JPH1058539A - Method for manufacturing hollow foam with crest - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a hollow foam with a crest for stably giving a uniform crest pattern without generating a superposition of a wrinkle and pattern of a surface film. SOLUTION: Before a pair of first crest rolls 13a, 13b and a pair of second crest rolls 14a, 14b perpendicular to the rolls 13a, 13b are sequentially pressed to a coating foam resin tube 9 covered with a surface film to transfer crest patterns formed on the respective rolls to the film, the tube 9 is introduced between two pairs of preliminary rolls 25a, 25b and 26a, 26b disposed at an angle of 45 deg. to the first and second crest rolls and disposed perpendicularly to one another of the pairs. These preliminary rolls are brought into pressure contact with the film thereby to cool and cure the film at the pressure contact portions. Thus, when the roll pairs are pressed from both the sides, wrinkles are prevented on the film, and simultaneously superposition of the crest patterns to be transferred by the crest rolls of the pairs is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hollow foam with a crest, which is used as a heat insulating material for piping of a hot water supply, a solar system, an air conditioner, etc., and more particularly, to a surface of a foamed resin tube covered with a surface film. In addition, the present invention relates to a method for producing a hollow foam with a pattern in which a pattern is formed by a pattern roll.

[0002]

2. Description of the Related Art Conventionally, as a heat retaining and protecting member for piping such as hot water supply, a solar system, and an air conditioner, a tube molded product made of a foamed resin such as highly crosslinked foamed polyethylene has been proposed.

[0003] In this type of tube molded product, in order to prevent the occurrence of bending wrinkles at the time of bending work, or to absorb wrinkles and make them less noticeable, the tube is further stretched or rubbed with a corner at the time of working. There is a demand for a product with a pattern in order to prevent the product from being torn or damaged.

In order to meet such demands, conventionally, in producing such a tube molded product, an embossed foamed resin sheet or an embossed foamed resin sheet with a surface film is formed into a tube shape. And a method in which the surface of an extruded foam tube is covered with an embossed foamed resin sheet or an embossed foamed resin sheet with a surface film.

However, when tubing a foamed resin sheet, there is a problem that the seam is formed on the surface and the strength is reduced. When the extruded foam tube is covered with the imprinted foamed resin sheet, if the dimensions of the extruded foamed tube and the imprinted foamed sheet do not completely match, the seam portion of the imprinted foamed sheet may be misaligned or may not be bonded. (Gap) occurs.

Therefore, in order to solve such a problem, a cross-sectional shape in which a circle having a diameter slightly smaller than the outer diameter of the coated foamed resin tube on which the surface film is adhered is divided into four arcs. Japanese Patent Laid-Open No. Hei 3-2076 discloses a printing method in which four rolls each having a patterned pattern formed on the surface thereof are simultaneously pressed against the surface of the coated foamed resin tube to transfer the patterned pattern onto the surface film.
No. 39 discloses this.

[0007] In addition, the film-coated foamed resin tube and the mesh member (sheet to which the pattern is applied) disposed outside the tube are curled through the round tube, so that a pattern is applied to the film-coated foamed tube. The method is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-88956.

[0008]

However, the conventional printing methods described in the above publications have the following problems.

That is, according to the method disclosed in Japanese Patent Application Laid-Open No. Hei 3-207639, the gap between the four imprint rolls,
In other words, since the clearance into which the coated foamed resin tube enters is constant, if the outer diameter of the coated foamed resin tube formed by coating the film on the surface changes, the sharpness of the pattern decreases, and uneven printing occurs. There's a problem. In addition, since it is difficult to uniformly compress the four portions of the coated foamed resin tube with the four imprint rolls, the imprint is likely to occur in the circumferential and longitudinal directions, resulting in a lack of stability.

