Pipe extrusion screw

Abstract

The utility model provides a pipe extrusion screw which solves the problem that an existing screw structure is not ideal in mixing and plasticizing effect. The first plasticizing section is arranged at the discharging end of the feeding section; the second plasticizing section is arranged between the first plasticizing section and the homogenizing section, and the second plasticizing section is longer than the first plasticizing section; the auxiliary screw flights are arranged on the second plasticizing section, the height of the main screw flights is larger than that of the auxiliary screw flights, the distances between the auxiliary screw flights and the front and back adjacent main screw flights form a main screw groove and an auxiliary screw groove respectively, the depth of the main screw grooves is gradually shallower in the feeding direction, and the depth of the auxiliary screw grooves is gradually deeper in the feeding direction. A mixed material enters the first plasticizing section through the feeding section to be preliminarily plasticized and then enters the second plasticizing section, part of the unplasticized mixed material is located in the main spiral groove, and the mixed material is completely plasticized along with the fact that the depth of the main spiral groove is gradually shallower in the feeding direction and the shearing force is gradually increased. And the plasticized mixed material is changed into a melt, and the melt flows into the auxiliary screw groove from the top of the auxiliary screw flight.

Description

Technical Field

[0001] This utility model relates to the field of extrusion equipment technology, specifically to a pipe extrusion screw. Background Technology

[0002] Currently, in the pipe extrusion molding process, the material is extruded through the screw of an extruder. During pipe extrusion, various additives need to be added to the raw materials to improve pipe performance. Then, the rotation of the screw inside the barrel and the heating of the barrel cause the mixture to become a molten polymer. However, the existing screw structure generally has a poor plasticizing effect on the mixture, which consequently affects the quality of the pipe. Utility Model Content

[0003] To overcome the shortcomings of the prior art, this utility model provides a pipe extrusion screw, which solves the problem that the existing screw structure does not achieve the desired mixing and plasticizing effect.

[0004] The technical solution adopted in this utility model is as follows:

[0005] A pipe extrusion screw includes a rod body with a main screw rib. The rod body is provided with a feeding section, a homogenization section, and a mixing section sequentially along the feeding direction. The screw is characterized by further comprising:

[0006] The first plasticizing section has a discharge end for the feeding section;

[0007] The second plasticizing section is located between the first plasticizing section and the homogenization section, and the length of the second plasticizing section is greater than the length of the first plasticizing section.

[0008] The secondary screw ridge is set on the second plasticizing section. The height of the main screw ridge is greater than the height of the secondary screw ridge. The distance between the secondary screw ridge and the adjacent main screw ridges forms the main screw groove and the secondary screw groove, respectively. The depth of the main screw groove gradually becomes shallower along the feeding direction, and the depth of the secondary screw groove gradually becomes deeper along the feeding direction.

[0009] The width of the main screw groove gradually decreases along the feeding direction, while the width of the auxiliary screw groove gradually increases along the feeding direction.

[0010] The mixing section includes a first mixing section and a second mixing section, with a gap between the first mixing section and the second mixing section.

[0011] The No. 1 mixing section is circumferentially distributed with adjacent feed troughs and discharge troughs, and a shearing groove is provided between the feed troughs and the discharge troughs.

[0012] The second mixing section is provided with at least two sets of rhomboid protrusions in the circumferential direction, with adjacent rhomboid protrusions arranged in an alternating pattern.

[0013] The homogenization section is circumferentially distributed with stirring columns.

[0014] The top surface of the main thread is provided with a wear-resistant alloy layer.

[0015] The beneficial effects of this utility model are:

[0016] After the mixture enters the first plasticizing section through the feeding section, it undergoes preliminary plasticization, and then enters the second plasticizing section. Some of the unplasticized mixture is located in the main screw channel. As the depth of the main screw channel gradually decreases along the feeding direction, the shear force gradually increases, which completely plasticizes the mixture. After plasticization, the mixture becomes a melt and flows from the top of the auxiliary screw rib into the auxiliary screw channel. This application not only has a good plasticizing effect through two plasticizing sections, but also reduces the length of the plasticizing section. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the present invention.

[0018] Figure 2 This is a utility model Figure 1 Enlarged diagram of point A in the middle.

[0019] Figure 3 This is a utility model Figure 1 Enlarged diagram of point B in the middle.

[0020] Figure 4 This is a cross-sectional schematic diagram of the main screw thread of this utility model.

[0021] 1. Main screw rib, 2. Feeding section, 3. Homogenization section, 4. Mixing section, 41. No. 1 mixing section, 42. No. 2 mixing section, 43. Spacing, 5. No. 1 plasticizing section, 6. No. 2 plasticizing section, 7. Auxiliary screw rib, 8. Main screw groove, 9. Auxiliary screw groove, 10. Feed chute, 11. Discharge chute, 12. Shearing groove, 13. Diamond-shaped protrusions, 14. Stirring column, 15. Wear-resistant alloy layer. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0023] In the embodiments, such as Figure 1 , Figure 2 As shown, a pipe extrusion screw includes a rod body with a main screw ridge 1. The rod body is sequentially provided with a feeding section 2, a homogenization section 3, and a mixing section 4 along the feeding direction. It also includes:

[0024] The first plasticizing section 5 is equipped with the discharge end of the feeding section 2;

[0025] The second plasticizing section 6 is located between the first plasticizing section 5 and the homogenizing section 3, and the length of the second plasticizing section 6 is greater than the length of the first plasticizing section 5.

