JPS635845B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an electrical insulator for low voltage, high voltage and very high voltage made from resin-bonded glass fibers, which is made of ethylene-propylene having high physical properties, especially dielectric properties. The present invention relates to an insulator having a rib coating prepared from an elastomer and a method of manufacturing the same.

Electrical insulators made of resin-bonded glass fibers with a rib coating made of organic materials are already known and are widely used in the field of outdoor low-voltage and high-voltage overhead lines and in the field of electrical operation. . Thus, the main advantage of this insulator made of resin-bonded glass fibers and organic materials over conventional porcelain or glass insulators lies in a particularly low "weight/mechanical strength" ratio.

In fact, when conventional porcelain or glass insulators in the form of pins and caps are intended for outdoor high-voltage and very high-voltage overhead lines with high mechanical loads due to ropes, it is necessary to use metal caps of large dimensions. The weight of the entire insulator chain is therefore no longer negligible with respect to the weight of the conductors supported by the chain.

In composite types of insulation made from resin-bonded glass fibers and organic materials, the mechanical support function is entrusted solely to the resin-bonded glass fiber rod shape or central body. This center body is generally used when the glass fibers are arranged in filaments parallel to each other and parallel to the direction of the mechanical stress to which the supporting center body is subjected during operation, or when the glass fibers are cut into felts, i.e. cut into pieces. When using chopped glass fibers (chopped strands) or glass fiber fabrics, "pulltrusion" (=
In the case of continuous fibers, which are usually arranged in a spiral manner, they are produced in the form of hollow cylinders according to the filament winding method. Glass fiber fabrics are also used to produce the product (or central body) in the form of this hollow cylinder or cylinder. Therefore, whether it is a solid bar or a hollow cylinder, the glass fiber is
A resin with the best electrical properties (eg a cycloaliphatic epoxy resin) is impregnated.

The central body exhibits approximately the same mechanical strength as steel, but with a specific gravity equal to approximately 1/2 that of steel.

In the case of electric railways and cableways, resin-bonded glass fiber insulation offers considerable advantages compared to conventional porcelain insulation. Because, in this field of technology, it is of utmost importance that the insulation can successfully withstand the strong vibrations experienced during the work, and it is important that the insulation is made of resin-bonded glass fibers, which is different from the porcelain version. This is because it can be easily achieved.

However, several significant obstacles have been encountered in producing resin-bonded fiberglass insulation that is fully satisfactory in all respects. First, a suitable material for preparing the largely ribbed coating of the insulator, one that resists both the effects of aging and surface discharge. Surface discharges (including undesired tracking and/or erosion phenomena) have been extremely difficult to detect.

Also, suitable materials [e.g., alicyclic epoxy resin, silicone elastomer, ethylene-propylene elastomer, fluorinated resin (PTFE), etc.]
Even once the requisite conditions of aging resistance and surface discharge resistance are achieved with the aid of a material, the problem of coupling the resin-bonded fiberglass center body (solid bar or hollow cylinder) with the rib coating material remains. The issue remains unresolved.

In fact, the physical properties, especially the mechanical properties, of resin-bonded glass fiber bodies are such that they cannot be reliably coupled to materials that react with inelastic behavior that results in deformation due to mechanical stress.

As a result, various coupling methods have been investigated in an attempt to eliminate such drawbacks. The method may include coupling with an elastomeric resin or silicone grease or rubber mastic, or may include coupling the rib coating material to the resin-bonded glass fiber body solely by physical forcing.

However, none of the above methods could satisfactorily solve the above problem. In other words, it has been found that, in practice, all of these methods result in weak points of the insulator from an electrical point of view.

In practice, it should be noted that the external shape of low voltage, high voltage and especially very high voltage insulators, where the ribs have a considerable width and thickness, can be used between the metal terminals of the insulator (if any). Discharges (between live conductor and earth), i.e. as long as possible, and particularly high surface creep lines (
creeping line) has been studied for the opposite purpose.

