JPH0890651A - Method of embossing coated foamed resin tube and heat insulation tube - Google Patents

Abstract

(57) [Abstract] [Purpose] A coated foamed resin tube having a resin coating layer is continuously textured, and no fins are generated due to the resin coating layer protruding on the surface thereof. (EN) A method and a heat-retaining cylinder that does not rupture when inserting a tube to be coated and does not corrode a copper tube even when used for heat-retaining a copper tube. [Structure] Covered foamed resin tube 4 conveyed downward
Has a cross-sectional shape obtained by dividing a circle having a diameter slightly smaller than the outer diameter of the resin coating layer into four arc shapes, and the embossed surface 6, 6, ... Is formed on the outer peripheral surface thereof. The surface of the coated foamed resin tube 4 immediately before passing through the seam 7 is surrounded by the press rolls 2, 2, 2 which are surrounded by the embossing rolls 1, 1, 1, 1 and arranged immediately before the seam 7 between the adjacent rolls. Press inward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for embossing a surface of a coated foamed resin tube, and a heat insulating tube obtained by the method.

[0002]

2. Description of the Related Art Tube molded articles made of foamed resin such as polyethylene are used for heat insulation and protection of water supply and drainage pipes and piping of air conditioners. In order to manufacture such a tube molded product, the side edges of the polyolefin resin foam sheet foamed by using the pyrolytic foaming agent are joined in a tubular shape by heat fusion or the like. Furthermore, when the foam is applied, wrinkles or scratches are not noticeable, and the surface is textured so as to obtain a high-quality appearance.
To make a tube molded product whose surface is embossed,
The side edges of the embossed foam sheet were joined together by heat fusion.

Japanese Unexamined Patent Publication (Kokai) No. 3-207639 discloses a method for texturing a tubular foam tube. A circle having a diameter slightly smaller than the outer diameter of a coated foam resin tube foamed after extrusion is formed into two or more arcs. There is disclosed a patterning processing method in which extrusion is performed by two or more rolls each having a textured pattern formed on a roll surface having a divided sectional shape.

[0004]

As in the conventional case, the embossed foamed sheet is processed into a tubular shape. When air is pressed into the tube so that the tubular body can be easily inserted therein, , The seams of the heat-sealed foam sheet may burst. Further, when the embossing process is performed by the method described in the above publication, the resin coating layer protrudes into a portion of a slight gap generated between the adjacent rolls, and a foamed resin like the coated foamed resin tube 4 shown in FIG. A tape-like fin 43 on the surface-textured coating layer 41 of the tube 40,
43, ... are formed. Therefore, there is a problem that the commercial value is reduced.

Further, when a foamed tube produced by using a pyrolytic foaming agent is used for keeping the temperature of a copper tube, ammonia or organic acid, etc., which is generated by the decomposition of the foaming agent and remains in the foamed body is gradually increased. There is a problem of invading.

The present invention solves the above-mentioned problems of the prior art, in which a coated foamed resin tube having a resin coating layer is continuously embossed, and the surface of the resin coating layer does not cause fins due to protrusion of the resin coating layer or the like. It is an object of the present invention to provide a method for providing a foamed resin tube with a grain and a heat-retaining cylinder that does not rupture when a tube to be covered is inserted and that does not corrode the copper tube even when used for heat-retaining the copper tube.

[0007]

According to a first aspect of the present invention, there is provided a method for embossing a coated foamed resin tube, wherein the coated foamed resin tube having a resin coating layer on its surface is slightly smaller than the outer diameter of the resin coating layer. A method for embossing a covered foamed resin tube, which has a cross-sectional shape obtained by dividing a circle of diameter into two or more arcs, and which is pressed by two or more pressing members having a textured pattern on the surface, wherein It is characterized in that the pressing roll arranged immediately before the seam of the pressing member presses at least one surface of the coated foamed resin tube immediately before or after passing through the seam.

According to a second aspect of the present invention, the endless belt is used as the pressing member.

According to a third aspect of the present invention, there is provided a method for embossing a coated foamed resin tube, wherein the coated foamed resin tube having a resin coating layer on its surface is formed into a circle having a diameter slightly smaller than the outer diameter of the resin coating layer. A method for embossing a coated foamed resin tube, which has a cross-sectional shape divided into two parts, and which is pressed by two or more pressing members having a texture pattern formed on the surface thereof, which is immediately after the seam of the adjoining pressing members. By the arranged heating tool, the coated foamed resin tube surface immediately after passing through the joint is melted, and the softened or melted portion is pressed by a pressing roll arranged subsequent to the heating tool. Is.

