Concentric sleeve type five-layer coextrusion film blower handpiece

Abstract

Disclosed is a concentrically telescopic, five-layered co-extrusion blow-moulding machine head, comprising five passage system sets, wherein each passage system set correspondingly guides the flow of one layer of molten material; each passage system set comprises one layer of helical passage located at the upper part of the machine head and a total feed inlet located at the lower part of the machine head; four layers of distribution plates are provided at the lower part of the machine head, including a bottom layer distributing plate, a second layer distributing plate, a third layer distributing plate and a fourth layer distributing plate; end points of all forty horizontally arranged branch passages of the five passage system sets are located on the same circle on a third interface, the eccentric distances of the end points of the forty horizontally arranged branch passages are all consistent and equal, and greater than the eccentric distance of a vertical branch passage of the first passage system set; and end points of the eight horizontally arranged branch passages of each passage system set are uniformly distributed in a circumferential direction, end points of two adjacent horizontally arranged branch passages of the same passage system set are staggered by a position angle of 45°. The blow-moulding machine can produce a very wide five-layered co-extruded plastic film and the machine head thereof is small in volume and easy to machine.

Description

technical field [0001] The invention belongs to the technical field of plastic film blowing equipment, in particular to a concentric sleeve type five-layer co-extrusion film blowing head for producing five-layer co-extrusion plastic films. Background technique [0002] There are two main types of multi-layer co-extrusion blown film heads for producing plastic films. The first type is superimposed multi-layer co-extrusion blown film heads, and the second type is concentric sleeve multi-layer co-extrusion blown film heads. The structures of these two types of dies are very different, and the flow modes of molten materials are also very different during operation. [0003] The diameters of the ring-shaped die openings of each layer of materials in the superimposed multi-layer co-extrusion blown film head are the same, and the arrangement is in the form of superimposing up and down, and they are all located next to a ring-shaped vertical flow channel. When extruding, each layer...

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Problems solved by technology

[0009] 1. The machine head is very bulky and consumes a lot of alloy steel, which will undoubtedly increase the production cost (the production of film blowing machine heads requires special alloy steel, which is very expensive);

[0010] 2. The large size and heavy weight of the machine head make processing very difficult, and even make ordinary processing machine tools difficult to perform processing tasks;

[0011] 3. Loading, unloading, and transportation are troublesome, and ordinary cranes are incapable of lifting tasks;

[0012] 4. The size of the machine head is large, resulting in a long preheating time for the production of plastic film, and a large energy consumption in the production process;

[0013] 5. The large volume of the machine head means that the sealing interface area is large and the sealing is more difficult;

[0014] 6. The cross-section of the radial flow channel is small and the length of their continuous extension is large (the length of each radial flow channel exceeds 3 meters), and the flow channel with a small cross-section has a large pressure loss on the molten material, so it is necessary for the production of the machine head High extrusion pressure will aggravate the degree of sealing difficulty, and the precision requirements for the sealing interface are quite high;

[0015] 7. The central part of the machine head is occupied by the material flow channel 5 of each set of flow channel systems, so the air intake channel 10 passing through the lower part of the machine head can only be arranged in the eccentric part, and is sandwiched by two radial flow channels 44 In the fan-shaped area between, such as Figure 5 shown; and the large-diameter bubble must require the diameter of the inlet channel to be large enough, so the eccentric distance of the inlet channel is required to be large enough (if the eccentric distance is too small, the width of the fan-shaped area between the two radial flow channels cannot Accommodate the air intake channel), which in turn determines that the diameter of the lower part of the nose is difficult to reduce

[0016] Due to the above reasons, in the prior art, there is no concentric sleeve-type five-layer co-extrusion blown film equipment with an extrusion die diameter exceeding 3 meters. Extrusion equipment for production, generally only single-layer extrusion equipment can be used for production

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