CN118124115A - Method for manufacturing aluminum plastic pipe composite - Google Patents

Abstract

The invention discloses a manufacturing method of an aluminum-plastic composite pipe, which comprises the following steps: extruding to form an inner tube, and coating hot melt adhesive on the outer surface of the inner tube; the inner tube and the aluminum belt synchronously advance, and the aluminum belt is coiled into an aluminum pipe by the rolling wheel group to wrap the aluminum pipe outside the inner tube; and coating hot melt adhesive outside the aluminum pipe, extruding again to form an outer pipe, and wrapping the outer pipe. According to the invention, one surface of the aluminum strip is polished to be rough by polishing the aluminum strip, and the surface is the inner surface of the aluminum pipe after the aluminum strip is subsequently formed, so that the aluminum strip has better bonding firmness with hot melt adhesive; under the condition of polishing the two sides, the two sides of the aluminum belt are roughened surfaces, so that the outer surface of the aluminum pipe is roughened, and the aluminum pipe, the inner pipe and the outer pipe can be welded better and more firmly.

Description

Method for manufacturing aluminum plastic pipe composite

Technical Field

The invention belongs to the technical field of pipe manufacturing, and particularly relates to a manufacturing method of aluminum-plastic pipe compounding.

Background

The aluminum-plastic composite pipe is a common water heating pipe, and the basic structure of the aluminum-plastic composite pipe is five layers, namely, plastic, hot melt adhesive, aluminum alloy, hot melt adhesive and plastic are sequentially arranged from inside to outside, wherein the plastic layer can be Polyethylene (PE) or crosslinked Polyethylene (PEX) and the like. In order to produce the aluminum-plastic composite pipe, the common process comprises the main steps of inner pipe extrusion, inner glue extrusion, aluminum strip unreeling, aluminum pipe shaping, heating, outer glue extrusion, outer pipe extrusion and the like as disclosed in China patent 201410182831.5. Specifically, firstly, producing a plastic pipe of an inner layer, then coating hot melt adhesive on the outer wall of the inner pipe, simultaneously preparing a proper aluminum strip coil and extruding the inner pipe to move in the same direction, enabling the width of the aluminum strip to be equal to the circumference of the aluminum pipe in design, enabling the aluminum strip to be attached to the inner pipe, bending the planar aluminum strip into a pipe shape through a series of rolling wheels to cover the inner pipe, and simultaneously heating to enable the hot melt adhesive to tightly bond the inner pipe and the aluminum pipe into a whole; and then coating a second layer of hot melt adhesive outside the aluminum pipe, and then passing the aluminum pipe through a second extrusion device to form an outer pipe, thereby manufacturing the complete aluminum-plastic composite pipe with a five-layer structure.

The production equipment of the aluminum-plastic composite pipe is a production line and sequentially comprises a first extrusion device, an inner glue coating device, an aluminum belt conveying device, a roller set, an outer glue coating device and a second extrusion device, wherein the devices are not necessarily physically connected, and the production of the aluminum-plastic composite pipe is completed through the arrangement sequence of space.

In the prior art, the aluminum pipe is formed by bending a plane sheet shape in a mechanical way, and the aluminum pipe cannot be perfectly round mathematically, and the hot melt adhesive is required to fill the gap between the aluminum pipe and the plastic pipe, particularly the gap between the aluminum pipe and the inner pipe, which is more remarkable. Under the condition that the hot melt adhesive is not distributed in place, insufficient adhesion force can be caused, so that the phenomenon of slipping between the aluminum pipe layer and the inner pipe layer can be caused.

Disclosure of Invention

The invention aims to provide a manufacturing method of an aluminum-plastic composite pipe, which can improve the welding effect between an aluminum pipe and a plastic pipe.

For this purpose, the invention adopts the following technical scheme: the manufacturing method of the aluminum-plastic composite pipe comprises the following steps:

1) Extruding to form an inner tube, and coating hot melt adhesive on the outer surface of the inner tube;

2) The inner tube and the aluminum belt synchronously advance, and the aluminum belt is coiled into an aluminum pipe by the rolling wheel group to wrap the aluminum pipe outside the inner tube;

3) Coating hot melt adhesive on the outer side of the aluminum pipe, extruding again to form an outer pipe, and wrapping the outer pipe;

The method is characterized in that:

Between the step 1) and the step 2), the surface of the aluminum strip, which is close to the inner tube, is polished to be a rough surface.

Further, between step 1) and step 2), both surfaces of the aluminum tape are polished to be rough surfaces.

