GB2142900A - Method of applying plastic labels on glass containers - Google Patents

Abstract

Assembling thermoplastic sleeve coverings on rigid glass containers or bottles c and heat- shrinking the plastic covering on the container. The plastic is fed from a web 26 of material to a mandrel-carrying turret apparatus where it is cut into lengths and wrapped and seamed on successive mandrels 24, thereby forming sleeves. The bottles from a conveyor 10 are positioned over and in axial alignment with the sleeve-forming mandrels 24 and move synchronously therewith and the sleeves are telescopically assembled onto the glass bottles. The bottles are then rotated about their axes and moved through a semicircular heated zone 37 to shrink the sleeves into snug engagement with the surface of the glass bottle. After assembly and shrinking is complete, the bottles are released to an outfeed conveyor 24 completing the process. <IMAGE>

Description

SPECIFICATION Method of applying plastic labels on glass containers BACKGROUND OF THE INVENTION For several years, it has been the practice to form sleeves of thermoplastic material on a series of rotatable mandrels, for example, as shown in the U.S. Patent 3,802,942 issued April 9, 1974. This patent discloses the process of forming sleeves from the point where a foamed material is extruded as a tube, then slit into a flat sheet. The sheet has an orientation in the direction of its width due to the fact that the extruded tube has been inflated during the process of its formation to provide the built-in shrinkage characteristics which are desired, so that when the material is formed into a cylinder and applied to a container, the material will have a heat-shrink characteristic to cause it to shrink into contact with the underlying surfaces of the glass container.

Particular reference to this patent 3,802,942 may be had, and the disclosure of this patent is incorporated herein by reference.

Figs. 1 and 2 of this patent show a supply of thermoplastic material 1 5a being fed to a sleeve-making mandrel system, the mandrels being carried on a turret underlying the path of travel of the containers about an end section 68. This patent further discloses an endless chain, or pair of chains, carrying a series of neck-grasping chucks for holding the necks of the containers through the cycle of operation of preheating the containers, applying a shrinkable sleeve to the container and subsequently heat-shrinking the sleeve that has been applied to the container. It will be noted, however, that in this patent the shrinking of the sleeve takes place in a long, straight-line moving away from the turret where the sleeves have been applied to the container.

It is an object of this invention to provide a method ofihandling the containers where the containers are positioned to receive a preformed sleeve thereon, are rotated and the sleeve is shrunk thereon while the container is moving about an arc of a circle above the mandrels upon which the sleeves are being made.

It is another object to provide a much more compact sleeve-applying system than heretofore; and a method of handling the bottles and shrinking the sleeves thereon is carried out in a less extensive operation than that of the above-cited patent.

Further objects will be apparent from the following description.

SUMMARY OF THE INVENTION In the present invention, a succession of cylindrical sleeves are formed on mandrels from lengths cut from a rolled supply of shrinkable predecorated plastic web material.

The bottles are carried by chucks in vertical alignment with the mandrels and the sleeves are assembled onto the bottles. The assembled bottles and sleeves are then heat-shrunk within the rotary movement of the mandrel itself by rotating them about their axes while moving them through an area between two opposed heating devices that extend about a portion of the circumference of the handling system. The length of the heaters is sufficient to complete shrinkage of the plastic sleeve about the container. The finished articles are then carried away from the handling turret.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic, perspective view of an apparatus for carrying out the method of the invention; and, Figure 2 is a top plan view of the apparatus of Fig. 1 taken from the level of the mandrels.

DETAILED DESCRIPTION OF THE DRAW INGS From the disclosure of the above-cited patent, it can be seen that the making of sleeves from thermoplastic, foamed material supplied in ribbon form is old in the art. It can also be seen from the above-referred-to patent that the moving of the formed sleeves from a series of mandrels onto containers that are positioned thereabove is also known from the prior art. It should also be noted that in the prior art the bottles which are to be provided with a sleeve label, shrunk in place thereon, are preheated in a preheat oven prior to being received in the sleeve-applying machine. An alternative embodiment, identified in the patent as the on-line embodiment of Fig. 2, receives its supply of hot bottles from the annealing lear of a typical glass bottle forming machine.The preheated bottles are then conveyed to the sleeve-applying machine where they are grasped by their necks and conveyed in series into and through the sleeve-applying portion of the machine and afterwards transported, still by their necks, through a heatshrink tunnel for shrinking the applied sleeve onto the sides and bottom of the container.