Further, the heat insulating cylinder according to claim 4 is formed by laminating a polyolefin resin by melt extrusion on an outer peripheral surface of a crosslinked polyolefin resin foam extruded and molded into a cylindrical shape by using a volatile foaming agent. A coating layer is provided, the surface of the coating layer is textured, and the texture is performed by the graining method according to any one of claims 1 to 3. To do.

The resin used in the foamed resin tube of the present invention is a polyolefin resin such as ethylene homopolymer, ethylene-α-olefin copolymer containing ethylene as a main component, propylene homopolymer and propylene as a main component. And copolymers thereof and the like. Examples of the α-olefin include 1-hexene, 4-methyl-1-pentene, 1-octene, 1-butene, 1-pentene and the like. Examples of the propylene copolymer include a block copolymer with ethylene or the like, a random copolymer, a terpolymer with ethylene, butene, or the like.

The coated foamed resin tube used in the present invention is obtained by continuously extruding a coating resin onto the surface of an extruded foamed tube. The above-mentioned coating resin is the same polyolefin resin as described above, and one having the same quality as the foamed resin tube is particularly preferable because it has excellent adhesiveness to the foamed resin tube. This coating resin is used as a non-foamed resin or a low-foamed resin foamed three times or less.

The pressing member used in the invention of claim 1 is the same as that described in the above-mentioned Japanese Patent Laid-Open No. 3-207639, and has a circumference slightly smaller than the outer diameter of the resin coating layer. It is a roll having a cross-sectional shape divided into two or more arcs and having an embossed pattern on its inner surface. The resin coated by extrusion is passed through the pressing member until it is in a molten state for graining, or when the resin is cooled and solidified, the coated resin layer is heated to a temperature above its melting temperature and pressed. When the member is passed, it is embossed.

In the method according to the first aspect, immediately before or after the coated foamed resin tube passes through the pressing member, the surface of the coated foamed resin tube corresponding to the joint of the adjacent pressing members is fixed to the outer peripheral surface of the pressing roll. Press.
The pressing roll may be provided both immediately before and after the pressing member. This prevents the resin that is the coating layer from squeezing out from the gap between the joints of the pressing members. If the pressing roll is provided both immediately before and after the pressing member, the occurrence of fins can be prevented more reliably. As the pressing roll, for example, one in which a disc having a cross-section of which the outer periphery is convexly bulged is rotatably supported by a bearing is preferably used.

When the pressing roll is arranged so as to push the resin coating layer to a portion slightly deeper than the seam of the pressing member, the pressing roll is rotated by the passage of the coated foamed resin tube and tends to rise, or the resin coating raised. Since the layers are pushed inward, no fins occur. Although the resin coating layer that has been pressed and recessed after passing through the pressing roll is slightly restored, no fin of the resin coating layer is formed on the surface of the coated foamed resin tube.

The invention according to claim 2 uses an endless belt as the pressing roll used in the method according to claim 1. The endless belt is, for example, as shown in FIG.
As shown in FIG. 2, a belt 27 having a grain pattern is suspended between two hourglass-shaped pulleys 25, 25. If such a belt is used, the time for pressing the surface of the coated foamed resin tube becomes long. , The graining effect becomes larger. Two
Reference numeral 6 is a shaft hole for inserting the rotary shaft.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the portion of the coating resin tube coming out from the joint of the pressing member is melted by a heating tool arranged therein. The fins of the formed resin coating layer are eliminated by heating above the temperature and pressing the coating resin in a molten state by a pressing roll arranged subsequent to the heating tool. Therefore, the pressing roll is provided only immediately after the pressing member. The pressing member may be an endless belt as described in claim 2.

The above-mentioned heating tool is not particularly limited as long as it can heat only the portion coming out of the joint of the pressing member, and it can blow hot air from a thin tube or radiant heat of a small heating heater. You may heat. The heating temperature is adjusted by the moving speed of the coated foamed resin tube.

Next, the foam used as the heat insulating cylinder according to claim 4 is one in which a crosslinkable polyolefin resin containing a chemical crosslinking agent is extruded into a tubular shape and simultaneously foamed with a volatile foaming agent. is there. This polyolefin resin is the same as that used in claim 1, but the crosslinking method by irradiation is not suitable because it is extruded into a tubular shape and foamed, and at the same time, the crosslinking proceeds, and it is crosslinked by a chemical crosslinking agent.

