JPH01250427A - Fiber material for reinforcing resin - Google Patents

Abstract

PURPOSE:To obtain the title fiber material providing FRP having smooth surface and high strength free from ply separation, comprising a mat wherein filaments bundled materials are opened, parts put in order in the longer direction and parts swollen in the perpendicular direction are entangled at interwined parts. CONSTITUTION:A ribbon-like material 1 obtained by opening a great number of filament bundled materials is used, interwined parts 2 are formed by entangling the filaments constituting the ribbon-like material 1 at positions at intervals and the ribbon-like material 1 is divided into plural sections 3. Each section consists of first group filaments f1 and f1' wherein the ribbon-like material is put in order in the longer direction and second group filaments f2 and f2' wherein the ribbon-like material is swollen in the perpendicular to the longer direction and each filament is made to have equal whole length in such a way that a filament belonging to the first group in one section belongs to the second group in another section. The aimed fiber material consists of a mat comprising woven fabric obtained by using the ribbon-like material as warp or weft, the ribbon-like material or a cut material thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin reinforcing fiber body used for manufacturing an IR male reinforced resin body (FRP).

[Prior Art] FRP is manufactured by impregnating a reinforcing pot body with a liquid thermosetting resin and curing the resin, and is widely used for hastuffs, automobile bodies, bumpers, and the like.

FRP manufacturing methods include press molding method, resin injection method (RI method), Hunt lay-up method (HL method)
etc. are known.

In order to obtain FRP with high strength and heat resistance, it is necessary to use reinforcing fibers with high strength and heat resistance. Inorganic fibers such as glass fibers and alumina fibers are suitable fibers for this purpose, and among these, glass fibers are the most widely used.

Such fibers are often used in the form of a fiber bundle (strand) in which a large number of long monofilaments are aligned and bundled, preferably with the addition of a binding agent.

It can be obtained by randomly depositing long strands in a curved shape on a moving conveyor, or by randomly depositing cut strands, and adding a binder to bind the strands together. Mats such as continuous strand mats (CSM) and chopped strand mats (CCM) are widely used as resin reinforcing fibers for FRP.

Alternatively, woven fabrics using strands or rovings thereof are also widely used as tag bodies for resin reinforcement of FRP.

[Problems to be Solved by the Invention] Since the mat or fabric using the aforementioned strands or rovings has a large number of monofilaments bundled together, it has a large bulk density, and when the weight per unit area is constant, its In order to obtain FRP with a small thickness and a large thickness, it is necessary to use a large number of stacked mats or fabrics, or the obtained FRP is peeled off along the interface between stacked mats or fabrics. There are some easy and difficult points.

In addition, when these mats or fabrics are impregnated with liquid resin, the resin is difficult to penetrate into the strands, causing F.
Poor resin impregnation tends to occur in RP, and in the case of deep drawing molding, there are problems in that mold conformability is insufficient.

The object of the present invention is to obtain a resin-reinforcing fiber body that has a low bulk density, a large thickness, good resin impregnation properties, does not cause delamination of FRP, and has good mold conformability.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, the resin reinforcing fiber body used for manufacturing the woven reinforcement resin body is a string-like body obtained by removing a bundle of a large number of filaments. A tangled part in which the filaments constituting the string-like body are intertwined is formed at a spaced apart part of the string-like body, and the string-like body is divided into a plurality of sections by this entangled part, and each section is divided into two sections. The string-like body includes a first group of filaments aligned in the longitudinal direction of the string-like body and a second group of filaments that are unraveled and expanded in a direction perpendicular to the longitudinal direction, and constitute a string-like body. In order to make the total length of each filament equal, in one section, the filament belonging to the first group filament is used, and in another section, the string-like body belonging to the second group filament is used at least as the weft or warp, or the above-mentioned string-like body A mat (generally referred to as the resin reinforcing fiber body) made up of the cut material is constructed.

Next, the present invention will be explained in more detail.

