KR101441037B1 - Insulation board - Google Patents

Abstract

The present invention discloses a method of manufacturing an insulating board for use in a cryogenic liquid storage system for storing and transporting cryogenic liquids such as liquefied natural gas. The present invention provides a rectangular box-shaped mold having cavities with open ends, and disposes the panel on the bottom of the cavity. A face plate having a releasability is attached to the inner surface of the cavity and a barrier is arranged at the open end. A cover plate covering the open end is mounted on the barrier wall, and a foam molding material is injected between the panel and the barrier wall to foam-form the heat insulating foam. The filling ratio of the free foaming density to the target density of the insulating foam is set to 1.3 or more. Further, after the heat-insulating foam is foam-molded, the heat-insulating foam is post-cured such that the panel, face plate, barrier and heat-insulating foam are cured simultaneously. The reinforcing fibers are inserted into the insulating foam or the reinforcing fibers are mixed with the foam molding material. According to the present invention, it is possible to improve the physical properties of the heat insulating board and to accurately manufacture the dimensions of the heat insulating board and improve the quality by manufacturing the heat insulating board by foaming and molding the foam molding material into a mold. In addition, since the heat insulating foam, the barrier wall, the panel and the face material are cured simultaneously, the manufacturing process is simplified, so that not only the productivity can be improved, but the physical properties can be prevented from changing and the life can be guaranteed.

Description

Manufacturing Method of Insulation Board {INSULATION BOARD}

The present invention relates to an insulating board, and more particularly, to a method of manufacturing an insulating board used in a cryogenic liquid storage system for storing and transporting cryogenic liquid such as liquefied natural gas.

Cryogenic liquids such as Liquefied Natural Gas (LNG), Liquid Argon, Liquid Nitrogen, and Liquid Oxygen are used in storage systems with an insulating structure to minimize evaporative losses. Stored or transported.

One example of a cryogenic liquid storage system is a cargo containment system for LNG carriers. Membrane type tanks with larger capacity and easier to manufacture than Spherical Type Tanks are preferred for storing and transporting cryogenic LNG at -165 ° C in LNG cargo holds. A gas transport system and a technigaz system developed by the company Gas Transport Et Technigaz (GTT, France) in France are used for the cooling system of the membrane type LNG carrier have. The Gaz Transport system is also referred to as GTT No96, and the Technigaz system is also referred to as the GTT Mark-III system.

U.S. Patent No. 7,540,395 entitled " Sealed wall structure and tank furnished with such a structure "discloses a structure and a construction method of a Technique system LNG carrier cargo hold. The Technigaz system disclosed in Korean Patent No. 10-1200019, "LNG Carrier" and Korean Patent No. 10-1168949, "Cryogenic Liquid Storage Tank", has a primary barrier, a primary panel, A primary insulation layer, a secondary barrier, a secondary insulation layer and a secondary panel.

Meanwhile, in the Technigaz system, the insulation foam constituting the secondary insulation layer is made of a reinforced polyurethane foam (RPUF) reinforced with a polyurethane foam (PUF) and a glass fiber mat ) Are used. RPUF improves fracture toughness of PUF in a cryogenic environment to prevent cracking due to temperature gradient.

A manufacturing method of the RPUF constituting the secondary insulation layer of the LNG carrier holding port is shown in Fig. 1 (a), the RPUF 10 includes a PUF 16 molded by foaming of polyols 12 and isocyanate 14, a reinforcing material 16 for reinforcing the PUF 16, And a continuous strand mat (20) inserted in the PUF (16).

The RPUF 10 is manufactured by free foaming (or continuous foaming) using a belt conveyor 30. A guide plate 32 is provided at an upper portion of the belt conveyor 30 at an interval from the belt conveyor 30 so as to form a space for foam molding of the RPUF 10. The continuous fiber mat 20 is wound on a feed reel 40 in the form of a roll. The continuous fiber mat 20 is unwound from the feed roll 40 and fed onto the belt conveyor 30. When the polyol 12 and the isocyanate 14 are mixed by the mixer 52 of the foam molding apparatus 50 and foamed on the belt conveyor 30, the continuous fiber mat 20 is formed while the PUF 14 is molded, So that the RPUF 10 reinforced by the RPUF 10 is manufactured.

