An extrusion die with a deflection diverter hole for a plastic extruder

Abstract

The invention discloses an extrusion die with a deflected diverter hole for a plastic extruder, comprising a core die assembly extending in the front-to-back direction; a diverter assembly comprising a diverter cone and a diverter ring, wherein the diverter cone, the diverter ring and the core die assembly are coaxially fixedly connected in sequence from front to back; a mouth die assembly, which is coaxially fixedly sleeved on the outside of the core die assembly and the diverter assembly, the mouth die assembly having a material inlet and a diverter flow channel between the mouth die assembly and the diverter cone, an extrusion flow channel between the mouth die assembly and the core die assembly, the diverter ring having a plurality of diverter holes passing through the diverter ring, the material inlet, the diverter flow channel, the plurality of diverter holes and the extrusion flow channel being connected in sequence, the plurality of diverter holes being arranged in an array along the circumferential direction on the diverter ring, and the extension direction of each diverter hole being arranged at an angle to the front-to-back direction. The generation of diverter lines is effectively avoided, and the surface quality of the product is finally improved.

Description

Technical Field

[0001] The invention relates to the technical field of plastic extrusion, in particular to an extrusion die for a plastic extruder. Background Art

[0002] PVC material, or polyvinyl chloride, is one of the world's largest-volume plastic products with a wide range of applications. PVC pipes are mostly used for fluid transportation, such as water supply pipes, drainage pipes, etc. Traditional PVC pipes are usually produced using plastic extruders, which usually include an extruder barrel, an extrusion screw, an extrusion die, a main motor, and a feeding device. The extruder barrel is provided with a feeding port, and the feeding device is installed on the feeding port and is used to feed PVC plastic particles into the feeding port. The extrusion screw is installed in the extruder barrel and is driven by the main motor to rotate at high speed. The extrusion die is installed on the discharge port of the extruder barrel. The shear heat between the extrusion screw and the inner wall of the extruder barrel is used to plasticize and melt the fed plastic particles to make them into a molten material, and then the tubular material embryo is extruded through the extrusion die.

[0003] The extrusion die usually includes a core die, a diverter cone, a diverter ring and a mouth die. The core die is a rod-shaped body extending in a straight line direction. The straight line direction is generally the extrusion direction of the material. The diverter cone, the diverter ring and the core die are coaxially fixedly connected in sequence and are jointly sleeved on the inner side of the core die. The mouth die has a material inlet, a diverter flow channel is provided between the mouth die and the diverter cone, and an extrusion flow channel is provided between the mouth die and the core die. The diverter ring is usually provided with multiple diverter holes. The material inlet, the diverter flow channel, multiple diverter holes and the extrusion flow channel are connected in sequence, so that the material is diverted by the diverter cone and then diverted again through the diverter hole, and then enters the extrusion flow channel for compression, and finally extrudes a tubular material embryo.

[0004] Since the traditional diverter ring has a diverter hole which is usually a linear structure, the material flows rapidly into the extrusion channel through the diverter hole. Due to the fast flow rate of the material, the material is squeezed out before it can be compacted during compression in the extrusion channel. Since the material is not compressed sufficiently, diverter lines are easily generated, resulting in low surface quality of the final product. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide an extrusion die with a deflection diversion hole for a plastic extruder, which can avoid the generation of diversion lines and has a higher surface quality of the product.

[0006] In order to achieve the purpose of the above invention, the present invention adopts the following technical solutions:

[0007] An extrusion die with a deflection diverter hole for a plastic extruder, comprising:

[0008] A core mold assembly extending in a front-to-rear direction;

[0009] The flow splitter assembly comprises a flow splitter cone and a flow splitter ring, wherein the flow splitter cone, the flow splitter ring and the core mold assembly are coaxially fixedly connected in sequence from front to back;

[0010] A die assembly is coaxially fixedly sleeved on the outer sides of the core die assembly and the diverter assembly, the die assembly has a material inlet, a diverter flow channel is provided between the die assembly and the diverter cone, an extrusion flow channel is provided between the die assembly and the core die assembly, the diverter ring has a plurality of diverter holes penetrating the diverter ring, and the material inlet, the diverter flow channel, the plurality of diverter holes and the extrusion flow channel are sequentially connected;

[0011] The plurality of diverter holes are arranged in an array along the circumferential direction on the diverter ring, and the extension direction of each of the diverter holes is arranged to be deflected at an angle to the front-rear direction.

