KR101386204B1 - Apparatus for forming article having hollowness using two sheet, and forming methods using the apparatus - Google Patents

Abstract

According to the present invention, a molded article having a hollow part therein can be made by vacuum molding two foam sheets in a closed system, which is characterized by being lightweight and excellent in thermal insulation.

Description

Apparatus for forming article having hollowness using two sheet, and forming methods using the apparatus}

The present invention relates to a molding apparatus, and more particularly to an apparatus for manufacturing a molded article having a hollow portion therein using two foam sheets. In addition, the present invention also relates to a molding method using such a molding apparatus.

Molded articles having hollows therein may be produced by blow molding a thermoplastic resin such as polyethylene. Representative examples of moldings having hollows therein include air ducts provided in automobiles.

The blow molding is disclosed in US Pat. No. 5,527,51 and the like. However, solid type products made by blow molding polyethylene are disadvantageous for use in automobiles and the like because their density is about 1 g / cm ³ and heavy. That is, since the product is heavy, it adversely affects automobile fuel economy.

In addition, the solid-type product manufactured by the blow molding has a problem of increasing carbon dioxide emissions of the vehicle because the condensation phenomenon of water occurs when the air duct is used as an air duct and the cooling and heating efficiency is lowered. In order to solve this problem, the nonwoven fabric is attached to the outer surface of the solid air duct to improve the insulation and reduce the noise, but the weight is still a problem, and the manufacturing process such as the nonwoven fabric is added. There is a problem.

In order to solve the above problems, the present inventors have, through long experience and research, heated two foam sheets (for example, crosslinked polyethylene foam sheets) disposed at the upper and lower sides by using a heater and hot air. Then, a method of manufacturing a molded article (eg, an air duct for a vehicle) having a hollow therein was developed by vacuum molding using upper and lower molds and trimming the edge portion.

By using the above manufacturing method, it is possible to make a light car air duct, which contributes to the weight reduction of the car and the like and can improve the fuel economy of the car.

In addition, since the molded article (for example, an air duct for an automobile) made according to the manufacturing method has excellent thermal insulation, it is possible to improve the heating and cooling efficiency of the automobile by minimizing the heat loss of the cold and warm air transferred to the interior of the vehicle. Accordingly, by reducing the carbon dioxide emissions of the car, it is possible to reduce the fuel consumption loss of the car due to heating and cooling. In addition, due to such excellent heat insulating properties, almost no condensation occurs, and it is not necessary to employ a separate auxiliary heat insulating material such as a nonwoven fabric.

The present invention is directed to an apparatus capable of automating such a manufacturing method. Specifically, the present invention is a process for mounting and conveying two foam sheets, the process of heating the conveyed foam sheet using a heater and injecting hot air or room temperature air into the space between the two foam sheets A process of making a molding by moving the upper and lower molds to make a space between two foam sheets into a closed system and vacuum molding, supplying cooling air to the hollow of the molding, and cooling the trimming knife ( The aim is to provide a device that can automate the process of cutting the edges of the molding by operating a trimming knife.

Another object of the present invention is to provide a molding method using such a molding apparatus.

The apparatus according to the present invention to achieve the above object, the upper mold and the lower mold; It is installed in the space (s1) between the upper mold and the lower mold, the front end 16 is open to have a 'c' shape, has a top surface 11 and the bottom surface 13, the frame formed with a through hole in the center ; Moving means for selectively moving the seats 1 and 2 mounted on the upper surface 11 and the lower surface 13, respectively; A heater capable of reciprocating to the space s1 and heating the seats 1 and 2; And cylinders for pressurizing the upper and lower sides of the frame, for pressing the sheets 1 and 2 against the frame to bring the sheets 1 and 2 into close contact with the frame.

The upper mold has a first recess 31 to vacuum suction the seat 1 mounted on the upper surface 11, and the lower mold has a vacuum suction on the seat 2 mounted on the lower surface 13. It has a second recess 41. The upper mold and the lower mold are molded articles having a hollow portion v therein by vacuum suctioning the sheets 1 and 2 in a state in which a closed system is made by pressing the sheets 1 and 2 mounted on the upper and lower surfaces. Make

The tip 16 of the frame may have an inclined surface 12. Among the pressurizing cylinders, the pressurizing cylinder installed to correspond to the front end 16 includes a pressurizing block 51 having an inclined surface 53 that mates with the inclined surface 12. When the pressing block 51 presses the tip 16, the inclined surfaces 12 and 53 may cooperate with each other to press the sheets 1 and 2.

