JP2016102580A - Heat insulation cover and manufacturing method of heat insulation cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat insulation cover capable of covering the whole periphery of a heat insulation object while using a vacuum heat insulation material in a protective manner, and a manufacturing method of the heat insulation cover.SOLUTION: In a heat insulation cover covering the periphery of a heat insulation object 1, split covers 2 are formed so as to be split into a plurality of ones in a circumferential direction of the heat insulation object 1; in order to constitute the respective split covers 2, a plate-like vacuum heat insulation material 5 is provided along or substantially along the surface shape of the heat insulation object 1; a first foam polyurethane layer 6 is attached to the outside surface of the vacuum heat insulation material 5; a second foam polyurethane layer 7 is attached to the inside surface of the vacuum heat insulation material 5; and the whole circumferential surface of the vacuum heat insulation material 5 is surrounded by the first foam polyurethane layer 6 and the second foam polyurethane layer 7 to integrate them.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat insulating cover that covers the periphery of a heat retaining object and a method for manufacturing the heat insulating cover.

  Conventionally, for example, low-temperature pipes, low-temperature equipment, particularly heat insulation covers used in pipe cold insulation work related to LNG and LPG, are generally mainly made of polyurethane foam over the past 30 years. The performance is said to be limited to a thermal conductivity of about 0.02 W / mK at a normal temperature of 23 ° C. (see Patent Document 1).

JP 2001-108189 A

The conventional heat insulating cover described above needs to be thickened in order to reduce the amount of heat dissipated.
However, it is difficult to increase the construction thickness of the heat insulating cover without a margin space at the construction site, and there is a limit.
On the other hand, it is considered to use a vacuum heat insulating material with very good heat insulating performance, but the vacuum heat insulating material is usually inside a bag-like mat formed by a resin film in which a metal layer is laminated, Spacer member is provided to form a sealed space, and air is excluded from the sealed space. The vacuum insulation material alone has poor heat insulation at the periphery of the bag-like mat and is effective in covering the object to be kept warm. It is difficult to form the vacuum heat insulating material in a shape along the outer peripheral surface of the heat insulation object when there is a problem that the heat insulation area cannot be increased, or the outer peripheral surface of the heat insulation object has a complicated shape, for example.
Further, there is a weak point such that the bag-like mat is damaged due to contact with other objects during or after the heat insulation construction, the vacuum state inside is destroyed (vacuum breakage), and the heat insulation performance is rapidly lowered.
Therefore, a plate-shaped vacuum heat insulating material is integrally molded inside or outside the cover molded with foamed polyurethane, and on the surface of the vacuum heat insulating material opposite to the foamed polyurethane layer, FRP or the like for protection It is conceivable to prevent the vacuum insulation material from being broken by contact with other objects by bonding the fiber reinforced resin plate.
However, in this case, not only does the work of bonding with the adhesive take a lot of work, but air bubbles are likely to be mixed between the surface of the vacuum heat insulating material and the fiber reinforced resin plate, or gaps are likely to occur. Air bubbles such as bubbles and gaps swelled and the appearance deteriorates, and water vapor and moisture enter the air layer from the outside, resulting in a decrease in heat insulation performance.

  Accordingly, an object of the present invention is to provide a heat insulating cover that can solve the above-mentioned problems and can cover the entire periphery of the heat insulation object while using the vacuum heat insulating material in a protected state, and a method for manufacturing the heat insulating cover. By the way.

  The characteristic configuration of the first heat insulating cover of the present invention is a heat insulating cover covering the periphery of the heat insulation object, and is divided into a plurality of pieces in the circumferential direction of the heat insulation object to form a divided cover, and the divided cover To constitute each, a plate-like vacuum heat insulating material along or substantially along the surface shape of the heat retaining object is provided, and a first foamed polyurethane layer is attached to the outer surface of the vacuum heat insulating material, and A second foamed polyurethane layer is attached to the inner side surface of the vacuum heat insulating material, and the entire peripheral surface of the vacuum heat insulating material is surrounded and integrated by the first foamed polyurethane layer and the second foamed polyurethane layer.

