JP6701589B2 - Reinforced fiber sheet - Google Patents

Description

  The present invention relates to a reinforcing fiber sheet formed by arranging a large number of reinforcing fiber yarns in a plane, and more particularly to a reinforcing fiber sheet which has high shapeability and can secure high strength after curing because it is easily stretched in one direction.

BACKGROUND OF THE INVENTION Reinforcing fiber sheets formed by arranging a large number of reinforcing fiber yarns on a plane are lightweight, have high rigidity, and are excellent in moldability, and are therefore used in various fields.
For example, in the repair/reinforcement work of the cracked part of the sewer pipe, the pressure (air pressure or water pressure) is applied to the tubular reinforcing fiber sheet impregnated with the curable resin in the radial direction to the circumferential direction. Extend to expand the diameter. As a result, the reinforcing fiber sheet can be cured while being in close contact with the inner peripheral surface of the sewer pipe.
In addition, the strength of the mold may be increased by attaching the reinforcing fiber sheet to a molding die and curing it, or the cured reinforcing fiber sheet itself may be used as an outer shell of a product.

Here, generally, the reinforcing fiber sheet is difficult to stretch when a tensile force is applied in a direction in which the reinforcing fiber yarn extends (longitudinal direction of the reinforcing fiber yarn), and thus the tubular reinforcing fiber sheet as described above is stretched. There is a problem that it is not really easy to expand the diameter. In addition, there is also a problem that the reinforcing fiber sheet does not adhere well to a complicated shape portion such as an uneven portion or a curved portion of the molding die, and wrinkles are generated.
As described above, the reinforcing fiber sheet is required to have not only strength after curing but also high moldability (shapeability) before curing.
Therefore, for example, Patent Document 1 discloses an oriented glass fiber mat in which glass fibers stacked in layers are oriented in one direction and each layer is sewn linearly with a stitch thread in a direction orthogonal to the orientation direction.
Further, in Patent Document 2, a plurality of sheet-shaped members in which a large number of discontinuous fibers are oriented in the same direction are formed, and each sheet-shaped member is laminated so that the arrangement directions of the discontinuous fibers intersect. A multiaxial stitch base material is disclosed which is stitched linearly with a stitch thread to be integrated.
These techniques are mechanisms in which a reinforcing fiber sheet is stretched in the tensile direction by applying tensile force in the orientation direction and shifting each fiber.
Further, Patent Document 3 discloses a repair material for an underground pipe, which is formed into a tubular shape by overlapping both widthwise ends of a sheet material. When pressurized water is supplied into the sewer pipe while it is drawn into the sewer pipe, both widthwise ends of the sheet material slide to shorten the overlap area, which causes the cylinder to expand and expand. It has become.

JP 2003-105663 JP 2009-249784 JP Japanese Patent No. 4288318

However, the techniques disclosed in the above patent documents have the following problems.
That is, in the techniques of Patent Documents 1 and 2, when the reinforcing fiber sheet is stretched, the positions of the respective reinforcing fiber yarns are displaced, so that the density distribution of the reinforcing fiber yarns is not uniform, and the strength after curing varies and the strength decreases. May occur or there may be partial holes in the reinforcing fiber sheet.
Further, the technique of Patent Document 3 has a problem that it is difficult to draw the repair material into the sewer pipe while maintaining the overlapping state, that is, while maintaining the tubular state. Further, if the widthwise both ends of the sheet material are temporarily fixed to maintain the overlapped state, it is possible to smoothly slide the widthwise both ends so that the overlapped portion becomes short when the pressurized water is supplied. There is a problem of difficulty. Further, there is also a problem that the workability is deteriorated because the thickness of only the overlapping portion is almost twice as thick as the other portions.

  In view of such problems, it is an object of the present invention to provide a reinforced fiber sheet that is easily stretchable in one direction, has high shapeability, and can secure high strength after curing.

