JPH0419251A - Bag for absorbing impact and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a tough bag for absorbing an impact by coating a tape form substance, in which filaments of a fiber are arranged linearly to keep a parallel state, with a crosslinkable thermoplastic elastomer, and winding the tape form substance around a mandrel having a given size and shape. CONSTITUTION:Five yarns with 1500 De/1000F of polyparaphenylene.3,4 diphenylether . terephthalamide are arranged to form a toe shaped and opened by a mechanical method to produce a tape form opening yarn 1. The opening yarn 1 is moved through an elastoma solution impregnating device 2 from a direction A. After the yarn is impregnated with an EVA emulsion solution 3, an adhering amount is controlled by means of a doctor knife 4 to produce a very thin tape 5. The tape is conveyed between rollers 7 and 8 and through rollers 9 and 10 and uniformly wound around a disc-shaped mandrel 13 through a delivery eye 11 reciprocating in a direction extending in parallel to a rotary shaft 12 of the mandrel 13 until no space is left therebetween. Further, after crosslinking treatment, the mandrel 13 is disassembled to take out a bag for absorbing an impact.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is normally housed in the center of the steering wheel of a vehicle, and upon a vehicle collision, it senses the impact and instantly inflates and deploys to protect the driver, etc. The present invention relates to a shock absorbing bag (so-called airbag) for ensuring the safety of people, and a method for manufacturing the same.

[Prior Art] Since airbags are made by exploding gunpowder to instantaneously send gas into the bag, they are required to sufficiently withstand the impact caused by the explosion.

The conventionally provided airbags are:
After forming a polymer coating on one side of a flat woven fabric, the two coated woven fabrics are stacked so that the coated sides face each other, and the periphery is sewn to form a bag.

For example, in the prior art section of Japanese Patent Application Laid-open No. 51-4742 (invention related to a bag for an airbag device and a manufacturing method thereof), it is stated that ``a circular piece of cloth is cut out from two square pieces of cloth and the periphery is sewn together. "Manufacturing a flat airbag" is disclosed.

[Problem to be solved by the invention]

However, the method of manufacturing airbags by sewing involves many manual steps (which makes it difficult to automate and cannot be manufactured economically), the strength of the sewing parts is often lower than other parts, and the strength of the sewing parts In addition, there are problems such as the time and effort required to test the air permeability, and there is also the problem that the sewing itself cannot be sufficiently reliable.

Therefore, if an excessively strong and thick woven fabric is used to improve reliability, the airbag becomes bulky and cannot be stored compactly in the center of the steering wheel or the like.

The present invention has been made in view of these problems of the conventional technology, and its purpose is to provide a homogeneous and highly reliable (
To provide a lightweight shock absorbing bag that is easy to manufacture, can be stored compactly, and a method for manufacturing the same.

[Means for Solving the Problems] In order to achieve the above object, the gist of the present invention is to create a tape-like product in which fiber filaments L- are arranged in a substantially linear and parallel state, or a tape-like product in which the tape is arranged in a bag-like state. The first invention is a shock-absorbing bag wound up into a tape-like bag in which fiber filaments are arranged in a substantially straight and parallel state, and this tape-like bag is cut into a predetermined size and A second invention provides a method for manufacturing a shock absorbing bag, which is characterized in that the bag is manufactured by winding it around a mandrel having a shape, and the method comprises winding a fiber yarn or tow around a shaped mandrel so that the filaments remain substantially straight and parallel. A third method of manufacturing a shock absorbing bag is characterized in that the fibers are opened to obtain a tape-like material, and the tape-like material is wound around a mandrel having a predetermined size and shape. In this invention, a tape is obtained by coating a tape with an elastomer in which the fiber filaments are arranged in a substantially straight and parallel state, and the tape is wound around a mandrel having a predetermined size and shape. A fourth invention is a method for manufacturing a shock absorbing bag, characterized in that the bag is manufactured by attaching the bag to a shock absorber. A fifth invention provides a method for producing a shock-absorbing bag, which comprises wrapping a tape-like material around a mandrel having a predetermined size and shape, and then coating the surface of the tape-like material with an elastomer. A tape is obtained by opening a fiber yarn or tow so that the filaments are kept in a substantially straight and parallel state, and then coating the tape with an elastomer to obtain a tape, which has a predetermined size and shape. The sixth invention is a method for manufacturing a shock absorbing bag, which is characterized in that it is manufactured by winding it around a mandrel. A shock-absorbing device comprising: obtaining a tape-like product, wrapping the tape-like product around a mandrel having a predetermined size and shape, and then coating the surface of the tape-like product with an elastomer. A seventh invention provides a method for manufacturing a bag, and in the fourth, fifth, sixth, or seventh invention, the elastomer is a crosslinkable thermoplastic resin, and the elastomer wrapped around a mandrel is coated. The first invention provides a method for manufacturing a shock-absorbing bag, which comprises subjecting a tape obtained by cross-linking to a crosslinking treatment.

