JP2889958B2 - Method for forming embossed pattern on film-coated foamed resin pipe surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an embossed pattern on a surface of a film-coated foamed resin pipe which forms an embossed pattern on an outer peripheral surface of the film-coated foamed resin pipe used as a heat insulating material or the like.

[0002]

2. Description of the Related Art A foamed resin pipe made of cross-linked polyethylene or the like is widely used as a heat insulating material for covering a refrigerant pipe connected between an outdoor unit and an indoor unit of an air conditioner such as a cooling unit. The outer peripheral surface of this type of foamed resin pipe is usually coated with a resin film to prevent damage.
It is widely practiced to form embossments on the outer peripheral surface instead of simply keeping the flat outer peripheral surface. By forming this embossment, the film is hardly torn during the construction and handling of the foamed resin pipe, and the effect of enhancing the protection function is also obtained, which also prevents trauma, and furthermore, buckling is less likely to occur when bent. The effect of improving the flexibility is obtained, and furthermore, the design is excellent and the aesthetic appearance is favorable. FIG. 9 shows the embossed film-coated foamed resin pipe 1. Reference numeral 2 denotes a foamed resin pipe, and reference numeral 3 denotes a film. The embossment 4 on the outer peripheral surface is, for example, a large number of rectangular portions surrounded by lattice-shaped grooves 4a as shown in the figure.
It is an uneven pattern that becomes

[0003] A conventional typical method for manufacturing the above-mentioned embossed film-coated foamed resin pipe 1 is extrusion molding, as shown in FIG.
And a step of passing the resin sheet 6 through a heating furnace to cause foaming and crosslinking at the same time to form a crosslinked foamed resin sheet 7 as shown in FIG. A first line having a step of winding into a coil and a film 8 are attached to the foamed resin sheet 7 by heating and pressing with a roll, and at the same time, an emboss is formed on the surface and an emboss is formed as shown in FIG. A laminating / embossing step for obtaining a film-coated foamed resin sheet 9;
A slitting step of slitting the embossed film-coated foamed resin sheet 9 to a predetermined width dimension corresponding to a pipe diameter,
(FIG. 10 (d)) The second line having the step of winding up and the slit-coated embossed film-coated foamed resin sheet 9 ′ are attached to a vertical attachment ring arranged in tandem while closing in a circular cross section. And a third line having a former step of heat-sealing the closed end faces by heating the soldering iron to form a pipe as shown in FIG. Was something.

As shown in FIG. 11, the step of forming an emboss on the surface of the film-covered foamed resin sheet is performed by preheating the film 8 and blowing hot air from a blower 10 to heat the film 8 while a pair of upper and lower cylindrical rolls are formed. The foamed resin sheet 7 and the film 8 are fed between the rolls 11 and 12 so that the foamed resin sheet 7 and the film 8 are separated from each other by the upper embossed roll 11 and the lower roll having a simple cylindrical surface. At the same time, the emboss is formed on the surface while being adhered to each other by pressurization with the substrate 12. By the way, as described above, instead of forming a pipe section directly, an embossed film-coated foamed resin sheet is embossed and then closed in a circular shape to form an embossed film-coated foamed resin pipe. This is because it is difficult to form an emboss on the outer peripheral surface. That is, in the case of a film-coated foamed resin sheet, the upper and lower rolls 11,
12 can apply a sufficiently large pressing force, so that embossing can be formed even if the pressing time is instantaneous. However, in the case of a film-coated foamed resin pipe, it is necessary to obtain a sufficiently large pressing force with the upper and lower rolls. Is difficult, and the pressurizing time is also instantaneous, and a sufficient cooling holding time required for forming the emboss cannot be obtained, so that the emboss cannot be formed on the outer peripheral surface.

[0005]

In the above conventional method,
Since the number of processes is large and three lines are required, productivity is low, a device for taking up and sending out a foamed sheet is required for each process, and equipment costs increase. Further, since the left and right edges of the wide foamed resin sheet are thinner than a specified thickness, it is necessary to cut off the edges, and the edges (ears) become scraps, which lowers the yield. Furthermore, since there are seams, the strength of the pipe naturally decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and can simplify the manufacturing process of a film-coated foamed resin pipe to improve the productivity, improve the yield, and improve the seam. It is an object of the present invention to provide a method for forming an embossed pattern on the surface of a film-coated foamed resin pipe capable of obtaining an embossed film-coated foamed resin pipe without any strength.

