KR101732488B1 - Impact-resistant flexible composite using shear-thickening fluid and shape-variable protection apparatus - Google Patents

Abstract

 The disclosed impact resistant flexible composites include a shear-thickening fabric layer comprising a fabric impregnated with a reflective layer and a shear-thickening fluid. The impact resistant flexible composite can provide excellent flexibility and impact resistance.

Description

TECHNICAL FIELD [0001] The present invention relates to an impact-resistant flexible composite using a shear thickening fluid and a shape variable protective device using the same. [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective material and a protective device, and more particularly, to a shockproof flexible composite which can be used in an outer space and a shape variable protective device using the same.

Space debris are objects that float in space and are called space junk. The space debris may be debris generated due to collision or an artificial impact between the satellite and the satellite left in space when the operation is suspended or terminated, paint painted on the outer wall of the projectile, fine fuel particles discharged from the engine of the satellite And astronauts can be various tools lost while performing work in space.

These cosmic debris, which are small in size, travel around the Earth at very high speeds, so colliding with space structures (such as satellites) can cause serious damage to the structure. For example, if a 1-kilogram space debris floats in space at 10 km / s and collides with a 1,000-kilogram mass of satellites, the satellite will have enough destructive power to be completely destroyed. The number of these universe fragments is not only large, but also increasing rapidly.

Therefore, it is necessary to develop high-performance protective materials and protective devices for the protection of space structures and astronauts.

The technical object of the present invention is to provide a shockproof flexible composite using shear thickening fluid.

Another object of the present invention is to provide a variable protective device using the composite.

An impact-resistant flexible composite according to an embodiment for realizing the objects of the present invention includes a shear-thickening fabric including a fabric impregnated with a reflective layer and a shear-thickening fluid.

In one embodiment, the reflection layer may include a polymer film combined with a metal thin film.

In one embodiment, the shear thickening fluid may comprise silica or aluminum nanoparticles dispersed in a nonvolatile dispersion medium.

In one embodiment, the fabric of the shear thickened fabric layer is selected from the group consisting of aramid fibers, polyethylene fibers, polypropylene fibers, Zylon fibers, nylon fibers, glass fibers, carbon fibers, ultra high molecular weight polyethylene Ultra-High Molecular Weight Polyethylene) fiber and PBO (p-phenylene-2,6-benzobisoxazole) fiber.

In one embodiment, in the shear thickened fabric layer, the shear thickening fluid content may be from 60 wt% to 80 wt%.

In one embodiment, the shear-thickening fabric layer may further comprise a radiation non-transmissive filler comprising a salt of barium, iodine, bismuth, uranium or zirconium.

In one embodiment, the impact resistant flexible composite further comprises an antistatic layer having electrical conductivity and a strength enhancing layer comprising a fabric, wherein the reflective layer is located at an outermost position.

In one embodiment, the antistatic layer may comprise at least one selected from the group consisting of a metal-coated fiber assembly, a metal-coated fabric, a metal-coated polymer film, and a conductive carbon structure.

In one embodiment, the fabric of the strength-enhancing layer may be coated with a synthetic rubber.

In one embodiment, the reflective layer, the sheathed-thickened fabric layer, the antistatic layer, and the strength-enhancing layer may be laminated with free boundary conditions.

The shape variable protective device according to an embodiment for realizing the object of the present invention includes a protective sheet and a shape memory alloy supporting part combined with the protective sheet and capable of expanding or collapsing the protective sheet according to a change in temperature . The protective sheet comprises a shear thickened fabric layer comprising a fabric impregnated with a reflective layer and a shear thickening fluid.

In one embodiment, the shape memory alloy support portion includes a central support portion in a cross shape, a first support portion extending in a first direction and coupled to the center support portion, and a second support portion extending in a second direction perpendicular to the first direction, And a second support portion coupled to the center support portion and not fixed to the first support portion.

In one embodiment, the first support or the second support may be bent in a zigzag shape at a specific temperature.

In one embodiment, the shape memory alloy supporter may include at least one of a radial main support portion and a branch of the main support portion, and a sub support portion having a width smaller than that of the main support portion.

