KR20190011917A - Fiber reinforcing strip, manufacturing method thereof, and manufacturing apparatus - Google Patents

Abstract

The present invention relates to a fiber reinforcing material and, more specifically, relates to a fiber reinforcing material which is provided with a matrix reinforcing material made of a thermoplastic polymer and a fiber assembly placed in the reinforcing material and having a plurality of fibers arranged in parallel with the reinforcing material. Moreover, a hollow portion is formed in the center of a cross section in a longitudinal direction of the matrix reinforcing material. Therefore, the fiber reinforcing material is lightweight and has excellent flexibility, and further, a perforation is formed to provide an excellent property of matter as a reinforcing material.

Description

Technical Field [0001] The present invention relates to a fiber reinforcing strip, a manufacturing method thereof, and a manufacturing apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforcing material mainly used as a reinforcing material for civil engineering, and more particularly, to a fiber reinforcing material buried in soil during a process of forming a retaining wall to improve the stability of a clayey soil layer, .

Reinforced earth retaining wall acts as a retaining structure to resist back earth pressure by forming reinforcing soil with improved shear strength due to tensile resistance of the reinforcing material installed inside the embankment and bonding force with surrounding soil.

Reinforced earth retaining walls are generally reinforced with stiffeners and consist of a fill and a front wall. As the front wall, a concrete panel, a mortar block, a geotextile, or the like can be used. As the reinforcing material, a band type, a grid type, a front type or a sheet type reinforcing material of metal or geosynthetic fiber material can be used.

The fiber reinforcing materials are used for reinforcement of retaining walls, slope reinforcement, and ground reinforcement in civil engineering work. Due to the characteristics of the application, high tensile strength, low tensile strain and creep deformation characteristics are required, as well as physical properties such as weather resistance and friction characteristics. Also, since it is used as a reinforcing material for civil engineering structures, it is necessary to facilitate handling such as transportation and installation in civil engineering sites. That is, there is a demand for a fiber reinforcing material that is light in weight and easy to construct without greatly deteriorating mechanical properties.

Conventionally, a foaming method is used to lighten the plastic product. However, the pores of the plastic foam are as large as 100 mu m or more, and the distribution of the size is also uneven, and mechanical properties and shape stability are deteriorated. In addition, since the plastic foam is usually produced in a batch-wise manner in which a mixture of a polymer melt and a gas is put into a mold (see EP 432997, US 2005/0256215, US 2007/0202326), there is a problem that the productivity is lowered.

It is an object of the present invention to provide a fiber reinforcing material which is not only light and economical but also minimizes the deterioration of mechanical properties due to the introduction of foam by controlling the amount and size of micro pores of the foam.

The present invention also provides a fiber reinforcing material which is hollow and pierced in a matrix reinforcement to provide excellent workability and physical properties.

The present invention also provides a method and apparatus for producing a fiber reinforcement having the above-mentioned characteristics continuously.

In order to achieve the above object, a fiber reinforcing material according to the present invention is a fiber reinforcing material comprising a matrix reinforcing material made of a thermoplastic polymer and a fiber aggregate positioned inside the matrix reinforcing material and having a plurality of fibers arranged in parallel with the matrix reinforcing material, Wherein the matrix reinforcing material has a cavity formed at a central portion in a longitudinal direction thereof.

Also, the matrix reinforcement is a foam comprising a number of micropores having an average particle size of 0.1 to 60 탆, wherein the porosity is 10 to 70%, and the total cross-sectional area of the fibrous aggregate is 10 To 80% by weight of the fiber reinforcement.

The thermoplastic polymer may be a polyolefin resin having a melt index (MI) of 1 to 35, a polyethylene terephthalate having an intrinsic viscosity (IV) of 0.64 to 1.0, polyamides, one or a mixture of two or more selected from the group consisting of polyacrylates, polyacrylonitrile, polycarbonates, polyvinylchloride, polystyrene and polybutadiene, The present invention also provides a fiber reinforcing material comprising

In addition, the present invention is characterized in that the fibrous aggregate is any fiber selected from the group consisting of polyester fiber, glass fiber, aramid fiber, polyvinyl alcohol fiber, carbon fiber, basalt fiber, stainless steel fiber, copper fiber and amorphous metal fiber, The present invention provides a fiber reinforcing material characterized in that it is composed of ply fibers in which two or more kinds of fibers are laminated.

