JPH06201072A - Fiber-reinforced synthetic resin pipe - Google Patents

Abstract

PURPOSE:To improve the retainability of resin and enable the formation of a pipe wall without a pin hole and a crack by using an unwoven fabric compound mat with circumferential and axial reinforcing yarn and unwoven fabric formed integrally in a fiber-reinforced synthetic resin pipe. CONSTITUTION:In this fiber-reinforced synthetic resin pipe, a continuous strand mat 1 as an outer layer, pipe circumferential glass roving 2, 4 and pipe axial glass roving 3 as an intermediate layer, and an unwoven fabric compound mat 5 as an inner layer are used as reinforcing fiber. the material used as the unwoven fabric compound mat 5 is obtained by forming pipe circumferential and axial reinforcing yarn, that is, longitudinal and lateral reinforcing yarn 6, 7, integrally with unwoven fabric 8 through twining yarn 9, and thermoplastic resin is used as the material of the reinforcing yarn 6, 7 and unwoven fabric 8. Such an unwoven compound mat 5 is also formed being wound at least by one layer into pipe shape so as to be provided in such a way as to form the continuous layer of the unwoven compound mat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced synthetic resin tube having good airtightness.

[0002]

2. Description of the Related Art A fiber-reinforced synthetic resin tube obtained by impregnating an uncured resin into a reinforcing fiber and curing the resin is used as a structural material for a protective tube of a power cable, a handrail, a pillar of a fence, and the like. Since the bending strength, tensile strength, and compressive strength of the pipe are required for these applications, the reinforcing fiber is composed of a continuous strand mat on the surface layer and continuous fibers such as glass roving in the axial and circumferential directions. Has been done.

[0003]

In the prior art, when the inside of the fiber-reinforced synthetic resin tube after curing is filled with a liquid and pressurized, a tear leak phenomenon occurs before the rupture due to water pressure occurs, and more. There was a drawback that the pressure did not rise. This is often caused by pinholes present in the surface mat layer or resin cracks present between fibers inside the cross section. It is considered that the pinhole is generated because the resin component falls off before curing or the resin component is insufficient from the beginning. Also, the cracks that exist between the fibers,
Since the resin has a property of shrinking during curing, it is considered that the resin is generated by the force at that time.

Among these disadvantages, in order to eliminate cracks between fibers, a resin having a very small curing shrinkage has been used in the past, or a non-woven fabric having a good resin retention property and a surface mat in order to eliminate pinholes in the surface layer. Is being used. However, non-woven fabric with good resin retention,
Surface mats etc. are easily cut by operations such as resin impregnation, elongation is remarkable due to the tension during molding, the width becomes narrow, and as a result the surface layer can not be covered seamlessly, so the tear leakage phenomenon occurs. It could not be suppressed sufficiently.

[0005]

The present invention has been made to solve the above-mentioned problems, and is characterized by using a nonwoven fabric composite mat in which reinforcing yarns in the circumferential and axial directions and a nonwoven fabric are integrally formed. The present invention provides a fiber-reinforced synthetic resin tube.

[0006]

A typical example of the fiber-reinforced synthetic resin pipe of the present invention will be described with reference to the schematic partial sectional view in the circumferential direction of the pipe shown in FIG. Outer layer continuous strand mat 1 and middle layer tube circumferential direction glass roving 2, 4 and tube axis direction glass roving 3
It is an example in which the fiber for reinforcing the tube is formed from the non-woven fabric composite mat 5 of the inner layer. The non-woven fabric composite mat 5 can be arranged not only in the inner layer but also in the middle layer or the outer layer together with the inner layer. In addition, two or more layers can be stacked and used by arranging the tube so that it is wound two or more times in the circumferential direction.
The nonwoven fabric composite mat wound in the circumferential direction of the tube in order to secure the airtightness of the tube by suppressing the tear leakage phenomenon of the tube preferably has a structure in which both terminals in the circumferential direction overlap each other.

