KR102201865B1 - Air bag housing for automobile and manufacture method of thereof - Google Patents

Abstract

It relates to a vehicle airbag housing and a manufacturing method thereof, and more particularly, to a vehicle airbag housing including a hybrid fiber-reinforced composite and a method of manufacturing the vehicle airbag housing.

Description

Vehicle airbag housing and its manufacturing method {AIR BAG HOUSING FOR AUTOMOBILE AND MANUFACTURE METHOD OF THEREOF}

It relates to a vehicle airbag housing and a manufacturing method thereof, and more particularly, to a vehicle airbag housing including a hybrid fiber-reinforced composite and a method of manufacturing the vehicle airbag housing.

In recent years, the automobile industry is striving to improve automobile fuel economy in line with the global trend of reducing carbon dioxide emissions. As a result, automotive lightweight design has been proposed as one solution, and automotive parts are widely used as plastic parts instead of steel.In particular, polypropylene, which is characterized by low specific gravity, excellent moldability, heat resistance, and chemical resistance, is already used as a bumper, It is widely used as a material such as instrument panel.

In the case of the airbag housing, impact resistance against high pressure and the like is required when the airbag is deployed. Existing airbag housings are mainly made of steel, and in this case, they are heavier than other materials, and there is a risk of a bell mouth defect that opens when the airbag is deployed. In addition, as the passenger airbag cushion size increases, the inflator pressure and the airbag housing size need to be increased. Accordingly, there is a demand for lighter weight and strength/stiffness improvement of the airbag housing.

Recently, as a result of various research and development, a polypropylene-based composite material having excellent rigidity and low-temperature impact strength has been introduced. Japanese Patent Publication No. 2006-257259 (2006.09.28) discloses a material having excellent low-temperature impact performance including propylene-based resin and talc, but there is a problem in that long-term durability and impact resistance are insufficient.

In addition, in the case of injection by inserting a steel material, since it is manufactured by separately preparing a steel material as an insert and additionally injection molding, it has a disadvantage that the cost is increased and the effect of weight reduction is insufficient.

An object of the present invention is to provide an airbag housing for a vehicle that can secure excellent strength and rigidity, and at the same time achieve sufficient weight reduction and cost reduction.

In one embodiment of the present invention, it is manufactured by press molding a hybrid fiber reinforced composite material including a continuous fiber reinforced composite material (CFT) and a long fiber reinforced composite material (LFT), and the following Equations 1 to 2 It is possible to provide an airbag housing for a vehicle, characterized in that satisfactory.

0.3 ≤ G _L /G _C ≤ 1.0 [Equation 1]

400 ≤ specific flexural strength ≤ 800 [Equation 2]

(In Equation 1 above, G _L / G _C is the ratio of the continuous fiber reinforced composite material (CFT) to the long fiber reinforced composite material (LFT), and the content of the fiber contained in the long fiber reinforced composite material (LFT) It is the value divided by the content of fiber contained in the composite material (CFT),

In Equation 2, the specific flexural strength is the specific flexural strength (MPa) measured according to ISO 178 standards.)

In another embodiment of the present invention, (a) preheating a continuous fiber reinforced composite material (CFT) and a long fiber reinforced composite material (LFT); (b) placing a continuous fiber-reinforced composite material (CFT) on the lower mold and placing a long fiber-reinforced composite material (LFT) on the continuous fiber-reinforced composite material (CFT); (c) placing an upper mold on the long fiber reinforced composite material (LFT) and pressurizing to press molding; And (d) trimming/piercing after press-forming; it can provide a method of manufacturing an airbag housing for a vehicle including.

The vehicle airbag housing has excellent strength and stiffness, as well as improved shock absorption performance and weight reduction characteristics. Accordingly, it can be used for various fields other than the vehicle airbag housing which requires high strength, stiffness, shock absorption performance, and weight reduction characteristics.

