Method and apparatus for handling linerless label material

Abstract: Linerless labels (24) are produced by feeding a tape (11) having a release coated face (14) and an adhesive face (13) to a hardened anvil vacuum cylinder (21), utilizing a non-stick circumferential surface feed roll (18). A knife blade (27) on a cutting cylinder (26) is rotated into contact with the tape at the anvil cylinder to cut the tape into linerless labels, and release liquid is applied (at 29) to the blade after each cut. From the anvil cylinder the labels are deposited on a plurality of spaced conveyor tapes (32) of circular cross section with the adhesive faces contacting the conveyor tapes. A vacuum chamber (34) assists in holding the labels on the conveyor tapes. The release coat faces of the labels conveyed by the conveyor tapes may be heated and then printed with hot melt ink from an ink jet printer (36). The labels are separated from the conveyor tapes using a peeler roll (39) and non-stick stripper rings (38), and then immediately contact a moving web (31) or other elements to which they are to be applied, with the label and web passing through nip rolls (40) to activate the pressure sensitive adhesive.

Description: Because they are less expensive and more labels can be provided in a roll than conventional labels with release liners, linerless labels are achieving increased popularity. Equipment for applying linerless with rewettable or thermal sensitive adhesives to a wide variety of moving elements (such as substrates, bottles, or packages) is fairly common, such as shown in U.S. patents 2,492,908 and 4,468,274. However, the application of pressure sensitive adhesive labels to moving elements while known (e.g. see U.S. patent 4,978,415) is uncommon, and does not have the versatility to apply the labels to all sorts of moving elements, such as envelopes, webs, bottles, cans, and packages. Also, the linerless label typically formed utilizing the prior art equipment for applying pressure sensitive linerless labels leaves a skeletal web which must be disposed of. An article in Modern Packaging, vol 33, 1960, pages 201-207, describes a system for applying linerless labels to packages in a continuous production line, and forms the basis for the preamble to the method of claim 1 and to the apparatus of claim 5. It does not include or make provision for printing on the labels before application to the packages. According to the present invention, there is provided a method of applying linerless labels to moving elements in a continuous process line, the labels comprising a substrate having a release coated face and an opposite pressure sensitive adhesive coated face, comprising the steps of: feeding tape comprising a substrate with a release coated face and an opposite pressure sensitive adhesive coated face from a supply to a cutting position with the substrate being moved from the supply to the cutting position by contact with a non-stick circumferential rotating surface of a feed roll; cutting the tape into individual labels at the cutting position using a continuously rotating anvil vacuum cylinder and knife blade with the release coated face of each label in contact with the anvil vacuum cylinder; and continuously applying the labels to moving articles, characterised by transferring the labels from the anvil vacuum cylinder to a conveyor with the adhesive faces in contact with the conveyor and printing on the release coated face of each label while it is being transported by the conveyor to the applying position and before it is applied to a moving article. In another aspect the invention provides apparatus for handling linerless labels in a continuous process line comprising: means for mounting a supply of linerless label tape having a release coated face and an adhesive face; means for substantially continuously feeding the tape from said supply to a cutting means, said feeding means comprising a feed roll provided with a non-stick circumferential surface, and means for directing the tape into contact with said feed roll so that the adhesive face of the tape engages the non-stick circumferential surface of said feed roll; cutting means for cutting the tape into individual linerless labels; the cutting means including a rotatable anvil vacuum cylinder for contacting the release coated side of the labels and a knife; means for continuously applying individual linerless labels to moving articles; and characterised by conveyor means arranged to receive the labels from the anvil cylinder and convey them to the applying means with the adhesive sides of the labels in contact with the conveyor means, and by printing means mounted in association with said conveyor means for printing indicia on the release coated faces of the labels prior to their application to the moving articles. The conveyor includes conveyor tapes which are spaced in a direction transverse to the direction of conveyance of labels thereby, and a vacuum chamber assists the adhesive from the labels in maintaining the labels in position on the conveyor tapes during conveyance. The conveyor tapes are typically substantially circular in cross section so as to present a minimal area for engagement with the label adhesive. Where, as typical, the labels are moved into contact with moving envelopes, the labels and envelopes pass through nip rollers whereby the pressure sensitive adhesive is activated. According to a preferred feature of the invention, an ink jet