Examples of the chemical crosslinking agent include organic peroxides and polycondensation reaction products, and examples of the organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, alkyl peroxides, acyl peroxides, and peroxides. There are oxycarbonates and peroxyesters. Examples of the polycondensable reaction product include a coupling agent, vinyl silane is typical, and examples of the hydrolysis group include methoxy, ethoxy, acyloxy, amine, and chloro groups.

As the volatile foaming agent, those which have been conventionally used for producing an olefin resin foam can be used, and examples thereof include aliphatic hydrocarbons such as butane, propane and pentane, trichlorofluoromethane and dichlorodifluoro. Examples thereof include fluorinated aliphatic hydrocarbons such as methane, chlorodifluoromethane, trichlorofluoroethane, chlorodifluoroethane and hydrofluorocarbon, and chlorinated aliphatic hydrocarbons such as methyl chloride and methylene chloride.

A coating layer made of the same polyolefin resin as the resin coating layer according to claim 1 is laminated on the surface of the heat insulating cylinder by melt extrusion, and the surface of the coating layer according to any one of claims 1 to 3. It has been subjected to a texture treatment by the method of.

[0023]

Since the foamed resin tube used in the present invention is extruded and foamed into a tubular shape, there is no joint for molding into a tubular shape. Therefore, the joint may be broken by the air pressure fed when the tube is inserted. Absent.

According to the first aspect of the present invention, there is provided a pressing roll disposed immediately before or immediately after the seam of the adjacent pressing members, and at least either immediately before or immediately after passing through the seam. By pressing the surface, the resin coating layer that rises in a small gap between the seams of the pressing member is pushed inward, so that the coating resin does not stick out from the space between the seams of the pressing member to prevent fins. .

According to the second aspect of the present invention, since the endless belt is used as the pressing roll, the time for pressing the surface of the coated foamed resin tube becomes longer, and the graining effect becomes greater.

According to the third aspect of the present invention, immediately after the covered foamed resin tube has passed through the joint of the pressing member, the portion corresponding to the joint is locally heated and melted, and subsequently pressed by the pressing roll. Even if it occurs, it can be completely eliminated.

According to the fourth aspect of the invention, since the foam forming the heat insulating cylinder is manufactured by using the volatile foaming agent, ammonia, organic acid and the like generated during foaming remain in the foam. The copper tube does not corrode even if it is used for keeping heat of the copper tube. Further, the heat insulating cylinder of the present invention has an embossed surface, and by using a pressing roll or a pressing roll in combination with a heating tool, has a good appearance without fins.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the method for embossing a foamed resin tube coated with the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a perspective view showing an embodiment of the present invention as claimed in claim 1, in which the pressing roll 2 is arranged only immediately before the seam of the pressing member 20. FIG. 2 is a plan view of FIG. 1 and 2, an arrow, that is, a coated foamed resin tube 4 conveyed downward has a cross-sectional shape in which a circle having a diameter slightly smaller than the outer diameter of the resin coating layer is divided into four arcs, and the outer peripheral surface thereof. The press rolls 2 and 2 which are surrounded by four textured rolls 1, 1, 1 and 1 each having a textured surface 6, 6, and are formed immediately before the seam 7 between the adjacent rolls. 2, the surface of the coated foamed resin tube 4 immediately before passing through the seam 7 is pressed inward.

The pressing roll 2 is, as shown in FIG.
A disk 21 having a convex outer peripheral cross-section is pivotally supported by a support portion 22 provided at the tip of a handle 23, and the other end of the handle 23 is attached to a structure (not shown) by mounting holes 24, 24. ) Is attached.

FIG. 5 shows a processing apparatus for carrying out the method of the present invention. In this processing apparatus 3, a foaming mold 32 is provided on the outlet side of an extruder 31 for foamed resin tube material, and a covering resin 41 extruded from the extruder 33 is covered with a molding resin 34 on an extruded foamed resin tube 40. By coating with
The coated foamed resin tube 4 having the resin coating layer 41 is manufactured.

FIG. 6 is a sectional view showing the inside of the resin-coated mold 34, in which the molten coating resin 41 is discharged from an annular outlet 42 formed around the foamed resin tube 40 through a resin flow path, To be covered. Next, the coated foamed resin tube 4 is subjected to a graining process by a graining machine 5 having the configuration shown in FIGS. 1 and 2. 44 is a grain pattern.

