PP-R pipe extrusion die
Patent Information
- Application Number
- CN202522125284.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2026-10-20
- Estimated Expiration
- 2035-09-30
AI Technical Summary
由于PP-R管材的熔融指数较低，熔体黏度较高，流动性不好，传统的PP-R管材挤出模具在实际生产过程中难以使PP-R原料充分塑化，容易出现合流线明显、晶点和气孔多、色母分散不良等表面缺陷问题，造成产品质量不稳定
1、提升塑化效果与熔体均匀性，通过设置由斜孔板和直孔板构成的增强塑化流道段，将熔融塑料进行多次分流、剪切和重新汇合，解决了传统模具中PP-R熔体塑化不均问题；
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Figure CN224867821U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of extrusion dies, and more specifically, to an extrusion die for PP-R pipes. Background Technology
[0002] PP-R (random copolymer polypropylene) pipes are widely used in construction, home decoration, and many other fields. They possess advantages such as light weight, corrosion resistance, high strength, non-scaling properties, and long service life, playing a crucial role, especially in hot and cold water supply systems. As market demands for the performance and quality of PP-R pipes increase, research into their production equipment and processes is also deepening. Extrusion molds, as a core and essential component in PP-R pipe production, directly impact pipe quality and production efficiency.
[0003] During the extrusion process, as PP-R raw materials transition from a crystalline state to a highly elastic state and then to a molten viscous flow state, improper control of plasticizing temperature and pressure can lead to abnormal molecular configuration changes during these transitions. Because PP-R pipes have a low melt index, high melt viscosity, and poor flowability, traditional PP-R pipe extrusion dies often fail to fully plasticize the raw materials during actual production. This can result in surface defects such as prominent flow lines, numerous crystal points and pores, and poor masterbatch dispersion, leading to unstable product quality. These surface defects not only affect the aesthetics of the pipes but also reduce their corrosion resistance and service life, impacting their effectiveness in practical engineering applications. Utility Model Content
[0004] The purpose of this invention is to overcome the shortcomings of existing technologies that make it difficult to fully plasticize PP-R raw materials, resulting in surface defects. This invention provides a PP-R pipe extrusion mold that allows PP-R raw materials to be fully plasticized in the mold, reducing the occurrence of surface defects, effectively improving product quality and reducing scrap rate.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A PP-R pipe extrusion die is provided, comprising an outer die assembly, a core assembly, and an orifice assembly. The orifice assembly is connected to the outer die assembly, and the core assembly is connected to the outer die assembly and disposed within the orifice assembly. The outer die assembly has a flow channel for introducing molten plastic. The flow channel is sequentially arranged with a preliminary plasticizing flow channel section, a reinforcing plasticizing flow channel section, and a forming flow channel section along the flow direction of the molten plastic. The forming flow channel section is disposed between the orifice assembly and the outer die assembly. The reinforcing plasticizing flow channel section has an inclined perforated plate and a straight perforated plate. The inclined perforated plate has multiple inclined branch channels, and the straight perforated plate has multiple horizontal branch channels. The inclined branch channels are connected to the horizontal branch channels.
[0006] This utility model's PP-R pipe extrusion die primarily optimizes the plasticizing process of molten plastic. When the molten plastic enters the flow channel inside the outer mold assembly, it first undergoes initial plasticizing through shearing and tumbling in the preliminary plasticizing flow channel section. Subsequently, it enters the inclined and straight perforated plates in the reinforcing plasticizing flow channel. The inclined flow channel in the inclined perforated plate changes the flow direction of the molten plastic within the flow channel, enhancing the shearing and tumbling effect. This causes exchange between the inner and outer layers of molten plastic, helping to evenly disperse additives such as color masterbatch. In the horizontal flow channel in the straight perforated plate, the flow direction of the molten plastic is changed to horizontal, separating large streams of molten plastic into multiple streams. Finally, these streams converge in the forming flow channel section between the die assembly and the core assembly, forming a high-quality PP-R pipe. This utility model, by setting up a reinforced plasticizing flow channel section composed of inclined and straight perforated plates, performs multiple stream divisions, shearing, and recombination of the molten plastic, solving the problem of uneven plasticizing of PP-R melt in traditional molds. This effectively eliminates surface defects such as merging lines, improving the appearance quality and service life of the pipe.
