KR101802477B1 - Airbag for the outer installation of the vehicles by using aramid fabrics - Google Patents

Abstract

The present invention relates to a fabric for an airbag and an airbag for a vehicle including the same, and more particularly to an aramid fabric including aramid fibers and a cover factor of 1,000 to 2,000, and an airbag for a vehicle including the same.
The airbag fabric of the present invention provides excellent retention, shape stability, and air-blocking effect when applied as an external airbag by securing excellent mechanical properties by using aramid fibers in an optimized range of physical properties, At the same time, the impact on the vehicle and the passenger can be minimized.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an air bag for an automobile including an aramid fabric,

The present invention relates to an external air bag for an automobile including an aramid fabric, and more particularly to an external air bag for automobiles including an aramid fabric excellent in mechanical properties such as toughness and energy absorbing performance along with excellent storage stability, .

Generally, an air bag detects a collision impact applied to a vehicle at the time of a frontal collision at a speed of about 40 km / h or more at a speed of about 40 km / h by the impact sensor, And inflates the inflator to supply air to the inflator, thereby protecting the driver and the passenger. The structure of a typical air bag system is the same as that shown in Fig.

1, a general airbag system includes an inflator 121 that generates gas by ignition of a priming tube 122, and an airbag 124 that inflates and deploys toward the driver of the driver's seat by the generated gas An airbag module 100 mounted on the steering wheel 101, an impact sensor 130 for generating an impact signal in the event of an impact, and an electronic control module (not shown) for igniting the primer 122 of the inflator 121 And an electronic control module 110. When the vehicle collides head-on, the airbag system configured as described above senses an impact in the impact sensor 130 and transmits a signal to the electronic control module 110. At this time, the electronic control module 110 recognizing this ignites the primer 122 to burn the gas generating agent in the inflator 121. The gas generating agent thus combusted expands the air bag 124 through rapid gas generation. The inflated and deployed airbag 124 partially absorbs the impact load due to the collision while contacting the front surface of the driver and collides with the inflated airbag 124 as the driver's head and chest move forward due to inertia The gas of the airbag 124 is rapidly discharged to the exhaust hole formed in the airbag 124, so that the front surface of the driver is buffered. Therefore, by effectively buffering the impact force transmitted to the driver in the frontal collision, it is possible to reduce the secondary injury.

As described above, the airbag used in the automobile is manufactured in a certain shape, and then folded to be mounted in a folded state, mounted on a handle of a car, a side window of a car, a side structure or the like, Allowing the airbag to expand and deploy.

Therefore, in order to effectively maintain the folding property and the package property of the airbag when the vehicle is mounted, to prevent damage and rupture of the airbag itself, to exhibit excellent airbag cushion deployment performance and to minimize the impact on passengers, Along with flexibility to reduce folding and impact on passengers is very important. However, there has been no proposal of a fabric for an air bag which can maintain sufficient air-blocking effect and flexibility at the same time for the safety of passengers, can withstand the impact of the air bag, and can be effectively installed in the vehicle.

Particularly, in the past, the airbag effectively buffered the impact force transmitted to the driver or other passengers. However, recently, the shock applied to the pedestrian or the impact applied to the vehicle itself is mounted on the outside of the vehicle Airbags are increasing. As described above, in the case of a bumper-type airbag, which plays a role of buffering the impact force against an impact applied to the vehicle body, particularly to the outside bumper of the vehicle, the airbag is generally mounted inside the vehicle, The amount of impact applied to the airbag itself is very high because it is necessary to absorb a high impact force against the airbag. In such a case, the airbag can not withstand such a high impact force, the impact force can not be buffered, and the airbag fabric is ruptured. Therefore, there is a limit in that the function can not be performed normally. to be.

Accordingly, even when applied to a bumper-type airbag, the airbag fabric having excellent mechanical properties, even under harsh conditions of high temperature and high humidity, and excellent storage stability that can be compactly folded together with excellent shape stability and air- Research on development is needed.

INDUSTRIAL APPLICABILITY The present invention can provide an airbag cushion which exhibits improved flexibility and mechanical properties as a raw material for an airbag and exhibits improved folding and developing performance while minimizing promotion and shock to the vehicle even when mounted outside the vehicle We want to provide the aramid fabric.