According to the first characteristic configuration of the present invention, a first foamed polyurethane layer is provided on the outer side surface of the vacuum heat insulating material, and a second foamed polyurethane layer is provided on the inner side surface of the vacuum heat insulating material, whereby the vacuum heat insulating material is provided. Since the entire circumferential surface of the material is surrounded and integrated by the first foamed polyurethane layer and the second foamed polyurethane layer, a plurality of divided covers are combined in the circumferential direction of the heat retaining object to cover the heat retaining object. When doing, the foaming polyurethane layer protects the weak point part where the heat insulation property of the peripheral part of a vacuum heat insulating material falls, and can maintain high heat insulation performance as a whole.
Moreover, even if the outer peripheral surface of the heat insulation object has a complicated shape, and the vacuum heat insulating material that insulates it is difficult to process the complicated shape, the second foamed polyurethane layer surrounding the vacuum heat insulating material is The heat insulating object can be easily molded into a shape along the outer peripheral surface of the heat insulating object, and the heat insulating object can be covered without a gap, and the first foamed polyurethane layer attached to the outer surface of the vacuum heat insulating material is also provided on the outer surface of the vacuum heat insulating material. Familiarity and easy integration make it possible to form and maintain a good external shape.
In addition, since the entire peripheral surface of the vacuum heat insulating material is surrounded by the first foamed polyurethane layer and the second foamed polyurethane layer, contact between the vacuum heat insulating material and other objects during and after the heat insulating work can be avoided. The vacuum heat insulating performance of the vacuum heat insulating material can be maintained for a long time.
Therefore, the heat insulation target can be insulated and protected with high heat insulation performance.

  According to a second characteristic configuration of the present invention, the vacuum heat insulating material forms a sealed space by arranging a spacer member inside a bag-like mat formed of a resin film in which a metal layer is laminated. Air is excluded, and a waterproof layer or a moisture-proof layer is provided on the outer periphery of each of the first foamed polyurethane layer and the second foamed polyurethane layer.

  According to the second characteristic configuration of the present invention, in addition to being able to achieve the above-described operational effects according to the first characteristic configuration of the present invention, the first foaming polyurethane layer and the second foaming are formed by the waterproof layer or the moisture-proof layer. Since the outer peripheral portion of the polyurethane layer is protected, it is possible to prevent moisture and water vapor from entering the first and second foamed polyurethane layers from the outside. For this reason, the periphery of the bag-like mat forming the vacuum heat insulating material The first and second polyurethane foam layers can surely exhibit and maintain the heat insulation and heat-retaining function in the portion having weak heat insulation performance.

  According to a third characteristic configuration of the present invention, the first foamed polyurethane layer and the second foamed polyurethane layer are formed in separate steps.

According to the third characteristic configuration of the present invention, since the first foamed polyurethane layer and the second foamed polyurethane layer are formed in separate steps, when the divided cover is molded, a substantially central portion within the thickness thereof is formed. It becomes easy to arrange and fix the vacuum heat insulating material. That is, for example, if the first foamed polyurethane layer and the second foamed polyurethane layer are to be formed simultaneously, the vacuum heat insulation is performed with the space for foaming of each urethane stock solution secured on both front and back sides of the vacuum heat insulating material. In addition, the foaming pressure of each urethane stock solution and the expansion flow of the urethane stock solution during foaming are not necessarily the same. For this reason, different foams are used on the front and back surfaces of the vacuum insulation material. It is difficult to place and fix the vacuum insulation material in a stable posture and shape within the wall thickness of the insulation cover due to deformation and movement of the vacuum insulation material due to the pressure and the pressing force based on the expansion flow of the urethane stock solution In addition, the wraparound flow of the urethane stock solution around the edge of the vacuum heat insulating material was not performed sufficiently, and voids such as voids were generated at the peripheral edge of the heat insulating cover, leading to a decrease in heat insulating performance. There is a possibility that the problem is likely to occur.
In contrast, if the first foamed polyurethane layer and the second foamed polyurethane layer are formed in separate steps, only one foamed space is secured when either the first foamed polyurethane layer or the second foamed polyurethane layer is formed. Deformation of the vacuum insulation material by fixing the vacuum insulation material and backing up to support the vacuum insulation material in the foaming space on the other side against the pressure based on the foaming pressure and expansion flow of the urethane stock solution In addition, it is possible to stably prevent the movement of the urethane stock solution by the foaming flow of the urethane stock solution to the corners around the end of the vacuum heat insulating material.
Therefore, it is easy to prevent the vacuum heat insulating material from coming into contact with other objects at the time of construction and after construction without lowering the heat insulation performance of the peripheral portion of the heat insulation cover, and it is possible to provide a heat insulation cover with high heat insulation performance.