"Surface creep line" means the ( Therefore, it means a discharge path (along the direction of the insulator ribs).
In general, the surface creep line is defined as the linear distance (or spacing), i.e. the ratio of the creep line to the linear distance between the working conductor and the ground, when the insulation is contemplated for normal use and under contaminated and strongly indexed conditions. is considered to be sufficiently high if it is at least equal to 2 or 3 or more, respectively, when considering the insulators used in

It is therefore clear that possible electrical discharges occurring in the gap between the resin-bonded glass fiber centerbody and the rib coating will destroy the insulation, which will then drop below the predicted level and furthermore, the electrical discharge will occur. Because of the damage caused by the short circuit, it will deteriorate without shorting until it reaches a lower level.

The methods of coupling a resin-bonded glass fiber body and a rib coating that have been practiced so far according to the prior art cannot prevent electrical discharge in the gap between the glass fiber body and the coating. showing undesirable drawbacks.

In fact, silicone greases, for example, exhibit a pumping effect due to the elongation exhibited by the rod-shaped center body made of resin-bonded glass fibers under the action of mechanical tensile stresses and the consequent compression exerted on the center body by the rib coating. Easy to accept. In this embodiment, the silicone grease is expelled from the gap between the bar or rod and the coating and is not sucked in again when the compression exerted by the coating is reduced in the case of a reduction or elimination of the tensile stress. Therefore, in the above-mentioned gap, the narrow hole or void acts effectively and easily attracts moisture infiltration and undesired discharge along the central body (bar or hollow cylinder shape) into the rib coating. .

Also, on the one hand, certain coupling resins may have two types of coupling resins that are different from each other or different from the resin itself.
When coupling a seed material (i.e., a resin-bonded glass fiber body and a rib coating, which may be prepared, for example, from PTFE), it is subjected to shear stress along the centerbody, which also causes contamination and discharge in the voids. to induce

The small voids formed in the gap between the central body and the coating allow the diffusion of moisture and the generation of localized discharges, as already pointed out. These shortcomings ultimately lead to the possibility that the metal terminals of the insulator along the center body (bar or cylindrical pipe) may A direct and continuous total discharge suddenly occurs. Thus, the insulator is taken out of service immediately or during a short circuit, since it is irreversibly dangerous.

Flame resistance and self-extinguishing properties should also not be ignored; it is better to have these properties as high as possible; however, in the organic materials that have been used hitherto according to conventional methods, they are quite low and therefore have flame resistance. However, it was almost ineffective.

One aim of the present invention is to eliminate the drawbacks illustrated above by fundamentally and decisively solving the problem of achieving complete adhesion between the resin-bonded glass fiber body and the rib coating. .

Another object of the present invention is to provide a composite type of low voltage, high voltage and very high voltage electrical insulators comprising a resin-bonded glass fiber body (rod-shaped core) and a rib coating prepared from a suitable elastic organic material. The object of the present invention is to provide an insulator in which the generation of tensile shear stresses or creep stresses between the support core and the rib coating is prevented by the high elasticity of the rib coating.

Another object of the present invention is to provide an insulator of the type described above with other disadvantages due to the low consistency existing between the resin-bonded glass fiber body and the rib coating, as noted in the prior art. The objective is to obtain an insulator that can eliminate all of the

A further object of the invention is to provide an insulator of the type mentioned above, which has a suitable anti-tracking and corrosion-resistant formulation and which, in addition to elasticity, aging resistance and fire spread resistance (self-extinguishing), has good impermeability. and to produce an insulator with a rib coating prepared from a material selected from ethylene-propylene elastomer having high properties of water repellency.

The main object of the invention is therefore to carry out a method for manufacturing an electrical insulator according to the invention, which allows achieving the above objects.

These and other objects will become more apparent to those skilled in the art from the detailed description below.

Thus, the above object is to produce a composite type of low-, high-, and ultra-high-voltage electrical equipment consisting of a resin-bonded glass fiber supported product or core in the form of a rod with a rib coating and metal connections prepared from an organic material. An insulator, in which a resin-bonded glass fiber core in the form of a solid bar or a hollow cylinder, depending on the intended use, is completely covered with an ethylene-propylene elastomer, preferably in the form of ribs, supported by a hollow sleeve. this hollow sleeve is also prepared from an ethylene-propylene elastomer whose quality and properties match that of the ethylene-propylene elastomer constituting the ribs, and is preferably integral with the ribs; and the material of manufacture of the rib coating. By using a room temperature self-curing blend based on a low unsaturation olefin polymer similar to, and compatible with, the ethylene-propylene blend described above, the resin-bonded glass fiber core described above is coated with elastomer. Rib coating is advantageously achieved by electrical insulators such that the ribs are also preferably grafted onto the sleeve and also between the ribs.