The present invention also provides a vehicle airbag comprising the aramid fabric.

The present invention relates to a vehicle comprising an aramid fiber and having an aramid fabric having a cover factor of 1200 to 1855 as shown in the following calculation formula 1 and a fiber strength of 0.4 kgf to 1.4 kgf according to the American Society for Testing and Materials Association ASTM D 4032 method Thereby providing an external air bag.

[Equation 1]

The present invention also seeks to provide a bumper type vehicle exterior air bag.

Hereinafter, the aramid fabric according to a specific embodiment of the present invention and the vehicle exterior air bag including the aramid fabric will be described in detail. It is to be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

In addition, throughout this specification, "comprising" or "containing ", unless specifically stated, refers to including any and all components (or components) Can not be interpreted as excluding.

INDUSTRIAL APPLICABILITY By applying the aramid yarn to fabricate the airbag fabric, excellent performance can be secured in a bumper type airbag mounted on the outside of the vehicle and capable of withstanding high impact force. Further, the present invention can remarkably lower the lubrication degree of the fabric for the airbag, thereby ensuring the excellent folding performance of the airbag cushion.

In the case of an airbag cushion, which is generally mounted inside a vehicle to protect the safety of an occupant, it has been manufactured mainly by applying nylon yarn to the present. Even when the nylon yarn is used to produce the cover factor at a level as high as 2,058, the tensile strength of the fabric is only 128 kgf / 10 mm, and the airbag cushion using such a fabric has the impact force There is a limit to bear. On the other hand, when the fineness or density of the yarn is increased by applying nylon-based yarn or the like in order to improve the strength of the fabric, the problem of woven fabric may occur, and the laminating degree of the fabric is too high, There arises a problem that the cushion can not be housed in the minimized range of the cushion.

As a result of experiments conducted by the present inventors, it has been found that when the cover factor of the fabric is made to be within a predetermined range by using aramid fibers, the degree of lapping of the fabric can be adjusted to an optimal range and the impact absorption performance for the vehicle and promotion can be maximized It has been found that excellent mechanical properties and air blocking effect can be obtained.

According to one embodiment of the invention, an aramid fabric is provided which can be effectively used for an outboard airbag. Such an aramid fabric may include aramid fibers, and cover factor (CF) as shown in the following equation 1 may be 1200 to 1855.

[Equation 1]

When the covering factor of the fabric is less than 1200, the tensile strength and the seam strength of the fabric are lowered due to a weak gathering force of the fabric, so that the airbag cushion can not exhibit sufficient shock absorbing performance, May occur. In addition, when the cover factor of the fabric exceeds 1855, the retention and foldability of the airbag cushion may be significantly deteriorated when the airbag is mounted.

The fabric for the airbag of the present invention is particularly suitable for use as an airbag cushion mounted on the exterior of a vehicle by optimizing the cover factor using aramid fibers as described above and by means of an inflator of increased capacity, Sufficient strength and heat resistance to withstand high pressure and high temperature inflator gas can be ensured.

At this time, the warp density and weft density of the aramid fabric, that is, the weaving density in the warp direction and the weft direction are 20 to 55 th / inch, preferably 21 to 54 th / inch, more preferably 22 to 53 th / inch. < / RTI > The warp density and the weft density of the aramid fabric may be more than 20 th / inch respectively in terms of securing excellent mechanical properties of the airbag fabric, and the warp density and weft density of the aramid fabric may be 55 th / inch or less.

Also, the total fineness of the aramid fibers used in the warp fineness and weft fineness, that is, the warp direction and the weft direction, used in the aramid fabric is 200 to 1,000 denier, preferably 250 to 950 denier, 900 denier. The warp fineness and weft fineness of the aramid fabric may be selected in the range as described above in terms of optimizing the cover factor of the fabric to ensure excellent mechanical properties and excellent lubrication properties. The denier is a unit representing the thickness of a yarn or a fiber and is 1 denier when the length is 9,000 m is 1 g.