Through the manufacturing method of the vehicle airbag housing, it is possible to manufacture an airbag housing for a vehicle with improved process efficiency, excellent strength and rigidity, and improved shock absorption performance and weight reduction characteristics.

1 is a flow chart showing a method of manufacturing an airbag housing for a vehicle according to an embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments to be described later. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, However, these embodiments are provided to complete the disclosure of the present invention, and to fully inform the scope of the invention to those of ordinary skill in the art to which the present invention pertains, and the present invention is defined by the scope of the claims. It just becomes. The same reference numerals refer to the same elements throughout the specification.

In one embodiment, the vehicle airbag housing according to the present invention may be manufactured by press molding a hybrid fiber reinforced composite material including a continuous fiber reinforced composite material (CFT) and a long fiber reinforced composite material (LFT).

The hybrid fiber reinforced composite material may have a structure in which the continuous fiber reinforced composite material (CFT) and long fiber reinforced composite material (LFT) are stacked, and more preferably, a long fiber on the upper surface of the continuous fiber reinforced composite material (CFT). A structure in which a reinforced composite material (LFT) is laminated is effective because it can simultaneously impart high impact absorption performance and interfacial bonding strength, along with excellent strength and rigidity.

Hereinafter, a continuous fiber reinforced composite material (CFT) and a long fiber reinforced composite material (LFT) will be described in detail.

The continuous fiber-reinforced composite material (CFT) according to the present invention may be a composite material including continuous fibers in a propylene-based resin as a thermoplastic resin.

The propylene-based resin may include polypropylene alone or a resin in which polypropylene and other types of monomers are copolymerized. For example, polypropylene homopolymerized resin, propylene-ethylene copolymer resin, propylene-butene copolymer resin, ethylene-propylene -It may contain one selected from the group consisting of butene copolymer resins and combinations thereof. By employing the propylene-based resin, the continuous fiber reinforced composite material (CFT) may be advantageous in improving the strength and shock absorption characteristics for cost.

The continuous fiber is included in order to improve the strength and rigidity of the vehicle airbag housing and implement light weight characteristics, and the continuous fiber may include one selected from the group consisting of glass fiber, carbon fiber, and combinations thereof.

Specifically, the continuous fiber is one fiber reinforcement material selected from the group consisting of glass fiber, carbon fiber, and combinations thereof, and the form included in the continuous fiber reinforced composite material (CFT) is included in the form of continuous fiber.

In this case, the continuous fiber means that it exists in a continuous form without being broken inside, depending on the final size of the vehicle airbag housing manufactured from the continuous fiber reinforced composite material (CFT). For example, like a continuous fiber in a UD sheet (unidirection sheet), the continuous fiber can be produced in a continuous process, and by continuously supplying the continuous fiber to this continuous process, a continuous fiber reinforced composite material including continuous fibers (CFT) can be produced.

Accordingly, the continuous fiber-reinforced composite material (CFT) may be manufactured into a product having a specific shape such as a sheet, and in such a product, the continuous fiber has a length of a specific range depending on the shape of the product. However, since the length of this specific range can be arbitrarily adjusted in the manufacturing process in which the continuous fiber is continuously supplied, the continuous fiber should be considered to have'continuity', and most of the continuous fibers such as UD sheet or continuous fiber In case, it does not break inside the product and has continuity.

In one embodiment, the continuous fiber-reinforced composite material (CFT) may include continuous fibers such that the continuous fibers have a single orientation, such as a UD sheet.

In this case, the continuous fiber may have a single orientation within the continuous fiber reinforced composite material (CFT). The continuous fiber is advantageous in securing excellent strength and stiffness by having a single orientation in the continuous fiber reinforced composite material (CFT), and is suitably mixed with a polypropylene resin in the continuous fiber reinforced composite material (CFT), It may be more advantageous to improve the shock absorption performance of the continuous fiber reinforced composite material (CFT).

