JPH0490941A - Manufacture of flexible bag body fiber formation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a flexible bag fiber molded product.

[Conventional technology]

The flexible bag fiber molded product is usually stored in the center of the steering wheel of a vehicle, and when the vehicle collides or suddenly stops, it senses the impact and instantly inflates and deploys to ensure the safety of the occupants. Things related to bags are known.

This airbag is designed to instantly send gas into the bag by exploding gunpowder, so it is required to be able to withstand the impact sufficiently.

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 may be lower than other methods, and the strength of the sewing parts There are problems such as the time and effort required to test the air permeability, and in addition, there is the problem that there is basically no sufficient confidence in the sewing itself.

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 the problems of the prior art, and its purpose is to provide a lightweight flexible bag that is homogeneous, has high reliability, is easy to manufacture, can be stored compactly, and is lightweight. An object of the present invention is to provide a method for manufacturing a body fiber molded article.

[Means to solve the problem]

In order to achieve the above object, the gist of the present invention is to obtain a tape by coating a fiber yarn or tow with an elastomer and then opening the filaments so that they remain substantially straight and parallel. A first invention provides a method for manufacturing a flexible bag fiber molded article, which is characterized in that the elastomer is manufactured by winding it around a mandrel having a certain size and shape, and in the first invention, the elastomer is a rubber composition. The second invention is a method for manufacturing a flexible bag fiber molded article, which is characterized by subjecting a tape attached around a mandrel to a vulcanization treatment.

In the present specification, the term "tape" refers to "a sheet of one or several yarns (multifilament threads) arranged in such a way that the monofilaments remain substantially straight and parallel; each monofilament is "Things that are interconnected 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 they are not particularly limited, and include all fibers conventionally used for bonding with rubber.

The fineness of the yarn of the present invention is not particularly limited, but is generally in the range of 30 to 30,000 D. Of course, these do not necessarily have to be supplied as a single thread; rather, it is easier to spread them horizontally if a plurality of threads are supplied at the same time. The thinner the monofilament fineness is, the wider it is (
, for example 0.8 to IOD, is generally preferred.

The elastomer used in the present invention preferably has flexibility and appropriate elasticity.

The elastomer may be a mixture of natural rubber or synthetic rubber such as acrylic, urethane, polybutadiene, styrene-butadiene, or ethylene-propylene, reinforcing agents, flame retardants, vulcanizing agents, etc. If more heat resistance than the above-mentioned elastomer is required, the heat-resistant elastomer may include one or more of synthetic rubbers such as chloroprene-based butyl rubber, halogenated butyl rubber, silicone-based and fluorine-based rubbers. It is preferable to use a composition in which necessary additives such as a reinforcing agent, an N-fuel agent, and a vulcanizing agent are mixed together.

In addition to the dip coating method, methods for coating fiber yarns or tow with an elastomer include dip coating in a dispersion state, and coating the elastomer by passing the yarn or tow through an atmosphere in which the elastomer is powder-injected or scattered. A method of attaching the same can also be used.

Methods for opening the elastomer-coated yarn or tow include electrical methods, mechanical methods, and methods using air flow, but any method may be used as long as the purpose can be achieved; for example, mechanical methods include , apply pressure to the yarn or tow from above and below with pressure rollers,
A method of spreading the yarn or tow in the lateral direction and opening it can be adopted. By providing this pressure roller with a temperature control function, it is possible to obtain optimal opening conditions by appropriately selecting a combination of opening pressure, yarn or tow feeding speed, and opening temperature.

In the present invention, methods for winding the tape around a mandrel having a predetermined size and shape include a traverse method, a rotating arm method, and other methods in which an arm or a mandrel performs a special rotational movement to wind the tape. Either format can be applied.

Divided by shape, there are methods for winding closed shapes such as cocoons, spheres, and cones; methods for winding shapes such as cylinders and discs; and methods for winding irregular shapes such as prisms and pyramids. It can also be applied by method.

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 uniformly by forming the bag with a laminated structure of at least two or more layers with different winding directions.

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.

In the vulcanization process of an elastomer made of a rubber composition, adjacent filaments that are crossed or parallel are fused together using an elastomer that has previously covered the filaments, thereby maintaining the shape after demolding and protecting the filaments. This is an important step in the present invention. The temperature condition is 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 20
Harsh conditions such as temperatures above 0°C and heating times of 20 minutes or more should be avoided.

[Function] Since the yarn or tow is coated with an elastomer in advance, sliding between the monofilaments is good and opening is performed smoothly.

Since the tape obtained as a result of this opening is wrapped around a mandrel to obtain a hang, there is no need for sewing, and since the filaments are bonded with an elastomer, the resulting bag is flexible and can be used freely. It is foldable and strong because it is reinforced with filaments.

As described above, according to the present invention, a strong 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 Figure 1, 1 is 66 nylon 1260D.

