JPH0213528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to reversible sealing assemblies, methods of encapsulating objects in such assemblies, and the components that make up the assemblies.

Recoverable containment aggregates are used extensively and
One of its important applications is the encapsulation and protection of cable connections with reversible outer sleeves. In this case, the outer sleeve contracts around the joint and acts as an encapsulating protection. in general,
A restorable article is an article whose dimensional size substantially changes when subjected to appropriate treatment. Of particular interest here are heat-recoverable articles whose dimensional size is substantially changed by heat treatment. The heat recoverable article can be manufactured by deforming a material having a dimensionally heat stable form. However, as disclosed in U.S. Patent No. 2027962,
The original dimensionally heat-stable form may be a temporary form, for example, in a continuous process in which an extruded tube is expanded while hot into a dimensionally heat-stable form. Alternatively, a preformed dimensionally heat-stable article may be transformed into a dimensionally heat-stable form in a separate step. In producing dimensionally recoverable articles, the composition may be crosslinked at any stage of the manufacturing process to achieve the desired additional dimensional recoverability.

The invention also relates to a recoverable sleeve whose recoverability derives from mechanical resistance to deformation rather than dynamic stability. In such cases, the recoverable sleeve may have an added retaining material, such as one that can return to its stable state by removing, breaking, or melting the inner sleeve of the recoverable sleeve. It is.

The sequestration assembly may include various other components. For example, a liner may be provided between the cable bond and the resilient sleeve to provide a moisture barrier or physical support for the sleeve. One particularly useful form of liner that can be wrapped around the joint prior to restoration of the sleeve is described in our British Patent Application No. 7931402. The liner and resilient sleeve may also be provided as an integral laminate.

However, such liners can be expensive in some cases, especially when physical support is required throughout for large diameter heat recoverable sleeves. We have devised a sealing assembly that combines high installation flexibility with high static load and impact load resistance.

The invention consists of a recoverable outer sleeve that can surround the object to be sealed, and a liner inside the sleeve that can surround the object, the liner comprising an inner thermoplastic support layer and an outer heat-blocking layer. This provides a restoration static sealing assembly.

Preferably, the outer sleeve is thermally recoverable, in which case the thermal barrier layer may be capable of preventing thermal deformation of the support layer during thermal recovery of the sleeve. If the outer sleeve is recoverable by means other than heat, the thermal barrier layer should be capable of imparting sufficient heat resistance to whatever conditions the assembly is subjected to. Desirably, the liner further includes a moisture barrier that is substantially vapor impermeable, and each layer of the liner desirably is substantially incapable of capillary migration of liquid. The moisture barrier layer may be an additional layer or the function of preventing moisture intrusion may be achieved in any of the layers present.

The invention also provides a liner suitable for use in the assemblage of the invention, with the layers of the liner preferably being bonded together to form a laminate. The present invention further provides a method of sealing an object, such as a cable joint, comprising: positioning a liner and a reversible sleeve around the object; and performing restoration of the sleeve. Consisting of If the liner and sleeve or liner is not a bonded laminate, the various layers can be applied separately in the desired order.
Alternatively, they may all be placed together around the object if desired. Additionally, the invention provides a kit of parts for making an assembly.

Therefore, the desired properties of the liner can be achieved by using a support layer that has the required strength and flexibility and is able to withstand the forces of the outer sleeve during its restoration, and the lack of heat resistance in the support layer can be achieved by providing thermal insulation. It will be appreciated that the use of layers can be compensated.

The new assembly liner can resist delamination of its layers and can resist water ingress due to capillary migration (core material). Otherwise, this capillary movement would cause water or other moisture to bypass a moisture barrier layer that may be provided via the edges of the liner.

The idea of using a material for the support layer that is itself thermoplastic allows great freedom in the choice of this material. On the other hand, thermal deformation of this thermoplastic support layer during recovery of the outer sleeve can be substantially avoided by using a foamed thermal barrier layer.
Furthermore, since thermoplastic materials are relatively inexpensive and easy to form by any suitable method, such as molding, extrusion, or other heat deformation methods, any form of support layer can be readily provided. The length of the support layer piece is not critical, but it should not be so long that collapse occurs when the sleeve recovers. The strength may be increased, for example, by stacking two or three supporting layers. Also, the thickness of the material may be increased.

