METHOD AND APPARATUS FOR APPLYING HEAT TRANSFER LABELS ONTO OBJECTS

Abstract: An apparatus (11) for decorating an object (O) with a heat transfer label. In use, an infeed conveyor (27) delivers the object (O) into the turret (13). The turret (13) rotatably advances the object (O) to the transfer station (21) where the label transfer system (19) transfers the label onto the object (O). Upon completion of the decoration of the object (O), the turret (13) rotatably advances the labeled object (OL) to the post-treatment station (25). At the post-treatment station (25), the labeled object (OL) is inflated with air and the contact heater (23) is displaced laterally into selective contact with the labeled object (OL). Upon completion of the post-treatment of the labeled object (OL), the turret (13) rotatably advances the labeled object (OL) to an outfeed conveyor which delivers the labeled object (OL) away from the turret (13).

Description: METHOD AND APPARATUS FOR APPLYING HEAT TRANSFER LABELS ONTO OBJECTS BACKGROUND OF THE INVENTION The present invention relates generally to a method and apparatus for decorating articles and more particularly to an improved method and apparatus for applying heat-transfer labels onto objects. Heat-transfer labels are well known in the art and are commonly applied onto objects, such as bottles, containers or other similar articles, to identify the particular product contained within the object. One type of heat-transfer label which is well known and widely used in the art comprises a label-carrying continuous web, such as a paper sheet, a wax release layer affixed onto a surface of the web and a transfer portion, or label, which is disposed on the wax release layer. The transfer portion comprises a protective layer affixed onto the wax release layer, an ink design layer affixed onto the protective layer and an adhesive layer affixed onto the ink design layer. Heat-transfer label decorators are well known and are commonly used in the art to apply the transfer portion of heat-transfer labels onto objects. Heat-transfer label decorators, also commonly referred to as decorator systems or decorators, typically comprise a turret for sequentially positioning the object at various application stations, a label transfer system for transferring a label from the continuous carrier web onto the desired article at a transfer station, a web transport assembly for sequentially positioning the labels on the carrier web at the transfer station and conveyors for feeding articles into to the turret before labeling and for removing articles from the turret after labeling. Heat-transfer label decorators also typically comprise a heater for post-treating the labeled object, the heater being typically positioned along the conveyor at a position located away from the turret and the label transfer system. As an example of a heat transfer label decorator which is well known in the art, in U.S. Patent No. 5,565,055, there is disclosed a method and system for decorating a round, oval or irregularly-shaped, open-ended article with a heat-transfer, wrap- around label supported on a carrier web. The system comprises a turret for positioning the open-ended article at a transfer location. The turret comprises a continuously rotating mandrel and a motor, the motor being coupled to the mandrel for continuously driving the rotation of the mandrel. The rotating mandrel is appropriately sized and shaped to be inserted into the open-ended article through the open end thereof and to follow the circumferential contour of the interior surface of the open-ended article when the open-ended article engages and rolls about the rotating mandrel. The system also includes a feed mechanism for positioning the label on the carrier web at the transfer location, the surface speed of the web matching that of the rotating mandrel. The system further includes means for transferring a label from the carrier web to the exterior of the open-ended article, the label, during transfer, pressing the interior surface of the open-ended article into engagement with the rotating mandrel in such a way as to cause the open-ended article to engage and roll about the rotating mandrel. In this manner, the surface speed of the article at any given cross-section thereof is kept constant and can be matched to the surface speed of the carrier web. The system further includes conveyor means for feeding the open-ended article to the turret before labeling and for removing the open-ended article from the turret after labeling. In use, heat transfer label decorators typically perform three principal application steps in order to properly apply the transfer portion, or label, of a heat transfer label onto an object, such as a bottle or container. As a first step, the object to be decorated and the heat-transfer label are preheated, this first step often being referred to as the preconditioning step in the art. Preconditioning is often accomplished using a pre-heater, a flame or a corona discharge which is located along the conveyor at a location spaced adequately away from the turret. Pre-heating a heat-transfer label causes the wax layer to begin to wear away, thereby creating a weakened adhesion between the transfer portion of the heat-transfer label and the paper sheet. It should also be noted that, after preheating the object to be decorated, the object is often properly orientated by an indexing mechanism prior to the second step. As a second step, the heat transfer label is subjected to heat and the adhesive portion of the label is pressed into contact with the object. As the heat transfer label is subjected to heat, the wax layer continues to melt, thereby allowing the transfer portion of the heat transfer label to transfer from the paper sheet