[0010] On the other hand, the method disclosed in Japanese Patent Application Laid-Open No. 7-88956 has a problem that joints at both ends of the mesh body become unstable, and imprint defects remain in a band-like or streak-like shape. In addition, when passing through the round tube, if the outer diameter of the film-coated foam tube is small, the pattern will be unclear, and if it is large, the pattern will be clear. There is a problem that the foam tube is cut.

In view of the above-mentioned problems of the conventional method, the present inventor has already applied a surface film to a foamed tube and has a main purpose of preventing the occurrence of unevenness of a pattern. In the method for producing a crested hollow foam body in which a film is heated to perform a cresting process, a surface film-covered foamed resin tube is inserted between a pair of first crest rolls facing each other, and the first crest roll is placed on the surface. After transferring the pattern applied to the first pattern roll to the surface film by pressing against the film, the foamed resin tube is arranged orthogonal to the first pattern roll,
Further, the pattern imprinted on the second pattern roll is transferred to the surface film by inserting the second pattern roll between the opposing second pattern rolls and similarly pressing the second pattern roll against the surface film. , Proposed a method.

According to this proposed method, two pairs of pattern rolls whose arrangement directions are orthogonal to each other are individually pressed onto the foamed resin tube on which the surface film is adhered, and the pattern is transferred. Even if the outer diameter of the foamed resin tube coated with the surface film fluctuates, the first and second
By individually adjusting the pressing force of the pattern roll, the pattern can always be transferred with uniform sharpness.

However, according to the proposed method, although it is possible to prevent the occurrence of unevenness in the pattern, when the two pairs of pattern rolls are individually pressed against the tube, as shown schematically in FIG. The pair of imprint rolls R are pressed from the outside in the diametrical direction along the opposing direction and flattened, and the surface film is formed at the end of the flat area by the pressing (four circumferential positions of the tube T shown in FIG. 10E). It has been found that wrinkles are liable to occur, the product appearance lacks stability, and it is difficult to adjust when such a phenomenon occurs. The occurrence of wrinkles in the vicinity of the pressing end of such a pattern roll tends to be worse as the degree of compression by the pattern roll is larger, and the compression force is less likely to be absorbed as the pattern depth is smaller, and thus tends to worsen. Was found.

As a result of various studies, the present inventor has found that it is difficult to solve the problem of wrinkles which is likely to occur near the end of the tube by the above-mentioned proposed method. There is also a problem in appearance due to the overlapping of the patterns after passing through the second pair of pattern rolls, and it has been determined that it is difficult to solve this point as well, and as a result, the present invention has been achieved.

That is, an object of the present invention is to provide a method for producing a hollow foam with a crest, which can stably impart a beautiful pattern in appearance.

[0016]

According to the method for producing a hollow foam with a crest according to the present invention, a coated foamed resin tube having a surface film adhered is inserted between a pair of first crest rolls arranged opposite to each other. Then, after the first pattern roll is pressed against the surface film to transfer the pattern applied to the first pattern roll to the surface film, the foamed resin tube with the surface film is transferred to the first pattern roll. And a pair of second
The following steps are added to the manufacturing method of transferring the pattern applied to the second pattern roll onto the surface film by inserting the pattern between the pattern rolls and pressing the second pattern roll against the surface film. Achieves the above objectives.

That is, the coated foamed resin tube is
Before being inserted between the imprint rolls, it is introduced between two pairs of backup rolls and pressed against the surface film to lower the temperature of the surface film at the pressed portion. Here, each pair of the two pairs of backup rolls is composed of two opposing rolls, and each of the backup rolls is approximately 4 with respect to the first and second pattern rolls.
It is assumed that they are arranged at an angle of 5 °, and that each of these two pairs of backup rolls is arranged so as to be orthogonal to each other.

In the manufacturing method of the hollow foam with a crest according to the present invention, the substantial cresting is performed by covering the crests of the pair of first and second crest rolls which are orthogonal to each other, similarly to the above-mentioned proposed method. The transfer is performed by sequentially transferring to the surface of the foamed resin tube. Therefore, by individually adjusting the pressing force of the first and second pattern rolls, even if the outer dimensions of the coated foamed resin tube are changed, it is stable. It is possible to add a uniform pattern.

