NZ217648A

NZ217648A - Apparatus for applying heat activatable adhesive labels to containers

Info

Publication number: NZ217648A
Application number: NZ217648A
Authority: NZ
Inventors: F J Difrank; T W Moore
Original assignee: Owens Illinois Inc
Priority date: 1985-11-04
Filing date: 1986-09-22
Publication date: 1988-03-30
Also published as: KR870004884A; JPS62109734A; CN86106943A; ZA868072B; FR2589431A1; GB8626107D0; JPH0360728B2; AU6313786A; ES2003459A6; IT1199278B; MX160897A; BR8605411A; IT8648579A0; AU569432B2; DE3637465A1

Description

<div class="application article clearfix" id="description"> C1TG-I8 Priority Date(s): . Complete Specification Frted: Class: 61c.TM/.ta 30HARf988 Publication Date: P.O. Journal. No: J. 3Pf? NEW ZEALAND PATENTS ACT. 1953 No.: Date: COMPLETE SPEC1FICATION METHOD AND APPARATUS FOR APPLYING A PLASTICS LABEL ABOUT A CONTAINER jiWe, OWENS-ILLINOIS INC. a Corporation organized under the laws of the State of Ohio of One Seagate, Toledo, Ohio, U.S.A. hereby declare the invention for which I / we pray that a patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - - 1 - Background of the Invention The present invention relates to apparatus fund method for applying wrap-around thin plastics labels to containers with the containers moving in an upright attitude in a continuous motion through the labeling operation. It has been known to apply labels around containers by moving the containers at spaced intervals into tangential engagement with a drum that carries individual labels held to the surface of the drum by vacuum. As the drum carrying the labels rotates about its axis, glue, or more recently a solvent for the plastics material of the label, is applied to selected areas of the label and the label will adhere and transfer from the drum to the container. The container continues to roll along the drum periphery and consequently the label is wrapped around the circumference of the container. The label is somewhat longer than the container circumference and thus the trailing edge of the label will overlap the leading edge or the portion of the label which was first adhered to the container. This trailing edge will be sealed to and overlap the leading edge to form a complete, encircling label on the container with a complete vertical seam. This system was well suited to labels which were not heat sensitive. In those instances when the label material was made of less heat sensitive plastics or paper laminates, a hot-melt adhesive could be used. Since most commercial hot-melt adhesives have a melting point greater than 300°F, it is unsuitable for use as an adhesive when the label is formed of thin, heat sensitive plastics. The hot-melts will cause distortion in the label or actually destroy the integrity m 217648 It ia important that the labeling system be fairly free of hangups and that the speed of movement of the containers through the system be uniform and rapid. When glues that require too long a time to set up are used, obviously, the system must be operated at a relatively slow speed. This is what has led to the use of hot-melt adhesives which have the fast setting properties when the label is compatible. One other drawback to the use of hot-melt glues is the expense of heating the glue and the sometimes messy operation when the glue is applied to the label. In view of this lack of compatibility with thin plastics labels of hot-melt glue, the use of a solvent has been considered. A solvent system is disclosed in co-pending New Zealand patent Specification No. 209675 dated 9 April 1987, and the system is described for applying a completely encircling label of thin plastics material about a container such as a plastics bottle. The solvent system is preferred in those situations where the label is a fairly thin plastics sheet or thin film foam laoninate and is to be adhered to an oriented plastics container. It is helpful to have the label applied to an oriented plastics container in a manner such that it can be stripped from the container upon recyling of the container. Removal of the label is facilitated if the label is adhered to the container with a small spot of solvent applied to the leading edge of the label and then a full line of solvent applied to the overlapping or trailing edge. The label tightly adheres to itself but lightly sticks to the container. Thus, stripping can be accomplished with little effort and expense. It is an object of the invention to provide a method or apparatus for applying wrap-around labels to containers. .-provides a system for applying relatively thin plastics labels to containers, . T * -i With the foregoing in view, a preferred form of the present invention <:C 1987 -such as glass containers by using labels that have a heat activated glue thereon. The labels are somewhat longer than the bottle circumference and the labels are transported on the exterior surface of a vacuum drum into tangential relationship to the bottle or container. Heat is applied to the adhesive at a point just in advance of the arrival of the label to the point of tangency with the container where the label is tacked to the container surface and effectively released from the drum surface. A heat activated adhesive whose polymers crosslink is also carried at the trailing edge of the label and will be adhered to the leading edge by becoming overlying with respect thereto. The heat activated glue is such that it will quickly set and make an extremely tight overlapped seam so that subsequent heating of the sleevelike label will cause the sleeve to shrink into closely conforming relationship to the container and will not disturb the integrity of the label. Since the polymer of the adhesive will become cross-linked by the heat, the label will form a seam that will resist the tension applied during heat shrinkage. A further preferred form of this invention uses plastics labels that are precoated with an adhesive for the labeling of beer containers prior to being filled, where the cross-linked adhesive will be able to withstand pasteurization temperatures. 