[0012] In the above technical solution, preferably, the diverter ring includes an inner ring body, an outer ring body and a plurality of diverter ribs, the inner ring body is coaxially sleeved on the inner side of the outer ring body, the plurality of diverter ribs are connected between the inner ring body and the outer ring body and are arranged in an array along the circumferential direction, a diverter hole is formed between two adjacent diverter ribs, and the extension direction of each diverter rib is set at an angle α to the radial direction of the diverter ring.

[0013] In the above technical solution, preferably, the angle α is 5°-10°.

[0014] In the above technical solution, preferably, each of the diverter ribs is inclined along the front-to-back direction and is arranged at an angle β with the end face of the diverter ring.

[0015] In the above technical solution, preferably, the β angle is 5°-10°.

[0016] In the above technical solution, preferably, the core mold assembly includes a core rod and at least one cooling sleeve, the core rod is provided with a cavity extending in the front-to-back direction, at least one cooling sleeve is coaxially arranged in the cavity and is in thermal contact with the cavity wall, the cooling sleeve is provided with a fluid pipeline arranged in a circumferential direction, and the cooling sleeve is provided with an inlet and an outlet connected to the fluid pipeline.

[0017] In the above technical solution, preferably, there are multiple cooling sleeves, and the multiple cooling sleeves are arranged at equal intervals in the front-to-back direction.

[0018] In the above technical solution, preferably, the cooling sleeve is a Hough structure, which includes an upper cylinder and a lower cylinder that are embraced with each other, and fluid pipelines are provided inside the upper cylinder and the lower cylinder, and the fluid pipelines in the upper cylinder and the fluid pipelines in the lower cylinder are independently arranged from each other.

[0019] In the above technical solution, preferably, both the upper cylinder and the lower cylinder are provided with electric heating coils.

[0020] In the above technical solution, preferably, the die assembly includes a tail die sleeve, an adjustment ring and a die that are coaxially fixedly connected in sequence from front to back, the diverter ring is fixedly connected between the tail die sleeve and the adjustment ring, a diverter channel is formed between the tail die sleeve and the diverter cone, and an extrusion channel is formed between the adjustment ring and the core rod, and between the die and the core rod.

[0021] The present invention arranges a plurality of diversion holes in an array along the circumferential direction on a diversion ring, and the extension direction of each diversion hole is arranged to be deflected at an angle with the front-rear direction, so that the flow direction of the material after being diverted by the diversion cone is deflected at an angle after being diverted again through the diversion hole, and the material rotates along the extrusion direction, and the flow rate of the material slows down, so that the material entering the extrusion flow channel can be accumulated and increased, and the material can be compressed more fully when being compressed through the extrusion flow channel, effectively avoiding the generation of diversion lines, and ultimately improving the surface quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional schematic diagram of the present invention;

[0023] Figure 2 is a cross-sectional schematic diagram of a cooling sleeve of the present invention;

[0024] Figure 3 is a schematic side view of a cooling sleeve of the present invention;

[0025] Figure 4 is a side view schematic diagram of the diverter ring of the present invention;

[0026] Figure 5 yes Figure 4 Schematic diagram of the cross section along line AA;

[0027] Figure 6 yes Figure 5 A partial enlarged schematic diagram of point B in the middle;

[0028] Wherein: 1, core mold assembly; 11, core rod; 111, cavity; 12, cooling sleeve; 121, fluid pipeline; 122, inlet; 123, outlet; 124, upper half cylinder; 125, lower half cylinder; 126, electric heating coil;

[0029] 2. flow dividing assembly; 21. flow dividing cone; 22. flow dividing ring; 221. inner ring body; 222. outer ring body; 223. flow dividing rib; 224. flow dividing hole;

[0030] 3. Mouth die assembly; 31. Tail die sleeve; 311. Material inlet; 32. Adjustment ring; 33. Mouth die;

[0031] 41. Diverter channel;

[0032] 42. Extrude the flow channel. DETAILED DESCRIPTION

[0033] In order to explain the technical content, structural features, objectives and effects of the invention in detail, the following will be described in detail with reference to the embodiments and accompanying drawings. Figure 1-Figure 5 The various positional relationships shown in correspondence.