The generation of wrinkles on the surface film by individually pressing each pair of the imprint rolls onto the coated foam tube can be achieved by the two pairs of auxiliary rolls provided before the imprinting step using the first imprint roll in the present invention. Is prevented beforehand by the pressing process.

That is, the coated foamed resin tube is introduced between two pairs of auxiliary rolls, each of which is disposed at an angle of 45 ° with respect to the first and second pattern rolls, and each pair is orthogonal to each other. When a total of four preliminary rolls are pressed against the coated foamed resin tube, each preliminary roll is pressed against the cross-section of the coated foamed resin tube in a total of four locations in two directions orthogonal to each other, and the surface film in the pressed portion is cooled. On the surface film, a total of four line-shaped cured regions extending along the longitudinal direction of the tube are formed. The position in the circumferential direction of the tube of the cooling and hardening region of the surface film due to the press-contact of the preliminary roll matches the position of the flat end portion E shown in FIG. Therefore, by forming such a cooling and hardening region before the imprinting step using the first imprint roll, it is possible to prevent the surface film from being wrinkled at the flat end portion E by the imprint roll. At the same time, it is possible to prevent the patterns from being overlapped by the first and second pattern rolls.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a manufacturing apparatus for a hollow foam with a crest to which the present invention is applied, and FIG. 2 is a cross-sectional view of a coating mold 7 thereof.

The foamed resin tube 2 extruded into a cylindrical shape from the extruder 1 is once cooled to room temperature + 10 ° C. or lower, preferably room temperature, and then taken up by the take-up rolls 3a, 3b.

More specifically, the molding step of the foamed resin tube 2 by the extruder 1 is described, for example, by adding a cell nucleating agent, for example, talc to a cross-linked foamed polyethylene (M12.0) by 0.3%.
Parts, a crosslinking catalyst, for example, 0.1 g of dibutyltin dilaurate.
And 3.5 parts of a foam stabilizer, for example, stearic acid amide, are charged into an extruder 1 having a diameter of 90 mm and melted, and then volatile foam is injected from an injection port 1a opened in the middle of the extruder 1. Agent (eg, halogenated hydrocarbon HCFC-
142b / HCFC-22, 6: 4) was press-fitted in an amount equivalent to 28 times the expansion ratio, kneaded and cooled.
Is foamed into a cylindrical shape at the same time as discharge through a predetermined die attached to the tip of the above, to obtain a foamed resin tube (extruded cross-linked foamed polyethylene tube) 2 having an inner diameter of 9 mm and an outer diameter of 24.5 mm.

The foamed resin tube 2 thus obtained is introduced into a coating die (crosshead die) 7 by take-off rolls 5a and 5b. A discharge port of an extruder 6 is connected to the coating die 7, and as shown in FIG. 2, the molten resin A supplied from the extruder 6 is applied to the outer peripheral surface of the foamed resin tube 2 by the coating die 7. It is extruded in a cylindrical shape so as to cover it, is adhered to the outer peripheral surface of the foamed resin tube 2 as a surface film 8, and is a foamed resin tube 9 with a surface film as shown in a schematic sectional view in FIG. 9).

The material of the resin A to be the surface film 8 is, for example, linear low-density polyethylene (M12, density 0.
925) can be suitably used. The coated foamed resin tube 9 obtained as described above is once cooled by a water-cooled shower (not shown) placed immediately after the coating mold 7 and then introduced into the embossing machine 10.

FIG. 4 shows a schematic overall configuration diagram (A) of the embossing machine 10 and a BB sectional view (B) thereof. In the embossing machine 10, the coated foamed resin tube 9 is first passed through a heating machine 12 equipped with a heating dryer 11, and has a surface temperature of 70 ° C to 150 ° C, preferably a surface film 8 and a foamed resin. ± 3 with respect to the melting point of tube 2
After being heated to a temperature range of 0 ° C., it is introduced between two pairs of preliminary rolls 25a and 25b and between 26a and 26b. Here, each spare roll 25a, 25b, 2
A cooling pipe (not shown) through which cold water passes is inserted in the center of each of 6a and 26b in order to prevent a temperature rise due to heat storage.