In one embodiment, the continuous fiber-reinforced composite material (CFT) may include 40 to 60% by weight of the propylene-based resin and 40 to 60% by weight of the continuous fiber. More preferably, it may contain 40 to 50% by weight of the propylene-based resin and 50 to 60% by weight of continuous fibers.

When the continuous fiber is contained within the above range, it is difficult to secure the strength and stiffness required in the vehicle airbag housing, and when it exceeds the above range, the polypropylene resin is not sufficiently impregnated and thus continuous fiber reinforced composite material (CFT) In addition, the manufacturing of the vehicle airbag housing itself may cause a problem that is impossible.

The cross-section of the continuous fiber may have an average diameter of about 15 μm to about 20 μm, for example, about 16 μm to about 19 μm. By maintaining the average diameter of the continuous fiber in the above range, excellent strength and stiffness can be realized even in the content of the above range, and the continuous fiber reinforced composite material (CFT) manufactured therefrom can exhibit appropriate thickness and physical properties.

The continuous fiber-reinforced composite material (CFT) may be formed by laminating 3 to 10 continuous fiber-reinforced composite material sheets by thermocompression, and more preferably, 4 to 8 sheets are stacked.

The lamination of the continuous fiber-reinforced composite material sheet may be formed by laminating at least one or more angles selected from 0 to 90 degrees (°). For example, when three sheets are stacked, they can be stacked to cross each other at 0°/90°/0°, and when stacking 9 sheets, 0°/45°/90°/45°/0°/45°/90° /45 degrees / 0 degrees can be stacked to intersect Seogyo, but is not limited thereto.

The long fiber-reinforced composite material (LFT) according to the present invention may be a composite material including long fibers in a propylene-based resin as a thermoplastic resin. The propylene-based resin is the same as the propylene-based resin, which is a thermoplastic resin included in the continuous fiber-reinforced composite material (CFT), and is effective in improving the interfacial bonding strength between the continuous fiber-reinforced composite material (CFT) and the long fiber-reinforced composite material (LFT). .

The long fiber is a fiber material having an average length of about 50 mm or less, more preferably 1 mm or more and 50 mm or less, and may mean one fiber reinforcement material selected from the group consisting of glass fiber, carbon fiber, and combinations thereof.

In one embodiment, the long fiber-reinforced composite material (LFT) may include 60 to 75% by weight of the propylene-based resin and 25 to 40% by weight of the long fiber. More preferably, it may contain 65 to 70% by weight of the propylene resin and 30 to 35% by weight of long fibers.

When the filament is contained in less than the above range, it is difficult to secure the strength and rigidity required by the vehicle airbag housing, and when it exceeds the above range, dispersion is non-uniform, and moldability may be deteriorated.

In one embodiment, it is preferable that the vehicle airbag housing according to the present invention satisfies the following Equations 1 to 2.

0.3 ≤ G _L /G _C ≤ 1.0 [Equation 1]

400 ≤ specific flexural strength ≤ 800 [Equation 2]

(In Equation 1 above, G _L / G _C is the ratio of the continuous fiber reinforced composite material (CFT) to the long fiber reinforced composite material (LFT), and the content of the fiber contained in the long fiber reinforced composite material (LFT) It is the value divided by the content of fiber contained in the composite material (CFT),

In Equation 2, the specific flexural strength is the specific flexural strength (MPa) measured according to ISO 178 standards.)

More preferably, it is preferable that the vehicle airbag housing satisfies the following Equations 3 to 4.

0.5 ≤ G _L /G _C ≤ 0.7 [Equation 3]

40 ≤ G _L +G _C ≤ 60 [Equation 4]

(In Equation 3 above, G _L / G _C is the ratio of the continuous fiber reinforced composite material (CFT) to the long fiber reinforced composite material (LFT), and the content of fibers contained in the long fiber reinforced composite material (LFT) It is the value divided by the content of fiber contained in the composite material (CFT),

Equation 4 is the total fiber content (% by weight) included in the vehicle airbag housing of the present invention.)

