KR101984943B1 - Fabric for airbag and preparation method thereof - Google Patents

Abstract

More particularly, the present invention relates to a fabric for an air bag comprising a high tenacity polyethylene yarn having a tensile strength of 12 g / d or more and a cutting elongation of 2% to 15%, a method for producing the same, Lt; / RTI >
The airbag fabric of the present invention is excellent in mechanical properties such as toughness and tear strength by using a high tenacity polyethylene yarn which is light and excellent in mechanical properties, and at the same time can be lightweight with a low weight, Energy-absorbing, and air-tightening effects and minimizes the impact on passengers, thereby safeguarding occupants.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fabric for airbags,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fabric for an air bag, and more particularly, to a fabric for an air bag including a high strength polyethylene yarn and a method of manufacturing the same.

Generally, the airbag detects a collision shock applied to the vehicle at the time of frontal or side collision at a speed of about 40 km / h or more at a speed of about 40 km / h by the impact sensor, and then explodes a gunpowder to supply gas into the airbag cushion to inflate , And protects passengers.

The required items for the airbag are the energy absorbency of the fabric to prevent the damage and rupture of the cushion which may be generated from the high temperature-high pressure inflator gas when the airbag is deployed, the low air permeability for smooth deployment of the airbag cushion, And flexibility to reduce costs.

Particularly, as the interior of the vehicle becomes complicated and the storage space becomes narrower, the space where the airbag is located is also gradually reduced, so that it is required to develop a fabric for an airbag having excellent folding ability. As a result, the weight of various parts is regulated. As cushions made of nylon yarn and polyester yarn, which are used for existing airbags, have a limitation in weight reduction, the same level of properties It is necessary to develop fabrics that are lightweight.

Conventionally, a method of lowering the fineness of the yarn or lowering the density of the fabric is used to solve the weight problem of the fabric. However, there is a limit in the reduction of the weight through the above-mentioned method, and when the fabric is used by the above method, the mechanical properties of the fabric significantly deteriorate, so that the applied airbag cushion can not withstand high temperature and high pressure inflator pressure.

Accordingly, it is an object of the present invention to provide a textile fabric capable of achieving a vehicle light weight by minimizing flexibility, lubrication, and weight for reducing impact applied to a passenger while maintaining excellent mechanical properties and air- Research on development is needed.

The present invention provides a fabric for airbags employing a high strength polyethylene yarn excellent in mechanical properties while ensuring light weight and foldability, and a method of manufacturing the same.

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

The present invention provides a fabric for an air bag comprising a polyethylene yarn having a tensile strength of 10 g / d or more and a cut elongation of 2% to 15%.

In the airbag fabric of the present invention, the polyethylene-based raw material may include a repeating unit represented by the following formula (1).

[Chemical Formula 1]

The present invention also relates to a method for producing an airbag comprising the steps of weaving a raw material for an airbag with a polyethylene yarn having a tensile strength of 10 g / d or more and a cut elongation of 2% to 15%, refining the raw paper for the airbag weaving, A method of manufacturing a fabric for an airbag comprising the step of tentering a fabric.

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

Hereinafter, a fabric for an air bag according to a specific embodiment of the invention, a manufacturing method thereof, and a vehicle air bag including the same 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 fabric for the airbag refers to a fabric or a nonwoven fabric used for manufacturing an airbag for an automobile. Typical airbag fabrics include nylon 66 flat fabric woven with a rapier loom, an air jet loom, a waterjet loom, 66 nonwoven fabric is used, the fabric for airbag of the present invention is characterized by being lightweight and having good basic properties such as shape stability, toughness, air permeability, and lubrication by using a high-strength linear polyethylene type yarn.

Particularly, conventionally, nylon yarn and polyester yarn have been used as raw materials for airbags, but the specific gravity of nylon yarn is 1.14 g / cm ³ and the specific gravity of polyester yarn is as high as 1.38 g / cm ³ , There is a problem that the weight limit can not be overcome when the density or the density of the fabric is increased.

