JPH04154569A - Air blowing tube provided with self-close valve for expandable air bag and its manufacturing method - Google Patents

Abstract

PURPOSE:To permit the whole slit cutting process to be completely omitted and reduce the manufacturing costs of cushioning sheet by forming the non- fusible parts in the air blowing tubes to be passed through an expandable air bag and self-close valves therein in a simultaneous operation and using the same technique as in the non-fusible parts required for the tube formation. CONSTITUTION:A main area part 13 extending lengthwise along the middle of a tube film 11 consists of a central non-fusible part 14 and non-fusible side parts 15 extending sidewise to the film edges at predetermined intervals. The non-fusion treated tube film 11 is heat sealed to another tube film 12 with thus treated surface facing inward. The films 11 and 12 thus joined together are heat sealed at side edge 18 along the full length thereof with the non-fusible parts 15 left unsealed at intervals at the side edge 17 and these unsealed parts constitute self-close valves 19 and air blowing tubes 10. The air blowing tubes are spliced and inserted between two bag films 2 and 3 for forming the air bags 20 of an expandable cushioning sheet 1.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an air blowing tube with a self-closing valve for an inflatable air bag and to a method for manufacturing the same, and to an air blowing tube with a self-closing valve for an inflatable air bag. This invention relates to a cushioning material sheet formed by passing through a large number of inflatable airbags divided into sections. In particular, the present invention provides a self-closing valve as described above, which can be formed most simply without forming a cut such as a slit in the air blowing tube or connecting a separate valve. This invention relates to an air blowing tube and a cushioning material sheet in which the tube is inserted.

[Background of the invention]

A cushioning material sheet in which a number of individual inflatable airbags are arranged in series and air blowing tubes are provided that extend vertically through these airbags and form slit valves at predetermined intervals has already been developed by the applicant. (For example, Jikken Hei 1-12
No. 0288). When air is blown from one end of the air blowing tube, at least one slit valve provided in each air bag opens, allowing air to flow into each air bag, thereby inflating the air bag. When the airbag is inflated, the air blow tube is crushed flat and the slit valve closes to prevent air from escaping from the airbag.

To manufacture a conventional type of air blowing tube with a slit valve, you basically prepare two tube films, an upper and a lower tube, and cut slits into one of them at a predetermined interval in the length direction. A step of cutting into a + shape or an x shape is required. It is also necessary to form a non-welding part made of a thin film or coating of heat-resistant printing ink, silicone release agent, etc. on the major area of at least one inner surface of the tube film. This step is necessary in order to secure an air blowing passage when later inserting the air blowing tube into the air bag film and forming individual air bags by cross-sectional heat sealing.

The slit forming process itself is not very complicated, and there are no particular difficulties in implementing the process itself, but even if this process is omitted, it will still have a self-closing function with a simple structure similar to a slit valve. If this can be achieved, great advantages can be expected in actual production in terms of process simplification, cost reduction, etc.

In addition, after the airbag is inflated, the slit valve is pressed against the other side of the blow tube and closes in a self-sealing manner through surface-to-surface contact, so there are no particularly strict requirements and the specifications are relatively simple. However, if the air is blown with very strong air pressure, there is a risk that the ends of the slits, which are simply cut into the tube film, may tear or turn over.

Therefore, if a reliable self-closing valve with an equivalent or simpler structure could be obtained without using slits, it would improve the reliability of this type of cushioning material sheet in actual use and increase its commercial value. can be increased.

[Problem to be solved by the invention]

In view of this background, the present invention provides an air blowing tube equipped with a self-closing valve that is as reliable as or better than the conventional type without requiring processes such as cutting slits or installing separate valves. This was done with the basic goal of realizing this.

Specifically, it is an object of the present invention to simultaneously form a self-closing valve by directly utilizing the process of forming the non-weldable portion as described above, which is necessary when forming an air blowing tube.

A further object of the invention is to provide an inflatable cushioning sheet having an air blowing tube thus formed.