[0034] like Figure 1 As shown, the extrusion die with deflection diverter hole in this case includes a core mold assembly 1, a diverter assembly 2 and a mouth mold assembly 3. The core mold assembly 1 includes a core rod 11, and the core rod 11 extends in the front-to-back direction. The diverter assembly 2 includes a diverter cone 21 and a diverter ring 22, and the diverter cone 21, the diverter ring 22 and the core mold assembly 1 are coaxially fixedly connected in sequence from front to back. The mouth mold assembly 3 is coaxially fixedly sleeved on the outside of the core mold assembly 1 and the diverter assembly 2, the mouth mold assembly 3 has a material inlet 311, a diverter flow channel 41 is provided between the mouth mold assembly 3 and the diverter cone 21, an extrusion flow channel 42 is provided between the mouth mold assembly 3 and the core mold assembly 1, and the diverter ring 22 has a plurality of diverter holes 224 passing through the diverter ring 22, and the material inlet 311, the diverter flow channel 41, the plurality of diverter holes 224 and the extrusion flow channel 42 are connected in sequence. Specifically, the die assembly 3 includes a tail die sleeve 31, an adjustment ring 32, and a die 33 that are coaxially fixedly connected in sequence from front to back, a diverter ring 22 is fixedly connected between the tail die sleeve 31 and the adjustment ring 32, a diverter flow channel 41 is formed between the tail die sleeve 31 and the diverter cone 21, and an extrusion flow channel 42 is formed between the adjustment ring and the core rod 11, and between the die 33 and the core rod 11. In this example, the die assembly and the core die assembly are designed as split structures, which is more convenient to install than the die and core die of the prior art that adopt an integrated structure.

[0035] like Figure 2-Figure 3As shown, in order to heat or cool the inside of the extrusion die, maintain the melting temperature of the material, and ensure that the material does not overheat and decompose, the core mold assembly 1 includes a cooling sleeve 12, a cavity 111 extending in the front-to-back direction is provided inside the core rod 11, the cooling sleeve 12 is coaxially arranged in the cavity 111 and is in thermal contact with the cavity wall, a fluid pipeline 121 arranged in the circumferential direction is provided inside the cooling sleeve 12, and an inlet 122 and an outlet 123 connected to the fluid pipeline 121 are provided on the cooling sleeve 12. Cooling water / cooling oil can be introduced into the fluid pipeline. Specifically, there are multiple cooling sleeves 12, and the multiple cooling sleeves 12 are arranged at equal intervals in the front-to-back direction. Each cooling sleeve 12 is a Hough structure, which includes an upper semi-cylinder 124 and a lower semi-cylinder 125 that are mutually embraced. Fluid pipelines 121 are provided inside the upper semi-cylinder 124 and the lower semi-cylinder 125. The fluid pipelines 121 in the upper semi-cylinder 124 and the fluid pipelines 121 in the lower semi-cylinder 125 are independently arranged. Electric heating coils 126 are provided in the upper semi-cylinder 124 and the lower semi-cylinder 125. The cooling sleeve 12 is heated by the electric heating coil 126, and the water / oil in the fluid pipeline is used as a heat transfer medium to heat the material in the extrusion mold; after the electric heating coil is powered off, the water / oil in the fluid pipeline can be discharged through the outlet, and chilled water or cooling oil can be introduced through the inlet to cool the extrusion mold, ensuring that the extrusion mold does not have an excessively high temperature and the material is not easily decomposed by high temperature. Of course, in other embodiments, the number of cooling sleeves is not limited to being multiple, but may be only one, and the structure of the cooling sleeve is not limited to being a Hough-type embracing structure, but may also be designed as an integral cylindrical structure.

[0036] like Figure 4-Figure 6 As shown, the diverter ring 22 includes an inner ring body 221, an outer ring body 222 and a plurality of diverter ribs 223. The inner ring body 221 is coaxially sleeved on the inner side of the outer ring body 222. The plurality of diverter ribs 223 are connected between the inner ring body 221 and the outer ring body 222 and arranged in an array along the circumferential direction. A diverter hole 224 is formed between two adjacent diverter ribs 223. The extension direction of each diverter rib 223 is set at an angle α to the radial direction of the diverter ring 22. Each diverter rib 223 is inclined in the front-to-back direction and is set at an angle β to the end face of the diverter ring 22. One of the two adjacent diverter ribs is inclined from front to back, and the other is inclined from back to front. Among them, the α angle is 5°-10°, and the β angle is 5°-10°. In this way, a plurality of diverter holes 224 are arranged in an array along the circumferential direction on the diverter ring 22, and the extension direction of each diverter hole 224 is deflected at a certain angle to the front-rear direction. Figure 1As shown, after the material diverted by the diverter cone 21 is diverted again through the diverter hole 224, the flow direction of the material is deflected by a certain angle, the material rotates along the extrusion direction, and the flow rate of the material slows down, so that the material entering the extrusion channel 42 can be accumulated and increased. When the material is compressed through the extrusion channel 42, it can be pressed more fully, effectively avoiding the generation of diverter lines, and ultimately improving the surface quality of the product.