However, when conventional polyethylene-based yarns are applied to yarns for airbags instead of conventional polyamide fibers such as nylon 66, mechanical properties such as tensile strength of yarns related to energy absorbency are very low. In addition, when the conventional polyethylene yarn is applied, since the cushion is applied as a cushion for an air bag due to a decrease in physical properties and a low heat resistance at the time of long aging due to a low molecular weight, cushion damage is significant, Should be able to do. In addition, when a conventional polyethylene yarn is used as a fabric for an airbag and mounted on an automobile, the cushion is severely damaged in various modes of testing, and the internal pressure maintenance performance deteriorates due to a gas leak of the cushion The development deviation of the cushion is also generated, which is difficult to apply.

Accordingly, the present invention uses a high-strength linear polyethylene yarn to optimize the range of properties such as tensile strength and cutting elongation of the yarn, thereby minimizing the weight of the fabric, thereby achieving vehicle weight reduction while maintaining excellent mechanical properties and air- So that it is possible to obtain an improved physical property improvement effect as a fabric for an airbag.

According to one embodiment of the invention, there is provided a fabric for airbags comprising high tenacity polyethylene yarn. The present invention provides a fabric for an air bag comprising a polyethylene yarn having a tensile strength of 10 g / d or more and a cut elongation of 2% to 15%.

In particular, the present invention is characterized by using a linear polyethylene yarn including the repeating unit represented by the formula (1).

[Chemical Formula 1]

In the present invention, polyethylene (PE) is a linear polymer having ethylene repeating units as shown in the above formula (1), and has a polymer structure of ISOTATIC, SYNDIOTATIC, ATATIC Can be used. The above polyethylene (PE, polyethylene) has characteristics of physical properties such as high strength, low specific gravity, and low weight.

The polyethylene-based fiber in the fabric for airbags may have a tensile strength of 10.0 g / d or more, or 10 to 18 g / d, preferably 11 g / d or more, more preferably 12 g / d or more. The tensile strength of the yarn may be greater than or equal to 10 g / d so as to withstand high temperature and high pressure conditions during deployment of the airbag. In addition, the tensile strength of the polyethylene-based fiber is preferably not more than 18 g / d in terms of preventing stiffness of the fabric for airbags and lowering of folding ability.

In addition, the polyethylene-based fibers may have a cut elongation of 2% to 15%, preferably 2.5% to 13%, and more preferably 3% to 10%. If the cutting elongation of the yarn is less than 2%, the modulus of the yarn is high, resulting in a stiff fabric. If the elongation at break of the polyethylene-based fibers is more than 15%, the elongation of the fabric itself is increased, which is not suitable for varying the development speed at the time of deployment of the airbag.

The polyethylene-based yarn may have a dry heat shrinkage of 1.0% to 10%, preferably 1.5% to 9%, more preferably 2.0% to 8.0%, and the dry heat shrinkage ratio of the yarn , It may be 1.0% or more, and it may be 10% or less in terms of the shape stability when the airbag cushion is deployed.

The polyethylene-based yarn may have a number average molecular weight of 200,000 or more, or 200,000 to 1,000,000, preferably 220,000 or more, more preferably 250,000 or more, and the number average molecular weight of the yarn may be a tensile strength physical property To 200,000 or more.

The polyethylene-based raw material may have a specific gravity of 0.99 g / cm ³ or less, or 0.91 to 0.99 g / cm ³ , preferably 0.985 g / cm ³ or less, more preferably 0.98 g / cm ³ or less. In the present invention, the polyethylene-based yarn maintains a significantly lower specific gravity than conventional nylon yarn and polyester yarn, thereby optimizing the fiber fineness and weaving density when manufacturing the fabric for an airbag, thereby achieving excellent mechanical properties, The entire vehicle tendency can be achieved at the same time.

In the airbag fabric of the present invention, the polyethylene fiber may have a fineness of 300 to 600 denier, preferably 320 to 580 denier. In addition, the number of filaments of the polyethylene-based fibers may be 30 to 170, preferably 65 to 150. Particularly, in the present invention, when the fineness of the polyethylene-based fiber is less than 300 deniers, the defective ratio may be increased by thinning the filaments when yarn is spun, and when the fineness of the fibers exceeds 600 deniers, . If the number of filaments of the yarn is less than 30, it may be disadvantageous to the laminating property. If the number of filaments is more than 170, the defective rate of yarn spinning may be increased.

