Co-extrusion ring for pipe extrusion

Abstract

The utility model relates to the technical field of plastic pipe production, and particularly discloses a co-extrusion ring for pipe extrusion, which comprises a co-extrusion ring body, the co-extrusion ring body is provided with a feeding runner, a coarse co-extrusion groove and a fine co-extrusion groove, the coarse co-extrusion groove and the fine co-extrusion groove are both communicated with the feeding runner, the fine co-extrusion groove is symmetrically arranged relative to the coarse co-extrusion groove, and the coarse co-extrusion groove is communicated with the fine co-extrusion groove. And the feeding runners are symmetrically arranged relative to the coarse co-extrusion groove. The co-extrusion ring structure is used for solving the problem that two thin co-extrusion strips and one thick co-extrusion strip extruded by a co-extrusion ring structure in the prior art are uneven in thickness.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic pipe production, in particular to a co-extrusion ring for pipe extrusion. Background Art

[0002] At present, the common form of co-extruded strips is four co-extruded strips evenly distributed on the outer surface of the pipe, such as the co-extruded strips extruded by the "A co-extruded strip mold structure for high-speed production of PPR pipes" with patent announcement number CN211221977U. On some pipes, it is necessary to extrude two thin and one thick co-extruded strips, such as extruding two thin and one thick co-extruded strips, a total of three co-extruded strips, on the C-PPR pipe, where the thick co-extruded strip is used for coding information spraying. When extruding this type of co-extruded strip, it is necessary to ensure that the three co-extruded strips are extruded at the same time, and the extrusion width size is stable.

[0003] The prior art adopts a "co-extrusion ring structure for C-PPR pipes" with patent announcement number CN219634483U. The co-extrusion ring structure can realize the extrusion of three co-extrusion strips, two thin and one thick, on the pipe. Specifically, after feeding from the feeding channel of the co-extrusion ring, the raw material enters a nearly 360° annular flow channel, and then the raw material moves to two thin co-extrusion grooves and a thick co-extrusion groove, thereby extruding three co-extrusion strips, two thin and one thick, on the pipe. However, the existing method has the following problems:

[0004] 1. The thickness of the three co-extruded strips is uneven, resulting in a significant difference in the width of the two thin co-extruded strips. The size of the thick co-extruded strip is small, the coding position is difficult to adjust, and it is easy to spray outside the co-extruded strip, resulting in waste.

[0005] 2. The annular groove for balancing the flow channel opened on the back of the existing co-extrusion ring mold is prone to leakage after long-term operation, resulting in serious flow channel lines on the outer surface of the pipe. Utility Model Content

[0006] The utility model aims to provide a co-extrusion ring for pipe extrusion, so as to solve the problem of uneven thickness of thin co-extrusion strips in the co-extrusion ring structure of the prior art when extruding two thin and one thick co-extrusion strips.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A coextrusion ring for pipe extrusion comprises a coextrusion ring body, on which a feed flow channel, a coarse coextrusion groove and a fine coextrusion groove are arranged. The coarse coextrusion groove and the fine coextrusion groove are both connected to the feed flow channel, the fine coextrusion groove is symmetrically arranged with respect to the coarse coextrusion groove, and the feed flow channel is symmetrically arranged with respect to the coarse coextrusion groove.

[0009] The principle and advantage of this scheme are: this scheme arranges the fine co-extrusion groove and the feed flow channel symmetrically about the coarse co-extrusion groove, so that the raw material on the feed flow channel enters the coarse co-extrusion groove with a wider width on the one hand, and flows to the fine co-extrusion grooves on both sides of the coarse co-extrusion groove on the other hand, ensuring that the flow rate of the fine co-extrusion grooves on both sides is the same when discharging materials, thereby ensuring that the width of the extruded fine co-extrusion strips is consistent. When the width of the fine co-extrusion strips on both sides is consistent and the extrusion pressure is the same, the width stability of the coarse co-extrusion strips extruded by the coarse co-extrusion groove can also be guaranteed, thereby solving the problem in the prior art that the fine co-extrusion grooves have different flow rates due to different distances from the feed inlet, which ultimately leads to uneven width of the fine co-extrusion strips.

[0010] Preferably, as an improvement, the feed flow channel is annular, and both ends of the feed flow channel are at a distance from adjacent fine co-extrusion grooves, so that a buffer zone is formed in the feed flow channel to balance the pressure.

[0011] Preferably, as an improvement, the depth of the feed channel is greater than the depth of the co-extrusion groove, and the co-extrusion ring body does not have a groove on the back that is connected to the feed channel, ensuring that the channel pressure can be balanced through the annular feed channel. There is no need to open an annular groove on the back of the co-extrusion ring body, thereby avoiding the problem of material leakage on the back of the co-extrusion ring mold.