The aramid fiber is used for the airbag fabric of the present invention to ensure excellent mechanical properties and heat resistance. The aramid fiber is characterized by a molecular structure in which a phenyl ring is connected to all the main chains except the amide group. The aramid has a meta-type (m-) and a para-form (p-) containing the repeating unit of the formula (1) according to the linkage state of the phenyl ring. In order to exhibit excellent physical properties in the airbag fabric of the present invention, poly (phenylene terephthalate)) can be used. Particularly, in the case of the para- (p-) aramid fiber, since the phenyl rings are laminated in the form of plates, the degree of crystallinity is very high, the heat resistance is excellent, and the mechanical properties such as high strength and high modulus of elasticity, As a material for producing an airbag cushion of the present invention.

The tensile strength of the aramid fiber may be greater than or equal to 15 g / d, or greater than or equal to 15 g / d, preferably greater than or equal to 18 g / d, and more preferably greater than or equal to 20 g / d. Further, the elongation at break of the aramid fiber may be 3% or more, or 3% to 35%, preferably 4% or more, more preferably 5% or more.

The aramid fabric of the present invention may have a lubrication of 0.4 kgf to 1.4 kgf or 0.79 kgf to 1.32 kgf according to the American Society for Testing and Materials ASTM D 4032 method. When the lapping degree of the fabric is more than 1.4 kgf, the folding property of the fabric is too low, so that the foldability of the airbag cushion may be considerably lowered. However, when the liner degree of the fabric is too low, sufficient protective support function may not be provided in expanding the air bag, and shape retention performance may be lowered even when the vehicle is mounted, so that the retention of the fabric may be reduced. Or more.

The tensile strength of the aramid fabric is preferably 150 kgf / 10 mm or more, or 150 to 500 kgf / 10 mm, more preferably 160 kgf / 10 mm or more, or 160 to 480 kgf / 10 mm, as measured by the American Society for Testing Materials ASTM D 5034 method. 10 mm, more preferably 170 kgf / 10 mm or more, or 170 to 400 kgf / 10 mm. If the tensile strength of the fabric is less than 150 kgf / 10 mm, it may not be able to exhibit sufficient shock absorption performance because it is mounted outside the vehicle. However, the tensile strength of the fabric may be 500 kgf / 10 mm or more in terms of improving the foldability of the airbag cushion by optimizing the liner degree and thickness of the fabric.

In addition, the aramid fabric of the present invention may have a fineness of 0.10 mm to 0.45 mm, preferably 0.12 mm to 0.43 mm, more preferably 0.15 mm to 0.40 mm, measured by the International Organization for Standardization ISO 2286-3 method have. If the thickness of the fabric is greater than 0.45 mm, the folding performance of the airbag cushion may be significantly deteriorated. If the thickness of the fabric is less than 0.12 mm, the shape retention performance of the airbag cushion after folding .

Meanwhile, the airbag fabric of the present invention may include a sewing part for joining the fabric in the process of manufacturing the airbag cushion. Since such a sewing portion is a portion where air is mainly discharged when the airbag is deployed, properties such as the seam strength and elongation of the sewing portion can be optimized. Particularly, it is desirable that the bonding performance of the entire portion of the airbag cushion is effectively maintained so that excellent expansion performance and expansion performance can be exhibited when the airbag is deployed due to rapid gas generation or the like.

In this respect, the fabric for the airbag of the present invention can optimize the material, fineness, sewing method, etc. of the sewing thread to improve the strength and elongation of the sewing thread of the sewing part and ensure excellent pressure-holding performance.

The sewing portion of the fabric for airbags is joined using a sewing yarn comprising at least one selected from the group consisting of a nylon yarn, a polyester yarn, a polyolefin yarn, and an aramid yarn, 66, nylon 46, Kevlar (aramid yarn), and the like, and most preferably, nylon 66 can be used.

The thickness of the sewing thread, that is, the total fineness may be in the range of 210 to 1260 denier, preferably 840 to 1260 denier. In terms of strength, the thickness of the sewing thread is preferably 210 denier or more, Is preferably 1260 denier or less.

The above-mentioned sewed yarn can be used at a tensile strength of 58 N or more, preferably 58 N to 110 N, measured by the method of American Society for Testing and Materials ASTM D 204-97, and preferably in the range of 89 N to 1,260 denier 110 N, 840 denier, and 58 N to 80 N, respectively. When the tensile strength of the sewing thread is less than the above range, the strength of the sewing part is too weak, so that the sewing part may be torn at the time of manufacturing or expanding the airbag. When the tensile strength is too large, the strength of the sewing part is too strong, The development time point or shape of the object may be abnormally developed.