In one embodiment, the shape memory alloy support may comprise at least one selected from the group consisting of a copper-zinc-aluminum alloy, a copper-aluminum-nickel alloy, a nickel-titanium alloy and a nickel-titanium-hafnium alloy.

According to the present invention, the impact-resistant flexible composite is highly utilizable by using a flexible material such as a fabric or a polymer film as a whole. For example, when not in use, it is easy to fold and store, and can be provided in various forms. Therefore, various applications as an impact resistant material are possible.

In addition, the impact resistant flexible composite provides high impact resistance in comparison with small volume and weight using a shear thickening fluid.

In addition, the impact-resistant flexible composite has a reflective function, an antistatic function, an electromagnetic wave shielding function, and the like, thereby providing excellent heat insulation performance in a harsh environment such as an outer space, Can be protected.

In addition, the protection device according to the present invention can change the shape of the protection device by using the flexible protection sheet and the shape memory alloy support unit coupled thereto. The protective device can expand or collapse the protective sheet without a separate actuator. Therefore, it can be usefully used in an outer space or the like.

1 is a cross-sectional view illustrating an impact resistant flexible composite according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a configuration variable protective device according to an embodiment of the present invention. FIG.
3 is a cross-sectional view of the protective device of Fig.
4 is a plan view showing a variable protective device according to another embodiment of the present invention.
5 is a view schematically showing an example of use of the variable protective device of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are enlarged to illustrate the present invention in order to clarify the present invention. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Shock resistant flexible composite

1 is a cross-sectional view illustrating an impact resistant flexible composite according to an embodiment of the present invention.

Referring to FIG. 1, the impact resistant flexible composite includes a reflective layer 10, a shear thickened fabric layer 20, an antistatic layer 30, and a strength reinforcing layer 40.

The reflective layer 10 may block sunlight and solar radiation in space. Space is an extreme temperature environment. For example, it is about 120 ° C when sunlight shines, and reaches -100 ° C when sunlight does not shine (for example, when it is covered by earth shadows or the like). The reflective layer 10 reflects sunlight and solar radiation to perform an insulation function.

The reflective layer 10 may include a metal having a high reflectivity, for example, aluminum, silver, or the like. In addition, the reflective layer 10 may include a polymer film or fabric to have flexibility. For example, the reflective layer 10 may include a polymer film combined with a metal thin film.

For example, the reflective layer 10 may comprise a polyethylene terephthalate (PET) film combined with an aluminum foil. Preferably, a biaxially oriented PET film can be used. The polyethylene terephthalate film is excellent in electrical insulation, tensile strength, chemical stability, gas barrier properties, and is suitable as a base film of a reflective member.

In another embodiment, as the reflective material, a white pigment or the like may be used in place of the metal. The white pigment may include titanium oxide or the like. For example, a fabric formed of fibers comprising a white pigment may be used as the reflective layer 10.

The reflective layer 10 may have a multi-layer structure having the same structure or different structures. For example, the reflective layer 10 may have a multilayer structure in which a polyethylene terephthalate film bonded with an aluminum thin film is repeatedly laminated, and preferably, a plurality of sheets are laminated so that the effective radiation degree is close to zero.

For example, the reflective layer 10 may have a thickness of 10 to 400 um, but is not limited thereto.

The sheathed thickened fabric layer 20 comprises a fabric impregnated with a shear-thickening fluid. The shear thickening fluid has a degree of flexibility to ensure sufficient activity because it exists in a liquid state in the absence of an external stimulus, but has a characteristic that when the external shear stimulus is applied, the stiffness instantaneously changes and solidifies. This is a reversible reaction that is completely restored when the external force is removed. The shear thickening fluid has a colloidal state comprising nanoparticles. When an impact is applied to the shear-thickening fluid, the nanoparticles closely contact each other to form a hydrocluster, resulting in instantaneous solidification.

The fabric may be selected from the group consisting of aramid, polyethylene, polypropylene, zylon, nylon, glass, carbon, ultrahigh molecular weight polyethylene, p-phenylene-2,6-benzobisoxazole) fiber. For example, products for the fiber, such as "Kevlar", "Twaron", "Heracron", "Spectra", "Dyneema", "Zylon", "Gore- Dacron "and the like can be used.