  According to a fourth characteristic configuration of the present invention, the heat retaining object is a fluid circulation pipe, the divided cover is formed of a partial cylindrical body divided in a circumferential direction of the fluid circulation pipe, and the vacuum heat insulating material is , Along the arc direction of the divided cover and in the shape of a partial cylinder along the longitudinal direction of the pipe, and by surrounding the fluid circulation pipe with a plurality of the divided covers, the periphery of the fluid circulation pipe The vacuum heat insulating material is formed so as to surround it.

  According to the fourth characteristic configuration of the present invention, the vacuum heat insulating material formed in the partial cylindrical shape is stable within the wall thickness of the divided cover formed in the partial cylindrical body, in order to insulate and keep the fluid circulation pipe thermally insulated. Therefore, just by surrounding the fluid circulation pipe with a plurality of divided covers, the periphery of the fluid circulation pipe can be insulated and kept warm with the effective heat insulation area of the vacuum heat insulating material increased.

  The characteristic structure of the manufacturing method of the 5th heat insulation cover of this invention is the 1st formwork which provided the concave surface part equivalent or substantially equivalent to the outer peripheral surface of the said division | segmentation cover inside, and the outer peripheral surface of the said thermal insulation target object. A second mold having a convex surface portion equivalent to or substantially equivalent to a part thereof is prepared, and the divided mold cover is wrapped by combining the first mold and the second mold. First, a small piece of foamed polyurethane foam having a height equal to or substantially the same as the thickness of the first foamed polyurethane layer is formed on the concave surface portion of the first formwork so that a coverable cover forming space can be formed. A first step of disposing a plurality of spacers in a state of being separated from each other; a second step of placing the vacuum heat insulating material on the plurality of first polyurethane foam spacers; and the top of the vacuum heat insulating material. And a thickness equivalent to or substantially equivalent to the second foamed polyurethane layer And a third step of placing a second spacer having a size capable of covering the entire inner surface of the vacuum heat insulating material, the first mold formed by the foamed polyurethane first spacer, and the vacuum heat insulation. A fourth step of injecting an unfoamed polyurethane stock solution into the first space between the materials and foam-curing the polyurethane stock solution in the divided cover forming space by combining the first mold frame and the second mold frame. And a second step of separating the first mold and the second mold to remove the second spacer, and the second mold formed by combining the first mold and the second mold again. A sixth step of injecting an unfoamed polyurethane stock solution into the second space between the mold and the vacuum heat insulating material, and between the first mold and the second mold after the polyurethane stock solution is foam-cured. From the split cover forming space of the split cover It is in place and a seventh step of taking out the over.

According to the fifth characteristic configuration of the present invention, the vacuum heat insulating material is floated at a certain distance from the concave surface portion of the first mold frame in the divided cover forming space by the first step and the second step. It can arrange | position stably and can inject | pour unfoamed polyurethane stock solution into the 1st space between a 1st mold and a vacuum heat insulating material.
Further, the third step and the fourth step prevent the unfoamed polyurethane undiluted solution from entering the second space between the vacuum heat insulating material and the second mold frame, and the gap between the first mold frame and the vacuum heat insulating material. The polyurethane stock solution injected into the first space can be uniformly foamed and filled, while the vacuum insulation material can be prevented from being displaced due to the foaming pressure of the polyurethane stock solution. The formed first polyurethane foam layer is self-adhered integrally.
In the sixth step after the fifth step, the second foamed polyurethane layer is formed inside the vacuum heat insulating material, and the vacuum heat insulating material and the second polyurethane layer are self-adhered during urethane foaming.
Finally, by the seventh step, the divided cover is taken out from the first mold frame and the second mold frame, and can be provided as a heat insulating cover for the heat retaining object.