In the present invention, the weaving of the fabric is not limited to a specific form, and both the plain weave type and the OPW (One Piece Woven) weave type are preferable. At this time, the fabric for the airbag has a warp density and weft density, that is, a weaving density in the warp direction and the weft direction of 36 to 65 bore / inch (th / inch), preferably 38 to 63 th / And may be 40 to 60 th / inch. The warp density and the weft density of the polyester fabric may be more than 36 th / inch respectively in terms of securing excellent mechanical properties of the airbag fabric, and the warp density and weft density of the fabric are preferably 65 th / inch or less.

In order to ensure airtightness at the fabric for airbags, the elongation is minimized by enduring the tensile force by high-pressure air or the like. At the same time, in order to ensure sufficient mechanical properties in the operation of the airbag, energy absorption performance is maximized at high- very important. Accordingly, the fabric can be made to have a cover factor of 1,750 to 2,500 as a raw material by the following equation (1), thereby improving the airtightness and energy absorption performance at the time of deploying the airbag.

[Equation 1]

When the cover factor of the fabric is less than 1,750, there is a problem that the air is easily discharged to the outside when the air is inflated. When the cover factor of the fabric is more than 2,500, when the airbag is installed, the retention and foldability of the airbag cushion It can fall.

The fabric for the airbag preferably further comprises a rubber component coating layer 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.

Particularly, the liquid silicone coating agent usable for the airbag fabric of the present invention may further include an adhesion promoter and a crosslinking agent for the purpose of enhancing the adhesion between the polyester fabric and the silicone agent, together with the viscosity control of the base silicone polymer have. At this time, the adhesion promoter may include about 0.2 to 8.0 parts by weight, preferably 0.5 to 7.5 parts by weight, relative to 100 parts by weight of the total coating agent, and the crosslinking agent component is about 0.2 to 8.0 parts by weight, preferably 0.5 To 7.5 parts by weight. As the adhesion promoter, 1,3,5-tris (trimethoxysilylpropyl) isocyanate or 3-glycidoxypropyltrimethoxysilane can be used, and as the crosslinking agent, there can be used at least two reactive silicon hydride functional groups Silicone cross-linking agents may be used. The liquid silicone coating agent may have a viscosity of 30,000 to 350,000 mPa 측정, preferably 35,000 to 330,000 mPa 측정, as measured at room temperature (25 캜).

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 fabric for an airbag of the present invention may have a tensile strength of 170 kgf / inch or more, or 170 to 350 kgf / inch, preferably 180 kgf / inch or more as measured by the method of American Society for Testing and Materials ASTM D 5034-GRAB . On the other hand, in order to absorb the inflator gas pressure at high temperature and high pressure during deployment of the air bag, a strong tensile strength is required. In order to satisfy this requirement, the tensile strength at room temperature of the fabric may preferably be 182 kgf / inch or more in terms of durability of the fabric, the tensile strength after aging (cycle, heat, humidity) may preferably be 158 kgf / inch or more.

Further, since the air bag fabric is rapidly expanded by high-temperature and high-pressure gas, an excellent tear strength level is required. The tear strength indicating the rupture strength of the fabric for the air bag is measured according to ASTM D 2261-TONGUE Or 15 kgf / inch or more, and preferably 20 kgf / inch or more when measured by the method of the present invention. Below 15 kgf / inch, airbag rupture may occur during deployment of the airbag, which can pose a significant risk to airbag function.

The airbag fabric of the present invention preferably has an air permeability of 0.5 to 5.0 cfm measured at a pressure difference of 125 Pa using the method of ASTM D 737 of the American Society for Testing and Materials. Particularly, when the air permeability is more than 5 cfm, it is not preferable in terms of maintaining the airtightness of the air bag.

The fabric for the airbag of the present invention is preferably 1.8 kgf or less or 0.3 to 1.8 kgf by using the American Society for Testing and Materials (ASTM D 4032) method. When the liner is more than 1.8 kgf, A problem occurs.

On the other hand, according to another embodiment of the invention, a method of manufacturing a fabric for airbags as described above is provided. The method of manufacturing a fabric for airbags according to the present invention comprises the steps of weaving a raw material for an airbag with a polyethylene yarn having a tensile strength of 10 g / d or more and a cutting elongation of 2% to 15%; Refining the raw paper for the woven airbag; And tentering the refined fabric.