[0007] Further, the inclined perforated plate includes a first end face away from the die assembly and a second end face close to the die assembly. The first end face is provided with a plurality of first circular holes evenly distributed along a first ring with an inner diameter of R1, and a plurality of second circular holes evenly distributed along a second ring with an inner diameter of R2, wherein the inner diameter R1 of the first ring is smaller than the radius R2 of the second ring. The second end face is provided with a plurality of third circular holes evenly distributed along a third ring with an inner diameter of R3, and a plurality of fourth circular holes evenly distributed along a fourth ring with an inner diameter of R4, wherein the inner diameter R3 of the third ring is smaller than the inner diameter R4 of the fourth ring. The first circular holes and the fourth circular holes are connected through the inclined flow channel, and the second circular holes and the third circular holes are connected through the inclined flow channel. The inclined perforated plate allows molten plastic from the first ring to pass through the first hole and flow through the inclined branch channel to the fourth ring on the second end face. At the same time, it allows molten plastic from the second ring to flow to the third ring, achieving forced cross-mixing of molten plastic in the radial position. This guides the molten plastic in the inner ring to the outer ring and the molten plastic in the outer ring to the inner ring, thus completely disrupting its layered flow structure. This effectively eliminates obvious flow lines, keeps the radial temperature and additive components such as color masterbatch uniform, and ultimately significantly improves the plasticization uniformity, surface quality, and mechanical property consistency of the pipe.
[0008] Furthermore, the angle between the central axis of the inclined flow channel and the central axis of the inclined perforated plate is 15°~20°. The 15°~20° inclination angle design in the inclined flow channel serves two purposes: firstly, it generates sufficient radial force to enhance the cross-mixing and recombination of the molten plastic, effectively disrupting flow layers and eliminating confluence lines; secondly, it avoids a sharp increase in flow resistance caused by an excessively large angle. Thus, while ensuring excellent plasticizing and mixing effects, it maintains a smooth and stable forward flow of the melt, guaranteeing the stability and production efficiency of the extrusion process.
[0009] Furthermore, the first, second, third, and fourth circular holes have the same diameter. This identical hole diameter design ensures balanced flow resistance as the melt flows through the various channels on the inclined and straight orifice plates, avoiding localized flow velocity unevenness or material stagnation caused by differences in hole diameter. This achieves cross-mixing of the melt while ensuring the stability and consistency of the flow field throughout the extrusion process, which is beneficial for forming pipes with uniform structure and no defects.
[0010] Furthermore, an annular guide ring is provided on the first end face and / or the second end face. The annular guide ring is disposed between the first ring and the second ring and / or between the third ring and the fourth ring. The cross-section of the guide ring is triangular and protrudes from the first end face and / or the second end face. The annular triangular guide ring can guide and comb the molten plastic flowing over its surface, making it turn more smoothly and enter the corresponding inclined flow channel, thereby reducing eddies and dead zones, effectively reducing the pressure loss of the melt on the end face of the inclined orifice plate, ensuring balanced feeding in each inclined flow channel, and further improving the uniformity of melt mixing and flow stability.
[0011] Furthermore, the distance between the inclined perforated plate and the die assembly is greater than the distance between the straight perforated plate and the die assembly. The design of the molten plastic first passing through the inclined perforated plate and then entering the straight perforated plate provides a stable section for the melt, which is in a turbulent state after cross-mixing through the inclined perforated plate. This allows for a sufficient balance of flow rate and temperature before final shaping, ensuring flow field stability when entering the forming channel section and avoiding surface defects that might result from turbulent flow directly entering the shaping stage.
