WO1994024003A1

WO1994024003A1 - Carrier strap for a container

Info

Publication number: WO1994024003A1
Application number: PCT/GB1994/000665
Authority: WO
Inventors: Karl-Heinz Lichius
Original assignee: British United Shoe Machinery Limited; Usm España, S.L.; Dvsg Holding Gmbh
Priority date: 1993-04-13
Filing date: 1994-03-30
Publication date: 1994-10-27
Also published as: AU6380494A; DE9406032U1; GB9307545D0

Abstract

A carrier strap for a container, e.g. a box of washing powder, is made of a recyclable material so that the container and carrier strap can be recycled. The material of the carrier strap is made by a wet-laid process from cellulose fibres together with a suitable binder, preferably a water-soluble natural binder. The cellulose fibres may include up to 30 % recycled fibres.

Description

CARRIER STRAP FOR A CONTAINER

This invention is concerned with a carrier strap for a container, e.g. a box for washing powder, and also with such a container having a strap.

Boxes of washing powder tend to be made from cardboard or other recyclable material and are, at least in the heavier sizes, provided with a carrier strap which is riveted to the cardboard box. In general such straps are made of polyethylene which thus renders the whole box unsuitable for recycling.

It is thus the object of the present invention to provide an improved carrier strap for a container, e.g. a box for washing powder, which is itself recyclable, thereby rendering the whole container recyclable also.

The invention thus provides, in one of its several aspects, a carrier strap for a container, e.g. a box for washing powder, said strap being of a recyclable material made by a wet-laid process from cellulose fibres together with a suitable binder in a ratio of between 70:30 and 95:5 parts by weight.

By using a strap made of a recyclable material, in particular a material as referred to in the last preceding paragraph, it will be appreciated, the whole container can now be recycled, requiring only the removal of the small metal rivets, which can take place in a conventional manner during the reprocessing of the material, e.g. by magnets.

The cellulose fibres used in the material of the carrier strap preferably comprise softwood fibres having an average length in the range 2.0 to 3.5mm; if desired, furthermore, the cellulose fibres may include up to 30% recycled fibres.

Although the binder may comprise a synthetic binder, e.g. styrene butadiene rubber, polyvinyl acetate, polyvinyl alcohol, ethylene vinyl acetate and acrylic rubber, which, because of the relatively small quantities used, will not render the material of the carrier strap non-recyclable, preferably the binder comprises a natural binder, in particular a water-soluble natural binder, e.g. casein starch or carboxymethyl cellulose (CMC) . In this way, although the tensile strength of the material of the carrier strap will not be detrimentally affected if wetted, nevertheless the use of a water-soluble binder will facilitate the recyclability of the product. Again, if desired, a combination of natural and synthetic binders, may be used, e.g. SBR together with starch.

The length and width of the strap will vary according to the size of the container, but in general the length of the strap will be preferably in the range 375 to 500mm, and its width 10 to 35mm. Moreover the thickness (gauge) of the strap may vary, according to the container size, between 0.6 and 2mm. To ensure adequate performance as a carrier, furthermore, the weight is

2 preferably in the range 300-1400 g/m . In a preferred embodiment, for a 3kg container, the length is 390mm, the

2 width 15mm, the gauge 0.9mm and the weight 520 g/m .

The invention further provides, in another of its several aspects, a container, e.g. a box for washing powder, made of a recyclable material and having a carrier strap as set out above.

There now follows a detailed description, to be read with reference to the accompanying drawings, of a carrier strap for a container, e.g. a box for washing powder, and of such a container having a carrier strap. It will be appreciated that this carrier strap and this container have been selected for description merely by way of non-limiting example.

In the accompanying drawing is shown a perspective view of a container, e.g. a box for washing powder, having a carrier strap. The container 10 shown in the drawing is typically a 3kg box of washing powder made in a conventional manner from a recyclable cardboard. Secured by rivets 12 to opposite side faces of the container 10, and extending in an arc over and being spaced from the upper surface of the container, is a carrier strap 14 which is also of recyclable material. The box with its carrier strap is thus recyclable, it being required only to remove the metal rivets 12 in a conventional manner during the reprocessing of the material.

To this end the carrier strap 14 is made by a wet-laid process using cellulose fibres and a suitable binder, the ratio of fibres to binder being between 70:30 and 95:5 parts by weight. In a preferred embodiment the ratio is 90:10 parts by weight.

The cellulose fibres are preferably a mixture of softwood fibres together with up to 30% by weight of recycled fibres; the fibres have an average length in the range 2.0 to 3.5mm, preferably an average of 3.2mm. The recycled fibres may be constituted by conventional commercially available waste fibre material.

In the material now being described the binder comprises a water-soluble natural binder; preferred binders are starch, casein or CMC. In another embodiment, however, a synthetic binder, e.g. a styrene butadiene rubber latex, may be used, but in such a case low quantities only should be included, since a high quantity of synthetic binder would have a detrimental effect on the recyclability of the product. Other suitable synthetic binders are polyvinyl acetate, polyvinyl alcohol, ethylene vinyl acetate and acrylic rubber. In a still further embodiment, moreover, a combination of natural and synthetic binders may be used, e.g. styrene butadiene rubber and natural starch in a 70:30 parts by weight ratio. The weight of the material thus produced is in 2 the range 500-800 g/m , in the particular case (for a 3kg

2 container) 520 g/m , and its gauge is in the range of

0.6-2.00mm, in the particular case, for a 3kg container, approx. 0.90mm.

The length of the carrier strap 14 is in the range 375 to 500mm and its width 10 to 35mm. For the 3kg container shown, typically the length of the strap is 390mm and its width 15mm.

It has been found that with such materials the breaking load (tensile strength) is in the range 300 to 80ON when dry. For the 15mm wide carrier strap referred to above, the dry breaking load was typically in the order of 40ON. Moreover, after complete immersion in water for a period of 15 minutes the breaking load was found still to exceed 10ON.

In producing the material from which the carrier strap is made, the wet-laid process provides for relatively large widths of material to be manufactured, typically 1.5m, and this material is then cut progressively into strips of the appropriate width and of course also of the appropriate length.

Claims

Claims:

1. A carrier strap for a container, e.g. a box for washing powder, said strap being of a recyclable material made by a wet-laid process from cellulose fibres together with a suitable binder in a ratio of between 70:30 and 95:5 parts by weight.

2. A carrier strap according to Claim 1 wherein the cellulose fibres comprise softwood fibres having an average length in the range 2.0 to 3.5mm.

3. A carrier strap according to Claim 1 wherein the cellulose fibres include up to 30% recycled fibres.

4. A carrier strap according to Claim 1 wherein the binder comprises a water-soluble natural binder.

5. A carrier strap according to Claim 1 wherein the binder comprises a synthetic binder, e.g. styrene butadiene rubber, polyvinyl acetate, polyvinyl alcohol, ethylene vinyl acetate or acrylic rubber.

6. A carrier strap according to Claim 1 wherein the binder comprises a combination of synthetic and natural binders in a ratio in the order of 70:30 parts by weight.

7. A carrier strap according to Claim 1 wherein the weight of the material is in the range 500-800 g/m2.

8. A carrier strap according to Claim 1 wherein the length of the strap is in the range 375 to 500mm, preferably 390mm, and its width 10 to 35mm, preferably 15mm.

9. A carrier strap according to Claim 1 wherein the gauge is 0.6-2.00mm, preferably 0.9mm.

10. A container, e.g. a box for washing powder, made of a recyclable material and having a carrier strap according to Claim 1.