The electrical insulator of the present invention, which is capable of achieving the objects exemplified above, provides a mold for forming an all-elastomeric rib coating combined with a rod-shaped support center made of resin-bonded glass fibers. ; the surface of the hollow body, in the form of a solid bar or hollow cylinder, depending on the intended use, is sandblasted, sanded with a stone file or abrasive paper, and with a suitable adhesion-promoting mastic (so-called "primer"); placing the center body in the pre-positioned mold, such that the center body is within the mold and supported at its edges; , in the same mold, on the rod-shaped center body, a rib coating is entirely molded using a high-characteristic ethylene-propylene elastomer as the molding material and according to one of the known methods selected from the transfer method and the injection method. and curing; and finally, removing the entire insulator thus formed from said mode.

As an alternative to the above method, it is also possible to prepare the rib coatings separately and assemble them one after another. In such cases, the insulator is assembled after first rubberizing the support core with an ethylene-propylene elastomer and separately molding the ribs with the same ethylene-propylene elastomer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The object of the present invention, low-voltage, high-voltage, and ultra-high-voltage electrical insulators manufactured from resin-bonded glass fibers and ethylene-propylene elastomers, as well as methods of manufacturing the same, will be explained in detail below with reference to the accompanying drawings. It should be noted that the attached figures are shown for illustrative purposes only.

FIG. 1 shows an electrical insulator according to the invention,
Partial cross-section of an insulator having a support center body in the form of a solid bar, on which a sleeve-shaped rubberization has previously been applied and on which ribs have been applied; It is an elevational view.

Figure 1-A shows an electrical insulator according to the invention having a supporting center body in the form of a solid bar, on which the entire rib coating is integrally molded; FIG. 3 is a partial cross-sectional view of an insulator.

FIG. 2 shows an electrical insulator according to the invention,
an insulator having a support center body in the form of a hollow cylinder, on which an inner and outer sleeve-shaped rubberization has previously been applied and on which ribs have been applied; It is a partially sectional elevational view of the body.

Figure 2-A shows an electrical insulator according to the invention having a support center body in the form of a hollow cylinder, with a rib coating integrally molded directly onto the hollow cylinder; FIG. 3 is a partial cross-sectional view of an insulator in which a sleeve-shaped rubberization is subsequently applied on the inside of such a hollow cylinder;

Referring to the above drawings, the high voltage electrical insulator made of resin-bonded glass fiber and ethylene-propylene elastomer, which constitutes the object of the present invention, is of solid bar type 1 (Fig. 1 and 1-A).
Figure 1) or hollow cylinder type 2 (Figure 2 and Figure 2-A) of resin-bonded glass fiber products or rod-shaped support centers, which include 7 and 7 in Figure 1-A. A rib coating is applied, which may be integral as at 8 in Figure 2-A, or may consist of a separate sleeve-shaped rubber coating as at 3 in Figure 1 and 4 in Figure 2; On the sleeve-shaped rubberized sleeves 3 and 4, respectively,
Ribs 5 and 6 are applied sequentially. Incidentally, if the rod-shaped support center body made of resin-bonded glass fiber consists of a hollow cylinder 2 as shown in FIG. 2 and FIG.
A sleeve-shaped rubberization 10 is also foreseen inside the hollow cylinder 2 (usually employed when the insulator is intended for use as a bushing insulator). Thus, such an inner rubberization located at position 14, precisely at the cylinder end, ensures complete coverage of the resin-bonded glass fiber body 2 and thus achieves complete protection. It can be combined with the rubberized outer sleeve shape without breaking continuity.

Generally, the insulation is terminated by two metal terminals 9 located at the ends of the support core. This terminal 9 is fixed to the central body according to one of the fastening methods known in the art (conical ends, insertion wedges, external notches, compression fastenings, application of external and internal cones, wrapping, etc.) . However, if the rib coating is integrally molded, different types of fasteners may be employed, such as in the case where resin-bonded glass fiber bodies with flared ends may be manufactured as detailed below.