The pressing block 51 may have a horizontal surface 54 extending horizontally from the end of the inclined surface 53.

The moving means includes: a track installed at both sides of the frame in the longitudinal direction of the frame and rotating in an orbit; And a needle part installed in the track and inserted into the seat (1) (2). The seats 1 and 2 can move by moving the track in the state where the needle part is inserted into the seats 1 and 2.

The trajectory of the moving means is preferably such that the seat (1) (2) and the frame is in close contact with the needle portion is inserted into the seat (1) (2). The frame is a nozzle (17) for supplying hot air or air at room temperature to the seat (1) (2) mounted on the upper and lower surfaces, and the closed space (s2) formed by the frame, the pressurizing cylinder and the moving means. ) Can be installed.

The upper mold includes one of the trimming knife and the groove around the first concave portion 31, and the lower mold includes the other of the trimming knife and the groove around the second recess 41. do. The trimming knife and the groove correspond to the edges of the molding, and the edge of the molding is cut by inserting the trimming knife into the groove after the molding of the molding is molded.

The molding apparatus according to the present invention may be vacuum-molded while supplying air to a space made by the first and second recesses by using a nozzle after making a closed system.

The heater, the upper heater 20 installed on the upper surface (11); And a lower heater 25 installed below the lower surface 13.

According to another aspect of the present invention, the molding method includes: (a) mounting the sheets 1 and 2 on the upper and lower surfaces 11 and 13 of the frame having the tip 16 open and having a 'c' shape. step; (b) Pressing the seats 1 and 2 against the frame using at least a pressurizing cylinder installed so as to correspond to the rear end 19 and the front end 16 of the frame to securely fix the seats 1 and 2 to the frame. Making; (c) heating the sheet (1) (2) using a heater; And (d) forming a closed system by moving the upper mold and the lower mold to pressurize the sheets 1 and 2 to form a closed system, and vacuum forming the sheets 1 and 2 to form a molding having a hollow part v formed therein. Making; includes.

Step (c) may include inflating the sheet by injecting hot air into the space s2 formed by the sheets 1 and 2 and the frame and the pressurizing cylinder.

The step (d) may include cooling the molding by injecting cooling air into the hollow part (v).

After the step (d), it may further comprise the step of cutting the edge of the molding by operating the trimming knife mounted on any one of the upper mold and the lower mold.

It is preferable that the said sheets 1 and 2 are foam sheets.

The present invention has the following effects.

First, a molding with a hollow part can be made by vacuum forming two foam sheets in a closed system.

Second, the manufacturing process of the molding can be automated.

Third, by pressing the sheet by using a pressure block having an inclined surface 12 at the tip of the frame and having an inclined surface 53 to match the inclined surface 12, the stroke of the pressure block is reduced and the seat 1 The problem that (2) is folded at right angles can be solved.

Fourth, by forming a closed space (s2) by using the frame, the moving means and the pressure block, injecting hot air into the space (s2) by inflating the sheet (1) (2) can be easily made vacuum forming have. Accordingly, the thickness variation of the molding may be reduced, the productivity may be increased, and the folding failure may be reduced.

Fifth, it is possible to make a molded article having a light and excellent thermal insulation, for example, an air duct for a vehicle having a light and excellent thermal insulation.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention. And should not be construed as limiting.
1 is a plan view showing a molding apparatus according to a preferred embodiment of the present invention.
Figure 2 is a front view showing that the seat is mounted on the frame provided in the molding apparatus of FIG.
3 is a plan view showing that the sheet is mounted on the frame provided in the molding apparatus of FIG.
Figure 4 is a cross-sectional view showing a pressing cylinder for pressing the frame provided in the molding apparatus of FIG.
5 is a front view showing that the upper and lower molds provided in the molding apparatus of FIG.
FIG. 6 is a front view showing a part of a trimming knife provided in the upper mold of FIG. 1; FIG.
7 is a plan view showing a molded article produced by the molding apparatus of FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

1 is a plan view showing a molding apparatus according to a preferred embodiment of the present invention, Figure 2 is a front view showing that the seat is mounted on the frame of the molding apparatus.