In the specification of this application, "tape J" refers to "one or several yarns (multifilament threads) arranged in a sheet shape so that the monofilaments are maintained in a substantially straight and parallel state." Okay, "tape" means "
"A product in which the monofilaments constituting the above-mentioned tape-like material are mutually bonded and integrated."

The fibers of the present invention typically include human silk, polyvinyl alcohol fibers, aliphatic and aromatic polyamide fibers,
Examples include polyester fibers, carbon fibers, glass fibers, etc., but the fibers are not particularly limited, and include all fibers that can be bonded to resin.

There is no particular restriction on the fineness of the yarn of the present invention, but a range of 30 to 30,000 De is generally suitable. Of course, these do not necessarily need to be supplied in the form of a single thread; rather, it is easier to spread laterally if a plurality of threads are supplied at the same time. The finer the monofilament, the easier it is to spread, and for example, a range of 0.8 to 10 De is generally preferred.

Methods for opening these yarns include electrical methods, mechanical methods, and methods using air flow, but any method may be used as long as the purpose can be achieved.
Any method such as that disclosed in Japanese Patent No. 3-69626 may be used.

Note that the tape-like material obtained by the opening must be extremely uniform (with little variation in thickness). In addition, the monofilaments must be completely separated from each other, and their spacing must be close enough that the average spacing is less than the average filament diameter.

The tape may be coated with an elastomer before or after the tape is wound around the mandrel.

In addition to the dip coating method, methods for coating the elastomer include dip coating in a dispersion state, and methods in which the elastomer is powder-injected or passed through a heated filament in a scattered atmosphere to melt and adhere. can.

The elastomer used in the present invention is preferably a crosslinkable thermoplastic resin, and for example, vinyl chloride resin (PVC), polyethylene (PE), polypropylene (PP), ethylene-acid picopolymer (EVA), etc. can be used. These polymers can be made into a liquid by dissolving them in plastisol, emulsion, organic solvent, or the like.

In addition, the V1 match between the filament and the elastomer may be selected appropriately depending on the purpose and required characteristics, but for example,
Filament: Elastomer = 90~40: 10~
A ratio (weight ratio) of 60 is used. In particular, in the present invention, since the filaments are spread apart, when impregnated with the above-mentioned elastomer solution, the monofilaments can penetrate well and the monofilaments can be bonded uniformly with a small amount of elastomer, thus relatively increasing the filament ratio. be able to. In particular, when the content ratio of filaments is 50% or more, it becomes possible to bring out unprecedentedly high strength properties. In order to have a high content ratio of filaments and to allow the elastomer solution to penetrate well between the monofilaments, the filaments must be opened sufficiently to incorporate the elastomer solution into the monofilaments, and then the excess elastomer must be removed using a sharp edge such as a doctor knife. If a method such as removing the elastomer is used, it is possible to increase the filament ratio and obtain a composite structure in which the filament and the elastomer are completely integrated.

The filling rate of the elastomer between the monofilaments is approximately 60% or more of the voids between the monofilaments, especially 70% or more of the voids between the monofilaments.
Preferably, it is 90% or more filled with elastomer. If this filling rate is low, the object of the present invention cannot be fully achieved.

In the present invention, methods for winding a tape or a tape-like material around a mandrel having a predetermined size and shape include a traverse method, a rotating arm method, and other methods in which the arm or mandrel has a special rotational movement. Any special type of winding can be applied.

Divided into shapes, there are two methods: a method of winding closed shapes such as a cocoon, a sphere, and a cone; a method of winding a shape of a cylinder or a disk; and a method of winding an irregular shape such as a prism or pyramid. This method can also be applied.

Although there are various winding patterns, a predetermined strength can be imparted by broadly classifying them into parallel winding, helical winding, longitudinal winding, or a combination thereof. In cases where pressure is generated inside the bag, such as in an airbag, the pressure can be applied evenly by forming a laminated structure of two or more layers with different winding directions.

