EP0750561B1

EP0750561B1 - Taped bag supply and method of manufacturing

Info

Publication number: EP0750561B1
Application number: EP95911417A
Authority: EP
Inventors: Gordon Ernest Baxter
Original assignee: WR Grace and Co Conn; WR Grace and Co
Current assignee: Cryovac LLC
Priority date: 1994-03-18
Filing date: 1995-03-17
Publication date: 1998-05-20
Anticipated expiration: 2015-03-17
Also published as: DE69502595D1; ES2117858T3; AU1899395A; WO1995025664A1; GB9405399D0; DE69502595T2; GB2288583A; EP0750561A1

Description

The present invention relates to the production of a strip of taped, imbricated bags, for use in packaging. Specifically the present invention relates to forming a strip of such bags with the tape of either or both ends of the strips formed with a bag-free, non-adhesive leader.

It is known to use a strip of bags when packaging, for example, blocks of cheese (as disclosed in, for example, US-A-3,331,182; US-A-2,664,238; and US-A-3,698,547).

A typical known strip is formed by affixing an array of imbricated bags to the adhesive surfaces of a pair of carrier tapes arranged spaced-apart and side-by-side, preferably affixing the bags to the tapes at their open ends. Use of such a strip is a convenient way of handling bags in a packaging process.

To arrange such a strip on a suitable machine it is necessary to insert the tapes through guides such as eyelets, pins or rollers used to position the tapes in their path through the machine. To achieve this it is undesirable to simply leave the tape at the ends of the strip bare because the adhesive tape surfaces become unmanageable by accidentally sticking to things. This is a particular problem when the strip is transported from one place to another, typically layered (or flaked) in a box. Normally to mask the adhesive, scrap material is attached across the two tapes, using as the scrap either a length of the bag material which has not been cut and welded into bags or else a number of extra bags deliberately affixed, perhaps with a reduced overlap.

According to one aspect of the present invention there is provided a plurality of imbricated bags on a pair of side-by-side tapes each having an adhesive face to which the bags are affixed, characterised in that at either or both ends of the plurality of bags each tape extends beyond the last bag with a leader without exposed, tacky adhesive but able to be threaded around and through components of a bag loading machine, and in that said leaders are arranged as a length of tape folded with said adhesive face innermost and affixed to itself.

According to another aspect of the present invention there is provided a method of arranging such a product on a machine for packaging items in said bags, said machine having guides for aligning said tapes in their path through the machine, said method including threading said leaders through said guides.

According to yet another aspect of the present invention there is provided a method of making a strip of bags comprising affixing a succession of imbricated bags on a pair of side-by-side tapes each having an adhesive face to which the bags are affixed, characterised by folding, at either or both ends of the strip, each tape lengthwise with said adhesive face innermost to affix it to itself, such that each tape extends beyond the last bag with a leader rendered without exposed, tacky adhesive.

In order that the present invention may be better understood the following description is given, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a cross sectional views lengthwise along the front end of a bag strip;

Fig. 2 is a top view of the arrangement shown in Fig. 1;

Fig. 3 shows the preferred apparatus for forming the leader;

Figs. 4 and 5 are, respectively, top and side views of the tape formed with a leader according to the present invention.

Fig. 6 shows a view of the apparatus shown in Fig. 3 taken along line A.

Figs. 1 and 2 show a bag strip 1 with the bags 3 imbricated (or shingled) so as to expose a portion 4 at the open end of each bag 3 which is affixed to the adhesive face 5 of two tapes 2. It would be possible to use a different number of tapes. The tapes are formed with a leader 10 where the adhesive face 5 has been de-activated.

As shown in Fig. 3, to form the strip 1 of bags 3 a succession of imbricated bags 3 and a pair of parallel tapes 2 are fed along

respective paths

7 and 9 in respective directions B and A. The bags 3 thus come into contact with the adhesive face 5 of each tape 10 at a nip 8, whereby the bags 3 are affixed to the tape 10. As shown in Figs. 1 and 2, a leader 10 is formed on the tape. This may be done at either or both ends of the strip.