The method of manufacturing an insulator according to the various embodiments exemplified above includes the following steps according to the present invention.

It is in the form of resin-bonded glass fiber rods, either of solid bar type 1 or of hollow cylinder type 2 (the choice of which depends, of course, on the final type of insulation to be obtained), prefabricated according to customary methods. The central body is the starting member.

In either case, the centrosomes are pretreated prior to any other operations. More particularly, the center body is sandblasted, sanded or sanded with abrasive paper according to conventional techniques to increase the contact surface and improve adhesion of the coating blend. As an alternative to sandblasting or sanding, it is possible to apply a fixative, a so-called "primer", to the surface of the center body (bar or hollow cylinder). After this pretreatment, one can proceed to apply the organic elastomeric material. More specifically, the centerbody can be provided with a rib coating prepared from an ethylene-propylene elastomer. Such a coating consists either integrally 7 or 8 as previously explained, or separately of a sleeve-shaped rubberization 3 or 4 and ribs 5 or 6 applied thereto.

Integrated coaching (Figures 1-A and 2-A)
In the case of FIG. 1, a mold is prepared in order to form the rib coating 7 or 8 which is to be connected to the rod-shaped central body 1 or 2. The center body is placed in this mold and supported at both ends. Then,
The entire elastomeric rib coating is molded onto the rod-shaped center body according to transfer or injection methods and cured. Finally, the entire insulator thus formed is removed from the mold.

In the case of insulators in which the central body is of the solid bar type, the manufacturing process ends at this stage. On the other hand, in the case of insulators whose central body is of the hollow cylinder type, a sleeve-shaped rubberization of the inner surface must then be carried out according to the method described below. The preparation of the coating is then carried out in a continuous process. However, this inner rubberized
Optionally, this can be done before molding the entire rib coating.

Alternatively, in the case of separately prepared coatings, the rod-shaped center body is first coated with a hollow layer (sleeve) of EPR elastomer. For the sake of simplicity, this operation will hereinafter be referred to as rubberizing.

When the central body consists of a solid bar, the rubberization of the sleeve shape can be obtained according to one of the following methods: (a) mold hardening by compression, (b) mold hardening by transfer, (c) (d) extrusion in a T-head extruder followed by steam autoclave or liquid bath (e.g. molten salt liquid bath);
hardening at.

On the other hand, when the center body is in the shape of a hollow cylinder, the elastomeric hollow layer (rubberized) can be prepared according to one of the following methods, in exactly the same way as the corresponding process used for solid bars: (b) Molding hardening by transfer, (c) Molding hardening by injection.

The inner and outer surfaces of the hollow cylinder are rubberized simultaneously by working according to any of the methods described above.

The sleeve-shaped rubberization of the hollow cylinder-shaped center body can also be carried out in two steps: - the outer surface, which can be achieved by any of the methods listed in (a) to (d) for said solid bar center body; - Rubberization of the inner surface, which can be achieved according to the following method: A pipe previously prepared from a green blend and thick enough to be extruded is introduced into the cylinder cavity, where it is A suitably shaped inflatable air tube is attached to the inner surface of the resin-bonded fiberglass cylinder. At this time,
The air tube is introduced into the pipe prepared from the green blend and allowed to expand during curing, which occurs in an oven, a liquid bath at a suitable temperature, or a steam autoclave. The pressure inside the blended pipe required to seal it against the inside surface of the resin-bonded fiberglass cylinder is determined by the pressure applied to the blended pipe by a suitable material (e.g., bicarbonate) that releases gas at the curing temperature, resulting in a pressure increase. It can also be achieved by sodium).

The rubberized blend used to form the elastomeric hollow layer and coat the solid bar and the blend used to form the two elastomeric hollow layers and coat the inner and outer surfaces of the hollow cylinder are the blends used to form the ribs. have the same composition. The formation will be explained below.

The shaping of the ribs can be carried out according to the method of shaping groups of mutually integral units. When the ribs are manufactured as groups of two or more regularly consecutive units that mutually constitute a whole, the following forming methods are used: (b) mold hardening by transfer, (c) mold hardening by injection.