The purpose of crosslinking of elastomers made of thermoplastic resin is to fuse adjacent filaments in a crossing or parallel state with an elastomer that has previously covered the filaments, thereby maintaining the demolded shape and protecting the filaments. This is an important step in the present invention.

The temperature conditions are preferably a temperature at which the elastomer covering the filament exhibits a predetermined adhesive force, that is, 120 to 190°C. Considering thermal decomposition of the elastomer, the heating temperature is 200"C or more and the heating time is 20 minutes or more. Harsh conditions should be avoided.

When molding into a removable shape, use a deformable hollow body, such as a metal mandrel (which can be disassembled if necessary) or a rubber mandrel, and mold it into a closed shape. If so, use a consumable mandrel made of gypsum, rock salt, easily fused metal, etc. In order to easily remove the mandrel after molding, it is desirable to apply a mold release agent to the mandrel in advance.

[Effect]

Since the bag is obtained by winding a tape-shaped spread thread or a tape of spread thread around a mandrel, there is no need for sewing, and since the filament is bonded with an elastomer, the resulting bag is flexible. It can be folded freely and is strong because it is reinforced with filaments.

As described above, according to the present invention, a strong impact-absorbing bag having an integral structure can be obtained easily and inexpensively.

〔Example〕

Examples 1 and 2 of the present invention will be described below.

(Example 1) In Fig. 1, ■ indicates 1500De/1 of polyparaphenylene/3.4 diphenyl ether/terephthalamide.
This is a tape-shaped spread yarn obtained by mechanically opening five 1000 F yarns arranged in a tow shape. After impregnating the EVA emulsion solution 3 with the formulation shown in Table 1 on page 16, the adhesion amount was controlled to 20 g/m'' with a doctor knife 4. Arrow A
indicates the traveling direction of the tape-shaped spread yarn 1.

Coated with the elastomer solution in this way,
An extremely thin tape 5 having a thickness of 40 μm and a width of 8 mm was obtained.

An enlarged cross-section of this tape 5 is shown in FIG. In FIG. 2, 6 is a monofilament.

Then, the tape 5 is passed between opposing rollers 7.8, passed through rollers 9.10, and then passed through the disc-shaped mandrel 13.
The delivery eye 1 reciprocates in a direction parallel to the rotation axis 12 of the
1 onto a decomposable metal disk-shaped mandrel 13 coated with a release agent in advance, the tape is wound uniformly at a winding angle of 14.5° and a tape feed speed of 0° and 45 m/see until there are no gaps. Wearing. The above-mentioned FIG. 2 is an enlarged view of the cross section of the chi 15 and the edge of the disc-shaped mandrel 13.

Thereafter, the monofilaments were crosslinked at 180° C. for 60 minutes to firmly adhere the monofilaments using an elastomer. and,
The disc-shaped mandrel 13 was disassembled and the shock absorbing bag formed on the mandrel was taken out. A state in which the shock absorbing bag 14 is inflated and deployed is shown in FIG.

Table 1 (Example 2) As Example 2, the formulation of the elastomer melt is shown in Table 2 on the next page.
A tape of the spread yarn was wound around the disc-shaped mandrel 13 in the same manner as in Example 1, except that the procedure was as follows.

Thereafter, the monofilaments were crosslinked at 70° C. for 60 minutes to firmly bond the monofilaments together with an elastomer. and,
The disc-shaped mandrel 13 was disassembled and the shock absorbing bag formed on the mandrel was taken out. The state in which this shock absorbing bag is inflated and deployed is the same as that shown in FIG.

Table 2 (Comparative Example) As a comparative example, a plain woven fabric having a warp density and a weft density of 24 threads/hand' was produced using 840 denier yarn. Next, an elastomer solution having the composition shown in Table 1 on page 16 was applied to one side of this plain woven fabric. The coating amount was 65 g/m2 in terms of solid content. And 150°C
Two woven fabrics coated with an elastomer on one side were obtained by crosslinking for 14 minutes, and a bag having the same shape as in Example 1 was made from the two woven fabrics by sewing. The weight of this bag was 360g.

(Performance Comparison Test) Next, a comparative test was conducted on the shock absorbing bag according to Example 1 and the bag according to the comparative example in terms of pressure resistance, storability, and expandability according to the following method.

■Pressure resistance 100 for each of Examples and Comparative Examples
No bags were made, and an internal pressure of 2 kg/cm2 was applied to each bag, and the number of bags that did not burst was counted.

■Storability The height when the bags were folded to a 20c+n angle and stacked was measured and expressed as an index with the height of the comparative example as 100. The lower this index is, the more flexible and excellent the storage property is.