print head may also be provided in association with the conveyor tapes for printing indicia on the release coat face of the labels just prior to removal of the labels from the conveyor tapes. If the ink is a hot melt ink, a heated platen is preferably provided over the release coat faces of the labels to heat them prior to printing so that they are receptive to the hot melt ink. It is the primary object of the present invention to provide a simple yet effective apparatus and method for applying linerless labels to moving elements. This and other objects of the invention will become clear from a detailed description of the invention, and from the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side schematic view of exemplary apparatus according to the present invention; FIGURE 2 is a more detailed side view of a revised form of the transport mechanism of the apparatus of FIGURE 1, diagrammatically showing labels being placed on and peeled from conveyor tapes; FIGURE 3 is a top plan view of the conveyor tapes and stripper rings of the transport mechanism of FIGURE 2; FIGURE 4 is a is an end view at the stripper rings of the components of the transport mechanism of FIGURE 3 shown in association with a label; and FIGURE 5 schematically illustrates the label tape alone and after severing and placement on individual envelopes. DETAILED DESCRIPTION OF THE DRAWINGS Exemplary apparatus for handling linerless labels, according to the present invention, is shown generally by reference numeral 10 in FIGURE 1. The first element of the apparatus 10, which is conventional, comprises means for mounting a supply of linerless label tape (typically in roll form) 11, such means preferably comprising a conventional friction unwind device shown schematically at 12 in FIGURE 1. The tape of roll 11 per se is conventional, and comprises a substrate, such as plastic or paper, with a pressure sensitive adhesive side or face 13, and a release material coated face 14 (which will not stick to the pressure sensitive adhesive on face 13). In the roll configuration 11 of the tape, the release coated face 14 is on the outside. A strip of tape 15 being taken off from the roll 11 passes with the release coated side 14 in contact with an idler roll 16, and then into contact with the non-stick circumferential surface 17 of a feed roll 18. The feed roll is driven by a conventional drive mechanism (not shown), and actually feeds the tape 15 to a cutting apparatus or position, shown generally by reference numeral 19 in FIGURE 1. The pressure sensitive adhesive face 13 of the tape 15 actually makes contact with the non-stick circumferential surface 17 of the feed roll 18. The non-stick surface 17 prevents adhesive build up on the feed roll 18, however it is not so slick as to prevent positive feeding of the tape 15 thereby. For example, the surface 17 may be coated with polytetrafluoroethylene may be polished metal, or may be metal coated with a conventional release coat material used on release paper. The cutting apparatus 19 includes a hardened anvil vacuum cylinder 21, rotatable about an axis parallel to the axes of rotation of the idler roll 16 and the feed roll 18. At least the circumferential surface 22 of the anvil vacuum cylinder 21 is hardened to perform an anvil function. A vacuum applied through cylinder 21 (vacuum cylinders per se are well known) holds the tape, and labels subsequently cut therefrom, on the peripheral surface 22. Cooperating with the hardened anvil vacuum cylinder 21 for cutting the tape 15 into individual labels 24 (see FIGURE 2, 4 and 5) there is provided a cutting cylinder 26 having a radially extending knife blade 27 (or radially spaced knife blades if desired). The cylinder 26 is rotatable about an axis parallel to the axis of the anvil cylinder 21, and means are provided (such as a frame) for mounting the cutting cylinder 26 adjacent the anvil cylinder 21 so that the cutting blade just barely makes contact with the hardened surface 22 of the cylinder 21. In order to prevent the knife blade 27 from sticking to the tape 15 as it is cutting the labels 24, a small amount of liquid release material is applied to the blade 27 between successive cuts. This is accomplished by the idler wiper roll 29 which is a felt roll impregnated with release material, and is mounted for rotation about an axis parallel to the axis of rotation of the cutting cylinder 26, and adjacent the cylinder 26, so that as the blade 27 is rotated away from contact with the hardened anvil surface 22 of the cylinder 21, it engages the felt and picks up a small amount of release liquid, incrementally rotating the wiper roll 29 as it does so. The cut length of the labels 24 are determined by the ratio of the feed roll 18 revolutions to cutting cylinder 26 revolutions (and number of cutting blades 27). This ratio may be changed by conventional mechanisms such as gears, single revolution clutches, or servo-motor controls. The anvil vacuum cylinder 21 transports the cut labels 24 into association with a transport mechanism, shown generally by reference numeral 30, away from the cylinder 21, ultimately into contact with moving elements, such as envelopes moving in the path 31. The transport mechanism 30 preferably comprises a plurality of conveyor tapes 32 which receive the adhesive face of the labels 24. While the adhesive on the adhesive face of the label 24 facilitates adherence of the labels 24 to the conveyor tapes 32 so that they can