An extrusion die

Abstract

The application belongs to the technical field of mold manufacturing, and particularly relates to an extrusion mold, which comprises a cover plate and a base, and further comprises an inner mold sleeve made of PTFE material, the base is provided with a channel with open ends, the base is coaxially provided with an expansion port at one end of the channel, the inner mold sleeve is coaxially installed in the expansion port, the inner diameter of the inner mold sleeve is equal to the inner diameter of the channel, the cover plate is coaxially covered on the expansion port, the cover plate is located on one side of the bottom of the inner mold sleeve away from the expansion port, the cover plate is provided with a through hole, and the inner diameter of the through hole is greater than or equal to the inner diameter of the inner mold sleeve; the inner mold sleeve made of PTFE material is installed at the discharge port of the extrusion mold, so that the friction coefficient of the discharge port is reduced, the surface of the extruded polyethylene is smooth, and the problem that the polyethylene is mostly extruded by using a common steel material mold at present, so that the surface of the extruded polyethylene is rough and the discharge port of the mold has precipitates is solved.

Description

Technical Field

[0001] This application belongs to the field of mold manufacturing technology, specifically an extrusion mold. Background Technology

[0002] The power cable industry is currently undergoing technological upgrades and experiencing a surge in demand. Conventional medium and low voltage cables are in high demand in fields such as energy and power, construction, industrial manufacturing, and transportation. Especially in the era of economic globalization, having high-quality products means having access to the international market. Promoting high-quality products can accelerate the company's globalization strategy and help the country move from a major cable manufacturing country to a leading cable manufacturing country.

[0003] Polyethylene is the most abundant plastic material in power cables, and its processing technology is one of the most critical technologies. Currently, most polyethylene extrusion processes in the industry use ordinary steel molds, which have problems such as rough surfaces and exudates at the die opening. Utility Model Content

[0004] The purpose of this application is to address the shortcomings of existing technologies by installing an inner mold sleeve made of PTFE material at the discharge port of the extrusion mold, thereby reducing the friction coefficient at the discharge port and making the surface of the extruded polyethylene smooth. This solves the problem that most polyethylene extrusion molds in the industry are made of ordinary steel, which results in a rough surface of the extruded polyethylene and exudates at the mold discharge port.

[0005] To achieve the above objectives, the following technical solution is adopted: An extrusion mold includes a cover plate, a base, and an inner mold sleeve made of PTFE material. The base has a channel with openings at both ends. An expansion port is coaxially provided on one end of the channel on the base. The inner mold sleeve is coaxially installed in the expansion port. The inner diameter of the inner mold sleeve is equal to the inner diameter of the channel. The cover plate coaxially covers the expansion port. The cover plate is located on the side of the inner mold sleeve facing away from the bottom of the expansion port. The cover plate has a through hole. The inner diameter of the through hole is greater than or equal to the inner diameter of the inner mold sleeve.

[0006] Preferably, the inner mold sleeve has a protrusion coaxially provided on the side opposite to the bottom of the expansion port, and the inner diameter of the cover plate is greater than or equal to the outer diameter of the protrusion.

[0007] Preferably, the inner diameter of the cover plate is equal to the outer diameter of the protrusion.

[0008] Preferably, the outer circumferential surface of the cover plate is provided with an external thread, and the expansion port is provided with an internal thread that mates with the external thread.

[0009] Preferably, the cover plate has a plurality of mounting holes around the through hole, the expansion port has a plurality of screw holes axially arranged around the channel, the inner mold sleeve has a plurality of transition holes around the protrusion, and the bolt passes through the mounting holes and the transition holes from the outside of the cover plate and then engages with the screw holes.

[0010] Preferably, the thickness of the center of the cover plate is equal to the length of the protrusion.

[0011] Preferably, the side of the cover plate facing away from the expansion opening is an arc-shaped surface that protrudes from the center of the expansion opening.

[0012] Compared with the prior art, the beneficial effects of this application are: 1. This application uses an inner mold sleeve made of PTFE material installed at the discharge port of the extrusion mold, which reduces the friction coefficient of the discharge port and makes the surface of the polyethylene smooth after extrusion. This solves the problem that most polyethylene extrusion molds in the industry are made of ordinary steel material, which results in rough surface of the polyethylene after extrusion and exudates at the discharge port of the mold.

[0013] 2. When extruding polyethylene, the bearing area of ​​the original mold is replaced with an inner mold sleeve made of PTFE material. The inner mold sleeve made in this way has better chemical resistance; the temperature resistance can reach 260℃, and it can reach 300℃ for a short period of time; its non-stickiness makes polyethylene less likely to stick to the die orifice, thereby reducing the carry-out of exudates. Attached Figure Description

[0014] Figure 1 This is an exploded view showing that the cover plate in this application is bolted together. Figure 2 This is an exploded view showing the threaded locking mechanism of the cover plate in this application; Figure 3 This is a schematic diagram of the structure in this application where the cover plate is bolted together.