Each of the preliminary rolls 25a and 25b, and 26
a and 26b are first pattern rolls 13a to be described later, respectively.
13b and the second imprint rolls 14a and 14b at an angle of 45 °, and each pair of spare rolls, ie a pair of 25a and 25b, and 26a
And the pair of 26b are arranged so as to be orthogonal to each other, and these preliminary rolls 25a, 25b and 26a, 26b are pressed against the surface of the coated foam resin tube 9 by pressing. By pressing the two pairs of preliminary rolls 25a and 25b and 26a and 26b, the surface film 8 at the pressed portion is cooled and hardened.

That is, the coated foamed resin tube 9 is passed through two pairs of auxiliary rolls, and as shown in a partial sectional perspective view of FIG. A total of four line-shaped cured regions 27a to 27d extending in the longitudinal direction are formed. The positions of the hardened regions 27a to 27d in the circumferential direction of the tube 9 are positions obtained by equally dividing the circumference into four.

Here, the width w of each of the cured regions 27a to 27d
Is preferably 1 to 3 mm. When the width w is less than 1 mm, the effect of preventing the occurrence of wrinkles at the flat end portion by a later-described pattern roll is poor. When the width w exceeds 3 mm, wrinkles are easily generated at the flat end portion. It is also noticeable in appearance. That is, the degree of compression by each spare roll (the outer diameter of the tube at the roll pressing portion in the pressed state of the roll / the outer diameter before pressing) is preferably 0.9 to 0.95.

Each of the preliminary rolls 25a, 25b,
On the surfaces of 26a and 26b, it is desirable to provide an appropriate uneven pattern in order to improve the adhesion between the surface film 8 and the foamed resin tube 2 or to improve the appearance design.

Further, each of the preliminary rolls 25a, 25b, 26
a and 26b may be driven to rotate at a constant speed or may not be driven. Now, the coated foamed resin tube 9 having the above-described cured regions 27a to 27d formed on the surface film 8 is then placed between the pair of first pattern rolls 13a and 13b each having a pattern formed on each of the cylindrical surfaces. And these pattern rolls 13 a and 13 b are pressed against the coated foamed resin tube 9. The first crest roll 13a,
13b are arranged to face each other in parallel to each other, and in this example, they are respectively arranged along the vertical axis. The degree of compression by the first pattern rolls 13a, 13b is 0.2 to
0.8 is preferable, and 0.4 to 0.75 is more preferable. By the pressing of the first pattern rolls 13a and 13b, the surface film 8 of the coated foamed resin tube 9 is
On the left and right sides of the cross section of the tube 9, specifically, in relation to the four hardened areas 27 a to 27 d shown in FIG.
The pattern of the pattern rolls 13a and 13b is transferred to the area between 7d.

Thereafter, the coated foamed resin tube 9 is heated by a plurality of heating dryers 17a and 17b, and then disposed opposite to each other, and a pair of second pattern rolls 14a having a pattern formed on each of the cylindrical surfaces. , 14b, and these rolls 14a, 14b are pressed against the surface of the coated foamed resin tube 9. The second pattern rolls 14a and 14b are positioned approximately 50 mm to 300 mm downstream of the first pattern rolls 13a and 13b in a posture orthogonal to the first pattern rolls 13a and 13b, that is, in this example, respectively. They are arranged along a horizontal axis.
The preferable range of the degree of compression by the second pattern rolls 14a and 14b is the same as that of the first pattern rolls 13a and 13b. Due to the pressing of the second pattern rolls 14a and 14b, the top surface film 8 of the coated foamed resin tube 9 has a predetermined area on both the upper and lower sides of the cross section of the tube 9, that is, FIG.
In the relationship between the four hardened regions 27a to 27d shown in the above, the region between 27b and 27c, and 27d and 2
The pattern of the pattern rolls 14a and 14b is transferred to the area between 7a. At this time, the first pattern rolls 13a, 13b
The cross-section of the coated foamed resin tube 9 which has been flattened to some extent by the pressing of the second printing rolls 14a and 14b is returned to a circular shape by the pressing of the second pattern rolls 14a and 14b.