The material of the support layer is appropriately determined, for example, taking into consideration the strength and heat that must be withstood during and after thermal restoration of the sleeve. The preferred material for the support layer is an olefinic polymer such as polypropylene filled with calcium carbonate, although other suitable thermoplastics such as high density polyethylene or polycarbonate may also be used. Desirable properties of the support layer include resistance to low temperature impact, a sufficiently high deflection temperature to avoid collapse under stress, and a suitable flexural modulus. Appropriate flexure temperature at 264p.si
55-65°C, preferably about 62°C, and suitable impact strengths are 6-10, preferably about 8 ftld/in at 23°C, and 0.8-12, preferably 1 fnld/in at 18°C. Knowing these requirements, one skilled in the art will be able to easily select suitable materials.

The invention is particularly suitable for treating cable joint closures with a diameter of 100 mm or more, especially 126 mm or more and a length of 250 to 300 mm, preferably about 300 mm. This size is approximately the upper limit for satisfactory operation using the cable sleeve liner described in the aforementioned British application. A filled polypropylene sheet is preferred as the support layer in this invention. The reason is that this sheet has high strength, high melting point (160°C) and good flexibility at room temperature. Additionally, installation temperatures can exceed 160°C near the liner;
The thermal barrier layer of the invention can be used to avoid any difficulties in this respect, as mentioned above.

The filled polypropylene sheet has a thickness of 0.8~1.2
Preferably, it is mm. Also, the sheet does not necessarily have to have exactly the same dimensions as the heat barrier layer. A well-chosen support layer will prevent any collapse or deformation of the heat-shrinkable sleeve during recovery, while providing the strength and protection to prevent permanent failure of the system when subjected to mechanical loads and/or impacts. Can provide flexibility. This invention at least
It is expected that it can be used or applied to cable joint closures with diameters up to 200 mm.

The thermal barrier layer may be non-thermoplastic, such as a closed cell foam that minimizes moisture penetration (e.g.
0.05, especially 0.04b/ft ³ ),
the working temperature encountered during use, i.e. at least 140℃;
In particular, any foam material that can withstand temperatures of 160° C. or higher may be used. A suitable thermal conductivity for the foam is between 0.3 and 0.35 per inch, particularly 0.32 BTU/hrsqft. Although it is desirable that the foam be flexible, even relatively rigid foams may have suitable crease lines or other means to help wrap the foam around the object to be sealed. If so, you can use it. Most closed cell, non-hygroscopic foams with the required heat resistance are suitable, with neoprene, polyolefins and the like being particularly preferred. It may also be cross-linked, which may be advantageous as it adds further thermal stability. One suitable method of crosslinking is irradiation. 2 of the above heat shielding materials
More than one layer may be used between the support layer and the sleeve. Foamed material here simply refers to material that contains many small pores within its bulk. Therefore, there is no intention to limit the method of manufacturing the material. The thickness of the foam and the size and distribution of its pores can be selected according to the intended use of the product. In any thermal restoration process,
The rate of heat transfer is one consideration, and the satisfactory value depends on the fragility of the support layer and the efficiency of the thermal barrier layer. The desired thickness of the foam layer is 0.8 mm, but it may be slightly thicker or thinner than this. The total density of the cells is preferably 90 to 110, preferably 100 Kg/m ³ . The heat barrier layer may also consist of a non-woven fibrous material, for example a piece of compressed board.
Or it may be a plurality of layers.

Preferably, a moisture barrier layer that is substantially vapor impermeable is included in the assembly, particularly between the foamed thermal barrier layer and the support layer. This moisture barrier layer is preferably a flexible metal layer, such as aluminum, and can be placed anywhere in the assembly if desired. For example, on the outer surface of the foam, between the outer sleeve and the foamed layer, or within the sleeve itself, preferably on the inner surface of the sleeve, the moisture barrier layer then seals the closure. Ordinary glue or mastic may be applied for this purpose. The thickness of the aluminum or other metal must be such that it will not break when the assembly is made. 10-30μ, preferably 12
A thickness of ~25μ, particularly preferably about 15μ, is desired.

