KR20160038512A - Air bag cushion cover of non-woven fabric - Google Patents

Abstract

The present invention relates to a non-woven fabric cover for fixing an airbag cushion and, more specifically, relates to a non-woven fabric cover for fixing an airbag cushion, wherein a portions opened when an airbag cushion is deployed is composed of a slit cutting unit and a connection joint, and a non-open portion is composed of a specific sewing bonding portion. According to the present invention, the non-woven fabric cover for fixing an airbag cushion is hardly torn as a thread is stretched unlike a weaving fabric, and further, strength of the non-woven fabric cover for fixing an airbag cushion is higher than that of a packaging film to perform stable performance. Therefore, a folded state of a vehicle airbag can be maintained, and after the airbag is deployed, the non-woven fabric cover for fixing an airbag cushion is torn with appropriate strength not to interfere with the deployment.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an air bag cushion,

The present invention relates to a nonwoven cover for fixing an airbag cushion, and more particularly, to a cover for fixing an airbag cushion for housing an airbag cushion for an automobile.

Generally, an air bag is used to detect a collision shock 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 a shock sensor, The airbag cushion system according to the present invention is a device that protects a driver and a passenger by inflating and expanding the airbag cushion.

1, a typical airbag cushion system includes an inflator 121 that generates gas by ignition of a primer 122, an airbag cushion 124 that is inflated and deployed toward the driver of the driver's seat by the generated gas, An airbag cushion 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 igniter for igniting the primer 122 of the inflator 121 And an electronic control module (110).

The airbag cushion system configured as described above senses an impact in the impact sensor 130 and transmits a signal to the electronic control module 110 when the vehicle collides head-on. 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 airbag cushion 124 through rapid gas generation.

The airbag cushion 124 inflated and deployed partially absorbs the impact load caused by the collision while contacting the front upper body of the driver, and the airbag cushion 124, which is inflated while the driver's head and chest are moved forward due to inertia, In the event of a collision, the gas of the airbag cushion 124 is rapidly discharged to the discharge hole formed in the airbag cushion 124, and is buffered on the front portion of the driver. 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 cushion used in an automobile is manufactured in a certain shape, and then mounted on a handle or the like of the automobile in a folded state to minimize its volume. At this time, in order to maintain the folded state of the airbag cushion, the cover is covered with the cushion. In order to assemble and maintain the car airbag cushion like this, the cover of the automobile airbag cushion

A conventional airbag cushion fixing cover is made of the same material as polyamide (nylon 66), which is the main material of an automobile airbag cushion, so as to facilitate the manufacturing process of the airbag system. In order to facilitate tearing, .

However, the nylon 66 fabric used as the main material of the automobile airbag cushion is expensive and has a high tensile strength, so that the airbag cushion can not be smoothly deployed when the cushion is used as a cover of a car airbag cushion. That is, in the case where there is a portion with less incision, the airbag cushion may not be deployed in time, or may not be operated, resulting in a fatal result.

In order to solve this problem, the gap of the incised portion of the cover becomes large, and the interval of the connection node maintaining the shape of the cover between the incised portions has to be minimized. However, when the distance between the connection nodes of the automobile airbag cushion fixing cover is minimized, the airbag cushion can not be cut by the laser cutter or the blade cutter, There is no problem. Particularly, there is a problem that workability is deteriorated when the automobile airbag cushion is directly mounted on a blowing device or an automobile. Therefore, when the fabric woven in plain weave is applied to the cover for fixing the airbag cushion, only the warp or weft yarn is straightly connected to the connecting knob portion so that the folded state of the airbag cushion can not be maintained and the yarn is stretched and eventually torn high portential.

In order to solve the above-mentioned problems, some products use a cover for fixing an air bag cushion using a packaging film. However, since the tensile strength of the packaging film is not sufficient, Tearing in contact with the equipment prevented maintenance of the shape, which is the role of the cover for fixing the cushion of the automobile, and the assemblability to be mounted on the automobile was often poor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a nonwoven cover for fixing a nonwoven airbag cushion which is excellent in the performance of maintaining the folded state of the airbag cushion and is capable of expanding the airbag cushion with appropriate strength.

The airbag cushion is made of polyethylene terephthalate (PET) nonwoven fabric. The airbag cushion includes a portion that is opened and a portion that is not opened when the airbag cushion is deployed. A portion that is opened when the airbag cushion is deployed is formed with a slit cut- And a portion of the airbag cushion not to be opened when the airbag cushion is deployed is joined by a sewing method with a stitch number of 10 to 35/100 mm.