The reinforcing fiber sheet of the present invention, a large number of reinforcing fiber yarns oriented in one direction becomes one sheet piece by being arranged in a direction orthogonal to the orientation direction, and a plurality of the sheet pieces are continuous in the orientation direction. The plurality of sheet pieces are connected by at least one method of stitching, sewing, tufting, and needle punching, and the sheets are connected at a connecting portion of the sheet pieces when pulled in the orientation direction. It is characterized in that the pieces are displaced in the pulling direction .
Further, it is characterized in that it is formed in a tubular shape such that the orientation direction of the reinforcing fiber yarn is the circumferential direction.
The method for producing a reinforcing fiber sheet of the present invention comprises a step of arranging a large number of reinforcing fiber yarns oriented in one direction in a direction orthogonal to the orientation direction to form one sheet piece, and a plurality of the sheet pieces. A step of continuously connecting in the orientation direction , stitching, sewing, tufting and needle punching is to connect the plurality of sheet pieces by at least one method, and when pulled in the orientation direction, It is characterized in that the sheet pieces are displaced in the pulling direction at the connecting portions of the sheet pieces .
Further, the method is characterized by including a step of forming the reinforcing fiber yarn into a tubular shape so that the orientation direction thereof is the circumferential direction.

When the reinforcing fiber sheet of the present invention is pulled in the orientation direction, the sheet pieces are slightly displaced in the pulling direction at the connecting portions of the sheet pieces, whereby the entire reinforcing fiber sheet can be stretched in the orientation direction. This is because the orientation direction and the tension direction of the reinforcing fiber threads are the same, and for example, two sheets formed by orienting a large number of reinforcing fiber threads 100 in the left-right direction as shown in FIG. 10(a). When the piece 101 is connected by sewing in a state where a part of the piece 101 is vertically overlapped, when the piece 101 is pulled by a force P in the left-right direction (orientation direction) as shown in FIG. This is because it is possible to slightly move the distance d relatively along the side surface.
As described above, in the present invention, when the fiber is pulled, the reinforcing fiber yarn itself does not shift and stretch as in the prior art, but the sheet piece itself shifts at the joining point, so that the reinforcing fiber sheet stretches in the orientation direction. Become.
Therefore, when looking at the reinforced fiber sheet after being stretched, the density distribution of the reinforced fiber yarn is maintained in the same uniform state as before being stretched, so that there is no variation in the strength after curing, and the reinforced fiber sheet has It is possible to prevent the situation where holes are partially opened. In addition, since it is easily stretched in one direction (orientation direction), it is easy to bring it into close contact with the molding die, and the shapeability of the reinforcing fiber sheet can be enhanced.
As a method of connecting the sheet pieces, it is preferable to employ at least one method of stitching, sewing, tufting, and needle punching. These methods have the advantage that they can be implemented at low cost. Further, generally, since the reinforcing fiber sheet is cured by a curable resin or the like, it is not always necessary to firmly connect the sheet pieces to each other, and it is sufficient for practical use that they are fastened by tufting or needle punching. ..
Further, by making the reinforcing fiber sheet into a tubular shape so that the orientation directions of the reinforcing fiber yarns constituting the sheet piece coincide with the circumferential direction, an external force is exerted radially outward from the inside by using pressurized water or the like. In this case, since the reinforcing fiber sheet expands in the circumferential direction and expands in diameter, the reinforcing fiber sheet can be adhered to the inner peripheral surface of various pipes such as sewer pipes and water pipes, making it ideal for repairing and reinforcing various pipes. Become.
When the reinforcing fiber sheet of the present invention is formed into a tubular shape, both ends in the width direction can be fixed by sewing or the like while overlapping or abutting each other. By fixing both ends of the reinforcing fiber sheet in the width direction, it becomes possible to draw the reinforcing fiber sheet into the sewer pipe while maintaining the tubular state. The widthwise ends of the reinforcing fiber sheet in the present invention can be fixed to each other by the characteristic that the reinforcing fiber sheet as a whole stretches in the circumferential direction by slightly shifting the sheet pieces from each other in the pulling direction at the connecting portion of each sheet piece. This is because they have it. In other words, in the present invention, even if both ends in the width direction of the reinforcing fiber sheet are fixed to each other, unlike the technique of the above-mentioned Patent Document 3, a radially outwardly-applied external force such as pressurized water is applied to reinforce the tubular shape. The fiber sheet can be expanded in diameter and expanded. Further, when the widthwise ends are overlapped with each other, a large number of overlapping portions are formed in the circumferential direction, so that the thickness can be made substantially uniform over the entire circumference, and the widthwise ends are abutted with each other. In this case, naturally, the thickness can be made completely uniform over the entire circumference, and the workability can be improved.

