GB2096090A - Handling bulky goods or materials - Google Patents

Abstract

A method of handling bulky goods or materials 18 comprises compressing them and, whilst compressed, wrapping them about the axis of compression with stretched plastics film 16a and then removing the compression so that the film accepts a compressive load. Outline defining numbers, end covers and rigidity boards may be included with the goods or materials. <IMAGE>

Description

SPECIFICATION Material handling processes The invention is concerned with the matter of handling goods or materials which are inherently bulky but which can be consolidated to reduce their volume such as may be required, for example, to reduce transport or storqe costs.

Tne current approach to this matter is to compress the material and then bind it, such as with throw-away metal straps. This is generally satisfactory. However, the straps tend to make indentations into the goods or material they are containing and, with some goods, (such as stocks of corrugated paper blanks) the indentations may be permanent.

The strapped goods are not protected from weather or contamination, unless subsequently enclosed, and the straps themselves can be hazardous to remove and troublesome to dispose of once they are cut.

According to the present invention a method of handling inherently bulky goods or materials comprises compressing them and whilst compressed to wrap them about the axis of compression with stretched plastics film and then removing the compression and allowing the film to retain a substantial part or all of the compression.

The film could be imperforate, perforated or in the form of netting.

The wrapping could be by a film have a width stretched at least equal to the axial length of the goods or materials being wrapped, or could be by helical overlap with a film of less width than said axial length.

For handling bulky material which does not occupy a firm outline (such as a mass of fibres), outline defining members can be included against which the film is wrapped.

The well-known commercially available stretch film can be used or a film web can be selected with a low relaxation in the transverse direction.

In the invention, the film is used to provide initially a hoop and "radial" stress on the goods or materials being wrapped (that is, stresses in planes at right angles to the applied axial compressive stress) whilst having itself a longitudinal stress and subsequently, when the wrapping is completed, to provide an axial stress on the goods or materials in the line of the originally applied compressive stress whilst having itself both a longitudinal and transverse stress. The surface texture or profile of the goods enables the film to effect a grip on the goods.

The film may be given a loading in a direction transverse to its length immediately prior to the film contacting to goods or material to be wrapped.

A load of goods or material, one wrapped in accordance with the invention, may be given an additional wrapping of film (which is not essentially a stretch film) laid down in a direction, which was, the direction of the axis of compression. This would provide a safeguard against loss of retention of compression in the event that the first wrapping was locally cut, broken or otherwise weakened.

The invention is particularly suited to the handling of food containers of plain or corrugate material in flat blank form (so that they are kept clean when food is placed in them) and for hospital disposables either before use (where a high degree of sterility is required) or after use (where infection could arise) as the stretch film tends to provide a sealed surface even at the lines of overlap. Where the stretch film does not reach during wrapping, such as at the ends of a load, end covering caps can be provided prior to wrapping. The invention could also be applied to consolidated loads of textiles or vehicle tyres.

One form of apparatus for carrying out the process of the invention will now be described with reference to the accompanying drawing which is a diagrammatic elevation.

The apparatus comprises a base 10 on which are mounted an already known pallet stretch wrapping machine 11 and a compression gantry 1 2 (For convenience, the machine 11 and gantry12 have been shown as both existing in the common plane of the drawing.

In fact they lie in planes displaced about 45 to each other).

The machine 11 has a turntable 1 3 mounted on a pair of box girders 14 which also support a pillar 1 5 which carries a braked reel 1 6 of stretch film which can be progressively raised and lowered up and down the pillar. Film 1 6a is shown leaving the reel. A pallet 1 7 is shown on the turntable and a load 18 is shown on the pallet. And end cover 1 9 is provided on the top end of the load. A similar end cover could also be provided at the bottom end of the load. A rigidity board may be included below the cover 19. A rigidity board and cover at the base of the load 18 could replace the pallet 1 7. In such an arangement a fixed spacer would be provided between cover and turntable 1 3.

The gantry 12 has vertical beams 20, 21 secured to the base 10 and a cross beam 22.

The vertical beams act as guides for carriages 24, 25 which support a cross beam 26. The carriages can be moved vertically by piston/ cylinder devices 27, 28. The beam 26 supports a rotatable compression platen 29 with rounded edges 30.

In use of the apparatus, the beam 26 is lowered (to a position represented by the dash line carriage 24) so that the load 1 8 experiences compression compatible with recovery requirements. With the load held in the compression state, a helical overlap film wrapping operation is started from the bottom of the load to the top by raising the reel 1 6 whilst the load is rotated. The platen 29 is lifted as the film from reel 1 6 reaches it and the stretch film wrapping accepts the compressive load by becoming transversely strained. The reel 1 6 is then lifted a further short distance (say 10 cms) to complete the wrapping with a small overlap at the top end of the load.

The above described operation relates to the apparatus set to accept a variety of loads which may have varying perimeter sizes. For such operation the platen 29 is selected to be oversize relative to the loads.

Where a large number of loads of constant perimeter have to be wrapped the platen 29 is selected to be slightly smaller than the transverse dimension of the loads so that it always lies inboard of the perimeters and this allows the wrapping operation to be com pisted before the platen 29 is lifted.

u he wrapping cycle could be modified to introduce cross-bias or multiple layer wrapping.

The apparatus described above is capable of applying a compression of 4 tonnes to the load 18. When this load is removed from the wrapped load a small degree of relaxation may take place in the film wrapping but the film is capable of retaining, typically, a compressive loading of 2 tonnes.

The invention also has application to the wrapping on "formless" loads, that is loads which charge their radial dimensions or barrel significantly with axial compression. Such barreling could be contained or reduced by programming or controlling tension in the stretch film. Alternatively loads could be wrapped as they emerge from a containing sleeve.

Claims (7)

1. A method of handling inherently bulky goods or materials comprising compressing them and whilst compressed to wrap them about the axis of compression with stretched plastics film and then removing the compression and allowing the film to retain a substantial part of all of the compression.

2. A method according to claim 1 in which outline defining numbers are included in said goods or materials.

3. A method according to claim 1 or 2 in which the film is given a loading transverse to its length immediately prior to the film contacting said goods or material.

4. A method according to any preceding claim in which the wrapped goods are given an additional wrapping laid down in the direction of the axis of compression.

5. A method according to any preceding claim in which at least one end of the bulky goods or materials with a cover with or with out a rigidity board there below.

6. A method according to any preceding claim in which the tension in the film is programmed or controlled during wrapping to influence the ultimate shape of the wrapped goods or materials.

7. A method according to any preceding claim in which the goods or materials are wrapped as they emerge from a containing sleeve.