IE83932B1 - Method and apparatus for packaging trays of pots - Google Patents

Description

METHOD AND APPARATUS FOR PACKAGING TRAYS OF POTS FRUITS OF IRELAND (R&D) LIMITED METHOD AND APPARATUS FOR PACKAGING TRAYS OF POTS This invention relates to a method and apparatus for packaging trays each holding a plurality of pots containing, for example, jam.

It is known to package trays of pots by flow wrapping with plastics film. A typical tray of pots is shown in The tray 10 is rectangular in plan view and is molded from a plan and end views in Figs. 4A and 4B respectively. plastics material t$%provide a number of buckets or recesses 12, in this cage a gx5 array. Each recess 12 is adapted to receive a respective pot 14 of jam. The pots 14 are also molded fromdplastics material, and sealed in The body of the pot conforms substantially to the shape of the conventional manner with a peel—back foil lid. recess so that each pot is snugly received in its recess (only two pots are shown in Figs. 4A and 4B although obviously in practice all recesses will be filled).

In the flow wrapping process a plastics film is drawn from a continuous roll and wrapped around successive trays on a conveyor to enclose each in a sealed, close- fitting film envelope. However, such packaging has experienced considerable problems in the market place.

It will be understood that with plastics trays and plastics film there is a limit to how tightly one may wrap the film around the tray. If the film is too tight the tray will bend and if it is too loose then effectively there is no wrapping support from the film.

Even with the optimum wrap pressure there are problems, since wholesalers and retailers often present the wrapped trays to the public not in a horizontal configuration but in a vertical configuration, i.e. with the tray standing on one side. This can lead, after a short time, to the tray bending and some jam pots being dislodged from the recesses in the tray. This results first in an unsightly presentation of product and, second, to the jam pots bursting if in purchase and subsequent transporting they had any other products stacked upon them. It will be readily appreciated that burst jam pots cause both wholesaler/retailer and the customer to take a poor View of the product leading to customer complaints and an avoidance of the product in the future.

According to the present invention there is provided a method of packaging trays each containing a plurality of pots, the method comprising conveying the trays successively past a wrapping station and, at the wrapping station, (a) wrapping a film, drawn from a continuous roll, over the top surface and around the opposite side edges of each tray, (b) sealing the opposite edges of the film together below each tray to form a shallow tube of film containing the tray, (c) sealing the top and bottom of the film tube together between each adjacent pair of trays along a line transverse to the direction of conveyance to enclose each tray in a sealed envelope of film, and (d) severing the film between adjacent trays along the said transverse line of sealing so that each tray is separated from the rest each in its own sealed envelope, the method further comprising placing at least one spot of adhesive generally centrally on the top surface of each tray before it reaches the wrapping station and, at the wrapping station, maintaining the film out of Contact with the adhesive for a certain distance of travel of the tray.

The invention further provides an apparatus constructed to perform the above method.

Fig. l is an end view of an apparatus according to the embodiment of the invention; Fig. 2 is a side view of the apparatus of Fig. 1; Fig 3 is a perspective view of the wrapping station of the apparatus of Fig. 2; 4A and 4B are plan and end Figs. (previously described) views respectively of a tray containing pots of jam; Figs. 5A to 5E are side views of a tray of pots at successive stages of wrapping by the apparatus of Figs. 1 to 3; Fig. 6 is a perspective View of a tray of pots after the application of adhesive but prior to wrapping; Fig. 7 is a perspective view of a tray of pots after wrapping; and Fig. 8 is a fragmentary cross-section through a wrapped tray of pots.

Referring to Figs. 1 to 3, the machine there shown is a modification of a commercially available flow wrapping machine sold under the name [MODEL NAME] by [MANUFACTURER]. The conventional operation of the machine will first be briefly described, followed by the modification according to the embodiment of the invention.

In the conventional machine, empty trays 10 are placed on a conveyor 16, the trays are filled with pots 14 SA), (Fig. and the filled trays are conveyed by the conveyor 16 successively past a wrapping station 18. At the wrapping station the trays pass under a fixed frame 20 which is spaced above and substantially horizontal to the conveyor 16 so as to be positioned just above the top surface of the trays SC). (see also Fig. The frame 20 is supported by a vertically adjustable slider 22.

A continuous length of plastics film 24, drawn from a roll 26, travels down towards the conveyor 16 and passes under the frame 20. From there the film 24 travels along in the forward direction of the conveyor A to SE) (the direction of the arrow in Figs. at substantially the same speed as the trays 10. a of the film, The longitudinal centre portion whose overall width is more than twice that of the trays, extends over and along the top surfaces of the trays, while the opposite longitudinal edge portions 24b of the film extend downwards beyond each of the opposite side edges of the trays (Fig. 5C).

Beyond the forward end of the conveyor 16, i.e. to the right of the frame 20 as seen in Fig. 5C, the opposite longitudinal edges 24c of the film 24 below the trays 10 are drawn together between a pair of heated pinch rollers (not shown). These seal the opposite longitudinal edges c together below the trays 10 and thereby enclose the trays in a shallow or flattened tube of film with a seam running along the bottom of each tray. The pinch rollers not only seal the edges of the film together but also impart a certain lateral tension to the film as it is drawn around the edges of the trays, so that the tube of film is close fitting about the trays. The pinch rollers also draw the film 24 from the roll 26.