[Means to solve the problem]

For this reason, the present invention provides the following features:
Heat-sealable film (tube film)
a non-adhesive substance, such as a silicone-based heat-resistant release agent, a heat-resistant printing ink, or a Teflon coating, on the surface of the
Alternatively, a substance such as a solution of an inorganic powder such as talc, clay, etc., is applied to the central major area of the film;
From there, at predetermined intervals in the lengthwise direction, the parts extending laterally to the edge of the film are applied (in the shape of a stem and technique, so to speak), and the central non-weldable part and one interval are applied on the tube film. A lateral non-weldable portion and a weldable edge are formed.

A tube film that has been processed in this way can be heat-sealed to another tube film that has similar heat-sealability, or to the inner surface of a bag film that has heat-sealability that constitutes the airbag, which is the main part of the cushioning material sheet. The welding forms an air blowing passage within the inflatable airbag. That is, since the main area portion of the processed tube film is not welded to the other film, it acts as an air blowing passage that passes through multiple airbags when air is blown, and the side non-weldable portions act as air blowing passages that pass through multiple air bags. It serves as an inlet for the airbag, and after the airbag is inflated, it is compressed by the air pressure inside the airbag and functions as a self-closing valve.

According to the present invention, the formation of a self-closing valve is possible by using a process of applying a non-welding substance to a tube film, but if the application pattern of a non-welding substance is conventional, it is possible to form a self-closing valve by applying a non-welding substance to a tube film. It is possible to create an air blowing tube with a self-closing valve in an extremely efficient and economical way, since it is only necessary to slightly change the shape of the trunk and branches, and therefore the slit cutting process can be completely omitted. It can be manufactured.

Further, according to the present invention, since there is no need to cut the slits of the conventional type as described above, the process for that purpose can be omitted, and since no cuts (slits) are made in the air blowing tube, the It is also possible to eliminate the problem of the slit being unintentionally torn or turned over by the blowing air pressure. The heat welded part on the side edge of the air blowing tube is related to the strength of the tube itself and is made sufficiently strong so that it will not tear due to the blowing pressure. This eliminates the harmful effects of lacerations and enlargement.

〔Example〕

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

FIG. 1 is a plan view showing an example of a cushioning material sheet 1 in which individual airbags 20 are penetrated by an air blowing tube 10 having a self-closing valve 19 according to the present invention.

The air blowing tube 10 shown in FIG. 1 is constructed from a tube film 11 shown in partial plan view in FIG. Tube film 1 preferably consists of a nylon-polyethylene laminate film or other equivalent heat-sealable elongated length of material, and in the embodiment shown in Figures 1-4, another tube of the same type. Together with the tube film 12 (see FIG. 3), the blow tube 10 is constructed.

The tube film 11 shown in FIG.
4, and lateral non-weldable portions 15 are formed at regular intervals on the sides thereof, extending to the twilling portion of the film.

The end of the film is an open end 16 that serves as a blowing port when a blowing tube is constructed. Although not shown, the other end may also be an open end, or, if necessary, the non-weldable portion 14 may be terminated a little before this end to form a closed end.

The non-weldable areas 14.15 can be formed, for example, by applying a silicone-based heat-resistant release agent or a heat-resistant printing ink in a pattern conveniently represented by numerous dots in the drawings, or by applying a fine inorganic powder such as talc, clay, etc. It can be formed by applying in a similar pattern as a solution with an adhesive, or further by coating a heat resistant non-welding plastic such as Teflon or the like as a liquid or a thin film. Such non-weldable parts 14.1
It is sufficient to form 5 on only one of the two tube films 11, 12.

Side edges 17 and 1 due to the formation of non-weldable portions 14.15
8 is left as weldable. In particular, the lateral non-weldable portions 15 separate the individual airbags 2 to be formed later.
Although at least one location is located within 0, two or more locations may be located on the same side or on both sides as the case may be.

The non-welded tube film II is fitted with another tube film 12 with this processed surface as the inner surface, and subjected to a heat welding operation. The thermal welding operation is carried out by a method such as passing a matched film 11, 12 between a pair of heating rollers. The width (length) of the roller surface
- A smooth surface may be used, so that the cup presses the entire width of the film I1.12, or a roller may be used with two ridges in the form of a ring, so that the main pressing force is applied to the side edges 17.18. .