[0012] Furthermore, a fifth ring is provided on the straight orifice plate, and the horizontal flow channels are evenly arranged in the fifth ring. The inner diameter R5 of the fifth ring is smaller than the inner diameter R3 of the third ring, and the outer diameter R6 of the fifth ring is larger than the outer diameter R7 of the fourth ring. By controlling the inner and outer diameters of the fifth ring, it is ensured that the horizontal flow channels of the straight orifice plate can completely cover and receive all the molten plastic flowing out from the inclined orifice plate after cross-mixing, achieving full capture of the molten plastic and preventing the melt from flowing around or into dead zones at the contact point between the straight and inclined orifice plates. This lays the foundation for the final uniform and stable extrusion of the pipe.
[0013] Furthermore, the cross-sectional shape of the horizontal flow channel is circular, elliptical, or polygonal, and the total cross-sectional area of the horizontal flow channel is not less than the total cross-sectional area of the inclined flow channel. By ensuring that the total flow capacity of the horizontal flow channel is not less than that of the inclined flow channel, the flow obstruction and sudden pressure increase caused by the shrinkage of the cross-sectional area at the flow channel transition point are effectively avoided, thereby maintaining pressure balance and stable flow rate, which is beneficial to forming a high-quality tube blank.
[0014] Furthermore, it also includes a spiral body disposed inside the outer mold assembly. The outer wall of the spiral body is provided with spiral grooves, and the preliminary plasticizing flow channel section is disposed between the spiral grooves and the outer mold assembly. The spiral body, through the spiral grooves on its outer wall, forms a preliminary plasticizing flow channel with the outer mold assembly, allowing the molten plastic to undergo continuous shearing and tumbling during its advancement, thus achieving preliminary plasticizing and providing a stable and fully premixed molten plastic for subsequent entry into the reinforcing plasticizing flow channel section.
[0015] Furthermore, it also includes a mold base, a shrink sleeve, and a shrink core. The die assembly includes a die and a die platen. One end of the outer mold assembly is connected to the mold base, and the other end is connected to the shrink sleeve. The shrink core is disposed inside the shrink sleeve. The spire abuts against the inclined hole plate, the inclined hole plate abuts against the straight hole plate, and both the shrink sleeve and the shrink core abut against the straight hole plate. The shrink core is provided with fastening bolts passing through the straight hole plate, the inclined hole plate, and the spire. The shrink core is connected to the die core assembly. The die platen is sleeved on the die and connected to the shrink sleeve. The outer mold assembly is fixed on the mold base. The shrink sleeve and the shrink core are locked together by fastening bolts to secure the inclined hole plate, the straight hole plate, and the spire. The die platen is connected to the shrink sleeve, thereby locking the internal die. The tight fit between the various components ensures the sealing and stability of the flow channel, thus providing a stable molding path for the plastic fluid.
[0016] Compared with the prior art, the beneficial effects of this utility model are: 1. Improve plasticizing effect and melt uniformity. By setting up an enhanced plasticizing flow channel section composed of inclined and straight perforated plates, the molten plastic is diverted, sheared and recombined multiple times, which solves the problem of uneven plasticizing of PP-R melt in traditional molds. 2. Effectively eliminates surface defects such as flow lines. Due to the special flow channel design of the inclined hole plate, the plasticizing effect is enhanced, thereby reducing obvious surface defects such as flow lines, crystal points and pores, and improving the appearance quality and service life of the pipe. 3. The mold flow channel adopts a three-stage design of preliminary plasticization, enhanced plasticization and molding, which provides a gradual and functionally clear optimization path for the plasticization of PP-R raw materials, ensuring the stability and consistency of the final product quality and reducing the scrap rate in the production process. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of a PP-R pipe extrusion die; Figure 2 An exploded view of a PP-R pipe extrusion die; Figure 3 This is the front view of the inclined plate; Figure 4 This is the rear view of the inclined hole plate; Figure 5 This is a schematic diagram of a straight perforated plate.
[0018] In the attached diagram: 100, outer mold assembly; 200, mold core assembly; 300, die assembly; 310, die; 320, die pressure plate; 410, preliminary plasticizing runner section; 420, reinforced plasticizing runner section; 430, molding runner section; 500, inclined perforated plate; 510, inclined branch runner; 520, first end face; 521, first ring; 522, first circular hole; 523, second ring; 52 4. Second circular hole; 525. First boss; 530. Second end face; 531. Third ring; 532. Third circular hole; 533. Fourth ring; 534. Fourth circular hole; 540. Annular guide ring; 600. Straight hole plate; 610. Horizontal flow channel; 620. Fifth ring; 700. Spiral body; 710. Spiral groove; 800. Mold base; 910. Shrink sleeve; 920. Shrink core. Detailed Implementation
[0019] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.
[0020] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0021] Example 1 This embodiment is a first embodiment of a PP-R pipe extrusion die, including an outer die assembly 100, a core die assembly 200, and an orifice die assembly 300. The orifice die assembly 300 is connected to the outer die assembly 100, and the core die assembly 200 is connected to the outer die assembly 100 and disposed within the orifice die assembly 300. The outer die assembly 100 is provided with a flow channel for introducing molten plastic. The flow channel is provided sequentially along the direction of molten plastic flow as a preliminary plasticizing flow channel section 410, a reinforcing plasticizing flow channel section 420, and a forming flow channel section 430. The forming flow channel section 430 is disposed between the orifice die assembly 300 and the outer die assembly 100. The reinforcing plasticizing flow channel section 420 is provided with an inclined perforated plate 500 and a straight perforated plate 600. The inclined perforated plate 500 is provided with multiple inclined branch channels 510, and the straight perforated plate 600 is provided with multiple horizontal branch channels 610. The inclined branch channels 510 and the horizontal branch channels 610 are connected.
[0022] like Figure 1 As shown, the PP-R pipe extrusion die of this utility model mainly optimizes the plasticizing process of molten plastic. When the molten plastic enters the flow channel inside the outer mold assembly 100, it first undergoes preliminary plasticizing through shearing and tumbling in the preliminary plasticizing flow channel section 410. Subsequently, it enters the inclined perforated plate 500 and straight perforated plate 600 in the reinforcing plasticizing flow channel. In the inclined branch channel 510 in the inclined perforated plate 500, the flow direction of the molten plastic in the flow channel is changed, enhancing the shearing and tumbling effect. The molten plastic in the inner and outer layers exchanges, helping to evenly disperse additives such as color masterbatch. In the horizontal branch channel 610 in the straight perforated plate 600, the flow direction of the molten plastic is changed to a horizontal direction, separating large strands of molten plastic into multiple strands. Finally, they converge in the forming flow channel section 430 between the die assembly 300 and the core assembly 200 to form a high-quality PP-R pipe. This invention solves the problem of uneven plasticization of PP-R melt in traditional molds by setting up an enhanced plasticizing flow channel section 420 composed of an inclined perforated plate 500 and a straight perforated plate 600, which performs multiple diversions, shearings and recombinations of molten plastic. This effectively eliminates surface defects such as flow lines and improves the appearance quality and service life of the pipe.
[0023] like Figure 3 , Figure 4 As shown, the inclined plate 500 includes a first end face 520 away from the die assembly 300 and a second end face 530 close to the die assembly 300. The first end face 520 is provided with a plurality of first circular holes 522 evenly distributed along the inner diameter of a first ring 521 of R1, and a plurality of second circular holes 524 evenly distributed along the inner diameter of a second ring 523 of R2. The inner diameter R1 of the first ring 521 is smaller than the radius R2 of the second ring 523. The second end face... The 530 is provided with a plurality of third circular holes 532 evenly distributed along the inner diameter of the third ring 531 with an inner diameter of R3, and a plurality of fourth circular holes 534 evenly distributed along the inner diameter of the fourth ring 533 with an inner diameter of R4, wherein the inner diameter R3 of the third ring 531 is smaller than the inner diameter R4 of the fourth ring 533; the first circular hole 522 and the fourth circular hole 534 are connected through the inclined flow channel 510, and the second circular hole 524 and the third circular hole 532 are connected through the inclined flow channel 510. The inclined perforated plate 500 allows molten plastic from the first ring 521 to pass through the first circular hole 522 and flow through the inclined diversion channel 510 to the fourth ring 533 on the second end face 530. At the same time, it allows molten plastic from the second ring 523 to flow to the third ring 531, achieving forced cross-mixing of molten plastic in the radial position. This guides the molten plastic in the inner ring to the outer ring and the molten plastic in the outer ring to the inner ring, thereby completely disrupting its layered flow structure. This effectively eliminates obvious flow lines, keeps the radial temperature and additive components such as color masterbatch uniform, and ultimately significantly improves the plasticization uniformity, surface quality, and mechanical property consistency of the pipe.
[0024] like Figure 1 As shown, the angle between the central axis of the inclined manifold 510 and the central axis of the inclined perforated plate 500 is 15°~20°. The 15°~20° inclination angle design of the inclined manifold 510 can, on the one hand, generate sufficient radial force to enhance the cross-mixing and recombination of the molten plastic, effectively disrupting the flow layers and eliminating the merging lines; on the other hand, it avoids the sharp increase in flow resistance caused by an excessively large angle. Thus, while ensuring excellent plasticizing and mixing effects, it maintains the smooth and stable forward flow of the melt, ensuring the stability and production efficiency of the extrusion process.
[0025] The first circular hole 522, the second circular hole 524, the third circular hole 532, and the fourth circular hole 534 have the same diameter. The design of the same hole diameter ensures that the flow resistance of the melt is balanced when it flows through the various branch channels on the inclined orifice plate 500 and the straight orifice plate 600. It avoids local uneven flow velocity or material stagnation caused by differences in hole diameter. Thus, while achieving cross-mixing of the melt, it ensures the stability and consistency of the flow field throughout the extrusion process, which is conducive to forming a pipe with a uniform structure and no defects.
[0026] like Figure 1, Figure 3 As shown, an annular guide ring 540 is provided on the first end face 520 and / or the second end face 530. The annular guide ring 540 is located between the first ring 521 and the second ring 523 and / or between the third ring 531 and the fourth ring 533. The cross-section of the guide ring is triangular and protrudes from the first end face 520 and / or the second end face 530. The annular triangular guide ring can guide and comb the molten plastic flowing over its surface, making it turn more smoothly and enter the corresponding inclined flow channel 510, thereby reducing eddies and flow dead zones, effectively reducing the pressure loss of the melt on the end face of the inclined orifice plate 500, ensuring balanced feeding in each inclined flow channel 510, and further improving the uniformity of melt mixing and flow stability.
[0027] Example 2 This embodiment is the second embodiment of a PP-R pipe extrusion die. This embodiment is similar to the first embodiment, except that, as shown in the example... Figure 1 As shown, the distance between the inclined perforated plate 500 and the die assembly 300 is greater than the distance between the straight perforated plate 600 and the die assembly 300. The design of the molten plastic first passing through the inclined perforated plate 500 and then entering the straight perforated plate 600 provides a stable section for the melt, which is in a turbulent state after cross-mixing through the inclined perforated plate 500. This allows the flow rate and temperature to be fully balanced before final shaping, ensuring the stability of the flow field when entering the molding runner section 430 and avoiding surface defects that may be caused by turbulent flow directly entering the shaping stage.
[0028] like Figure 5 As shown, a fifth ring 620 is provided on the straight orifice plate 600, and horizontal flow channels 610 are uniformly arranged in the fifth ring 620. The inner diameter R5 of the fifth ring 620 is smaller than the inner diameter R3 of the third ring 531, and the outer diameter R6 of the fifth ring 620 is larger than the outer diameter R7 of the fourth ring 533. By controlling the inner and outer diameters of the fifth ring 620, it is ensured that the horizontal flow channels 610 of the straight orifice plate 600 can completely cover and receive all the molten plastic flowing out from the inclined orifice plate 500 after cross-mixing, realizing the complete capture of molten plastic and preventing the melt from flowing around or into dead zones at the contact point between the straight orifice plate 600 and the inclined orifice plate 500, thus laying the foundation for the final uniform and stable extrusion of the pipe.
[0029] The horizontal flow channel 610 has a circular, elliptical, or polygonal cross-sectional shape, and its total cross-sectional area is not less than that of the inclined flow channel 510. By ensuring that the total flow capacity of the horizontal flow channel 610 is not less than that of the inclined flow channel 510, the flow obstruction and sudden pressure increase caused by the shrinkage of the cross-sectional area at the flow channel transition point are effectively avoided, thereby maintaining pressure balance and stable flow rate, which is conducive to the formation of high-quality tube blanks.
[0030] Example 3 This embodiment is the second embodiment of a PP-R pipe extrusion die. This embodiment is similar to the first embodiment, except that, as shown in the example... Figure 1 , Figure 2 As shown, the system also includes a spiral 700 disposed inside the outer mold assembly 100. The spiral 700 has a spiral groove 710 on its outer wall, and a preliminary plasticizing flow channel section 410 is disposed between the spiral groove 710 and the outer mold assembly 100. The spiral 700, through its spiral groove 710 on its outer wall, forms a preliminary plasticizing flow channel with the outer mold assembly 100, allowing the molten plastic to undergo continuous shearing and tumbling during its advancement, achieving preliminary plasticizing and providing a stable and fully premixed molten plastic for subsequent entry into the reinforcing plasticizing flow channel section 420. In this embodiment, a first boss 525 is provided on the first end face 520 of the inclined perforated plate 500, and a first groove is provided on the spiral 700 to mate with the first boss 525. During installation, the engagement of the first boss 525 and the first groove facilitates the positioning between the inclined perforated plate 500 and the spiral 700.
[0031] like Figure 1 , Figure 2 As shown, the PP-R pipe extrusion die in this embodiment also includes a die base 800, a shrink sleeve 910, and a shrink core 920. The die assembly 300 includes a die 310 and a die pressure plate 320. One end of the outer die assembly 100 is connected to the die base 800, and the other end is connected to the shrink sleeve 910. The shrink core 920 is disposed inside the shrink sleeve 910. The spire 700 abuts against the inclined hole plate 500, and the inclined hole plate 500 abuts against the straight hole plate 600. The shrink sleeve 910 and the shrink core 920 both abut against the straight hole plate 600. The shrink core 920 is provided with fastening bolts that pass through the straight hole plate 600, the inclined hole plate 500, and the spire 700. The shrink core 920 is connected to the die core assembly 200. The die pressure plate 320 is sleeved on the die 310 and connected to the shrink sleeve 910. The outer mold assembly 100 is fixed on the mold base 800. The shrink sleeve 910 and the shrink core 920 are locked together with the inclined hole plate 500, the straight hole plate 600 and the spiral body 700 by fastening bolts. The die plate 320 is connected to the shrink sleeve 910 to lock the internal die 310. The close cooperation between the various components ensures the sealing and stability of the flow channel, thus providing a stable molding path for the plastic fluid.
[0032] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.
[0033] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are 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 describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A PP-R pipe extrusion die, characterized in that, The device includes an outer mold assembly (100), a core mold assembly (200), and a die assembly (300). The die assembly (300) is connected to the outer mold assembly (100). The core mold assembly (200) is connected to the outer mold assembly (100) and disposed within the die assembly (300). The outer mold assembly (100) has a flow channel for introducing molten plastic. The flow channel is provided with a preliminary plasticizing flow channel section (410) and a reinforcing plasticizing flow channel section (420) sequentially along the direction of the molten plastic flow. 0) and a molding flow channel section (430), wherein the molding flow channel section (430) is disposed between the die assembly (300) and the outer die assembly (100), wherein the reinforcing plasticizing flow channel section (420) is provided with an inclined hole plate (500) and a straight hole plate (600), wherein the inclined hole plate (500) is provided with a plurality of inclined branch channels (510), wherein the straight hole plate (600) is provided with a plurality of horizontal branch channels (610), and the inclined branch channels (510) are connected to the horizontal branch channels (610).
2. The PP-R pipe extrusion die according to claim 1, characterized in that, The oblique perforated plate (500) includes a first end face (520) away from the die assembly (300) and a second end face (530) close to the die assembly (300). The first end face (520) is provided with a plurality of first circular holes (522) evenly distributed along a first ring (521) with an inner diameter of R1, and a plurality of second circular holes (524) evenly distributed along a second ring (523) with an inner diameter of R2. The inner diameter R1 of the first ring (521) is smaller than the radius R2 of the second ring (523). The second end face (530)... The device is provided with a plurality of third circular holes (532) evenly distributed along a third circular ring (531) with an inner diameter of R3, and a plurality of fourth circular holes (534) evenly distributed along a fourth circular ring (533) with an inner diameter of R4, wherein the inner diameter R3 of the third circular ring (531) is smaller than the inner diameter R4 of the fourth circular ring (533); the first circular hole (522) and the fourth circular hole (534) are connected through the inclined diversion channel (510), and the second circular hole (524) and the third circular hole (532) are connected through the inclined diversion channel (510).
3. The PP-R pipe extrusion die according to claim 2, characterized in that, The angle between the central axis of the inclined diversion channel (510) and the central axis of the inclined perforated plate (500) is 15°~20°.
4. The PP-R pipe extrusion die according to claim 2, characterized in that, The diameters of the first circular hole (522), the second circular hole (524), the third circular hole (532), and the fourth circular hole (534) are equal.
5. The PP-R pipe extrusion die according to any one of claims 2 to 4, characterized in that, An annular guide ring (540) is provided on the first end face (520) and / or the second end face (530). The annular guide ring (540) is disposed between the first ring (521) and the second ring (523) and / or between the third ring (531) and the fourth ring (533). The cross-section of the guide ring is triangular and protrudes from the first end face (520) and / or the second end face (530).
6. The PP-R pipe extrusion die according to any one of claims 2 to 4, characterized in that, The distance between the inclined hole plate (500) and the die assembly (300) is greater than the distance between the straight hole plate (600) and the die assembly (300).
7. The PP-R pipe extrusion die according to claim 6, characterized in that, The straight perforated plate (600) is provided with a fifth ring (620), and the horizontal flow channels (610) are evenly arranged in the fifth ring (620). The inner diameter R5 of the fifth ring (620) is smaller than the inner diameter R3 of the third ring (531), and the outer diameter R6 of the fifth ring (620) is larger than the outer diameter R7 of the fourth ring (533).
8. The PP-R pipe extrusion die according to claim 7, characterized in that, The horizontal diversion channel (610) has a circular, elliptical, or polygonal cross-sectional shape, and the total cross-sectional area of the horizontal diversion channel (610) is not less than the total cross-sectional area of the inclined diversion channel (510).
9. The PP-R pipe extrusion die according to claim 1, characterized in that, It also includes a spiral body (700) disposed inside the outer mold assembly (100), the outer wall of the spiral body (700) being provided with a spiral groove (710), and the preliminary plasticizing flow channel section (410) being disposed between the spiral groove (710) and the outer mold assembly (100).
10. The PP-R pipe extrusion die according to claim 9, characterized in that, It also includes a mold base (800), a shrink sleeve (910), and a shrink core (920). The die assembly (300) includes a die (310) and a die plate (320). One end of the outer mold assembly (100) is connected to the mold base (800), and the other end is connected to the shrink sleeve (910). The shrink core (920) is disposed inside the shrink sleeve (910). The spiral body (700) abuts against the inclined hole plate (500). The shrink sleeve (910) and the shrink core (920) abut against the straight hole plate (600). The shrink core (920) is provided with fastening bolts that pass through the straight hole plate (600), the inclined hole plate (500), and the spiral body (700). The shrink core (920) is connected to the mold core assembly (200). The die plate (320) is sleeved on the die (310) and connected to the shrink sleeve (910).