The support layer itself may be laminated to the heat barrier foam layer or the moisture barrier/heat barrier laminate layer, or may be provided as a separate layer. However, it is preferred that the support layer be adhered to the heat barrier layer and any other layers present to form a laminated support liner. Appropriate adhesive method and adhesive (pressure sensitive or other adhesive)
can be easily selected by someone skilled in the technology. Heat activated adhesives may also be used, of which polyamides are preferred. See US Pat. No. 4,181,775 for suitable adhesives.

If the support layer is part of a support liner that is laminated with at least one other layer, it may be desirable to remove a long longitudinal length of the support layer at one end to expose a strip of the other layer. This exposed end portion then becomes a tag that, by adhesion to the opposite end of the liner or to other portions, holds the liner in a substantially cylindrical or other shape surrounding the object to be protected. available for. Preferred methods for such stripping include scoring a defect line along the length at an appropriate distance from one end of the support layer, or scoring one side of the support layer, thereby There is a method of grasping the support layer and tearing it into thin strips. A number of such defect lines may be provided and a single liner design may be used to protect objects of different thicknesses. This line may be the same as, or may be in addition to, the line drawn to curve the otherwise flat liner around the object. An additional or alternative function of the tag is to protect the outer sleeve from the generally sharp edges of the support layers that protrude at the points of overlap of the support layers. Conveniently, the laminated support layer referred to here is made in a continuous manner using a pressure sensitive adhesive. This adhesive allows the elongate support layer to be easily removed leaving the pressure sensitive tag. This laminate support layer is preferably a three-layer laminate with the functions of support (preferably polypropylene), heat barrier (preferably foam) and moisture barrier (preferably aluminum sheet), and this laminate support layer is Removal of the pieces forms a foam-aluminum adhesive tag.

Each end of the liner may be gradually tapered to match the diameter of the object it surrounds. The advantage is that it forms a better seal at the end of the liner and reduces the number of sharp points or edges that can damage the outer sleeve. The tapered end of the liner is preferably formed by providing a longitudinal slit at the distal end of the support layer, thus closing the distal end of the liner into a conical shape. Preferably, the slit is formed by removing a tapered member from the support layer to define a series of opposing tapered fingers. Such an arrangement allows the conical end to be formed without gaps.

BRIEF DESCRIPTION OF THE DRAWINGS Aspects of embodiments of the invention will now be described with reference to the accompanying drawings, in which: FIG.

1 and 2 show the closure assembly according to the invention before and after restoration of the outer sleeve. FIGS. 3 and 4 show support members according to the invention, which are used in the assembly shown in FIGS. 1 and 2. 5 and 6 show the detailed structure of the support member when viewed from the end. 9 is a cross-sectional view of a portion of the outer sleeve and inner sleeve liner of FIGS. 7 and 8; FIG. FIG. 9 shows a perspective view of the sleeve liner.

1 and 2, cables 1 are joined by known means, such as crimp ferrules 2, and a support liner 3 surrounds this joint. The liner has a slit-like end 4 with tapered fingers 4 which can be bent inward to form a taper from the liner 3 towards the cable 1.

A heat-recoverable sleeve 5 surrounds the liner and extends beyond its ends, allowing the assembly to be sealed after heat-recovery as shown in FIG. The inner surface of the sleeve is typically coated with a heat-activated adhesive to ensure a moisture-tight seal.

The tapered finger 4 of the liner 3 has a third
This is clearly shown in FIG. Furthermore, in this example, it is shown in FIG. 3 that the liner 3 is provided with a heat-blocking layer 6 of laminated foamed polymer over substantially the entire outer surface thereof.
FIG. 3 also shows the calcium carbonate-filled polypropylene support layer 7 that makes up the liner, and also shows in a perspective view the tapered fingers 4 of the liner bent inward to wrap around the cable 1. be. Since this finger is preferably formed only of a support layer, a continuous web of moisture barrier may be provided. This provides an excellent seal with inwardly bent edges (US Application No. 155,817).

The laminate structure of the liner in this example is
It is also shown in end view in FIG. 5 and in an enlarged detail in FIG. 6, both figures using the same numerals 6 and 7 for the foam and polypropylene layers, respectively.

Lamination can also be carried out by any suitable means such as an adhesive. The method also applies to liners that further incorporate a layer of moisture-impermeable flexible material (not shown), preferably a metal film such as aluminum, into the laminate. It may be incorporated between the foam layer and the polypropylene layer of the liner, or anywhere else.