In any case, the laminated film 1 that has undergone heat welding treatment
1.12 is welded over its entire length on the side of the side edge 18 and is heat-sealed with interruptions at places on the side of the side edge 17 by non-weldable parts 15, these interruptions forming the self-closing valve 1.
9 to form an air blowing tube 10.

The air blowing tube 10 formed in this way is then attached to two bag films 2.3 (see FIG. 3) for constructing the air bag 20 of the inflatable cushioning material sheet 1.
is inserted into the Although FIG. 3 shows the airbag in an inflated state, initially both the blow tube 10 and the bag film 2.3 are in a flat state. The two bag films 2.3 are tube films 11.12
It is made of a heat-sealable film or sheet similar to the above, and its both side edges are heat-sealed by vertical seals 4 and 5 to form a flat cylindrical body. A similarly flat blowing tube 10 is inserted into this flat cylindrical body. The blowing tube 10 is positioned at the vertical center of the flat cylindrical body, and horizontal seals 6 are formed at predetermined intervals as shown in FIG. 1. There is only one horizontal seal 6 near both ends,
Preferably, the intermediate horizontal seals 6 are formed in a pair. This is to enable individual airbags 20 to be separated and used between a pair of horizontal seals 6 as required, but the cushioning material sheet is intended for limited applications where separation is not required during use. In this case, only one intermediate seal 6 is required.

By forming the transverse seals 6, the bag film 2.3 is divided into a number of individual airbags 20. Although FIG. 1 shows four airbags 20, the actual product is one.
It is preferable to connect 0 or more airbags 20 in series. The dimensions of the individual airbags 20 are not particularly limited, but may be, for example, about 8-20 am wide and about 1 am long.
It can be set to about 0 to 30 cm, and accordingly, the interval between the pair of horizontal seals 6 is preferably set to about 2 to 8 cI11. Having a large gap between the horizontal seals (connection area) will prevent two adjacent inflated airbags from colliding with each other if they are bent at or close to 90 degrees at the connection area (see Figure 7 below). This is necessary to prevent mismatches.

In addition, the length of each airbag and the length of the connection part are as follows:
It does not have to be uniform across a series of cushioning sheets. Accordingly, the number of self-closing valves 19 formed in the blow tube 10 per air bag can also be made variable.

By forming the horizontal seal 6, the upper and lower two bag films 2
．． 3 are welded together and the blow tube 10
It is also welded to the outer surface of the In the example of FIG. 3, the upper bag film 2 is welded to the outer surface of the upper tube film 12, and the lower bag film 3 is welded to the outer surface of the lower tube film 11. However, the inner surface of the blow tube IO is not welded due to the presence of the non-weldable portion 14 and is left open as an air blow passage through the multiple airbags.

The cushioning material sheet 1 of the present invention manufactured in this way is
It can be used as a cushioning material, a retaining material, a gap filling material, etc. According to one feature of the present invention, the cushioning material sheet 1 can be inserted, for example, in a flat state into a gap between articles placed in a container, or wrapped in a flat state around an article to be protected. put to use. The flat sheet of cushioning material 1 is then connected at the open end 16 of its air blowing tube 10 to a blowing device, such as a near compressor, and receives a blow of air pressure.

As can be seen from FIG. 3, when air pressure A is injected, the blow tube 10 expands, pushing open the self-closing valve 19 and allowing air a to flow into each air bag 20, thereby filling the air bag to the required limit or Inflate to allowable limit. The self-closing valve 19 is constituted by the unwelded side edges of the two upper and lower tube films 11 and 12, which are tightly closed by the welded side edges 17 on both sides. The central part of the self-closing valve opens particularly wide as shown schematically in the figure to allow air a to flow into the bag.

FIG. 4 is a schematic cross-sectional end view illustrating the action of the self-closing valve 19 after the airbag is inflated.