convey the labels in a transport direction 33 (see FIGURE 1), in order to insure that the labels stay in place until it is desired to remove them, a vacuum chamber 34 also is preferably provided. The vacuum pulls air through the spaces between the conveyor tapes 32, thereby providing a force holding labels 24 on the conveyer tapes 32. While the labels 24 are being transported in direction 33 by the conveyor tapes 32, it may be desirable to print indicia on the release coated faces 14 thereof. For this purpose an ink jet print head 36, or like structure, may be provided. If the ink jet print head applies hot melt ink, just prior to the print head 36 a heated platen 37 is preferably provided for heating the release coat face 14 of the labels 24 to make them receptive for the ink from the print head 36. Once the labels 24 have been printed and it is desired to apply them to the moving elements, such as envelopes in path 31, in addition to removing the force of the vacuum chamber 34 it is desirable to positively separate the labels 24 from the conveyor tapes 32. For this purpose, a plurality of stripper elements, such as stripper rings 38 having non-stick circumferential surfaces, associated with a peeler roll 39, are provided. After separation of the labels 24 from the conveyor tapes 32, the pressure sensitive face 13 of each label 24 is fed into contact with an envelope 47 (see FIGURE 5) in path 31, and the envelope with label applied is passed through nip rolls 40 whereby the pressure sensitive adhesive is activated to insure adherence of the label 24 onto the envelope 47 moving in path 31. A more detailed illustration of the transport mechanism 30, especially the stripper rings and conveyor tapes, is provided in FIGURES 2 through 4. For ease of illustration, the components shown in FIGURES 2 through 4 are simplified compared to those in FIGURE 1. Components in the FIGURES 2 through 4 embodiment comparable to those in the FIGURE 1 embodiment are shown by the same reference numeral only preceded by a "1". The conveyor tapes 132 transport the labels 24 in transport direction 133, and are spaced from each other -- see spaces 42 in FIGURE 3 -- in a dimension perpendicular to the direction 133. The conveyor tapes 132 preferably are substantially circular in cross section so as to provide a minimal area of contact with the labels 24. A conventional drive 43 is provided for driving the conveyor tapes 132. The vacuum chamber 134 is connected up to a vacuum pump 45 or the like, which draws air through the spaces 42 and facilitates holding of the labels 24 on the conveyor tapes 132. Where it is desirable to remove the labels 24 from the conveyor tapes 132, a separating mechanism will be provided. The separating mechanism comprises the stripper elements, preferably stripper rings, 138 which extend upwardly above the tops of the conveyor tapes 132 to deflect each label 24 away from the tapes 132, as seen in FIGURES 2 and 4. The stripper rings 138, at least the portions that will contact the adhesive faces 13 of the labels 24, are of non-stick material, such as polytetrafluoroethylene. The peeler roll 139, mounted for rotation about an axis parallel to that of the vacuum cylinder 121, is provided just above the conveyor tapes 132 and just prior to the stripper rings 138. The peeler roller 139 aids in removing the labels 24 from the conveyor tapes 132 by causing an upward bend in each label 24, thus causing it to travel in a direction that is tangent to both the peeler roll 139 and the stripper rings 138, and to be deflected by the rings 138 as illustrated in FIGURE 2. The stripper rings 138 can rotate with the drive shaft 44, or they could be loosely mounted on the drive shaft 44 so that relative rotation between them is possible. FIGURE 5 schematically illustrates the basic actions that are performed according to the method of the invention; the tape 15 being severed to form the individual labels 24, which are then applied onto envelopes 47 (or like moving elements) traveling in the path 31. The envelopes 47 may be transported individually in path 31, or may be mounted on a web. In a typical method of operation, the tape 15 is withdrawn from the roll 11 and fed by feed roll 18 into association with the cutting apparatus 19. The cutting cylinder 26 rotates to bring the blade 27 into contact with the tape 15 and the hardened surface 22 of the anvil roll 21, the vacuum cylinder 21 then depositing the linerless label 24 that has been cut from tape 15 onto the conveyor tapes 32, 132 with the adhesive face 13 of the label 24 on the conveyor tape 32, 132. Then the label 24 is printed by the ink jet print head 36, 136, and is separated from the conveyor tapes by the stripper rings 38, 138 and peeler roll 39, 139, and applied directly onto a moving envelope 47 in path 31. The label 24 and envelope 47 then move between the nip rolls 40, the pressure sensitive adhesive being activated, and, the final product produced, as seen in FIGURE 5. It will thus be seen that according to the present invention a simple yet effective method and apparatus have been provided for handling linerless labels and applying them onto moving elements. While the invention has been herein shown and described in what is presently conceived to be the most practical and preferred embodiment, it will be apparent to those of ordinary skill in the art that many modifications may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent apparatus and methods.

