JPH11278894A - Multistylus structure fiber and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the reinforcing effect of a material by forming plural fine fiber-shaped acicular bodies so that they are nearly radially spread from the surface of a core body. SOLUTION: A core body 10 is melted or sufficiently softened by heating, the tip of a needle 20 is driven into the core body 10 and the needle 20 with the softened resin sticking to the tip is separated from the core body 10 at a prescribed rate. At the time when a formed acicular body 11 attains to a prescribed length, the tip of the acicular body 11 is cut to form an acicular body 11 of a prescribed shape. Plural fine fiber-shaped acicular bodies 11 are formed so that they are nearly radially spread from the surface of the core body 10 and the objective multistylus structure fiber is obtd. This fiber is mixed into cement mortar or cement concrete as a matrix material at a prescribed mixing rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-needle structure fiber and a method for producing the same, and more particularly, to a fiber material which can be homogeneously dispersed and mixed in a matrix material such as concrete or mortar to enhance the reinforcing effect of the material. And a method for producing the same.

[0002]

2. Description of the Related Art Steel fiber reinforced concrete is known as a concrete composite material in the fields of construction and civil engineering. The steel fiber reinforced concrete is a composite material in which short steel fibers as a reinforcing material are dispersed and mixed in concrete as a matrix material. The steel fibers are distributed evenly in the matrix, and the distributed steel fibers bear the tensile force in the cross section to improve crack dispersibility and restraint, and toughness, bending strength, The tensile strength can be greatly improved. As the steel fiber, a drawn linear steel wire having a cross section of about 0.2 to 0.5 mmφ (or one side) and a length of L = about 30 to 50 mm is used. As a material of the steel wire, a drawn wire of ordinary steel or stainless steel is used.
Recently, glass fibers, synthetic resin fibers, carbon fibers, and the like have been developed as short fibers instead of steel fibers.

[0003] Since conventional short fibers of this kind are handled as loose pieces, a disperser or the like is used to efficiently disperse and mix a large amount of short fibers into concrete as a matrix material. I have. However, even if a dispersing machine is used, as shown in FIG. 5 (a), the short fibers 50 may be entangled with each other and put into a ball-like state into a mixer (not shown) to form a so-called fiber ball. Many. In addition, the short fibers 50 in the form of fiber balls, when kneaded, embrace the mortar component 51 as shown in FIG.

Therefore, in order to eliminate the entanglement of the short fibers 50 during kneading, as shown in FIG. 6, as an example, a large number of short fibers 50 are aligned in a plate shape, and the short fibers 50 are separated. A plate-like short fiber 55 temporarily fixed with a water-soluble adhesive 52 has also been developed. When this plate-like short fiber 55 is used,
When the short fibers are supplied, the short fibers 50 are integrally formed into a plate shape, so that no fiber ball is formed, and the adhesive 52 between the short fibers 50 is dissolved by the water added in the kneading stage. The adhesive is removed, and the mixture is dispersed in the concrete by kneading and stirring.

[0005]

However, since these short fibers are almost linear in shape, when mixed in a matrix, it is difficult to uniformly disperse or orient the fibers and to form a fiber ball. There is a problem that it is easy to do. Further, the adhesive force with the matrix is weak.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, to form a three-dimensional multi-needle shape, to obtain the integrality with the matrix when mixed into the matrix, An object of the present invention is to provide a multi-needle structural fiber capable of exhibiting a reinforcing effect and a method for producing the same.

[0007]

In order to achieve the above object, the present invention is characterized in that a plurality of small-diameter fibrous needle-like bodies are formed so as to be substantially radial from the surface of the core. Is what you do.

Further, as a method for producing the core, a needle is driven into the surface of a core in a molten or softened state, and the needle is pulled out from the core with a part of the core attached to the tip of the needle. A small-diameter fibrous needle-like body is formed, and a plurality of needle-like bodies are formed on the surface of the core.

It is preferable that the above-mentioned multi-needle structural fibers are mixed with a predetermined mixing ratio in cement mortar or cement concrete as a matrix material and used.
Further, the core is preferably made of a thermoplastic resin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the multi-needle structure fiber of the present invention and a method for producing the same will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing each form of a synthetic resin multi-needle structural fiber (hereinafter, referred to as a multi-needle fiber) for reinforcing a matrix material according to the present invention. FIG. 1A shows a multi-needle structural fiber in which a plurality of needles 11 are formed from a ball-shaped core 10. In the present embodiment, ten needles 11 from the core 10 are shown. Are formed so as to protrude radially. In the present embodiment, the needle 11
Is composed of resin fibers formed from a core body 10 made of a thermoplastic resin by a predetermined drawing method.

FIG. 1 (b) shows a cylindrical pellet 10
FIG. 9 is a perspective view showing another embodiment in which needle-like bodies 11 are radially formed. The needle-shaped body 11 extending radially from the core 10 can be formed integrally with the core 10 by drawing a part of the core 10 as described later. For this reason, it is preferable that the volume of the core body 10 before forming the needle-shaped body 11 is set to a size in consideration of the volume of the needle-shaped body 11 to be formed even in the case of a ball-shaped or cylindrical pellet.

In the present embodiment, a polyvinyl alcohol-based resin is used as the thermoplastic resin serving as the core 10. In addition, polypropylene, polyacrylonitrile,
Each thermoplastic resin such as polyethylene is suitable from the viewpoint of alkali resistance to cement. Further, in addition to these thermoplastic resins having a low melting temperature, glass and carbon fiber pellets can be used.