In the airbag cushion of the present invention, the sewing part can be selected and used effectively according to the use of each part, and at least one sewing method from among a single lock, a double lock, a single chain, and a double chain can be applied.

The sewing part can be applied by adjusting the number of stitches to an optimum range according to the use of each part or the sewing method, preferably 20 to 80 ea / 100 mm, more preferably 25 to 75 ea / 100 mm, Can be sewn and bonded by adjusting the number of stitches to be 30 to 70 ea / 10 mm. If the number of stitches is less than 20 ea / 100 mm, the strength of the sewing portion is too weak, and the sewing portion may be torn at the time of manufacture or expansion. If the number of stitches exceeds 80 ea / 100 mm, The time or shape of the deployment of the airbag may be unfavorably developed upon damage or deployment of the airbag.

In the fabric for an airbag according to the present invention, the sewing portion has a seam strength of 100 kgf / 20 mm or more, or 100 to 400 kgf / 20 mm, preferably 130 kgf / 20 mm or more, or 130 to 150 kgf / 20 mm, as measured by the method of ASTM D 1683, Most preferably 150 kgf / 20 mm or more, or 150 to 350 kgf / 20 mm. The seam strength of the fabric may be 100 kgf / 20 mm or more in terms of ensuring sufficient mechanical properties to withstand the high temperature and high pressure inflator gas when the airbag inflates. When the fabric is damaged or the airbag is deployed, It is desirable to maintain the level at a high level.

In addition, the aramid fabric may further include a rubber component coating layer, which is preferably coated or laminated on the surface. The rubber component may be at least one selected from the group consisting of powder silicone, liquid silicone, polyurethane, chloroprene, neoprene rubber, and emulsion silicone resin. Is not limited to the above-mentioned materials. However, liquid silicone coating is preferable in terms of environment friendliness and mechanical properties.

The coating amount of the rubber component coating layer per unit area may be 20 to 200 g / m ² , preferably 20 to 100 g / m ² . In particular, in the case of a fabric for a side curtain airbag of OPW (One Piece Woven) type, the coating amount is preferably 30 g / m ² to 95 g / m ² , and in the case of plain weave for airbag, m ² to 50 g / m ² is preferable.

The aramid fabric of the present invention has a static air permeability of not more than 10.0 cfm or 0.3 to 10.0 cfm, preferably not more than 8.0 cfm, when ΔP is 125 pa, or not less than 8.0 cfm, according to ASTM D 737, 0.3 to 8.0 cfm, more preferably 5.0 cfm or less, or 0.3 to 5.0 cfm, and when? P is 500 pa, 14 cfm or less, or 4 to 14 cfm, preferably 12 cfm or less, or 4 to 12 cfm . Also, the dynamic air permeability according to the American Society for Testing and Materials Standards ASTM D 6476 method is less than or equal to 1,700 mm / s, preferably less than or equal to 1,600 mm / s, or from 200 to 1,600 mm / To 1,400 mm / s. In this case, the static air permeability refers to the amount of air passing through the fabric when a certain pressure is applied to the fabric for the airbag, and the lower the density of the fabric, the smaller the Denier per filament and the higher the density of the fabric. Also, the dynamic air permeability refers to the degree of air permeation to the fabric when an average instantaneous differential pressure of 30 to 70 kPa is applied. As the static fineness of the yarn is small and the density of the fabric is high, Lt; / RTI >

In particular, the air permeability of the aramid fabric can be significantly lowered by including a rubber component coating layer on the fabric, and air permeability close to 0 cfm can be ensured. However, when such a rubber component coating is performed, the coating fabric for an airbag of the present invention has a static air permeability according to the American Society for Testing and Materials Association standard ASTM D 737 of less than or equal to 0.1 cfm when? P is 125 pa , Preferably 0.05 cfm or less, or 0 to 0.05 cfm, and may be 0.3 cfm or less, or 0 to 0.3 cfm, preferably 0.1 cfm or 0 to 0.1 cfm when? P is 500 pa.