Next, the trays 10 pass to a sealer/cutter (also not shown) which first heat seals the top and bottom of the film tube together between each adjacent pair of trays along a line transverse to the direction of conveyance to enclose each tray in a sealed envelope of film (Fig. 5D), and then severe the film between adjacent trays along the transverse line of sealing so that each tray is separated SE). a label 28 is applied to the top surface of the (Fig. SE) from the rest each in its own sealed envelope (Fig.

Finally, film envelope on each packaged tray 10.

The operation of the machine is controlled by a processor contained in a control box 30, Fig. 2, and various operating parameters may be set on a control panel 32.

As mentioned above, the machine and its operation as thus far described is a commercially available machine and further details can be ascertained from an examination of such machine if desired.

In order to mitigate the problem described above, that is, of the film and the top surface of the tray separating too much so that pots fall out of their recesses in the tray, the known machine is modified in two ways.

First, an adhesive dispenser 34 (Figs. 2 and SE) is positioned centrally above the conveyor 16 at a location upstream of the wrapping station 16.

A sensor (not shown) senses the leading edge of each tray 10 as it passes a fixed point on the conveyor and a timer triggered thereby causes the dispenser to eject at least one, and in this embodiment two, spots of adhesive 36 onto the top surface of the tray before it reaches the wrapping station 16. The adhesive spots 36 are located at or near the centre of the top surface of the tray 10 as seen in Figs. 4A and 6.

Secondly, two rigid, substantially mutually parallel rods (Figs. 1, 3 and 5C) are rigidly supported at their rear ends by respective stepped brackets 40 and project freely in the forward direction of the conveyor 16 into the gap between the frame 20 and the top surfaces of the trays 10. This constrains the film 24 to pass over the rods 38 when it is moving beneath the frame 20, and thus keeps the film out of contact with the adhesive spots 36 until the film moves beyond the free forward ends of the rods.

The purpose of the rods 38 is to prevent the film 24 from engaging onto the adhesive spots 36 until the adhesive has partially cured (become tacky), and also to allow the motion of the film to become stabilised with respect to (It will be appreciated that when the film first passes under the the motion of the underlying tray. frame 20 there will inevitably be some relative movement, particularly in the lateral direction, between the film and tray). Thus the film meets the adhesive "cleanly" so that unsightly smudging/smearing of the adhesive is minimised. The label 28 covers final packaged tray.

The invention is not limited to herein which may be modified or from the scope of the invention. the adhesive spots in the the embodiment described varied without departing

Claims (7)

1. A method of packaging trays each containing a plurality of pots, the method comprising conveying the trays successively past a wrapping station and, at the drawn from a wrapping station, (a) wrapping a film, continuous roll, over the top surface and around the opposite side edges of each tray, (b) sealing the opposite edges of the film together below each tray to form a shallow tube of film containing the tray, (c) sealing the top and bottom of the film tube together between each adjacent pair of trays along a line transverse to the direction of conveyance to enclose each and (d) film between adjacent trays along the said transverse tray in a sealed envelope of film, severing the line of sealing so that each tray is separated from the rest each in its own sealed envelope, the method further comprising placing at least one spot of adhesive generally centrally on the top surface of each tray before it reaches the wrapping station and, at the wrapping station, maintaining the film out of contact with the adhesive for a certain distance of travel of the tray.

2. A method as claimed in claim 1, wherein the film travels from the roll down towards the conveyor and passes under a fixed member which is spaced above and substantially parallel to the conveyor, and wherein the film is maintained out of contact with the adhesive by at least two substantially mutually parallel rods each supported at its rear end and projecting freely in the forward direction of the conveyor into the gap between the said member and the conveyor, the rods. the film passing over

3. A method of packaging trays each containing a plurality of pots, substantially as described herein with reference to the accompanying drawings.

4. A tray containing a plurality of pots packaged by the method claimed in claim 1, 2 or 3.

5. An apparatus for packaging trays each containing a plurality of pots, the apparatus comprising means for conveying the trays successively past a wrapping station, and means at the wrapping station for (a) wrapping a film, drawn from a continuous roll, over the top surface and around the opposite side edges of each tray, (b) sealing the opposite edges of the film together below each tray to form a shallow tube of film containing the tray, (c) sealing the top and bottom of the film tube together between each adjacent pair of trays along a line transverse to the direction of conveyance to enclose each and (d) film between adjacent trays along the said transverse tray in a sealed envelope of film, severing the line of sealing so that each tray is separated from the rest each in its own sealed envelope, the apparatus further comprising means for placing at least one spot of adhesive generally centrally on the top surface of each tray before it reaches the wrapping station and means at the wrapping station for maintaining the film out of Contact with the adhesive for a certain distance of travel of the tray.

6. An apparatus as claimed in claim 5, wherein the film travels from the roll down towards the conveyor and passes under a fixed member which is spaced above and substantially parallel to the conveyor, and wherein the means for maintaining the film out of Contact with the adhesive comprises at least two substantially mutually parallel rods each supported at its rear end and projecting freely in the forward direction of the conveyor into the gap between the said member and the conveyor, the film passing over the rods.

7. An apparatus for packaging trays each containing a plurality of pots, substantially as described herein with reference to the accompanying drawings. F. R. KELLY & CO., AGENTS FOR THE APPLICANTS