[0007]

SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems is a method for forming an embossed pattern on the surface of a film-coated foamed resin pipe by forming an embossed pattern on the outer peripheral surface of the film-coated foamed resin pipe. Around the outer periphery of the film-coated foamed resin pipe sent endlessly at the same speed along the film-coated foamed resin pipe, and from a flat shape to a cylinder within a certain distance along the film-coated foamed resin pipe. Wrapped in the cylindrical portion of the mesh formed into a flat shape and returned to the flat shape again, and heating the outer peripheral surface of the cylindrical portion of the mesh while increasing the internal pressure of the film-coated foamed resin pipe to an atmospheric pressure or higher. And

According to a second aspect of the present invention, compressed air is supplied to the inside of the film-coated foamed resin pipe from a distal end opening on the downstream side in the feeding direction, and the film-coated foamed resin pipe pushes an upstream position from a portion along the net. It is characterized by being crushed and closed.

A third aspect of the present invention is characterized in that, in the first or second aspect, a perforated sheet having a large number of holes corresponding to the embossed pattern is used in place of the mesh.

[0010]

In the above construction, the film-coated foamed resin pipe is fed over a fixed distance range while being wrapped by the cylindrical portion of the net or the perforated sheet that goes around endlessly. During this time, the internal pressure of the film-coated foamed resin pipe is maintained at or above the atmospheric pressure, and the outer peripheral surface is heated, so that the film-coated foamed resin pipe expands at the portion of the mesh or the perforated sheet located at the hole. Then, an embossed pattern corresponding to the shape of the mesh or the hole is formed on the outer peripheral surface.

In this case, since the contact time between the outer peripheral surface of the film-coated foamed resin pipe and the net or the perforated sheet is sufficiently long, the embossed pattern can be formed without particularly increasing the internal pressure of the film-coated foamed resin pipe. Is possible. In addition, since a certain cooling period can be secured while being wrapped with the mesh or the perforated sheet, the emboss does not return to the original state and becomes flat.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method of the present invention will be described below with reference to FIGS. FIG. 1 is a side view showing the vicinity of an embossed pattern forming step in an apparatus for manufacturing an embossed film-coated foamed resin pipe, and reference numeral 21 denotes a foamed resin pipe.
The foamed resin pipe 21 is formed into an unfoamed resin pipe by an extruder (not shown), and then passes through a foaming device (not shown) to form a foamed resin pipe 21. The foamed resin pipe 21 is continuous from the left side of FIG. Will be sent. On the outer periphery of the foamed resin pipe 21, a film 23
Is coated. That is, the film 23 coated with the hot-melt adhesive is continuously unwound from the film roll 23 'and, for example, four tape longitudinally attached guide rings 24a, 24b, which alternately come into contact with the inside and outside of the film 23.
Guided by a tape covering 25 having a conical inner surface made of 24c, 24d and a Teflon sheet, the tape is gradually formed into a cylindrical shape, covered on the outer peripheral surface of the foamed resin pipe 21, and heated by a heating head 26 having a heater 26a.
It is bonded to the outer peripheral surface of the foamed resin pipe 21. When the foamed resin pipe 21 passes through the heating head 26, it becomes a film-coated foamed resin pipe 27. As shown in FIG. 3, the film-coated foamed resin pipe 27 without emboss is fed and driven by a feed roll 28 using a flat tire while being crushed so as to close the internal space as shown in FIG. The non-embossed film-coated foamed resin pipe 27 passes through the embossed pattern forming device 30 and becomes an embossed film-coated foamed resin pipe 27A having an embossed pattern formed on the outer peripheral surface. The feed roll 29 feeds and drives the film-coated foamed resin pipe 27A.