Referring to the drawings, the molding apparatus includes a frame 10 for mounting the sheets 1, 2, a moving means for moving the sheets 1, 2 mounted on the frame 10, the sheets 1, 2 Heater 20 (25) for heating), upper mold 30 and the lower mold 40, and the pressurizing cylinder 50 for pressing the sheet (1) (2) against the frame (10).

The frame 10 is installed in a space (s1 in Fig. 4) between the upper and lower dies 30, The frame 10 is opened at its tip end 16 and has a "C" shape. The front end 16 is opened to allow the sheet 1 and 2 to move forward after molding is completed.

The frame 10 has an upper surface 11, a lower surface 13, a tube 15 formed at the center, and a nozzle 17. Although a rectangular frame having a 'c' shape is shown in the figure, the frame may have various structures according to the shape of a molding to be molded, such as a circle or an oval, if one side is an open structure.

As shown in Figs. 2 and 3, the frame 10 has an inclined surface 12 at its tip. The inclined surface 12 has a structure mating with the inclined surface 53 of the pressurizing cylinder 50 and cooperates with each other to fix the seats 1 and 2 in close contact. Accordingly, the pressure cylinder 50 is operated so that the inclined surface 53 presses the sheets 1 and 2 against the inclined surface 12 so that the space s2 between the sheets 1 and 2 can be sealed. This point is further explained below. It is preferable that the slopes 12 and 53 have an inclination of about 45 degrees.

The inclined surface 12 forms the inclined surface 12, as compared with the case in which the front surface 16 forms a vertical surface, the sealing property of the space (s2 in FIG. 4) is improved and the stroke of the cylinder 50 for pressurization is increased. It is possible to increase the productivity by reducing the distance that the block 51 is moved up and down, and there is an advantage of preventing the sheet (1) (2) is folded at a right angle.

The passage (15) is formed to penetrate the frame (10). Accordingly, as shown in FIG. 5, the upper and lower dies 30 and 40 can be in close contact with each other to form a closed system.

The nozzle 17 injects air into the space s2 formed by the seats 1, 2, the frame 10, and the pressure blocks 51, 52. The air injected through the nozzle 17 causes the sheet 1 of the upper surface 11 to swell up and the sheet 2 of the lower surface 13 to swell downward so that vacuum forming is performed well. In case of not injecting air, the sheet 1 of the upper surface 11 is squeezed down, and there is a problem in that the thickness variation of the vacuum-molded molding is increased. However, by injecting air, the sheet 1 of the upper surface 11 is inflated. Productivity can be increased by making vacuum forming well.

Air at room temperature may be injected into the space s2 through the nozzle 17, but air of high temperature, preferably about 80 to 130 degrees, may be injected. The hot air can shorten the heating time by the heaters 20 and 25 by heating the sheets 1 and 2.

On the other hand, the present invention can be used a variety of foam sheet, in the case of making the air duct for the vehicle of the present invention may be used foam sheet of crosslinked polypropylene crosslinked polypropylene by electron beam irradiation.

The moving means are provided on the upper side and the lower side of the frame 10, respectively. The moving means is provided with a trajectory 60 provided on both sides of the frame 10 and a needle portion 62 provided so as to protrude from the trajectory 60.

The trajectory 60 is provided on both sides 18 of the frame 10 in the longitudinal direction of the frame 10 and is rotated in an endless track by a drive motor (not shown).

With the needle part 62 inserted into the seats 1 and 2, the raceway 60 can bring the seats 1 and 2 into close contact with the frame 10, whereby the space s2 is It can be sealed. Since the trajectory 60 is rotated in an endless track by a motor or the like, it is a commonly used constitution, and a detailed description thereof will be omitted.

Needle part 62 is a pointed portion formed so that it can be inserted into the sheet (1) (2), when the track 60 is rotated is inserted into the sheet (1) (2) flowing into the frame 10 The seats 1 and 2 are moved, and after completion of molding, the raceway 60 is rotated so that the seats 1 and 2 are moved out of the seats 1 and 2.

