GB2420488A

GB2420488A - A blast resistant refuse container made from plastics materials

Info

Publication number: GB2420488A
Application number: GB0425924A
Authority: GB
Inventors: Jeremy Bowman
Original assignee: Uponor Ltd UK
Current assignee: Uponor Ltd UK
Priority date: 2004-11-25
Filing date: 2004-11-25
Publication date: 2006-05-31
Anticipated expiration: 2024-11-25
Also published as: GB0425924D0; GB2420488B

Abstract

A blast resistant refuse container 1 comprises a body 2 formed from an extruded first plastics material with a high fast fracture resistance, and a base 3 formed from a second plastics material. The body and the base are fused together by means of an electrofusion element. The electrofusion element may be a separate electrofusion coupler 5, or be integral with the base 3. Both plastics materials may be a polyolefin, such as polyethylene.

Description

REFUSE CONTAINER

This invention relates to a refuse container, and more particularly to a refuse container having enhanced blast resistance.

In the specification the term "container having

enhanced blast resistance" is intended to refer to a container which is capable of containing or reducing the blast generated by an explosive device, or of channelling a blast away from persons in the vicinity of the container.

It is a known tactic of terrorist groups to place bombs and other explosive devices in litter bins in public places because a bin provides a convenient hiding place and because the bin shatters forming shrapnel when the explosive device detonates, which can add greatly to the damage and injury caused. This has resulted in the United Kingdom and other countries in the removal of litter bins from public areas, for example, railway stations and airports, to the great inconvenience of the travelling public.

It is known to manufacture explosion resistant casings for the transport of munitions or explosives, which casings are capable of withstanding explosions.

Such casings are typically constructed of outer and inner housings formed of a metal such as sheet steel, the housings being separated by a compressible or concussion resistant material. Such casings are expensive, bulky * . . S * * * 5 * * *5 S S S S S * S S * S * S S * * . . S S S S **S * . S I S * * * * 5I* 555 *IS * S and heavy, and would be unsuitable for use as refuse containers.

EP--A-02999Q2 describes a blast-resistant container comprising dishshaped outer and inner housings formed of steel which are separated by a layer of a vermiculite material. A removable basket is provided to enable the container to be used as a refuse bin.

GB-A-2222667 describes a bomb containment device for use as a receptacle for a suspect explosive device which comprises a tube formed of a winding of filament glass fibre incorporated into a bonding resin material, and provided with a net suspended midway in the tube forming a support for a suspect package. These containers are either too bulky, heavy and expensive to be used as refuse bins, or do not offer sufficient blast resistance to a bomb.

GB-A-2276530 describes a litter bin comprising a receptacle lined with a fabric of high tensile yarn to assist in containing the effect of an explosion within the bin. The bin incorporates a water reservoir and is of complex construction which would be uneconomic for mass production.

GB-A-2289399 describes a waste bin having inner and outer walls, the space there between being filled by a deformable energy absorbing medium sand. Such a bin is very heavy and would be quite difficult to empty.

* S * S * S * S * S ** * * S S * * * S S S S S S S * S * S S * S *S* * * 5 5 5 5 * S * SI **S *S* 5 5 GB-A-2279231 describes a bomb-resistant container, particularly for use as a refuse bin, comprising at least two interfitting spaced tubes. The tubes are formed of a spiral winding of fibres provided in a resin bass and separated by a layer of a compressible material. The construction is complex and expensive.

EP-A-0882659 describes a reinforced cylindrical trash can with a double wall, wherein said double wall consists of a first inner cylinder open at the top and bottom, serving to support a receptacle for deposited objects, and a second outer cylinder which is not directly attached to the first cylinder but which is coaxial therewith, open at the top and bottom, and separated from the first cylinder by an empty space, so that it can contain a deformation of the first cylinder as the result of an explosion. The trash can is formed from sheet metal and would be heavy and expensive to manufacture.

