Extrusion forming die

Abstract

The extrusion forming die comprises an inner die body and an outer die body, the inner die body is inserted into the outer die body, a flow channel is formed between the outer wall of the inner die body and the inner wall of the outer die body, and the flow channel comprises a discharging channel; the inner die body comprises a core rod, the outer die body comprises a mouth die, the core rod is inserted into the mouth die, a discharging channel is formed between the outer wall of the core rod and the inner wall of the mouth die, the core rod is provided with a first air outlet channel, the first air outlet channel is communicated with the discharging channel and arranged in the circumferential direction of the outer wall of the core rod, and the outer die body is provided with a second air outlet channel which is communicated with the discharging channel. The second air outlet duct is arranged in the circumferential direction of the inner wall of the outer mold body. The extrusion molding die provided by the invention can improve the flowability of a material body.

Description

Technical Field

[0001] The present invention relates to the technical field of extrusion molds, and more specifically, to an extrusion mold. Background Art

[0002] For PE materials, sagging refers to the phenomenon that polymer materials sag and deform under their own gravity or external loads at high temperatures. For PE, the sagging characteristic is mainly manifested in the processing process. For example, during extrusion molding, the pipe is prone to sag and deform due to high-temperature softening, which affects the dimensional accuracy and appearance quality of the pipe. Currently, most pipe manufacturers resist sagging by adjusting the process temperature. The specific method is to lower the process temperature and the main machine speed to reduce shear heat, which results in poor melt fluidity, and then poor plasticization of the product, poor pipe performance, and low extrusion efficiency. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide an extrusion mold to improve the fluidity of the material.

[0004] To achieve the above purpose, the present invention adopts the following technical solution: An extrusion mold includes an inner mold body and an outer mold body. The inner mold body is inserted into the outer mold body, and a flow channel is formed between the outer wall of the inner mold body and the inner wall of the outer mold body. The flow channel includes a discharge channel; the inner mold body includes a mandrel, and the outer mold body includes a die. The mandrel is inserted into the die, and a discharge channel is formed between the outer wall of the mandrel and the inner wall of the die. The mandrel is provided with a first air outlet channel, and the first air outlet channel is communicated with the discharge channel. The first air outlet channel is arranged circumferentially along the outer wall of the mandrel. The outer mold body is provided with a second air outlet channel, and the second air outlet channel is communicated with the discharge channel. The second air outlet channel is arranged circumferentially along the inner wall of the outer mold body.

[0005] The present invention is further configured such that, along the direction perpendicular to the axial direction of the mandrel, the first air outlet channel and the second air outlet channel are arranged staggeredly.

[0006] The present invention is further configured such that the mandrel is provided with a first air inlet channel, the first air inlet channel is communicated with the first air outlet channel, the first air inlet channel is connected to an air source through a pipeline, the die is provided with a second air inlet channel, the second air inlet channel is communicated with the second air outlet channel, and the second air inlet channel is connected to an air source through a pipeline.

[0007] The present invention is further configured such that the flow channel is further provided with a feed channel, the feed channel can be filled with the material, the material flows in from the feed channel and flows out from the discharge channel, the opening at the connection between the first air outlet channel and the discharge channel faces the direction in which the material flows out of the discharge channel, and the opening at the connection between the second air outlet channel and the discharge channel faces the direction in which the material flows out of the discharge channel.

[0008] The present invention is further configured such that the inner mold body is provided with a through hole, the through hole is communicated with the first air inlet channel, and a heat insulation member is installed on the hole wall of the through hole.

[0009] The present invention is further configured such that the mandrel is provided with a first air chamber, the first air chamber communicates the first air inlet duct with the first air outlet duct, the die is provided with a second air chamber, and the second air chamber communicates the second air inlet duct with the second air outlet duct.

[0010] The present invention is further configured such that the inner mold body further includes a first mold body, the first mold body is inserted into the mandrel, and a first air chamber and a first air outlet duct are formed between the mandrel and the first mold body;

[0011] The present invention is further configured such that the outer mold body further includes a second mold body, the second mold body is inserted into the die, and a second air chamber and a second air outlet duct are formed between the die and the mold body.

[0012] The present invention is further configured such that the outer mold body is provided with a feed joint, and the feed joint is communicated with the runner.

[0013] In summary, the present invention has the following beneficial effects:

[0014] The gas discharged from the first air outlet duct and the second air outlet duct presses the material, so that an air gap is formed between the outer wall of the mandrel and the material, and an air gap is formed between the die and the material. Therefore, a separation state appears between the material and the outer wall surface of the mandrel and the inner wall surface of the die, reducing the flow resistance of the material to make up for the problem of poor fluidity of the material in the case of reducing the process temperature and the main machine speed to reduce the shear heat, as well as the associated problems of poor plasticization of the material, poor performance of the pipe, and low extrusion efficiency caused by poor fluidity of the material. Description of the Drawings

[0015] Figure 1 It is a cross-sectional view of the embodiment;

[0016] Figure 2 It is Figure 1 an enlarged view of part A in

[0017] Figure 3 It is a forming diagram of the first air gap and the second air gap in the embodiment.