The nanoparticles may comprise silica or alumina. When the diameter of the nanoparticles is 3,000 nm or more, the shear thickening phenomenon does not occur. Therefore, the diameter of the nanoparticles may be 10 nm or more and 3,000 nm or less, preferably 10 nm or more and 1,000 nm or less, and more preferably 20 nm or more and 500 nm or less.

The nanoparticles may be dispersed in a nonvolatile dispersion medium such as polyethylene glycol. The number average molecular weight of the polyethylene glycol may be 200 to 500. [

The content of the nanoparticles in the shear thickening fluid may be about 50% to 80% by weight.

In the shearing-impregnated woven fabric layer 20, the content of the shear-thickening fluid may vary depending on the impact resistance property to be obtained and the like, but may be 60 wt% or more, for example, 60 wt% to 80 wt% %. ≪ / RTI >

The size of the nanoparticles may vary depending on the desired impact resistance properties to be obtained. For example, the critical shear rate of the shear thickening effect at the shear rate corresponding to the target impact velocity band can be designed to be consistent. In addition, a plurality of shear-thickening fabric layers including particles of different sizes may be laminated and designed to have excellent impact resistance in a wide speed band.

The shear thickening fluid may further comprise a radiopaque filler to block electromagnetic radiation. For example, the filler may comprise an inorganic salt comprising a radiopaque cation. For example, the filler may comprise salts of barium, iodine, bismuth, uranium, zirconium. For example, the filler may comprise barium sulfate. Accordingly, the sheared thickened fabric layer 20 may have a radiation shielding function as well as an impact resistance function.

The sheath thickened fabric layer 20 may be laminated with a plurality of layers, for example, but it is not limited thereto.

The antistatic layer 30 may perform a function of charging static electricity. As the antistatic layer 30, various materials having charging performance and flexibility may be used. For example, a metal-coated fiber assembly, a metal-coated fabric, a metal-coated polymer film, or a conductive carbon structure such as graphene may be used. For example, the metal may include nickel, copper, titanium, chromium, silver, and the like. The polymer or fiber may include polyester, polyamide (nylon), polyethylene, polypropylene and the like. These may be used alone or in combination.

For example, the antistatic layer 30 may have a thickness of 50 um to 400 um, but is not limited thereto.

The strength reinforcing layer 40 reinforces the strength of the composite. Preferably, the strength-enhancing layer 40 may comprise a fabric, such as a high-strength ripstop. Preferably, the fabric is coated with a synthetic rubber such as neoprene. In another embodiment, the strength-enhancing layer 40 may be fabric coated with nickel, copper, silver, etc. so as to have a charging function and an electromagnetic radiation shielding function.

For example, the strength-enhancing layer 40 may have a thickness of 20 um to 100 um, but is not limited thereto.

The reflective layer 10, the front end thickened fabric layer 20, the antistatic layer 30 and the strength reinforcing layer 40 are laminated in a free boundary condition so that a fiber pull-out mechanism can be implemented But may be partially fixed or coupled for use.

The impact-resistant flexible composite is highly utilizable by using a flexible material such as a fabric or a polymer film as a whole. For example, when not in use, it is easy to fold and store, and can be provided in various forms. Therefore, various applications as an impact resistant material are possible.

In addition, the impact resistant flexible composite provides high impact resistance in comparison with small volume and weight using a shear thickening fluid.

In addition, the impact-resistant flexible composite has a reflective function, an antistatic function, an electromagnetic wave shielding function, and the like, thereby providing excellent heat insulation performance in a harsh environment such as an outer space, Can be protected.

When the impact resistant flexible composite is used in an outer space, the reflective layer 10 corresponds to the outermost layer facing the sun, and the strength reinforcing layer 40 is applied to the object to be protected (e.g., worker, work equipment, space structure) . The stacking order of the front end thickened fabric layer 20, the antistatic layer 30, and the strength reinforcing layer 40 may be appropriately changed.