FP-A-2765l98 describes an explosion proof container which comprises three concentric independent steel layers. Such a container would-be very heavy and difficult to empty.

It can be seen from the above that very many unsuccessful attempts have been made to devise a suitable refuse container having enhanced blast resistance, which is both economical, for wide distribution in public places, and is practical and relatively lightweight for man-handling and emptying.

* I * I 4 * 4 a IS I I 4 4 0 * * S * I S I S S * I I I I I S III * S S I I * S * 4** III SI. I S The present invention provides a refuse container having enhanced blast resistance having a body formed from an extruded plastic material and a base connected thereto.

In a first aspect, the present invention provides a refuse container having enhanced blast resistance, which comprises a body formed from an extruded first plastics material having high fast fracture resistance and a base formed from a second plastics material, the body and the base being fused together by means of an electrofusion element.

It is very surprising that a refuse container having satisfactory blast resistance can be manufactured using plastic materials, but it has been found that certain plastic materials having high fast fracture resistance have sufficient strength to withstand a 2 kg Semtex charge, which is a recognised requirement for such containers. It has further been found that such plastics materials when tested to *destruction, tend to fail by ductile failure, such that the dispersal of shrapnel fragments is much reduced.

Preferably the fast fracture resistance of the extruded first plastics material is as high as possible, preferably at least 6kJ.m2, and more preferably at least 7kJ.m2, when measured by iSO 17281 at im/sec at 23 C.

Most preferably the fast fracture resistance of the first plastics material is at least 8kJ.m2.

* * * 4 4 4 * * * I 14 * V I V I 4 1 * I * * I S - * 4 I 4 1 4 * III III.44 1 Suitable extruded first plastic materials for the body of the container include fusible polymeric materials, for example, olefinically unsaturated polymeric materials and polyolefins such as polyethylene, polypropylene, polybutylene, and higher olefinic polymers; copolymers of ethylene, propylene and butylenes with each other and with other olefinically unsaturated monomers, olefinically unsaturated aromatic polymers, such as polystyrene and styrene copolymers; and polymers and copolymers of vinyl monomers such as ethylene vinyl acetate copolymers, and such like materials. Block copolymers and polymer blends of polymerised monomers of any of the abovementioned polymers are also included. A particularly suitable polymeric material is polyethylene, and such materials are the preferred polymeric material for use in the present invention.

The grade of polyethylene chosen, that is to say, high density, medium density, low density, or linear low density, will depend upon the particular application and the blast resistance required. Preferred grades of polyethylene for use in the present invention comprise those meeting the requirements of at least one of pressure pipe specifications prEN 12201-1, prENl22Ol-2, prENl555-l and prENl555-2 is. The grade of polyethylene known as PE100 is especially preferred. Any other suitable equivalent grade of polyethylene may, of course, also be used. Crosslinked polyethylenes such as PEX and PEXO can also be used, although the degree of cross- linking should not be so high as to preclude the joining of the base of the container to the body by electrofusion bonding.

I * I I

I I I I II I I I I

* . I I I I I - I. I I I S * I. IS. r I I I IfS III III S The body of the container is preferably cylindrical and can, for example, have an inner diameter of from 150 to 600 mm and a height of from 300 to 1600 mm. The wall thickness of the body is preferably from 16 to 60 mm, and most preferably from 20 to 45 mm.

The base of the container is preferably flat and provided with an upstanding lip adapted to be electrofused to the body. The second plastics material of the base can be the same or different from the first plastics material of the body, but is preferably the same. Preferred second plastic materials for the base include polyolefins, and especially polyethylene. The base preferably has a thickness of from 16 mm to 60 mm, more preferably from 20 mm to 45 mm. The upstanding lip can be sized so as to fit within the body, or to extend around the body and can be provided with one or more electrofusion elements to make the fusion connection between the body and the base.