FIG. 2 shows the details of the embossed pattern forming device 30. In FIG. 2, reference numeral 31 denotes a net-like body such as an endless wire net having a width substantially equal to the circumference of the film-coated foamed resin pipe 27, and a plurality of pulleys 3 including a driving pulley.
2 and driven endlessly along the film-coated foamed resin pipe 27 at the same speed as the feed speed. Then, two round pipes 34 and 35 made of metal are arranged in tandem at positions where the film-coated foamed resin pipe 27 passes, and a net-like body 31 forming a substantially inverted trapezoidal loop is formed.
4 and 5, along with the film-coated foamed resin pipe 27, into the round tubes 34 and 35.
As shown in FIG. 7, the net-like body 31 is guided and regulated by the round tube 34 to be changed from a flat shape to a cylindrical shape, wraps the film-coated foamed resin pipe 27, and after leaving the round tube 35, the regulation is released to a flat shape. I'm going back. In addition, the round tubes 34 and 35
As shown in FIG. 6 and FIG.
It has an inner diameter substantially equal to the outer diameter of the cylindrical net-like body 31 surrounding the outer peripheral surface of the film-coated foamed resin pipe 27.

A heater 36 is provided on the outer periphery of the upstream round tube 34 for heating the round tube 34 to heat the outer periphery of the film-coated foamed resin pipe 27 therein.
Further, an annular cooling water spray device 37 having a nozzle for spraying cooling water is provided between the two round tubes 34 and 35.

Although not shown, compressed air is supplied from the opening at the downstream end in the feed direction of the film-coated foamed resin pipe 27A as indicated by an arrow, and the film is coated by the feed roller 28 as described above. By crushing and closing the foamed resin pipe 27, the internal pressure of the film-coated foamed resin pipe 27 at the position of the round pipe 34 is maintained at or above the atmospheric pressure. Film-coated foam resin pipe 2
As means for supplying the compressed air into the tube 7, for example, when the film-coated foamed resin pipe 27A is wound around a drum, the tip end opening of the film-coated foamed resin pipe 27A is connected to a rotary coupling attached to the drum. Compressed air may be sent from the rotary coupling. Further, the position of the tip of the film-coated foamed resin pipe 27A sent out from the feed roll 29 is fixed, the intermediate portion is accumulated without restraint in the container, and compressed air is supplied from the coupling connected to the opening at the tip. It can also be sent. In addition, any means for increasing the internal pressure of the film-coated foamed resin pipe 27 to the atmospheric pressure or more is optional.

In the above-described apparatus, a foamed resin pipe 21 formed into a resin pipe by an extruder (not shown) and then foamed through a foaming device (not shown) is covered with a film 23 by a film coating device 22. The film-coated foamed resin pipe 27 is obtained. When the film-coated foamed resin pipe 27 passes through the embossed pattern forming device 30, an embossed pattern is formed on the outer peripheral surface thereof. That is, the mesh body 31 is driven and guided by the pulley 32 to orbit in an inverted trapezoidal loop, and the upper side moves parallel to the film-coated foamed resin pipe 27 at the same speed. At the upper side portion, the net-like body 31 becomes cylindrical as shown in FIG. 6 through a state in which the left and right portions in FIG. 5 are slightly bent from the flat state in FIG.
The film-coated foamed resin pipe 27 is wrapped in tight contact with the entire outer periphery thereof. On the other hand, a film-coated foamed resin pipe 2
7 is, for example, 130
While being heated to about 140 ° to soften, and the internal pressure is increased to about 0.1 to 0.3 kg / cm by compressed air, for example, the portion of the mesh body 31 located at the mesh expands, An embossed pattern is formed such that a portion pressed against the net-like body 31 becomes a groove. In this case, since the contact time between the outer peripheral surface of the film-coated foamed resin pipe 27 and the mesh body 31 is sufficiently long, the emboss can be formed without a large pressing force. After passing through the round pipe 34, it is cooled by the cooling water sprayed from the cooling water spraying device 37, and a certain cooling period is secured in the subsequent round pipe 35 while being wrapped by the mesh 31, so that the round The emboss formed in the tube 34 solidifies and does not return to its original flat surface.

The net-like body 31 is made of a wire made of various metallic materials such as iron, stainless steel, brass, copper, aluminum or the like, or a non-metallic material such as Teflon, glass, etc., in a plain weave or twill weave. It can be used, and the shape of the mesh is not particularly limited and is arbitrary. Further, it is preferable that the mesh body 31 has an appropriate flexibility. Therefore, the material, hardness, softness, wire diameter, woven pitch and the like are appropriately selected. Further, in the embodiment, the round tube 34 is heated by the heater 36 as the heating means. However, other methods such as a method of providing a blower at the position of the cooling water spraying device 37 and blowing hot air with the blower may be adopted. it can. In addition, cooling means
It is conceivable to use air cooling instead of water cooling, and various methods can be adopted.

