A METHOD OF SEVERING ADHESIVE STRIPS

Abstract: Adhesive strips severed in specific lengths are used for many purposes, such as for sealing can lids and for self-adhesive handles on packages. Such strips were previously severed from supply strips of the same width as the desired strip. The invention is directed to severing the strips from a supply strip (11) whose width is substantially equal to the length of the desired strips. Particularly with a view to making handles, the supply strip may on its way to the severing cutter (17, 18) be provided with a longitudinal central fold causing the handle, upon application thereof to a package, to flatly engage the package until it is to be used.

Description: A method of severing adhesive strips The many known devices and machines used for unwinding adhesive tape and/or applying adhesive tape are all designed to work with strips which are unwound in the longitudinal direction and which are thus severed trans¬ versely to the unwinding direction by cuts forming end edges on the strip cut off. This prior art involves the use of high unwinding rates causing problems with strip bursts and control of the strip. Moreover, the strip length which can be accommodated on a supply roll is so limited that frequent exchange of the roll is necessary, which is done by complicated, automatic roll exchangers. The invention concerns a method of severing adhesive strips and its object is to provide such a method which in comparison with the prior art, enables an improved ratio of unwinding rate to production rate and the use of supply rolls with strip material for several production units. This object is achieved in that the severing is effected from a supply strip, whose width is significantly greater than the width of the desired strip, by cuts forming side edges on the latter. When, as is usually the case in practice, the cuts are made at right angles to the side edges of the supply strip, as stated in claijn 7, each severed strip just requires an unwinding movement corresponding to the width of the strip, which is in most cases many times as small as its length. If the cuts are made obliquely with respect to the edges of the supply strip, the length of the cut strips will be greater than the width of the supply strip, and a correspondingly longer unwinding movement per cut strip is therefore required. If the strips are to be used e.g. for sealing the lid of cans or the like, it is expedient that they have a non-adhesive end portion which can easily be gripped when the strip is to be torn off. Such an end portion can be provided in a simple manner by carrying out the method as stated in claim 2. When the cut strips are to be used as carrier handles the supply strip should preferably be subjected to such treatment as is stated in claim 3, so that the handles will get a non-adhesive central portion and two adhesive end portions in a known manner. Claims 4, 5 and 6 define three ways of effecting the stated treatment. Of course, a supply roll of finished handle material may also be used. A known machine for making handles is shown and described in the NO B 131 330. In this machine a paper strip whose width is equal to the length of the non-adhesive central portion of the handle is advanced in a direction perpen¬ dicular to an adhesive strip, which is conventionally advanced in the longitudinal direction of the cut strips. This operation thus requires two separate web advancing mechanisms and control means to ensure proper positioning of the two strips with respect to each other. When the handle is to be applied to a package so that it forms a free arc over the package, this arc will impede the further handling, e.g. stacking in cartons or on pallets. In automatic plants a great arc will involve a risk of damage to or tearing off of the handle. This drawback can be obviated by carrying out the method as stated in claim 8 as the ironed fold causes the handle to flatly engage the package until it is gripped. If the handle material is of such a nature that the fold tends to rise and widen, it may be kept in place by application of an adhesive strip, as stated in claim 9, or by the application of a slightly adhesive layer. The invention will be explained more fully below with reference to the drawing, in which fig. 1 is a schematic and perspective view of an apparatus for performing the method of the invention, fig. 2 shows means for performing a special embodiment of the method of the invention, fig. 3 shows a can with a sealing strip manufactured in this manner, fig. 4 illustrates a known method of making carrier handles, fig. 5 shows the making of carrier handles by the method of the invention, figs. 6 and 7 are schematic and perspective views of devices for performing their respective embodiments of the method of the invention, and figs. 8 and 9 show box-shaped packages with applied handles made by the apparatus shown in fig. 6 and in fig. 7 , respectively. In fig. 1 the numeral 10 designates a supply roll of strip material 11, on whose underside a layer of adhesive is applied. The material is pulled off the supply roll by means of a motor driven pair of rollers 12, from which it runs over a tightening roller 13 and an additional O?*.PI roller 14 to an advancing assembly, which, in the embodi¬ ment shown, consists of two sets of jaws which each comprise two pairs 15 and 16 and are disposed at their respective side edges of the web of material. One jaw pair in each set is stationary and the other is reciproc- able in the direction of the web, and the material is advanced in a known manner by alternate opening and closing of the pairs of jaws in reverse order. Thus, the material is advanced stepwise to a cutter consisting of a fixed upper knife 17 and a movable lower knife . 18. If the web of material is sufficiently rigid, the jaw assembly might perhaps be replaced by a pair of intermittently operating rollers. The tightening roller 13, which is movable up and down as indicated by a double arrow 19, provides for suitable tightening of the web and can control the velocity of the pull-off rollers 12 in a generally known manner. The width of the cut strip can be varied by changing the advancing step length of the web. Fig. 2 shows a part of an apparatus similar to the one shown in fig. 1 with a tightening roller 13 and a guide roller 14 for a web 11 of material, but the apparatus is here supplemented with a folder 20 which is placed at one side edge of the web and folds an edge strip 21 in against the underside of the web coated with adhe¬ sive. The folding is completed in that the edge portion passes between a pair of rollers 22 which are spring loaded in a manner not shown. Severing of such a web of material with a side fold provides an adhesive strip which lends itself to use in cases where the strip has to be relatively easy to tear off, e.g. as shown in fig. 3 for the sealing of the lid 23 on a can 24, where the side fold here forms a readily accessible, non- adhesive grip 25 on the strip here designated by 26. Fig. 4 shows a carrier handle 27 consisting of a self- adhesive strip whose central portion is covered by a piece of paper 28. Such a carrier handle can, as indicated, be made in a known manner, as indicated, by cutting from a supply roll 29 of self-adhesive strip material on whose adhesive side pieces of paper 28 are placed in spaced relationship. Fig. 5 shows a corresponding carrier handle 27 made according to the invention by cutting from a supply roll 30 of self-adhesive strip material whose central eb is coated with a paper strip 31 on the adhesive side. As will be seen, the strip supply has a width equal to the length of the handle cut off. Instead of using a supply roll of finished handle material, said material can be made during feeding to the cutter, e.g. as shown in fig. 6 by means of an apparatus like the one shown in fig. 1 with a pair of pull-off rollers 12, a tightening roller 13, a guide roller 14 and a cutter 17, 18. In addition to the supply roll 10 of finished strip material 11 whose underside is coated with an adhesive, there is provided a second supply roll 32 of a paper strip 31 which is advanced by the pull-off roller 12 on the adhesive underside of the strip 11 tq form a strip of handle material of the same type as the one shown in fig. 5. Fig. 8 shows a handle strip 27 applied to a box-shaped package 33 so as to form an arc over the package. A further development of the apparatus of fig..6 is shown in fig. 7 and also has supply rolls 10 and 32 of an adhesive strip 11 and a paper strip 31, respectively, pull-off rollers 12 and a tightening roller 13. Ho ever, instead of a single guide roller 14 it has o rollers 34, which each extend across about half the strip web 11 and which form such an angle with each " other that they affect the two web halves with a power component directed against the centre of the web to form a central fold 35, which increases in the feed direction, on the combined web of material here designated by 37. Two additional, inclined rollers 36 have the opposite effect and serve to stabilize the fold formed by the rollers 34 when the fold has reached a predetermined size. The two pairs of rollers 34 and 36 thus coact in forming a longitudinal central fold 38 on the web 37. The fold 38 is ironed against the web by a pressure roller 39, and if the web material is not of such a nature that the fold automatically remains in this position, it can be kept in it by means of an additional adhesive strip 40 of slight adhesiveness supplied from a supply roll 41. In fig. 9 a handle 42 cut from the folded web of material 37 is shown as applied to a box-shaped package 43. As. will be seen, the fold 38 causes the handle to flatly engage the top side of the package instead of forming an upwardly extending arc like in fig. 8. That the handle is thus kept close to the package diminishes the risk of damage under possible subsequent automatic handling of the parcel and facilitates the stacking of the parcels on pallets or in cartons. When the handle is to be used, a slight pull in it makes the adhesive strip 40 release its grip so that the handle can be lifted and a suitable space is formed between the handle and the package. Webs for the making of handles may also be produced in other ways than by coating the central portion of an adhesive strip with a paper strip as described in the foregoing. For example, instead of the paper strip a powdered or liquid material which neutralizes the adhesiveness may be applied by spraying. Another possi¬ bility is to apply the glue during the feeding of the strip from the supply roll to the cutter and just apply glue at the points where it is needed, viz. along the edges. Devices for application of glue and devices for spraying neutralizing powders or liquids are well-known and will not be described here.