In another embodiment, the upstanding lip can have the same diameter as the body of the container and a separate electrofusion coupler can be placed around a joint region between the body and the base of the container. In this embodiment, for ease of assembly, it may be convenient firstly to butt weld the lip on the base to the abutting edge of the body and remove the weld bead before positioning the electrofusion coupler therearound. The electrofusion coupler, matched in size to the body and the base, can comprise an electrofusion element, which can be, for example, an electrical resistance wire or an induction element, embedded in a fusible plastics matrix material. The electrofusion * * . S S * * S S S ** S S * * *

S S I S S S S S S

* * * * S S S S** * S I S I I S S * S.. 555 ISS S coupler can be sized so as to fit within the container or to extend around the body, as desired. The fusible plastics matrix material can comprise any of those previously enumerated, but is preferably a polyolefin, and especially polyethylene.

The plastics materials of the body and the base of the container can also comprise other plastics additives giving desired properties to the container. Thus, for example, the plastics materials can contain fire retardants, flame retardants and inhibitors so that the container can more readily withstand the effect of lighted cigarettes and other burning smoking materials thrown therein. Since the containers will often be disposed in out-door environments, the plastics materials can also usefully comprise antioxidants, and UV stabilisers.

If desired, the refuse container can be provided with an inner basket into which the refuse is deposited, and which can be removed in order to empty the container.

The container can also be provided with retaining means for securing the container to the ground or an adjacent structure. For example, the container base can be provided with lugs having holes for bolts or other retaining means.

Embodiments of refuse containers in accordance with the invention will now be described by way of example only with reference to the accompanying Drawings, in which: S S S * * * I I IS I * I I S

I I I I I I I S

* I I I I I I 115 * S I * S I 105 IS. ISS S S Figure 1 shows a first embodiment of a refuse container in accordance with the invention in sectional side elevation, in which the body and the base are connected by a separate electrofusion coupler; Figure 2 shows a second embodiment of a refuse container in accordance with the invention in sectional side elevation, in which the base is provided with an electrofusion element and the body fits within the base; and Figure 3 shows a third embodiment of a refuse container in accordance with the invention in sectional side elevation, in which the base is provided with an electrofusion element and the base fits within the body.

Referring firstly to Figure 1, the refuse container illustrated generally at 1 comprises a cylindrical body 2 and a base 3. The body 2 is formed by extruding a pipe of PE100 polyethylene and cutting the pipe to the appropriate length. The base 3 is formed by injection moulding a PE100 polyethylene. The base is provided with an upstanding cylindrical lip 4, which is the same diameter as the body. An electrofusion coupler 5 surrounds the base and the body. The electrofusion coupler 5 comprises a fusible polymeric matrix material 6 and an electrofusion resistance element 7. The electrofusion resistance element 7 is a helically wound wire having terminals (not shown) for connection to a suitable source of electric power. The base 3 is provided with lugs 8, 9 having boltholes 10, 11 whereby the refuse container 1 can be anchored to the ground.

S S * * S S * S S S *S S S t S S * S * S S S S S S * S I S S S S 455 * . S S S * * S Is. ISO ** 5 In assembling the refuse container, tcie abutting surfaces of the cylindrical body 2 and the base 3 are first lightly butt fused together at 12 and the electrofusion coupler 5 is then disposed about the body and base as shown. The electrofusion element 7 is energised and a fusion bond formed between the body and the base. The presence of the electrofusion coupler thickens the body wall and adds a further reinforcement to the refuse container at the junction of the base and the body, which would otherwise be its weakest point. It is found in practice that in preferred embodiments of the refuse container of the invention the body when tested to destruction fails by ductile failure and the additional wall thickness and reinforcement provided by the electrofusion coupler further improves its performance in this respect.