On reaching the end of a strip 1, the stream of bags 3 along path 7 is interrupted to form a bag-free leader 10 of each tape 2 and after an appropriate length of tape 2 has been led (bag-free) to form a leader 10, the tapes 2 are cut to separate one strip 1 of bags 3 from the next.

The leader does not have any exposed tacky adhesive surfaces. The strip 1 is continuously flaked into a box for transportation leaving the leaders 10 uppermost. Because the leaders are non-adhesive, the box may be transported without the ends of the tape 2 becoming affixed to anything. Furthermore, because the tapes are non-adhesive, the strip 1 may be more easily handled, thereby facilitating loading of the strip 1 onto a packaging machine for filling the bags 3. This is quicker, resulting in increased productivity without wastage of bags 3.

The packaging machine may be arranged such that, after the bags 3 are detached from the tapes 2 for filling, the tapes 2 are stuck together, adhesive face 5 to adhesive face 5, as disclosed in US-A-3698547, whereby no tacky face remains exposed facilitating disposal.

The leaders are particularly advantageous if a strip 3 is formed with leaders 10 at both ends. When loading a strip of bags 3, this allows the front leaders 10 of one strip 1 to be attached to the rear leaders 10 of the preceding strip 1, thereby allowing a continuous flow of successive strips 1 into the packaging machine. This simplifies the process of loading a new strip onto the packaging machine, because it is simply drawn through by the preceding strip 1 and saves time, in particular, by avoiding the need to thread the tapes 2 through guides in the packaging machine.

To attach the leaders 10 together in this way, it is possible to adhere one tape to the next using the adhesive face 5. However, if the adhesive is not strong enough or if neither leader is tacky, then the leaders 10 may alternatively be knotted together or else a separate linkage may be used. It may be necessary to adjust the attachment to maintain the tapes 2 in alignment and prevent the bags 3 crinkling.

There is a variety of ways of forming the leader, each of which may be achieved by suitable components arranged around the path 9 of the tape 2 upstream of the nip 8 to be activated when a strip 1 of predetermined length has been produced.

One way of forming the leader 10 is to fold the adhesive face 5 onto itself. This may be done with a fold line lengthwise along the centre 13 of the tape 2, with the adhesive surface 5 innermost so that the adhesive surface 5 bonds to itself. This creates a leader 10 as shown in Figs. 4 and 5 which is half its original width, thereby facilitating loading of the strip on a packaging machine because the leader 10 is stronger and also easier to insert through eyelets used to maintain the strip 1 in its path.

An apparatus used to fold each of the tapes 2 is shown in Figs. 3 and 6 and principally comprises a respective block 20 formed with an elongate V-shaped groove 21 arranged lengthways along, and therefore opposing the path 9 of the tape 2 on the opposite side of the tape 2 from the adhesive face 5. The block 20 is further formed with a parallel-sided slot 22 which opens into the V-shaped groove 21 at the apex of the groove 21, the slot 22 extending along the entire length of groove 21. It will be understood that the opening comprising the groove 21 and slot 22 has a constant cross-section along its length parallel, in use, to the path 9 of the tape 2.

To form the leader 10, the blocks 20 are driven quickly towards the respective tapes 2 by means of pneumatic ram 24 in the direction C. The relative motion of the respective tape 2 into the groove 21 causes the tape 2 to fold along its length. This is particularly effective if the tape is of a material which has been orientated longitudinally. The tape 2 is further driven laterally into the slot 22 by (i) the motion of the block and (ii) the supporting of the respective tape by a fixed axis small diameter roller 30 (Fig. 3) just upstream of the position along the path 9 each block occupies when driven down by the pneumatic actuator 24. In conjunction with the thickness of the tape 2, the width of the slot 22 is selected so that the slot 22 is able to grip the tape 2 sufficiently tightly to cause the adhesion of the inner face folded along the centre 13 of the tape 2.

