JPH07108248B2 - Bag manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a bag body such as a water bed.

[Conventional technology]

Articles used by enclosing air or liquid in the bag, for example,
In water beds, air mats, air boats, etc., in order to maintain the shape of the bag body constant when liquid or air is enclosed, the upper and lower sheets of the bag body are connected and the distance between both sheets is kept constant. Often used hanging equipment to keep. Conventionally, the I-beam system, the X-beam system, and the waffle beam system are known as the hanging structure. In either method, in short, the hanger consists of a pair of mounting edges that are attached to the seat surface and a hanger body that connects the mounting edges of the pair. If it is a flexible sheet, it is attached by heat welding.

[Problems to be Solved by the Invention]

However, when an adhesive is used to attach the hanger, it is possible to obtain sufficient attachment strength by selecting the material of the adhesive, but the adhesion process is very troublesome. On the other hand, when attaching a suspender to a bag made of a heat-fusible sheet by using a thermocompression bonding method, it is difficult to set conditions such as an electrode crimping force, a bonding area, and a bonding range. Especially when high-frequency welding is used, the thickness of the peripheral sheet of the joint or the attachment edge of the hanger becomes thin, and the molten resin squeezes out at the periphery of the joint to form cracks, and the internal and external pressure applied to the bag body is generated there. However, there is a drawback in that the sheet or the hanger is damaged because it concentrates and acts at an acute angle in the direction of the seat and the hanger, and the force cannot be endured. In order to solve this drawback, the inventor has previously made the hanging cloth main body 11 as shown in FIG.
And a hanging cloth reinforcement piece 12 sewn to one end of the hanging cloth body 11.
And a hanging cloth reinforcing piece 13 sewn to the other end side opposite to the one end side, the hanging cloth body 11 is made of a material which is not heat-welded or hard to be heat-welded, and each hanging cloth reinforcement piece 12 is provided. A bag and a method of manufacturing the same have been proposed (see Japanese Patent Application Laid-Open No. 1-230303). As is apparent from the figure, this hanging tool is classified into the I-beam system, and the inside and outside of the bag body is welded by welding the upper and lower sheets 14 and 15 of the hanging cloth reinforcement pieces 12 and 13 to the bag body. It is possible to improve the durability by converting the acting direction of the tension to be applied to the hanger against the pressure into the direction of the seat surface. However, in the case of the above hanging structure, it is necessary to change the posture of the bag body and press the electrode at the point X in the figure for each of the hanging cloth reinforcing pieces 12 and 13 and weld it to each sheet. Moreover, the hanger is
It is attached inside the bag, and the upper and lower sheets
There is room for improvement in terms of workability by sequentially applying the hanging cloth reinforcing pieces 12, 13 to the inner surfaces of 14, 15 and performing the welding process.

An object of the present invention is to further improve the structure of the hanger used in the prior art, and to provide a method for manufacturing a bag body capable of welding the hanger to the upper sheet and the lower sheet of the bag body in a single welding step. is there.

[Means for Solving the Problems]

In order to achieve the above object, in the method for manufacturing a bag according to the present invention, a step of inserting a hanger, and a thermocompression bonding step,
A method for constructing a bag body in which the upper and lower sheets of the bag body are connected to each other at a fixed interval to hold the bag body in a fixed shape, wherein the upper and lower sheets of the bag body are airtight and watertight polyvinyl chloride. Is a thermoplastic synthetic resin sheet such as that, which forms the facing surface of the bag body, and the suspender connects between the upper and lower sheets of the bag body,
It consists of a pair of mounting edges and a main body of the hanger. The pair of mounting edges are to be welded to the facing surfaces of the upper and lower sheets of the bag, respectively, and are made of a heat-meltable material. It is made of a non-melting or heat-fusible material and is attached to a pair of mounting edges, and keeps a constant space between both mounting edges. When folded in two, it can be folded. Each cloth surface has a size necessary to cover the entire opposite surface of the mounting edge of the pair, and in the step of inserting the suspending tool, fold the suspending tool body between the pair of mounting edges,
This is a process in which the facing surfaces of the surface mounting edges are separated by a hanger body and is inserted between the upper and lower sheets of the bag body. In the thermocompression bonding process, the hanger is sandwiched between the upper and lower sheets. This is a step of thermocompression bonding and welding and joining the upper sheet and the upper mounting edge and the lower sheet and the lower mounting edge, respectively.

Further, the thermocompression bonding step is a step of welding and joining the sheet and the mounting edge in a multiple width parallel line shape with a constant width over the entire width of the mounting edge by using a multi-strand push blade electrode on one of the electrodes, The sheet and the mounting edge are welded and joined in one thermocompression bonding step.