When sufficient air is blown into the airbag 20 and the blowing pressure to the blowing tube 10 is stopped, the air pressure r inside the airbag crushes the blowing tube IO into a thin and flat shape as shown. As a result, the non-welded side edges of the films 11, 12 constituting the self-closing valve 19 are also pressed together and close by themselves through surface-to-surface contact. As long as the air pressure r presses the self-closing valve 19 from its outer surface,
It is virtually impossible for air to penetrate between the films 11,12 of the self-closing valve and reopen it. In this way, each airbag 20 of the cushioning material sheet of the present invention is reliably maintained inflated by the self-closing valve 19.

5 is a schematic cross-sectional end view of an inflated airbag illustrating a second embodiment 10' of the air blowing tube of the present invention. The blow tube 10' of this embodiment is
Place only one tube 11 in one of the bag films,
In the figure, it is constructed by being bonded to the inner surface of the upper bag film 2 by welding or adhesive. The tube film 11 is
Although a pattern of non-weldable portions 14 and 15 as shown in FIG. 2 may be used, FIG. 6 shows a tube film 11 with a different pattern in partial plan view. That is, the tube film 11 in FIG.
A pair of lateral non-weld parts 15 and 15' are formed opposite to each other on both sides of a non-weld part 14 occupying the central main area 13. The pair of lateral non-weldable portions may be formed in a staggered manner (staggered) without facing each other. The central non-weld portion 14 and the side non-weld portions 15, 15' are formed using substantially the same method and materials as in the case of the tube film shown in FIG. 2 described above, except for the pattern. It is done. A tube film 11 having a pair of lateral non-weldable portions 15, 15' branching out on both sides from a central trunk.
is bonded to the inner surface of the bag film 2 on its weldable side @17.18. In this embodiment, the bag film 2 is connected to the other bag film 3 and the vertical seal 4.
Preferably, the tube film 11 is bonded to the bag film 2 before being welded at step 5.

The completed cushioning material sheet 1 is blown in the same manner as described in connection with the previous example, and exhibits a self-closing action in the same manner. FIG. 5 can be seen as a blow tube 10' in which a lateral non-weldable portion is formed on only one side, or a pair of lateral non-weldable portions are formed on different sides, but in either case. However, when air pressure A is blown as described above from the open end 16 of the blow tube 10', the lateral non-welding portion 15 (and 15') of the self-closing valve 19
opens to allow air a to flow into the airbag 20.

The state when the airbags 20 are inflated and the blowing pressure is stopped is shown in FIG. 7 as a schematic longitudinal cross-sectional view of the three connected airbags 20. Since the air blowing tube 10' is provided along the upper bag film 2, when the bag film 2 expands and curves, it curves along with it, and is crushed into a thin and flat shape by the air pressure r inside the bag. A self-closing valve 19 is also pressed against the bag film 2, prohibiting air pressure r from escaping. In FIG. 7, the blowing tube 10' is drawn a little apart from the bag film 2 for convenience of illustration, but in reality, the tubes are completely in close contact with each other and there is no gap between them. Self-close valve 19
is depicted as a gap in FIG. 7 for convenience, but in reality, the non-weldable portion 15 closes tightly to the inner surface of the bag film 2, leaving no gap.

Note that the connection portions between the individual airbags 20 (between the pair of horizontal seals 6.6) are relatively large apart,
This is to prevent the inflated bags from colliding with each other and hindering their complete inflation when the two airbags on the right side are bent and arranged.

〔Effect of the invention〕

As explained above, according to the present invention, the work of forming a non-weldable part necessary for forming the tube on the air blowing tube that penetrates the inflatable air bag can be directly utilized, and at the same time, a self-closing valve can be installed. Since it is possible to form the air blowing tube, it is possible to completely omit the process of cutting slits as in the conventional type of blowing tube, saving equipment, time, process costs, etc. This has the effect of reducing the manufacturing cost of the sheet.

Furthermore, according to the present invention, the Mono 1 Fukurosu valve is formed without creating any "scratches" such as cuts in the tube film, so when the cushioning material sheet is put into use, the "scratches" are removed by blowing with strong air pressure. There is no risk of expansion, and the reliability of the self-closing valve can be improved.