FIG. 1 is an enlarged plan view for schematically explaining the structure of a string-like body 1 used in the present invention. A tangled part 2 in which the filaments constituting the string-like body 1 are entangled is formed at a spaced apart part of the body 1, and this tangled part 2
The string-like body 1 is divided into a plurality of sections 3, and each section 3
The string-like body 1 includes a first group of filaments f aligned in the longitudinal direction of the string-like body 1, and a first group of filaments f2 that are unraveled and expanded in a direction perpendicular to the longitudinal direction. The filaments belonging to the first group of filaments in certain sections are made to belong to the second group of filaments in other sections so that the total lengths of the filaments constituting the string-like body are equal.

The filaments that should constitute the string-like body (simply referred to as a string-like body) include inorganic fibers such as glass fiber, alumina flim, silica fiber, zirconia m-fiber, and titania fiber, organic fibers such as Kevlar m-fiber, It is preferable to use metal fibers such as brass fibers, carbon fibers, or composite fibers made by blending these fibers, or to use glass fibers or composite fibers mainly composed of glass fibers.

The thickness of the fibers may be 3 to 30 mm, preferably 5 to 25 mm, and a sizing agent may be added to these fibers to reduce the thickness to 50 mm to 25 mm.
Bulking conditions are selected, such as arranging 100,000 fibers, preferably 200 to 50,000 fibers, to form a fiber bundle, and bulking such a fiber bundle while increasing the feeding speed to the bulking device. In this way, the string-like body of the present invention can be made using a bulking device equipped with a tubular passage having a high-pressure gas supply hole.

As the sizing agent, it is preferable to use a material with low adhesive strength such as epoxy resin, and the amount added is 0.1-lowt% as solid content, preferably 0.2-5wt%.
It is appropriate to say.

In the string-like body l, tangled portions 2, 2, . . . are formed in which the filaments constituting the string-like body are intertwined at locations separated by predetermined intervals in the longitudinal direction.

In the tangled portion 2, the filaments are intertwined in the form of a braid in the form of a monofilament or in a state in which a plurality of filaments are aligned, and due to this intertwining, the filaments are slightly twisted.

By forming this entangled portion 2, the filaments constituting the string-like body 1 are bonded together so as not to be separated from each other.

It is appropriate that the distance between h@the twisted part 2 and the entangled part 2 be 1 to 30 mm, preferably 3 to 15 mm. If this length is too small, the ratio of the entangled portion 2 to the total length of the string will be large, resulting in poor bulkiness of the string 1, the thickness of the reinforcing fiber, and the impregnability of the resin. . Moreover, if this length is too large, the filaments of the first group and the filaments of the second group tend to separate.

The length of the entangled portion 2 is 0.1 to 5 mm, preferably 0.1 to 5 mm.
It is appropriate to set it to 2 to 3 mm. If this length is too large, the bulkiness of the string-like body 1 will be poor, and if this length is too small, the filaments constituting the string-like body 1 will easily separate.

The string-like body 1 is divided into a plurality of sections 3, 3, . . . by the entangled portions 2. In the section divided and partitioned by the entangled portion 2, the string-like body 1 has a first group of filaments f aligned in the longitudinal direction of the string-like body and preferably twisted.
□ and a second group of filaments f2 that are preferably opened into a monofilament shape and swell in a direction perpendicular to the longitudinal direction. The filaments belonging to the second group are unraveled and the axis that connects the tangled parts (the longitudinal direction of the string-like body)
It swells outward in a substantially arc shape and is preferably fibrillated into a monofilament. Note that the direction of this bulge is not limited to a specific plane including the axis, but is random.
When viewed macroscopically (on average), the string-like body has a substantially round cross section. The maximum distance of this bulge from the axis is 2 to 10
It is appropriate to set it to about mo.

The filaments belonging to the first group are aligned in the longitudinal direction. The filaments are preferably twisted in the S direction or the Z direction, and this twist improves the integrity of the filaments belonging to the first group.

When focusing on a specific section, the length of the filament f1 belonging to the first group is shorter than the length of the filament f2 belonging to the second group, and when tension is applied to the string-like body, the filament f1 belonging to the first group antagonize.

The filament f2 belonging to the second group is longer than the filament f belonging to the first group, which is longer and swells outward from the longitudinal direction and does not itself counteract the tension; , and entangled part 2
The tension applied to the string body 1 is absorbed by the filament f1 belonging to the first group, so even if tension is applied to the string body 1, the length of this section is the same as that of the filament f1 belonging to the first group. The filaments f2 belonging to the second group are not stretched substantially beyond the length of f1 and lose their bulkiness.