  According to a sixth characteristic configuration of the present invention, the first polyurethane polyurethane spacer is cut out from molded polyurethane foam.

  According to the sixth feature of the present invention, the first polyurethane foam spacer can be easily formed by cutting out from the molded foam polyurethane, and the first foam polyurethane layer integrated by foaming of the polyurethane stock solution and self-adhesion is provided. Easy to form.

  According to a seventh feature of the present invention, before injecting the unfoamed polyurethane stock solution, a waterproof or moisture-proof first sheet is temporarily fixed to the concave surface portion of the first mold, and the first A waterproof or moisture-proof second sheet is temporarily fixed to the convex surface portion of the two-frame.

  According to the seventh characteristic configuration of the present invention, before injecting the unfoamed polyurethane stock solution, temporarily fixing a waterproof or moisture-proof first sheet to the concave surface portion of the first mold, By temporarily fixing a waterproof or moisture-proof second sheet to the convex surface portion of the second mold, the waterproof or moisture-proof first sheet and the waterproof or moisture-proof second sheet are provided. A split cover that is integrally bonded to the outer peripheral surface can be easily formed, and a heat insulating cover that has good waterproofness or moisture resistance and is easy to maintain heat insulating performance can be formed.

It is a disassembled perspective view before the assembly construction of the heat insulation cover attached with respect to a heat retention object. It is a perspective view after the assembly construction of the heat insulation cover with respect to a heat retention object. It is radial direction sectional drawing of a division | segmentation cover. FIG. 4 is an end radial direction sectional view of the divided cover, (a) is an enlarged view of FIG. 3, and (b) is an end radial direction sectional view of the divided cover when there is a seal portion around the bag-like mat. . (A) is radial direction sectional drawing of the 1st formwork of a 1st process, (b) is a perspective view of a 1st process. (A) is radial direction sectional drawing of the 1st formwork of a 2nd process, (b) is a perspective view of a 2nd process. (A) is radial direction sectional drawing of the 1st moldwork of the 3rd, 4th process, (b) is a perspective view of the 3rd, 4th process. (A) is radial direction sectional drawing of the 1st, 2nd moldwork of a 6th process, (b) is a perspective view of a 6th process. (A) is radial direction sectional drawing of the 1st formwork of a 7th process, (b) is a perspective view of a 7th process. It is assembly | attachment sectional drawing of the heat insulation cover of another embodiment. It is an assembly perspective view of the heat insulation cover of another embodiment. It is the assembly | attachment longitudinal cross-sectional view of the heat insulation cover of another embodiment.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1, 2, 3, and 4 (a), for example, a heat insulating cover for a fluid circulation pipe as a heat retaining object 1 is configured.
That is, the semi-cylindrical divided cover 2 is formed by dividing into two in the circumferential direction of the fluid circulation pipe.
Each of the divided covers 2 is provided with a spacer member 4 inside a bag-like mat 3 formed of a resin film laminated with a metal layer such as an aluminum foil to form a sealed space, and air is excluded from the sealed space. Then, a semi-cylindrical plate-like vacuum heat insulating material 5 along or substantially along the surface shape of the fluid circulation pipe is provided, and the first foamed polyurethane layer 6 is attached to the outer surface of the vacuum heat insulating material 5; A second foamed polyurethane layer 7 is provided on the inner side surface of the vacuum heat insulating material 5, and the entire peripheral surface of the vacuum heat insulating material 5 is surrounded by the first foamed polyurethane layer 6 and the second foamed polyurethane layer 7. The first and second foamed polyurethane layers 7 are integrated by the self-adhesive force of urethane when forming.
In addition, asphalt felt is bonded as a waterproof layer 8 to the surface different from the bonding surface with the vacuum heat insulating material 5 in the first and second foamed polyurethane layers 6 and 7, and moisture from the outside to the foamed polyurethane layer. Intrusion of water is prevented and deterioration of heat insulation performance is prevented.
The waterproof layer 8 should be at least waterproof, but if an aluminum foil laminate sheet is used, the waterproof layer 8 has not only waterproofness but also moisture resistance, and can prevent water vapor from entering outside of moisture from the outside. As a function can be expected.