The heaters 20 and 25 may be installed on one side of the upper and lower dies 30 and 40. [ The heaters 20 and 25 are capable of reciprocating with respect to the space s1. That is, when the seats 1 and 2 are moved by the moving means to be mounted on the frame 10, and the seats 1 and 2 are brought into close contact with the frame 10 by the pressure cylinder 50, the heater 20. After 25 moves to the space s1 to heat the sheets 1 and 2, it returns to the original position. In addition to the heating, hot air may be injected through the nozzle 17.

The movement of the heaters 20 and 25 may be performed by a cylinder (not shown in the drawing) or a motor (not shown in the figure), and this will be easily understood by those skilled in the art, Description thereof will be omitted.

The heaters 20 and 25 may include an upper heater 20 disposed on the upper surface 11 and a lower heater 25 disposed below the lower surface 13. The upper heater 20 heats the sheet 1 provided on the upper surface 11, and the lower heater 25 heats the sheet 2 provided on the lower surface 13.

As the heaters 20 and 25, an infrared heater and a halogen heater having a wavelength of about 1.5 mu m may be used, but the present invention is not limited thereto.

The upper and lower molds 30 and 40 are reciprocated vertically by a cylinder (not shown). That is, as described above, when the heaters 20 and 25 move to the space s1 to heat the sheets 1 and 2, and then the heaters 20 and 25 retreat to their original positions, the upper mold 30 is lowered and lower mold 40 is raised to press seats 1 and 2 to form a closed system, as shown in FIG.

The upper mold 30 is provided with a first recessed portion 31, a trimming knife 33, and a suction pipe 35.

The first recess 31 is a portion formed to be recessed in the lower surface of the upper mold 30, and is a space for inflating the sheet 1 by vacuum suction.

The trimming knife 33 is installed around the first yaw groove 31 in the upper mold 30 so as to be movable up and down by a vertically movable cylinder (not shown). The edge of the molding is cut by lowering the trimming knife 33 to be inserted into the groove 43 of the lower mold 40. The structure in which the trimming knife 33 is moved up and down by the cylinder will be easily understood by those skilled in the art, and therefore, a description thereof will be omitted.

The suction pipe 35 is a pipe connected to an external vacuum pump (not shown). When the vacuum pump is operated after the upper and lower molds 30 and 40 form a closed system, the sheet 1 is inflated upwards to be in close contact with the surface of the first recess 31 and the sheet 2 is struck down. The hollow part v is formed by being in close contact with the surface of the second recess 41.

The lower mold 40 has a second recessed portion 41, a groove 43, and a suction pipe 45.

The second recess 41 is a portion formed to be recessed in the upper surface of the lower mold 40, and is a space for vacuum suctioning the sheet 2 to swell downward.

The groove 43 is formed around the second recessed groove 41 on the upper surface of the lower mold 40 and has a shape in which at least a part of the trimming knife 33 can be inserted.

The suction pipe 45 is connected to an external vacuum pump (not shown) and has the same structure and function as the suction pipe 35 described above.

The first and second recesses 31 and 41 have a structure and a shape determined according to the shape of the molding to be molded. Although the first and second recessed grooves 31 and 41 are shown as ellipses in the figure, the shape formed by the first and second recessed grooves 31 and 41 is not limited to this, Square, and the like.

The trimming knife 33 is provided on the upper mold 30 and the groove 43 is formed on the lower mold 40. However, when the trimming knife is installed on the lower mold 40, The grooves may be formed.

As shown in Fig. 6, it is preferable that the trimming knife 33 is formed by repeatedly forming the mountain 33a and the valley 33b. When the trimming knife 33 having such a structure is inserted into the groove 43, the sheets 1 and 2 are cut at predetermined intervals. That is, as shown in Fig. 7, the cutting grooves 3 are formed at predetermined intervals by the trimming knife 33 around the molded product f. The cutting groove 3 facilitates later separation of the molding f from the sheets 1, 2.

The pressurizing cylinder 50 is installed so as to correspond to the front end 16 and the rear end 19 of the frame 10. The pressurizing cylinder 50 presses the seats 1 and 2 against the front end 16 and the rear end 19 so that the space formed by the seats 1 and 2 and the frame 10 and the moving means ( seal s2).

