GB2241484A

GB2241484A - Wrapping silage bales

Info

Publication number: GB2241484A
Application number: GB9004779A
Authority: GB
Inventors: Kenneth Stephen Eddin Orpen
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-03-02
Filing date: 1990-03-02
Publication date: 1991-09-04
Also published as: GB9004779D0

Abstract

A method of wrapping articles particularly bales of silage 10 comprising feeding from rolls 20 and 22 to the bale 10 via a dispenser 24-30 partially overlapping films of plastics materials, the bale of silage being rotated about its longitudinal axis 12 on rollers 14 and 16 and about an axis perpendicular to the axis 12 by rotation of a table 18 on which the rollers are mounted. One film may be black and the other white whereby all white, all black or partly black/partly white wrapped bales may be produced. <IMAGE>

Description

This invention is concerned with a method of and apparatus for wrapping articles in plastics film and in particular for wrapping bales of silage.

It is the modern practice to wrap bales of silage in plastics film supplied in rolls. This preserves the silage between being cut and being used as animal fodder. Three common colours of film are used - black, white and green.

Black film blocks sunlight and thus prevents deterioration of the silage resulting from exposure to ultraviolet light but tends to cause overheating and consequent deterioration of the silage. White film, even when incorporating ultraviolet inhibitors or blockers, suffers from ultraviolet deterioration though it avoids the problems of overheating.

Green film is an attempt to retain the advantages of both black and white film but in practice is less satisfactory than either.

Another consideration in wrapping practice is the speed of wrapping as it is clearly desirable to wrap as quickly as possible while using the largest standard (i.e.

readily available) width of film.

It is an object of the present invention to provide an improved method of and apparatus for wrapping articles.

The present invention is a method of wrapping an article in plastics film comprising feeding from a dispenser to the article a pair of partially overlapping strips of plastics film while rotating the article about a first axes and providing relative rotation between the article and the dispenser about a second axis perpendicular to the first, each wrap of the pair of strips being applied to the article to overlap the previously applied wrap.

The present invention is also apparatus for wrapping an article in a plastics film comprising a support for the article, means for rotating the article about a first axis, a film dispenser, means for providing relative rotation between the film dispenser and the support about a second axis perpendicular to the first, the film dispenser being adapted to feed to the article from two rolls of plastics film a partially overlapping pair of strips of film such that each wrap of said pairs of strips on the article overlaps the previous wrap.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a diagramatic plan view of apparatus according to the present invention for wrapping a bale of silage in plastics film, and Fig. 2 is an elevation view in the direction of the arrow 11 of part of the film dispenser of Fig. 1.

Referring now to Fig. 1, a bale of silage 10 having an axis 12 is shown mounted on a pair of rollers 14 and 16 rotatable about their longitudinal axes which are parallel to the axis 12. The rollers 14 and 16 are mounted on a turntable 18 which is rotatable anticlockwise as seen in Fig.

1 about a central vertical axis. Drive means are provided to rotate the turntable and at least one of the rollers so that the bale 10 is rotated about the turntable axis and simultaneously about its own axis on the rollers 14 and 16.

If the relative speeds of the turntable 18 and the rollers 14 and 16 is correct then a film fed to the bale will on each turn or wrap overlap the film deposited on the previous wrap.

Such platforms on which a bale can be rotated simultaneously about two mutually orthogonal axes are well known in the bale wrapping art.

A dispenser 10 mounts two rolls of film 20 and 22.

Film from the roll 20 passes over a pair of stretch rollers 24 and 26 and then to a dispensing roller 28 while film from the roll 22 passes over a pair of stretch rollers 30 and 32 to the dispensing roller 28.

As seen in Fig. 2 the stretch rollers 30 and 32 are at a higher level than the stretch rollers 24 and 26 and of course the rolls 20 and 22 are mounted at the same height as their associated stretch rollers. The effect of this is that film from the roll 22 is fifty per cent overlapped by the film from the roll 20 when the two films come together at the roller 28, thus providing a combined film fifty per cent wider than either of the films on the rolls 20 and 22. This increased film width may be exploited to reduce the time taken to wrap the film around the bale 10.

Alternatively the roll 22 is black and the roll 20 is white so that the pair of films coming from the roller 28 is a white film overlapping the black. If the proper relationship is maintained between the speeds of the turntable 18 and the rollers 14 and 16 then each wrap of a pair of films from the roller 28 can be laid on the pair of films laid on the previous turn of the turntable 18 so that the black film on the bale is covered by the white film of the pair being laid. At the end of the wrapping operation however the bale has one half on which the black film layer is overlaid by the white film layer and the other half on which the black film layer overlies the white film layer, i.e. the wrapped bale is half white and half black. In this way the bale of silage is protected by the white layer against overheating and by the black layer against ultraviolet light.

The embodiments described may be modified by making adhesive those faces of the films from the rolls 20 and 22 that come together at the dispensing roller 28. The two films are thus joined at the roller 28 and the marginal surfaces where they are not overlapped are presented to adhere to the adhesive faces of adjacent turns of the film.

In a modified embodiment the turntable is not rotated but the dispenser 10 is rotated about the bale.

Another modified embodiment avoids the peculiar look of a half white half black bale by mounting one dispenser comprising the bale 20 with its associated rollers 24 and 26 on one vertical slide and the second dispenser comprising the bale 20 with its associated rollers 30 and 32 on a second vertical slide. The dispensers are interconnected and drive means is provided to move one dispenser from the upper to the lower position as seen in Fig. 2 while the other dispenser is moved from the lower position to the upper. Sensor means is provided at the bale to trigger this movement of the dispensers as each end of the bale is being wrapped. The result of this is that the wrapped bale is all white or all black except possibly for a stripe of the opposite colour where the last turn of film from the roller 28 was applied.

Claims

CLAIMS:

1. A method of wrapping an article in plastics film comprising feeding from a dispenser to the article a pair of partially overlapping strips of plastics film while rotating the article about a first axis and providing relative rotation between the article and the dispenser about a second axis perpendicular to the first, each wrap of the pair of strips being applied to the article to overlap the previously applied wrap.

2. A method as claimed in claim 1, in which the strips are of a different colour, the overlapping of the previous wraps being such that two halves of the outer surface of the wrapped article are each of substantially one colour.

3. A method as claimed in claim 1 or claim 2, in which the adjacent faces of the strips of each pair are adhesive, the overlapping of the successive wraps being such as to apply the inwardly facing free adhesive face of one wrap to the outwardly facing free adhesive face of the previous wrap.

4. A method as claimed in any preceding claim, in which the article is a bale of silage.

5. Apparatus for wrapping an article in a plastics film comprising a support for the article, means for rotating the article about a first axis, a film dispenser, means for providing relative rotation between the film dispenser and the support about a second axis perpendicular to the first, the film dispenser being adapted to feed to the article from two rolls of plastics film a partially overlapping pair of strips of film such that each wrap of said pairs of strips on the article overlaps the previous wrap.

6. Apparatus as claimed in claim 5, in which the support is rotatable about said second axis.

7. Apparatus as claimed in claim 5 or claim 6, in which said means for rotating the article comprises a pair of rollers mounted on the support and means for driving at least one of said rollers.

8. A method of wrapping an article in plastics film substantially as hereinbefore described.

9. Apparatus for wrapping an article in plastics film substantially as hereinbefore described with reference to and as shown in the accompanying drawings.