By controlling the content of the continuous fiber reinforced composite material (CFT) and the long fiber reinforced composite material (LFT) fiber reinforcement within the above-described range, it is possible to more effectively impart excellent strength and rigidity. In particular, since it is possible to implement excellent interfacial bonding strength only by press molding, there is an advantage of achieving excellent specific flexural strength as shown in Equation 2 above.

The specific flexural strength is a value obtained by dividing the value of applying a force from the top to the center of the specimen by the strain generated in the specimen, and can be measured by the ISO 178 method. That is, the vehicle airbag housing can have an improved resistance value to withstand bending, and has excellent strength and stiffness, and has excellent bonding strength between a continuous fiber reinforced composite material (CFT) and a long fiber reinforced composite material (LFT). Able to know.

The vehicle airbag housing of the present invention is manufactured by press molding a hybrid fiber reinforced composite material including the aforementioned continuous fiber reinforced composite material (CFT) and long fiber reinforced composite material (LFT), and has excellent strength and stiffness. Together, there is an advantage that can exhibit high impact absorption performance and improved interfacial bonding.

In addition, the impact strength of the vehicle airbag housing may range from about 22 J/mm to about 50 J/mm. More specifically, it may be about 22 J/mm to about 40 J/mm. The'Falling Ball Impact Strength' represents the resistance force that an arbitrary object withstands an instantaneous concentrated external force, and is the'surface impact' intensity measured further away from the surface of the object, which can be measured by the falling ball impact measurement method according to ISO 6603. have. When the impact strength of the falling ball is less than the above range, sufficient impact performance is not secured and durability is deteriorated when the airbag is deployed, so that it is difficult to apply to parts requiring excellent impact performance, such as an airbag housing for a vehicle.

In addition, the non-flexural stiffness (= specific flexural modulus) of the vehicle airbag housing may be about 17 GPa to about 30 GPa, and specifically, about 17 GPa to about 20 GPa. The specific flexural stiffness (= specific flexural modulus) is a measure of how much a material can bend without permanent deformation and fracture, and can be measured by the ISO 178 method.

The vehicle airbag housing has a structure in which a long fiber-reinforced composite material (LFT) is laminated on an upper portion of a continuous fiber-reinforced composite material (CFT), and the non-flexural stiffness (= non-flexural modulus) of the above by including a fiber composite material in a specific amount. Can keep. That is, the vehicle airbag housing may have excellent strength and rigidity.

Another embodiment of the present invention is (a) preheating a continuous fiber reinforced composite material (CFT) and a long fiber reinforced composite material (LFT) (S10);

(b) placing a continuous fiber-reinforced composite material (CFT) on the lower mold and placing a long fiber-reinforced composite material (LFT) on the continuous fiber-reinforced composite material (CFT) (S20);

(c) placing an upper mold on the long fiber-reinforced composite material (LFT) and pressurizing to press molding (S30); And

It is possible to provide a method of manufacturing an airbag housing for a vehicle including (d) trimming/piercing after press molding (S40).

Through the manufacturing method of the vehicle airbag housing, a vehicle airbag housing may be manufactured using a hybrid fiber reinforced composite material including a continuous fiber reinforced composite material (CFT) and a long fiber reinforced composite material (LFT). More specifically, it is a structure in which a long fiber reinforced composite material (LFT) is laminated on top of a continuous fiber reinforced composite material (CFT), and by press molding a hybrid fiber reinforced composite material containing the total fiber content in a specific range, it has excellent strength and stiffness. In addition, the interfacial bonding strength is improved, and the manufacturing process is simplified, thereby reducing cost.

1 is a flow chart showing a method of manufacturing an airbag housing for a vehicle according to an embodiment of the present invention. 1, step (a) is a step (S10) of preheating the continuous fiber reinforced composite material (CFT) and the long fiber reinforced composite material (LFT) to a specific temperature range.