Claims: P A T E N T C L A I M S 1. A method of severing adhesive strips, c h a r a c t e r i z e d by effecting the severing from a supply strip, whose width is significantly greater than that of the desired strip, by cuts forming side edges on the latter. 2. A method according to claim 1, c h a r a c t e r i z e d by folding an edge portion of the supply strip in against the adhesive side of the strip prior to severing. 3. A method according to claim 1, c h a r a c t e r i z e d by subjecting the supply strip to such treatment as will give it a non-adhesive central portion and two adhesive edge portions prior to severing. 4. A method according to claim 3, wherein a strip of . self-adhesive sheet material is used which is fed from a supply roll to a cutter by means of a pair of feed rollers, c h a r a c t e r i z e d by feeding a strip of cover material from a second supply roll and causing said strip to cover the central portion of the self-adhesive sheet strip. 5. In the method according to claim 4 the change that a powdered orliquid material neutralizing the adhesive¬ ness is sprayed on to the central portion of the self- adhesive sheet strip during feeding to the cutter. 6. A method according to claim 3, c h a r a c t e r i z e d by using a non-adhesive supply strip on which an adhesive is applied along the edges during feeding to the cutter. 7. A method according to any of the preceding claims, c h a r a c t e r i z e d by making the cuts at right angles to the side edges of the supply strip. 8. A method according to any of claims 3 - 7, c h a r a c t e r i z e d by producing a fold on the non-adhesive central portion of the strip prior to sever- ing and ironing said fold against the strip. 9. A method according to claim 8, c h a r a c t e r i z e d by applying a relatively narrow adhesive strip to hold the fold against the supply strip.

Inventors: LARSEN MOGENS DROST, LARSEN, MOGENS, DROST
Applicants: LARSEN MOGENS DROST, LARSEN, MOGENS, DROST
Application year: 1984
Main classification: B65H35
IPC codes: B65B61, B65D5, B65H35, B65H37, B65H45