In the present invention, the polyethylene-based raw material can be produced as a final airbag fabric through a conventional weaving method, refining and tentering processes. At this time, the weaving form of the fabric is not limited to a specific form, and both plain weave type and OPW (One Piece Woven) type weaving type are preferable.

In particular, the airbag fabric of the present invention can be manufactured by beaming, weaving, refining, and tentering processes using the polyester yarn as weft 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 >

However, since the present invention uses a high-strength linear polyethylene yarn, it is possible to perform a heat treatment process at a lower temperature than the conventional method. In the present invention, after the woven fabric is refined and tentered, the tentered fabric is coated with a rubber component and dried, and thereafter the vulcanization temperature is 110 to 150 ° C, preferably 115 to 145 ° C, more preferably 120 to 150 ° C, Curing at 140 < 0 > C. The vulcanization temperature may be 110 or more in terms of maintaining the mechanical properties such as tear strength of the fabric, and may be 150 DEG C or less in terms of ensuring improved lubrication of the fabric.

Particularly, the heat treatment process can be performed in a multistage manner. For example, the first heat treatment process is performed at 110 to 130 ° C, the second heat treatment process is performed at 130 to 140 ° C, A car heat treatment process can be performed. In the case where the fabric for airbags according to the present invention is produced through a low-temperature heat treatment process, by improving the material density and the like with low shrinkage characteristics of the high tenacity linear polyethylene yarn itself, excellent shape stability, air blocking effect, The toughness improving effect can be further increased.

 In addition, the curing time at the vulcanization temperature may be in the range of 30 to 120 seconds, preferably 35 to 100 seconds, and most preferably 40 to 90 seconds. When the curing time is less than 30 seconds, the curing of the coating layer by the rubber component is not effectively performed, and the mechanical properties of the fabric are lowered to peel off the coating, and when the curing time exceeds 120 seconds There is a problem that the degree of laminating and finishing of the final fabric is increased and the foldability is lowered.

The airbag fabric of the present invention can be coated on one side or both sides of the fabric with the rubber component as described above and the coating layer of the rubber component can be applied by a knife coat method, a doctor blade method, or a spray coating method However, this is also not limited to the above-mentioned method.

The coated airbag fabric can be manufactured in the form of an airbag cushion having a certain shape while being cut and sewed. The airbag is not limited to a particular type and can be manufactured in a general form.

On the other hand, according to another embodiment of the invention, a vehicle airbag comprising the above-described polyethylene fabric is provided. 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 classified into a frontal airbag, a side curtain airbag, and an external airbag. The frontal airbag includes a driver's seat, a passenger's seat, a side protection, a knee protection, an ankle protection, and a pedestrian protection airbag. The side curtain type airbag protects the passenger in the event of a side collision or an overturning accident. In addition, a pedestrian airbag and a bumper airbag protect the vehicle body and the pedestrian in the external airbag. Therefore, the airbag of the present invention includes both the frontal airbag, the side curtain airbag, and the external airbag.

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, by using a high tenacity polyethylene-based yarn, it is possible to provide an embossed fabric excellent in lubrication, foldability, energy absorbability and the like while being light in weight.

Particularly, the airbag fabric of the present invention is produced by weaving a fabric for an airbag using high-tenacity polyethylene yarn and fabricating the fabric, and if necessary, further processing such as coating amount of silicone or polyurethane as a coating material is minimized And excellent mechanical properties such as tensile strength and tear strength can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing one embodiment of a method for measuring the folding property of a fabric for airbags according to the present invention. Fig.

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 fineness of 350 denier, a number of filaments of 136, a tensile strength of 14 g / d, a cut elongation of 5%, a dry heat shrinkage of 5%, a specific gravity of 0.97 g / cm ³ , (PE) yarn was used to fabricate the fabric for the airbag through a rapier loom. At this time, in order to achieve the required air permeability, the weft yarns were woven in plain weave with the same number of warp yarns, and weaving density was 49 yarns / inch. Also, the weaving process was performed under the condition of an oblique tension of 230 cN.

The mixture was mixed with water so as to be 1.5 g / L of sodium hydroxide, 1.08 g / L of the surfactant, 1.08 g / L of the penetrating agent, and 1.25 g / L of the dispersant, and the mixture was divided into two chemical tanks and the temperature of each chemical tank was maintained at 75 캜 . In addition, two water baths each having a temperature of 80 캜 and 85 캜 were placed next to each chemical tank.