217648 15^7 USA 1 Brief Description of the Drawings s PZG. 1 is a top plan view of a first embodiment of the • invention; 4 FIG. 2 is a perspective view, on an enlarged scale, of s the area of label application to a container of Fig. 1; « FIG. 3 is a plan view of a second embodiment of the 7 invention; * FIG. 4 is an enlarged, perspective view taken in the ' direction of arrow 4 on Fig. 1; and 10 FIG. 5 is a perspective view of the air manifold of 1* Fig. 2 as viewed from the front thereof. ** Detailed Description of the Drawings n With particular reference to Fig. 1, which is a partial 14 plan view of the label applying portion of the invention where is a label supporting drum 10 is supported for rotation about a i* vertical axis 11 by an arm 12 which supports a central hub it 13 for the drum. The hub 13 is provided with an interior n vacuum manifold (not shown) to which a vacuum line 14 is 19 connected. It should be understood that the hub 13 does not rotate and the arm 12 is connected to a fixed support 15. A complete, detailed description of the drum 10 is not believed 22 necessary since it is of a fairly common type in which vacuum 2> passages extend radially outward from the manifold in the hub 2* to openings in the face of the drum where the leading edge of 25 an individual label 41 will be fed, in order, to be held to 2« the surface of the drum. Additional, vertical series of 2? vacuum ports will be provided to underlie the trailing edge 2S of the label to assure that as the container is rolled along 29 the drum surface as the drum rotates, that the label will roll #0 evenly around the container. In the instant application and si M ^ 1 / •! ft •J as shown in Fig. 1, the labels may be supplied from a roll (not shown) and be fed in. ail endless web 16 of labels which have adhesive areas pre-printed thereon. As the web 16, as viewed in Fig. 1, enters the view from the right, it will be engaged by a pair of nip rollers 17 and 18 and after passing around nearly one-half the circumference of roll 18 it will engage a feed roll 19 which will feed the web into the zone of a web slicer 20 which will cut the web at a precise point in its length to define a length of the web that will be a label. The leading edge of the label, before being severed from the . web, will be guided into engagement with the periphery of the drum 10 by a guide 21. When the web engages the drum, the vacuum ports in the drum will hold the web against the drum and rotation of the drum draws the web through the knives 22 and 23 of the rotary slicer 20. The blade 22 is in a reciprocating holder while the blade 23 is carried by a rotating holder so that at the precise, predetermined time, both of the blades engage the web and effect the severing of the web into the precise label length. It should be pointed out that the leading edge of the web, as seen in Fig. 4, has an adhesive thereon in at least two vertical ly spaced areas of adhesive 45 on the outside surface, facing away from the drum. In a like manner, adjacent the trailing edge of the label, the label has a full height or transverse line of adhesive 4 5 die printed thereon. The adhesive that is used is characterized as a water born, printable adhesive with heat seal capabilities. An example of a particular adhesive is a cross-linking thermosetting adhesive such as carboxylated ethylene vinyl acetate. This adhesive is heat activated at approximately 210°F and will become cross-linked and when cured will \ l2°CTl98y^ 217648 15&77 USA l softening point in excess of 300*F. The cure time for the S adhesive is less than one minute and when cured will be capable • of resisting the pasteurization temperatures that containers of 4 beer are subjected to after filling. Since the heat activation • temperature is only 210*F, the labels will not be subject to • the distortion temperatures which would normally accompany 7 the application of the conventional hot-melt adhesives which • require at least a 350°F temperature to be made molten, it • being understood that up to now only labels applied with a 10 hot melt adhesive have been able to withstand pasteurization ■ 11 temperatures. is As seen in Fig. 1, a label 41, which is carried by the it drum 10 on its rubber layer or facing 10a, has engaged a 14 container C and, just prior to its being picked up by the is container, the adhesive 45 on the label's leading edge is is activated by passing in front of a hot air source, generally if designated 24. The source 24 is in the form of a generally u hollow rectangular box 2 5 formed with an opening 26 in a side 27 ll thereof that faces the drum 10. A conduit 28 is in communi-*o cation with the interior of the box 25 and is connected to a si source of hot air (not shown). Thus, it can be seen that as 22 the label is transported by the drum, the area of the adhesive 