Claims: A method of applying linerless labels to moving elements in a continuous process line, the labels comprising a substrate having a release coated face and an opposite pressure sensitive adhesive coated face, comprising the steps of; feeding tape (11) comprising a substrate with a release coated face (14) and an opposite pressure sensitive adhesive coated face (13) from a supply to a cutting position with the substrate being moved from the supply to the cutting position (19) by contact with a non-stick circumferential rotating surface of a feed roll (18); cutting the tape into individual labels at the cutting position (19) using a continuously rotating anvil vacuum cylinder (21) and knife blade (27) with the release coated face of each label in contact with the anvil vacuum cylinder; and continuously applying the labels to moving articles, characterised by transferring the labels from the anvil vacuum cylinder to a conveyor (32) with the adhesive faces in contact with the conveyor and printing on the release coated face of each label while it is being transported by the conveyor to the applying position and before it is applied to a moving article. A method according to claim 1 characterised in that the printing is practised by ink jet printing with hot melt ink and further comprising the step of heating the release coated faces of the labels just prior to the printing. A method according to claim 1 or claim 2 characterised by the further step of applying a release liquid material to the knife blade (27) after each cut of the tape therewith. A method according to any of claims 1 to 3 characterised in that the articles to which the labels are applied comprise moving envelopes and by the further step, after application of a label to a moving envelope, of mechanically pressing the pressure sensitive adhesive coated face of the label into contact with the envelope to ensure proper adherence between them. Apparatus for handling linerless labels in a continuous process line comprising: means (12) for mounting a supply (11) of linerless label tape having a release coated face (14) and an adhesive face (13); means (18) for substantially continuously feeding the tape from said supply to a cutting means, said feeding means comprising a feed roll (18) provided with a non-stick circumferential surface, and means (16) for directing the tape into contact with said feed roll so that the adhesive face of the tape engages the non-stick circumferential surface of said feed roll; cutting means (21, 26, 27) for cutting the tape into individual linerless labels (24); the cutting means including a rotatable anvil vacuum cylinder (21) for contacting the release coated side of the labels and a knife (27); means (35, 39, 40) for continuously applying individual linerless labels to moving articles; and characterised by conveyor means (32) arranged to receive the labels from the anvil cylinder and convey them to the applying means with the adhesive sides of the labels in contact with the conveyor means, and by printing means (36) mounted in association with said conveyor means (32) for printing indicia on the release coated faces (14) of the labels prior to their application to the moving articles. Apparatus as recited in claim 5 characterised in that said conveyor means comprises tapes (32) of substantially circular cross section so as to provide minimal areas of contact with the labels. Apparatus as recited in claim 5 or claim 6 characterised in that the printing means (36) for printing on the release coated faces (14) of the labels prints with hot melt ink; and further comprising a heater (37) mounted above said conveyor means for heating the release coated faces up stream of the printing means.

Inventors: NASH THOMAS P, NASH, THOMAS P.
Applicants: MOORE BUSINESS FORMS INC, MOORE BUSINESS FORMS, INC.
Application year: 1993
Main classification: B65C9
IPC codes: B65C9