[Action]

When the hanging body is folded and the mounting edges at both ends are overlapped, the facing surface of the mounting edge is covered by the hanging body. Therefore, when the suspending tool is inserted between the upper and lower sheets of the bag and the upper and lower sheets are welded by sandwiching them between the electrodes, the upper and lower sheets and the mounting edge in contact with them are made of a thermoplastic material. Although they are fusion-bonded, since a suspending tool body made of a heat infusible material or a heat-hardly melting material is interposed between both mounting edges, both mounting edges or between the mounting edge and the lifting tool body are connected. Does not weld. It should be noted that a multi-strand push blade electrode is used for the welding electrode in order to increase the bonding strength without causing deterioration of the material due to welding.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a partial cross section of the bag body in which the suspenders 3 are attached to the inner surfaces of the upper and lower sheets 1 and 2. The upper sheet 1 and the lower sheet 2 of the bag body are thermoplastic synthetic resin sheets such as polyvinyl chloride having air-tightness and water-tightness, and form the facing surfaces of the bag body. The suspending tool 3 is to maintain the space between the upper and lower sheets 1 and 2 at a constant value to keep the bag in a fixed shape. The suspending tool 4 and the pair of mounting edges 5a and 5b Has become.
The hanging body 4 is a tape of a fixed length that defines the distance between the upper and lower sheets 1 and 2, and the mounting edges 5a and 5b are fixed to the hanging body 4 by sewing or other means. The
Each is welded to the inner surfaces of the sheets 1 and 2. In the embodiment, the hanger body 4 is sewn at the center of the cross section of the mounting edges 5a, 5b, and as shown in FIG. 2, the cloth edge 4a of the hanger body 4 ahead of the sewn portion is the mounting edge 5a or The cloth surface 4b has a size large enough to cover one half surface of 5b, and the half of the rising height of the hanger body 4 that connects the two mounting edges 5a and 5b is the mounting edge.
It is large enough to cover the other half of 5a or 5b. Specifically, as shown in FIG.
When folded in half, the cloth surface of the hanger body 4
This means that it has a size capable of covering the entire surfaces of the upper and lower mounting edges 5a, 5b facing each other. For the hanging body 4, a material that does not heat-melt (heat-insoluble material) or a material that does not melt easily (heat-melting material), for example, woven fabric of natural fibers such as cotton and hemp, polyester, nylon, polyurethane, etc. Select and use woven fabric of synthetic fiber. In addition, it is necessary to use a material that does not easily fray and has high tensile strength for the purpose of use as a hanging tool. Of course, not only woven cloth,
It may be a synthetic resin sheet or a non-woven fabric.

The mounting edges 5a and 5b may be made of a material (heat-melting material) capable of being heat-welded at least on the surface to be joined to the sheet, and may be a synthetic resin sheet of the same material as the sheet or a cloth impregnated with the same synthetic resin, or a laminate. Use the body.

The procedure for welding the hanger to the bag is as follows. That is, in FIG. 2, the lower sheet 2 of the bag body is placed on the lower surface plate electrode 6 of the high-frequency welder machine, the upper sheet 1 is opened, and the suspending tool 3 is inserted between the both sheets 1 and 2. The hanging device 3 is obtained by folding the hanging device main body 4 into two as shown in the drawing,
Is inserted between the seats 1 and 2 with the attachment lines 5a and 5b being vertically overlapped with each other and sandwiched between the attachment edges 5a and 5b. A multi-row push blade electrode is used as the upper electrode 7, and the upper surface of the sheet 1 is pressed corresponding to the insertion position of the hanging tool 3 to apply a high frequency voltage between the electrodes 6 and 7. This makes it a thermoplastic material,
The mounting edges 5a and 5b of the lower sheets 1 and 2 and the hanger 3 are melted, and the upper sheet 1 and the upper mounting edge 5a and the lower sheet 2 and the lower mounting edge 5b which are adjacent to each other are the entire widths of the respective mounting edges 5a and 5b. Is welded in a multi-line form. However, the upper and lower mounting edges 5a, 5b
And the hanger body 4 between them are not welded to each other because the hanger body 4 is made of a heat infusible material or a heat infusible material. Therefore, the suspender 3 is integrally attached to the bag body by welding the sheets 1 and 2 and the attachment edges 5a and 5b as shown in FIG.

Regarding the electrode structure, it is important to set the shape of the push blade of the upper electrode. When the height of the push blades is H, the thickness of the push blades is T, the interval between the push blades is t (see FIG. 2), the following requirements must be met.