The preheating temperature is preferably 200 to 250°C, and more preferably 220 to 240°C is effective for improving processability and interfacial bonding between the continuous fiber reinforced composite material (CFT) and the long fiber reinforced composite material (LFT).

In the step (b), a continuous fiber reinforced composite material (CFT) is first mounted on a lower mold, and a long fiber reinforced composite material (LFT) is placed on the lower mold (S20). It is preferable to have a structure in which a long fiber reinforced composite material (LFT) is laminated on the upper surface of the continuous fiber reinforced composite material (CFT) in order to improve the durability, strength and rigidity of the vehicle airbag housing through press molding. .

The step (c) is a step (S30) of placing an upper mold on the long fiber reinforced composite material (LFT) and pressurizing it to perform press molding (S30).

In steps (b) and (c), the temperature of the upper mold and the lower mold is preferably 60 to 80°C, and more preferably 60 to 75°C is effective because the surface of the vehicle airbag housing is uniformly formed.

The pressure applied in step (c) is 300 to 600 tons (TON), and the pressing time is preferably 40 to 100 seconds (sec). When the applied pressure and the pressing time are within the above ranges, the interfacial bonding strength between the continuous fiber reinforced composite material (CFT) and the long fiber reinforced composite material (LFT) is improved, so that the strength and stiffness are excellent, and the weight reduction characteristics can be improved.

When the applied pressure is less than 300 tons (TON) or the pressing time is less than 40 seconds (sec), the interfacial bonding strength between the continuous fiber reinforced composite material (CFT) and the long fiber reinforced composite material (LFT) is lowered, resulting in a decrease in specific flexural strength and There is a possibility that mechanical properties such as non-bending stiffness may be deteriorated, and when the applied pressure exceeds 600 tons (TON) or the pressing time exceeds 100 seconds (sec), continuous fiber reinforced composite material (CFT) and long fibers Internal and external cracks may occur due to deterioration of the reinforced composite material (LFT), and at this time, a problem of lowering strength and rigidity may occur.

The step (d) is a step (S40) of trimming/piercing after press molding. After the vehicle airbag housing is removed from the mold, the burr generated in the vehicle airbag housing can be removed through a separate trimming/piercing mold.

The vehicle airbag housing manufactured through the manufacturing method of the vehicle airbag housing secures high process efficiency by simple press molding, has excellent strength and stiffness, and improves shock absorption performance and weight reduction characteristics. It can be used as a variety of products that require high rigidity and lightweight properties.

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are merely for illustrating or explaining the present invention in detail, and the present invention is not limited thereto.

< Manufacturing example >

Manufacturing example One: Long fibers Reinforced composite material ( LFT )

After arranging 30% by weight of glass fiber (OCV company, SE4849) having an average diameter of 17.5㎛ and an average length of 25mm to have a single orientation, it was impregnated with 70% by weight of polypropylene resin and thermally compressed at 230°C to obtain an average thickness. A 3.5mm long fiber reinforced composite material (LFT) was prepared.

Manufacturing example 2: Continuous fiber reinforced composite material ( CFT )

After arranging 60% by weight of continuous glass fibers (OCV, SE4849) having an average diameter of 17.5㎛ to have a single orientation, impregnating 40% by weight of polypropylene resin and impregnating at 230℃ to reinforce continuous fibers with an average thickness of 0.3mm A composite material (CFT) sheet was prepared.