Here, when the aramid fabric of the present invention exceeds the upper limit value of the static air permeability range or the upper limit value of the dynamic air permeability range with respect to the uncoated fabric and the coated fabric, May be undesirable.

On the other hand, according to another embodiment of the invention, a method for producing an aramid fabric as described above is provided. The method for fabricating the fabric includes the steps of weaving the airbag for the airbag such that the cover factor is 1,000 to 2,000 as shown in the following formula 1 using aramid fibers, refining the raw paper for the airbag weaving, And a step of opening and fixing the opening.

[Equation 1]

In the present invention, the aramid fiber is manufactured through the conventional weaving method, the refining and the heat fixing process to the airbag cushion fabric so that the cover factor can be optimized, and then, if necessary, It is possible. The airbag cushion fabric thus coated is cut and sewed as described below to produce a certain type of airbag cushion. At this time, the airbag cushion is not limited to a specific shape and can be manufactured in a general shape, for example, both a plain weave type and an OPW (One Piece Woven) type weave shape are preferable.

In particular, the fabric for an airbag of the present invention can be manufactured through the steps of beaming, weaving, refining, and heat fixing using aramid fibers as weft yarns and warp yarns. The fabric may be manufactured using a conventional weaving machine, and is not limited to the use of any specific loom. However, plain weave fabrics may be manufactured using a Rapier Loom, an Air Jet Loom, or a Water Jet Loom, and the OPW type fabric may be manufactured using Jacquard looms Loom. ≪ / RTI >

On the other hand, according to another embodiment of the invention, there is provided an outside air bag for vehicles including the above-mentioned aramid fabric. Also provided is an airbag system comprising the airbag described above, wherein the airbag system may comprise conventional equipment well known to those skilled in the art.

The airbag may be a bumper type airbag or the like outside the vehicle. The external type bumper airbag mounted on the outside of the vehicle serves to buffer shocks applied to the pedestrian or the vehicle itself.

In particular, the aramid fabric of the present invention can be effectively used for an external type bumper airbag mounted on a vehicle exterior bumper or the like by securing both high mechanical properties and excellent flexibility. An example of such a bumper airbag is shown in Fig. 2, the bumper airbag device 201 includes an airbag 203 housed in a front bumper 202 of the vehicle 200 in a contracted state, and an inflator (not shown) connected to the airbag 203 inflator 204. When the airbag apparatus 201 is operated, the inflator 204 generates gas at a high temperature and a high pressure so that an airbag 203 to which high temperature and high pressure gas is supplied is provided to the front of the front bumper 202 Lt; / RTI > As a result, the impact from the vehicle colliding with the front bumper 202 and the impact of the pedestrian can be mitigated. In the above-described example, the airbag apparatus including the aramid fabric of the present invention is housed in the front bumper. However, if necessary, the airbag apparatus may be mounted on a rear bumper of a vehicle or the like.

In the present invention, matters other than those described above can be added or subtracted as required, and therefore, the present invention is not particularly limited thereto.

INDUSTRIAL APPLICABILITY According to the present invention, an aramid fiber is used to weave a fabric to a specific cover factor range, thereby providing an airbag fabric having excellent mechanical properties and flexibility and foldability, and a vehicle airbag comprising the same.

These aramid fabrics not only provide superior shape stability, mechanical properties and air-blocking effect, but also have excellent foldability and flexibility, thereby remarkably improving the retention of the automobile when mounted, and at the same time, Thereby minimizing the risk of occupant safety.

In particular, the aramid fabric according to the present invention can be suitably used for the manufacture of a bumper type air bag cushion which can be mounted on the outside of a vehicle to buffer a high impact force.

1 shows a general airbag system.
2 is a view showing a vehicle having an exterior type bumper airbag mounted outside the vehicle.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example  1 to 8

Fabrics for airbags were made using aramid fibers under the process conditions shown in Table 1 below.

First, aramid fibers were used to weave raw fabrics for airbags through rapier looms. The raw fabric for the airbags was prepared by repeating the refining and the heat treatment process twice continuously. The non-coated fabric thus prepared was directly used as a cloth made of fabric for airbag cushion (Examples 2, 3, 5, 6 and 8), or the liquid silicone rubber A silicone coating material coated with a knife over roil coating method was used as a cloth material for an airbag cushion using a silicone coating agent based on LSR resin (Examples 1, 4, 7 ).

