JPH05174650A - Manufacture of insulating spacer made of fiber reinforced plastics - Google Patents

Abstract

PURPOSE:To manufacture an insulating spacer made of a fiber reinforced plastics excellent in electric and dynamic characteristics, with preferable productivity. CONSTITUTION:In manufacturing an insulating spacer used as an insulating flange coupling, which is integrally tightened by a bolt inserted into a communicating bolt hole, a thermoplastic resin is integrally impregnated in a reinforced fiber assembly, thus forming a fiber reinforced resin sheet having a thickness of 2mm or less. The sheet is punched into a predetermined shape including the bolt hole. A plurality of punched sheets are laminated, followed by heating and pressing, thereby obtaining an insulating spacer. The insulating spacer is manufactured by the above processes conducted in order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an insulating flange spacer used in forming a structure requiring insulation. More specifically, the present invention relates to a method for producing an insulating spacer made of a fiber-reinforced resin composite material having a thermoplastic resin as a matrix, which is excellent in electrical properties and mechanical properties with good productivity.

[0002]

2. Description of the Related Art Conventionally, flange joints have been
Although widely used in assembling various structures in terms of strength and flexibility of shape, the material of each component of the joint is generally steel having conductivity in terms of material properties and price.

For this reason, in order to electrically insulate and separate the members to be connected constituting the structure from the flange joint, a spacer inserted between the bolt and the flange is conventionally formed of an insulating material, or insulated. I cover it with a material and use it.

Examples of the insulating material used at this time include rubber, synthetic resin, magnetism, glass and the like.

[0005]

However, the above-mentioned materials conventionally used as insulating materials have some problems. That is, for example, in the case of a relatively soft material such as rubber or synthetic resin, molding is easy, but mechanical properties are inferior, and particularly, low load mechanical properties such as creep are poor. On the other hand, for example, in the case of a relatively hard material such as porcelain and glass, it has good rigidity, but on the other hand, it has poor moldability and is brittle, which causes a problem in handleability.

The insulating spacer, which is the object of the present invention, has a milder mechanical use environment than the insulating member around the bolts, but even if it is a large-sized insulating structure such as an overhead wire structure for supporting electric wires, The above problems are inevitable.

In recent years, with the development of composite materials, attempts have been made to solve such problems by using a fiber reinforced resin, and a thermosetting resin such as epoxy, vinyl ester or unsaturated polyester is reinforced with fibers. Attempts have been made to use the material. This fiber reinforced thermosetting resin has improved low load mechanical properties, which were the drawbacks of conventional synthetic resins,
In addition, it has the advantages that it has better formability than conventional porcelain and is easy to machine.

However, in the case of the fiber-reinforced thermosetting resin, since it takes a long time to cure the resin, the moldability is insufficient, and further improvement in productivity is required. On the other hand, by using a thermoplastic resin,
Although it is expected that the moldability will be greatly improved, since the thermoplastic resin has an extremely high melt viscosity, it is difficult to achieve good integration with the reinforcing fiber, and in a thick molded product such as an insulating spacer. Good performance has not been obtained.

Therefore, the present invention is intended to provide a method of manufacturing an insulating spacer having good performance which can be used for a fastening portion of a large structure using a thermoplastic resin. That is, according to the present invention, bolt holes that are interposed between opposed flanges and can communicate with the bolt holes of both flanges are formed, and the two flanges are fastened to each other by a locking tool such as a bolt inserted in the bolt holes. Which was
Moreover, it is an object of the present invention to provide a method for manufacturing a fiber-reinforced resin insulating spacer formed of a thermoplastic resin containing a reinforcing fiber with good productivity.

[0010]

The manufacturing method of the present invention comprises the following three steps. That is, the first step: impregnating and integrating a thermoplastic resin into a reinforced fiber aggregate to form a fiber-reinforced thermoplastic resin sheet having a thickness of 2 mm or less. Second step: communicating the sheet with a bolt hole of a flange. Punching into a predetermined shape including a bolt hole drilled at a position Third step: After preheating the punched sheets as needed, a plurality of sheets are stacked and heated and pressed to be integrated to obtain an insulating spacer.

In the present invention, the thermoplastic resin sheet formed in the first step is a fiber-reinforced composite material sheet, and its manufacturing method is not particularly limited. For example, a method of placing a powder or film of a thermoplastic resin on a woven or knitted glass fiber, impregnating the woven or knitted resin in a molten state by heating and pressing, a woven fabric in which glass fibers and fibers of a thermoplastic resin are interwoven. It is also possible to employ a method of heating and pressurizing to melt the resin. The fiber content (Vf) is preferably 10 to 80% in volume fraction, more preferably 20 to 70%. If the fiber content exceeds this value, impregnation with the resin becomes difficult and the physical properties of the molded spacer are rather deteriorated, which is not preferable. On the other hand, if the fiber content becomes lower than this value,
It is not preferable because the mechanical properties of the spacer are deteriorated.

The reinforcing fiber used in the present invention is preferably an electrically insulating material, for example, glass fiber, alumina fiber or silica-alumina fiber is used. Among them, glass fiber is preferable. As the form of the reinforcing fiber aggregate, short fibers, mats, woven fabrics, knitted fabrics, unidirectionally aligned stitch materials and the like can be used, and of these, woven fabrics composed of continuous fibers are most preferable. As the woven fabric, satin weave, twill weave, plain weave and roving cloth which are usually commercially available are preferably used.

In the present invention, as the thermoplastic resin to be used, general-purpose engineering plastics such as polycarbonate, nylon, polyacetal and polyester (all of which are insulative) can be used, and among them, polycarbonate and polycarbonate are particularly included. Polymer alloys are preferable from the viewpoints of impregnating property and mechanical properties.