The surface of the coated foamed resin tube 4 which has been textured by the above method is textured on the entire surface, and no fins due to the deformation of the resin coating layer 41 are formed, so that a high commercial value is obtained. Was given.

(Embodiment 2) FIG. 7 is a perspective view showing an embodiment of the present invention as defined in claim 3. In this embodiment, in the embossing machine 5 shown in FIG. 1, the covered foamed resin tube 4 is 10 m from the joint of the adjacent embossing rolls 1 and 1.
Hot air blower 8 placed immediately after coming out at a speed of / minute
The surface of the coated foamed resin tube 4 is locally melted by the hot air of 300 ° C. blown out from the thin nozzle 81 of FIG. By doing so, the fin generated by rising in the slight gap between the seams of the Chevy rolls 1 and 1 was melted, crushed, and completely disappeared.

(Embodiment 3) Next, an embodiment of the heat insulating cylinder according to claim 4 will be described. Crosslinkable low density polyethylene (19
Melt index 2.0 at 0 ° C, density 0.92
5) To 100 parts by weight, 0.1 part by weight of dibutyltin dilaurate as a crosslinking catalyst and 0.2 part by weight of talc as a cell nucleating agent were mixed, and a single screw extruder (bore diameter 70 mm, L / D = 3) was added.
0), melt kneading, and then volatile foaming agent (monochlorotetrafluoroethane) is injected from the foaming agent injection port provided in the center of the extruder to set the expansion ratio to 30 times and melt again. After kneading, the mixture was extruded into the atmosphere from a die (internal diameter 4 mm, circular slit having an outer diameter of 13 mm) mounted on the tip of the extruder and simultaneously foamed and crosslinked to form a crosslinked foam having an inner diameter of 8 mm and an outer diameter of 24 mm.

Next, low density polyethylene (melt index at 190 ° C. 3.
5, a density of 0.925) and a mixture of 100 parts by weight of a pigment and 0.05 parts by weight of a pigment, a single-screw extruder (bore diameter 40 mm, L /
D = 26), melted and kneaded, and then extruded in a tube shape having a thickness of 150 μm from a crosshead die attached to the tip of the extruder, and coated on the surface of the crosslinked foam to form a heat retaining tube.

Hot air was blown to the surface of the heat-retaining cylinder to heat the coating resin to a temperature higher than the melting temperature, and the surface of the heat-insulating cylinder was subjected to embossing using the embossing machine.

Comparative Example 1 Azodicarbonamide (pyrolysis type foaming agent) was blended with the same low density polyethylene as that used for the foam of Example 1, and this was mixed in an extruder at a temperature not higher than the decomposition temperature of the foaming agent. After melt-kneading, extruded into a sheet form from a slit die attached to the tip of the extruder, and irradiating this with an electron beam to crosslink the foamable sheet to foam and crosslink by foaming and crosslinking by heating above the decomposition temperature of the foaming agent. A crosslinked foamed sheet having a magnification of 30 times and a thickness of 4 mm was obtained by an atmospheric pressure foaming method.

Two pieces of the foamed sheet having a thickness of 4 mm were laminated by heat fusion to make a sheet having a thickness of 8 mm, and the same low-density polyethylene as the coating layer used in Example 1 was separately extrusion-molded on one surface of the foamed sheet. A film having a thickness of 100 μm and laminated by thermal lamination was rolled into a tube with the film side facing outward, and the edges were heat-sealed to obtain a heat insulating tube.

Comparative Example 2 Using the same crosslinked foam molded in Example 1, a separately manufactured electron beam crosslinked expanded polyethylene sheet (foaming ratio 30 times, thickness 3 mm) has a thickness of 100 μm on one side. A polyethylene film is overlaid, and a covering material that has been textured at the same time as pressurizing and heating is coated around the tubular crosslinked foam while heat-sealing, and the ends of the covering material are heat-sealed to form a heat insulating tube. Obtained.

The performance of the heat insulating cylinders obtained in Example 3 and Comparative Examples 2 to 3 was evaluated. The results are shown in Table 1.

[0041]

[Table 1]

*: Copper pipe corrosion evaluation method A copper pipe is set so that a heat medium can pass through, the surface of the copper pipe is covered with a foamed resin tube, and the medium heated to 90 to 100 ° C is poured into the copper pipe. The discoloration and corrosion state of the copper pipe in the portion covered with the coated foamed resin tube were observed over time.