The raw paper for the airbag woven by the loom was firstly passed through the prepared chemical tank, then continuously passed through the two waterbaths, and then passed through the chemical tank and the two waterbaths.

The raw paper for the airbag which passed through the water washing tank was passed through a mangle and dehydrated, and then dried with hot air at 110 ° C to completely dry the residual moisture to prepare a fabric for an air bag.

Example 2

Using a yarn of Example 1, a fabric having a weaving density of 46 bands / inch was manufactured, and the fabric was knife-over-roll coated using a two-component liquid silicone rubber to obtain a coating amount of silicone rubber of 30 g / m < ^{2 &} gt ;.

Example 3

An airbag fabric was prepared in the same manner as in Example 1, except that a yarn having a fineness of 520 denier and a filament count of 136 was used and the weaving density was 41 yarns / inch.

Example 4

An airbag fabric was produced in the same manner as in Example 2, except that a linear polyethylene (PE) yarn having a fineness of 520 denier and a filament number of 136 was used and the weaving density was 41 bands / inch.

Comparative Example 1

A polyethylene (PE) yarn having a fineness of 350 denier, a number of filaments of 68, a tensile strength of 8 g / d, a cut elongation of 23%, a dry heat shrinkage of 12% and a number average molecular weight of 150,000 A fabric for an air bag was produced in the same manner as in Example 1. [

Comparative Example 2

Using the yarn of Comparative Example 1, a fabric having a weaving density of 46 yarns / inch was prepared, and the fabric was knife-over-roll coated using a two-liquid silicone rubber so that the coating amount of the silicone rubber was 30 g / m < ^{2 &} gt ;.

Comparative Example 3

The fabric for airbags was manufactured in the same manner as in Comparative Example 1, except that the yarn had the same yarn physical properties except that the fineness was 520 denier and the filament count was 68 in Comparative Example 1, and the weaving density was 41 yarns / inch. Respectively.

Comparative Example 4

Using the fabric of Comparative Example 3, a two-pack type liquid silicone rubber was knife-over-roll coated as in Comparative Example 2 to prepare an airbag coated fabric so that the coating amount of silicone rubber was 30 g / m ² .

Comparative Example 5

(PE) yarn having a fineness of 350 denier, a number of filaments of 68, a tensile strength of 9.5 g / d, a cutting elongation of 1.5%, a dry heat shrinkage of 15% and a number average molecular weight of 150,000 A fabric for an air bag was produced in the same manner as in Example 1. [

Comparative Example 6

A nylon 66 yarn (N66) having a fineness of 420 denier and a number of filaments of 68 was used, and a weaving density was set to 49 bands / inch. Specifically, the fabric was woven under the same conditions as in Example 1 at a warp tension of 230 cN using a loess loom.

Comparative Example 7

A polyester yarn (PET) having a fineness of 420 denier and a number of filaments of 68 was used, and a weaving density was set to 49 bands / inch. Specifically, the fabric was woven under the same conditions as in Example 1 at a warp tension of 230 cN using a loess loom.

The airbag fabrics of Examples 1 to 4 and Comparative Examples 1 to 7 were evaluated for physical properties as follows.

(a) Tensile strength: ASTM D 5034

The specimens were cut from the fabric for airbags and fixed to the lower clamp of a tensile strength measuring device according to American Society for Testing and Materials (ASTM) D 5034, and the strength of the airbag cushion specimen fracture was measured while moving the upper clamp upward.

(b) Tear Strength: American Society for Testing and Materials Standards (ASTM) D 2261

After the specimens were cut from the airbag fabric, they were cut 7 cm in the warp or oblique direction, and the left and right fabrics of the incision were attached to the grommet of the tear tester. The fabric was ruptured while crossing the clamps up and down while the fabric was mounted, and the strength was measured.

(c) Lecture: American Society for Testing and Materials Standards (ASTM) D 4032

A sample having a size of 100 mm x 200 mm is taken from the fabric for airbags and left for more than 24 hours at 20 ° C and 65% RH. Fold the prepared specimen in half, place it on the circular bend measuring plate, and press the measuring button to check the linguistic value displayed on the digital instrument.