In the above-described embodiment, the mesh 31 is used to form the embossed pattern. However, instead of the mesh 31, a hole having a large number of holes corresponding to the embossed pattern is provided. Sheets can also be used. In this case, the shape of the hole is not particularly limited, as in the mesh of the mesh body 31, and is arbitrary. As a material for the sheet, a metal such as stainless steel, copper, or aluminum is suitable, but a nonmetallic sheet that is resistant to tension and bending can also be used.

The means for obtaining the film-coated foamed resin pipe is not particularly limited. That is, the foaming means for obtaining the foamed resin pipe may be a foaming agent decomposition method or a liquid or gas mixing method. The foamed resin pipe may or may not be cross-linked, and the method of cross-linking is optional. In addition, the film-coated foamed resin pipe to which the present invention is applied is mainly used as a heat insulating material, but can be applied not only to a refrigerant pipe of an air conditioner but also to various pipes such as a hot water supply pipe and an LPG pipe. It may be other than the use as a material.

[0020]

According to the method of the present invention, an embossed pattern can be directly formed on the surface of a film-coated foamed resin pipe, and the process is significantly simplified. In other words, the process from resin extrusion to the final step of obtaining an embossed film-coated foamed resin pipe can be completed on a single line, significantly improving productivity, lowering equipment costs, and significantly reducing manufacturing costs. I do. Also, there is no need to cut off the edges of the wide film-coated foam resin sheet as in the past, so no scrap is generated.
The yield is improved. Furthermore, since there is no seam, the strength as a film-coated foamed resin pipe is greatly improved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the method of the present invention, and is a side view in the vicinity of a step of forming an embossed pattern in an apparatus for producing an embossed film-coated foamed resin pipe.

FIG. 2 is an enlarged side view of an embossed pattern forming step in FIG. 1;

FIG. 3 is an enlarged sectional view taken along the line AA in FIG. 2;

FIG. 4 is an enlarged sectional view taken along line BB in FIG. 2;

FIG. 5 is an enlarged sectional view taken along the line CC in FIG. 2;

FIG. 6 is an enlarged sectional view taken along the line DD in FIG. 2;

FIG. 7 is a sectional view taken along line EE in FIG. 2;

FIG. 8 is a partially enlarged sectional view of FIG. 6;

FIG. 9A is a side view for explaining a general structure of an embossed film-coated foamed resin pipe, and FIG. 9B is a sectional view of the same.

FIG. 10 is an explanatory view showing a manufacturing process of a conventional embossed film-coated foamed resin pipe.

FIG. 11 is an explanatory view of a conventional embossing method.

[Explanation of symbols]

1, 27A Embossed film-coated foamed resin pipe 2, 21 Foamed resin pipe 3, 23 Film 4 Embossed 27 Film-coated foamed resin pipe 28 Feed roll for closing pipe 30 Embossed pattern forming device 31 Reticulated body 34 Round pipe 35 Round pipe 36 heater 37 cooling water sprayer

Claims (3)

(57) [Claims] 1. A method of forming an embossed pattern on the surface of a film-coated foamed resin pipe, which forms an embossed pattern on the outer peripheral surface of the film-coated foamed resin pipe, comprising the steps of: The net-shaped cylinder of the net-like body that goes around the film-coated foamed resin pipe endlessly at the same speed as this one, and changes from a flat shape to a cylinder within a certain distance along the film-coated foamed resin pipe and returns to the flat shape again. Wrapped in a shape
A method of forming an embossed pattern on a surface of a film-coated foamed resin pipe, wherein an outer peripheral surface is heated while an internal pressure of the film-coated foamed resin pipe is increased to an atmospheric pressure or higher in a cylindrical portion of the mesh body. 2. A compressed air is supplied to the inside of the film-coated foamed resin pipe from a downstream end opening in a feed direction, and a position upstream of a portion of the film-coated foamed resin pipe along the net is crushed and closed. 2. The method for forming an embossed pattern on the surface of a film-coated foamed resin pipe according to claim 1, wherein 3. The film-coated foamed resin pipe surface according to claim 1, wherein a perforated sheet provided with a large number of holes corresponding to an embossed pattern is used in place of the mesh. Emboss pattern forming method.