H is not less than about half the thickness of the object to be heated (thickness of the upper and lower sheets and the folded hanger), preferably the same height or less, and T is 0.5 It is desirable that the range is mm to 3 mm and T ≦ t.

Of course, even if T> t, welding is possible, but when welding a wide range over the entire mounting edges 5a, 5b, there is a risk that the welding position may shift, and the tensile strength of the welding location descend.

Regarding the power consumption, the method of the present invention will be described in comparison with the case where a flat electrode is used as the upper electrode. It is said that the bonding capacity of the high-frequency welder is 10 cm ² per 1 kW of output.

For example, when high-frequency welding is performed in a range of 20 mm (width) × 1000 mm (length), the upper electrode 7 is a multi-row push blade electrode (t = 2.8 mm × 5 (spacing), T = 1 mm × 6 ( ()), The welding area is 60 cm ² , and the electrode required for welding is 6 kW.

On the other hand, when a flat electrode is used as the upper electrode, the welding area is 200 cm ² , and the electric power required for welding is 20 kW. Therefore, according to the present invention, bonding can be performed with a power consumption of 1/3 as compared with the case where a flat electrode is used as the upper electrode.

Regarding the adhesive strength, when a flat electrode is used as the upper electrode, the residual thickness of the welded portion is 50-60% of the original thickness.
This causes deterioration of physical properties due to material deterioration.
In addition, a molten burr protrudes at the periphery of the joint to form a crack, which causes the lifting tool to come off and the sheet to be cut. Moreover, due to the application of high power, the mounting edge and the hanger body may adhere to each other due to the exudation of the molten resin.

According to the method of the present invention, under the above-described conditions, T and t are welded in parallel lines with a width of 6 mm with respect to a width of 20 mm in the welded region.
The remaining 14 mm retains its original thickness. Furthermore, since this 14 mm range is not heated, the deterioration of the physical properties due to material deterioration is small, and therefore the adhesive strength is greater than when using a flat electrode. Moreover, since multiple lines of linear bonding are performed with a small amount of electric power, there is no bonding between the mounting edge and the hanger body due to exudation of molten resin, and wide bonding with parallel lines is possible, which is equivalent to a strong adhesive. Strength is obtained.

In the above embodiment, the example of mounting by the I-beam method is shown.
The same applies to both the X-beam method and the waffle beam method.

〔The invention's effect〕

As described above, according to the present invention, the suspending tool can be attached to the sheet surface of the bag body by sandwiching the suspending tool main body between the upper and lower sheets of the bag body, and thus the water bed, the air mat, This has the effect of significantly improving the workability of bag processing that requires attachment of suspenders such as an air boat.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part of a bag body showing an embodiment of the present invention, FIG. 2 is a view showing a welding capacity of a hanger, and FIG. 3 is a view of a bag body to which a hanger is attached by a conventional method. FIG. 1 …… Upper sheet, 2 …… Lower sheet 3 …… Hangers, 5a, 5b …… Mounting edge 6 …… Lower electrode, 7 …… Upper electrode

Claims (2)

[Claims] 1. A step of inserting a hanger and a step of thermocompression bonding,
A method for manufacturing a bag body, in which the upper and lower sheets of the bag body are connected at a constant interval to hold the bag body in a fixed shape, wherein the upper and lower sheets of the bag body are airtight and watertight polyvinyl chloride. Is a thermoplastic synthetic resin sheet such as that, which forms the facing surface of the bag body, and the suspender connects between the upper and lower sheets of the bag body,
It consists of a pair of mounting edges and a main body of the hanger. The pair of mounting edges are to be welded to the facing surfaces of the upper and lower sheets of the bag, respectively, and are made of a heat-meltable material. It is made of a non-melting or heat-fusible material and is attached to a pair of mounting edges, and keeps a constant space between both mounting edges. When folded in two, it can be folded. Each cloth surface has a size necessary to cover the entire opposite surface of the mounting edge of the pair, and in the step of inserting the suspending tool, fold the suspending tool body between the pair of mounting edges,
This is a process of peeling between the facing surfaces of both mounting edges with the lifting tool body and inserting this between the upper and lower sheets of the bag body. In the thermocompression bonding process, the lifting tool is sandwiched between the upper and lower sheets. A method of manufacturing a bag body, which comprises a step of thermocompression bonding and welding and joining an upper sheet and an upper mounting edge and a lower sheet and a lower mounting edge, respectively. 2. The thermocompression bonding step uses a multi-row push blade electrode as one of the electrodes, and welds the sheet and the attachment edge in a constant width in a multiple parallel line shape over the entire width of the attachment edge. The method for manufacturing a bag according to claim 1, wherein the sheet and the mounting edge are welded and joined in one thermocompression bonding step.