(Second embodiment)
As shown in FIG. 11, a pair of first divided covers 2A and a pair of second divided covers 2B, in which a heat insulating cover is doubled on the outside of the heat insulation object 1 made of piping and the piping is doubled, are divided. The positions of the joint joints at the circumferential ends of the covers are arranged differently to prevent heat leakage from the joint joint, and on the first sheet 8A of the first divided cover 2A located outside. Uses a highly waterproof and moisture-proof aluminum laminate sheet, and the second sheet 8B of the first divided cover 2A and the first sheet 8A and the second sheet 8B of the second divided cover 2B are breathable. In addition, by using asphalt felt that is waterproof, intrusion of dew condensation water generated in the pipe periphery while preventing intrusion of water vapor and water from the atmosphere with the aluminum laminate sheet of the first sheet 8A, Scan asphalt felt are to be able to stop in.

(Production method)
A method for manufacturing each of the divided covers 2 will be described in the following order of steps as shown in FIGS.
1. A first mold 10 having a semi-cylindrical concave surface portion 9 that is the same as or substantially equivalent to the outer peripheral surface of the divided cover 2 and a semi-cylindrical shape that is equivalent or substantially equivalent to a part of the outer peripheral surface of the fluid circulation pipe. The first mold 10 and the second mold 12 are prepared by preparing the second mold 12 having the convex surface portion 11 on the inner side and combining the first mold 10 and the second mold 12. 12, a split cover forming space capable of covering the semi-cylindrical split cover 2 can be formed freely.
Asphalt felt is installed on the concave surface portion 9 inside the first mold 10 as the first sheet 8A for forming the waterproof layer 8, and the height is equal to or approximately the same as the thickness of the first foamed polyurethane layer 6. The first polyurethane foam spacers 13 (40 mm thick) having a thermal conductivity of 0.024 W / mK in small pieces are formed by cutting out from the molded foam polyurethane, and the first spacers 13 are separated from each other. A first step of arranging a plurality of the asphalt felts disposed on the concave surface portion 9 of the mold 1 in a state of being separated from each other so as to be fixed via a one-component rubber adhesive (FIG. 5 (a)). ), (B)).
The first spacer 13 may have a flat shape, but the front and back surfaces are curved along the concave surface 9 of the curved first mold 10, and the vacuum heat insulating material 5 is stably held in position. In this case, the first mold 10 is used to cut out a foam-molded one having the same curvature as the first mold 10.

2. In order to form a vacuum space by filling the inside of the bag-like mat 3 formed of a resin film laminated with aluminum foil with a spacer member 4 made of glass fiber to eliminate air from the internal space of the bag-like mat 3. The entire periphery is sealed to form a sealed space. A second step of placing the vacuum heat insulating material 5 (thickness 10 mm) having a thermal conductivity of 0.0025 W / mK constituted by the bag-like mat 3 on the plurality of first polyurethane foam spacers 13 (FIG. 6A ), (B)).
Note that the vacuum heat insulating material 5 is bent in advance into a partially cylindrical plate shape along or substantially along the surface shape of the fluid circulation pipe, and when the flange-like seal portion 14 is present in the entire peripheral portion. As shown in FIG. 4 (b), it is folded inward so that it does not protrude from the periphery of the split cover 2.