It is appropriate that the number of filaments belonging to the first group is 10 to 50% of the total number of filaments.

If this number is too large, the bulkiness of the string-like body 1 will be poor, and if this number is too small, the strength in the longitudinal direction of the string-like body 1 will tend to decrease.

When focusing on a particular section, the filament f1, indicated by a broken line belonging to the first group, and the filament f2, indicated by a solid line belonging to the second group, intertwine and intermingle at the tangled portion at the end of this section. In the next section, the filament f1' belongs to the first group and the filament f2' belongs to the second group.

At this time, at least a part of f shifts to f2' and belongs to the second group, and at least a part of f2 shifts to h'' and belongs to the first group. Such a transition to a different group (Change of affiliation) is done randomly, or when focusing on a certain filament, the number of times this filament belongs to the first group in each section is almost equal to the number of times it belongs to the second group, forming a string-like body. The total length of each filament ← becomes equal.

Note that the direction of twist given to the filaments of the first group is reversed in some places, and the number of twists in the S direction and the number of twists in the Z direction are approximately equal to each other in the string-like body as a whole, causing twisting in the string-like body. Never.

A reversal of the twist direction may also occur within a section, in which case a small length of untwisted portion may occur in this reversal.

Note that the filaments belonging to the first group may swell slightly outward at such inverted portions, but this swell is extremely small compared to the swell of the filaments of the second group, and the above-mentioned string-like It does not affect the countervailing force to the tension applied to the body.

In addition, the length of the tangled part, the distance between the tangled parts, the number of filaments belonging to the first group in each section, the degree of swelling of the filaments belonging to the second group, etc. are set to constant values over the entire length of the string-like body. It is practically meaningless to control these values within the above-mentioned ranges, and the object of the present invention can be fully achieved.

Furthermore, the string-like body can be made of relatively soft fibers such as glass uA or organic fibers, or it can be made of brittle fibers such as silica fiber, and such a string-like body can provide tension. It does not lose its bulkiness even when exposed to heat, and has great heat resistance.

In the present invention, the reinforcing fiber body is a woven fabric using a string-like body (
Consists of a mat (real fabric) or a mat (real mat).

Since the string-like body does not stretch even when tension is applied and does not lose its bulky properties, the present woven fabric can be manufactured using the string-like body by a conventional method.

Note that although the present woven fabric can be constructed of string-like bodies for both the weft and the warp, it is also possible to use a string-like body for only one of them (preferably only the weft). Furthermore, a non-woven fabric in which the weft and warp yarns are bonded together can also be used as the main fabric.

As mentioned above, the string-like body has a nearly round cross section, and when the weight per unit area is constant, the thickness of this fabric is about three times that of a fabric using ordinary strands or roving. In addition, since the fibers are defibrated, impregnation with liquid resin is good.

This performance is comparable to woven fabrics using spun yarn, yet the manufacturing effort is much less than that of spun yarn, and this woven fabric is composed of much longer fibers than spun yarn. ,
By using this fabric for reinforcing FRP, it is possible to obtain FRP with greater strength than when using spun yarn fabric.

Using a continuous string-like body or a string-like body cut into a predetermined length (25 mm or more, preferably 50 mm or more), these are dropped and deposited on a moving conveyor according to a conventional method, and the binder is added. This mat can be obtained by adding .

The amount of deposition is 50 to 5,000 gr/rn', preferably 100 to 3,000 gr/rn', and is approximately 5 times thicker than normal CS or CSM with the same amount of deposition. A mat with good resin impregnation properties can be obtained. Also, since this mat is composed of continuous filaments,
By using this mat, it is possible to obtain a homogeneous FRP that has strength comparable to that of conventional CM and CSM.

In addition, since the string-like body is defibrated and has a second group of filaments that bulge in a direction perpendicular to the longitudinal direction, the string-like bodies become intertwined with each other, so the amount of binder used is reduced compared to normal CM and CSM. FRP due to binder has decreased to about 50%.
It is possible to minimize the deterioration in quality.