Hereinafter, a nonwoven cover for fixing an airbag cushion according to a specific embodiment of the present invention 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.

In the present invention, the term "cover for fixing the airbag cushion" refers to an airbag cushion covering an airbag cushion for folding the airbag cushion to maintain the folded shape of the airbag cushion until the airbag is folded.

Also, in the present invention, the machine direction of the nonwoven fabric refers to the direction in which the web opened on the tray is produced during the production of the nonwoven fabric.

The inventors of the present invention have found that the airbag cushion can be opened at the time of deployment of the airbag cushion in the cover for fixing the airbag cushion by a specific slit incision portion and connection portion, And it is possible to improve the deployment performance of the airbag cushion, thereby completing the present invention.

According to one embodiment of the present invention, there is provided a nonwoven cover for fixing an airbag cushion made of a polyethylene terephthalate (PET) nonwoven fabric. The airbag cushion fixing nonwoven cover includes a portion to be opened and a portion to be non-opened when the airbag cushion is deployed, and a portion to be opened when the airbag cushion is deployed is formed with a slit incision portion and a connection node, And the non-opened portion of the airbag cushion is unfolded when the airbag cushion is deployed is joined by a sewing method with a stitch number of 10 to 35/100 mm.

As a general airbag cushion fixing cover, there is used a nylon 66 flat fabric or a wrapping wrap formed with a cut-off portion with a certain length. In the present invention, a cover for fixing an airbag cushion is manufactured using a nonwoven fabric.

In particular, the present invention is characterized by using a polyethylene terephthalate (PET) nonwoven fabric having a low tensile strength and a low tensile strength as compared with a nylon 66 fabric as a cover for fixing an airbag cushion. The present invention also relates to a method of developing an air bag cushion finished product in the production of an air bag cushion cover, in which a slit is given to the nonwoven fabric itself at regular intervals to thereby untwist the periphery of the sewed portion .

To this end, the present invention uses a polyethylene terephthalate nonwoven fabric as a cover for fixing an airbag cushion. The kind of the nonwoven fabric is not particularly limited, but a spunbond nonwoven fabric can be preferably used. The polyethylene terephthalate nonwoven fabric to be used in the present invention can be prepared by using a conventional nonwoven fabric manufacturing method. The thickness of the polyethylene terephthalate nonwoven fabric is not particularly limited, but it is preferably 0.25 to 0.35 mm, more preferably 0.27 to 0.33 mm, measured according to American Society for Testing and Materials Association (ASTM) D 1777 . The thickness of the nonwoven fabric may not be sufficient to exhibit a sufficient tensile strength, so that the folded airbag cushion can not be effectively secured. The thickness of the nonwoven fabric may be 0.25 mm or more and 0.35 mm or less in terms of improving the airbag deployment performance.

The cover for fixing the airbag cushion preferably has a tensile strength of 15 to 45 kgf / 5 cm as measured according to American Society for Testing and Materials Association (ASTM) D 5035. If the tensile strength exceeds 45 kgf / 5 cm, the deployment of the airbag may be impeded, and if the tensile strength is less than 15 kgf / 5 cm, the performance of maintaining the folded state of the airbag may be deteriorated. More specifically, the tensile strength measured in a direction parallel to the machine direction during production of the nonwoven fabric may be 30 to 45 kgf / 5 cm and the tensile strength measured in the direction perpendicular to the machine direction may be 15 to 45 kgf / More preferably 15 to 30 kgf / 5 cm.

In the nonwoven fabric cover for fixing the airbag cushion of the present invention, the portion of the airbag cushion which is opened when the airbag cushion is deployed may be disposed at a position facing the inflator for ejecting high-pressure gas in the event of a collision of the vehicle.

The airbag cushion may include a slit incision portion and a connection portion. The slit incision portion and the connection portion may be formed in a shape that is continuously and repeatedly formed along the longitudinal direction of a portion opened when the airbag cushion is deployed. .

In particular, the nonwoven cover for fixing the airbag cushion of the present invention may include a cutout 22 and a connecting node 23 as shown in FIG. 3, wherein the cutout 22 has a length of 0.5 to 2.0 cm And more preferably 0.7 to 1.5 cm in length. In addition, the connection node 23 preferably has a length of 0.5 to 1.0 cm, more preferably a length of 0.6 to 0.8 cm. If the length of the incision 22 is less than 0.5 cm or the length of the connection node 23 is more than 1.0 cm then the deployment of the airbag may be impeded and if the length of the incision 22 exceeds 2.0 cm Or when the length of the connection node 23 is less than 0.5 cm, the performance of fixing the folded airbag cushion may be deteriorated.