[0015] The components are: 1. cover plate; 2. base; 3. inner mold sleeve; 4. expansion port; 5. protrusion; 6. through hole; 7. mounting hole; 8. transition hole; 9. screw hole; 10. bolt. Detailed Implementation

[0016] Reference Figure 1 - Figure 3An extrusion mold includes a cover plate 1, a base 2, and an inner mold sleeve 3. The inner mold sleeve 3 is made of PTFE material. The base 2 has a channel with openings at both ends. An expansion port 4 is coaxially provided on one end of the channel on the base 2. The inner mold sleeve 3 is coaxially installed on the expansion port 4. The inner diameter of the inner mold sleeve 3 is equal to the inner diameter of the channel. The cover plate 1 coaxially covers the expansion port 4. The cover plate 1 is located on the side of the inner mold sleeve 3 facing away from the bottom of the expansion port 4. The cover plate 1 has a through hole 6. The inner diameter of the through hole 6 is greater than or equal to the inner diameter of the inner mold sleeve 3.

[0017] In this embodiment, during use, polyethylene enters the entire extrusion mold from the end of the base 2 facing away from the cover plate 1, and then exits from the inner mold sleeve 3 made of PTFE material. Due to the low coefficient of friction of the inner mold sleeve 3, the surface of the polyethylene after extrusion is smoother. The expansion port 4 is provided for installing the inner mold sleeve 3, and the through hole 6 provided on the cover plate 1 is to prevent the extruded polyethylene from contacting the inner wall of the through hole 6.

[0018] As a preferred embodiment, the inner mold sleeve 3 is coaxially provided with a protrusion 5 on the side facing away from the bottom of the expansion port 4, and the inner diameter of the cover plate 1 is greater than or equal to the outer diameter of the protrusion 5. This protrusion 5 further prevents the extruded polyethylene from contacting the inner wall of the through hole 6. Simultaneously, the protrusion 5 facilitates insertion into the through hole 6 for positioning when the inner mold sleeve 3 and the cover plate 1 are combined.

[0019] As a preferred embodiment, the inner diameter of the cover plate 1 is equal to the outer diameter of the protrusion 5. This arrangement allows the cover plate 1 to be more securely assembled with the inner mold sleeve 3 after it is closed.

[0020] As a preferred embodiment, the outer circumferential surface of the cover plate 1 is provided with an external thread, and the expansion port 4 is provided with an internal thread that mates with the external thread. With this configuration, the cover plate 1 locks the inner mold sleeve 3 onto the base 2 by engaging the internal thread on the expansion port 4 with the internal thread.

[0021] As a preferred embodiment, the cover plate 1 has several mounting holes 7 around the through hole 6, the expansion port 4 has several threaded holes axially arranged around the channel, and the inner mold sleeve 3 has several transition holes 8 around the protrusion 5. The bolt 10 passes through the mounting holes 7 and the transition holes 8 from the outside of the cover plate 1 and then engages with the threaded holes 9. This arrangement of mounting holes 7 and transition holes 8 allows the bolt 10 to lock the cover plate 1 and the inner mold sleeve 3 onto the base 2, and also facilitates disassembly when the inner mold sleeve 3 needs to be replaced.

[0022] As a preferred embodiment, the thickness of the center of the cover plate 1 is equal to the length of the protrusion 5. This arrangement ensures that the protrusion 5 does not extend beyond the top of the cover plate 1, thereby preventing damage to the protrusion 5.

[0023] As a preferred embodiment, the side of the cover plate 1 facing away from the expansion port 4 is an arc-shaped surface that protrudes centrally from the expansion port. This arrangement facilitates the observation of the length of the extruded polyethylene.

[0024] As a preferred method, the black PTFE used to make the inner mold sleeve 3 is ordinary PTFE modified with carbon black, which increases wear resistance and extends the service life of PTFE while retaining the excellent properties of PTFE.

Claims

1. An extrusion mold, comprising a cover plate (1) and a base (2), characterized in that, It also includes an inner mold sleeve (3), which is made of PTFE material. The base (2) has a channel with openings at both ends. The base (2) has an expansion port (4) coaxially provided at one end of the channel. The inner mold sleeve (3) is coaxially installed in the expansion port (4). The inner diameter of the inner mold sleeve (3) is equal to the inner diameter of the channel. The cover plate (1) is coaxially covered in the expansion port (4). The cover plate (1) is located on the side of the inner mold sleeve (3) facing away from the bottom of the expansion port (4). The cover plate (1) has a through hole (6). The inner diameter of the through hole (6) is greater than or equal to the inner diameter of the inner mold sleeve (3).

2. An extrusion mold according to claim 1, characterized in that, The inner mold sleeve (3) has a protrusion (5) coaxially arranged on the side facing away from the bottom of the expansion port (4), and the inner diameter of the cover plate (1) is greater than or equal to the outer diameter of the protrusion (5).

3. An extrusion mold according to claim 2, characterized in that, The inner diameter of the cover plate (1) is equal to the outer diameter of the protrusion (5).

4. An extrusion mold according to claim 1, characterized in that, The outer circumferential surface of the cover plate (1) is provided with an external thread, and the expansion port (4) is provided with an internal thread that mates with the external thread.

5. An extrusion mold according to claim 2, characterized in that, The cover plate (1) has several mounting holes (7) around the through hole (6), the expansion port (4) has several screw holes axially around the channel, the inner mold sleeve (3) has several transition holes (8) around the protrusion (5), and the bolt (10) passes through the mounting hole (7) and the transition hole (8) from the outside of the cover plate (1) and then engages with the screw hole (9).

6. An extrusion mold according to claim 3, characterized in that, The thickness of the center of the cover plate (1) is equal to the length of the protrusion.

7. An extrusion mold according to claim 6, characterized in that, The side of the cover plate (1) facing away from the expansion port (4) is an arc-shaped surface that protrudes from the center of the expansion port.

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