3. A semicircular arc-shaped second spacer 15 having a thickness equal to or substantially the same as the second foamed polyurethane layer 7 and capable of covering the entire inner surface of the vacuum heat insulating material 5 is previously molded from foamed polyurethane. Then, the 3rd process (FIG. 7 (a), (b)) mounted on the vacuum heat insulating material 5. FIG.
Note that a release material is applied to the periphery of the second spacer 15.

4). An unfoamed polyurethane undiluted solution is injected into the first space between the first mold 10 formed by the first polyurethane foam spacer 13 and the vacuum heat insulating material 5, and the first mold 10 and the second mold 12. And the polyurethane undiluted solution is heated at 30 to 35 ° C. for 45 minutes to 50 minutes in a split cover forming space partially having an air escape portion, and then foamed and cured in a fourth step (FIG. 7 (a ), (B)).
A release paper 16 is attached to the convex surface portion 11 of the second mold 12 so that the second spacer 15 does not adhere to the second mold 12 in advance by foaming polyurethane.

5. A fifth step of separating the first mold 10 and the second mold 12 to remove the release paper 16 from the second mold 12 and removing the second spacer 15 from the inside of the semi-cylindrical vacuum heat insulating material 5. .

6). Asphalt felt is temporarily attached to the convex surface portion 11 of the second mold 12 as the second sheet 8B for forming the waterproof layer 8, and the first mold 10 and the second mold 12 are combined again. A sixth step of injecting an unfoamed polyurethane stock solution into the second space between the second mold 12 and the vacuum heat insulating material 5 (FIGS. 8A and 8B).
The second mold 12 is provided with a mounting portion 17 for temporarily fixing the release paper 16 and the second sheet 8B.

7. Heat to 30 to 35 ° C. for 45 to 50 minutes, and after foaming and curing the polyurethane stock solution, from the divided cover forming space between the first mold 10 and the second mold 12 to a thickness of about 100 mm The molded divided cover 2 is taken out, and the circumferential end and the longitudinal end of the divided cover 2 are cut off to a predetermined size (FIG. 9A, FIG. 9B). )).

[Another embodiment]
Other embodiments will be described below.
<1> As the heat retaining object 1, not only a fluid circulation pipe but also a cylindrical fluid storage tank, a valve connected to the pipe, or the like may be a target. In addition to being divided into two parts in the direction, the divided cover 2 can be easily formed by dividing it into three or more parts. Moreover, in order to keep the temperature of the object to be kept warm, the heat insulation includes the cold preservation, and the relative temperature difference from the outside air may be a positive value or a negative value, and both cases are included. . For example, the fluid flowing through the fluid distribution pipe includes both a warm fluid and a cold fluid.
<2> In order to constitute the vacuum heat insulating material 5, an inorganic powder or the like other than glass fiber may be used as the spacer member 4 provided in the bag-like mat 3. That is, it is only necessary to secure a vacuum space.
<3> A plurality of the vacuum heat insulating materials 5 may be stacked and embedded in the divided cover 2.
<4> When the divided cover 2 covers the entire peripheral surface of the heat retaining object 1 such as piping by a plurality of combinations, as shown in FIG. 10, the fitting portion at the edge in the circumferential direction of the divided cover 2 In this case, the plurality of vacuum heat insulating materials 5 may be arranged so as to be polymerized in the radial direction and integrally molded with the polyurethane foam layer to reduce heat leakage as much as possible to improve the heat insulating performance.
<5> The plurality of divided covers 2 have a longitudinal section cut along the longitudinal direction of the pipe, as shown in FIG. If adjacent parts are fitted together so that the ends of the vacuum heat insulating material 5 overlap each other in the radial direction, if the interior is within the wall thickness of the split cover 2, further heat in the longitudinal direction of the pipe Leakage is prevented and heat insulation performance is improved.
<6> In order to fix the first spacer 13 to the asphalt felt or the vacuum heat insulating material 5, in addition to the rubber adhesive, a urethane adhesive may be used.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

2 Divided Cover 3 Bag-shaped Mat 4 Spacer Member 5 Vacuum Heat Insulating Material 6 First Foam Polyurethane Layer 7 Second Foam Polyurethane Layer 8 Waterproof Layer 8A First Waterproof Layer Forming Sheet 8B Second Waterproof Layer Forming Sheet 9 Concave Surface 10 1st formwork 11 Convex surface part 12 2nd formwork 13 1st spacer 15 2nd spacer

