NL1030737C2 - Packaging machine for wrapping e.g. food products with film, contains central sealing unit for bonding together film webs in between web edges - Google Patents

Abstract

The machine (1) includes a central sealing unit (20) having one or more central sealing devices (21) designed to engage with the top and bottom packaging webs (11A, 11B) in one or more positions between the web edges, in order to bond the webs together in these positions. The machine also includes a feed (10) for supplying film-based packaging material which is used to wrap products (P) between top and bottom packaging webs. Lateral sealing units (12) on opposite length sides of the webs are used to bond the webs together along their edges. An independent claim is also included for a welding roll for use in a packaging machine, the roll being provided with a cutting edge along its periphery.

Description

PACKING MACHINE WITH CENTRAL SEALING UNIT

The present invention relates to a packaging machine for packaging products, comprising a supply for packaging material comprising S foil for enclosing the packaging products between an upper packaging web and a lower packaging web, as well as lateral sealing units arranged on either side along the packaging webs for sealingly connecting the upper and lower packaging web at least along the edges. Such a packaging machine is known in practice. The known packaging machine is suitable for use with various packaging products with various dimensions. The packaging products are always packaged one by one in the packaging material, the width of the webs of the packaging material being adjusted to the dimensions of the packaging product in question. This entails the drawback that when changing the type of packaging product, the width of the webs of the packaging material must also be adjusted over and over again. This takes place by intermediate changing of feed rolls of packaging material with the suitable width. This operation is per se time-consuming and extends the period in which the packaging machine 20 is stationary and is therefore disadvantageous in an economic sense.

The invention has for its object to provide a packaging machine of the type mentioned in the preamble which overcomes this disadvantage.

To that end, the packaging machine according to the invention is characterized in that the packaging machine comprises a central sealing unit, which is provided with one or more central sealing elements, which are adapted to engage on the upper packaging web and on the lower packaging web on one or more intermediate edges. positions for sealingly connecting the respective packaging webs at the intermediate positions.

The invention is based on the inventive insight to provide the packaging machine with a central sealing unit which is adapted for sealingly connecting the packaging webs at intermediate positions. The packaging machine can now be equipped with a roll of packaging material with a predetermined width, which is tailored to the dimensions of the largest packaging product. With the selected packaging material, smaller packaging products can now also be packaged, which are supplied in several parallel rows. Not only is the intended advantage achieved in this way that the conversion of rolls of packaging material with suitable width 1030737 "2 has become superfluous, but the packaging speed is also minimized with smaller packaging products.

According to a first practical preferred embodiment, the packaging machine according to the invention is provided with means for adjusting the position of each of the central sealing elements over at least a part of the width of the packaging webs. Thanks to the individual position-adjusting means, the position of each active central sealing element can be chosen freely, with which the setting of the packaging machine can be further optimized.

According to a practical preferred embodiment of the packaging machine 10 according to the invention, the central sealing unit comprises one or more axes located above the upper packaging web on which upper welding rolls are arranged, as well as one or more counter-axes located below the lower packaging web on which lower welding rolls are arranged, in which the upper welding rollers and lower welding rollers are arranged for pairwise collaboration.

According to a further elegant preferred embodiment, one or more of the upper welding rollers are provided with a cutting edge. Parallel rows of packaging products can now advantageously be simultaneously packaged and immediately separated. According to a further elaboration of this preferred embodiment, each welding roller is provided with at least two rings, which are arranged on either side of the cutting edge. By using rings of suitable material, the film is sealed in the packaging webs at the location of the rings, thereby preventing the film from melting. Preferably the rings comprise silicone material.

The invention also relates to a central sealing unit, as described as part of a packaging machine according to the invention.

The invention also relates to a welding roller for use in a packaging machine, which welding roller is provided with a cutting edge along the periphery. In a first preferred embodiment, the welding roller is provided with at least two rings, which are arranged on either side of the cutting edge. Preferably the rings comprise silicone material. The advantages of a welding roller according to the invention, namely the simultaneous welding and separation of foil-containing packaging material, can be advantageous in many types of packaging machines.

The invention will now be discussed in more detail with reference to the drawings, in which Figure 1 shows a schematic view of a preferred embodiment of a packaging machine according to the invention; 1030737-3

Figure 2 shows a schematic view of a central sealing unit as part of the packaging machine of Figure 1;

Figure 3 shows a schematic view of a pair of cooperating central sealing elements of the central sealing unit shown; Figure 4 shows a schematic sectional view of the treads of the central sealing elements of Figure 3; and

Figure 5 shows a schematic view of positioning means as part of the central sealing unit of Figure 2.