Further, in another embodiment, at least one of the antistatic layer 30 and the strength reinforcing layer 40 may be omitted.

Variable Protection Device

FIG. 2 is a perspective view illustrating a configuration variable protective device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of the protective device of Fig. Specifically, the upper drawing shows the protective device in the contracted state, and the lower figure shows the protective device in the expanded state.

Referring to FIGS. 2 and 3, the variable protection device includes a protective sheet 110 and a support 120.

Since the protective sheet 110 is the same as the shockproof flexible composite according to the embodiment of the present invention shown in FIG. 1, the overlapping description may be omitted.

At least a part of the support portion 120 is made of a shape memory alloy. The shape memory alloy can return to the shape of the mother phase by the change of the temperature. Therefore, it is possible to change the shape of the protective device without a complicated mechanical configuration or actuator.

For example, the support 120 may include a central support portion 122, a first support portion 124, and a second support portion 126 in the form of a cross. The center support portion 122 may have a cross shape extending in a first direction D1 and a second direction D2 perpendicular to the first direction.

The first support portion 124 extends along the first direction D1 and is coupled to the center support portion 122. [ The second support portion 126 extends along the second direction D2 and is coupled to the center support portion 122. The first support portion 124 and the second support portion 126 are in contact with the protective sheet 110 and engage with the protective sheet 110 on at least a part of the contacting surface. Therefore, the protective sheet 110 changes together with changes in the shape of the support portion.

A plurality of first support portions 124 are disposed to be spaced apart from each other along the second direction D2 and a plurality of second support portions 126 are disposed to be spaced apart from each other along the first direction D1. Accordingly, the first support part 124 and the second support part 126 form a grid array of check pattern shapes. It is preferable that the first support part 124 and the second support part 126 are not directly coupled to each other so that their behavior is not interfered with each other.

2 and 3, the first support portion 124 and the second support portion 126 are bent to have a concave-convex shape (or zigzag shape) at a low temperature, and heat It can be deformed into a linear shape as shown at the lower end. For example, when the protecting device is used in an outer space, when the supporting part is heated by sunlight or the like, the supporting part is deformed into a straight shape, and when the protecting sheet 110 is unfolded, As the additional cooling is performed, the protective sheet 110 can be folded as it is deformed into the concavo-convex shape. In addition, deformation can be actively controlled by using a separate heat source such as a hot wire so that the deformation of the protective device does not depend on the sunlight.

 Although the deformation of the second support portion 126 is shown in Fig. 3, the first support portion 124 and the central support portion 122 may also be deformed in a similar manner.

As the shape memory alloy, those known in the art can be used. For example, a copper-zinc-aluminum alloy, a copper-aluminum-nickel alloy, a nickel-titanium alloy, a nickel-titanium-hafnium alloy and the like may be used.

The protection device according to the present invention can change the shape of the protection device by using the flexible protection sheet and the shape memory alloy support coupled thereto. The protective device can expand or collapse the protective sheet without a separate actuator. Therefore, it can be usefully used in an outer space or the like.

The supporting portion using the shape memory alloy may have various shapes other than those shown in Figs. For example, in the above embodiment, the first support portion 124 and the second support portion 126 are all formed of a shape memory alloy so that the protective sheet 110 is held in the first direction D1 and the second direction D2 The first support portion 124 is formed of a shape memory alloy and the second support portion 125 is formed of a general material so that the protective sheet 110 is extended in the first direction D1 It may be configured to be unfolded and folded.

4 is a plan view showing a variable protective device according to another embodiment of the present invention.

Referring to FIG. 4, the shape variable protective device includes a protective sheet 210 and a support 220. The support portion 220 may include a main support portion 222 and a sub support portion 224 in a radial direction. For example, the main support 222 may have a cross shape, and at least one sub support portion 224 may be disposed between the branches of the main support portion 222 to have a generally radial shape. Preferably, the sub-support 224 may have a smaller width than the main support 222.

The support part 220 may be formed to have a straight shape at a high temperature and a curved shape at a low temperature. In this case, as shown in FIG. 4, the protective sheet 220 may have a contracted shape at a low temperature and an expanded shape at a high temperature, so that the folding and spreading of the protective sheet 220 can be performed.