Further, the present invention provides a method of producing a fiber aggregate, comprising the steps of: (a) preparing a fiber aggregate in which a mixture of a gas and a polymer melt and a plurality of fibers are arranged in parallel; (b) feeding the assembly of fibers to a first inlet of the crosshead, injecting a mixture of the gas and the polymer melt through a second inlet of the crosshead formed around the first inlet, Attaching the fiber aggregate and the mixture of the gas and the polymer melt to each other while moving through the moving path, and discharging the mixture to the outlet of the crosshead; And (c) cooling the resultant of step (b).

In addition, the present invention provides a method of manufacturing a fiber reinforcement further comprising the step of forming perforations in the result of step (c).

Further, the present invention provides a method of manufacturing a fiber reinforcement, wherein the size of the outlet of the crosshead is smaller than the size of the traveling path.

In addition, the present invention provides a method of fabricating a fiber bundle, comprising: a first inlet through which a plurality of fibers are arranged in parallel; A second inlet formed around the first inlet and through which a mixture of gas and polymer melt flows; A moving path communicating with the first inlet and the second inlet and being adhered to each other while the fiber aggregate and the mixture of the gas and the polymer melt are moved; And a crosshead including a fiber bundle adhered to each other and a discharge port through which a mixture of the gas and the polymer melt is discharged to the outside.

In addition, the present invention provides a manufacturing apparatus for a fiber reinforcing material, wherein a hollow forming part is provided between a first inlet and an outlet to form a hollow in the resultant product discharged from the crosshead.

The fibrous reinforcement according to the present invention is not only light and economical because it has a cavity formed at the center of its end face and is provided with a matrix reinforcing material as a foam, and also controls the amount and size of the fine pore size of the foam, It can be minimized and can be usefully used as a reinforcing material.

Further, according to the fiber reinforcing material producing method of the present invention, a fiber reinforcing material which is light and excellent in mechanical properties can be continuously produced.

Further, the fiber reinforcing material of the present invention can be easily folded by the hollow, so that there is an effect of facilitating the construction, and a high tensile strength by the hollow and the punching, and the excellent workability and friction characteristics are also obtained.

1 is a partially enlarged perspective view schematically showing a fiber reinforcing material of the present invention.
2 is a view illustrating a manufacturing process of a fiber reinforcement according to an embodiment of the present invention.
3 is a cross-sectional view schematically showing an assembly of the fiber reinforcing material manufacturing apparatus of the present invention.
4 is a view showing a nipple constituting an assembly of the fiber reinforcing material manufacturing apparatus of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

The terms " about ", " substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation of, or approximation to, the numerical values of manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

1, the fiber reinforcing member 1 according to the present invention can be formed by including a matrix reinforcing material 2 made of a thermoplastic polymer and a fiber aggregate 3 located inside the matrix reinforcing material.

The fibrous assembly 3 is formed by arranging a plurality of fibers in parallel with the matrix reinforcement 2. The matrix reinforcement 2 is formed of a foam and can form a hollow in the longitudinal direction.

Preferably, the foam is formed to include a plurality of micropores having an average particle diameter of 0.1 to 60 탆, and the porosity is adjusted to 10 to 70%.

When the average particle diameter of the micropores contained in the matrix reinforcing material foam is less than 0.1 탆, it is difficult to form microvoids. If the porosity is less than 10%, the specific gravity of the matrix reinforcing material is increased and the reinforcing material is not lightened. have. If the average particle diameter is more than 60 占 퐉 and the porosity is more than 70%, the mechanical properties of the reinforcing material may be deteriorated due to excessive pore formation, and it may be difficult to prevent damage due to the aggregate of the reinforcing fibers.

