GB2276950A

GB2276950A - Check-weighing sliced product in a packaging line

Info

Publication number: GB2276950A
Application number: GB9404371A
Authority: GB
Inventors: Richard Payne
Original assignee: Thurne Engineering Co Ltd
Current assignee: Thurne Engineering Co Ltd
Priority date: 1993-04-08
Filing date: 1994-03-07
Publication date: 1994-10-12
Anticipated expiration: 2014-03-07
Also published as: DE4409908A1; GB9307460D0; GB2276950B; GB9404371D0

Description

2276950 1 PACKAGING LINE When producing and packaging groups of slices of

product, for example groups of slices of meat or cheese, it is necessary to ensure that the weight of every packaged group falls within certain pre-determined limits. These limits are set by law and' by commercially acceptable standards.

It is well known to use various control systems which are designed to vary the thickness and/or number of slices which form each group to try and ensure that each packaged group is of the required weight. Unfortunately, it is not always possible to use such a control system, and even when using such a system errors may occur, especially for groups of slices which are cut from the leading end of a log of product.

Conventionally, each and every group of slices is weighed on a checkweigher downstream of the slicing machine to determine whether the group is of an acceptable weight, and if the group is outside the acceptable limits, the group is separated from the other groups, off the packaging line, to allow correction of its weight. The weight signals from the check-weigher are often fed back to the slicer to help control the slice number and/or thickness.

The over-weight or under-weight groups of slices are fed along a separate conveyor to a make-weight station where they are weighed again and then full or part slices r 2 are added or removed manually to correct the weight of the group. At -a suitable time, when a gap is available in the main packing line, the corrected group is manually placed in the main packaging line.

Such systems are disadvantageous as groups of slices which are diverted along the separate conveyor, corrected, and replaced in the main packaging line, are susceptible to being distorted and torn, and the individual slices forming the group are liable to be displaced thus destroying the arrangement of slices in the group. In addition, after the under-weight or over-weight groups of slices have been corrected, it is necessary to wait for a suitable gap in the main packaging line before the group can be returned to the packaging line. During all this time and especially as a result of the extra handling steps, the group of slices is exposed and is susceptible to microbial attack.

According to the present invention, a packaging line for producing packaged groups of slices of product comprises:

slicing machine; check-weigher downstream of the slicing machine to weigh a group of slices of product; packaging machine including a product-receiving f ilm for use in vacuum packaging or gas flushed packaging the groups of slices; an indicator adjacent the packaging machine; and, control means to monitor the progress of each group of slices of product from the check-weigher to the product- 3 receiving film, and to control the indicator to indicate each of the groups of slices of product on the productreceiving film whose weight is outside a pre-determined range.

The packaging line according to the present invention is advantageous over prior art packaging lines as any groups of slices which are cver- weight or under-weight do not leave the packaging line, and therefore these groups of slices are not distorted or displaced. Further, none of the groups of slices are delayed in their journey to the packaging machine, and this minimises the risk of microbial attack. Further still, the packaging line according to the present invention only weighs each group of slices once before they are packaged, whereas the prior art systems require a check-weigher to determine whether each group of slices is within the accepted weight range, and a second check-weigher at the make-weight station to re-weigh the group of slices to determine whether additional slices must be added or slices removed.

The indicator is preferably in the form of coloured lights which have one colour for indicating an under-weight group, and another colour indicating an over-weight group.

Alternatively, the indicator has the form of a light bean with a different spot shape, size or location to indicate under-weight and over-weight groups. Preferably, the indicator can indicate the extent to which the group is below or above the required weight so that the operator knows how much of a slice to add or remove from the group.

4 Preferably, the indicator is located below the product-receiving film. In this case, the productreceiving film may be either transparent or translucent so the indicators are visible through the f ilm, or may be opaque with the indicators arranged to project light onto the film.

Preferably the sliccr simultaneously slices a plurality of groups of slices, for example by slicing a plurality of logs of product. In this case, the packaging line preferably includes means to supply only one group at a time to the check-weigher.

The packaging line preferably includes marshalling is means to deliver a number of groups of slices of product simultaneously to the product-receiving film. The productreceiving film preferably forms the top film of the final packaging. In this way, any slices or parts of slices which are added to or removed from the group of slices are added to or taken from the bottom of the final package so that they or any disturbance is not visible, and therefore the package does not lose its neat appearance.

The packaging line preferably includes a check-weigher downstream of the packaging machine to ensure that all groups leaving the packaging line are within the pre determined weight range.