(d) Folding performance

Two circular fabric 100 having a diameter of 721 mm were laser cut from the airbag fabric, and three circular fabric having a diameter of 200 mm made of the same fabric were laminated in the center of one circular fabric, and diameters of 152 mm, 165 mm, 178 mm, sewn by sewing with a sewing thread of Nylon 66 fiber of 1,260 denier in both the upper and lower sides, and a hole having a diameter of 70 mm was provided and used as an inflator insertion hole.

Further, a circular fabric having a diameter of 110 mm was placed at a position of 270 mm in the bias direction from the central portion to the bias direction, and the fabric was stuck on the fabric surface with a diameter of 85 mm by stitching with a sewing thread of nylon 66 fibers of 1,260 denier The sewing machine was sewed and a hole having a diameter of 25 mm was provided, and two vent holes were provided.

Subsequently, the outer periphery of the circular fabric was sewn on a circumference of 686 mm and 692 mm on the upper and lower sides with a 1,260 denier nylon 66 fiber sewing machine, sewed by double looping, and turned upside down to produce a 50 L capacity airbag.

The obtained air bag of 50 L capacity is folded in parallel to the biaxial directions of the AB and CD axes shown in Fig. First, as shown in Fig. 1, folding is made from the 270 mm line 5 toward the direction A from the original B direction, then folded from the folded fabric 200 mm toward the direction B from the line 6, Folds in the A direction from the 130 mm line from the further folded fabric. Fold the fabric on the other side in the same way so that it is symmetrical with the folded fabric.

Next, the airbag is folded in the direction D from the line 270 mm from the end in the direction C to the size 150 mm x 150 mm, then folding in the direction C from 105 mm, and folding in the direction C at 75 mm. Likewise, the fabric is folded in the same way from the other D-direction fabric so as to be symmetrical with the folded fabric. A load of 5 N was applied to the folded bag, and the thickness of the bag was measured at this time. Then, after removing the load, the thickness of the bag after one minute was measured.

The results of the above measurements for the airbag fabrics of Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1 below.

division The tensile strength
(kgf / inch) Phosphorus strength
(kgf / inch) Lecture
(kgf) Folding ability
(mm) Example 1 260 22 0.5 27 Example 2 255 38 0.7 29 Example 3 317 31 0.6 28 Example 4 309 54 0.8 30 Comparative Example 1 160 14 1.0 32 Comparative Example 2 158 26 1.1 31 Comparative Example 3 230 17 1.2 33 Comparative Example 4 218 30 1.4 35 Comparative Example 5 165 11 1.0 32

As shown in Table 1, in the case of the fabric properties for airbags manufactured using the high-strength linear polyethylene type yarn according to the present invention, the tensile strength and the tear strength related to the items for absorbing the inflator gas energy at high temperature and high pressure during the airbag deployment Is also suitable for cushioning for an air bag. In particular, it can be seen that the tensile strength and tear strength of the fabric for airbags of Examples 1 to 4 are excellent at 255 to 309 kgf / inch and 22 to 54 kgf, respectively. Further, the fabric for airbags according to Examples 1 to 4 exhibits excellent characteristics such as lubrication and folding properties of 0.5 to 0.8 kgf and 27 to 30 mm, respectively, which are related to airbag folding when the vehicle is housed. Particularly, as the fabric for airbags, the lower the value of the liner degree and the folding property is, the softer the fabric is, and there is an advantage in the manufacturing process of folding the cushion.

On the other hand, as shown in Table 1, it was confirmed that the airbag fabrics of Comparative Examples 1 to 5 using the conventional polyethylene yarn did not satisfy these characteristics. Particularly, the airbag fabric of Comparative Examples 1 to 5 has a very low tensile strength and tear strength relative to absorption of inflator gas energy at high temperature and high pressure in the airbag deployment of 158 to 230 kgf / inch and 11 to 30 kgf / inch, respectively, Actually, when the fabric is applied to the airbag, there is a danger of using the fabric because the fabric may be torn. In addition, the laminating and folding properties of Comparative Examples 1 to 5 were found to be high values of 1.0 to 1.4 kgf and 31 to 35 mm, respectively, and it was also found that the process efficiency of folding the airbag when storing the vehicle and the storage characteristics thereof were remarkably decreased.