The total cross-sectional area of the fibrous aggregate (3) is 10 to 80% of the total cross-sectional area of the fiber reinforcing material, which is not only light and economical, but also minimizes the deterioration of the mechanical properties due to the introduction of the foam.

If the total cross-sectional area of the fibrous aggregate is less than 10% of the total cross-sectional area of the fibrous reinforcement, the reinforcing effect by the fibrous aggregate is insignificant. If the cross-sectional area exceeds 80%, the thickness of the matrix reinforcing material becomes too thin, It is possible to easily receive the damage.

As the thermoplastic polymer constituting the matrix reinforcing material, any of polymer matrix resins used for producing fiber reinforcing materials can be used. For example, a polyolefin resin having a melt index (MI) of 1 to 35 and an intrinsic viscosity (IV) of 0.64 Polyolefins such as polyethylene terephthalate, polyamides, polyacrylates, polyacrylonitrile, polycarbonates, polyvinylechloride, polystyrene, polystyrene, Polybutadiene, or the like, or a mixture of two or more of them may be used.

Also, the fiber aggregate can be used as long as it is a collection of fibers used for manufacturing fiber reinforcing materials, such as polyester fiber, glass fiber, aramid fiber, polyvinyl alcohol fiber, carbon fiber, basalt fiber, stainless steel fiber, Amorphous metal fibers and the like may be used singly or two or more kinds of these fibers may be used in tandem.

Such a fiber reinforcing material can be produced in a shape having a rectangular cross-sectional thickness. Preferably, the fiber reinforcing material has a width of 50 to 120 mm (more preferably 70 to 100 mm) and a thickness of 1 to 5 mm (more preferably 1.5 to 3.5 lt; RTI ID = 0.0 > mm). < / RTI >

In the present invention, a longitudinal hollow may be formed at the center of the matrix reinforcement. The hollow can be formed by the applicant by arbitrarily selecting the center portion of the cross section, the uniformly divided portion, and the nonuniformly divided portion. FIG. 1 is a perspective view illustrating a hollow in a longitudinal direction at a center of a cross section according to an embodiment of the present invention. Since the hollow is formed in the matrix reinforcing material, it is light and economical, and the overall flexibility is high, so that the construction can be convenient.

In addition, the present invention is characterized in that a perforation is formed in the fiber reinforcing material, and the upper and lower portions of the fiber reinforcing material are integrated with the soil through the perforation to improve the frictional force between the fiber reinforcing material and the soil, have.

A method of manufacturing the fiber reinforcement of the present invention will be described with reference to Fig.

First, a fiber aggregate in which a plurality of fibers are arranged in parallel and a mixture of a gas and a polymer melt are prepared.

The fibrous aggregates 3 are prepared according to a conventional method using the above-mentioned fibers, and a mixture of gas and polymer melt (hereinafter referred to as gas / polymer mixture) is prepared by melt-kneading the polymer resin in the extruder 6 A blowing agent which generates gas by pyrolysis together with a polymer resin is injected into the extruder 6 to prepare a mixture of a homogeneous gas and a polymer melt in the extruder 6. [ It is preferable to use a supercritical fluid such as carbon dioxide (CO ₂ ) or nitrogen (N ₂ ) when introducing gas directly. In the case of introducing a foaming agent such as a polymer resin, a foaming agent may be separately added, In the form of a pellet mixed with water.

Next, the gas / polymer mixture in the extruder 6 is transferred to the crosshead 13 on which the fiber aggregate 3 is mounted using a gear pump, so that the gas / polymer compound and the fiber aggregate 3 And then the fiber aggregate 3 to which the gas / polymer compound is adhered is discharged to the outside of the crosshead 13. At this time, by the pressure difference between the pressure in the crosshead 13 and the atmospheric pressure, a fiber reinforcing member 1 having a micro-expanded structure formed by expanding the gas melted in the polymer resin and a hollow formed by the hollow forming portion is produced.