The fabric was cut using a laser cutter, and the fabric was stitched and bonded under the sewing conditions shown in Table 1 below to produce an airbag cushion.

At this time, the yarn type, the weaving type, the coating component and the coating amount of the airbag fabric, the type of the sewing machine and the sewing method are shown in Table 1 below. Here, the cover factor (CF) of the fabric is calculated by the following equation (1). The remaining conditions were in accordance with the usual conditions for manufacturing the airbag cushion.

[Equation 1]

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Yarn type Ara
mid Ara
mid Ara
mid Ara
mid Ara
mid Ara
mid Ara
mid Ara
mid Inclined fineness (de) 840 840 840 600 600 600 400 400 Weft fineness (de) 840 840 840 600 600 600 400 400 Inclined density (th / inch) 28 28 32 28 28 35 44 44 Weft density (th / inch) 28 28 32 28 28 35 44 44 Cover Pater (CF) 1623 1623 1855 1372 1372 1715 1760 1760 Whether coating U radish radish U radish radish U radish Coating material silicon - - silicon - - silicon - Coating amount (gsm) 60 - - 40 - - 40 - Type of sewing machine nylon nylon nylon nylon nylon nylon nylon nylon Sewing thread fineness (de) 1,260 1,260 1,260 1,260 1,260 1,260 1,260 1,260 Sewing stitch number (th / 100mm) 35 35 35 35 35 35 35 35

Various properties of the airbag cushions prepared according to Examples 1 to 8 were measured by the following methods, and the measured physical properties are summarized in Table 2 below.

(a) Tensile strength and cutting elongation

The specimens were cut from the airbag fabric and fixed to the lower clamp of the tensile strength measuring device according to the American Society for Testing and Materials ASTM D 5034, and the strength and elongation at break of the airbag fabric specimen were measured while moving the upper clamp upward.

(b) Lecture chart

The lubrication of the fabric was measured by a Circular Bend method using a lubrication measuring device according to the American Society for Testing and Materials ASTM D 4032. In addition, the cantilever method can be applied to the cantilever measurement method, and the cantilever can be measured by measuring the bending length of the cantilever using a cantilever measuring device, which is a test bench having a predetermined angle of inclination to bend the fabric.

(c)

The finish of the fabric for the airbag was measured according to the International Organization for Standardization ISO 2286-3.

(d) Air permeability

According to ASTM D 737 of the American Society for Testing and Materials (ASTM D 737), the airbag fabric was allowed to stand at 20 ° C and 65% RH for at least one day, and the amount of air having a pressure of 125 Pa passing through a circular cross section of 38 cm ² was measured.

(e) Sealant strength

The sewing part specimen of the airbag cushion was fixed to the lower clamp of the measuring device according to the method of ASTM D 1683 of the American Society for Testing and Materials, and the upper clamp was moved upward to measure the seam strength when the airbag cushion specimen was broken.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Tensile strength (kgf / 10 mm) 233 228 262 203 201 218 182 191 Lecture (kgf) 1.32 0.79 1.02 1.00 0.85 1.11 1.26 0.87 Fillet (mm) 0.32 0.27 0.29 0.24 0.22 0.23 0.19 0.17 Air permeability (cfm) 0.00 1.71 1.60 0.00 2.88 2.34 0.03 0.81 Seal strength (kgf / 20mm) 215 230 280 232 211 229 191 164

Comparative Example  1 to 8

The airbag fabric of Comparative Examples 1 to 8 and the airbag cushion using the same were prepared in the same manner as in Examples 1 to 8 except for the conditions described in Table 3 below.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Yarn type nylon nylon Ara
mid Ara
mid Ara
mid Ara
mid nylon nylon Inclined fineness (de) 630 630 400 400 840 840 420 420 Weft fineness (de) 630 630 400 400 840 840 420 420 Inclined density (th / inch) 41 41 24 24 41 41 46 48 Weft density (th / inch) 41 41 24 24 41 41 46 48 Cover Pater (CF) 2058 2058 960 960 2377 2377 1885 1967 Whether coating U radish U radish U radish U radish Coating material silicon - silicon - silicon - silicon - Coating amount (gsm) 25 - 25 - 25 - 25 - Type of sewing machine nylon nylon nylon nylon nylon nylon nylon nylon Sewing thread fineness (de) 1260 1260 1260 1260 1260 1260 1260 1260 Sewing stitch number (th / 100mm) 35 35 35 35 35 35 35 35