The non-woven fabric composite mat according to the present invention is one in which reinforcing yarns in the circumferential and axial directions of the tube and the non-woven fabric are integrally formed, and typical examples thereof are shown in FIGS. FIG. 2 is a schematic plan view of the nonwoven fabric composite mat, and FIGS. 3 and 4 are schematic cross-sectional views in the mat thickness direction. The longitudinal reinforcing yarns 6 and the transverse reinforcing yarns 7 correspond to the circumferential or axial reinforcing yarns of the pipe, respectively. These reinforcing yarns are knots 9
The non-woven fabric 8 and the reinforcing yarns 6 and 7 can also be integrated via the interlacing yarn 9.
As shown in FIG. 4, it is preferable that the nonwoven fabric 8 and the reinforcing yarns 6 and 7 are integrated with each other by inserting the knotting yarn 9 through the nonwoven fabric 8. The reinforcement threads may be integrated with each other or the reinforcement threads may be integrated with the non-woven fabric by bonding with a thermosetting resin, but the integration with a female thread is preferable since the resin impregnation property and strength during molding are excellent.

It is preferable that the longitudinal and lateral reinforcing yarns are arranged at an interval of 1 to 10 mm.
If it is too wide, the unevenness of the surface of the non-woven fabric composite mat becomes large and the appearance of the molded tube is impaired, which is not preferable. The basis weight of the non-woven fabric is in the range of 15 to 500 g / m ² , and the thickness of the reinforcing thread is 1
The range of 000 to 5000 denier and the thickness of the knitting yarn are preferably 75 to 1000 denier. The non-woven fabric is
Since the resin retainability and the adhesiveness to other reinforcing fibers are good, it is preferable that the filament is made of a finer thermoplastic resin filament.

The material of the reinforcing yarn, entangled yarn or non-woven fabric of the non-woven composite mat may be an inorganic material such as glass, carbon or ceramics, but is excellent in tensile strength and required strength against the temperature at the time of curing the impregnated resin. A thermoplastic resin such as a polyester resin, a polyamide resin, a polypropylene resin, or an aramid resin having a resin is preferable.

In addition to the above-mentioned nonwoven fabric composite mat 5, the fiber reinforced synthetic resin tube of the present invention has the glass rovings 2, 3, 4 shown in FIG. 1 for the purpose of improving the bending strength and compressive strength of the tube.
It is preferable to arrange continuous fibers such as In FIG. 1, glass rovings 2 and 4 are wound in the circumferential direction of the tube, and glass roving 3 is used in the axial direction of the tube. It is preferable to dispose a continuous strand mat 1 on the outer layer of the tube in order to suppress pinholes.

The material of the above continuous fiber or continuous strand mat is preferably glass, and may be carbon, ceramics or aramid resin. A thermosetting resin such as an unsaturated polyester resin, an epoxy resin, or a phenol resin is preferably adopted as the resin with which the reinforcing fiber is impregnated. If necessary, a filler such as calcium carbonate or aluminum hydroxide and a curing initiator such as an organic peroxide are mixed in the resin.

As a method for molding the fiber-reinforced synthetic resin pipe of the present invention, a pultrusion molding method capable of continuous molding is preferably adopted. In this pultrusion method, reinforcing fibers such as non-woven resin composite mat and glass roving impregnated with uncured resin are continuously introduced from the other end of the heating mold while being introduced from one end of the heating mold and cured in the heating mold. By doing so, a molded product is obtained.

As a method of impregnating the uncured resin into the reinforcing fiber, a method of immersing the reinforcing fiber in an uncured resin tank or a method of press-fitting the uncured resin near the inlet of the heating mold is preferably adopted.

The fiber-reinforced synthetic resin pipe of the present invention is preferably used in various applications where the airtightness of the pipe is required, and in particular, a heating medium liquid transport pipe, a chemical liquid transport pipe or a covering pipe such as a cable-stayed bridge cable is used. Can be mentioned.

[0015]

[Example] As a glass fiber, a continuous strand mat of 450 g / m ² was placed on the outer layer, and a glass roving for circumferential strengthening was wound on the inner side of the mat, and a predetermined number of glass was placed on the inner intermediate layer. The rovings were axially aligned and inserted. Further, glass roving was wound around the inner layer side, and a 300 g / m ² non-woven fabric composite mat was wound around the innermost layer twice. When the composite mat was wound, the ends in the circumferential direction were overlapped by 30 mm.