At this time, considering the normal developing shape of the airbag and the developing time of the airbag, the nonwoven cover preferably has a slit portion in a lengthwise direction of 60% to 90%, preferably 65% to 85% It can be a form to occupy. Further, it is preferable that the connection node 23 has a length of 1 to 7 mm in consideration of the deployment of the airbag. For example, the nonwoven cover for fixing the airbag cushion may include an incision having a slit of 5 to 25 mm, more preferably 10 to 20 mm, per 1 to 7 mm spaced connection node in the longitudinal direction.

In the nonwoven fabric cover, the direction in which the slit cut portion is formed is not limited to a specific direction, and the direction perpendicular to the machine direction of the nonwoven fabric, the direction parallel to the machine direction, Or other diagonal directions.

The nonwoven fabric to be used in the present invention can be produced and used according to a conventional method for producing a nonwoven fabric, and one of ordinary nonwoven fabrics satisfying the conditions of the cover for fixing the airbag cushion can be selected and used.

The cut portion formed on the nonwoven fabric can be cut using a laser cutter or a blade cutter.

In the present invention, the portion of the airbag cushion that is opened when the airbag cushion is deployed may have a seam strength of 1 to 6 kgf / inch, preferably 1.5 to 5.5 kgf / inch, as measured by the American Society for Testing and Materials Association standard ASTM D 1683. If the tensile strength at the portion of the airbag cushion that is opened when the airbag cushion is deployed is less than 1 kgf / inch, the slit portion may easily tear during airbag assembly. If the airbag cushion is more than 6 kgf / inch, The abnormal portion may be torn and the deployed shape of the airbag may be abnormal or the deployment timing of the airbag may be abnormally made. In addition, the portion of the airbag cushion which is opened when the airbag cushion is deployed may have an elongation of 5 to 20%, preferably 7 to 18% as measured by the American Society for Testing and Materials Association standard ASTM D 1683 method. The elongation of the portion of the airbag cushion which is opened when the airbag cushion is deployed may be 5 or more on the side where the elongation of the connecting portion of the slit is too low to easily rupture during manufacture and storage, Is too high to expand in the unfolded, unfolded, connected and can be developed in the abnormal direction can be less than 20%.

In the nonwoven cover for fixing the airbag cushion of the present invention, the non-opened portion of the airbag cushion when deployed may be disposed on an extension line at the same position as the inflator ejecting high pressure gas in the event of a collision of the vehicle. The inflator is disposed on an extension line at the same position as the inflator. The inflator extends up to a position not to form a diagonal line facing the inflator. Quot;

The un-opened portion of the airbag cushion is joined by a sewing method using a sewing thread. The sewn connecting portion may be further joined with an adhesive, or may be bonded by heat or ultrasonic treatment.

When the non-opened portion of the airbag cushion is unfolded using the sewing thread, the number of stitches of the sewing portion, that is, the number of stitches per 100 mm of the sewing portion is 10 to 35/100 mm, preferably 15 to 30 / mm. < / RTI > At this time, if the number of stitches of the sewn joint is less than 10/100 mm, the strength of the sewn portion is too weak, and there is a problem that the sewn portion breaks at the time of manufacturing or expanding. There is a problem that the nonwoven fabric is damaged.

In addition, an effective sewing method can be selected according to the use of each portion of the sewn joint portion of the un-opened portion when the airbag cushion is deployed, and the sewing method such as a single lock, a double lock, a single chain, To adjust the number of stitches.

The joint portion of the un-opened portion of the airbag cushion may have a seam strength of 6 to 35 kgf / inch, preferably 8 to 33 kgf / inch, as measured by the American Society for Testing and Materials Association standard ASTM D 1683 . Also, the elongation measured by the method of American Society for Testing and Materials Standards ASTM D 1683 may be 10% to 60%, preferably 15% to 55%. It is preferable that the sewing joint portion of the non-open portion according to the present invention maintains the strength of the sewing portion in the optimum range and maintains the sealing strength in the above range in terms of effectively maintaining the assembly and state of the airbag cushion.