[0026] A secondary screw ridge 7 is provided on the second plasticizing section 6. The height of the main screw ridge 1 is greater than the height of the secondary screw ridge 7. The distance between the secondary screw ridge 7 and the adjacent main screw ridges 1 forms the main screw groove 8 and the secondary screw groove 9, respectively. The depth of the main screw groove 8 gradually becomes shallower along the feeding direction, and the depth of the secondary screw groove 9 gradually becomes deeper along the feeding direction.

[0027] After the mixed material enters the first plasticizing section 5 through the feeding section 2, it undergoes preliminary plasticizing. Then it enters the second plasticizing section 6. Some of the unplasticized mixed material is located in the main screw channel 8. As the depth of the main screw channel 8 gradually decreases along the feeding direction, the shear force gradually increases, which completely plasticizes the mixed material. After plasticizing, the mixed material becomes a melt and flows from the top of the auxiliary screw ridge 7 into the auxiliary screw channel 9. This application not only has a good plasticizing effect through two plasticizing sections, but also reduces the length of the plasticizing section.

[0028] In the embodiments, such as Figure 2 As shown, the width of the main screw channel 8 gradually decreases along the feeding direction, while the width of the auxiliary screw channel 9 gradually increases along the feeding direction. The increasing volume of the auxiliary screw channel 9 allows for a greater amount of molten material to be accommodated, thereby increasing injection molding speed and reducing the probability of product defects.

[0029] In the embodiments, such as Figure 1 As shown, the mixing section 4 includes a first mixing section 41 and a second mixing section 42, with a gap 43 between the first mixing section 41 and the second mixing section 42. After the molten material is mixed in the first mixing section 41, it reaches the gap for further mixing, and then enters the second mixing section 42 for further mixing, thereby improving the uniformity of the molten material mixing.

[0030] In the embodiments, such as Figure 3 As shown, the first mixing section 41 has feed troughs 10 and discharge troughs 11 arranged adjacent to each other in a circumferential manner, and a shearing groove 12 is provided between the feed troughs 10 and the discharge troughs 11. This diverts and mixes the molten material while improving the plasticizing quality of the molten material.

[0031] In the embodiments, such as Figure 1 As shown, the second mixing section 42 is provided with at least two sets of rhomboid protrusions 13 in the circumferential direction, with adjacent rhomboid protrusions 13 arranged in an alternating pattern. The molten material passing through the alternating rhomboid protrusions 13 can be thoroughly mixed, resulting in a more uniform mixture and improved product quality.

[0032] In the embodiments, such as Figure 1 As shown, stirring columns 14 are evenly distributed circumferentially in the homogenization section 3. The stirring columns 14 thoroughly stir the mixture, improving the uniformity of the molten material.

[0033] In the embodiments, such as Figure 4As shown, the top surface of the main screw thread 1 is provided with a wear-resistant alloy layer 15. The wear-resistant alloy layer 15 can be a tungsten carbide alloy layer, which plays a wear-resistant role, reduces the wear of the main screw thread 1, and improves the service life of the screw.

[0034] Obviously, the above embodiments of this utility model are merely illustrative examples and not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, these obvious variations or modifications derived from the essential spirit of this utility model still fall within the protection scope of this utility model.

Claims

1. A pipe extrusion screw, comprising a rod body, wherein the rod body is provided with a main screw ridge (1), and the rod body is provided with a feeding section (2), a homogenization section (3), and a mixing section (4) sequentially along the feeding direction, characterized in that, Also includes: The first plasticizing section (5) is equipped with the discharge end of the feeding section (2); The second plasticizing section (6) is located between the first plasticizing section (5) and the homogenization section (3), and the length of the second plasticizing section (6) is greater than the length of the first plasticizing section (5); A secondary screw ridge (7) is set on the second plasticizing section (6). The height of the main screw ridge (1) is greater than the height of the secondary screw ridge (7). The distance between the secondary screw ridge (7) and the adjacent main screw ridges (1) forms the main screw groove (8) and the secondary screw groove (9), respectively. The depth of the main screw groove (8) gradually becomes shallower along the feeding direction, and the depth of the secondary screw groove (9) gradually becomes deeper along the feeding direction.

2. The tube extrusion screw as described in claim 1, characterized in that: The width of the main screw groove (8) gradually decreases along the feeding direction, while the width of the auxiliary screw groove (9) gradually increases along the feeding direction.

3. The tube extrusion screw as described in claim 1, characterized in that: The mixing section (4) includes a first mixing section (41) and a second mixing section (42), with a gap (43) between the first mixing section (41) and the second mixing section (42).

4. The tube extrusion screw as described in claim 3, characterized in that: The No. 1 mixing section (41) is circumferentially distributed with adjacent feed troughs (10) and discharge troughs (11), and a shearing groove (12) is provided between the feed troughs (10) and the discharge troughs (11).

5. A tube extrusion screw as described in claim 3, characterized in that: The second mixing section (42) is provided with at least two sets of rhomboid protrusions (13) in the circumferential direction, and the adjacent rhomboid protrusions (13) are arranged in an alternating manner.

6. The tube extrusion screw as described in claim 1, characterized in that: The homogenization section (3) is circumferentially distributed with stirring columns (14).

7. The tube extrusion screw as described in claim 1, characterized in that: The top surface of the main thread (1) is provided with a wear-resistant alloy layer (15).

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