When curing is complete, a group of integral ribs is removed from each mold.

Various methods can be used to assemble the insulator.

- According to the first method, the ribs to be preformed in groups of units are preferably pretreated (i.e. sandblasted or sanded or coated with a primer as described above) and the ribs are rubberized in the center body and the ribs are preformed in groups of several units. Ethylene-propylene blend (EPR) that can be used for molding
A room temperature self-curing blend based on a less saturated olefin polymer similar to or compatible with the blend can be applied by slip fit or by forced attachment onto a resin bonded glass fiber supported core. Drive it into place.

More specifically, the self-curing blend used includes an amorphous olefin terpolymer with a low degree of unsaturation consisting of ethylene, α-olefin, and a cyclic or acyclic polyene having a nonconjugated double bond; Reinforcing fillers preferably include some antioxidants, pigments and other additives as well as organic hydroperoxides as hardeners. This blend is prepared according to Italian Patent No. 780429, owned by Montedeison Etse Pia.

- according to the second method, the groups of preformed ribs are preferably slip-fit or drive-fit by forced assembly onto the resin-bonded fiberglass support core, but in contrast to the above-mentioned method, The supporting core used in this case is already rubberized. (i.e. already covered with an elastomeric tubular coat). Thus, it is precisely the tubular coat or sleeve coated with a self-curing blend that ensures close adhesion between the rib groups and the tubular coat in the same manner as in the first method above. The same blend ensures direct contact between the ribs and the treated but non-rubberized support core.

- According to the third and final assembly method, groups of preformed and partially (precisely 50%) hardened ribs are used. This is preferably slid onto a resin-bonded glass fiber core (bar or hollow cylinder) with a rubber coating also having a 50% partial cure, or by means of forced attachment. Can be driven into place. The thus assembled unit is placed in a suitable molding machine to complete curing. This is achieved by radial compression in a mold and heating at a temperature in the range 160-210°C, preferably 160-180°C.

By using the technique according to this third assembly method, it is possible to obtain excellent results in terms of adhesion between the various assembled members without using a self-curing adhesive. This is conversely foreseen by the other two assembly methods.

One thing to keep in mind about cure times is that at any given process step, it takes between 5 and 45 minutes to fully cure the ethylene-propylene elastomer blend used.
It takes 10 to 40 minutes for further identification.
Therefore, as exemplified in the third insulator assembly method above, curing is performed to 50% in the first stage. It takes 3 to 22 minutes, or more specifically 5 to 20 minutes. The second stage of curing takes many minutes and cures the entire assembled insulation by 50-100%.

Regarding the curing temperature to which the blend is exposed for the specified period mentioned above, it is the same temperature as indicated in connection with the third assembly method already mentioned for all the conventional methods mentioned above, i.e. 160-210°C, preferably 160°C.
~180℃.

The adhesive blend is self-curing. Therefore,
The blend cures at room temperature as described above. Thus, the widest curing temperature range is 5 to 60°C. The time required to complete this process varies from 20 to 48 hours, and at most 20 to 96 hours.

As pointed out in the above description of the insulator produced in accordance with the present invention, the metal terminals are secured to the support core according to known conventional fastening methods,
However, when molding the rib coating in one piece, as from the beginning, the ends of the support core should be molded as oversized heads with respect to the support rod part, and the supporting metal connections 9 of the insulators should not slip off. The supporting core can be provided with an appropriate undercut as a mooring safety measure to deal with the danger.

In fact, by molding the integral rib coating directly onto the supporting centerpiece, it is no longer necessary to slip-fit or drive-fit the ribs onto the centerpiece. Thus, a prefabricated centerbody with an oversized head can be used, which represents another benefit of the integral rib coating molding method.

Of course, structural and operationally equivalent modifications and changes may be made without departing from the scope of the invention, as previously described and illustrated.

For example, the method of forming rib coatings can be made according to another variant by covering the rod-shaped supporting core with an elastomer hollow layer (sleeve), i.e. rubber as in the case of separately prepared rib coatings. drawing, but keeping the degree of coating fairly low; the rubberized product or center body is then placed in a suitably pre-positioned mold and therein, as in the case of a full rib coating constructed as a whole. , by molding the ribs all integrally onto a pre-rubberized product or central body.