Various properties of the airbag cushions prepared according to Comparative Examples 1 to 8 were measured as described above, and the measured physical properties are summarized in Table 4 below.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Tensile strength (kgf / 10 mm) 128 120 92 90 361 358 90 100 Lecture (kgf) 1.31 1.12 0.48 0.35 1.82 1.62 1.0 0.7 Fillet (mm) 0.37 0.35 0.13 0.11 0.48 0.46 0.28 0.30 Air permeability (cfm) 0.00 2.0 5.1 12 0 1.2 0 2.0 Seal strength (kgf / 20mm) 120 113 108 110 250 248 108 104

As shown in Table 2, the air bag fabrics of Examples 1 to 8, in which the cover factor was optimized to the optimum range by using the aramid yarn, were remarkably improved in the lubrication degree from 0.79 to 1.32 kgf and were compactly folded It can be seen that there is no problem in foldability at all. At the same time, the fabric according to Examples 1 to 8 exhibits excellent mechanical properties with a tensile strength of 182 to 262 kgf / 10 mm and a seam strength of 164 to 280 kgf / 20 mm, It was confirmed that there was no problem at all.

On the other hand, as shown in Table 4, it was confirmed that the airbag fabrics of Comparative Examples 1 and 2 using nylon yarn as conventional did not satisfy these characteristics. In particular, it can be seen that the airbag fabrics of Comparative Examples 1 and 2 have a tensile strength significantly lowered to 128 kgf / 10 mm and 120 kgf / 10 mm, respectively, and there is a limit in expressing performance outside the vehicle. In addition, the airbag fabrics of Comparative Examples 3 and 4 had a problem that although the aramid yarn was used, the coating agent leaks to the backside due to a too low cover factor, and the tensile strength of the fabric was 92 kgf / 10 mm and 90 kgf / 10 mm, respectively, and the seam strength is also significantly reduced to 108 kgf / 20 mm and 110 kgf / 20 mm, respectively. On the other hand, the airbag fabrics of Comparative Examples 5 and 6 had an excessively high cover factor, so that the fabric lubrication was poor at 1.82 kgf and 1.62 kgf, respectively. It is not possible to store them in a space of a predetermined size. On the other hand, in the case of Comparative Examples 7 and 8, the mechanical properties such as tensile strength and seam strength are rapidly lowered, so that the airbag itself may be damaged or ruptured when inflated by the inflator gas at high temperature and high pressure.

Claims (9)

An outer air bag for a vehicle comprising an aramid fiber and having an aramid fabric having a cover factor of 1200 to 1855 as shown in the following calculation formula 1 and having a liner degree of 0.4 kgf to 1.4 kgf according to the American Society for Testing and Materials ASTM D 4032, .
[Equation 1]

The method according to claim 1,
Wherein the warp fineness and the weft fineness comprise aramid fabrics of 200 to 1,000 denier, respectively.
The method according to claim 1,
Wherein the warp density and weft density are each between 20 and 55 th / inch.
The method according to claim 1,
A vehicle exterior air bag comprising an aramid fabric having a lap sheeting of 0.79 to 1.32 kgf according to the American Society for Testing and Materials Standards ASTM D 4032 method.
The method according to claim 1,
A vehicle exterior air bag comprising an aramid fabric having a thickness of from 0.10 mm to 0.45 mm as measured by the International Organization for Standardization ISO 2286-3 method.
The method according to claim 1,
A vehicle external air bag comprising an external vehicle air bag comprising an aramid fabric having a tensile strength of 150 kgf / 10 mm or greater as measured by the American Society for Testing and Materials ASTM D 5034 method.
The method according to claim 1,
Exterior vehicle airbags comprising an aramid fabric having a stiffness of at least 150 kgf / 20 mm as measured by the American Society for Testing and Materials Standards ASTM D 1683 method.
The method according to claim 1,
Wherein the airbag is a bumper type airbag.
The method according to claim 1,
Wherein the airbag is mounted to a front bumper or a rear bumper.

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