Double-layer composite pipe production extrusion components

Abstract

This utility model discloses an extrusion assembly for producing double-layer composite pipes, including a die head. A diverter die is mounted inside the die head via a support plate. A die core is mounted on the rear surface of the diverter die. A confluence die, sleeved outside the die core and located on one side of the support plate, is mounted inside the die head. An inner layer shaping die, sleeved outside the die core and located on one side of the confluence die, is also mounted inside the die head. A transition plate, mounted on the tail end of the die head, is fitted outside the inner layer shaping die. This utility model achieves this by using a wide transition plate between the inner and outer layer shaping dies. The die head and outer layer shaping die are heated in sections, while the inner layer shaping die is not heated externally. The inner layer material is extruded first for a certain period and distance, and after passing through a certain temperature difference, the inner layer pipe material has a smooth surface structure and a certain structural strength before the outer layer material is extruded externally. This ensures that the inner and outer composite surfaces are neat and flat during the extrusion of the double-layer composite pipe.

Description

Technical Field

[0001] This utility model relates to the field of double-layer composite pipe production technology, specifically to a double-layer composite pipe production extrusion assembly. Background Technology

[0002] Pipe extrusion dies are key components in the production of plastic pipes. Their working principle involves shaping molten plastic raw materials into pipes of the desired cross-sectional shape through a specially designed die. Precise temperature control and flow channel design ensure the dimensional accuracy and surface quality of the pipes. These dies are widely used in the production of pipes made of PVC, PE, PPR, and other materials. Among them, double-layer composite pipes combine the properties of two or more materials, exhibiting excellent performance and a wide range of applications.

[0003] The following two processes are commonly used in the extrusion of double-walled tubes:

[0004] 1. Co-extrusion process: When using an extruder, the material particles are heated and melted, and then extruded into the inner and outer layers of the tube through the double-layer flow channel in the die head. Under normal circumstances, the inner layer material enters the die head flow channel first and flows in the center of the flow channel, while the outer layer material flows around the outside of the inner layer material. The two layers of material merge at the end of the die head to form a double-layer structure.

[0005] 2. Composite die head process: In the process of using two extruders and a composite die head, the inner layer material extruder squeezes the inner layer material into the central flow channel of the composite die head, while the outer layer material extruder squeezes the outer layer material into the outer flow channel of the composite die head. The inner layer material enters the composite die head before the outer layer material and is compounded with the outer layer material inside the die head, and finally extruded to form a double-layer tube.

[0006] However, in existing technologies, whether it's the co-extrusion process or the composite die head process, the time and distance difference between the extrusion of the outer and inner layers is relatively small. Furthermore, both processes use a method of heating the entire die head, resulting in the inner layer material still being molten and not yet solidified when the outer layer material is extruded. At this time, the structural strength of the inner tube is very low. For double-layer composite tubes with different wall thicknesses of the inner and outer tubes, the different feeding pressures of the inner and outer layers can easily lead to unevenness of the inner and outer composite surfaces, affecting the mechanical properties and quality of the product. Therefore, there are shortcomings. Utility Model Content

[0007] To address the shortcomings of existing technologies, this utility model provides a double-layer composite pipe production extrusion assembly, which solves the problem that unevenness of the inner and outer composite surfaces during the extrusion of double-layer composite pipes with different inner and outer pipe wall thicknesses can easily affect the mechanical properties and quality of the product.

[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0009] A double-layer composite pipe production extrusion assembly includes a die head. A flow divider is installed inside the die head via a support plate. A die core is installed on the rear end surface of the flow divider. A flow merger is installed inside the die head, sleeved on the outside of the die core and located on one side of the support plate. An inner shaping die is also installed inside the die head, sleeved on the outside of the die core and located on one side of the flow merger.

[0010] The inner shaping mold is fitted with a transition plate that is snapped onto the tail end of the mold head. The mold core is also fitted with an outer shaping mold that is snapped onto the surface of the tail end of the inner shaping mold and snapped onto the tail end of the transition plate. An outer feed hole is provided on the outer shaping mold at the position corresponding to the front end of the mold cavity.

[0011] Preferably, the mold head, the support plate, and the flow divider are provided with water inlet holes that are connected internally and externally at corresponding positions, and the mold core and the flow divider are provided with direct current channels that are connected to the water inlet holes.

[0012] Preferably, the inner diameter of the tail end of the busbar mold is equal to the inner diameter of the inner shaping mold.

[0013] Preferably, the outer molding mold has a large diameter in the middle and small diameters at both ends, and the inner diameter of the front end of the outer molding mold is larger than the inner diameter of the inner molding mold.

[0014] Preferably, the width of the transition plate is at least half the width of the inner shaping mold.