7 and 8 show a portion of the sleeve liner 3 inside the heat-recoverable outer sleeve 5. FIG. The outer sleeve 5 has a coupling rail 10 and a sealing member 11 for holding the rail in contact.
There is. Such a sleeve is described in British Patent No. 1155470. The sleeve liner consists of a support layer 7, a moisture barrier layer 8 and a heat barrier layer 6, which layers are bonded together with a contact adhesive. It can be seen from FIG. 7 that if the sleeve liner 3 overlaps the rigid end 9 of the support layer, this end will press against the outer sleeve 5 in some cases. In FIG. 8, the strip of support layer 7 has been removed to expose the tag 13, which allows the overlap to be loose, thereby minimizing the risk of sleeve splitting in the event of restoration. This tag 13 may be used to adhere to a portion of the support layer so that the liner assumes the correct configuration around the object to be protected.

Figure 9 shows partially rolled sleeve liner 3.
shows. A defect line 12 is also provided to remove the strip of support layer 14 and, in the illustrated embodiment, expose the tag 13 of the moisture barrier-heat barrier laminate layer. The tag is preferably provided with a contact adhesive for adhering to the sleeve liner at 15.

The tapered fingers are preferably as shown in Figures 3 and 4, but may simply be straight slits or other shapes if necessary to taper the liner onto the cable.

In order to provide further flexibility in the portion of the support layer that bends to form a taper from the liner 3 towards the cable 1, small holes may be provided within the layer at the base of each finger. These perforations can prevent or reduce the formation of sharp points or sharp edges around the joint between the center portion of the rolled sleeve and each tapered end. Preferably, these small holes pass only through the support layer 7 and not through any adjacent heat or moisture barrier layers.

In use, the components of the assembly are arranged around the object to be sealed in the following order from the surface of the object: support layer, thermal barrier layer and then sleeve. Heat is then applied to restore the sleeve around the object. In this case, it is also advisable to arrange a moisture barrier layer around the object, in particular between the heat barrier layer and the outside of the assembly, or in the form of a sandwich between the heat barrier layer and the support layer. is the most desirable. The support layer and these barrier layers may of course be provided as an integral laminate.

Heat-recoverable sleeves may be made using elastic memory, for example as shown in US Pat. It may be any known tube-shaped or envelope-shaped sleeve that takes advantage of the elastomer's resilience after the support holding the sleeve is softened by heating.

[Brief explanation of drawings]

1 and 2 are a plan view and a partially sectional view showing the sealing assembly according to the present invention before and after the outer sleeve is restored, and FIGS. 3 and 4 are a support member according to the invention. , an assembled perspective view and a developed plan view of the components used in the assembly shown in FIGS. 1 and 2, FIGS. 5 and 6 are side views showing the detailed structure of the supporting member when viewed from the end, and FIGS. 7 and 8 are cross-sectional views of a portion of the outer sleeve and inner sleeve liner, and FIG. 9 is a perspective view of the sleeve liner, with 1 a cable, 2 a crimp ferrule, and 3
is the support liner, 4 is the tapered finger, and 5 is the support liner.
is a sleeve, 6 is a heat barrier layer, 7 is a support layer, 8 is a moisture barrier layer, 10 is a coupling rail, 11 is a sealing member,
13 indicates a tag.

Claims (1)

