INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
(51) International Patent Classification 6 : (11) International Publication Number: WO 95/256 B65B 43/12 Al
(43) International Publication Date: 28 September 1995 (28.09.
(21) International Application Number: PCT/GB95/00585 (81) Designated States: AU, BR, CA, CN, CZ, Fl, JP, KR, M
NO, NZ, RU, SG, SK, UA, US, VN, European patent (A
(22) International Filing Date: 17 March 1995 (17.03.95) BE, CH, DE, DK, ES, ER, GB, GR, IE, IT, LU, MC, N PT, SE).
(30) Priority Data:
9405399.8 18 March 1994 (18.03.94) GB Published
With international search report.
(71) Applicant (for all designated States except US): W. R. GRACE
LIMITED [GB/GB]; Northdale House, North Circular Road, London NW10 7UH (GB).
(72) Inventor; and
(75) Inventor/Applicant (for US only): BAXTER, Gordon, Ernest [GB/GB]; 8 Riversmead, St. Neots, Cmabridgeshire TE19 1HA (GB).
(74) Agent: BARLOW, Roy, James; J.A. Kemp & Co., 14 South Square, Gray's Inn, London WC1R 5LX (GB).
(54) Title: TAPED BAG SUPPLY AND METHOD OF MANUFACTURING
(57) Abstract
The present invention relates to the production of a strip (1) of imbricated bags affixed on the adhesive faces (5) of a pair of tap (2) arranged spaced apart and side-by-side. In particular, at either or both ends of the strips (1) each tape (2) extends beyond the last b with a leader (10) which is substantially without exposed, tacky adhesive. A variety of ways of forming the leader (10) are disclos including folding a length of tape (2), preferably longitudinally, with the adhesive face (5) innermost and affixed to itself. Preferably t tape is folded by relatively driving the tape (2) into a V-shaped groove (21) in a block (20), and further into a slot (22) from which the ta (2) emerges folded. Nip rollers (23) may be provided immediately downstream of the slots (22) to press the folded tape (2) together. T leaders (10) make it easier to arrange the strip of bags (3) on a machine for packaging items into the bags (3), particularly when lead (10) are arranged at both ends of the strips (1) so that the leaders (10) of successive strips may be attached together to enable one strip ( to be led through the machine by the preceding strip.
FOR THE PURPOSES OF INFORMATION ONLY
Codes used to identify States party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
AT Austria GB United Kingdom MR Mauritania
AU Australia GE Georgia MW Malawi
BB Barbados GN Guinea NE Niger
BE Belgium GR Greece NL Netherlands
BF Burkina Faso HU Hungary NO Norway
BG Bulgaria IE Ireland NZ New Zealand
BJ Benin IT Italy PL Poland
BR Brazil JP Japan PT Portugal
BY Belarus KE Kenya RO Romania
CA Canada KG Kyrgystan RU Russian Federation
CF Central African Republic KP Democratic People's Republic SD Sudan
CG Congo of Korea SE Sweden
CH Switzerland KR Republic of Korea SI Slovenia
CI Cδte d'lvoire KZ Kazakhstan SK Slovakia
CM Cameroon LI Liechtenstein SN Senegal
CN China LK Sri Lanka TD Chad
CS Czechoslovakia LU Luxembourg TG Togo
CZ Czech Republic LV Latvia TJ Tajikistan
DE Germany MC Monaco TT Trinidad and Tobago
DK Denmark MD Republic of Moldova UA Ukraine
ES Spain MG Madagascar US United States of America
FI Finland ML Mali UZ Uzbekistan
FR France MN Mongolia VN Viet Nam
GA Gabon
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.
Another way to create a leader 10 is to cut the tape level with the last bag 3 of the strip 1 and to weld to the cut end of the tape 2 a separate leader 10 which has no adhesive.
The adhesive may be chemically or physically stripped from the tape 5 to create the leader 10. Alternatively, an activatable adhesive might be used, such as a thermally activated adhesive. By synchronising the use of a heater with the formation of a strip 1, the tape 2 may be made to adhere to the bags along all the length of the strip 1 except all the leaders 10 which do not become heated.
Another way to create the leader 10 is to mask or neutralise the adhesive so that it is not tacky. As a mask, a powder may be sprayed onto the tape, or else a separate backing strip may be fed onto the adhesive layer just before the nip 8, when a leader 10 is required. Similarly, it is possible to use a tape 2 which is pre-formed with a backing layer which is removed along most of the length of the strip 1 (excluding the leader 10) prior to affixing the bags to it.