Claims (7)

A heat insulating cover that covers the periphery of the heat insulation object,
Dividing into multiple pieces in the circumferential direction of the heat retaining object to form a divided cover,
To configure each of the divided covers,
While providing a plate-like vacuum heat insulating material along or substantially along the surface shape of the heat retaining object,
A first foamed polyurethane layer is provided on the outer side surface of the vacuum heat insulating material, and a second foamed polyurethane layer is provided on the inner side surface of the vacuum heat insulating material, and the entire peripheral surface of the vacuum heat insulating material is provided on the first foamed polyurethane layer. A heat insulating cover surrounded and integrated with the second foamed polyurethane layer.   The vacuum heat insulating material is a bag-like mat formed of a resin film in which a metal layer is laminated, a spacer member is provided to form a sealed space, and air is excluded from the sealed space, The heat-insulating cover according to claim 1, wherein a waterproof layer or a moisture-proof layer is provided on the outer peripheral portion of each of the first foamed polyurethane layer and the second foamed polyurethane layer.   The heat insulating cover according to claim 1 or 2, wherein the first foamed polyurethane layer and the second foamed polyurethane layer are formed in separate steps. The heat retaining object is a fluid circulation pipe,
The divided cover is composed of a partial cylindrical body divided in the circumferential direction of the fluid circulation pipe, and the vacuum heat insulating material is formed in a partial cylindrical shape along the arc direction of the divided cover and along the longitudinal direction of the pipe. The said heat insulation pipe | tube is formed so that the said vacuum heat insulating material may surround the circumference | surroundings of the said fluid circulation piping by enclosing with the said some division | segmentation cover with respect to the said fluid circulation piping. The heat insulation cover of Claim 1. It is a manufacturing method of the heat insulation cover according to claim 1,
A first mold frame provided with a concave surface portion 9 that is the same as or substantially equivalent to the outer peripheral surface of the divided cover, and a convex surface portion 11 that is equivalent or substantially equivalent to a part of the outer peripheral surface of the heat retaining object. By preparing the second mold frame provided and combining the first mold frame 10 and the second mold frame, it is possible to freely form a split cover forming space capable of covering the split cover,
A plurality of small first polyurethane foam spacers having a height equal to or substantially the same as the thickness of the first foamed polyurethane layer are provided on the concave surface portion 9 of the first mold frame so that they are spaced apart from each other. A first step of arranging;
A second step of placing the vacuum heat insulating material on a plurality of foamed polyurethane first spacers;
A third step of placing on the vacuum heat insulating material a second spacer having a thickness equivalent to or substantially equal to the second foamed polyurethane layer and capable of covering the entire inner surface of the vacuum heat insulating material. When,
An unfoamed polyurethane undiluted solution is injected into a first space between the first mold frame formed by the first polyurethane foam spacer and the vacuum heat insulating material, and the first mold frame and the second mold frame And a fourth step of foaming and curing the polyurethane stock solution in the divided cover forming space,
A fifth step of removing the second spacer by separating the first mold and the second mold;
A sixth step of injecting an unfoamed polyurethane undiluted solution into a second space between the second mold frame and the vacuum heat insulating material formed by combining the first mold frame and the second mold frame again; ,
And a seventh step of removing the divided cover from the divided cover forming space between the first mold and the second mold after the polyurethane stock solution is foam-cured.   The method for manufacturing a heat insulating cover according to claim 5, wherein the first spacer made of foamed polyurethane is cut out from molded foamed polyurethane.   Before injecting the unfoamed polyurethane stock solution, a waterproof or moisture-proof first sheet is temporarily fixed to the concave surface portion of the first mold and waterproofed to the convex surface portion of the second mold The manufacturing method of the heat insulation cover of Claim 5 or 6 which temporarily fixes the property or moisture proof 2nd sheet | seat.

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