As described above, the nonwoven fabric cover for fixing the airbag cushion of the present invention may be disposed at a different position from a portion opened and unfrozen when the airbag cushion is deployed. More specifically, the portion of the airbag cushion that is opened when the airbag cushion is deployed is disposed at a position facing the inflator that ejects high-pressure gas in the event of a collision of the vehicle, so that an effective cushion cover can be broken. The non-opening portion can be formed by sewing or the like, and the assembly and storage state of the cushion can be effectively maintained.

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.

The airbag cushion fixing nonwoven cover according to the present invention is less likely to be torn by stretching the yarn unlike the woven fabric, and has a higher strength than the packaging film, thereby achieving stable performance.

Accordingly, there is an advantage that the folded state of the automobile airbag is maintained, and thereafter, the inflated airbag is torn to an appropriate strength at the time of deployment of the airbag.

1 is a schematic view showing a general air bag system.
2 is an overall schematic view of a nonwoven cover for fixing an airbag cushion manufactured according to Embodiment 2 of the present invention.
3 is a schematic view showing a cut-away portion and a connection node of a nonwoven cover for fixing an airbag cushion.
4 is a schematic view showing an apparatus for measuring tensile strength of a cover for fixing an airbag cushion.

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

A cutter of 1.9 cm in length and a cutter of 0.6 cm in length at an angle of 90 ° with respect to the machine direction of the nonwoven fabric by using a laser cutter in a polyethylene terephthalate (PET) spunbonded nonwoven fabric (trade name: K2070NW, Kolon Industries Co., A connection node was formed to manufacture a cover for fixing the airbag cushion. At this time, a portion of the airbag cushion that is opened when the airbag cushion is deployed is disposed at a position facing the inflator that ejects high-pressure gas when the vehicle collides. In the non-woven cover for fixing the airbag cushion, the non-opened portions other than the open portion were sewn together by applying a sewing method of 15 to 30 stitches / 100 mm in a single lock using a polyester sewing thread.

Comparative Example 1

420 denier nylon 66 yarn was used to fabricate a plain weave having a weaving density of 46 x 46 EA / inch.

RTV silicone rubber (Rhodia) 28 g / m < ² >, coated with a blade cutter, cut in a direction parallel to the weft, 6.6 cm in length and 0.3 cm in length.

Comparative Example 2

A cover for fixing the airbag cushion was made of a polypropylene film for packaging having a thickness of 0.03 mm.

Test Example 1

The tensile strength of the airbag cushion fixing cover manufactured in Example 1 and Comparative Examples 1 and 2 was measured by the American Society for Testing and Materials Association (ASTM) D 5035 method.

The samples used for the measurement are as shown in Table 1 below.

division material Sample Size The longitudinal direction of the sample Sample 1 Example 1 PET nonwoven 5 cm x 10 cm Nonwoven machine direction Sample 2 Example 1 PET nonwoven 5 cm x 10 cm Nonwoven machine direction
Vertical direction Sample 3 Comparative Example 1 66 ply nylon fabric 2.5 cm x 10 cm Weft direction of fabric Sample 4 Comparative Example 2 PP film 2.5 cm x 10 cm No orientation

Each sample prepared as shown in Table 1 was cut so as not to include an incision portion, and the clamp of the tensile strength measuring device was attached to each sample in the longitudinal direction thereof. 4 is a schematic view showing an apparatus for measuring tensile strength of a cover for fixing an airbag cushion.

As shown in Fig. 4, the lower clamp 32b of the tensile strength measuring apparatus equipped with the sample 31 is fixed, and the upper clamp 32a is moved upward, and the strength when the airbag cushion fixing cover 31 is broken Strength. Other conditions are in accordance with the American Society for Testing and Materials Standards (ASTM) D 5035.

Further, in the nonwoven cover for fixing the airbag cushion, the seam strength and elongation were measured with respect to the opening portion of the slit incision portion and the non-opening portion of the sewing connection portion. First, the 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 and elongation at break of the airbag cushion specimen. Table 2 shows the measured breaking strength and elongation.

division Slit opening Sewing non-opening area Seam strength
(kgf / inch) Elongation (%) Seam strength
(kgf / inch) Elongation (%) Sample 1 Example 1 8.3 8.6 20.8 19.2 Sample 2 Example 1 4.5 14.8 10.5 29.2 Sample 3 Comparative Example 1 40.9 37.7 128.2 42.1 Sample 4 Comparative Example 2 N.D. N.D. N.D. N.D.