Next, the fibrous reinforcement 1 of the continuously extruded micro-expanded structure is passed through the cooling water tank 16 to prevent the pores formed in the polymer resin from collapsing or the gas from escaping out of the polymer resin. When the foamed matrix reinforcing material is not cooled, a foam having a desired porosity can not be obtained, and a foam having small and uniform pores can not be obtained.

Next, the fiber reinforcing member 1 having the microfused foamed structure is perforated in the perforations 17 in the longitudinal direction at regular intervals, and then wound in a predetermined length to the bobbin at a speed of 2 to 20 m / min.

 The perforation 17 is a perforation 17 for perforating the perforations 4 in the center section 5 of the hollow fiber reinforcing member of FIG. 1 and capable of holding the continuous fiber reinforcing member 1, It consists of government and perforating equipment. The punching apparatus may be a conventional press apparatus, and it may be more preferable to use an ultrasonic welder. Frictional heat is generated in the center of the hollow fiber reinforcing member by using the ultrasonic welder to form a molten state, and then it is pressurized by the engraved roller to form perforations.

The present invention will be described in more detail with reference to the apparatus for manufacturing a fiber reinforcing material of the present invention and the process drawing. A gas injection device 8 composed of a high-pressure metering pump 10 for quantitatively injecting the gas supplied from the gas tank 9, a fiber assembly (not shown) A fiber supply device 12 for supplying a fiber bundle 3 to the crosshead 13 of the extruder at a constant speed and a fiber bundle 3 to which the molten polymer resin and the fiber aggregate 3 meet, A cross head 13 for forming the reinforcing material 1, a knurling device 15 for imparting concave and convex to the fiber reinforcing material coming out of the crosshead 13, a cooling device 16 for cooling the fiber reinforcing material with irregularities, A perforation 17 for perforating the cooled fiber reinforcement, a winding device 18 for pulling the perforated fiber reinforcement at a constant speed, and a winder 19 for winding the fiber reinforcement at a constant length.

The construction of the reinforcing material manufacturing process will be described in detail as follows.

2, first, the fiber aggregate 3 is passed through the fiber feeding device 12. As shown in FIG. The fiber supply device 12 regulates the speed at which the fiber aggregate 3 is introduced into the crosshead 13 and the winding device 18 regulates the speed at which the fiber reinforcing material 1 is pulled, Tension is maintained. The fiber aggregate 3 having passed through the fiber supply device 12 passes through the crosshead 13. [

2, the polymer resin in the form of pellets is fed into the extruder 6 through the hopper 7. [ The polymeric resin in the form of a pellet forming the matrix stiffener 2 releases gas upon decomposition to form a gas / polymer mixture in the extruder. The foam gas can also be directly introduced into the barrel of the extruder 6 by using the high-pressure metering pump 10 by using the gas injector 8.

The gas / polymer mixture is transported to the crosshead 13 where the fiber aggregate is located. The fibrous aggregate and the gas / polymer mixture adhere to each other in the assembly 20 as shown in Fig. 3 in the crosshead 13. The assembly 20 comprises a nipple 21, a bushing 22, and a die 23. The nipple 21 is formed with a first inlet 24 through which the fiber aggregate 3 flows and a second inlet 25 through which the gas / polymer mixture flows. The second inlet 25 is preferably formed around the first inlet 24 because it is advantageous to fully coat the fiber aggregate 3 using a gas / polymer mixture.

The first inlet 24 of the nipple 21 positions the fiber aggregate 3 in the fiber reinforcing member 1 so as to be located at the center of the fiber reinforcing member 1, The fibrous aggregate (3) and the gas / polymer compound are attached. The die 23 is designed so that the bonded fiber bundle 3 and the gas / polymer resin mixture are subjected to a high pressure, and the shape of the stiffener 1 can be determined according to the shape of the transfer path 23a of the die. In an embodiment of the present invention, the hollow forming portion 26 may be positioned from the nipple through the bushing moving path 22a to the die moving path 23a to form a hollow at the center of the end face of the stiffener. The shape, size or position of the hollow can be adjusted by changing the shape of the hollow forming part.