Next, as shown in Fig. 1 (b), when the RPUF 10 is cured, the RPUF 10 is cut roughly larger than the required size by rough cutting. As shown in Fig. 1 (c), the roughly cut RPUF 10 is cut to the correct size. As shown in FIG. 1 (d), a secondary barrier 60 and a secondary panel 70 are bonded to the front surface and back surface of the RPUF 10 having an accurate size.

However, the conventional RPUF as described above has a problem that it is difficult to obtain uniform physical properties by free-foaming molding. In addition, since it is manufactured with slabstock foam which is produced by increasing the margin in the size of RPUF during foaming and cutting the portion having uniform physical properties in the after process, There is a problem in that the production cost rises. Particularly, during machining of RPUF, many micro cracks are generated at the machining site, which causes defects. Further, the manufacturing process of the RPUF is complicated and the productivity is deteriorated. There is a problem that the working environment is deteriorated by the dust and the wear of the tool which are generated when the RPUF is cut.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art. It is an object of the present invention to provide a method of manufacturing a new insulating board capable of improving the quality of a heat insulating board by manufacturing a heat insulating board using a mold.

It is another object of the present invention to provide a method of manufacturing an insulating board that can improve productivity because the heat-insulating foam, the barrier and the panel are co-cured to simplify the manufacturing process.

It is a further object of the present invention to provide a method of manufacturing a heat insulating board, in which faces are simultaneously cured on the surface of a heat insulating foam to prevent changes in physical properties and to ensure a service life.

According to an aspect of the present invention, a method of manufacturing an insulating board is provided. A method of manufacturing an insulating board according to the present invention includes the steps of: preparing a rectangular box-shaped mold having a cavity having an open end; Placing a panel on the bottom of the cavity; Attaching a face plate having releasability to the inner surface of the cavity; Placing a barrier at the open end; Mounting a cover plate over the barrier to cover the open end; And foam molding the insulation foam by injecting a foam molding material between the panel and the barrier so that the filling ratio of the free foam density to the target density of the insulation foam is 1.3 or more.

Further, the mold is preheated before foam molding of the heat insulating foam, and the heat insulating foam is post-cured so that the panel, the face material, the barrier and the heat insulating foam are cured simultaneously. Further, reinforcing fibers are inserted into the cavity so as to be inserted into the heat insulating foam or reinforcing fibers are mixed with the foam molding material.

The method for manufacturing the heat insulating board according to the present invention can improve the physical properties of the heat insulating board by accurately forming the heat insulating board and improving the quality by manufacturing the heat insulating board by foaming and molding the foam molding material into a mold. In addition, since the heat insulating foam, the barrier wall, the panel and the face material are cured simultaneously, the manufacturing process is simplified, so that not only the productivity can be improved, but the physical properties can be prevented from changing and the life can be guaranteed. Therefore, it can be usefully employed for manufacturing an insulation layer of a cryogenic liquid storage system such as a LNG carrier cargo hold.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view illustrating a method of manufacturing a conventional heat insulating board.
2 is a sectional view showing the construction of a heat insulating board manufactured by the method of manufacturing an insulating board according to the present invention.
3 is a view illustrating a method of manufacturing the heat insulating board according to the present invention.
4 is a view showing another example of a method of manufacturing the heat insulating board according to the present invention.
FIG. 5 is a photograph taken by a scanning electron microscope of RPUF of Example 1 manufactured by the method for manufacturing an insulating board according to the present invention and RPUF of Comparative Example 1 manufactured by conventional free-foaming molding.
6 is a photograph of the RPUF of Example 2 and the RPUF of Comparative Example 2, which are produced by the method of manufacturing the heat insulating board according to the present invention, by scanning electron microscopy.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments with reference to the accompanying drawings.

Hereinafter, preferred embodiments of a method of manufacturing an insulating board according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, a heat insulating board 100 manufactured by a method of manufacturing an insulating board according to the present invention includes a reinforcing fiber 114 on an insulation foam 110, for example, a PUF 112, And an RPUF 116 reinforced. In another embodiment, the heat insulating foam 110 may be formed of a polyvinyl chloride foam, a polystyrene foam, a micro-celluloid foam, a nano-celluloid foam, or the like. .