[0015] Preferably, heating resistance wires are wound around the surface of the mold head, the middle surface of the outer shaping mold, and the tail end surface.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention increases the time and distance difference between the extrusion of the inner and outer layers of material by setting a wider transition plate in the inner and outer forming molds. Simultaneously, the die head and outer forming mold are heated in sections, while no heating is applied to the outside of the inner forming mold. The inner layer material is extruded first for a certain period and distance, and after passing through a certain temperature difference, the inner tube has achieved a smooth surface structure and sufficient structural strength before the outer layer material is extruded. This ensures that the inner and outer composite surfaces are neat and flat during the extrusion of the double-layer composite pipe, guaranteeing that the overall structural strength and mechanical properties meet expectations, thus improving product quality. This solves the problem in existing technologies where uneven inner and outer composite surfaces during the extrusion of double-layer composite pipes with different inner and outer tube wall thicknesses can negatively impact product mechanical properties and quality. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0019] In the diagram: 1. Die head; 2. Support plate; 3. Diverter mold; 4. Die core; 5. Merger mold; 6. Inner shaping mold; 7. Transition plate; 8. Outer shaping mold; 801. Cavity; 802. Mold cavity; 803. Outer feed hole; 9. Water inlet; 10. Direct flow channel; 11. Heating resistance wire. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] like Figure 1 As shown, this utility model provides a technical solution: a double-layer composite pipe production extrusion assembly, including a die head 1, a diverter 3 is installed inside the die head 1 by a bracket plate 2, water inlet holes 9 with internal and external communication are provided at corresponding positions of the die head 1, the bracket plate 2 and the diverter 3, a die core 4 is snapped onto the rear end surface of the diverter 3, and a direct flow channel 10 connected to the water inlet hole 9 is provided inside the die core 4 and the diverter 3;

[0022] The mold head 1 has a manifold mold 5 that is sleeved on the outside of the mold core 4 and located on one side of the support plate 2. The mold head 1 also has an inner layer shaping mold 6 that is sleeved on the outside of the mold core 4 and located on one side of the manifold mold 5. The inner diameter of the tail end of the manifold mold 5 is equal to the inner diameter of the inner layer shaping mold 6.

[0023] The inner shaping mold 6 is fitted with a transition plate 7 that is snapped onto the tail end of the mold head 1. The width of the transition plate 7 is at least half the width of the inner shaping mold 6. The mold core 4 is also fitted with an outer shaping mold 8 that is snapped onto the tail end surface of the inner shaping mold 6 and snapped onto the tail end of the transition plate 7. The outer shaping mold 8 has a large diameter in the middle and a small diameter at both ends of the mold cavity 802. The inner diameter of the front end of the outer shaping mold 8 is larger than the inner diameter of the inner shaping mold 6.

[0024] An outer feed hole 803 is provided on the outer shaping mold 8 at the position corresponding to the front mold cavity 802 of the cavity 801. Heating resistance wires 11 are wound on the surface of the mold head 1, the middle surface and the tail surface of the outer shaping mold 8.

[0025] Working principle:

[0026] After the inner layer material is heated and melted by the inner layer material extruder, it is extruded through the front end of the die head 1, and then passes through the support plate 2 and the manifold die 5 before being extruded from the inner layer shaping die 6 to form an inner tube. It continues to be extruded to the left, passing through the outer layer shaping die 8 and exiting. The heating resistance wire 11 outside the die head 1 heats and keeps the molten inner layer material warm. The inner layer shaping die 6 is not equipped with a heating resistance wire 11 for heating. Warm water is introduced through the water inlet 9 to slightly cool the inner tube, thus increasing its structural strength from a molten state. Then, the outer layer material passes through the outer layer material... After the material is heated and melted by the extruder, it is fed into the outer layer shaping mold 8 through the outer layer feed hole 803. The outer layer shaping mold 8 is equipped with a heating resistance wire 11 to heat and keep the outer layer molten material warm, so that it can smoothly cover the surface of the inner tube. The outer tube is formed by extrusion through the mold cavity 802 and the cavity 801, realizing the double-layer composite extrusion molding. By the time difference and distance difference between the extrusion of the inner layer material and the extrusion of the outer layer material, and the partitioned heating of the die head 1 and the outer layer shaping mold 8, the inner and outer composite surfaces are neat and flat during the extrusion of the double-layer composite tube.

[0027] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A double-layer composite pipe extrusion assembly, characterized in that: The device includes a mold head (1), a diversion mold (3) is installed inside the mold head (1) by a bracket plate (2), a mold core (4) is installed on the rear end surface of the diversion mold (3), a confluence mold (5) is installed inside the mold head (1) and sleeved on the outside of the mold core (4) and located on one side of the bracket plate (2), and an inner layer shaping mold (6) is also installed inside the mold head (1) and sleeved on the outside of the mold core (4) and located on one side of the confluence mold (5). The inner shaping mold (6) is fitted with a transition plate (7) that is snapped onto the tail end of the mold head (1). The mold core (4) is also fitted with an outer shaping mold (8) that is snapped onto the tail end surface of the inner shaping mold (6) and snapped onto the tail end of the transition plate (7). An outer feed hole (803) is provided on the outer shaping mold (8) at the position corresponding to the front mold cavity (802) of the cavity (801).

2. The extrusion assembly for producing double-layer composite tubes according to claim 1, characterized in that: The mold head (1), the support plate (2) and the diversion mold (3) are provided with water inlet holes (9) that are connected inside and outside. The mold core (4) and the diversion mold (3) are provided with direct current channels (10) that are connected to the water inlet holes (9).

3. The extrusion assembly for producing double-layer composite tubes according to claim 1, characterized in that: The inner diameter of the tail end of the busbar mold (5) is equal to the inner diameter of the inner shaping mold (6).

4. The extrusion assembly for producing double-layer composite tubes according to claim 1, characterized in that: The outer shaping mold (8) has a large diameter in the middle and a small diameter at both ends of the cavity (802), and the inner diameter of the front end of the outer shaping mold (802) is larger than the inner diameter of the inner shaping mold (6).

5. The extrusion assembly for producing double-layer composite tubes according to claim 1, characterized in that: The width of the transition plate (7) is at least half the width of the inner shaping mold (6).

6. The extrusion assembly for producing double-layer composite tubes according to claim 1, characterized in that: Heating resistance wires (11) are wound around the surface of the mold head (1), the middle surface of the outer shaping mold (8), and the tail end surface.

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