A perspective view showing a reinforcing fiber sheet obtained by sewing a plurality of sheet pieces with a stitch thread. A perspective view showing one sheet piece (a) and an actual photograph (b) A perspective view showing one sheet piece (a) and an actual photograph (b) A perspective view showing one surface of one sheet piece (a) and a perspective view showing the other surface (b) Plan views (a1) to (e1) showing examples of sewing lines and plan views (a2) to (e2) showing a state after being stretched. The perspective view which shows the other stitch example of the sheet piece in 2nd Embodiment. A perspective view showing a reinforcing fiber sheet in a third embodiment (a) and a plan view showing a state after stretching (b). FIG. 6 is a vertical cross-sectional view showing the reinforcing fiber sheet according to the fourth embodiment along the orientation direction. The figure showing the state in which the reinforcing fiber sheet in the fifth embodiment is formed in a tubular shape (a), the figure showing the state used for repair and reinforcement of sewer pipes and the like (b) and the figure showing the state after stretching (c) A plan view showing a reinforcing fiber sheet of the present invention (a), a plan view showing a stretched state by pulling (b)

[First Embodiment]
An embodiment of the reinforcing fiber sheet of the present invention will be described.
As shown in FIGS. 1 and 2, the reinforcing fiber sheet 1 has a structure in which a plurality of sheet pieces 10 are continuously connected by stitch threads 20. Note that the sheet piece 10 is schematically shown in FIG. Examples of the method for connecting the sheet pieces include sewing, tufting, needle punching, etc., in addition to stitching, but are not necessarily limited to these.
Specifically, the sheet piece 10 is configured by arranging a plurality of reinforcing fiber threads 11 oriented in one direction in a sheet shape in a direction orthogonal to the orientation direction (hereinafter, simply referred to as “orthogonal direction”). As a means for orienting the reinforcing fiber yarn 11 in one direction, a well-known orienting device may be used, and a description thereof will be omitted.

Further, the reinforcing fibers 11 adjacent to each other in the orthogonal direction are tied with the fastening thread 11a as shown in FIGS. 2(a) and (b), and although not shown, the fastening threads 11a are also on the lower surface side of the sheet piece 10. Tied. As a result, the reinforcing fiber yarns 11 can be prevented from falling apart and can be independently handled as one sheet piece 10.
The size of the sheet piece 10 is not particularly limited, and for example, the length in the orientation direction may be about several tens of centimeters, and the length in the orthogonal direction may be about several tens of meters. Further, the thickness (diameter) of the reinforcing fiber yarn 11 is not particularly limited, and may be adjusted according to the material of the reinforcing fiber yarn 11, the required strength of the sheet piece 10, and the like. Although the cross section of the reinforcing fiber yarn is originally circular, it is generally an elliptical shape that is crushed up and down in the state of being tied with the fastening yarn 11a as shown in FIGS. 2(a) and 2(b).
As the reinforcing fiber sheet of the present invention, as shown in FIGS. 3(a) and 3(b), the reinforcing fiber yarn 11 extending in the orientation direction is not the fastening yarn 11a, but the reinforcing fiber yarn 12 extending in the orthogonal direction or other. It is also possible to use a woven structure that is woven with different types of threads.
As the reinforcing fiber sheet of the present invention, as shown in FIGS. 4(a) and (b), the reinforcing fiber yarns 13 extending in the orthogonal direction are arranged at equal intervals on one surface of the reinforcing fiber yarns 11 extending in the orientation direction. However, a non-crimp fabric structure in which crossing points are tied with fastening threads 14 may be used.
The material of the reinforcing fiber yarn 11 is not particularly limited, and all fibers generally used for a reinforcing fiber sheet can be used. Examples of the reinforcing fiber yarn 11 include carbon fibers, glass fibers, metal fibers such as boron/titanium/steel, synthetic organic fibers such as aramid/polyamide/polyester, and natural organic fibers such as cotton/linen/silk. In addition to the generally known reinforcing fiber thread, for example, an elastic thread made of rubber or an absorbent thread that is absorbed and melted in the living body may be used. Moreover, you may use these various threads individually or in mixture of multiple types.

  As shown in FIG. 1, a plurality of sheet pieces 10 are partially overlapped with each other and are continuously connected along the orientation direction to form a reinforcing fiber sheet. In this embodiment, two sheet pieces 10 are vertically stacked, but three or more may be stacked. The thickness, strength and weight of the reinforcing fiber sheet 1 can be adjusted depending on the thickness of the sheet piece 10 and the number of the sheet pieces 10 stacked.