Test Example  2

The thicknesses of Samples 1 to 4 used in Test Example 1 were measured by the American Society for Testing and Materials Association (ASTM) D 1777 method.

Tensile strength and thickness of Samples 1 to 4 measured by the above Test Examples 1 and 2 are shown in Table 3 below.

division The tensile strength thickness Sample 1 Example 1
(Machine direction) 36 kgf / 5 cm 0.28 mm Sample 2 Example 1
(Vertical direction) 18 kgf / 5 cm 0.28 mm Sample 3 Comparative Example 1
(Plain weave) 200 kgf / 2.5 cm 0.28 mm Sample 4 Comparative Example 2
(film) 2 kgf / 2.5 cm 0.03 mm

As shown in Table 3, the airbag cushion fixing cover of Example 1 using the polyethylene terephthalate nonwoven fabric of Samples 1 and 2 had lower tensile strength than the airbag cushion fixing cover of Comparative Example 1 using the nylon 66 fabric of Sample 3 It is not disturbed when the airbag is deployed, and it has a superior tensile strength to the packaging film of Comparative Example 2 using the polypropylene film of Sample 4, so that the performance of maintaining the folded state of the airbag cushion is excellent.

Claims (15)

A polyethylene terephthalate (PET) nonwoven fabric,
Includes a portion to be opened and a portion to be non-opened when the airbag cushion is deployed,
Wherein a portion of the airbag cushion that is opened when the airbag cushion is deployed is formed with a slit incision portion and a connection node,
Wherein the non-opened portion of the airbag cushion is joined by a sewing method with a stitch number of 10 to 35/100 mm. The method according to claim 1,
Wherein a portion of the airbag cushion that is opened when the airbag cushion is deployed is disposed at a position facing the inflator that ejects a high-pressure gas in the event of a vehicle collision. The method according to claim 1,
Wherein a portion of the airbag cushion that is not opened when the airbag cushion is deployed is disposed on an extension line at the same position as an inflator that ejects a high-pressure gas when the vehicle collides. The method according to claim 1,
Wherein a slit incision part and a connection part are continuously and repeatedly formed in a longitudinal direction of a portion of the airbag cushion which is opened when the airbag cushion is deployed. The method according to claim 1,
Wherein a portion of the airbag cushion to be opened when the airbag cushion is deployed has a seam strength of 1 to 6 kgf / inch as measured by the method of ASTM D 1683 of the American Society for Testing and Materials. The method according to claim 1,
Wherein the portion of the airbag cushion to be opened when the airbag cushion is deployed is an elongation of 5% to 20% as measured by the method of ASTM D 1683 of the American Society for Testing and Materials. The method according to claim 1,
Wherein the slit incision is 0.5 to 2.0 cm, and the connection node is 0.5 to 1.0 cm. The method according to claim 1,
Wherein the slit incision portion occupies 60% to 90% in a longitudinal direction of a portion to be opened when the airbag cushion is deployed. The method according to claim 1,
Wherein the non-opened portion of the airbag cushion is joined by one or more sewing methods selected from the group consisting of a single lock, a double lock, a single chain, and a double chain. The method according to claim 1,
Wherein the non-opened portion of the airbag cushion is joined with one or more types of sewing yarn selected from the group consisting of a nylon yarn, a polyester yarn, a polyolefin yarn, and an aramid yarn. The method according to claim 1,
The non-woven cover for fixing the airbag cushion has a seam strength of 6 to 35 kgf / inch as measured by the method of American Society for Testing and Materials ASTM D 1683 when the airbag cushion is deployed. The method according to claim 1,
The non-woven portion for unfolding the airbag cushion has an elongation of 10% to 60% as measured by the method of ASTM D 1683 of the American Society for Testing and Materials. The method according to claim 1,
A nonwoven cover for fixing an airbag cushion having an average thickness of 0.28 to 0.34 mm as measured according to American Society for Testing and Materials Association (ASTM) D 1777. The method according to claim 1,
A nonwoven cover for fixing an airbag cushion having a tensile strength of 30 to 45 kgf / 5 cm measured in the machine direction of a nonwoven fabric according to the American Society for Testing and Materials Association (ASTM) D 5035. The method according to claim 1,
A nonwoven cover for fixing an airbag cushion having a tensile strength of 15 to 45 kgf / 5 cm measured in a direction perpendicular to the machine direction of the nonwoven fabric according to American Society for Testing and Materials Association (ASTM) D 5035.

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