The fiber reinforcing member 1 that has passed through the crosshead 13 passes through a cooling water tank 16 whose temperature can be adjusted so that the gas in the matrix reinforcing member is not discharged to the outside. The fiber reinforcing member 1 thus cooled is perforated uniformly in the longitudinal direction at the perforation 17 and then wound by a winder 19 to a predetermined length through the winding device 18. [

As described above, the fiber reinforcing material (1) having a microporous structure and a hollow prepared by the method of the present invention does not significantly decrease the mechanical strength as compared with the non-foamed fiber reinforcing material and has uniform micropores, It is possible to reduce the raw material cost per unit volume.

In the present invention, the porosity is calculated by the following equation.

Porosity ( % ) = ( ρN  - ρF ) / ρN  X 100

Where ρN is the density of the non-foamed material, and ρF is the density of the foamed material.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.

The physical property measurement method of the embodiment is as follows.

◈ Density: ASTM D 792

After cutting the fiber reinforcement 1 to a certain length and removing the fibers, the density (d) is calculated by measuring the mass (m) and the volume (V).

d = m / V

◈ Size of air gap

After breaking the fiber reinforcement 1, the cross section is measured using an electron microscope (SEM).

◈ Tensile strength and elongation: ASTM D 6637

The tensile stress due to tensile deformation is measured by applying a tensile force at a rate of 10 ± 3% / min between the clamps on the top and bottom of the strain-controlled tensile tester.

Example  One

The polyester high strength yarn with a fineness of 40000 denier was divided into 8 bundles and passed through a circular cross-section nipple 21, a bushing 22 and a square die 23 of an 8 hole, and a high density polyethylene resin and 1.2 wt% Polymer mixture to the crosshead 13 to extrude the mixture of the fiber bundle and the gas / polymer mixture, to pass through the cooling water tank 16 at 20 占 폚, and then to the extruder 6 preheated at 230 占 폚 to melt and knead , Cooled, punched at a predetermined interval in the perforations, and wound at 5 m / min to prepare a fiber reinforcing material (1) having a microporous structure and a hollow having a width of 70 mm and a thickness of 2.5 mm.

Example  2

A fiber reinforcing material (1) having a microporous structure and a hollow was produced in the same manner as in Example 1, except that the width and the thickness were changed to 90 mm and 2.0 mm, respectively.

Example  3

A fiber reinforcing material (1) having a microcellular structure was prepared in the same manner as in Example 1, except that the polymer resin was changed to linear low density polyethylene.

Example  4

A fiber reinforcing material (1) having a microcellular structure was prepared in the same manner as in Example 1, except that the polymer resin was changed to polypropylene.

Example  5

The same procedure as in Example 1 was carried out except that the die 23 in which the fineness of the fiber aggregate 3 was changed to 24000 denier and the reinforcement 1 having a width of 70 mm and a thickness of 2.1 mm was produced was used, (1). ≪ tb > < TABLE >

Comparative Example  One

A fiber reinforcing material was prepared in the same manner as in Example 1 without using a foaming agent.

Comparative Example  2

A fiber reinforcing material was prepared in the same manner as in Example 1, except that the foaming agent and the assembly 20 of Fig. 3 were not used and the punching was not performed.

The physical properties of the fiber reinforcing material (1) prepared in Examples and Comparative Examples are shown in Table 1 below.

