Method and device for packaging products and array of packaged products

Abstract

A method for packaging products, such as candies, the method comprising the steps of positioning the products on a first sheet which is continuously moved in a transport direction, covering the products by a second sheet which is continuously moved in the same transport direction and which is aligned substantially plane-parallel to the first sheet, and sealing together the first and second sheets near the outer edges of the individual products or grouped products by a sealing device, wherein the sealing device comprises sealing ribs extending substantially transversely to the transport direction on one side of the moving sheets, wherein said sealing ribs are being moved at the same speed as the sheets and the sealing ribs seal the first and second sheets together in between the moving products.

Claims

1. A method for packaging products comprising the steps of: placing elongated individual or grouped products spaced a pre-defined distance apart on a conveyor having a transport direction; continuously moving a bottom, uniformly planar, unshaped first sheet in the same transport direction as said conveyor; pre-shaping an upper second sheet to fit partially around said products and spaced from the first sheet prior to contacting said products, continuously moving the second sheet in the same transport direction as said conveyor; positioning the said spaced apart products on the first sheet; and, sealing the first sheet to the second sheet with a sealing device moving at the same speed as the first and second sheets and having sealing ribs extending transversely to the transport direction, said sealing ribs being disposed between said products to form a seal between said spaced apart products, wherein the second sheet is pre-shaped by engaging the second sheet with a rotating first shaping drum on one side of the second sheet and a rotating second shaping drum on the opposite side of the second sheet, wherein each of said shaping drums comprises shaping ribs protruding from the cylindrical surface of the drum and extending transversely to the transport direction of the second sheet, and wherein the shaping ribs of the first shaping drum and the shaping ribs of the second shaping drum co-operate to move between each other while contacting the second sheet.

2. The method according to claim 1, wherein at least one suction device is located on the first shaping drum between the protruding shaping ribs.

3. The method according to claim 2, wherein the at least one suction device at least partially pre-shapes the second sheet.

4. The method according to claim 1 wherein the sealing ribs protrude from the cylindrical surface of a rotating drum.

5. The method according to claim 1, wherein the sealing ribs comprise the protruding shaping ribs of the rotating first shaping drum.

6. The method according to claim 1, wherein at least the first shaping drum is positioned such that it guides the moving second sheet towards the moving first sheet.

7. The method according to claim 1, wherein the sealing device uses ultrasonic sealing to seal the first and second sheets, and wherein the ultrasonic sealing comprises co-operation between an ultrasonic welding device and the sealing ribs.

8. The method according to claim 1, wherein the first sheet comprises a rigid board or film.

9. The method according to claim 8, wherein the first sheet comprises plastic-coated cardboard.

10. The method according to claim 1, wherein the second sheet comprises a flexible foil or film.

11. The method according to claim 1, further comprising sealing the longitudinal sides of the first sheet and the second sheet together to enclose the individual or grouped products in an air-tight package.

12. The method according to claim 11, further comprising folding the longitudinal sides of the sealed first and second sheets upwards, thereby enhancing the rigidity of the air-tight packages.

13. The method according to claim 1, further comprising weakening the sealed areas between the products such that the packaged products stay attached to each other, but can be easily separated.

14. The method according to claim 13, wherein weakening the sealed areas between the products comprises perforating or scoring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be illustrated with reference to the drawings, wherein:

(2) FIG. 1 shows a schematic perspective view of a packaging device;

(3) FIG. 2 shows a schematic side view of a detail of the packaging device of FIG. 1;

(4) FIG. 3 shows a further schematic side view of a detail of the packaging device of FIG. 1;

(5) FIG. 4 shows a perspective view of an array of packaged products.

DETAILED DESCRIPTION OF THE INVENTION

(6) With reference to FIGS. 1, 2 and 3 the packaging device has a first roll of card board 1 having a plastic coating on at least one side and a second roll of plastic film 2. The elongated candy bars 3 are placed transversely on a first endless conveyor 4. A separation device 5 has a barrier which moves up and down at regular intervals for spacing the candy bars 3 a pre-defined distance apart.

(7) The second conveyor 6, the third conveyor 7, the fourth conveyor 8, the fifth conveyor 9, as well as the card board 1 all move at the same speed, which is larger than the speed of conveyor 4 in order to accommodate the larger mutual distance of the candy bars.

(8) The plastic film 2 is led between a co-operating rotating shaping drums 10, 11. Both drums 10, 11 have protruding shaping ribs 12, 13 which during rotation are moved between each other like a gear unit, thereby corrugating the plastic film 2 into the desired shape. The drum 10 has flexible suction cups 14 between its ribs 12 which hold the pre-shaped film by a vacuum action force.

(9) The pre-shaped film 2 is placed on top of the moving candy bars 3 by the drum 10 while they are at the same time being transferred by the conveyor 6 onto the coated side of moving cardboard 1. In this manner the candy bars 3 are enclosed in the cardboard 1 and the pre-shaped plastic film 2. When the ribs 12 are at their lowest point 2 they push the plastic film 2 onto the cardboard 1, where the plastic film 2 is welded on the coated side of cardboard 1 by a first ultrasonic welding device 22, which co-operate with ultrasonic welding means present in the sealing ribs 12. In this manner a series of interconnected tubes is formed, each tube comprising a candy bar. By changing the opening time of the separation device 5 also two or more candy bars 3 can be grouped together and enclosed in a single tube thereby.

(10) Subsequently the transverse seals between the candy bars 3 are perforated or scored by a rotating drum 24 having scoring or perforating ribs 15. Then the ends of the film 1 which extend from the sides of the candy bars 3 are pushed down by two further ultrasonic sealing devices 16 and sealed to the cardboard 1, whereby the candy bars 3 are enclosed inside the cardboard and plastic film in an airtight manner. At this stage the candy bars 3 form an endless array of interconnected packaged products. The separation drum 17 separates the products into arrays 19 of for instance six candy bars each by means of cutting ribs 18.

(11) The array 19 of candy bars 3 as shown in FIG. 4 thereby has a cardboard layer 1 on the bottom side and a shaped plastic film layer 2 on the top side which is sealed onto the cardboard layer 1 in between the candy bars 3. These transverse seals have scores or perforations 20 so that individual products can be easily torn off, without breaking the seal. Both sealed longitudinal sides 21 of the package are folded upwards, giving the array 19 such rigidity that it can subsequently be treated as a box. The array 19 can be shipped to and exposed in shops, and sold to the public, without the need to enclose it in a further layer of plastic, as is the case with prior art packaging methods of candy bars.