The pressurizing cylinder (50) has press blocks (51) (52) provided at its end. The pressing block 51 provided so as to correspond to the front end 16 of the frame 10 has the inclined surface 53. [

More preferably, the pressing block 51 has a horizontal surface 54 formed to extend from the end of the inclined surface 53. When the pressure block 51 of the upper and lower pressure cylinders 50 is operated to press the seats 1 and 2, the horizontal surface 54 prevents the air in the space s2 from leaking to the outside. do.

Then, a process of manufacturing a molded article using the molding apparatus according to the present invention will be described.

First, foam sheets 1 and 2 are prepared. Examples of the foam sheets (1) and (2) include foam sheets of crosslinked polypropylene in which polypropylene is crosslinked by electron beam irradiation. The sheets 1 and 2 are moved to the rotor frame 10 by a feeding part (not shown in the figure, by moving the sheet using a roller or the like). The movement is carried out by a moving means. The seats 1 and 2 are moved by the rotation of the trajectory 60 while the needle part 62 is inserted into the seats 1 and 2. At this time, the track 60 preferably adheres the seats 1 and 2 to the frame 10.

Subsequently, the pressurizing cylinder 50 is operated to press the seats 1 and 2 against the frame 10 so as to press the press blocks 51 and 52 and the raceway 60 and the seats 1 and 2 and the frame. The space s2 is sealed by (10). Following the operation of the pressurizing cylinder 50 or with the operation, the heaters 20 and 25 advance into the space s1 and then heat up the sheets 1 and 2.

At this time, when the air is injected through the nozzle 17, the sheet 1 is inflated upward and the sheet 2 is inflated downward, which is advantageous for the subsequent vacuum forming operation. Specifically, since the sheets 1 and 2 are inflated, the thickness variation and the folding failure of the vacuum-molded molding f can be reduced and the productivity can be increased.

On the other hand, when the hot air, for example, 80 degrees to 130 degrees of air is injected through the nozzle 17, the sheet 1 by the heaters 20 and 25 is also effective because the sheet 1 and 2 are heated. (2) Heating time can be shortened and productivity can be improved.

When the heating is completed, the heaters (20) and (25) are returned to the home position.

Then, the upper and lower molds 30 and 40 are moved so that the upper and lower molds 30 and 40 press the sheets 1 and 2 so that a closed system is formed.

Next, a vacuum pump (not shown in the figure) is operated to inflate the sheet 1 upward and to inflate the sheet 2 downward. After the vacuum forming, the cooling air can be injected through the nozzle 17. The cooling air shortens the process time by cooling the molding f.

Then, the trimming knife 33 is operated to cut the edge of the molding f.

When the cutting is completed, the pressure cylinder 50 is returned to its original position, and the seats 1 and 2 are advanced by one pitch using the moving means. Since the frame 10 has a 'c' shape in which the front end 16 is open, the molding f may be moved forward.

As the sheets 1 and 2 advance by one pitch, a new portion of the sheets 1 and 2 is positioned in the frame 10.

1, 2: sheet 10: frame
20: upper heater 25: lower heater
30: upper mold 40: lower mold
50: pressurizing cylinder 60: orbital
62: Needle portion

Claims (16)