< Example And Comparative example >

Example One : LFT / CFT

Six sheets of continuous fiber-reinforced composite material (CFT) prepared in Preparation Example 2 were stacked by thermal compression by crossing at 90 degrees / 0 degrees / 90 degrees / 90 degrees / 0 degrees / 90 degrees, and then the top of the lower mold at 70 °C Then, the long fiber reinforced composite material (LFT) prepared in Preparation Example 1 is placed to form a structure in which the long fiber reinforced composite material (LFT) is laminated on the top of the continuous fiber reinforced composite material (CFT). Then, the upper mold at 70°C is placed and press molding is performed for 60 seconds (sec) with a pressing force of 400 tons (TON). After the molding was finished, the mold was demolded from the mold, and then the burr was removed using a separate trimming/piercing mold to prepare a vehicle airbag housing with a total content of 50% by weight of continuous fibers and long fibers in the vehicle airbag housing, and the following evaluation method According to the measurement of the physical properties are shown in Table 2.

Example 2 : CFT / LFT / CFT

As shown in Table 1 below, 6 sheets of continuous fiber-reinforced composite material (CFT) prepared in Preparation Example 2 were stacked by thermal compression bonding by crossing 90 degrees / 0 degrees / 90 degrees / 90 degrees / 0 degrees / 90 degrees. Then, after seating on the top of the lower mold at 70°C, the long fiber reinforced composite material (LFT) prepared in Preparation Example 1 was placed, and the continuous fiber reinforced composite material (CFT) sheet prepared in Preparation Example 2 again on the upper part 6 In the same manner as in Example 1, except for forming a structure in which the LFT and the CFT are sequentially positioned on the top of the CFT by thermal compression bonding and stacking the sheets at 90 degrees / 0 degrees / 90 degrees / 90 degrees / 0 degrees / 90 degrees. A vehicle airbag housing was manufactured, and a vehicle airbag housing having a total content of 50% by weight of continuous fibers and long fibers in the vehicle airbag housing was manufactured, and physical properties were measured according to the following evaluation method, and are shown in Table 2.

Comparative example One

The long fiber reinforced composite material (LFT) prepared in Preparation Example 1 was placed on the top of the lower mold at 70°C, and the upper mold at 70°C was placed, and then for 100 seconds (sec) with a pressing force of 400 tons (TON). Press molding. After the molding was completed, the mold was demolded from the mold, and then the burr was removed using a separate trimming/piercing mold to manufacture an airbag housing for a vehicle with a total content of long fibers of 40% by weight in the airbag housing for a vehicle, and physical properties according to the following evaluation method. Was measured and shown in Table 2.

Comparative example 2

Place 13 sheets of continuous fiber-reinforced composite material (CFT) prepared in Preparation Example 2 at the top of the lower mold at 70°C by crossing them at 0° and 90°, placing the upper mold at 70°C, and then 400 tons (TON) Press molding for 60 seconds (sec) with a pressing force of After the molding was completed, the mold was demolded from the mold, and then the burr was removed using a separate trimming/piercing mold to manufacture an airbag housing for a vehicle with a total content of long fibers of 50% by weight in the airbag housing for a vehicle, according to the following evaluation method. Was measured and shown in Table 2.

Comparative example 3

The long fiber-reinforced composite material (LFT) prepared in Preparation Example 1 was placed on the top of the lower mold at 70°C, and then 6 sheets of the continuous fiber-reinforced composite material (CFT) prepared in Preparation Example 2 were placed on the top of the long-fiber-reinforced composite material (LFT) at 90°/ By intersecting at 0°/90°/90°/0°/90°, it is laminated and positioned to form a structure in which continuous fiber reinforced composite material (CFT) is laminated on top of long fiber reinforced composite material (LTF). Next, the upper mold at 70°C is placed and press molding is performed for 60 seconds (sec) with a pressing force of 400 tons (TON). After the molding was finished, the mold was demolded from the mold, and then the burr was removed using a separate trimming/piercing mold to prepare a vehicle airbag housing with a total content of 50% by weight of continuous fibers and long fibers in the vehicle airbag housing, and the following evaluation method According to the physical properties were measured and shown in Table 2.

<Evaluation>

The physical properties of the vehicle airbag housing were evaluated according to the experimental examples described later.