FIG. 2 is a front view for explaining the shape and dimensions of the multi-needle-like body 11 shown in FIG. As shown in the figure, the total length L of the needle 11 extending from the core 10
Depends on the material of the core 10, but can be set to about L = 5 to 60 mm. The fiber diameter d at this time is d = 10
It is about 500 μm. The final size of the diameter D of the core body 10 is determined according to the number of the formed needle-like bodies 11, and the needle-like body 1 is set so that D = about 0.2 to 2.0 mm.
It is preferable to set a dimension (volume) before one processing.

A method for forming the needle-shaped body 11 will be described with reference to FIGS. First, the core 10 serving as the base of the multi-needle fiber 11 shown in FIG. 3A is heated until the melting temperature or the core 10 itself is sufficiently softened. Then, the tip of the needle 20 is driven into the core 10 in this state (see FIG. 3B). With the softened resin adhered to the tip of the needle 20, the needle 20 is moved at a predetermined moving speed so as to be separated from the core 10 (see FIG. 3C). When the needle 11 reaches a predetermined length, the needle 1
1 is cut off to form a needle-shaped body 11 having a predetermined shape.
A predetermined number of needles 11 are formed on the surface of the core 10 by this molding operation.

FIG. 3D shows a multi-needle fiber 1 in which four needle-like bodies 11 forming a cross are formed on the surface of a core body 10. This needle-like body 11 is formed simultaneously with a large number of needles 2.
Alternatively, the needle 20 or the core 10 may be moved along a predetermined path to form the needle 11. In the method of forming the needle-shaped body 11, the core 10 is in a molten state. However, when a material having a low melting point is used as the core 10, the needle 20 may be heated to perform the drawing operation. Although only one needle 20 is shown in FIG. 3, it is also possible to drive many needles 20 toward the core 10 and simultaneously form many needles 11. Although the needle 20 shown in the figure is a solid needle with a sharp tip, the tip may be bent into an L-shape or a hollow pipe.

As another method for forming the needle-shaped body, it is also possible to blow a small-diameter pipe-shaped nozzle into a molten core, blow compressed air from the nozzle, and perform blow molding.

FIG. 4 is a partially enlarged view showing an example of the shape of the needle 11. FIG. 3 shows an example in which the straight rod-like needle 11 shown in FIG. 4 (a) is formed on the surface of the core 10. However, in these examples, the needle 20 (FIG. 3) is pulled out when the needle 11 is formed. Curing is performed while changing the speed or changing the drawing direction from front to back and right and left, and changing the shape so as to have a predetermined shape during the drawing process. FIG.
(B) shows an example in which the thickness of the needle-like body 11 is changed in multiple stages. The strength of the needle-like body 11 is increased by thickening the root portion, and the needle-like body 11 is mixed with concrete or the like. 11 can be prevented from breaking. FIG. 4 (c), (d)
Shows an example of a needle-like body 11 formed in a bent line shape having a gentle curved shape or a fine lightning shape. By adopting such a shape, the surface area of the needle-shaped body 11 as a fiber can be increased and the adhesive force can be increased. In addition, since the fibers are flexible, the needle-like bodies 11 are arranged along the aggregates when mixed into concrete or the like, and the bonding force between the aggregates can be improved. FIG. 4 (e),
(F) shows the needle-like body 11 in which a number of knotty ribs 11a are formed along the fiber. Due to the effect of these nodal ribs 11a, the adhesive force of the fiber mixed between the aggregates is remarkably improved.

It is preferable that the fiber diameter of the needle-like body 11 is formed such that the multi-needle fiber 1 is not cut while being kneaded with a matrix such as concrete.
Specifically, it is preferable to fall within the range of the fiber diameter d described above. In the above description, ordinary concrete is given as a matrix material to be mixed with the multi-needle fiber 1, but cement mortar may be used.

[0019]

As is apparent from the above description, according to the present invention, the reinforcing fibers provided with the three-dimensional needles can be uniformly dispersed in the matrix, and as a result, the reinforcing effect of the matrix material can be reduced. There is an effect that it can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a plurality of embodiments of a multi-needle structure fiber according to the present invention.

FIG. 2 is a schematic front view shown for explaining the shape and dimensions of the multi-needle structure fiber shown in FIG. 1 (a).

FIG. 3 is a work explanatory diagram showing a procedure for forming a needle-like body into a core. .

FIG. 4 is a partially enlarged view schematically showing an example of forming a needle-like body.

FIG. 5 is an explanatory view showing an example of a conventional fiber ball formed of short fibers.

FIG. 6 is a perspective view showing a plate-like short fiber temporarily fixed with a conventional water-soluble adhesive.

[Description of Signs] 1 multi-needle fiber 10 core body 11 needle-like body 20 needle

Claims (4)

[Claims] 1. A multi-needle structural fiber, wherein a plurality of small-diameter fibrous needles are formed so as to be substantially radial from the surface of the core. 2. A needle is driven into the surface of a core in a molten or softened state, and the needle is pulled out of the core with a part of the core attached to the tip of the needle, thereby forming a small diameter fiber. A method for producing a multi-needle structure fiber, comprising forming a needle-like body and forming a plurality of needle-like bodies on the surface of the core body. 3. A multi-needle structural fiber characterized in that the multi-needle structural fiber according to claim 1 is mixed at a predetermined mixing ratio into cement mortar or cement concrete as a matrix material. 4. The multi-needle structural fiber according to claim 1, wherein said core is a thermoplastic resin.