Five of these yarns were passed through the rubber solution impregnating device 2 in a direction parallel to the plane of the paper, keeping the distance between each other at 9.45 mm, and a rubber composition having the formulation shown in Table 1 was soaked in toluene. After impregnating with the melted rubber solution 3, the adhesion amount was controlled to 20 g/m2 using a doctor knife 4. Arrow A indicates the direction of yarn travel. Note that the above 9.45 m+n corresponds to the width when one yarn is opened to the size of one monofilament. (One yarn consists of 315 monofilaments) and
The yarn 1 is passed between opposing rollers 5 and 60, passed through roller 7, and sandwiched at the top and bottom by release papers 10a and 10b supplied via rollers 8 and 9, and then passed through the pressure roller 11.
．． At step 12, a pressure of 100 kg/cm" was applied from above and below, and the five yarns were opened by pushing them apart in the transverse direction. As a result, the yarns were opened by applying a pressure of 100 kg/cm" from above and below to spread them in the transverse direction.
It spread more than 0 times thinner.

In this way, a tape 13 (see Fig. 2) having a width W of about 50 mm is obtained, and while the release paper is wound up by rollers 15 and 16, the tape 13 is passed through rollers 17 and passed through the rotation axis of the disc-shaped mandrel 2o. The tape was wrapped at a winding angle of 14.5° and at a tape feed rate of 10 m/min on a decomposable metal disc-shaped mandrel 20 coated with a release agent in advance through a delivery eye 18 that reciprocated in a direction parallel to the tape 19. It was wrapped evenly with a sine until there were no gaps. In the above-mentioned FIG. 2, 14 is a monofilament.

Thereafter, the monofilaments were vulcanized under heating and pressure conditions of 180° C. and 10.5 kg/cm 2 to firmly adhere the monofilaments with rubber. Next, the disc-shaped mandrel 20 was disassembled and the bag formed on the mandrel was taken out. The state in which the bag body 21 is inflated and deployed is shown in FIG.

(Example 2) Fig. 4 shows another example, in which there is no impregnating device, and 40 g of the same rubber solution 3 as above was mixed with a mixing device (not shown) attached to the lower release paper 10b. m" coating, and on top of that, five yarns 1 were placed in a direction parallel to the plane of the paper, keeping the distance between each other at 9.45 m, and then a release paper 10a was layered on top of that. A bag body was obtained by the same process and under the same conditions as in Example 1.

Note that drying of the coating liquid can be accelerated by attaching a drying facility to an appropriate location on the rear surface of the pressure roller.

Table 1 (Comparative Example) As a comparative example, a plain woven fabric with a warp density and a weft density of 24 threads/dim each was produced using 840 denier yarn. Next, a rubber solution prepared by dissolving a rubber composition having the composition shown in Table 1 in toluene was applied to one side of this plain woven fabric. The amount of this coating was 65 g/m'' in terms of solid content.Then, it was vulcanized at 150°C for 14 minutes to obtain two woven fabrics coated with rubber solution on one side, and these two woven fabrics were sewn. A bag body having the same external shape as bag body 21 was produced.

(Performance Comparison Test) Next, a comparative test was conducted on the bag according to Example 1 and the bag according to 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
0 bags were made and each bag contained 2 kg/CII+2
The number of bags that did not burst was investigated by applying an internal pressure of

■Storability The height when the bags were folded into a 20 cm square 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 completely reach the expanded position was measured and expressed as an index with the comparative example being 100. The lower the index, the better the speed and developability.

The above test results are shown in Table 2 below.

Table 2 As is clear from Table 2, the bag according to this example weighs 2 kg.
/cm'' pressure test, none of the 1,000 pieces burst, but 9 pieces in the comparative example burst.
The rupture location was the sewing area.

Furthermore, the bag according to this example is significantly superior to the comparative example in terms of storability and expandability.

〔Effect of the invention〕

■Unlike bags formed from woven or knitted fabrics, the bag according to the present invention has a structure in which ultra-thin tape is wound around a mandrel, so it is easy to wrap once, is compact, and has high reliability. Since no sewing is required, the production process can be streamlined, and a strong flexible bag fiber molded product with an integral structure can be manufactured at low cost.

(2) In the present invention, since the filament is bonded with an elastomer, the resulting flexible bag fiber molded product is flexible and can be folded freely.

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

As described above, according to the present invention, a tough flexible bag fiber molded product reinforced with filaments can be obtained very 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 flexible bag fiber molded product according to the present invention
In particular, it has an exhaust port, a mounting port, etc., and is ideal for automotive airbags that require high strength. In addition, by changing the ratio of filament and elastomer using the technology of the present invention, it can be used for gases such as hot air balloons, atto balloons, balloons such as airships, shock-absorbing bags during collisions of high-speed moving objects, and bags for use in mines. It can be applied to gas bags for blocking blast waves caused by explosions, flexible containers for powders, fuel tanks and water storage tanks for liquids, and 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 a perspective view of the tape, Fig. 3 is a perspective view of the bag according to the present invention in an inflated and deployed state, and Fig. 4 is a diagram of the present invention. It is a side view of each process which shows another Example. 1... Yarn, 13... Tape, 20... Disc-shaped mandrel, 21... Bag body

Claims (1)

[Claims] 1) A tape is obtained by coating a fiber yarn or tow with an elastomer and then opening the filaments so that they remain substantially straight and parallel, and this tape is shaped into a predetermined size and shape. 2) The elastomer is a rubber composition, and the tape wound around the mandrel is subjected to vulcanization treatment. The method for producing a flexible bag fiber molded article according to claim 1, characterized in that: