CN114083776A

CN114083776A - Combined coating die for krah pipe

Info

Publication number: CN114083776A
Application number: CN202111565811.2A
Authority: CN
Inventors: 马鑫; 陈晓梅; 陈文彬; 彭伏弟; 林知; 曹静; 李文权; 高洁
Original assignee: Fujian Aton Advanced Materials Technology Co ltd
Current assignee: Fujian Aton Advanced Materials Technology Co ltd
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2022-02-25

Abstract

The invention provides a combined coating die for a Clar pipe, which relates to the technical field of pipeline production equipment and comprises a neck mold and a pipe core.

Description

Combined coating die for krah pipe

Technical Field

The invention belongs to the technical field of pipeline production equipment, and particularly relates to a combined coating die for a carat pipe.

Background

The hot winding forming High Density Polyethylene (HDPE) winding structure wall pipe is also called a Krah pipe, is one of the main pipes for municipal drainage and sewage discharge, adopts the hot winding forming technology to spirally wind the pipe wall and an outer rib at the same time, the pipe wall is formed by overlapping HDPE strips, the outer rib consists of an inner lining pipe (PP single-wall corrugated pipe) and an O-shaped HDPE belt layer, the outer rib is wound outside the pipe wall, and the outer rib and the pipe wall form a structure wall in a hot fitting mode.

Usually, the bush front end is straight hollow circular cylinder form, and the length design of straight section can influence the extrusion quality, and straight partial length generally is 2-6 times of bush internal diameter, and the internal diameter is little, gets great multiple, otherwise then is opposite, but straight partial length is too big, can make extrusion resistance too big again, causes to extrude the surface roughness.

In the coating process of the lining pipe, the O-shaped HDPE belt layer is easy to turn inwards when being demoulded, so that the coating effect is poor, the shrinkage trace is obvious, the corrugation phenomenon of the surface of the outer rib is generated, and the attractiveness and the performance are influenced. The inner lining pipe is coated with the O-shaped HDPE belt layer through the coating die, the key technical key points of the pipe are one of the key technical key points, the neck mold design of the coating die is one of the main factors influencing the coating quality, and the coating effect directly influences the appearance quality and the one-time qualification rate of the product.

Disclosure of Invention

The invention aims to provide a combined coating die for a Krah pipe, which can uniformly coat an O-shaped HDPE belt layer on the outer side of an inner liner pipe, so that the coating appearance is smooth, and the corrugation phenomenon on the surface of an outer rib is improved.

In order to achieve the purpose of the invention, the invention adopts the following technical scheme.

A combined cladding die for a Krah pipe comprises a die 1 and a pipe core 2, wherein the die 1 comprises a threaded joint 11, a die front end 12, a die rear end 13, a transition section 14 and a contraction section 15, the pipe core 2 comprises a clamping module 21, a clamping groove 22 and a blocking block 23, the clamping groove 22 is located in the middle of the clamping module 21, the pipe core 2 is in a hollow cylinder shape with three outer diameters and is sleeved on the die front end, an O-shaped HDPE belt layer 3 is formed in a shaping mode through an O-shaped gap between the die 1 and the pipe core 2, and a PP single-wall corrugated pipe 4 penetrates through the inner side of the die rear end 13 to the inner side of the die front end 12.

Furthermore, the ratio of the inner diameter of the front end 12 of the die to the outer diameter of the PP single-wall corrugated pipe 4 is (1.01-1.03): 1.

Further, the difference between the inner diameter of the core 2 and the outer diameter of the die tip 12 is equal to one half of the thickness of the "O" HDPE tape layer 3.

Further, the "O" HDPE tape layer 3 is extruded from the HDPE plastic melt through an extruder, and flows in the direction from the die rear end 13 to the die front end 12 in the "O" shaped gap formed between the die 1 and the tube core 2.

Further, the threaded joint 11 is mounted on the rear interface sleeve in a threaded manner.

Furthermore, the clamping groove 22 is located in the middle of the clamping module 21, and is in a concave ring shape for clamping the tube core on the outer mold body.

Furthermore, the rear end 13 of the neck mold is in tapered transition with the front end 12 of the neck mold, wherein the transition section 14 is in arc-shaped smooth curved surface transition.

Further, the front end 12 of the neck ring mold is an elongated straight cylinder, and the ratio of the length of the front end 12 of the neck ring mold to the inner diameter of the neck ring mold 1 is 1: (3-7), the purpose of lengthening is: the material flow resistance can be increased, and the O-shaped HDPE belt layer 3 is compact and compact.

Furthermore, the most front edge of the front end 12 of the neck ring mold is provided with a contraction section 15, the outer diameter of the front end 12 of the neck ring mold is reduced through the contraction section 15, and the length ratio of the contraction section 15 to the front end 12 of the neck ring mold is 1: (4-8) for the purpose of: the joint part of the O-shaped HDPE belt layer 3 and the PP single-wall corrugated pipe 4 forms transition, so that the O-shaped HDPE belt layer 3 is prevented from being turned inwards or forming a corrugated shape due to overlarge vertical gap between the O-shaped HDPE belt layer 3 and the PP single-wall corrugated pipe 4, and the appearance quality of a product is improved.

Furthermore, the right edge surface of the blocking block 23 and the circular contour surface of the initial diameter reduction of the transition section 15 are in the same plane in the vertical direction.

Drawings

FIG. 1 is a cross-sectional view of a mold of the present invention.

FIG. 2 is a cross-sectional partial view of the mold of the present invention.