Furthermore, since the string-like body constituting the wood mat or real fabric contains a second group of filaments that are unraveled and bulge in a direction perpendicular to the longitudinal direction, it is possible to stack multiple pieces of this fabric or real mat. When used for reinforcing FRP, since the filaments of this second group are intertwined, the FRP does not peel off, and it is possible to obtain FRP with a smooth surface, and it conforms well to the mold.

A thermosetting resin such as an unsaturated polyester resin or an epoxy resin is added to the fiber body for reinforcing the resin of the present invention, and the amount of resin in the FRP is 4.
FRP can be obtained by impregnating it to a concentration of about 0 to 80 wt % and using a press molding method, RI method, HL method, etc. The type of resin used and the molding method are the same as conventional methods, so a detailed explanation will be omitted.

[Function] A string-like body obtained by unraveling a bundle of a large number of filaments, in which tangled portions are formed where the filaments constituting the string-like body are intertwined at spaces apart from each other. The string-like body is divided into a plurality of sections by this entangled portion, and in each section, the string-like body is divided into a first group of filaments that are aligned in the direction of the pitcher's force, and a first group of filaments that are unraveled and aligned in the direction of the pitcher's force. A filament that belongs to the first group filament in a certain section belongs to the second group filament in another section so that the total length of each filament constituting the string-like body is equal. By constructing a fabric or mat using a string-like body characterized by This ensures good conformability to the mold and prevents delamination.

[Example 1] A fiber bundle made by adding 0.2 wt% of epoxy sizing agent as a solid content to glass fibers A (filament) having a diameter of 9 mm and converging 4,000 fibers was used to meet the following specifications. A string-like body was manufactured.

The average length of the tangled parts is 3 mm, the average ratio between the tangled parts is #8■, and the average number of filaments belonging to the first group is 1,50.
0, the degree of swelling of the filaments belonging to the second group (average thickness of the string-like body) was 5 mm.

This string-like body is dropped onto a moving conveyor at a rate of 450g/m', deposited in a curved shape, and 1.5wt% of saturated polyester resin powder is added as a binder and heated. The string-like bodies were combined to form a mat.

This mat was about 5 times thicker than a normal mat of the same specifications, and the required amount of binder could be reduced to about 50%.

This mat is well impregnated with liquid thermosetting resin and conforms well to the mold. By using this mat as a reinforcing fiber, it has a strong and smooth surface, and it can be used to make FRP that does not peel off easily. I was able to wander using the layup method.

Note that unsaturated polyester was used as the resin.

Further, the amount of resin used was 70 wt% in FRP.

[Example 2] A woven fabric having the following specifications was obtained using the same string-like bodies as in Example 1 as the warp and weft.

Number of threads: Warp: 12 threads/25mm weft
Thread 5.5/25mmrn
'Extruded weight 1,500 gr Thickness 3.5 mm
The same results as in Example 1 were obtained using this fabric.

[Effects of the invention] By using this resin reinforcing m-fiber body, the thickness is increased,
It is possible to obtain FRP with a smooth surface and high strength without causing peeling.

[Brief explanation of the drawing]

FIG. 1 is an enlarged plan view for schematically explaining the structure of a string-like body used in the present invention. In the figure, 1 is a string-like body, 2 is a tangled part, 3 is a section, fl+f, -
is the first group filament, f2. f2' indicates the second group of filaments.

Claims (1)

[Claims] (1) A reinforcing fiber body used in manufacturing a fiber-reinforced resin body by impregnating a liquid thermosetting resin and curing the resin, which is a string-like body obtained by defibrating a bundle of many filaments. Then, a tangled part in which the filaments constituting the string-like body are intertwined is formed at a spaced apart part of the string-like body. The shaped body includes a first group of filaments arranged in the longitudinal direction of the string-like body and a second group of filaments that are opened and expanded in a direction perpendicular to the longitudinal direction. A woven fabric in which filaments belonging to the first group of filaments in one section and strings belonging to the second group of filaments in other sections are used as at least the weft or warp so that the total length of the filaments is equal, or the above strings or their cutting. A fibrous body for resin reinforcement, characterized in that it consists of a mat made up of a material.