Figure 1 shows a schematic view of a packaging machine 1 according to the invention. In the preferred embodiment shown, packaging machine 1 is intended for packaging food products P which, for example, are supplied in three parallel rows on a conveyor belt 2 in the direction of the arrow T.

Packaging machine 1 is provided with a supply 10 for packaging material 11 comprising foil. Supply 10 consists of two shafts 10A, 10B located one above the other, on each of which a roll of foil 11A and 11B is arranged. The shaft 10A with foil 11A is located on the top side of the conveyor belt 2, while the shaft 10B with foil 11B is on the bottom side of the conveyor belt 2. The shafts rotate in opposite directions (see arrows R1 and R2) such that the packaging products P are enclosed between an upper packaging web of the foil 11A and a lower packaging web of the foil 11B.

Packaging machine 1 is provided on both sides with lateral sealing units 12, which are arranged on either side along the packaging webs for sealingly connecting the upper and lower packaging webs 11A and 11B in the longitudinal direction thereof.

For the sake of clarity, the packaging webs are not shown in unrolled condition in Figure 1. However, various packaging machines are known in the art which operate according to the principle described above with reference to Figure 1.

According to the invention, a central sealing unit 20 has been added to packaging machine 1. Sealing unit 20 is provided with one or more central sealing elements 21, which are arranged above the upper packaging web 11A and / or below the lower packaging web 11B, at one or more positions lying between the edges of the packaging webs. Sealing elements 21 are adapted for sealingly connecting the respective packaging webs at these intermediate positions. In the shown preferred embodiment, in which three rows of food products are packaged in parallel, two central sealing elements 21 are included in order to be able to package all packaging products separately.

Packaging machine 1 is further provided with an end-sealing unit 13 which, viewed in the transport direction, is placed behind sealing unit 20. End-sealing unit 13 is adapted for sealingly connecting the respective packaging webs in a transverse direction. End-sealing units suitable for this purpose are known per se in the art.

The packaging products P exiting packaging machine 1 are therefore sealed on the foil-containing packaging material on four sides or around. For the automatic control of the various components, packaging machine 1 is finally provided with a control 14.

Figure 2 shows central sealing unit 20 in more detail. Sealing unit 20 comprises a housing 22 in which a number of central sealing elements are included. By way of illustration, only one central sealing element 21 is shown in Figure 2. It will be clear that the number of central sealing elements can vary as desired. In general, the number of central sealing elements is equal to the number of rows of individually packaged packaging products P minus 1.

The central sealing unit 20 comprises shafts 23A which are located above the upper packaging web (not shown), as well as counter-shafts 23B located below the lower packaging web (not shown). These shafts serve to attach the one or more central sealing elements 21.

The central sealing unit 20 is further provided with means 40 for adjusting the position of each of the central sealing elements 21 over at least a part of the width of the packaging webs. The operation of these position setting means 40 is explained with reference to figure 5.

Figure 3 shows the central sealing element 21 in more detail. Sealing element 21 is composed of element 21A and counter-element 21B, which are of substantially identical design, but then mirrored. For the purposes of the explanation below, the sealing lid of element 21B in Figure 3 has been removed.

Element 21B comprises a guide 25 B for guiding over shafts 23 B. A guide roller 26 B is attached to the guide 25 B by means of an intermediate segment 24 B. The roller 26 B is provided with a gear that is driven by means of a belt 29 and a gear 27B on guide 25 B. Gear 27B can be driven by a drive rod 30B, which can be inserted through guide 31B into guide 25B.

Element 21A comprises a conductor 25A for conduction over axes 23A. A guide roller 26A is attached to the guide 25A by means of an intermediate segment 24A. The running roller 1030737-26A is provided with a gear wheel driven by a belt 29 and a gear wheel 27A on guide 25A. Gear 27A can be driven by a drive rod 30A, which can be inserted through aperture 31A into guide 25A.

The central sealing element 21 is shown in the operating position. The welding rollers 26A, 26BS are sufficiently close to each other in the operating position to engage on both sides on the packaging material which is passed between the welding rollers during operation of the packaging machine. The central sealing element 21 can also assume a rest position in which the welding rollers are spaced apart over a predetermined distance, such that the welding rollers do not engage with the packaging material.

All upper welding rollers 26A, or all lower welding rollers 26B, can be moved between the operating position and the rest position by displacing the segment 20A and segment 20B, respectively, in both directions of the arrow A and B. Segment 20A and segment 20B are separate movable relative to segment C, with which the height of the point of engagement on the foil is inserted. Suitable welding rollers for pairwise cooperation for sealingly sealing foil-containing packaging material are known per se in the relevant field.