The coated foamed resin tube 9 that has passed through the second pattern rolls 14a and 14b is in a state where a pattern is provided over the entire surface. Here, the first pattern roll 13
a, 13b and the second imprint rolls 14a, 14b press the coated foamed resin tube 9 with each roll 1
Since the hardened areas 27a to 27d of the surface film 8 are already formed at the flat end portions by the pressing of 3a, 13b or 14a, 14b, wrinkles do not occur in those portions, and at the same time, the first and second portions are not formed. The pattern transferred by the pattern roll does not overlap with each other.

The first and second pattern rolls 13a, 13a,
Cooling pipes 15a, 15b and 16a, 16b through which cold water passes are also passed through central portions of 13b, 14a, and 14b to prevent a rise in temperature due to heat storage.

The coated foamed resin tube 9 on which the pattern is transferred to the entire surface via the second pattern rolls 14a and 14b,
Water is cooled by a water-cooled cooler 18 to prevent the occurrence of a pattern flow. The coated foamed resin tube with a crest, which has been cooled through the cooler 18, that is, the hollow foam 19 with a crest, is taken up by a pair of take-up rolls 20 a and 20 b and continuously taken up by the take-up machine 12.

The cooler 18 may be provided with a water supply pipe 18a for supplying cold water and a water-cooled shower 18b at the upper part, and a drain pipe 18c for discharging cold water at the lower part. The cooler 18 may be of an air-cooled type.

The first and second pattern rolls 13a, 13a,
The pattern transferred by 13b and 14a, 14b is not particularly limited, but an example is shown in an enlarged sectional view in FIG. 6, and FIGS. 7A and 7B are plan views. The example of a pattern is shown.

It should be noted in the above embodiment of the present invention that the coated foamed resin tube 9 has a pair of first
And the second crest rolls 13a, 13b, 14b and 14b,
Since the imprint pattern is transferred by being individually pressed, even if the outer diameter of the coated foamed resin tube 9 fluctuates, the outer diameter fluctuation can be obtained by independently adjusting the pressing force of each pair of the imprint rolls. Is easy to deal with, and a uniform and stable pattern can always be provided.

Further, in the above-described embodiment of the present invention, it should be noted that, prior to the printing process using the two pairs of pattern rolls, the flat end portion corresponding to the pressing of the two pairs of pattern rolls is used. Is to be cooled and hardened by pressing two pairs of preliminary rolls arranged at an angle of 45 ° with respect to these two pairs of imprint rolls. It is possible to prevent wrinkles from occurring at the flat end portion, and also to prevent overlapping of the imprint patterns transferred by the two pairs of imprint rolls.

Here, the shape of each spare roll is not only the shape shown in FIG. 4B, but also a portion of a cylindrical surface having a larger diameter than other portions as shown in FIG. 8A. And 25 'in which a concave and convex pattern is provided in a predetermined region sandwiching the maximum diameter of the drum-shaped roll as shown in FIG. Of course, any shape can be used as long as it can fulfill the function of the understood preliminary roll.

The first and second imprint rolls are also cylindrical in shape as in the above-described embodiment. In addition, as shown in FIG. 13, 13 'or the like may be used.