[0018] Reference numerals: inner mold body 1, mandrel 11, first air chamber 111, first air inlet duct 112, first air outlet duct 113, first air gap 114, through hole 12, first mold body 13, outer mold body 2, die 21, second air chamber 211, second air inlet duct 212, second air outlet duct 213, second air gap 214, second mold body 22, runner 3, feed channel 31, discharge channel 32, feed joint 4, feed port 41, heat insulation member 5, spraying member 6, formed material 7. Detailed Embodiments

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] As Figures 1-3 shown, this embodiment discloses an extrusion molding die, which includes an inner die body 1 and an outer die body 2. The inner die body 1 is inserted into the outer die body 2, and a flow channel 3 is formed between the outer wall of the inner die body 1 and the inner wall of the outer die body 2. As Figure 1 shown, the cross-section of the flow channel 3 is annular. The flow channel 3 includes a feed channel 31 on the left side. The outer die body 2 is provided with a feed joint 4, and the feed joint 4 is provided with a feed port 41. The feed port 41 is communicated with the feed channel 31, and molten plastic material is injected into the feed channel 31 through the feed port 41 for extrusion molding.

[0021] As Figure 1 shown, the flow channel 3 further includes a discharge channel 32 on the right side. The feed channel 31 is connected to an extruder, and the material flows into the discharge channel 32 from the feed channel 31 and then flows out.

[0022] As Figure 1 、 Figure 2 shown, the inner die body 1 includes a mandrel 11 at the right end, and the outer die body 2 includes a die head 21 at the right end. The mandrel 11 is inserted into the die head 21, and a discharge channel 32 is formed between the outer wall of the mandrel 11 and the inner wall of the die head 21. The formed material 7 is formed after the material is extruded from the discharge channel 32.

[0023] As Figure 2As shown in the figure, the inner die body 1 further includes a first die body 13 located on the left side of the mandrel 11. The first die body 13 is inserted into the mandrel 11, and an air chamber 111 and an air outlet duct 113 are formed between the mandrel 11 and the first die body 13. Both the air chamber 111 and the air outlet duct 113 are annular. The air outlet duct 113 is communicated with the discharge channel 32, and the air chamber 111 is located on the side of the air outlet duct 113 away from the discharge channel 32. The mandrel 11 is further provided with an air inlet duct 112, and the air inlet duct 112 is located on the side of the air chamber 111 away from the air chamber 111. The air inlet duct 112 is externally connected to the air source generated by the high-pressure gas compressor. The air source gas is high-temperature gas to prevent excessive heat loss of the material. The air inlet duct 112 is a hole formed along the radial direction of the mandrel 11. Since the air in the air inlet duct 112 only enters in one direction, if the air inlet duct 112 is directly communicated with the air outlet duct 113, it will cause serious uneven air pressure in the circumferential direction of the air outlet duct 113. Therefore, an air chamber 111 is provided between the air inlet duct 112 and the air outlet duct 113. The air chamber 111 plays a role in storing air and buffering the air flowing from the air inlet duct 112 to the air outlet duct 113, so as to improve the uniformity of the air pressure in the circumferential direction of the air outlet duct 113.

[0024] As Figure 2 shown in the figure, the outer die body 2 further includes a second die body 22 located on the left side of the die orifice 21. The second die body 22 is inserted into the die orifice 21, and an air chamber 211 and an air outlet duct 213 are formed between the die orifice 21 and the die body 22. Both the air chamber 211 and the air outlet duct 213 are annular. The air outlet duct 213 is communicated with the discharge channel 32, and the air chamber 211 is located on the side of the air outlet duct 213 away from the discharge channel 32. The die orifice 21 is further provided with an air inlet duct 212, and the air inlet duct 212 is located on the side of the air chamber 211 away from the air outlet duct 213. The air inlet duct 212 is externally connected to the air source generated by the high-pressure gas compressor. The setting effect of the air chamber 211 is the same as that of the air chamber 111.

[0025] The air outlet duct 113 is arranged along the circumferential direction of the outer wall of the mandrel 11, and the air outlet duct 213 is arranged along the circumferential direction of the inner wall of the outer die body 2. The opening of the connection between the air outlet duct 113 and the discharge channel 32 faces the direction in which the material flows out of the discharge channel 32, and the opening of the connection between the air outlet duct 213 and the discharge channel 32 faces the direction in which the material flows out of the discharge channel 32. As Figure 3As shown in the figure, as the material in the discharge channel 32 flows, the gas flowing out from the first air outlet channel 113 and the second air outlet channel 213 squeezes the material, forming an air gap 114 between the outer wall of the mandrel 11 and the material, and an air gap 214 between the material of the die head 21. Therefore, a separation state appears between the material and the outer wall surface of the mandrel 11 and the inner wall surface of the die head 21, reducing the flow resistance of the material. To make up for the problem of poor fluidity of the material when the process temperature is lowered and the main machine speed is lowered to reduce shear heat, as well as the associated problems of poor plasticization of the material, poor performance of the pipe, and low extrusion efficiency caused by the poor fluidity of the material.