The protective sheet 210 may have various shapes such as a circular shape, an elliptical shape, a triangular shape, a square shape, a hexagonal shape, and an octagonal shape, if necessary.

5 is a view schematically showing an example of use of the variable protective device of the present invention.

Referring to FIG. 5, the variable guard device of the present invention can be used in an outer space. For example, the shape-variable protective device 200 may be connected to a robot 300 working in space to protect the robot 300. The robot 300 can perform an operation such as repair of the satellite 400. The shape variable protective device 200 spreads the protective sheet by the solar heat to remove the robot 300 from the space debris, Can be protected.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. You will understand.

The present invention can be used in protection devices in industrial sites, space, and the like.

Claims (17)

Reflective layer;
An antistatic layer having electrical conductivity;
A strength reinforcing layer comprising a fabric; And
An impact resistant flexible composite comprising a sheathed thickened fabric layer comprising a fabric impregnated in a shear-thickening fluid, said reflective layer being located at an outermost position. The impact resistant flexible composite according to claim 1, wherein the reflective layer comprises a polymer film combined with a metal thin film. The impact resistant flexible composite according to claim 1, wherein the shear thickening fluid comprises silica or aluminum nanoparticles dispersed in a nonvolatile dispersion medium. The fabric of claim 1, wherein the fabric of the shear thickened fabric layer is selected from the group consisting of aramid fibers, polyethylene fibers, polypropylene fibers, zylon fibers, nylon fibers, glass fibers, carbon fibers, ultra high molecular weight polyethylene An ultra-high molecular weight polyethylene (PBT) fiber, and a PBO (p-phenylene-2,6-benzobisoxazole) fiber. The impact resistant flexible composite of claim 1 wherein the shear thickened fabric layer comprises 60 wt% to 80 wt% of shear thickening fluid. The impact resistant flexible composite of claim 1, wherein the shear thickened fabric layer further comprises a radiation resilient filler comprising a salt of barium, iodine, bismuth, uranium or zirconium. delete The method of claim 1, wherein the antistatic layer comprises at least one selected from the group consisting of a metal-coated fibrous assembly, a metal-coated fabric, a metal-coated polymer film, and a conductive carbon structure. Complex. The impact resistant flexible composite according to claim 1, wherein the fabric of the strength reinforcing layer is coated with synthetic rubber. delete A protective sheet comprising a sheath thickened fabric layer comprising a reflective layer, an antistatic layer having electrical conductivity, a strength enhancing layer comprising a fabric and a fabric impregnated in a shear thickening fluid, said reflective layer being located at an outermost position; And
And a shape memory alloy support portion coupled to the protective sheet and capable of expanding or collapsing the protective sheet according to a temperature change. delete 12. The method of claim 11,
Wherein the reflective layer comprises a polymer film combined with a metal thin film,
Wherein the shear thickening fluid comprises silica or aluminum nanoparticles dispersed in a nonvolatile dispersion medium,
Wherein the antistatic layer comprises at least one selected from the group consisting of a metal-coated fiber assembly, a metal-coated fabric, a metal-coated polymer film, and a conductive carbon structure,
Wherein the fabric of the strength reinforcing layer is coated with synthetic rubber. 12. The semiconductor memory device according to claim 11,
A cross-shaped central support;
A first support extending in a first direction and coupled to the central support; And
And a second support portion extending in a second direction perpendicular to the first direction and coupled to the center support portion and not fixed to the first support portion. 15. The variable shape variable protective device according to claim 14, wherein the first support portion or the second support portion is bent in a zigzag shape at a specific temperature. 12. The semiconductor memory device according to claim 11,
A radial main support portion; And
And at least one sub-support portion disposed between the branches of the main support portion and having a smaller width than the main support portion. Claim 17 has been abandoned due to the setting registration fee. 12. The method of claim 11, wherein the shape memory alloy support comprises at least one selected from the group consisting of a copper-zinc-aluminum alloy, a copper-aluminum-nickel alloy, a nickel-titanium alloy and a nickel-titanium- Shaped variable protective device.

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