and onto the object, this second step often being referred to as the heat-transfer application step in the art. It should be noted that the entire wax layer does not melt during the heat- transfer application step. Rather, a portion of the wax layer remains on the side of the transfer portion of the heat transfer label which is exposed to the environment. As such, the wax layer serves two principal purposes. First, the wax layer enables the label to transfer from the paper sheet to the object. Second, a portion of the wax layer forms a clear protective layer over the label. As a third step, each object which has the transfer portion of a heat transfer label applied thereto is subjected to heat by a heater at a location along the conveyor spaced adequately away from the turret, this third step often being referred to as the post-treatment step in the art. The post-treatment step is accomplished by subjecting the labeled object to jets of high temperature gas either as direct gas flame or as hot air jets to produce wax surface temperatures of about 300 °F to 400 °F for a period of time sufficient to remelt the wax coating without substantially heating the article to which the label has been transferred. Post-treating a labeled object serves a plurality of functions. First, post- treating a labeled object serves to cure the transfer portion of the heat-transfer label onto the object to ensure proper adhesion. Second, post-treating a labeled object also serves to eliminate air entrapment between the label and the object, thereby smoothing out the label and improving the overall aesthetics of the labeled object. Third, post-treating a labeled object serves to remelt the wax coating on the label. Upon cooling of the remelted wax coating through use of ambient or force-cooled air, the cooled wax layer solidifies to form a clear, smooth and glossy protective coating over the label. As can be appreciated, it has been found that, prior to the post- treatment step, the wax layer coating a labeled object creates a dulling in the label, which significantly compromises the aesthetics of the label, which is highly undesirable. As noted above, the post-treatment step is often accomplished by subjecting the labeled object to a direct gas flame, this process often being referred to as flaming in the art. The process of flaming introduces two notable drawbacks when applied to labeled objects which are constructed of thin walled, temperature sensitive materials. First, it has been found that flaming thin walled, heat sensitive objects tends to distort or melt the object due to the heat sensitivity of the materials being decorated. Second, it has been found that flaming thin walled, heat sensitive objects can create stresses which could cause cracking in the labeled object. SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel method and apparatus for applying a label onto an object so as to yield a labeled object. It is another object of the present invention to provide a method and apparatus as described above which post-treats the labeled object. It is yet another object of the present invention to provide a method and apparatus as described above which post-treats a labeled object which is constructed of a thin walled, temperature sensitive material. It is still another object of the present invention to provide a method and apparatus as described above which post-treats a labeled object which is constructed of a thin, walled, temperature sensitive material without distorting, melting or cracking the object. It is another object of the present invention to provide a method and apparatus as described above which requires a limited number of parts, which is easy to use and which is inexpensive to manufacture. In furtherance of the above and other objects to be described or to become apparent below, there is hereinafter provided an apparatus for applying a label onto an object, said apparatus comprising a label transfer system for applying the label onto the object at a transfer station to yield a labeled object, a contact heater for post- treating the labeled object at a post-treatment station, said contact heater being disposed to selectively contact the labeled object, and a turret for sequentially advancing the labeled object from the transfer station to the post-treatment station. The present invention is also directed to a method for post-treating a labeled object, comprising the steps of supporting the labeled object, and selectively contacting the labeled object with a contact heater. Various other features and advantages will appear from the description to follow. In the description, reference is made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration, specific embodiments for practicing the invention. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are hereby incorporated into and constitute a part of this specification, illustrate preferred embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings wherein like reference numerals represent like parts: Fig. 1 is a schematic top view of an apparatus for decorating an object constructed according to the teachings of the present invention; Fig. 2 is a perspective view of one embodiment of the contact heater shown in Fig.1 ; Fig. 3 is a perspective view of another embodiment of the contact heater shown in Fig. 1 ; Fig. 4 is top plan view of another embodiment of the contact heater shown in Fig. 1 ; Fig. 5 is a top plan view of another embodiment of the contact heater shown in Fig. 1 ; and Fig. 6 is a top plan view of another embodiment of the contact heater shown in Fig. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to Fig. 1 , there is shown an apparatus for decorating an object constructed in accordance with the principles of the present invention, the apparatus being identified by reference numeral 11. As will be described further in detail below, apparatus 11 can be used to apply a label supported on a continuous carrier web onto an object O, such as a rounded container, so as to yield a labeled object O L . The label is supported on carrier web to form a heat-transfer label, heat-transfer labels being well known and commonly used in the art. Apparatus 11 comprises a turret 13 for sequentially advancing object O before decoration and for sequentially advancing labeled object O L after decoration, an indexing mechanism 15 for properly orientating object O at an indexing station 17, a label transfer system 19 for applying a label from the carrier web onto object O at a transfer station 21 so as to yield a labeled object O L , a contact heater 23 for post- treating labeled object O L at a post-treatment station 25, an infeed conveyor 27 for delivering objects O into turret 13 at an entry station 29 and an outfeed conveyor 31 for removing labeled objects O L away from turret 13 at an exit station 33. As will be discussed further in detail below, the novelty of the present invention lies in the utilization of contact heater 17 for post-treating labeled object O L as well as the positioning of post-treatment station 25 at turret 13. Turret 13 comprises a fixed plate 35 having a top surface 37 onto which object O is loaded at entry station 29. A starwheel 39 is fixedly mounted on a central shaft 41 which, in turn, is rotatably mounted on fixed plate 35. Central shaft 41 is rotatably driven by a motor (not shown) so as to rotate starwheel 39 relative fixed plate 35. As such, starwheel 39 rotatably advances object O in a counterclockwise direction, as represented by arrow A in Fig. 1 , from entry station 29, to indexing station 17 and to transfer station 21 and then advances labeled object O L from transfer station 21 to post-treatment station 25 and to exit station 33. Fixed plate 35 includes an opening 43-1 at indexing station 17, an opening 43- 2 at transfer station 21 and an opening 43-3 at post-treatment station 25. Turret 13 also comprises a cup assembly 44-1 disposed within opening 43-1 , a cup assembly 44-2 disposed within opening 43-2 and a cup assembly 44-3 disposed within opening 43-3. Cup assemblies 44 are capable of rotatable and vertical displacement and are disposed so that the top surface of each cup assembly 44 is coplanar with top surface 37 of fixed plate 35 in the absence of a downward force on cup assembly 44. In use, cup assemblies 44 serve to hold the object to be decorated in place during the associated application steps. The particular construction of cup assemblies 44 is not critical to novelty of the present invention and accordingly could be replaced by alternative holding means without departing from the spirit of the present invention. Turret 13 further comprises a nozzle 45-1 disposed above opening 43-1 , a nozzle 45-2 disposed above opening 43-2 and a nozzle 45-3 disposed above opening 43-3. Nozzles 45 are disposed to project down into the object to be decorated which, in turn, displaces cup assemblies 44 below top surface 37 of fixed plate 35. In this manner, nozzles 45 serve to hold the object to be decorated securely in place in cup assemblies 44 and to provide air into the interior of the object to provide internal support for the object. It is to be understood that apparatus 11 is not limited to the use of nozzles 45. Rather, nozzles 45 could be replaced with alternative support means, such as mandrels, without departing from the spirit of the present invention. Label transfer system 19 is located at transfer station 21 and serves to apply a single label disposed on the carrier web onto object O so as to yield a labeled object O L . Label transfer system 19 comprises a heatable platen 47 and a rubber label transfer roller 49 which is translationally-movable towards and away from the object to be decorated. It is to be understood that the particular construction of label transfer system 19 does not serve as a principal feature of the present invention and accordingly, may be represented by any label transfer system which is well known in the art. Apparatus 11 further comprises a web transport system 50 for delivering the web of labels into position between label transfer system 19 and object O. It should be noted that the particular construction of web transport system 50 does not serve as a principal feature of the present invention and accordingly, may be represented by any web transport system which is well known in the art. For example, web transport system 50 may be a label carrier web transport system with electro-optical label detection of the type disclosed in U.S. Patent No. 4,452,659 to Geurtsen et al., which is incorporated herein by reference. Indexing mechanism 15 is positioned at indexing station 17 and serves to properly orientate object O before object O is advanced to transfer station 21 for decoration. It should be noted that the particular construction of indexing mechanism 15 does not serve as a principal feature of the present invention and accordingly, indexing mechanism 15 represents by any indexing mechanism which is well known in the art. It should also be noted that the proper orientation of object O before advanced to transfer station 21 for decoration is not required in certain applications. As a result, indexing mechanism 15 and indexing station 17 could be eliminated from apparatus 11 without departing from the spirit of the present invention. Infeed conveyor 27 and outfeed conveyor 31 may be in the form of standard conveyor belts. However, it is to be understood that conveyors 27 and 31 could be in the form of alternative transport means without departing from the spirit of the