Unit weight
(g / m 2) Average air gap
Size (㎛) Strong (kN) Shinto (%) LASE 5%
(kN) Flexural strength
(kgf) Example 1 120.5 36 37.8 11.9 13.1 0.73 Example 2 121.8 42 37.8 11.4 13.2 0.75 Example 3 115.9 45 37.2 11.4 13.3 0.76 Example 4 117.1 46 37.3 11.2 13.1 0.75 Example 5 94.6 39 22.8 11.9 8.3 0.72 Comparative Example 1 136.9 - 37.2 11.8 13.2 0.86 Comparative Example 2 130.2 40 37.2 11.8 13.0 0.80

As shown in Table 1, the fiber reinforcing material 1 having a microcellular structure manufactured according to the embodiment of the present invention has an average pore size of 36 to 46 μm, It is more flexible than the non-foamed fiber reinforcing material of Comparative Example 1 because the properties are similar to those of the fiber reinforcing material and the flexural strength is low. In Example 1 and Comparative Example 2, the average void and physical properties were similar, but Example 1 in which hollow was hollow had lower unit weight and lower flexural strength than Comparative Example 2 in which there was no hollow and punch Able to know. Thus, it can be seen that fiber reinforcing materials with hollows and perforations are lighter and more flexible. This can provide convenience to the user when constructing the fiber reinforcement.

1: fiber reinforcing material 2: matrix reinforcing material
3: fiber aggregate 4: perforation
5: center part 6: extruder
7: hopper 8: gas injection device
9: Gas tank 10: High-pressure metering pump
11: Krill 12: Fiber supply device
13: Crosshead 14: Mac
15: Knurling device 16: Cooling water tank
17: Thinning 18: Winding device
19: Winder 20: Assembly
21: Nipples 22: Bushings
23: die 24: first inlet
25: second inlet 26: hollow forming part

Claims (9)

1. A fiber reinforcing material comprising a matrix reinforcing material made of a thermoplastic polymer and a fiber aggregate located inside the matrix reinforcing material and having a plurality of fibers arranged in parallel with the matrix reinforcing material,
Wherein the matrix reinforcing material has a hollow at a central portion in a longitudinal direction thereof.
The method according to claim 1,
Wherein the matrix reinforcement is a foam comprising a plurality of micropores having an average particle diameter of 0.1 to 60 탆, the void ratio being 10 to 70%
Wherein the total cross-sectional area of the fibrous aggregate is 10 to 80% of the total cross-sectional area of the fibrous reinforcement.
The method according to claim 1,
Wherein the thermoplastic polymer is a polyolefin resin having a melt index (MI) of 1 to 35, polyethylene terephthalate having an intrinsic viscosity (IV) of 0.64 to 1.0, polyamides, polyacrylates, poly Wherein the fiber is one selected from the group consisting of polyacrylonitrile, polycarbonate, polyvinylchloride, polystyrene and polybutadiene or a mixture of two or more thereof. reinforcement.
The method according to claim 1,
The fiber aggregate may be any fiber selected from the group consisting of a polyester fiber, a glass fiber, an aramid fiber, a polyvinyl alcohol fiber, a carbon fiber, a basalt fiber, a stainless steel fiber, a copper fiber and an amorphous metal fiber, Wherein the fiber reinforcing material is composed of folded synthetic fibers.
(a) preparing a mixture of a gas and a polymer melt and a fiber aggregate in which a plurality of fibers are arranged in parallel;
(b) feeding the fiber aggregate to a first inlet of the crosshead, injecting a mixture of the gas and the polymer melt through a second inlet of the crosshead formed around the first inlet, Attaching the fiber aggregate and the mixture of the gas and the polymer melt to each other while moving through the moving path, and discharging the mixture to the outlet of the crosshead; And
(c) cooling the resultant of step (b).
6. The method of claim 5,
And forming a perforation in the resultant of step (c).
6. The method of claim 5,
Wherein the size of the outlet of the crosshead is smaller than the size of the traveling path.
A first inlet through which a plurality of fibers are arranged in parallel;
A second inlet formed around the first inlet and through which a mixture of gas and polymer melt flows;
A moving path communicating with the first inlet and the second inlet and being adhered to each other while the fiber aggregate and the mixture of the gas and the polymer melt are moved; And
And a crosshead including an outlet through which a mixture of the fiber aggregates attached to each other and a mixture of the gas and the polymer melt is discharged to the outside.
9. The method of claim 8,
Wherein a hollow forming portion is provided between the first inlet and the outlet to form a hollow in the resultant product discharged from the crosshead.

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