[Claims] 1. Consists of a resilient outer sleeve capable of surrounding the object to be sealed and a liner inside the sleeve capable of surrounding the object, the liner comprising a thermoplastic supporting inner layer and a liner capable of surrounding the object. CLAIMS 1. A reversible sealing assembly, characterized in that it has a thermally insulating outer layer. 2. The assembly of claim 1, wherein each layer of the liner is substantially incapable of capillary migration of liquid. 3. The assembly according to claim 1 or 2, wherein the sleeve is heat-recoverable and the heat-blocking layer is capable of preventing thermal deformation of the support layer during the heat-recovery of the sleeve during use. 4. Claims 1 to 3 in which the thermal barrier layer is a substantially closed-cell foamed polymeric material, preferably a neoprene foam or a polyolefin foam.
An aggregate described in any of the paragraphs. 5. The aggregate according to any one of claims 1 to 4, wherein the support layer is calcium carbonate-filled polypropylene. Claims 6: In use, the liner has a tapered end portion formed by internally joining tongues defined by adjacent longitudinal slits extending to the edge of the support layer. The aggregate described in any of Item 5. 7. An assembly according to claim 6, wherein the support layer has enlarged holes at the closed end of each slit. 8. Claims wherein the thermal barrier layer or layers overlap the support layer along its longitudinal edges and bond to portions of the liner to form tags that retain the liner around the object when the liner is in use. The aggregate according to any one of Items 1 to 7. 9. Claims 1 to 9, wherein a thermal barrier layer or layer overlaps the support layer along its longitudinal edge to form a tag that provides a barrier between said edge and the outer sleeve when the liner is in use. An aggregate according to any of Item 8. 10 An overlap is created by removing a lengthwise strip of the support layer from an adhesive laminate layer consisting of a support layer and a thermal barrier layer or other layer, and the adhesion of the laminate is such that removal of the strip reveals a pressure sensitive adhesive tag. 10. An assembly according to claim 8 or 9, which is carried out using a pressure-sensitive adhesive. 11. An assembly according to any one of claims 1 to 10, wherein the liner further comprises a substantially vapor-impermeable moisture barrier layer, preferably consisting of aluminum foil. 12. An assembly according to any of claims 1 to 11, wherein each layer of the liner is glued together. 13 consisting of a reversible outer sleeve capable of surrounding the object to be sealed and a liner inside the sleeve capable of surrounding the object, the liner having a thermoplastic supporting inner layer and a thermally insulating outer layer; A cable connection sealed using a reversible sealing assembly characterized by: 14. Consisting of a reversible outer sleeve capable of surrounding the object to be sealed and a liner inside the sleeve capable of surrounding the object, the liner having a thermoplastic supporting inner layer and a thermally insulating outer layer. A liner for a reversible sealing assembly, characterized in that the liner has a support layer adhered to another layer, the support layer having a defect line or score so that the support layer An aggregate liner that can be longitudinally stripped away to expose tags of other layers, which tags can be adhered to a portion of the liner to hold the liner around the object. 15 consisting of a reversible outer sleeve capable of surrounding the object to be sealed and a liner inside the sleeve capable of surrounding the object, the liner having a thermoplastic supporting inner layer and a heat-insulating outer layer; A liner for a reversible sealing assembly, characterized in that the liner has a support layer adhered to another layer, the support layer having a defect line or score so that the support layer The aggregate liner can be longitudinally slit to expose tags of other layers, which tags can provide coverage for the exposed edges of the support layer. 16. A liner capable of enclosing the object to be sealed, with a thermoplastic supporting inner layer and a heat-insulating outer layer, capable of enclosing the object, and having a thermoplastic supporting inner layer and a heat-insulating outer layer; an outer sleeve and a liner inside the sleeve capable of surrounding the object, the liner having an inner thermoplastic support layer and an outer heat-insulating layer. a liner having a support layer adhered to one layer, the support layer having a defect line or score so that longitudinal stripping of the support layer causes tagging of the other layer. an assembly liner that can be exposed and whose tags can be adhered to a portion of the liner to hold the liner around the object, or a retractable outer sleeve that can surround the object to be sealed and its A liner for a reversible closure assembly, characterized in that the liner is located inside the sleeve and is capable of surrounding the object, the liner having an inner thermoplastic supporting layer and an outer heat-insulating layer. , having a support layer adhered to one layer, the support layer having a defect line or score so that longitudinal stripping of the support layer may expose tags of the other layer. first placing an assembly liner around the object, the tag of which can provide coverage for exposed edges of the support layer, then placing a recoverable sleeve, and then carrying out recovery of the sleeve. A method of sealing off an object that involves a process. 17 consisting of a reversible outer sleeve capable of surrounding the object to be sealed and a liner inside the sleeve capable of surrounding the object, the liner having a thermoplastic supporting inner layer and a heat-insulating outer layer; An object sealing kit which is suitable for making a recoverable sealing assembly characterized in that it comprises a recoverable sleeve, a support layer, a heat barrier layer and optionally a moisture barrier layer.