According to the invention, one surface of the aluminum strip is polished to be rough by polishing the aluminum strip, and the surface is the inner surface of the aluminum pipe after the aluminum strip is subsequently formed, so that the aluminum strip has better bonding firmness with hot melt adhesive; under the condition of polishing the two sides, the two sides of the aluminum belt are roughened surfaces, so that the outer surface of the aluminum pipe is roughened, and the aluminum pipe, the inner pipe and the outer pipe can be welded better and more firmly.

Drawings

FIG. 1 is a schematic diagram of an apparatus used in the present invention.

Fig. 2 is A-A view of fig. 1.

Fig. 3 is an enlarged view at B in fig. 1.

Detailed Description

See the drawings. The figure shows the core part of the aluminum plastic composite pipe production equipment, a first extrusion device (not shown) is produced according to the prior art to form an inner pipe 1, an aluminum belt conveying device (not shown) is used for conveying an aluminum belt 2 according to the prior art, the inner pipe 1 and the aluminum belt 2 move forwards at the same time, namely move from right to left in the figure 1 and respectively pass through an inner glue coating device 3 and a sand wheel set 5; it should be noted that the inner glue application device 3 and the grinding wheel set 5 should be located in different parts of the direction of movement from the point of view of space rationality of the production line, which are arranged one above the other for the sake of simplicity of illustration in the drawing, so that it is clear that they can be represented in one view.

The inner glue coating device 3 is annular in main body, the rubber tube 31 is connected to the outer side of the main body, the inner tube 1 passes through the annular main body, and the hot melt glue enters the annular main body from the rubber tube 31 and is coated on the surface of the inner tube.

The grinding wheel set 5 comprises an upper grinding wheel 51 and a lower grinding wheel 52, and the aluminum strip 2 passes through the upper grinding wheel and the lower grinding wheel to form close contact. The widths of the upper grinding wheel and the lower grinding wheel are not smaller than the width of the aluminum belt, and the upper grinding wheel and the lower grinding wheel move relatively; the upper grinding wheel and the lower grinding wheel are provided with rough surfaces, so that the grinding wheels polish the surfaces of the aluminum strips in the moving process of the aluminum strips. After passing through the grinding wheel set 5, the aluminum belt 2 has rough surfaces on the upper and lower surfaces.

After the inner tube and the aluminum belt respectively pass through the coating device 3 and the grinding wheel set 5, the surface of the inner tube is provided with hot melt adhesive, the surface of the aluminum belt is roughened, and the inner tube and the aluminum belt enter the grinding wheel set simultaneously. The rolling wheel group comprises a plurality of circumferential rolling wheels 41, the rotation direction of the rolling wheels 41 is parallel to the movement direction of the aluminum strip and the inner tube, and the aluminum strip 2 is curled upwards by the rim shape of the rolling wheels; the rear part of the circumferential rolling wheel also comprises radial rolling wheels 42 and 43, the radial rolling wheels are fixed and are perpendicular to the moving direction of the aluminum strip and the inner tube, taking the rolling wheel 42 as an example, the inner surface 421 of the rolling wheel is in a round table shape, the aluminum strip and the inner tube firstly pass through the larger bottom surface of the round table and then come out from the smaller top surface of the round table when moving, the aluminum strip 2 becomes an aluminum tube and is wrapped outside the inner tube 1, and in the process, hot melt adhesive is filled between the inner tube and the aluminum strip to become an independent inner adhesive layer, so that the inner tube and the aluminum strip are firmly bonded.

After the aluminum pipe and the inner pipe leave the roller group, the outer glue is coated once, and the outer pipe is extruded and formed through a second extrusion device, so that the complete aluminum-plastic composite pipe is formed. The subsequent steps are all prior art and are not shown in the figure.

Claims (2)

1. The manufacturing method of the aluminum-plastic composite pipe comprises the following steps:

1) Extruding to form an inner tube, and coating hot melt adhesive on the outer surface of the inner tube;

2) The inner tube and the aluminum belt synchronously advance, and the aluminum belt is coiled into an aluminum pipe by the rolling wheel group to wrap the aluminum pipe outside the inner tube;

3) Coating hot melt adhesive on the outer side of the aluminum pipe, extruding again to form an outer pipe, and wrapping the outer pipe;

The method is characterized in that:

Between the step 1) and the step 2), the surface of the aluminum strip, which is close to the inner tube, is polished to be a rough surface.

2. The method for manufacturing the aluminum-plastic composite pipe according to claim 1, wherein: between step 1) and step 2), both surfaces of the aluminum strip are polished to be rough surfaces.