As a method of producing an insulating spacer composed of a thermoplastic resin and a reinforcing fiber, it is conceivable to use a method which is generally used for molding a thermoplastic resin such as injection. In such a method, a woven or knitted fabric is used. It is difficult to manufacture an insulating spacer having excellent mechanical properties using structural reinforcing fibers.

Therefore, in the present invention, the first step of making a sheet (impregnated plate) having a thickness of 2 mm or less by impregnating and integrating a thermoplastic resin into a reinforced fiber assembly, and the sheet having a predetermined bolt hole. From the second step of punching into a shape and the third step of stacking a plurality of punched sheets, preheating if necessary, and then using a mold of a predetermined shape, heating and pressurizing to integrally mold The insulating spacer manufacturing method is adopted.

In the production method of the present invention, in order to impregnate and integrate the thermoplastic resin into the reinforced fiber aggregate, it is usually performed.
Tm (melting point) of the thermoplastic resin used + (20 to 100
℃) and a pressure of 10-200 kg / cm ² are used.
The fiber content (Vf) described above may be adjusted in the third step, but it is preferable to adjust it to a predetermined content at this stage. The thickness of the sheet (impregnated plate) formed in the first step must be 2 mm or less, preferably 1 to 2 mm. If it is thicker than this, the punching property in the second step deteriorates. Further, if the thickness is made too thin, the number of stacked layers in the third step will be complicated, and will be complicated.

The punching machine used in the manufacturing method of the present invention is not particularly limited. The punched shape is preferably matched with the plan view of the final molded product. In the third step of the present invention, the punched sheets (impregnated plates) are laminated to have a predetermined thickness and a fiber content (Vf). At this time, sheets having different fiber contents may be laminated. In either case, adjust so that the bolt holes of each sheet are in the same position when they are overlapped and communicate with each other. This is preferable because post-processing after molding is unnecessary.

Preheating can be carried out as necessary, and generally preheating is preferred. When preheating is performed, the temperature of the glass transition point (Tg) + (50 to 150 ° C.) of the thermoplastic resin is used. When the preheating is sufficiently performed, the mold temperature for stacking and integrating the individual punched sheet plates can be set to the Tg of the thermoplastic resin or less, and the molding at a higher speed becomes possible. .. If the preheating is insufficient or is not performed, the mold temperature is set to T of the thermoplastic resin.
Molding can be suitably carried out by setting the temperature to g + (5 to 100 ° C.). The molding pressure in the third step is preferably 5 kg / cm ² or more. It is preferable to use a mold for molding,
In some cases, molding without a mold can be performed. This molding time may be extremely short, and post processing such as drilling of bolt holes is unnecessary.

[0019]

EXAMPLES Hereinafter, the production method of the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

[0020]

Example 1 Polycarbonate having a Tg of 145 ° C. (Teijin Kasei Co., Ltd., trade name “Panlite”) as a thermoplastic resin and glass fiber plain weave cloth (Unitika Co., Ltd., roving cloth) are laminated as reinforcing fibers. Then, using a hot press, temperature 295 ℃, surface pressure 40kg
By heating and pressurizing under the condition of f / cm ² , Vf46
%, A glass fiber reinforced resin sheet having a thickness of 1.3 mm and impregnated and integrated with polycarbonate was obtained.

The sheet thus obtained was punched into a predetermined size having a 30 mm diameter bolt hole in the center using a clicker press, and 15 of the punched sheets were punched out.
The sheet was put into a mold of a predetermined size. Then, after preheating at 240 ° C. for 10 minutes, the individual punched sheets were integrated by pressurizing under a pressure of 75 kgf / cm ² , and demolded at 120 ° C. or lower.

The glass fiber reinforced resin structure thus obtained has a Vf of 50%, a specific gravity of 1.86 and a thickness of 18 mm,
It was an insulating spacer used for insulating flange joints with excellent mechanical properties.

[0023]

According to the manufacturing method of the present invention, all of the above three steps can be carried out in a short time, and the productivity is remarkably improved as compared with the conventional method using a thermosetting resin as the matrix resin. To do. Moreover, since a woven or knitted structure can be used as the reinforcing fiber aggregate, an insulating spacer having excellent mechanical properties can be obtained. Furthermore, since a thermoplastic resin is used, it is possible to recover and reuse the resin from the used and discarded one.

Claims (6)

[Claims] 1. An insulating spacer used for an insulating flange joint, which is for manufacturing a spacer which is interposed between a pair of flanges and which is fastened to both flanges by a locking tool inserted into a communicating bolt hole. In the first step, the thermoplastic resin is impregnated and integrated with the reinforced fiber aggregate to form a fiber-reinforced thermoplastic resin sheet having a thickness of 2 mm or less, and the second step of punching the sheet into a predetermined shape including bolt holes. And a third step of stacking a plurality of punched sheets, heating and pressurizing them to obtain an insulating spacer, and a third step. 2. The method for producing an insulating spacer according to claim 1, wherein the reinforcing fiber aggregate is a woven or knitted glass fiber. 3. The method for producing an insulating spacer according to claim 1, wherein the thermoplastic resin is polycarbonate or a mixture thereof. 4. The method for producing an insulating spacer according to claim 1, wherein the volume content of the reinforcing fibers in the fiber-reinforced thermoplastic resin is 10 to 80%. 5. When laminating punched sheets, the glass transition point (Tg) of the thermoplastic resin + (50 to 150 ° C.)
The method for producing an insulating spacer according to claim 1, wherein the method is preheated to the temperature. 6. The insulating spacer according to claim 1, wherein the punched sheet is integrated by pressing at a temperature of glass transition point (Tg) + (5 to 100 ° C.) of the thermoplastic resin. Manufacturing method.