The reinforcing fiber 114 is composed of a glass fiber mat 114a. The reinforcing fiber 114 is a fiber mat made of a material such as carbon fiber, aramid fiber, polyester fiber, and polyvinyl acrylic fiber in addition to glass fiber Lt; / RTI >

A barrier 120 is attached to the surface of the RPUF 116. The barrier 120 is comprised of a triplex or metal sheet to be a secondary barrier of the LNG carrier cargo hold. The triplex consists of an aluminum foil bonded on both sides with a glass fiber composite. The metal sheet is made of a metal sheet made of stainless steel, aluminum, brass, zinc or the like. The panel 130 is attached to the back surface of the RPUF 116. [ The panel 130 is made of flywood or a sandwich panel to be a secondary panel of the LNG carrier cargo hold.

A face plate 140 is attached to the side surface of the RPUF 116. The face plate 140 not only reinforces the strength of the PUF 112 but also prevents a change in physical properties due to aging of the PUF 112 to ensure the life of the PUF 112. The face plate 140 is made of a polymer film 142. [ The polymer film 142 may be composed of a film having a releasing property, for example, a polytetrafluoroethylene (PTFE) film called Teflon. In addition, the face plate 140 may be made of an aluminum foil for reinforcement of strength.

Referring to FIGS. 2 and 3, the heat insulating board 100 according to the present invention is a mold foam manufactured by foam molding using a mold 150. The mold 150 has a cavity 154 formed with an open end 152 for foam molding and is formed in a rectangular box shape. A cover plate 160 is mounted on the top of the mold 150 so as to cover the open end 152. An injection hole 162 is formed at the center of the cover plate 160. A heater 170 is provided around the mold 150 as a pre-heating means of the mold 150.

The foaming material 118 is injected into the cavity 154 of the mold 150 by the foam molding apparatus 180 for foam molding of the heat insulating board 100 according to the present invention. The foam molding apparatus 180 mixes the polyol 118a and the isocyanate 118b for foaming molding of the foam molding material 118, for example, the PUF 112, into the cavity 154 of the mold 150 And a mixer 182 for injecting.

Hereinafter, a method of manufacturing the heat insulating board according to the present invention having such a structure will be described.

3, in a state in which the cavity 154 of the mold 150 is open, an operator places a panel 130 on the bottom of the cavity 154, that is, a plywood or the like serving as a secondary panel of the LNG carrier holding cargo Place the sandwich panel. The operator attaches the polymer film 142 to the inner wall surface of the cavity 154. After attaching the polymer film 142, the operator inserts the glass fiber mat 114a into the cavity 154 with the reinforcing fibers 114. The glass fiber mat 114a is inserted into the RPUF 116 so as to be adjacent to the back surface of the RPUF 116. However, May be injected into the bottom 154.

The operator places a triplex or stainless steel sheet that is the secondary barrier of the barrier 120, i.e., the LNG carrier hold, next to the open end 152. An injection hole 122 for injection of the foam molding material 118 is formed in the center of the barrier 120.

Next, after the barrier 120 is installed, the operator covers the open end 152 of the mold 150 on the cover plate 160. [ The injection hole 122 of the barrier 120 and the injection hole 162 of the cover plate 160 are in communication with each other. The mold 150 is preheated by the operation of the heater 170. By the preheating of the mold 150, the foamability of the PUF 112 is improved and the defective molding of the PUF 112 is prevented.

The polyol 118a and the isocyanate 118b are injected into the cavity 154 through the injection hole 162 of the cover plate 160 and the injection hole 122 of the barrier 120 by the operation of the foam molding machine 180. [ Lt; / RTI > The polyols 118a and the isocyanate 118b are foam-molded into the PUF 112 by an exothermic reaction. When the PUF 112 is cured by post-curing after the PUF 112 is foam molded, the barrier 120, the panel 130 and the polymer film 142 are simultaneously cured with the PUF 112 And is integrally joined to the PUF 112 by co-curing. The post curing can be achieved by heating the mold 150 by the operation of the heater 170. The PUF 112 is cross-linked by heat and hardened. In some embodiments, the insulating foam 110 may be cured by cooling after foaming.