23 will come into registry with the opening 26 in the box or 24 manifold 25 and hot air will impinge on the adhesive. The 26 size of the opening 26 is selected, considering the rate of 26 movement of the drum and the temperature of the hot air so that 27 a sufficient activation of the adhesive will occur as it 21 passes the opening 26. Immediately after being exposed to the 21 activation temperature of 210°F, the adhesive on the label will so be engaged by the side of an incoming container C and the si 15 217648 15877 USA l container will roll along the drum surface while held there-s against by a curved guide 29, with the label becoming rolled I thereon. The trailing edge of the label, where a full height « line of adhesive is carried, will be likewise activated by the I application of hot air from the chamber 25 and the trailing 6 edge will overlap the leading edge at this time. Since the 7 container is confined between the drum surface and the container • guide bar 29, the overlap area will become a vertical seam that • extends the full height of the label. The container and 10 seamed label will then be guided by a curved exit bar 42 onto 11 a conveyor 30, moving to the right as viewed in Pig. 1, through 15 a heat shrink area 31, between a pair of infrared heaters 32. it As can readily be seen from Figs. 1 and 2, the containers 14 enter the labeling area from the left and are normally moved 16 to the right while resting on a moving conveyor until they are i« engaged by a pocket 33 of a rotating starwheel 34 which is J7 rotated in the direction of the arrow thereon. The container il is guided in its movement into the position for engaging a 19 label by the bar 29 on one side of its path of movement and a >o pair of vertically spaced guide rails 35 on the opposite side. Si The guide rails 35 are formed so that they will guide the containers in a curved path which has its center of curvature the same as the starwheel axis so the containers will 2« asymtotically engage the adhesive area of the leading edge of 26 a label. The guide bar 29 in its initial length is generally 26 parallel to the guide rails 35. However, once the container 27 has engaged the label, the bar 29 will change its curvature so 2i that the container will follow a path that is parallel to the 29 drum circumference. Thus, the guide bar 29 will describe a so curve which is coaxial with the axis of rotation of the drum 10. si is -7- Of course, the starwheel will push the container along the periphery of the drum and when the container leaves the star-wheel, it will still roll along the drum surface because of its being held in engagement with the drum by the bar 29. With reference to Fig. 3, em alternative form of the invention can be seen with like elements being given the same reference numbers as those of Fig. 1. In this embodiment, a preheat oven 36 is positioned over a conveyor 37 on which the containers are positioned and are moved in series toward the starwheel 34. A reciprocating gate 38 is positioned to engage and effectively hold back the containers and let them move one at a time into the starwheel as the pockets move over the conveyor. In this embodiment, the containers are preheated to a temperature that is in excess of 210eF generally about 250°r and the heat of the container will activate the adhesive carried by the label and initiate the cross-linking. The container will have sufficient heat so that the trailing edge of the label where adhesive is present at the full label height will also be heat activated, resulting in a full vertical seam being formed at the overlap. In addition to the elimination of the "hot air" adhesive activation system by having preheated bottles whose heat content will activate the adhesive, the labels 46 are ones that are precut, with adhesive already applied, and stored in a magazine 4 8 where they can be fed serially to the periphery of the vacuum drum 10 by a pair of feed rolls 39 and 40 driven in synchronism with the drum drive and starwheel drive (not shown). While the foregoing description provides two systems for feeding labels that are pre-printed with adhesive to a vacuum drum for transport to a position where the container ' -8- 217<>48 engage the adhesive area of the label to first stick the leading edge of a label to the container and then roll the container over the label and drum to wrap the label about the container, it should be apparent that the heat activated adhesive on the label can be heat activated by means other than the preheated bottle or the hot air system. For example, the adhesive could be activated by exposure to infrared heaters just in advance of the engagement of the label with the bottle or a combination of a preheated bottle preheated to between 150°F and 200°F and auxiliary heat applied to the glue or adhesive areas on the label will effectively provide a wrap-around label. The label is a thin plastics material which would be distorted if too much heat is applied as in the case of "hot melt" adhesives. The adhesive must be quick curing so that the labeled container can pass through a heat shrink oven to shrink the label about the container and the labeled container must be one which can withstand pasteurization temperatures that are required for filled beer bottles. Having described the best mode contemplated for carrying out the invention, other modifications may be resorted to within the scope of the annexed claims. 9- </div>