[Brief explanation of the drawing]

FIG. 1 shows an electrical insulator according to the invention,
Partial cross-section of an insulator having a support center body in the form of a solid bar, on which a sleeve-shaped rubberization has previously been applied and on which ribs have been applied; It is an elevational view. Figure 1-A is
1 is a partial cross-sectional view of an electrical insulator according to the invention, having a support center body in the form of a solid bar, on which the entire rib coating is integrally molded; FIG. be. FIG. 2 shows an electrical insulator according to the invention having a supporting center body in the form of a hollow cylinder, on which inner and outer sleeve-shaped rubberization has been previously applied. FIG. 3 is an elevational view, partially in section, of an insulator with ribs applied on the outer sleeve; Figure 2-A shows an electrical insulator according to the invention,
It has a support center body in the form of a hollow cylinder, on which a rib coating is integrally molded directly, and on the inside of which a sleeve-shaped rubberization is subsequently applied. FIG. The explanations of the symbols representing the main parts in the attached drawings are as follows: 1: Solid bar-shaped support center body;
2: Hollow cylinder-shaped support center body, 3, 4,
10: Sleeve-shaped hollow layer, 5, 6, 7, 8: Ribs, 9: Terminal or connecting body, 14: Hollow cylinder end.

Claims (1)

Claims: 1. A low-, high-, and extra-high-voltage electrical insulator comprising a rod-shaped resin-bonded glass fiber support product or center body having a rib coating prepared from an organic material, the rib coating comprising: The supporting center body 1 or 2 is completely coated, and the coating is made of an ethylene-propylene elastomer having high elasticity, anti-tracking properties, corrosion resistance, aging resistance, self-extinguishing properties and water repellency. Furthermore, the rib coating is made integral 7 or 8, and the joint between the rib coating 7 or 8 and the central body 1 or 2 is made of ethylene, α-olefin, non-conjugated double bonds. By using a room temperature self-curing blend containing a low unsaturation amorphous olefin terpolymer consisting of a cyclic or acyclic polyene with An electrical insulator obtained by 2. The rib coating is formed as a rib 5 or 6 supported by a sleeve-shaped hollow layer 3 or 4 prepared from an ethylene-propylene elastomer whose quality and properties correspond to that of the ethylene-propylene elastomer constituting the rib; The joint between the rib 5 or 6 and the sleeve 3 or 4 is a ternary amorphous olefin with a low degree of unsaturation made of ethylene, α-olefin, and cyclic or acyclic polyethylene having non-conjugated double bonds. 2. Electrical insulation according to claim 1, obtained by using a room temperature self-curing blend comprising a polymer and a reinforcing filler and containing an organic hydroperoxide as a hardening agent. 3. Electrical insulator according to claim 1, characterized in that the rod-shaped central body is a solid bar 1 of resin-bonded glass fiber. 4. Electrical insulator according to claim 1, characterized in that the rod-shaped central body is a hollow cylinder 2 of resin-bonded glass fibers. 5 The hollow cylinder 2 has its cylinder end 1
4, another sleeve-shaped hollow layer 1 made of ethylene-propylene elastomer, which connects with the outer hollow sleeve 4 without breaking the continuity.
0, such that the ethylene-propylene elastomer of this inner sleeve 10 exhibits the same qualities and properties as the ethylene-propylene elastomer of which the outer sleeve 4 is made. The electrical insulator according to item 1, 2 or 4. 6. Electrical insulation according to any one of claims 1 to 5, characterized in that the room temperature self-curing blend further comprises antioxidants, pigments and other additives. 7. An electrical insulator comprising a rod-shaped resin-bonded glass fiber support core with a rib coating prepared from an organic material, said rib coating completely covering said support core 1 or 2, and The coating is made from an ethylene-propylene elastomer with high elasticity, anti-tracking, erosion resistance, aging resistance, self-extinguishing properties and water repellency; The joint between the rib coating 7 or 8 and the center body 1 or 2 is made of a non-saturated material with a low degree of unsaturation made of ethylene, α-olefin, cyclic or acyclic polyene having non-conjugated double bonds. A method for producing an insulator obtained by using a room temperature self-curing blend containing a crystalline olefin terpolymer and a reinforcing filler and containing an organic hydroperoxide as a hardening agent, the insulator being resin-bonded to a glass. pre-positioning a mold to form the entire elastomeric rib coating to be integrally bonded to a support product made of fibers or a rod-shaped center body; the surface of said center body being sandblasted, sanded or polished;