■ Deployability When an internal pressure of 2 kg/cm" was applied to the bag, the time required for the tip of the bag to reach the fully expanded position was measured and expressed as an index with the comparative example set as 100. This index The lower the value, the better the speed and developability.

The above test results are shown in Table 3 below.

Table 3 As is clear from Table 3, the bang according to this example is 2k
g/cm'' pressure test, none of the 1,000 bags burst, but nine of the bags in the comparative example burst, and the rupture location was at the seam. is also significantly superior to the comparative example in terms of storage and expandability.

〔Effect of the invention〕

■Unlike bags made from woven or knitted fabrics, the shock-absorbing bag of the present invention has a structure in which ultra-thin tape or tape-like material is wrapped around a mandrel, so it is easy to wrap, compact, and reliable. Since it has high durability and does not require sewing, the production process can be streamlined, and a strong impact-absorbing bag with an integrated structure can be manufactured at a low cost.

(2) In the present invention, since the filament is bonded to an elastomer, the resulting shock absorbing bag is flexible and can be folded freely.

(2) In the present invention, the filaments are fused to each other by the elastomer in a crosslinking process, and remain in that state to maintain the strength of the molded product.

As described above, according to the present invention, a strong impact-absorbing bag reinforced with filaments can be obtained extremely easily.

Furthermore, by changing the shape of the mandrel, bags of complex shapes can be obtained as desired.

■Since the present invention allows a strong bag of any shape to be integrally molded, the shock absorbing bag according to the present invention has an exhaust port, a mounting port, etc., and is particularly useful for automobiles that require high strength. Ideal for airbags. In addition, by changing the ratio of filament and elastomer using the technology of the present invention, hot air balloons, atto balloons,
Balloons such as airships, shock-absorbing bags for collisions with high-speed moving objects, gas bags to block blasts caused by mine explosions, flexible containers for powder, fuel tanks, water storage tanks, etc. for liquids, etc. It can also be applied to heat-resistant insulation materials for civil engineering construction work.

[Brief explanation of drawings]

Fig. 1 is a side view of each step showing an embodiment of the present invention, Fig. 2 is an enlarged view of the elastomer-coated tape cross section and the edge of the mandrel, and Fig. 3 is a perspective view showing the shock absorbing bag in an inflated and deployed state. It is a diagram. 1. Tape-shaped spread yarn, 5. Tape, 6. Monofilament, 13. Disc-shaped mandrel, ] 4. Shock-absorbing bag

Claims (1)

[Claims] 1) A tape-like item in which fiber filaments are arranged in a substantially straight and parallel state, or a shock-absorbing bag in which the tape is wound into a bag shape. 2) A shock-absorbing bag in which the fiber filaments are arranged in substantially straight lines. A shock-absorbing bag characterized in that it is manufactured by obtaining a tape-like product arranged so as to maintain a parallel state and wrapping the tape-like product around a mandrel having a predetermined size and shape. 3) A tape-like product is obtained by opening fiber yarns or tows so that the filaments remain substantially straight and parallel, and the tape-like material is then passed through a mandrel having a predetermined size and shape. 4) A method for producing a shock absorbing bag, characterized in that it is produced by wrapping it around a tape.4) A tape-like material in which the fiber filaments are arranged in a substantially straight and parallel state is coated with an elastomer to produce a tape. A method for manufacturing a shock absorbing bag, characterized in that the tape is wound around a mandrel having a predetermined size and shape. 5) The fiber filaments are maintained in a substantially straight and parallel state. The method is characterized in that a tape-shaped article arranged in the following manner is obtained, the tape-shaped article is wound around a mandrel having a predetermined size and shape, and then the surface of this tape-shaped article is coated with an elastomer. Method for manufacturing a shock absorbing bag 6) A tape is obtained by opening a fiber yarn or tow so that the filaments are maintained in a substantially straight and parallel state, and coating the tape with an elastomer to obtain a tape. 7) A method for manufacturing a shock absorbing bag, characterized in that it is manufactured by winding the fiber yarn or tow around a mandrel having a predetermined size and shape. The method is characterized in that the fibers are opened to obtain a tape-like material, and after this tape-like material is wrapped around a mandrel having a predetermined size and shape, the surface of this tape-like material is coated with an elastomer. 8) The elastomer is a crosslinkable thermoplastic resin,
The method for producing a shock absorbing bag according to claim 4, wherein the elastomer-coated tape wound around a mandrel is subjected to a crosslinking treatment.