The method and the apparatus disclosed in the above-referred-to U.S. Patent 3,802,942 is intended to provide sleeved containers at rates up to 500 bottles per minute. In contrast to the operation of the machine of this patent and the method which it employs, the present invention will receive their glass containers in upright position on a moving belt conveyor generally designated 10. The incoming containers C on the conveyor 10 will be engaged by a side-engaging starwheel 12 that is formed with a plurality of pockets in its periphery, it being understood that these pockets will engage the sides of the containers as they are moved on the conveyor 10 and will move the containers, one at a time, into the position designated 13 on Figs. 1 and 2.At this position the container, which is entering the sleeve-applying portion of the machine, will be engaged by and gripped at its neck by a set of tongs 14. The tongs 14 are shown in detail in Figs. 5 and 6 of U.S.

Patent 3,802,942. The tongs 14 are mounted at the lower end of a chuck mechanism, generally designated 15. The chuck mechanism 15 is mounted onto two rotating discs 16 and 17. The discs 16 and 17 are mounted coaxially on a vertical axle 18. The axle 18 in turn is connected to a gear 19. The gear 19 is driven by a spur gear 20 extending from a transmission 21. The transmission 21 is driven by a vertical shaft 21a connected by suitable gearing to an electric motor 22. The motor 22, as shown in Fig. 1, also drives a lower bull gear 23. The bull gear 23 also rotates about the central axis of the machine which is coincidental with the axle 18. This bull gear supports a turret (not shown) that provides the transporting mechansim for a plurality of sleeve-forming mandrels 24.The mandrels 24 are individually rotatable about their vertical axes by a mechanism not here shown, but shown in detail in the referenced patent 3,802,942.

As can be seen when viewing Fig. 2, the mechanism has eighteen mandrels in a circular array about the axis of the axle 18. The mandrels 24 sequentially receive foam sleeveforming material in discreet length from a transfer drum 25. The sleeve-forming material comes in the form of a continuous endless strip 26, moving in the direction of the arrow shown thereon in Fig. 1. The strip is fed between a pair of roll stands 27 into engagement with the periphery of the drum 25. The drum 25 is provided with vacuum ports therein to engage and grip and carry the strip 26 therealong. While the strip of material is engaged by the drum, it will be cut by a rotary cutter 28 operated in timed sequence with the feeding of the strip material 26.

Thus, there will be provided on the surface of the drum 25 a discreet length of the strip material 26. This strip of material is then transferred from the drum 25 to a mandrel 24 that is brought into tangential relationship to the drum 25. This mandrel, to which the discreet strip is to be transferred, is an empty or bare mandrel at the time that it arrives opposite the drum 25. The mandrel also has a row of vacuum ports spaced vertically along the wall thereof, which will take the leading edge of the strip material from the drum 25.

The mandrel at this time is rotating in a counterclockwise direction as viewed in the drawings. The mandrel will then rotate an amount sufficiently to complete the rolling or wrapping of the strip about the mandrel into a cylindrical sleeve surrounding the mandrel.

The complete wrapping occurs at approximately the 65 point on the layout in Fig. 2.

At about 67' of the rotation of the mandrels, a cam 29 will move a cam follower 30 radially outward to push a heat-sealing bar 31 into the overlapped portion of the sleeve surrounding the mandrel 24. It should be understood and, as explained in detail in patent 3,802,942, that the mandrel winding and the position of the vacuum holes in the mandrel are such that the trailing edge of the strip of material will be overlying the leading edge at the point in the cycle of operation where the heat-sealing bar 31 is moved into engagement with the overlapped portion. At this time, the mandrels are disengaged from any individual rotational drive and the heating or sealing bar will remain in sealing contact with the overlapped portion until the seam welding is completed at the 217 point in the overall rotation of the mandrel-carrying turret.Shortly after this, in the cycle of the turret movement the incoming bottle from the conveyor 10 will be picked up by a chuck 15 and the chuck 15 will position and hold the bottle in coaxial alignment with an underlying mandrel containing a completed sleeve. While only a single chuck 15 is shown in Fig. 1, it should be kept in mind that there is a chuck for each of the mandrels, therefore there are eighteen chucks which are coaxially positioned above the mandrels 24.

The jaws of the chuck 14 are opened and closed by the manipulation of a cam follower 35 carried thereby. The cam follower 35, throughout most of the cycle of operation of the machine shown in Fig. 1, is not operated.