Upper mold and lower mold;
It is installed in the space (s1) between the upper mold and the lower mold, the front end 16 is open to have a 'c' shape, has a top surface 11 and the bottom surface 13, the frame formed with a through hole in the center ;
Moving means for selectively moving the seats 1 and 2 mounted on the upper surface 11 and the lower surface 13, respectively;
A heater capable of reciprocating to the space s1 and heating the seats 1 and 2; And
It is provided in the upper and lower sides of a frame, Comprising: The press cylinder which presses the sheet | seat 1 and 2 against a frame, and adheres the sheet | seat 1 and 2 to a frame;
The upper mold has a first recessed portion 31 for vacuum suction of the seat 1 mounted on the upper surface 11, and the lower mold is provided for vacuum suction of the seat 2 mounted on the lower surface 13. 2 grooves 41,
The upper mold and the lower mold press the sheets 1 and 2 mounted on the upper and lower surfaces to form a closed system while supplying air to the space created by the first and second recesses using the nozzles. 1) A molding apparatus, characterized in that the vacuum suction of (2) to make a molding having a hollow portion (v) therein. The method of claim 1,
The tip 16 of the frame has an inclined surface 12,
Among the pressurizing cylinders, the pressurizing cylinder installed to correspond to the front end 16 includes a pressurizing block 51 having an inclined surface 53 that mates with the inclined surface 12, and the pressurizing block 51 has the front end 16. Forming apparatus characterized in that the inclined surfaces (12) (53) cooperate with each other to press the sheet (1) (2) when pressing. 3. The method of claim 2,
The pressing block (51) is characterized in that it has a horizontal surface (54) extending horizontally from the end of the inclined surface (53). The method of claim 1,
The moving means,
An orbital installed on both sides (18) of the frame in the longitudinal direction of the frame and rotating in an infinite orbit; And
And a needle part installed in the track and inserted into the seat (1) (2),
A sheeting apparatus, characterized in that the sheet (1) (2) moves by moving the track in the state where the needle portion is inserted into the sheet (1) (2). 5. The method of claim 4,
The trajectory of the moving means is such that the seat (1) (2) and the frame is in close contact with the needle portion is inserted into the seat (1) (2),
The frame (17) for supplying hot air or air at room temperature to the seat (1) (2) mounted on the upper and lower surfaces, and a nozzle (17) for supplying a closed space (s2) formed by the frame, the pressurizing cylinder and the moving means. Molding apparatus characterized in that the installation. The method of claim 1,
The upper mold includes one of the trimming knife and the groove around the first concave portion 31, and the lower mold includes the other of the trimming knife and the groove around the second recess 41. , The trimming knife and the groove correspond to the edge of the molding,
Forming apparatus, characterized in that the edge of the molding is cut by inserting a trimming knife into the groove after the molding of the molding. delete The method of claim 1,
Heater,
An upper heater 20 installed on the upper surface 11; And
And a lower heater (25) disposed below the lower surface (13). (a) mounting the seats (1) and (2) on the upper and lower surfaces (11) and (13) of the frame having an open end (16) and having a 'c'shape;
(b) Pressing the seats 1 and 2 against the frame using at least a pressurizing cylinder installed so as to correspond to the rear end 19 and the front end 16 of the frame to securely fix the seats 1 and 2 to the frame. Making;
(c) heating the sheet (1) (2) using a heater; And
(d) moving the upper mold and the lower mold to pressurize the sheets (1) and (2) to form a closed system, and then vacuum forming the sheets (1) and (2) to form a molding having a hollow portion (v) formed therein. It includes;
The tip 16 of the frame has an inclined surface 12,
The pressurizing cylinder installed to correspond to the tip of the pressurizing cylinder includes a press block 51 having an inclined surface 53 that mates with the inclined surface 12, and the pressurizing block 51 presses the inclined surface when pressing the tip. (12) A molding method, characterized in that (53) cooperate with each other to fix the sheets (1) (2). 10. The method of claim 9,
The step (c)
A molding method comprising inflating the sheet by injecting hot air into the space (s2) formed by the sheet (1) (2) and the frame and the pressurizing cylinder. 10. The method of claim 9,
The step (d)
Forming method comprising the step of cooling the molding by injecting cooling air into the hollow (v). 10. The method of claim 9,
After the step (d)
And cutting the rim of the molding by operating a trimming knife mounted on any one of the upper mold and the lower mold. 10. The method of claim 9,
It is provided in the frame, and provided with a moving means for moving the seat (1) (2) provided on the upper surface 11 and the lower surface 13,
The moving means,
An orbital installed on both sides (18) of the frame in the longitudinal direction of the frame and rotating in an infinite orbit; And
And a needle part installed in the track and inserted into the seat (1) (2),
A molding method, characterized in that the seat (1) (2) is moved by the movement of the track in the state where the needle part is inserted into the seat (1) (2). 14. The method of claim 13,
The orbit is characterized in that the sheet (1) (2) is in close contact with the frame. delete 15. The method according to any one of claims 9 to 14,
The sheet (1) (2) is a molding method, characterized in that the foam sheet.

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