and applying an adhesion-promoting mastic; placing the centerbody or article in the mold, the centerbody being within the mold and supported at its edges; Then, in the same mold, on the rod-shaped center body, ethylene is applied as a molding material.
A method comprising the steps of: molding and curing the entire rib coating using a propylene elastomer and according to either a transfer method or an injection method; and finally removing the entire thus formed insulation from said mold. . 8. A method for manufacturing an insulator according to claim 7, characterized in that curing is carried out at a temperature in the range of 160 to 210°C. 9. The method of manufacturing an insulator according to claim 7, wherein the curing is completed in a time range of 5 to 45 minutes. 10. A method for producing an insulator according to claim 7, characterized in that the self-curing blend is cured at a temperature of 5 to 60°C and for a time of 20 to 96 hours. 11. The central body is suitable for accommodating a metal connection according to any method selected from notching, wrapping, plugging, application of at least one external cone, application of an internal cone and similar means. 8. The method of manufacturing an insulator according to claim 7, further comprising a shaped end portion. 12. Prior to any other process step, the central body is formed into a metal connection according to any method selected from notching, wrapping, plugging, applying at least one outer cone and applying an inner cone. 8. An insulation according to claim 7, characterized in that the insulation is provided with an end portion having a shape suitable for accommodating the insulation, and is undercut to anchor a supporting metal connection of the insulation. How the body is manufactured. 13. A method of manufacturing an insulator according to claim 12, wherein each end is formed as an oversized head. 14 An electrical insulator comprising a resin-bonded glass fiber support core in the form of a hollow cylindrical rod with a rib coating prepared from an organic material, said rib coating completely covering said support core 1 or 2; and the coaching is
Made from ethylene-propylene elastomer with high elasticity, anti-tracking properties, erosion resistance, aging resistance, self-extinguishing properties and water repellency.
Furthermore, the rib coating is made integral 7 or 8 and the joint between this rib coating 7 or 8 and the central body 1 or 2 is made of ethylene, α-olefin, cyclic or Insulation obtained by using a room temperature self-curing blend containing a low unsaturation amorphous olefin terpolymer consisting of an acyclic polyene and a reinforcing filler and containing an organic hydroperoxide as a curing agent. A method of manufacturing a body, comprising prepositioning a mold to form the entire rib coating of an elastomer integrally bonded to a support article made of resin-bonded glass fibers or a central body in the form of a hollow cylinder rod; treating the surface of the centerbody according to a technique selected from the group consisting of sandblasting, sanding or polishing, and applying with an adhesion-promoting mastic; placing the centerbody or article in the mold, then applying the The center body is located in said mold and is supported at its edges; then, in the same mold, on the center body in the form of a hollow cylindrical rod, using an ethylene-propylene elastomer as the molding material and by the transfer method or molding and curing the entire rib coating according to any of the injection methods; removing the entire insulation thus formed from the mold; Rubberized with an ethylene-propylene elastomer identical to that of the ethylene-propylene elastomer constituting the coating, and this rubberization introduces into said hollow cylinder a hollow sleeve of matched dimensions prepared from a raw ethylene-propylene elastomer blend. The sleeve is then placed on the inner surface by (1) inflating a suitable air tube contained within the sleeve during curing; or (2) ) by creating the required pressure in said hollow sleeve with a suitable substance, such as sodium bicarbonate, which vaporizes at the curing temperature;
A process characterized by curing by heating in an oven, liquid bath or steam autoclave. 15. A method for producing an insulator according to claim 14, characterized in that the self-curing blend is cured at a temperature of 5 to 60°C and for a time of 20 to 96 hours. 16. The central body is suitable for accommodating a metal connection according to any method selected from notching, wrapping, inserting, application of at least one external cone, application of an internal cone and similar means. 15. The method of manufacturing an insulator according to claim 14, further comprising a shaped end portion.