However, manipulation of the cam follower 35 by a cam 34 will open the tongs and effect the release of a completed bottle and then pick up a bare container in order to carry it through the cycle.

Vertical movement of the chuck 15 is not necessary for the releasing of a bottle which has received a sleeve and the picking up of a bare bottle to begin the sleeving cycle. However, steadying of the chuck 15 during this phase of the operation may be carried out by a cam 33 engaging a roller 32 at the upper end of the chucks 15. As shown in Fig. 1, the cam 33 is a box cam within which the roller 32 will pass, while the cam 34 is a generally flat bar that will dip down at the release point for the bottles and remain down until a bottle is ready to be grasped at the point 13, where cam 34 will release the follower 35 resulting in the grasping of the bottle neck. At this time, the cam 33 may release the follower 32 and let the chuck remain in the proper position.

As previously stated, the bottle at position 13 is held by its neck by a chuck 15 and, as it moves in synchronism and in vertical alignment with an underlying mandrel, a stripper mechanism will strip the formed sleeve from the underlying mandrel and telescope it vertically upward around the circumference of the container. This movement is illustrated by the arrow 36.

As shown in Fig. 2, the stripper starts up at the 260 mark and completes its action by the 300 mark, just in advance of entry of the container into a sleeve-shrinking heater. The heat-shrinking mechanism comprises a pair of semi-circular heaters 37 -and 38. The heaters 37 and 38 are spaced apart sufficiently to permit passage of a container with applied sleeve therebetween and, in effect, as a unit constitutes a heat-shrinking oven. During the movement of the containers carried by the chucks 15 through the gap between the two heaters 37 and 38, the tong portion of the chucks are rotated about the vertical axis of the chucks. This rotation is accomplished by an annular surface 39 of the chuck engaging a stationary cam plate or bar 40.The bar 40 may be faced with a friction material in the - manner taught in U.S. Patent 3,802,942 and shown at 250a of Fig. 6 of this patent.

Thus, it can be seen that rotation of the chucks and the containers carried thereby during their transport through the gap provided between the heaters 37 and 38 will provide even heating of the sleeve material so that it will be shrunk in a uniform manner about the circumference and sidewalls of the containers. The chucks continue in their counterclockwise movement about the axle 18, and at a point or position 180 removed from the 0 position, will release the containers with their sleeves applied so that a sideengaging starwheel 41 will move the com pleted and assembled containers from the assembly and shrinking machine onto an outfeed conveyor 42.

The heaters 37 and 38, which in a sense constitute a significant portion of the invention, may be formed of sheet metal with a plurality of radiant, cairo type heating ele ments extending along the length thereof in facing relationship with respect to the container and the sleeve carried thereby. Alternatively, the heaters may be of any selected type, such as blown hot air which directs air against the sleeved container.

Having described a schematic representation of the apparatus that could be used in the method of the invention, the process which is performed by the apparatus will be described in the sequence of its operation to receive bare bottles and a strip of plastic wrap material and produce a container having a heatshrunk sleeve applied thereto.

In the prior art, as exemplified by the above-referred-to U.S. Patent 3,802,942, the containers to which shrunken sleeves are to be applied were moved along through a preheater oven to heat the bottles, or were provided from the forming machine or the annealing lehr at a somewhat elevated temperature. The bottles were picked up by individual sets of tongs and chucks and moved along a straight path. The chucks travel on an endless driven carriage to transport the bottles through a preheated and past the sleeveforming turret where the fabricated sleeves are assembled telescopically onto the containers. Then the chucks will carry the containers into and through an elongated, linear tunnel oven wherein the sleeves shrink to conform to the article shape. With shrinkage complete, they are transported to an unloading station.

Timed with the bottle-handling apparatus is the sleeve-making apparatus which receives a thermoplastic web material from a supply.

This is guided in oriented fashion onto a feed drum where lengths are cut and transferred to mandrels. The lengths are each wound onto the cylinder-like mandrels and seamed at an end-to-end overlap region to form a complete cylindrical sleeve. The mandrels move in time with the bottles about the common axis of the mandrel-supporting turret. The sleeves, after being heat-sealed, are stripped from the mandrels and placed over the body of the bottles.

It should be noted in this patent that the bottles which are picked up are carried for a considerable distance before they reach the assembly area, and after the sleeves are assembled thereto, they move again through a relatively long heat-shrinking tunnel and the completed bottles are released onto an exit conveyor. With this system, a relatively large area of a manufacturing plant must be set aside and devoted exclusively to the elongated handling mechanism and heating systems disclosed.