The welding rollers 26A, 26B have been specially developed for use at intermediate positions in the packaging machine according to the invention.

Figure 4 shows a cross-sectional view of the treads 33A, 33B of the welding rollers 26A, 26B. The upper welding rollers 26A are provided on the tread 33A with a cutting edge 34 for cutting the film at the location of the weld ("seal"). On either side of the cutting edge 34, each upper welding roll 26A is provided with at least two rings 35 of protective material, which are partly arranged in grooves in the welding roll. The protective material ensures that the foil is sealed in the packaging webs and prevents the foil from fusing. The protective material must be heat-resistant and flexible, such that the foil is unilaterally heated at the location of the rings. An example of a protective material suitable for this purpose is silicone material. Each lower welding roller 26B is provided on the running surface 33B with two grooves 36 with which an area 33B for unilateral heating of the foil, which is situated opposite the rings 35, is defined. With this a better quality seal can be obtained.

Figure 5 shows the position adjustment means 40B in more detail. The position adjusting means 40B comprises a housing 41B mounted on shafts 42B that run parallel to shafts 23B of the lower conductor 25B of element 21B. The housing 41B is movable along the shafts 42B in the direction D, which extends substantially transversely to the conveying direction T. This movement can be realized in different ways 1030Z37 <£ 6, for example by means of a spindle 43B. Provided on the housing 41B is a protruding member, for example pin 44B, which can be clamped in an opening 3ΘΒ of conductor 25B. Pin 44B is slidable in and out of the opening 39B (along arrow E) by means of an actuation 45B. In the clamped state, housing S 41B together with conductor 25B can be moved along axes 42B in direction D to any desired position between the edges of the packaging webs.

The position adjusting means are described herein in the context of positioning of the lower sealing element 21B. Such position-adjusting means are available for each sealing element, in this example also for sealing element A. In this way the position of each of the central sealing elements can be individually adjusted over at least a part of the width of the packaging webs.

The packaging machine according to the invention is generally intended for packaging products in foil-containing packaging material. However, the invention is explicitly not limited to the described and shown embodiment. In addition to the food products mentioned in the IS, the packaging machine according to the invention can after all be used for packaging a wide range of other products. The quality of the weld can be adjusted to the demands placed on the packaging, for example airtight and / or liquid-tight. The number of parallel rows of packaging products can be optimally adjusted for each application by interposing the required number of central sealing units. All important factors can be taken into account, such as the dimensions of the packaging products, the width of the roll of packaging material in use, the residual material, the width of the conveyor belt, etc.

The present invention therefore extends generally to any embodiment that falls within the scope of the appended claims viewed in the light of the foregoing description and drawings.

1030737-

Claims (10)

A packaging machine for packaging products, comprising a supply for packaging material comprising foil for enclosing the packaging products between an upper packaging web and a lower packaging web, as well as lateral sealing units arranged on either side along the packaging webs for sealing at least along the edges 10 connecting the upper and lower packaging web, characterized in that the packaging machine (1) comprises a central sealing unit (20) which is provided with one or more central sealing elements (21) which are adapted to engage on the upper packaging web and on the lower packaging web at one or more positions lying between the edges for sealingly connecting the respective packaging webs at the intermediate positions. Packaging machine according to claim 1, wherein the packaging machine is provided with means (40) for adjusting the position of each of the central sealing elements (21) over at least a part of the width of the packaging webs. A packaging machine according to claim 1 or 2, wherein each central sealing unit (21) comprises one or more shafts (23A) located above the upper packaging web on which one or more upper welding rolls (26A) are arranged, as well as one or more located below the lower packaging web counter axes (23B) on which one or more lower welding rollers (26B) are arranged, in which the upper welding rollers and the lower welding rollers are arranged for pairwise co-operation. Packaging machine according to claim 3, wherein one or more of the upper welding rollers (26A) are provided with a cutting edge (34) along the circumference. Packaging machine according to claim 4, wherein each welding roller (26A) with cutting edge (34) is provided with at least two rings (35), which are arranged on either side of the cutting edge (34). The packaging machine of claim 5, wherein the rings (35) comprise silicone material. 7. Central sealing unit, as described as part of a packaging machine according to one of the preceding claims. 8. Welding roller for use in a packaging machine, which welding roller is provided with a cutting edge around the circumference. 1030Z3? I 9. Welding roller as claimed in claim 9, wherein the welding roller is provided with at least two rings which are arranged on either side of the cutting edge. The welding roll of claim 8 or 9, wherein the rings comprise silicone material. 5 1030737 "