The items in the figure are respectively: the corrugated pipe comprises a 1-die, 11-thread joints, 12-die front ends, 13-die rear ends, 14 transition sections, 15 contraction sections, 2-die, 21 clamping modules, 22 clamping grooves, 23 sealing blocks, 3 'O' -shaped HDPE belt layers and 4PP single-wall corrugated pipes.

Detailed Description

The present invention is described in detail below with reference to the attached drawings.

The combined cladding die for the krah pipe as shown in the attached figures 1 and 2 comprises a neck die 1, wherein the rearmost end of the neck die 1 is provided with a threaded joint 11, the threaded joint 11 is used for fixing the neck die 1, the neck die 1 is provided with a neck die rear end 13 and a neck die front end 12, the outer diameter of the neck die rear end 13 is larger than that of the neck die front end 12, the neck die rear end 13 and the neck die front end 12 are in tapered transition, the tapered transition region comprises a transition section 14, the transition section 14 is arc-shaped and can increase smoothness of material flow, the neck die front end 12 comprises a contraction section 15, the outer diameter of the contraction section 15 is transited to the outer diameter of a PP single-wall corrugated pipe 4, and transition in such a way can avoid that an O-shaped HDPE belt layer 3 is turned inwards or corrugated due to overlarge vertical clearance between the O-shaped HDPE belt layer 3 and the PP single-wall corrugated pipe 4, and improve appearance quality of a product.

When the PP single-wall corrugated pipe 4 is produced in a coating mode, the PP single-wall corrugated pipe 4 penetrates through a through hole of the die 1 and moves from the rear end 13 of the die to the front end 12 of the die, meanwhile, an extruder supplies molten HDPE raw materials to an O-shaped flow groove formed between the die 1 and the pipe core 2 to form an O-shaped HDPE belt layer 3, the PP single-wall corrugated pipe 4 and the O-shaped HDPE belt layer 3 move in the same direction and at the same speed, and a coating layer is formed on the outer side of the PP single-wall corrugated pipe 4.

Example 1.

In this embodiment, the ratio of the straight segment length of the die front end 12 of the die 1 to the die inner diameter is 1: 7, increasing the length of the front end 12 of the mouth mold to improve the extrusion compactness of the material flow and also stabilize the material flow; and the ratio of the length of the transition section 15 to the die front end 12 is designed to be 1: 5, the transition section 15 makes the wall thickness of bush front end 12 be linear reduction, through reducing the wall thickness of bush front end 12, reduces the cladding clearance of PP single wall bellows 4 and "O" type HDPE belting layer 3, prevents that the too big phenomenon of curling inwards takes place in "O" type HDPE belting layer 3 that makes in clearance, improves the cladding surface smoothness.

Example 2.

In this embodiment, the ratio of the straight segment length of the die front end 12 of the die 1 to the die inner diameter is 1: 6, the extrusion compactness of the material flow is improved by expanding the length of the front end 12 of the mouth die, and the material flow can be stabilized; and the ratio of the length of the transition section 15 to the die front end 12 is designed to be 1: 6, the transition section 15 makes the wall thickness of bush front end 12 be linear reduction, through reducing the wall thickness of bush front end 12, reduces the cladding clearance of PP single wall bellows 4 and "O" type HDPE belting layer 3, prevents that the too big phenomenon of curling inwards takes place in "O" type HDPE belting layer 3 that makes in clearance, improves the cladding surface smoothness.

The above embodiments only describe the preferred embodiments of the present invention, and do not limit the concept and scope of the invention, and various modifications and improvements made to the technical solutions of the present invention without departing from the design concept of the present invention are within the protection scope of the present invention.

Claims

1. The combined cladding die for the Krah pipe is characterized by comprising a die 1 and a tube core 2, wherein the die 1 comprises a threaded joint 11, a die front end 12, a die rear end 13, a transition section 14 and a contraction section 15, the tube core 2 comprises a clamping module 21, a clamping groove 22 and a blocking block 23, the clamping groove 22 is located in the middle of the clamping module 21, the tube core 2 is in a hollow cylinder shape with a plurality of outer diameters and is sleeved at the die front end, an "O" -shaped HDPE belt layer 3 is formed and extruded through an "O" -shaped gap between the die 1 and the tube core 2, a PP single-wall corrugated pipe 4 penetrates from the inner side of the die rear end 13 to the inner side of the die front end 12, and the forming extrusion of the "O" -shaped HDPE belt layer 3 and the penetrating movement of the PP single-wall corrugated pipe 4 are simultaneously carried out.

2. The composite overmold for a Clar pipe as recited in claim 1, wherein one-half of the difference between the inside diameter of the core 2 and the outside diameter of the die tip 12 is equal to the thickness of the "O" HDPE tape layer 3.

3. The combination overmold of claim 1, wherein the detent groove 22 is in the form of a recessed ring for detent of the core in the outer body.

4. The composite cladding die for a clarinet according to claim 1, wherein the transition between the rear end 13 and the front end 12 is a cone, and the transition section 14 is a smooth curved surface with a circular arc shape.

5. The composite cladding die for a clarinet according to claim 1, wherein the die tip 12 has an elongated flat cylindrical shape, and the ratio of the length of the die tip 12 to the inner diameter of the die 1 is 1: (3-7).

6. The composite cladding die for a krah pipe as claimed in claim 1, wherein the die tip 12 is provided with a constriction 15 at the most forward edge, the outer diameter of the die tip 12 is reduced by the constriction 15, and the ratio of the length of the constriction 15 to the length of the die tip 12 is 1: (4-8).

7. The mold assembly of claim 1, wherein the right edge surface of the block 23 is substantially coplanar with the initially reduced circular profile of the transition section 15.