In contrast to the foregoing description of the prior art, the present invention provides a compact handling system in which the sleeves are made on a turret machine in essentially the identical form as that disclosed in the above-referred-to patent. However, the bottles are picked up by chucks which move in alignment with the mandrels without having them carry the bottles away from the mandrelsupporting turret. The process of the invention is such that newly formed containers C, or containers brought from storage, are placed on an incoming conveyor where they are met by an indexing pocketed starwheel which moves about a vertical axis to index the containers, one at a time, into alignment with the mandrels as they are moving past the end of the incoming conveyor.At this time, the chuck will be opened so that its tongs may grasp the neck of the container, yet maintaining the bottle in coaxial alignment with the underlying mandrel. From this point forward, the specific chuck, bottle and mandrel stay in coaxial alignment. The mandrel at this point will have a sealed sleeve surrounding it and the sleeve will be moved upwardly around the bottle positioned thereabove. The sleeve is actually pushed upward by a stripper during the interval of 260 and 300 , as indicated in Fig. 2, when the stripper will be beginning to retract from its uppermost position.At 310 , the bottle-holding chuck will be rotated about its vertical axis and the bottle and sleeve carried thereby moves through the area between two heaters to effect the shrinking of the foamed plastic sleeve about the container while it is moving within the circumference of the mandrel turret. The shrinking will continue until the bottle has been moved through ap proximately 1 15 of the circumference of the mandrel-supporting and chuck-supporting turret. Continued movement of the bottles by the chucks will take place; however, rotation is stopped once the container and sleeve has cleared the end of the heaters.At approximately 180 , indicated in Fig. 2, the chuck will release the container with the sleeve attached and the container will be engaged by a starwheel 41 which will move the container in an arcuate path onto the outfeed conveyor 42.

The significant thing which is being carried out by the invention is the fact that the shrinking of the sleeve is accomplished within the movement of the bottle in the turret itself without having an external large heating system. This is partly because of the fact that the system runs at a somewhat slower speed than that which is described in the above-referredto patent 3,802,942. Also, the weight of the bottles is becoming less and, for that reason, it is not as critical that the bottles be heated to such a degree prior to the shrinking of the sleeve thereon. The sleeves, as previously explained, are made from a web of material fed to the mandrels from a transfer drum and in essence the process of forming the sleeves and transferring the sleeves is generally the same as that described in the above-referredto patent.

In view of the foregoing, it can be seen that a process is provided which will handle glass containers and apply sleeves of thermoplastic, shrinkable material thereto which involves the use of less expensive equipment in construction and in space-saving in that it is relatively small compared to the commercial predecessor. While the present invention has been described with regard to a specific piece of equipment for forming the product of the process, it should be kept in mind that some of the steps could be performed by other apparatus, although that which has been described is the apparatus for performing the preferred process of the invention.

While the foregoing description talked in terms of the sleeve being a foam material, such as that disclosed and described in U.S.

Patent 3,802,942, it should be kept in mind that there are other shrinkable thermoplastic materials which may be provided with a shrink memory that would be suitable in the present invention, and it is not intended to limit the scope of the appended claims by reason of the recitation of a specific shrinkable thermoplastic material being utilized in the process.

Claims (4)

1. In the method of applying a label to a glass container, wherein labels of heat-shrinkable foamed plastic are fed from a roll supply to a drum where they are severed into individual labels, then individually transferred to one of a series of winding mandrels carried on a rotating turret with the labels being heatsealed into complete, cylindrical sleeves on the mandrels, with an individual container supported above and in axial alignment with each of the mandrels, the containers and mandrels being moved together in synchronism, with the formed sleeves being telescoped from the mandrel onto the container thereabove, the improvement therein comprising the step of rotating the container and sleeve about its vertical axis while moving about the axis of the turret and heat-shrinking the sleeve about the container while the container is moving and then releasing the container with label thereon to an exit starwheel for moving the container onto a moving belt conveyor.

2. The method of Claim 1, further comprising the step of rotating the container about its vertical axis while applying heat to the label assembled thereon to provide even shrinkage of the sleeve label onto the container.

3. The method of Claim 1, further including the step of applying heat to the container and assembled sleeve with infra-red radiation extending along both sides of the path of travel of the container for a time sufficient to completely shrink the sleeve into conforming relationship to the container.

4. A method of applying a label to a glass container, substantially as described with reference to the drawings.