The composite mat is made of polyester non-woven fabric with 450
0 denier polyester reinforcement yarn is arranged in a grid pattern with a pitch of 10 mm, and this is denier with 250 denier yarn 5
The one entwined with the mm pitch was used.

An internal diameter of 20
A tube with a thickness of 0 mm and a wall thickness of 6 mm was obtained. This tube was able to be wound around the innermost layer of the tube without stretching or breakage of the composite mat, and the composite mats could also be formed with sufficient lap allowance.

When both ends of this pipe were sealed and subjected to a water pressure test, water leakage occurred at a water pressure of 25 kgf / cm ² and 35
The water pressure increased to kgf / cm ² . On the other hand, in a tube using a continuous strand mat of 450 g / m ² instead of this composite mat, water seeped out from the water pressure of 10 kgf / cm ^2, and the water pressure could not rise above 20 kgf / cm ² . Further, when a test piece was cut out from these tubes and subjected to a Charpy impact test, it was confirmed that the impact value was improved by 30% when the composite mat was used.

[0019]

According to the present invention, by adopting the above-mentioned constitution, the resin retaining property is improved, the tube wall without pinholes or cracks can be formed, and the tube can be made airtight. In particular, when the non-woven fabric composite mat according to the present invention is used for pultrusion to form a tube, the above effect becomes more certain.

That is, since the non-woven fabric composite mat is reinforced with the reinforcing yarn, even after the resin is impregnated in the pultrusion process, the breakage and the elongation are suppressed. The greatest feature is that it can be wound.

[0021] Also, while keeping the advantages of the non-woven fabric,
Since the fiber-reinforced synthetic resin pipe of the present invention has excellent airtightness because it can be pultruded, when it is used for transporting a chemical liquid, by using a nonwoven fabric composite mat for the inner layer, the pultruded pipe The drawback of insufficient corrosion resistance, which was the drawback of item (1), can be greatly improved.

Furthermore, when a non-woven fabric composite mat made of fine organic fibers is used, it has the advantage that it is difficult to be cut, it is possible to prevent it from being torn off by an external impact, and it is also effective in preventing scattering. .

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional view in the circumferential direction of a fiber reinforced synthetic resin pipe which is one specific example of the present invention.

FIG. 2 is a schematic plan view of a non-woven fabric composite mat constituting a fiber-reinforced synthetic resin pipe which is one specific example of the present invention.

3 is a schematic cross-sectional view of the nonwoven fabric composite mat of FIG.

FIG. 4 is a diagram for explaining the position of the entanglement yarn in the nonwoven fabric composite mat of FIG.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Koshiro Hayashi 1-2-2 Miyashita, Sagamihara-shi, Kanagawa Asahi Glass Matex Co., Ltd. (72) Inventor Koji Inoue 2-2-1 Nihombashi Muromachi, Chuo-ku, Tokyo Inside Toray Co., Ltd. (72) Inventor Sumio Asai 340 Oshimizu, Oshimizu-cho, Toyohashi City, Aichi Prefecture Toyohashi Asai Weaving Co., Ltd. (72) Inventor Yutaka Honda, 2-4 Kawamachi, Chuo-ku, Osaka City, Osaka Chori Co., Ltd.

Claims (6)

[Claims] 1. A fiber-reinforced synthetic resin pipe comprising a non-woven fabric composite mat in which reinforcing yarns in the circumferential and axial directions are integrally formed with a non-woven fabric. 2. The fiber-reinforced synthetic resin pipe according to claim 1, wherein in the non-woven fabric composite mat, the reinforcing yarns in the circumferential direction and the axial direction and the non-woven fabric are integrally formed through the interlocking yarns. 3. The fiber-reinforced synthetic resin pipe according to claim 1, wherein the continuous layer of the non-woven composite mat is formed by winding at least one layer of the non-woven composite mat into a tubular shape. 4. The fiber-reinforced synthetic resin pipe according to claim 1, wherein a continuous strand mat and a glass roving are used together with the non-woven composite mat. 5. The fiber-reinforced synthetic resin pipe according to claim 1, wherein the material of the reinforcing yarn and the nonwoven fabric in the circumferential and axial directions is a thermoplastic resin. 6. The fiber-reinforced synthetic resin pipe according to claim 1, which is obtained by a pultrusion method.