Turning now to Figure 2, there is shown a further embodiment of a refuse container according to the invention, illustrated generally at 20, in which the base of the refuse container is provided with an integrally moulded electrofusion element 21. Other components have the same reference numerals as in Figure 1. In the embodiment of Figure 2, the body 2 of the refuse container 20 is slightly larger in diameter than the lip 4 on the base, such that the lip is an interference fit in the body. The electrofusion element 21 is integrally moulded into the base 3, and is disposed on the surface of the lip 4 adjacent the inner surface of the body 2.

When the electrofusion element 21 is energised the lip 4 and the body 2 are electrofused together.

* * 0 S S S * S S S 00 * * * * S * S S S * S S S S * S S S S S S SOS * . * * 0 * S * * a.. II. *5* 0 S Referring to Figure 3, there is shown a still further embodiment of a refuse container according to the invention, illustrated generally at 30, in which again the base of the refuse container is provided with an integrally moulded electrofusion element 31. Other components have the same reference numerals as in Figure 1. In the embodiment of Figure 3, the body 2 of the refuse container 30 is slightly smaller in diameter than the lip 4 on the base 3, such that the body is an interference fit within the lip of the base. The electrofusion element 31 is integrally moulded into the base 3, and is disposed on the surface of the lip 4 adjacent the outer surface of the body 2. When the electrofusion element 31 is energised the lip 4 and the body 2 are electrofused together.

The reader!s attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification

(including any accompanying claims, abstract and drawings), may be replaced by alternative features * e * * * a S I ** * * a S S * S * * * I a * * * * * * * S S *31 a * * * * S * S * S.. 55. **. 5 0 serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features

disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

* . . * S S * . S S S. * * * * S * S S S $ * S S S * S * * * * S *** * . *

S S S * * * Sm. S.. **. * S Claims 1. A refuse container having enhanced blast resistance, which comprises a body formed from an extruded first plastics material having high fast fracture resistance and a base formed from a second plastics material, the body and the base being fused together by means of an electrofusion element.
2. A container according to claim 1, wherein the fast fracture resistance of the extruded first plastics material is at least 6 kJ.m3 when measured by iSO 17281.
3. A container according to claim 1 or 2, wherein the extruded first plastics material is a polyolefin.
4. A container according to claim 3, wherein the polyolefin is polyethylene.
5. A container according to claim 4, wherein the polyethylene is PE100 pipe grade material.
6. A container according to any one of the preceding claims, wherein the body is cylindrical and has an inner diameter of from 150 to 600 mm and a height of from 300 to 1600 mm.

* * I S S S * S S S IS S S S * * I I * * S S * S * e I * 5 * S * I S I S S * *.. *5. .I* * *
7. A container according to any one of the preceding claims, wherein the body has a wall thickness of from 16 to 60 mm.
8. A container according to any one of the preceding claims, wherein the base of the container has an upstanding lip adapted to be electrofused to the body.
9. A container according to any one of the preceding claims, wherein the second plastics material is a polyole fin.
10. A container according to claim 9, wherein the second plastics material is polyethylene.
11. A container according to claim 8, wherein the upstanding lip is sized so as to fit within the body, or to extend around the body, and is provided with one or more electrofusion elements adapted to make a fusion connection between the body and the base.
12. A container according to any one of claims 1 to 10, wherein a separate electrofusion coupler comprising the electrofusion element is disposed around a joint region between the body and the base of the container.

* S * * . S * * a * *. * * I * 0 * I 0 S S S S I I * S S S * I I 5.0 * S S I I S S * a.. II. 155 I S
13. A container according to claim 12, wherein the electrofusion coupler is disposed* around abutting edges of the body and the lip of the base.
14. A container according to claim 12 or 13, wherein the electrofusion coupler comprises an electrofusion element embedded in a fusible plastics matrix material.
15. A container according to claim 14, wherein the fusible plastics matrix material is polyethylene.
16. A container according to any one of the preceding claims, which is provided with an inner basket into which the refuse can be deposited, and which can be removed in order to empty the container.
17. A container substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
18. A refuse container comprising a fast fracture resistant plastics material substantially as hereinbefore described.