Furthermore, when the blow tube of the present invention is formed from one tube film and the inner surface of the bag film itself, the blow tube after inflation curves along the inner surface of the bag film, so to speak, exposing debris into the air bag. Especially in the case of airbags made of transparent film, this has the effect of improving the appearance, and since the section where the self-closing valve is located curves with a relatively large curvature, there is no chance of the self-closing valve opening due to bending. There is no risk of loosening, and this is also effective in increasing the reliability of the self-closing valve.

[Brief explanation of drawings]

FIG. 1 is a plan view of an example of a cushioning material sheet through which an air blowing tube equipped with a self-closing valve according to the present invention is passed, and FIG. FIG. 3 is an enlarged partial plan view showing details of the air bag; FIG. FIG. 2 is a schematic cross-sectional end view for explaining. FIG. 4 is a schematic cross-sectional end view illustrating the action of the self-closing valve after the airbag is inflated in FIG. A schematic cross-sectional end view illustrating the inflation action of the air bag, FIG. 6 is a partial plan view showing details of a tube film suitable for the construction of the air blowing tube of FIG. 5, and FIG. FIG. 2 is a schematic longitudinal cross-sectional end view illustrating the state of an airbag using a blowing tube after being inflated. Main code 1... Cushioning material sheet 2.3... Bag film 4.5... Vertical seal 6... Horizontal seal 10.10'... Air blowing tube 11... Tube film 12...・Another tube film 13...Main area portion 14...Central non-weldable portion 15.15'...Side non-weldable portion 16...Open end 17.18... Side edge 19 (to be welded)...Self-closing valve 20...Individual airbag

Claims (1)

[Claims] 1. A central non-weldable portion on the main area of the inner surface of the elongated tube film, and lateral non-weldable portions that extend to the edge of the film at predetermined intervals on the sides of the tube film. a plurality of successive inflatable individually compartmented sections, the lateral non-weldable sections being welded with other heat-sealable films at the other side edges to form a self-closing valve at said lateral non-weldable sections; An air blowing tube that is placed through the airbag. 2. For the central and side non-welding parts, apply a non-welding material such as silicone heat-resistant release agent, heat-resistant printing ink, Teflon liquid, or inorganic powder liquid to the surface of the tube film. The air blowing tube of claim 1 formed by. 3. The air blowing tube according to claim 2, wherein at least one lateral non-weldable portion is formed within one airbag. 4. The air blowing tube according to claim 3, wherein the lateral non-weldable portions are formed in a pair opposite to both side edges of the tube film. 5. A central non-weldable part is provided along the film length direction in the main area of a long and thin tube film with heat sealability, and a film is provided on the sides of the central non-weldable part continuous with the central non-weldable part. Side non-welding parts are provided extending to the side edges of the film at predetermined intervals in the length direction, and the surfaces of these non-welding parts are aligned with the inner surface of another tube film or bag film that has heat sealability. forming an air blowing tube by heating and pressurizing the central non-welding portion, the central non-welding portion being present as an air blowing passage through a number of individually defined and continuous inflatable air bags; An air blower with a self-closing valve for an inflatable cushioning sheet, characterized in that the non-weldable part is a self-closing valve present in each airbag thus formed. Method of manufacturing tubes. 6. For the central and side non-welding parts, apply a non-welding material such as a silicone heat-resistant release agent, heat-resistant printing ink, Teflon liquid, or inorganic powder liquid to the surface of the tube film. 6. A method according to claim 5, formed by: 7. The method according to claim 5, wherein at least one lateral non-weldable portion is formed within one airbag. 8. The method according to claim 5, wherein the lateral non-weldable portions are formed in a pair opposite to both side edges of the tube film. 9. The main area of the inner surface of the elongated tube film has a central non-weldable portion, and lateral non-weldable portions that extend to the edges of the film at predetermined intervals on the sides in the length direction; The other side edges are welded with other heat-sealable films to form a self-closing valve at the side non-weldable portions. An inflatable cushioning material sheet passed through an airbag.