[0037] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An extrusion die with a deflection diverter hole for a plastic extruder, comprising: The core mold assembly (1) extends in the front-rear direction; The flow splitter assembly (2) comprises a flow splitter cone (21) and a flow splitter ring (22), wherein the flow splitter cone (21), the flow splitter ring (22) and the core mold assembly (1) are coaxially fixedly connected in sequence from front to back; The die assembly (3) is coaxially fixedly sleeved on the outer sides of the core die assembly (1) and the diverter assembly (2); the die assembly (3) has a material inlet (311); a diverter channel (41) is provided between the die assembly (3) and the diverter cone (21); an extrusion channel (42) is provided between the die assembly (3) and the core die assembly (1); the diverter ring (22) has a plurality of diverter holes (224) penetrating the diverter ring (22); the material inlet (311), the diverter channel (41), the plurality of diverter holes (224) and the extrusion channel (42) are sequentially connected; characterized in that: The plurality of diverter holes (224) are arranged in an array along the circumferential direction on the diverter ring (22); the extension direction of each of the diverter holes (224) is arranged to be angled with respect to the front-rear direction; the diverter ring (22) comprises an inner ring body (221), an outer ring body (222), and a plurality of diverter ribs (223); the inner ring body (221) is coaxially sleeved on the inner side of the outer ring body (222); the plurality of diverter ribs (223) are connected between the inner ring body (221) and the outer ring body (222) and are arranged in an array along the circumferential direction; a diverter hole (224) is formed between two adjacent diverter ribs (223); the extension direction of each of the diverter ribs (223) is arranged to form an angle α with respect to the radial direction of the diverter ring (22); the angle α is 5°-10°; each of the diverter ribs (223) is inclined along the front-rear direction and is arranged to form an angle β with the end face of the diverter ring (22).

2. An extrusion die with a deflection diverter hole for a plastic extruder according to claim 1, characterized in that: The β angle is 5°-10°.

3. An extrusion die with a deflection diverter hole for a plastic extruder according to claim 1, characterized in that: The core mold assembly (1) comprises a core rod (11) and at least one cooling sleeve (12); a cavity (111) extending in a front-to-rear direction is provided inside the core rod (11); at least one cooling sleeve (12) is coaxially arranged in the cavity (111) and is in heat-conducting contact with the cavity wall; a fluid pipeline (121) arranged in a circumferential direction is provided inside the cooling sleeve (12); and an inlet (122) and an outlet (123) connected to the fluid pipeline (121) are provided on the cooling sleeve (12).

4. An extrusion die with a deflection diverter hole for a plastic extruder according to claim 3, characterized in that: There are a plurality of cooling sleeves (12), and the plurality of cooling sleeves (12) are arranged at equal intervals in the front-to-back direction.

5. The extrusion die with a deflection diverter hole for a plastic extruder according to claim 3, characterized in that: The cooling sleeve (12) is a Hough-type structure, comprising an upper cylinder (124) and a lower cylinder (125) that are mutually embraced, and fluid pipelines (121) are provided inside the upper cylinder (124) and the lower cylinder (125), and the fluid pipeline (121) in the upper cylinder (124) and the fluid pipeline (121) in the lower cylinder (125) are independently arranged.

6. An extrusion die with a deflection diverter hole for a plastic extruder according to claim 5, characterized in that: The upper cylinder (124) and the lower cylinder (125) are both provided with electric heating coils (126).

7. An extrusion die with a deflection diverter hole for a plastic extruder according to claim 1, characterized in that: The die assembly (3) comprises a tail die sleeve (31), an adjustment ring (32) and a die (33) which are coaxially fixedly connected in sequence from front to back, the diverter ring (22) is fixedly connected between the tail die sleeve (31) and the adjustment ring (32), a diverter flow channel (41) is formed between the tail die sleeve (31) and the diverter cone (21), and an extrusion flow channel (42) is formed between the adjustment ring and the core rod (11), and between the die (33) and the core rod (11).

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