Advantageously, immediately downstream of each slot 22 in its block 20 there is provided a respective pair of nip rollers 23 to press together even more firmly the two halves of each tape 2 emerging from the slots 22, thereby affixing the two halves of the tape more firmly together. Preferably the rollers 23 are provided with bevelled lower corners 25 to prevent the tape 2 fouling on entering into the nip.

The mechanism just described is a particular effective way of forming the leader 10 and results in the tape being accurately folded lengthwise along its centre 13.

Alternatively, the end of the tape may be folded about a line perpendicular to its length with the adhesive face 5 innermost so as to bond the end of the tape 2 back onto itself, thereby creating the leader 10.

Instead, the tape beyond the end bag 3 of the strip 1 may be twisted or rolled around a line along the length of the tape 2 so that the adhesive face 5 of the tape 2 bonds the tape into a cylindrical leader 10. This forms a lace-like leader which is particularly useful when loading a tape onto a packaging machine.

Claims

A plurality of imbricated bags (3) on a pair of side-by-side tapes (2) each having an adhesive face (5) to which the bags (3) are affixed,
characterised in that at either or both ends of the plurality of bags (3) each tape (2) extends beyond the last bag with a leader (10) without exposed, tacky adhesive and in that said leaders (10) are arranged as a length of tape folded with said adhesive face (5) innermost and affixed to itself.
A plurality of imbricated bags according to claim 1, wherein said plurality of bags (3) is arranged layered in a box.
A plurality of imbricated bags according to either one of the preceding claims, wherein said tapes (2) are formed of a longitudinally oriented material.
A plurality of imbricated bags according to anyone of the preceding claims, wherein said tapes (2) are folded lengthwise.
A plurality of imbricated bags according to any one of the preceding claims, wherein each tape (2) at each end of said plurality has a said leader (10).
A method of arranging pluralities of imbricated bags, each plurality being constructed and arranged as defined in claim 5, on a machine for packaging items in said bags (3), the method comprising attaching the rearward leaders (10) of one plurality of imbricated bags (3) and the forward leaders (10) of the succeeding plurality of imbricated bags (3) to enable the succeeding plurality of imbricated bags (3) to be led through the machine by the said one plurality of imbricated bags (3).
A method of arranging a plurality of imbricated bags, constructed and arranged as defined in any one of claims 1 to 5, on a machine having guides for aligning said tapes (2) in their path through the machine,
said method including the step of threading said leaders through said guides.
A method of making a strip (1) of bags (3) comprising affixing a succession of imbricated bags (3) on a pair of side-by-side tapes (2) each having an adhesive face (5) to which the bags (3) are affixed,
characterised by folding, at either or both ends of the strip (1), each tape (2) lengthwise with said adhesive face (5) innermost to affix it to itself, such that each tape extends beyond the last bag with a leader (10) rendered without exposed, tacky adhesive.
A method according to claim 8, wherein said tape (2) is folded by relatively driving said tape into a notch (21).
A method according to claim 9, wherein said notch is an elongate groove (21).
A method according to claim 9 or 10, wherein said notch (21) is V-shaped.
A method according to claim 11, wherein the tape is relatively driven through the notch (21) into a slot (22) extending from the apex of the V-shaped notch (21), from which slot the tape (2) emerges folded.
A method according to any one of claims 9 to 12, wherein the folded tape (2) is passed through a pair of nip rollers immediately after folding.
A method according to any one of claims 9 to 13, wherein the notch (21) is formed in a block (20) which is arranged to be driven at the tape by a pneumatic actuator (24).
A method according to any one of claims 9 to 14, wherein each tape (2) is supported on a roller (30) immediately upstream of that location along the tape path where folding occurs.