  The material of the stitch thread 20 is not particularly limited, and examples thereof include synthetic resin threads such as polyester and nylon, and may be appropriately selected in consideration of compatibility with the reinforcing fiber thread 11.

FIG. 5 shows an example of the line L of the stitch thread 20.
Each line L is common in that it extends not in a straight line on the overlapping portion 40 of the sheet piece 10 but in an orthogonal direction while swinging in the orientation direction.
The line La in FIG. 5(a1) swings in a triangular wave shape, the line Lb in FIG. 5(b1) has a trapezoidal wave shape, and the line Lc in FIG. 5(c1) has a rectangular wave shape. The line Ld of 5(d1) has a sawtooth wave shape, and the line Le of FIG. 5(e1) has a smooth sine wave shape. It should be noted that the line L may have a portion where a simple linear shape is mixed (see FIGS. 5(b1) and (c1)), or it may extend in the orthogonal direction while swinging in the alignment direction. However, the shapes are not necessarily limited to the shapes shown in FIGS. 5(a1) to (e1).
FIGS. 5(a2) to (e2) show a state in which the sheet piece 10 has moved by the distance d due to the tensile force P acting in the orientation direction. When the tensile force P acts in the orientation direction, the sheet piece slightly shifts along the position where the line L swings in the orientation direction. As a result, the entire reinforcing fiber sheet 1 can be stretched in the orientation direction.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. However, parts having the same configurations as those of the first embodiment will be assigned the same reference numerals and explanations thereof will be omitted.
As shown in FIG. 6, the present embodiment is characterized in that the line of the stitch thread 20 is a simple straight line. By making the line of the stitch thread 20 straight, the working time for connecting the sheet pieces can be shortened.
Further, when the line of the stitch thread 20 is made straight, the amount by which the sheet piece extends in the orientation direction becomes smaller as compared with the first embodiment, but the length in the orientation direction of the sheet piece is shortened. At the same time, by increasing the number of sheet pieces, it is possible to secure the same amount of elongation as that of the first embodiment as the reinforcing fiber sheet 2 as a whole.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. However, the same reference numerals will be given to the portions having the same configurations as those of the above-mentioned respective embodiments, and the description thereof will be omitted.
As shown in FIG. 7(a), the present embodiment is characterized in that the sheet pieces 10 are connected to each other in a state where the end surfaces of the sheet pieces 10 are abutted with each other without overlapping each other. The back surface side of the reinforcing fiber sheet 3 is backed with felt or the like, and the backing member 30 holds each sheet piece in a horizontal plane.
As shown in FIG. 7(b), the tensile force P acts in the orientation direction, whereby the sheet piece is slightly displaced by the distance d along the position where the line of the stitch yarn 20 swings in the orientation direction. Thereby, the reinforcing fiber sheet 1 can be stretched in the orientation direction.
In the case of the reinforcing fiber sheet 3 of the present embodiment, since the thickness can be suppressed and the thickness can be made uniform, the degree of freedom in bending and deforming can be increased. Further, when the reinforcing fiber sheet is formed into a tubular shape as shown in the fifth embodiment, it is possible to improve the diameter expandability, or to pull one end through the inside of the tube to the other end so that the front and back It is possible to improve workability when reversing.

[Fourth Embodiment]
Next, although a fourth embodiment of the present invention will be described, the same reference numerals will be given to portions having the same configurations as those of the above-described respective embodiments, and the description thereof will be omitted.
As shown in FIG. 8, in the present embodiment, the reinforcing fiber sheet 1 shown in the first embodiment is used as the first layer, and the second layer 31 and further the third layer 32 on the front surface and the back surface thereof. It is characterized in that it has a multi-layered structure provided with the above.
The material of the second layer 31, the third layer 32 and the like is not particularly limited, and examples thereof include a general reinforcing fiber sheet, and a non-woven fabric or mesh sheet containing no reinforcing fiber.
The tensile strength can be increased by using a multilayer structure. Further, even when a tensile force acts in the orthogonal direction, the sheet piece can be prevented from extending in the orthogonal direction.