Experimental example One: Tensile strength And stiffness measurement

The fiber-reinforced composites according to the Examples and Comparative Examples were measured for non-tensile strength and non-tensile stiffness according to ISO 527, and the results are shown in Table 2 below.

Experimental example 2: Specific flexural strength And Of specific flexural modulus Measure

The specific flexural strength and rigidity of the vehicle airbag housing were measured according to ISO 178, and the results are shown in Table 2 below.

Experimental example 3: Measurement of impact strength of falling ball

The falling ball impact strength was measured according to the method for measuring the falling ball impact strength (ISO 6603) for the vehicle airbag housing, and the results are shown in Table 2 below.

[Table 1]

[Table 2]

As shown in Table 2, Example 1 shows that by placing a long fiber-reinforced composite material (LFT) on the continuous fiber-reinforced composite material (CFT), the flexural characteristics and the impact strength of falling balls are significantly improved compared to the comparative examples. Able to know. In the case of Example 2, it was found that the mechanical properties were increased, but the moldability was slightly decreased.

Claims (15)

It is manufactured by press molding a hybrid fiber reinforced composite material including continuous fiber reinforced composite material (CFT) and long fiber reinforced composite material (LFT),
The hybrid fiber reinforced composite material has a structure in which a long fiber reinforced composite material (LFT) is laminated on an upper surface of the continuous fiber reinforced composite material (CFT),
The continuous fiber reinforced composite material (CFT) contains 40 to 60% by weight of a propylene-based resin and 40 to 60% by weight of continuous fibers,
The long fiber reinforced composite material (LFT) contains 60 to 75% by weight of a propylene-based resin and 25 to 40% by weight of a long fiber,
The cross-section of the continuous fiber has an average diameter of 16 μm to 19 μm,
The continuous fiber-reinforced composite material (CFT) is formed by laminating 6 to 8 continuous fiber-reinforced composite material sheets by thermal compression,
The stacking is formed by stacking at least one angle selected from 0 to 90 degrees (°),
The specific flexural stiffness measured according to the ISO 178 standard is 17.3 GPa to 18.6 GPa,
Falling ball impact strength measured according to ISO 6603 standard is 22.1 J/mm to 23.8 J/mm,
An airbag housing for a vehicle, characterized in that satisfying the following Equations 1 to 2.
0.3 ≤ G _L /G _C ≤ 1.0 [Equation 1]
436 ≤ specific flexural strength ≤ 800 [Equation 2]
(In Equation 1 above, G _L / G _C is the ratio of the continuous fiber reinforced composite material (CFT) to the long fiber reinforced composite material (LFT), and the content of the fiber contained in the long fiber reinforced composite material (LFT) It is the value divided by the content of fiber contained in the composite material (CFT),
In Equation 2, the specific flexural strength is the specific flexural strength (MPa) measured according to ISO 178 standards.)
delete The method of claim 1,
Each of the continuous fibers and long fibers includes one fiber selected from the group consisting of glass fibers, carbon fibers, and combinations thereof.
The method of claim 1,
The propylene-based resin comprises one selected from the group consisting of polypropylene homopolymerized resin, propylene-ethylene copolymer resin, propylene-butene copolymer resin, ethylene-propylene-butene copolymer resin, and combinations thereof.
The method of claim 1,
The vehicle airbag housing satisfies Equations 3 to 4 below.
0.5 ≤ G _L /G _C ≤ 0.7 [Equation 3]
40 ≤ G _L +G _C ≤ 60 [Equation 4]
(In Equation 3 above, G _L / G _C is the ratio of the continuous fiber reinforced composite material (CFT) to the long fiber reinforced composite material (LFT), and the content of fibers contained in the long fiber reinforced composite material (LFT) It is the value divided by the content of fiber contained in the composite material (CFT),
Equation 4 is the total fiber content (% by weight) included in the vehicle airbag housing of the present invention.)
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