[0042]

As described above, according to the present invention, a pair of first imprint rolls and a pair of second imprint rolls arranged orthogonal to the first imprint rolls are provided with a surface film. In transferring the pattern of each pattern roll to the surface film by individually pressing the coated foamed resin tube, 45 ° is applied to each of these pattern rolls before the patterning step by these pattern rolls. The coated foamed resin tube is introduced between two pairs of auxiliary rolls arranged at an angle and each pair is arranged so as to be orthogonal to each other, and the auxiliary rolls are pressed against each other, so that the pressed portion of the pressed portion is formed. Since the surface film is cooled and hardened, in the imprinting step by each imprint roll, the surface film in the area corresponding to the flat end of the tube due to the pressing of each imprint roll has already been hardened. On purpose made, without wrinkles at the time of pressing the crest rolls, also, it does not occur overlap crest pattern transferred by fingerprint rolls of each pair.

Therefore, according to the present invention, by individually adjusting the pressing force by the first and second pattern rolls, it is possible to easily cope with the fluctuation of the outer diameter of the coated foamed resin tube, and to stably reduce the outer diameter. A clear and crisp pattern can be attached to the surface film, and wrinkles do not occur on the surface film due to the pressing of each pair of pattern rolls. A foam can be easily obtained.

Further, according to the present invention, the apparatus configuration can be made more compact as compared with the known conventional method, and the generation of particle burrs can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a manufacturing apparatus of a hollow foam with a crest to which the present invention is applied.

FIG. 2 is a sectional view of the coating mold 7;

FIG. 3 is a schematic sectional view of a coated foamed resin tube 9 obtained by a coated mold 7 of FIG.

FIG. 4 is a schematic overall configuration diagram (A) of the boss processing machine 10 in FIG. 1 and a cross-sectional view thereof along BB (B).

FIG. 5 shows two pairs of auxiliary rolls 25a, 25b, 26a, 2
Partial cross-sectional perspective view of the coated foamed resin tube 9 that has passed through 6b

FIG. 6 is an enlarged cross-sectional view showing an example of a pattern transferred by first and second pattern rolls 13a and 13b and 14a and 14b.

FIG. 7 also shows first and second pattern rolls 13a, 13
FIG. 3B is a diagram showing an example of a pattern printed by the print patterns b and 14a and 14b in a plan view.

FIG. 8 is an explanatory diagram of another example of the shape of the preliminary roll used in the present invention.

FIG. 9 is an explanatory diagram of another example of the first and second pattern rolls used in the present invention.

FIG. 10 is a schematic explanatory view of wrinkles generated on a surface film in a conventional proposed method of individually pressing two pairs of pattern rolls onto a tube.

[Explanation of symbols]

1,6 Extruder 2 Foamed resin tube 7 Coating mold 8 Surface film 9 Coated foamed resin tube 10 Embossing machine 11,17a, 17b Heat dryer 12 Heater 13,13 'Crest roll 13a, 13b First crest roll 14a , 14b Second crest roll 18 Cooler 19 Crested hollow foam 21 Winder 25, 25 ', 25a, 25b, 26a, 26b Preliminary roll 27a, 27b, 27c, 27d Line-shaped curing area

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B29L 23:00

Claims (1)

[Claims] 1. A method for producing a crested hollow foam body, comprising applying a surface film to a foamed resin tube, heating the surface film, and cresting the surface film.
The coated foamed resin tube on which the surface film is adhered is inserted between a pair of first pattern rolls arranged opposite to each other, and the first pattern roll is pressed against the surface film to thereby form the first film. After transferring the imprint pattern applied to the imprint roll to the surface film, the coated foamed resin tube is disposed at right angles to the first imprint roll, and a pair of second imprint rolls arranged opposite to each other. A method of transferring a pattern applied to the second pattern roll to the surface film by inserting the second pattern roll into the surface film by pressing the second pattern roll against the surface film. Before being inserted between the first imprint rolls, each is arranged at an angle of approximately 45 ° with respect to the first and second imprint rolls, and each pair is orthogonal to each other. By introducing between the two pairs of spare rolls that are placed and pressing each spare roll against the surface film, the temperature of the surface film in the pressed portion is reduced, and Production method.