wall steel sheets with longitudinal wrinkles, and the inner tube is similar to a spring piece and has elasticity for restoring the original shape, and the longitudinal wrinkles of the inlet section 11 and the outlet section 13 are gradually gentle towards the end parts. As shown in the figure, the inlet check ring 21 connected with the inlet section 11 and the outer tube 2 is provided with a plurality of annular wrinkles in the top view of the die, so that the space for buffering the inlet section 11 is also provided with the outlet section 13, and the inner wall surface of the inner tube 1 is also provided with longitudinal dense elastic wrinkles, so that the inner wall surface can be timely expanded when materials expand, molecular chains are loosened, the accumulation of energy of the material molecular chains on the inner wall of the die is greatly reduced, the flow instability is also greatly reduced, the screw rotating speed is conveniently improved, the extrusion quality and yield are increased, and the manpower, material resources and financial resources are also saved. The spring force of the spring piece is enough to ensure that the spring piece cannot be damaged by the transitional extrusion of the expanded material. The elastic force of the spring piece is balanced with the expansion extrusion force of the material, so that the enough relaxation of the molecular chain of the material can be ensured, the stress concentration is reduced, and the material can be extruded to a certain extent, so that the surface of the material is compact. The spring piece can also be loaded with a pressure sensor to control the protection spring piece. The longitudinal spring pieces are always in seamless contact with each other to form longitudinal wrinkles, so that no flaws are generated on the surface of the material.
With the above-described preferred embodiments according to the present invention as an illustration, the above-described descriptions can be used by persons skilled in the relevant art to make various changes and modifications without departing from the scope of the technical idea of the present invention. The technical scope of the present invention is not limited to the description, but must be determined according to the scope of claims.
Claims (2)
1. An expandable extrusion die, characterized by: the inner wall of the inner pipe (1) is sequentially divided into an inlet section (11), a advection section (12) and an outlet section (13) from an inlet to an outlet, the inlet angle alpha of the inlet section (11) and the outlet angle beta of the outlet section (13) are both acute-angled outward flaring sections, the length of the inlet section (11) is h1, the length of the advection section (12) is h2, the length of the outlet section (13) is h3, h1 is 1/3h2, h3 is 1/5h2-1/4h2, and two ends of the outer pipe (2) are respectively connected with the inlet and the outlet of the inner pipe (1);
the inner tube (1) is an elastic inner tube, the inner tube (1) is formed by encircling thin-wall steel sheets with longitudinal folds, and the longitudinal folds of the inlet section (11) and the outlet section (13) are flatter towards the end part; the thin-wall steel sheet is a spring piece, has elasticity for recovering the original shape, the elasticity of the spring piece is balanced with the expansion extrusion force of the material, and a pressure sensor is loaded on the spring piece; the longitudinal spring pieces are always in seamless contact with each other to form longitudinal wrinkles, so that no flaws are generated on the surface of the material;
the two ends of the outer tube (2) are provided with circumferential inlet check rings (21) and outlet check rings (22), the inlet check rings (21) and the outlet check rings (22) are all thin-wall steel sheets, annular wrinkles are arranged on the inlet check rings (21) and the outlet check rings (22), the ports of the inlet section (11) are connected with the inner rings of the inlet check rings (21), and the ports of the outlet section (13) are connected with the inner rings of the outlet check rings (22);
when the material expands, the inner wall surface of the elastic inner tube expands, the molecular chain can relax, the accumulation of energy of the material molecular chain on the inner wall of the die is reduced, the flow instability is reduced, the rotating speed of the screw is conveniently improved, and the extrusion quality and the extrusion yield are increased.
2. An expandable extrusion die according to claim 1 wherein: the inlet angle alpha and the outlet angle beta are both 30 degrees.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811155475.2A CN109291400B (en) | 2018-09-30 | 2018-09-30 | Expandable extrusion die |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811155475.2A CN109291400B (en) | 2018-09-30 | 2018-09-30 | Expandable extrusion die |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109291400A CN109291400A (en) | 2019-02-01 |
| CN109291400B true CN109291400B (en) | 2023-11-14 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811155475.2A Active CN109291400B (en) | 2018-09-30 | 2018-09-30 | Expandable extrusion die |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109291400B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0093894A1 (en) * | 1982-05-06 | 1983-11-16 | Hüls Troisdorf Aktiengesellschaft | Extruder tool |
| CN201006632Y (en) * | 2006-09-29 | 2008-01-16 | 广东省广州番禺电缆厂有限公司 | Mold core and mold sleeve of electric cable production squeezing type matching mold |
| CN103009601A (en) * | 2012-12-17 | 2013-04-03 | 常州大学 | Extrusion molding die capable of improving extrusion yield and surface quality |
| CN106827446A (en) * | 2017-01-14 | 2017-06-13 | 常州大学 | The corrugated extrusion neck ring mold of gradual change type |
| CN207808429U (en) * | 2018-01-31 | 2018-09-04 | 浙江科普特新材料有限公司 | A kind of detachable extrusion neck ring mold |
| CN108481703A (en) * | 2018-04-04 | 2018-09-04 | 何盼 | A kind of flat hole extrusion neck ring mold of Masterbatch |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7001165B2 (en) * | 2003-05-02 | 2006-02-21 | Certainteed Corporation | Sizer for forming shaped polymeric articles and method of sizing polymeric articles |
-
2018
- 2018-09-30 CN CN201811155475.2A patent/CN109291400B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0093894A1 (en) * | 1982-05-06 | 1983-11-16 | Hüls Troisdorf Aktiengesellschaft | Extruder tool |
| CN201006632Y (en) * | 2006-09-29 | 2008-01-16 | 广东省广州番禺电缆厂有限公司 | Mold core and mold sleeve of electric cable production squeezing type matching mold |
| CN103009601A (en) * | 2012-12-17 | 2013-04-03 | 常州大学 | Extrusion molding die capable of improving extrusion yield and surface quality |
| CN106827446A (en) * | 2017-01-14 | 2017-06-13 | 常州大学 | The corrugated extrusion neck ring mold of gradual change type |
| CN207808429U (en) * | 2018-01-31 | 2018-09-04 | 浙江科普特新材料有限公司 | A kind of detachable extrusion neck ring mold |
| CN108481703A (en) * | 2018-04-04 | 2018-09-04 | 何盼 | A kind of flat hole extrusion neck ring mold of Masterbatch |
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| Publication number | Publication date |
|---|---|
| CN109291400A (en) | 2019-02-01 |
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