present invention. As can be appreciated, the novelty of the present invention lies in the implementation and construction of contact heater 23 to selectively contact labeled object O L for post-treatment purposes as well as the positioning of post-treatment station 21 at turret 13 rather than along outfeed conveyor 31 , thereby reducing the overall size of apparatus 11. It should be noted that contact heater 23 represents any heating mechanism which is disposed to selectively contact labeled object O L for post-treatment purposes. Preferably, contact heater 23 is movable in and out of contact with labeled object O L , as represented by arrow B in Fig. 1. In Fig. 2, there is shown a first embodiment of a contact heater 23-1 for post- treating labeled object O L . Contact heater 23-1 comprises a rotatably driven, conductive roller 51 and a heating element 53 disposed within roller 51. In use, heating element 53 heats roller 51 to a temperature sufficient to post-treat labeled object O L without melting, distorting or otherwise damaging labeled object O L , which is an object of the present invention. In Fig. 3, there is shown a second embodrment of a contact heater 23-2 for post-treating labeled object O L . Contact heater 23-2 comprises a rotatably driven, conductive roller 55 which is disposed between a pair of thermal radiators 57, each thermal radiator 57 having a heating element 59 disposed therewithin. In use, heating elements 59 heat thermal radiators 57 which, in turn, heat conductive roller 55 to a temperature sufficient to post-treat labeled object O L without melting, distorting or otherwise damaging labeled object O L . In Fig. 4, there is shown a third embodiment of a contact heater 23-3 for post- treating labeled object O L . Contact heater 23-3 comprises a internally heated platen 61 and a steel transfer roller 63 disposed in close proximity to platen 61. In use, platen 61 is heated which, in turn, heats steel transfer roller 63 to a temperature sufficient to post-treat labeled object O L without melting, distorting or otherwise damaging labeled object O L . In Fig. 5, there is shown a fourth embodiment of a contact heater 23-4 for post- treating labeled object O L . Contact heater 23-4 comprises a internally heated platen 65and a plurality of steel transfer rollers 67 disposed in close proximity to platen 65. In use, platen 65 is heated which, in turn, heats steel transfer rollers 67 to a temperature sufficient to post-treat labeled object O L without melting, distorting or otherwise damaging labeled object O L . It should be noted that rollers 51 , 55, 63 and 67 may be embossed to create a texture on labeled object O L . In addition, it should be noted that rollers 51 , 55, 63 and 67 may be contoured to conform to the surface of labeled object O L . Furthermore, it should be noted that rollers 51 , 55, 63 and 67may be coated with a non-stick material (i.e., TEFLON) to prevent possible label transfer or contamination from labeled object O L . In Fig. 6, there is shown a fifth embodiment of a contact heater 23-5 for post- treating labeled object O L . Contact heater 23-5 comprises a internally heated pad 69 having an edge 71. In use, pad 69 is heated and edge 71 is drawn against labeled object O L in a squeegee-type manner to effectively post-treat labeled object O L without melting, distorting or otherwise damaging labeled object O L . To decorate an object with a heat-transfer label using apparatus 11 , one first places the object O to be decorated on infeed conveyor 27 and feeds a web carrying the labels through label transfer system 50. As an optional step, object O and the web of heat-transfer labels may be preconditioned, or heated, to a temperature in the approximate range from 200°-400° F., thereby causing the wax layer of the heat- transfer label to begin to melt. Once apparatus 11 is activated, infeed conveyor 27 advances object O into entry station 29 and onto top surface 37 of fixed plate 35, as represented by arrow C in Fig. 1. Motor driven starwheel 39 rotatably advances object O onto indexing station 17 where indexing mechanism 15 properly orientates object O for decoration. Starwheel 39 then rotatably advances properly orientated object O onto rotating cup assembly 44-2 at transfer station 21. Nozzle 45-2 protrudes down into object O, pushes cup assembly 44-2 downward below fixed plate 37 and inflates object O with air, thereby providing object O with internal and external support. The web of heat-transfer labels are passed over internally heated platen 47 and transfer roller 49 moves translationally towards object O and transfers a label from the web into contact with object O, which is being rotated by cup assembly 44-2. At the completion of label transfer, nozzle 45-2 retracts and starwheel 39 rotatably advances labeled object O L onto rotating cup assembly 44-3 at post-treatment station 25. With labeled object O L advanced onto post-treatment station 25, nozzle 45-3 protrudes down into object O, pushes cup assembly 44-3 downward below fixed plate 37 and inflates object O with air, thereby providing object O with internal and external support. Contact heater 23 then moves translationally towards and selectively contacts labeled object O L , the heat produced by contact heater 23 effectively post- treating labeled object O L . At the completion of the post-treatment process, nozzle 45-3 retracts and starwheel 39 rotatable advances labeled object O L to exit station 33 where outfeed conveyor 31 moves labeled object O L away from turret 13, as represented by arrows D in Fig. 1. The embodiments shown in the present invention are intended to be merely exemplary and those skilled in the art shall be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined in the appended claims.

