Wuhan Handern special-shaped production equipment
DATE：2020/12/10 9:36:20 / READ： / SOURCE：This station
Wuhan Handern special-shaped production equipment
Profile production equipment is the same as pipe and sheet extrusion molding, mainly including extruder, die, shaping device, cooling device, traction device, cutting device or coiling device, but the structure of the die shaping device is different. In addition, according to the special requirements of profiled materials, it is sometimes necessary to add some special devices, such as punching device, tailor welding device, insert conveying device, etc.
handern.com PE Breathable Film Machinery
1. Extruder and die
The profile extruder does not require a special structure, and general extruders suitable for various resins can be used. Although both single-screw or twin-screw extruders can be used, hard polyvinylidene, especially when powders are used to directly extrude large profiles, twin-screw extruders are recommended, and single-screw extruders are generally used for small profiles. . In order to strengthen the strength of profiled materials, many kinds of profiled materials are embedded with metal materials, so some extruders use hollow screws to facilitate the passage of metal inserts.
The plastic melt that enters the die from the extruder changes from a cylindrical shape to a cross section close to the shape of the product. This transformation must change the shape of the flow channel section. There are two basic methods:
(1) A streamlined die with good flow conditions. The cross section of the runner gradually changes from the figure to the product shape.
(2) "Plate die" with a sharp change in the cross section of the runner. The feature of the plate die is that as long as the die section is replaced, it can be adapted to products of different shapes, while the other parts are composed of standard components, so the die is adjusted , Installation is very easy. The relationship between the shape of the profile die and the shape of the product is shown in Figure -2. To obtain a square section product as shown in Figure 1, you must use a die as shown in Figure 9-29b. If you use a die as shown in Figure 9-29d, You will get a product as shown in Figure -29c. The molding surface of the die is the last part of the mold to adjust the flow of the molten material and give the product the required shape. The main parameters of the molding surface are the gap T of the die lip and the length L of the molding surface. They are determined by factors such as the type of resin and the control speed. It is expressed in the form of TS/T (TS is the wall thickness of the product) and L/T. handern.com PE Breathable Film Machinery
When extruding profiled materials with a large difference in thickness, generally the forming surface of the thick part should be as long as possible, and the thin part should be shorter, so that the extrusion pressure distribution is roughly uniform.
2. Auxiliary device
(1) The shaping device for profiled materials has the following 6 types
①Multi-plate type shaping: Arrange one or several shaping plates into the water, and shape it step by step.
②Sliding type setting The simple sliding type setting mold is a flat metal plate with the same shape as the product. In order to strengthen the contact, the metal mold should put a little pressure on the product.
③Pressure shaping is to make the outer wall of the pipe extruded from the die and the inner wall of the sizing sleeve next to the die to be melted and cooled, and the outer diameter is determined. This type of shaping method must pass compressed air into the pipe to apply pressure.
④Vacuum shaping This type of shaping die is mainly used for the extrusion molding of hollow profiles.
⑤Inner core shaping This shaping method is suitable for the extrusion of general tubular profiles.
⑥Roll shaping Roll shaping can be said to be a deformation of profile forming. The material is extruded from a special T-shaped die and then laminated by the roller method to produce plastic corrugated board, which is also a process for forming profiled materials. The length of the profiled mold should be determined according to the profile section size and production efficiency. handern.com PE Breathable Film Machinery
There are two main considerations in determining the size of the mold cavity: 1) the shrinkage change of the profile parison and 2) the draft change of the profile parison during the entire setting process in the mold. These two aspects will cause the profile ruler after shaping to be smaller than the cavity size of the setting mold.
For the shrinkage changes caused by the characteristics of the materials in the shaping process, as long as the shaping shrinkage rate of various materials in the production of extruded profiles can be controlled. Of course, the degree of complexity, geometric shape and wall thickness of the profile is different, and the shrinkage rate is also different.
Profile production equipment is the same as pipe and sheet extrusion molding, mainly including extruder, die, shaping device, cooling device, traction device, cutting device or coiling device, but the structure of the die shaping device is different. In addition, according to the special requirements of profiled materials, it is sometimes necessary to add some special devices, such as punching device, tailor welding device, insert conveying device, etc.
handern.com PE Breathable Film Machinery
1. Extruder and die
The profile extruder does not require a special structure, and general extruders suitable for various resins can be used. Although both single-screw or twin-screw extruders can be used, hard polyvinylidene, especially when powders are used to directly extrude large profiles, twin-screw extruders are recommended, and single-screw extruders are generally used for small profiles. . In order to strengthen the strength of profiled materials, many kinds of profiled materials are embedded with metal materials, so some extruders use hollow screws to facilitate the passage of metal inserts.
The plastic melt that enters the die from the extruder changes from a cylindrical shape to a cross section close to the shape of the product. This transformation must change the shape of the flow channel section. There are two basic methods:
(1) A streamlined die with good flow conditions. The cross section of the runner gradually changes from the figure to the product shape.
(2) "Plate die" with a sharp change in the cross section of the runner. The feature of the plate die is that as long as the die section is replaced, it can be adapted to products of different shapes, while the other parts are composed of standard components, so the die is adjusted , Installation is very easy. The relationship between the shape of the profile die and the shape of the product is shown in Figure -2. To obtain a square section product as shown in Figure 1, you must use a die as shown in Figure 9-29b. If you use a die as shown in Figure 9-29d, You will get a product as shown in Figure -29c. The molding surface of the die is the last part of the mold to adjust the flow of the molten material and give the product the required shape. The main parameters of the molding surface are the gap T of the die lip and the length L of the molding surface. They are determined by factors such as the type of resin and the control speed. It is expressed in the form of TS/T (TS is the wall thickness of the product) and L/T. handern.com PE Breathable Film Machinery
When extruding profiled materials with a large difference in thickness, generally the forming surface of the thick part should be as long as possible, and the thin part should be shorter, so that the extrusion pressure distribution is roughly uniform.
2. Auxiliary device
(1) The shaping device for profiled materials has the following 6 types
①Multi-plate type shaping: Arrange one or several shaping plates into the water, and shape it step by step.
②Sliding type setting The simple sliding type setting mold is a flat metal plate with the same shape as the product. In order to strengthen the contact, the metal mold should put a little pressure on the product.
③Pressure shaping is to make the outer wall of the pipe extruded from the die and the inner wall of the sizing sleeve next to the die to be melted and cooled, and the outer diameter is determined. This type of shaping method must pass compressed air into the pipe to apply pressure.
④Vacuum shaping This type of shaping die is mainly used for the extrusion molding of hollow profiles.
⑤Inner core shaping This shaping method is suitable for the extrusion of general tubular profiles.
⑥Roll shaping Roll shaping can be said to be a deformation of profile forming. The material is extruded from a special T-shaped die and then laminated by the roller method to produce plastic corrugated board, which is also a process for forming profiled materials. The length of the profiled mold should be determined according to the profile section size and production efficiency. handern.com PE Breathable Film Machinery
There are two main considerations in determining the size of the mold cavity: 1) the shrinkage change of the profile parison and 2) the draft change of the profile parison during the entire setting process in the mold. These two aspects will cause the profile ruler after shaping to be smaller than the cavity size of the setting mold.
For the shrinkage changes caused by the characteristics of the materials in the shaping process, as long as the shaping shrinkage rate of various materials in the production of extruded profiles can be controlled. Of course, the degree of complexity, geometric shape and wall thickness of the profile is different, and the shrinkage rate is also different.
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