As is clear from Table 1, since the heat retaining tube of Example 3 is not deformed, there is no gap even when a copper tube is inserted, and since it is manufactured by extrusion foaming into a tubular shape, it is fitted to the foamed body. There is no breakage. Further, since the volatile foaming agent is used, the copper pipe can be used for a long period of time without being corroded. However, in Comparative Example 1, since the decomposition type foaming agent was used, the corrosion of the copper pipe was prominent, and the foam had a joint, so that it was easily broken. Further, in Comparative Example 2, since a separately molded coating material is coated, it is easily deformed at that time, and therefore workability of inserting the copper pipe is not good.

[0044]

EFFECTS OF THE INVENTION The method of embossing a coated foamed resin tube of the present invention has the above-mentioned constitution, and since the foamed resin tube used in the invention of claims 1 to 4 is extruded into a cylindrical shape and foamed, it is formed into a cylindrical shape. There is no seam to do so that the seam does not break when inserting the tube.

According to the first aspect of the present invention, continuous wrinkling can be performed without causing fins due to the resin or the like coated on the surface of the coated foamed resin tube having the resin coating layer, As a result, a coated foamed resin tube having a high commercial value can be obtained.

According to the second aspect of the present invention, since the endless belt is used as the pressing roll, the time for pressing the surface of the coated foamed resin tube becomes longer, and the graining effect becomes greater.

In the third aspect of the present invention, immediately after the covered foamed resin tube has passed through the joint of the pressing member, the portion corresponding to the joint is heated and melted by a heating tool, and subsequently pressed by a pressing roll. Even if it occurs, it can be completely eliminated.

Further, in the heat insulating cylinder of the present invention according to claim 4, since the foam constituting the heat insulating cylinder is manufactured by using the volatile foaming agent, ammonia, organic acid or the like generated during foaming is produced. Does not remain in the foam, and the copper tube does not corrode when used as a heat insulator for the copper tube. In addition, the surface is embossed and has no fins and has a good appearance.

[0049]

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a method of embossing a coated foamed resin tube of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a perspective view showing an example of a press roll.

FIG. 4 is a perspective view showing another example of a pressing member.

FIG. 5 is an explanatory diagram for explaining an embodiment of the method of the present invention.

FIG. 6 is a cross-sectional view showing the inside of a resin-coated mold.

FIG. 7 is a perspective view showing another embodiment of the embossing method for the coated foamed resin tube of the present invention.

FIG. 8 is a sectional view showing a conventional covered foamed resin tube.

[Explanation of symbols]

 1: Shibo roll 2: Press roll 3: Processing device 4: Coated foamed resin tube 5: Wrinkle processing machine 6: Wrinkle mold surface 7: Seam 8: Heating tool 9: Winding roll 20: Pressing member 21: Disc 22 : Support part 23: Handle 24: Mounting hole 25: Pulley 27: Belt 34: Coated mold 40: Foamed resin tube 41: Resin coating layer 44: Texture pattern 81: Nozzle

Claims (4)

[Claims] 1. A coated foamed resin tube having a resin coating layer on its surface has a cross-sectional shape obtained by dividing a circle having a diameter slightly smaller than the outer diameter of the resin coating layer into two or more arcs, and has a grain pattern on the surface. A method for embossing a covered foamed resin tube, which is pressed by two or more pressing members, each of which is formed by a pressing roll arranged at least immediately before or immediately after the seam of the adjacent pressing members. A method for embossing a coated foamed resin tube, comprising pressing at least one surface of the coated foamed resin tube immediately before or after passing through an eye. 2. The method for embossing a coated foamed resin tube according to claim 1, wherein the pressing member is an endless belt. 3. A coated foamed resin tube having a resin coating layer on its surface has a cross-sectional shape in which a circle having a diameter slightly smaller than the outer diameter of the resin coating layer is divided into two or more arcs, and has a grain pattern on the surface. A method for embossing a covered foamed resin tube which is pressed by two or more pressing members formed by forming a heating tool arranged immediately after the seam of the adjoining pressing members and immediately after passing through the seam. The surface of the coated foamed resin tube is melted, and the softened or melted portion is pressed by a pressing roll arranged subsequent to the heating tool. 4. A coating layer comprising one layer of a polyolefin resin melt-extruded is provided on the outer peripheral surface of a cross-linked polyolefin resin foam extruded and molded into a cylindrical shape using a volatile foaming agent. A heat insulation tube, characterized in that the surface of the coating layer is subjected to texturing, and the texturing is carried out by the texturing method according to any one of claims 1 to 3.