[0012] Preferably, as an improvement, the length of the annular feed flow channel is 150°-210°.

[0013] Preferably, as an improvement, the centers of the fine co-extrusion groove and the coarse co-extrusion groove form an angle of 20°-30°. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a front view of an embodiment of the utility model.

[0015] Figure 2 It is a rear view of an embodiment of the utility model.

[0016] Figure 3 It is a right sectional view of an embodiment of the utility model. DETAILED DESCRIPTION

[0017] The following is further described in detail through specific implementation methods:

[0018] The reference numerals in the drawings of the specification include: a co-extrusion ring body 1 , a coarse co-extrusion groove 2 , a fine co-extrusion groove 3 , a main channel 4 , and a feed hole 5 .

[0019] Example

[0020] Combination Figures 1 to 3A co-extrusion ring for pipe extrusion comprises a co-extrusion ring body 1, the co-extrusion ring body 1 is provided with a feed channel, a coarse co-extrusion groove 2 and a fine co-extrusion groove 3, the feed channel comprises a main channel 4 and a feed hole 5 which are interconnected, the feed hole 5 is symmetrical about the main channel 4, the main channel 4, the coarse co-extrusion groove 2 and the fine co-extrusion groove 3 are all located on the front side of the co-extrusion ring body 1, the coarse co-extrusion groove 2 and the fine co-extrusion groove 3 are all connected with the main channel 4, and the two fine co-extrusion grooves 3 are symmetrically arranged about the coarse co-extrusion groove 2, and the feed channel is also symmetrically arranged about the coarse co-extrusion groove 2.

[0021] The main channel 4 of the feed channel is annular, and the length of the main channel 4 is 150°-210°. In this embodiment, the length of the main channel 4 is 180°, and the main channel 4 is concentric with the pipe; both ends of the annular length feed channel are distanced from the adjacent fine co-extrusion groove 3, and the center of the fine co-extrusion groove 3 and the center of the coarse co-extrusion groove 2 are at an angle of 20°-30°. In this embodiment, the angle between the center line of the fine co-extrusion groove 3 and the center line of the coarse co-extrusion groove 2 is 25°.

[0022] The depth of the main channel 4 is greater than the depth of the coarse co-extrusion groove 2 and the fine co-extrusion groove 3. The co-extrusion ring body 1 has no annular groove on the back thereof which is connected with the feed port.

[0023] The specific process of this embodiment is as follows:

[0024] When this embodiment is adopted, the molten raw material enters from the feed hole 5 and then flows to the coarse co-extrusion groove 2 and the fine co-extrusion groove 3 through the main channel 4. Since the feed hole 5 is located at the center line of the coarse co-extrusion groove 2, the main channel 4 and the fine co-extrusion groove 3 are symmetrical about the coarse co-extrusion groove 2. Therefore, the fine co-extrusion grooves 3 on both sides extrude the fine co-extrusion grooves 3 at the same flow rate, ensuring the width consistency of the fine co-extrusion strips on both sides, and also ensuring the extrusion stability and width consistency of the coarse co-extrusion strips, solving the problems of uneven width of the fine co-extrusion strips and difficult to ensure the width of the coarse co-extrusion strips.

[0025] In addition, this embodiment eliminates the annular groove on the back side and sets the depth of the groove and the length of the main channel 4 to 180°, thereby ensuring that the improved co-extrusion ring has a sufficiently long flow channel for pressure relief, and at the same time does not cause the problem of raw material leakage due to extrusion from the annular groove on the back side.

[0026] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A co-extrusion ring for pipe extrusion, comprising a co-extrusion ring body, on which a feed channel, a coarse co-extrusion groove and a fine co-extrusion groove are provided, wherein the coarse co-extrusion groove and the fine co-extrusion groove are both connected to the feed channel, characterized in that: The fine co-extrusion groove is symmetrically arranged with respect to the rough co-extrusion groove, and the feed flow channel is symmetrically arranged with respect to the rough co-extrusion groove.

2. A co-extrusion ring for pipe extrusion according to claim 1, characterized in that: The feed flow channel is annular, and both ends of the feed flow channel are spaced apart from adjacent fine co-extrusion grooves.

3. A co-extrusion ring for pipe extrusion according to claim 2, characterized in that: The depth of the feed channel is greater than the depth of the co-extrusion groove, and the co-extrusion ring body has no groove on the back thereof that is in communication with the feed channel.

4. A co-extrusion ring for pipe extrusion according to any one of claims 1 to 3, characterized in that: The centers of the fine co-extrusion groove and the coarse co-extrusion groove form an angle of 20°-30°.

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