Claims

<div class="application article clearfix printTableText" id="claims"> ^ J' b 4 6 WHAT WE CLAIM IS:

1. A method of applying an encircling label to a container wherein a label having a leading edge and a trailing edge adapted to be overlapped is provided with an adhesive on the — leading and trailing edges and is transported on the periphery of a transport drum to a position where the container is brought into contact with the adhesive on the label, the label and container are then rolled along the periphery of the drum to effectively wind the label about the container until the label's trailing edge overlaps the leading edge so as to make a sealed seam, ——— wherein at least two areas of an adhesive are preapplied to the labels before they are adhered to the transport drum, said adhesive being a heat activated cross-linkable polymer and including the step of applying heat to the adhesive on the leading edge at the time the label is first engaged by a container and applying heat to the adhesive on the trailing edge just prior to the overlapping of the trailing edge over the leading edge.

2. The method of Claim 1 wherein the application of the activation heat to the adhesive is by applying hot air to the adhesive.

3. The method of Claim 1 wherein the application of the activation heat to the adhesive is while the label is carried by the drum just in advance of the transfer of the label to the container. -10- 3 4 1 2 3 4 5 1 2 1 2 3 4 5 1 2 3 4 1 2 217648 15877 USA

4. The method of Claim 1 wherein the activation heat for the adhesive is applied to the label adhesive while the label is carried by the drum just prior to the label contacting the container.

5. The method of Claim 1 wherein the activation heat for the adhesive is provided by preheating the container to a temperature above the activation temperature for the adhesive but below the temperature at which the label will be heat distorted.

6. The method of Claim 5 wherein the container is a glass container preheated to a temperature of about 2504F.

7. The method of Claim 1 wherein the activation heat for the adhesive is provided by the steps of preheating the containers to a temperature of between 150°F and 20 0°F and impinging a stream of hot air on the adhesive just prior to engagement of the container with the label.

8. The method of Claim 7 wherein the combined preheating of the containers and the impingement of hot air on the adhesive will provide an activation and cross-linking of the polymer.

9. The method of Claim 8 wherein the combined heating of the polymer will be to a temperature of about 210#F. -11- 217648

10. An apparatus for applying thin plastics labels to the cylindrical aides of containers wherein the labels are carried by a vacuum transport drum to a pickup point where the containers are brought into tangential engagement with a heat activatable adhesive carried on the label, and the container is rolled along the drum surface to wind the label around the container and form an overlapping seam, comprising, means adjacent the drum surface for applying heat to the adhesive on the label as it approaches the pickup point to thereby activate the adhesive before it • is applied to the container.

11. The apparatus of Claim 10 further comprising a preheat oven and means for passing the containers through the preheat oven on their way to the pickup point.

12. The apparatus of Claim 10 wherein the means for applying heat to the label adhesive comprises a manifold chamber adjacent the surface of the transport drum, an opening formed in said chamber in confronting relationship to the periphery of said drum and means for supplying hot air to the interior of said chamber.

13. The apparatus of Claim 10 wherein said means for applying heat to the label adhesive comprises a radiant heater facing the drum surface to activate the adhesive.

14. The apparatus of Claim 13 wherein said radiant heater is an infrared heater. 2l7U4d

15. Apparatus for applying thin, plastics labels to glass containers wherein the labels have preapplied heat act!vatable, adhesive thereon at a leading and trailing edge thereof and the labels are transported in series by a rotating vacuum drum to a pickup point where the containers are brought in series into engagement with the leading edge of a label, comprising a preheat oven, means for passing the containers through the preheat oven on their way to the pickup point whereby the activation of the adhesive is the result of the hot container engaging the adhesive as the container is rolled along the surface of the vacuum drum to provide a container with a complete circumferential label with a vertical overlap seam.

16. A method of applying an encircling label to a container substantially as hereinbefore described with reference to the accompanying drawings.

17. An apparatus for applying thin plastics labels to the cylindrical sides of containers substantially as hereinbefore described with reference to the accompanying drawings » ^ oiOt'rt.o • J,ic. By r authorised Agents., A. j. PARK. & SON. per / if*;..as;\;,0 s-* - 1 FEB 1988 </div>