An example of a packaging line according to the present invention will be described and contrasted with the prior art with reference to the accompanying drawings, in which:- 1 11 Figure 1 shows an example of a prior art packaging line; and

Figure 2 shows an example of a packaging line according to the present invention.

Figure 1 shows a conventional packaging line. A block of product is sliced by a slicing machine 1 to produce a group of slices. This growp of slices is conveyed to a check-weigher 2 where the group is weighed, and the weight of the group is compared to the required weight range. If the group's weight is within the required range, the group is conveyed to packaging machine (not shown). If the weight of the group is outside the required range, the group is diverted away from the main conveyor along a reject conveyor 7 to a make-weight station 9. At this point,, the group is re-weighed. and slices of product are added or removed from the group to bring the weight of the group within the required range. The group is then discharged from the make-weight station 9 along a conveyor 10 where it is held until it can be re-introduced onto the main conveyor when there is a suitable gap to progress to the packaging station.

An example of a packaging line according to the present invention is shown in Figure 2. In this example, a slicing machine 21 simultaneously slices three logs of product to produce three groups of slices. Each of these groups of slices are individually weighed by a checkweigher 22 before being discharged onto a conveyor 23. A marshaller upstream of the check-weigher 22 allows only one 6 group of slices to proceed to the check-weigher 22 at a time. The weight of each group is stored in a memory of a controller 30. All of the groups of slices of product are conveyed along the packaging line, none are rejected or diverted. The groups are conveyed downstream, where they are marshalled by a marshaller into an array of groups 26. This array of groups 26 is transferred onto a receiving film 29 of a packaging machine. As the groups of slices are conveyed to the packaging machine, their progress is monitored by the controller. The controller associates the weight of each group of slices measured by the checkweigher with the group as it is conveyed.

An indicator 31 adjacent the packaging machine projects a light onto each of the groups of slices depending on the weight of the group stored in the memory. The projected light is dependent upon the weight of the group, if the group is under- weight, a blue light is shone onto the group indicating that additional slices should be added. If the group is over-weight, a red light is shone onto the group, indicating that slices should be removed from the group.

The indicator is not limited to indicating which of the groups are overweight and under-weight by displaying different colours, but may instead indicate by a variation in the size, location or shape of a projected light beam. Additional colours, sizes, locations, shapes or numbers of beams of light can be used to indicate the extent to which the group is under-weight or over- weight. for example to m 7 indicate to the operator whether to add or remove a whole, half or quarter slice to the group.

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Claims

C L A I M 8

1. A packaging line f or producing packaged groups of slices of product comprising:

slicing machine; check-weigher downstream of the slicing machine to weigh a group of slices of product; packaging machine including a product-receiving f ilm f or use in vacuum packaging or gas f lushed packaging the groups of slices; an indicator adjacent the packaging machine; and, control means to monitor the progress of each group of slices of product from the check-weigher to the productreceiving film, and to control the indicator to indicate each of the groups of slices of product on the productreceiving f ilm whose weight is outside a pre-determined range.

2. A packaging line according to claim 1, in which the indicator is in the form of coloured lights which have one colour for I ndicating an under-weight group, and another colour indicating an over-weight group.

3. A packaging line according to claim 1, in which the indicator has the form of light beams of different spot shape, size or location to indicate under-weight and over- weight groups.

4. A packaging machine according to any one of the preceding claims, in which the indicator indicates the i 9 extent to which the group is below or above the required weight. -

5. A packaging line according to any one of the preceding claims, in which the indicator is located below the product-receiving film.

6. A packaging line according to claim 5, in which the product-receiving f ilm is transparent, or translucent so the indicators are visible through the film, or is opaque with the indicators arranged to project light onto the film.

7. A packaging line according to any one of the preceding claims, in which the slicer simultaneously slices a plurality of logs of product, and in which the packaging line includes means to supply only one group at a time to the check-weigher.

8. A packaging line according to any one of the preceding claims, which includes marshalling means to deliver a number of groups of slices of product simultaneously to the product-receiving film.

9. A packaging line according to any one of the preceding claims, in which the receiving film forms the top film of the final packaging, so that any slices or parts of slices which are added to or removed from the group of slices are added to or taken from the bottom of the final package.

10. A packaging line according to any one of the preceding claims, which includes a check-weigher downstream of the packaging machine to ensure that all groups leaving the packaging line are within the pre-determined weight range.

11. A packaging line substantially as described with reference to Figure 2 of the accompanying drawings.

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