On the other hand, the fabric for airbags of Example 1 and Comparative Examples 6 to 7 was evaluated in terms of the degree of lapping and the foldability by the method described above, and the weight was evaluated by the following method. Respectively.

(e) Fabric weight: ASTM D 3776

A sample having a size of 100 mm x 100 mm is taken from the fabric for airbags and left for more than 24 hours at 20 ° C and 65% RH. The prepared specimens were placed on an electronic balance and weighed to confirm the measurement.

division Yarn type Yarn fineness
(denier) Yarn
Number of filaments Weaving density
(B / inch) Lecture
(kgf) Folding ability
(mm) weight
(g) Example 1 PE 350 136 49 0.5 27 165 Comparative Example 6 N66 420 68 49 1.0 35 200 Comparative Example 7 PET 420 68 49 0.9 39 235

As shown in Table 2, the airbag fabric of Example 1 using the high-strength linear polyethylene yarn according to the present invention had a very low value of 0.5 kgf and 27 mm in the liner degree and the folding property, and the fabric was softened It can be seen that there is an advantage in the manufacturing process of folding the cushion. On the other hand, the airbag fabrics of Comparative Examples 6 to 7 using the conventional nylon 66 yarn and polyester yarn significantly increased in the degree of lapping and folding from 0.9 to 1.0 kgf and 35 to 39 mm, respectively, The efficiency can be lowered.

In addition, the fabric for the airbag of Example 1 has 165 g of the fabric weight, achieving a reduction in the overall weight of the vehicle, thereby remarkably improving vehicle fuel economy and the like. On the other hand, in Comparative Examples 6 and 7, the weights of the fabrics significantly increased to 200 g and 235 g, respectively, indicating that there was a limitation in weight reduction with conventional cushions made of nylon 66 yarn and polyester yarn have. In particular, the fabric for the airbag of Example 1 was reduced in weight by about 17% and 30%, respectively, compared to Comparative Examples 6 and 7 using conventional nylon 66 yarns and polyester yarns, so that the present invention is suitable for lightweight airbag fabrics .

On the other hand, an airbag cushion was manufactured using the fabric for airbags according to Examples 1 to 4 and Comparative Examples 1 to 5, and an airbag for DAB (driver airbag) cushion assembly vehicle was manufactured as shown in Table 2 below. The thus-completed vehicle airbag was subjected to a static expansion performance test (for example, an air conditioner at room temperature: 25 DEG C for 4 hours in an oven, hot: 85 DEG C for 4 hours in an oven, Cold: -30 DEG C for 4 hours in an oven) static test).

As a result of the above static test, it was evaluated as " Pass " in the case where no tearing, pinhole, or raw carbonization occurred, and the tearing, sewing pinhole, Failure "when any one of the occurrence or the raw carbonization occurred. If the result of the deployment test is "Pass", it can be used as a cushion for an airbag. If it is "Fail", it means that it can not be used as a cushion for an airbag.

The results of the static static performance test (static test) of the airbag cushions produced using the airbag fabric of Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 3 below.

division Cushion Specifications Abbreviation
Inflator
Pressure (kPa) Abbreviation
Inflator
Temperature (℃) Cold
Deployment test
(Static) Hot
Deployment test
(Static) Hot
Deployment test
(Limit) Example 1 DAB 200 350 Pass Pass Pass Example 2 DAB 200 350 Pass Pass Pass Example 3 DAB 200 350 Pass Pass Pass Example 4 DAB 200 350 Pass Pass Pass Comparative Example 1 DAB 200 350 Fail Fail Fail Comparative Example 2 DAB 200 350 Fail Fail Fail Comparative Example 3 DAB 200 350 Fail Fail Fail Comparative Example 4 DAB 200 350 Fail Fail Fail Comparative Example 5 DAB 200 350 Fail Fail Fail

As shown in Table 3, the airbags for vehicles including the fabric for airbags of Examples 1 to 4, to which the high tenacity polyethylene yarn was applied according to the present invention, were left in an oven under the heat treatment temperature condition and then subjected to a static test ) And the upper limit test were all performed. As a result, it was found that the tire had excellent performance as a vehicle airbag due to no tearing of fabric, occurrence of pin hole of sewing part, and carbonization of raw fabric .