Claims: WHAT IS CLAIMED IS: 1. An apparatus for applying a label onto an object, said apparatus comprising: (a) a label transfer system for applying the label onto the object at a transfer station to yield a labeled object, (b) a contact heater for post-treating the labeled object at a post- treatment station, said contact heater being disposed to selectively contact the labeled object, and (c) a turret for sequentially advancing the labeled object from the transfer station to the post-treatment station. 2. The apparatus of claim 1 wherein said contact heater comprises a conductive roller which is internally heated. 3. The apparatus of claim 1 wherein said contact heater comprises a conductive roller and a heater element disposed within said conductive roller. 4. The apparatus of claim 1 wherein said contact heater comprises an externally heated conductive roller. 5. The apparatus of claim 1 wherein said contact heater comprises a thermal radiator and a conductive roller disposed in close proximity to the thermal radiator. 6. The apparatus of claim 1 wherein said contact heater comprises a platen and a conductive roller disposed in close proximity to the platen. 7. The apparatus of claim 1 wherein said contact heater comprises a platen and a plurality of conductive rollers disposed in close proximity to the platen. 8. The apparatus of claim 1 wherein said contact heater comprises a heated pad. 9. A method for post-treating a labeled object, comprising the steps of: (a) supporting the labeled object, and (b) selectively contacting the labeled object with a contact heater. 10. The method of claim 9 wherein the step of supporting the labeled object is accomplished using a nozzle and a cup assembly. 11. The method of claim 10 wherein the nozzle injects air into the labeled object. 12. An apparatus for applying a label onto an object, said apparatus comprising: (a) a label transfer system for applying the label onto the object so as to yield a labeled object, and (b) a contact heater for post-treating the labeled object, said contact heater being disposed to selectively contact the labeled object. 13. The apparatus of claim 12 wherein said contact heater comprises a conductive roller which is internally heated. 14. The apparatus of claim 12 wherein said contact heater comprises a conductive roller and a heater element disposed within said conductive roller. 15. The apparatus of claim 12 wherein said contact heater comprises an externally heated conductive roller. 16. The apparatus of claim 12 wherein said contact heater comprises a thermal radiator and a conductive roller disposed in close proximity to the thermal radiator. 17. The apparatus of claim 12 wherein said contact heater comprises a platen and a conductive roller disposed in close proximity to the platen. 18. The apparatus of claim 12 wherein said contact heater comprises a platen and a plurality of conductive rollers disposed in close proximity to the platen. 19. The apparatus of claim 12 wherein said contact heater comprises a heated pad. 20. The apparatus of claim 12 and further including means for supporting said labeled object during post-treating. 21. The apparatus of claim 20 and wherein said means for supporting said labeled object includes a nozzle for introducing air into the interior of the labeled object. 22. The apparatus of claim 20 and wherein said means for supporting said labeled object includes a mandrel.

Inventors: GEURTSEN FRIEDRICH H H, GEURTSEN, FRIEDRICH, H., H.
Applicants: AVERY DENNISON CORP, GEURTSEN FRIEDRICH H H, AVERY DENNISON CORPORATION, GEURTSEN, FRIEDRICH, H., H.
Application year: 1999
Main classification: B65C9
IPC codes: B65C9