[0026] The air flow exits from the right end of the discharge channel 32, and at the same time plays a role in promoting and assisting the material in the discharge channel 32.

[0027] As Figure 2 As shown in the figure, along the direction perpendicular to the axial direction of the mandrel 11, the first air outlet channel 113 and the second air outlet channel 213 are arranged staggeredly left and right to avoid the phenomenon of interrupted discharge caused by excessive air flow resistance of the material on the same cross section. At the same time, in the initial stage, the air flows of the first air outlet channel 113 and the second air outlet channel 213 can play a role in blocking the flow of the front-section material to reduce the generation of waste of the front-section material.

[0028] The inner mold body 1 is provided with a through hole 12, the through hole 12 axially penetrates the inner mold body 1, the through hole 12 is communicated with the first air inlet channel 112, and a heat insulation component 5 is installed on the hole wall of the through hole 12. A cooling pipe is arranged in the through hole 12, the cooling pipe is connected to a spraying component 6, and the spraying component 6 sprays cooling water on the molding material 7 to quickly cool it, so as to solve the defect problem that the current molding material 7 only cools its outer wall, with higher cooling efficiency and can reduce the sagging phenomenon of the molding material 7 (sagging refers to the drooping deformation phenomenon of polymer materials under their own gravity or external loads under high temperature conditions. The sagging characteristic is mainly manifested in the process of processing, such as in extrusion molding, the pipe is prone to drooping deformation due to high temperature softening, affecting the dimensional accuracy and appearance quality of the pipe). At the same time, cold air is introduced into the through hole 12 through a cold air blower to improve the cooling effect of the inner wall of the molding material 7, and the heat insulation component 5 is heat insulation cotton, which plays a role in temperature isolation.

[0029] The above is only the preferred implementation manner of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An extrusion molding die, characterized in that, It includes an inner die body (1) and an outer die body (2). The inner die body (1) is inserted into the outer die body (2), and a flow channel (3) is formed between the outer wall of the inner die body (1) and the inner wall of the outer die body (2). The flow channel (3) includes a discharge channel (32). The inner die body (1) includes a mandrel (11), and the outer die body (2) includes a die orifice (21). The mandrel (11) is inserted into the die orifice (21), and the discharge channel (32) is formed between the outer wall of the mandrel (11) and the inner wall of the die orifice (21). The mandrel (11) is provided with a first air outlet duct (113), and the first air outlet duct (113) communicates with the discharge channel (32). The first air outlet duct (113) is arranged circumferentially along the outer wall of the mandrel (11). The outer die body (2) is provided with a second air outlet duct (213), and the second air outlet duct (213) communicates with the discharge channel (32). The second air outlet duct (213) is arranged circumferentially along the inner wall of the outer die body (2).

2. The extrusion molding die according to claim 1, characterized in that, Along the direction perpendicular to the axial direction of the mandrel (11), the first air outlet duct (113) and the second air outlet duct (213) are arranged staggeredly.

3. An extrusion molding die according to claim 1, characterized in that, The mandrel (11) is provided with a first air inlet duct (112), and the first air inlet duct (112) communicates with the first air outlet duct (113). The first air inlet duct (112) is connected to an air source through a pipeline. The die orifice (21) is provided with a second air inlet duct (212), and the second air inlet duct (212) communicates with the second air outlet duct (213). The second air inlet duct (212) is connected to an air source through a pipeline.

4. An extrusion molding die according to claim 1, characterized in that, The flow channel (3) is further provided with a feed channel (31), and a material body can be introduced into the feed channel (31). The material body flows in from the feed channel (31) and flows out from the discharge channel (32). The opening at the connection between the first air outlet duct (113) and the discharge channel (32) faces the direction in which the material body flows out of the discharge channel (32), and the opening at the connection between the second air outlet duct (213) and the discharge channel (32) faces the direction in which the material body flows out of the discharge channel (32).

5. An extrusion molding die according to claim 3, characterized in that, The inner die body (1) is provided with a through hole (12), and the through hole (12) communicates with the first air inlet duct (112). A heat insulation component (5) is installed on the hole wall of the through hole (12).

6. An extrusion molding die according to claim 3, wherein The mandrel (11) is provided with a first air chamber (111), and the first air chamber (111) communicates the first air inlet duct (112) with the first air outlet duct (113). The die orifice (21) is provided with a second air chamber (211), and the second air chamber (211) communicates the second air inlet duct (212) with the second air outlet duct (213).

7. An extrusion molding die according to claim 6, characterized in that, The inner die body (1) further includes a first die part (13), and the first die part (13) is inserted into the mandrel (11). The first air chamber (111) and the first air outlet duct (113) are formed between the mandrel (11) and the first die part (13). The outer mold body (2) further includes a second mold body (22), the second mold body (22) is inserted into the die head (21), and an air chamber two (211) and an air outlet duct two (213) are formed between the die head (21) and the second mold body (22).

8. The extrusion molding die according to claim 1, wherein, The outer mold body (2) is provided with a feed joint (4), and the feed joint (4) is communicated with the flow channel (3).

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