In the case of the static test, the initial airbag cushion is designed and evaluated as the most basic deployment test. Only the module with the airbag cushion is evaluated, and the most normal temperature And deployment pressure. Quot; Pass " in the above-mentioned static static performance test (static test), it can be mass-produced as a cushion for an airbag.

On the other hand, the results of the static test of static airbags for automobile airbags including the fabric for airbags of Comparative Examples 1 to 5 showed that the airbag was broken when the airbag was deployed, the fabric was judged by fabric friction, ), Fabric judgment, fabric carbonization, etc., all cushions were evaluated as "Fail". As a result, it can be seen that the vehicle airbags including the fabric for airbags of Comparative Examples 1 to 5 are unusable as actual airbags. Particularly, in the development test for a driver airbag (cushion) assembly including a fabric of Comparative Examples 1, 2, and 5, a fabric tear occurred in the outer sewing portion and the tether portion of the cushion, In a deployment test for a driver airbag (DAB) cushion assembly that includes a tearing of the fabric at the inflator inlet and a seaming at the outer garment.

In the static tests for the airbags for automobiles including the fabrics of Comparative Examples 1 to 5, the tearing of the fabric tends to occur because the physical properties of the polyethylene yarn and the fabric itself are very low. pin hole generation, lack of friction resistance, and carbonization of the fabric. Therefore, the airbag fabric of Comparative Examples 1 to 5 may cause a great risk to the airbag function due to the airbag rupture or the like when it is applied to an actual airbag cushion for a vehicle. In addition, even if the airbag cushion performance is not satisfied even under the short heat treatment time conditions of room temperature, high temperature, and low temperature, if a car collision occurs while the fabric is stored for a long time at a high temperature, the safety of the passenger is not guaranteed at all .

Claims (15)

A polyethylene fabric for airbags comprising a polyethylene yarn having a tensile strength of 12 g / d or more, a cut elongation of 2 to 15%, a specific gravity of 0.99 g / cm ³ or less, and a dry heat shrinkage of 10% or less.
The method according to claim 1,
Wherein the polyethylene-based raw material comprises a repeating unit represented by the following formula (1).
[Chemical Formula 1]

The method according to claim 1,
Wherein the polyethylene-based raw material has a fineness of 300 denier to 600 denier and a filament count of 30 to 170.
delete The method according to claim 1,
The polyethylene-based raw material has a number average molecular weight of 200,000 or more.
The method according to claim 1,
Wherein the polyethylene-based raw yarn has a tensile strength of 14 g / d or more, a cut elongation of 3% to 10%, a specific gravity of 0.98 g / cm ³ or less, and a dry heat shrinkage ratio of 2.0% to 8.0%.
The method according to claim 1,
Wherein the fabric is coated with at least one rubber component selected from the group consisting of powdered silicone, liquid silicone, polyurethane, chloroprene rubber, neoprene rubber, and emulsion silicone resin. fabric.
8. The method of claim 7,
Wherein the coating amount of the rubber component per unit area is 20 g / m ² to 200 g / m ² .
The method according to claim 1,
Said fabric having a tensile strength of at least 170 kgf / inch as measured by the method of American Society for Testing and Materials ASTM D 5034-GRAB, polyethylene fabric for airbags.
The method according to claim 1,
The fabric is a polyethylene fabric for airbags having a tear strength of at least 15 kgf / inch as measured by the American Society for Testing and Materials ASTM D 2261-TONGUE.
The method according to claim 1,
Wherein the fabric has a lubrication of 1.8 kgf or less as measured by the method of ASTM D 4032 of the American Society for Testing and Materials.
Weaving the raw paper for an airbag with a polyethylene yarn having a tensile strength of 12 g / d or more, a cut elongation of 2% to 15%, a specific gravity of 0.99 g / cm ³ or less and a dry heat shrinkage of 10%
Refining the raw paper for the woven airbag, and
Tentering the refined fabric,
11. A method of producing a polyethylene fabric for an airbag according to any one of claims 1 to 3 and 5 to 11,
13. The method of claim 12,
Further comprising the step of curing the tentered fabric at a vulcanization temperature of 110 ° C to 150 ° C.
12. An airbag for a vehicle comprising a polyethylene fabric for an airbag according to any one of claims 1 to 3 and 5 to 11.
15. The method of claim 14,
Wherein the airbag is a frontal airbag, a side curtain airbag, or an external airbag.

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