[Fifth Embodiment]
Next, a description will be given of a fifth embodiment of the present invention, but the portions having the same configurations as those in the above-mentioned respective embodiments are designated by the same reference numerals and the description thereof will be omitted.
As shown in FIG. 9(a), the present embodiment is characterized in that the reinforcing fiber sheet is formed in a tubular shape so that the orientation direction of the reinforcing fiber yarn is the circumferential direction.
The reinforcing fiber sheet 4 is formed into a tubular shape by sewing the widthwise ends together into a sheet shape, and overlapping the widthwise ends of the sheet with each other and sewing them together at the position indicated by reference numeral 4a and fixing them. .. Then, the inner peripheral surface side and the outer peripheral surface side of the reinforcing fiber sheet 4 are impregnated with an uncured synthetic resin in a state of being covered with a film (not shown).
Applications of such a tubular reinforcing fiber sheet include repair and reinforcement of the sewer pipe 50 as shown in FIG. 9(b).
When pressure P (air pressure or water pressure) is applied radially outward from the inside of the reinforcing fiber sheet 4 as shown in FIG. 9(c), the reinforcing fiber sheet 4 is oriented in the orientation direction (the circumferential direction of the tubular reinforcing fiber sheet 4). ), the diameter is increased, and the inner wall surface of the sewer pipe 50 is closely attached. By irradiating light or heat in this state to cure the synthetic resin, it is possible to form the inner surface lining layer having high circumferential strength (pressure resistance, etc.).

The reinforcing fiber sheet of the present invention can be used not only in the fields of civil engineering and construction, but also in various fields such as aerospace, pharmaceutical biotechnology, and craft art.
Further, the inventor of the present application, the plurality of sheet pieces (sheet pieces formed by arranging a large number of reinforcing fiber yarns oriented in one direction in a direction orthogonal to the orientation direction) in a direction orthogonal to the orientation direction. A reinforced fiber sheet continuously connected, or a reinforced fiber sheet in which sheet pieces formed by orienting reinforced fiber yarns in various directions are continuously connected in one direction has been prepared. Then, even when a tensile force is applied to these reinforcing fiber sheets in the direction in which each sheet piece continues, each sheet piece is slightly displaced in the pulling direction at the connecting portion of each sheet piece, whereby the reinforcing fiber sheet is formed. It has been confirmed that the whole stretches slightly in the tensile direction.

  The present invention relates to a reinforced fiber sheet that can be easily stretched in one direction, has high shapeability, and can secure high strength after curing, and has industrial applicability.

1 Reinforcing fiber sheet
2 Reinforcing fiber sheet
3 Reinforcing fiber sheet
4 Reinforcing fiber sheet
4a Fixed point
10 Multiple sheet pieces
11 Reinforcing fiber yarn
11a fastening thread
12 Reinforcing fiber yarn
13 Reinforcing fiber yarn
14 fastening thread
20 stitch threads
30 Backing material
31 Second layer
32 Third layer
40 duplicates
50 sewer pipe

Claims (4)

A large number of reinforcing fiber yarns oriented in one direction become one sheet piece by being arranged in a direction orthogonal to the orientation direction, and a plurality of the sheet pieces are continuously connected in the orientation direction ,
Stitching, sewing, tufting and needle punching is connected to the plurality of sheet pieces by at least one method,
A reinforcing fiber sheet, characterized in that, when pulled in the orientation direction, the sheet pieces are displaced in the pulling direction at the connecting portions of the sheet pieces . 2. The reinforcing fiber sheet according to claim 1, wherein the reinforcing fiber sheet is formed in a tubular shape so that the orientation direction of the reinforcing fiber yarn is the circumferential direction. A large number of reinforcing fiber yarns oriented in one direction are arranged in a direction orthogonal to the orientation direction to form one sheet piece, and a step of continuously connecting the plurality of sheet pieces in the orientation direction. equipped and,
Stitching, sewing, tufting and needle punching is to connect the plurality of sheet pieces by at least one method,
A method for producing a reinforced fiber sheet, characterized in that, when pulled in the orientation direction, the sheet pieces are displaced in the pulling direction at the connecting portions of the sheet pieces . 4. The method for producing a reinforcing fiber sheet according to claim 3, comprising a step of forming the reinforcing fiber yarn into a tubular shape so that the orientation direction of the reinforcing fiber yarn is the circumferential direction.

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