When the hardening of the PUF 112 is completed, the operator opens the cover plate 160 and demolds the RPUF 116 from the cavity 154. At this time, the mold 150 and the RPUF 116 are smoothly released by the releasing property of the polymer film 142. As described above, since the RPUF 116 is manufactured by the foam molding using the mold 150, the dimensions of the RPUF 116 can be precisely adjusted. In addition, since the RPUF 116, the barrier 120 and the panel 130 are cured simultaneously, the manufacturing process is simplified, so that the production cost can be reduced and the productivity can be improved. Particularly, since the physical properties of the RPUF 116 are uniform, post-processing such as cutting is unnecessary.

4 shows another example of the method of manufacturing the heat insulating board according to the present invention. Referring to Fig. 4, in the manufacturing method of another example, the plurality of short fibers 114b are mixed with the foam molding material 118 by the mixer 182 with the reinforcing fibers 114 and foam-molded. Therefore, the short fibers 114a are uniformly distributed throughout the PUF 112 to reinforce the strength of the heat insulating board 100. In addition, the short fibers 114a can prevent cracks from being generated in the PUF 112, thereby improving the reliability of the heat insulating board 100.

On the other hand, when the heat insulating board 100 is manufactured using the mold 150, the PUF 112 is completely filled in the cavity 154 to prevent the filling failure, and the physical properties of the PUF 112 are uniform very important. The PUF of the insulation board used for the secondary insulation layer of the LNG carrier cargo holds is 120 kg / m3.

The ratio of the target density of the PUF to the free rise density is defined as the filling ratio of Equation 1 and the heat insulating board is manufactured while changing the filling ratio. As a result, the filling failure is prevented when the filling ratio is 1.3 or more, Uniform physical properties can be obtained.

FIG. 5 is a photograph of the PUF 112 manufactured by the method of manufacturing the heat insulating board according to the present invention and the PUF produced by the conventional free-foaming molding using a scanning electron microscope (SEM) 1, respectively. 5, the PUF of Example 1 is smaller than the PUF of Comparative Example 1 and the cell size is smaller and more compact. Therefore, it can be seen that the mechanical and thermal properties of the PUF of Example 1 are superior to those of the PUF of Comparative Example 1.

FIG. 6 shows PUF produced by the method of manufacturing an insulating board according to the present invention by scanning electron microscope to show Example 2 and Comparative Example 2. The filling ratio of the PUF of Example 2 is 1.9, and the filling ratio of the PUF of Comparative Example 2 is 1.2. 6, it can be seen that the physical properties of the PUF become uniform as the fill ratio increases. This is because the cell wall is buckled at the upper end of the mold in the PUF fabricated at a low filling ratio, but the shape of the cell is maintained in the case of the PUF fabricated at a high filling ratio.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: Insulation board 110: Insulation foam
112: PUF 114: reinforcing fiber
116: RPUF 118: foamed molding material
120: barrier 130: panel
140: face plate 150: mold
160: cover plate 170: heater
180: foam molding machine 182: mixer

Claims (7)

Comprising the steps of: preparing a rectangular box-shaped mold having a cavity having an open end;
Disposing a panel on the bottom of the cavity;
Attaching a face plate having releasability to the inner surface of the cavity;
Placing a barrier at said open end;
Mounting a cover plate over the barrier to cover the open end;
And foam molding the insulation foam by injecting a foam molding material between the panel and the barrier,
Wherein the filling ratio of the free foam density to the target density of the heat insulating foam is 1.3 or more. The method according to claim 1,
Further comprising the step of preheating the mold prior to foaming the insulating foam. The method according to claim 1,
Curing the heat insulating foam so that the panel, the face material, the barrier and the heat insulating foam are co-cured after the heat insulating foam is foam-molded. The method of claim 3,
Wherein the post-curing of the heat insulating foam is performed by heating the mold. 5. The method according to any one of claims 1 to 4,
Further comprising inserting reinforcing fibers into the cavity to be inserted into the heat insulating foam after the panel is disposed. 5. The method according to any one of claims 1 to 4,
Further comprising mixing reinforcing fibers in the foam molding material to be inserted into the heat insulating foam at the time of injection of the foam molding material. delete

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