Technical Field

The present invention relates to a method of labeling containers with labels which are prepared to facilitate being stripped from the containers.

Background Art

Containers for products are labeled by various methods . One example of a container produced in high volumes which has constantly been improved in its method of labeling is a soft drink container. These containers were originally formed of glass directly decorated with painting or printing. Soft drink cans were subsequently developed wherein labels were directly printed on the surface of the cans by lithography. Due to environmen¬ tal and cost considerations, directly decorating con¬ tainers such as glass bottles and cans has been sup¬ planted by applying pre-printed labels to these contain¬ ers. These labels can be produced and applied at low cost to containers as part of a container filling line. Originally, these labels consisted of paper and were applied to the containers with glue. The paper labels were subject to degradation from moisture and other environmental factors.

The bottling industry improved paper labels by applying a thin layer of plastic over the paper for protection. Other labels developed include polystyrene foam labels and, more recently, film labels. Selection of labeling materials for various containers is influ- enced by factors such as cost, convenience of applica-

tion and use, and ability to reuse and recycle the containers .

One problem in recycling or reusing containers relates to the de-labeling or the removal of labels. For example, paper labels which are pasted or glued on containers are frequently removed by immersing the labeled container into a washer of hot caustic solution. An example of a machine used to apply caustic solution to a labelled container is disclosed in U.S. Patent No. 4,044,783 issued to Babunovic, et al . However, caustic solution baths do not work well with plastic labels because plastic is impervious to moisture. Furthermore, the washer may become subject to label congestion as a large number of containers are fed through the washer in a relatively short time.

Tough, axially oriented film labels are also difficult to remove from containers. If a durable film label is applied to a glass or plastic bottle, it can be difficult to remove the label without harming the surface of the container. In particular, when an oriented film is applied to a polyethylene tetraphthal- ate (PET) bottle, the known processes for de-labeling containers can scratch or cut the underlying container. It has been proposed that PET containers could be reused without remelting if they could be de-labeled and adequately sanitized without injury to the bottle.

Known de-labeling methods include mechanical de-labelers wherein fingers are used to scratch and tear the label from the container as it moves down a de- labeling line. For instance, U.S. Patent No. 4,122,734 issued to Hurst, discloses a label stripping machine utilizing a razor for cutting off the label from the

contamer Another approach to cutting the label is to use air or water net knives. As disclosed m U.S. Patent No. 4,717,442 issued to Hopson, air ets are directed between the label and the container m order to rupture the label .

A difficulty with either mechanical stripping fingers, razors, or jet knife de-labelers, is control¬ ling the depth of the cut and the force used to remove the label m order to avoid scratching or cutting the container. If a PET container is scratched or cut, it is unusable and must be remelted before being recycled. Likewise, if a glass container is cut or scratched m the course of de-labeling, the container can be ruined, requiring it to be remelted and reformed into a new bottle

A pressure sensitive, price tag is shown m U.S. Patent No. 4,787,158 issued to Vitol . The dis¬ closed label has a score line which is provided for the purpose of splitmg the label if a consumer tries to remove the price tag.

The prior art has not addressed the need for a bottle labeling method which facilitates automatic de- labelmg without harming the containers as proposed by applicant below.

Summary Of The Invention

It is an object of the present invention to provide a method of labeling containers with a label that lends itself to being removed from the containers by automatic de-labeling equipment

It is another object of the present invention to provide a method of labeling containers including the step of forming a frangible region on the label which facilitates de-labeling without unduly weakening the durability of the label.

It is yet another object of the present invention to provide a method of labeling containers with a label that is adapted to break in a frangible region causing it to flag thereby facilitating de- labeling.

According to the present invention a method of labeling containers is provided which facilitates automatic de-labeling of the containers after consumer use . The method includes preparing a container for labeling and preparing a label for application to the container. In the process of preparing the label, a frangible, or breakable, region is formed on the label which may, in some applications, extend across the label generally from the top to the bottom of the label. The label is then applied to the container. The labeled container may then be distributed to consumers for use . The containers are then collected from the consumers for reuse or recycling. A mechanical force is applied to the labeled container to break the label initially at the frangible region prior to separating the label from the container.

The present invention is applicable to a variety of labeling methods including the method wherein labels are fed from a roll which is cut off into label segments. Roll fed label segments are generally applied to the container by tacking the leading end of the label to the container and then wrapping the label around the

container. The trailing end of the label is then secured to the container or the leading end of the label. The method is also applicable to labels that are supplied from a pre-cut stack of labels and applied to the container in a similar manner. The method is even applicable to sleeve-applied labels wherein labels are formed into sleeves and then slid over one end of a container. In each method, the label is either perfo¬ rated or scored prior to application to a container from one edge to the other to form a substantially full height frangible region which permits the label to break from edge to edge. Upon the frangible region breaking, the label flags or extends outward from the container.

The method of the present invention facili- tates de-labeling by means of de-labeling machines which include fluid jet knives, mechanical moving fingers or counter-rotating rollers. Regardless of the de-labeling method used, the method of labeling containers of the present invention improves the operation of the de- labeling machines and their effectiveness at removing labels from containers while minimizing or eliminating damage to the containers inflicted from the de-labeling machine .

Other objects and advantages of the present invention will become more apparent in view of the attached drawings and in light of the following detailed description of the invention.

Brief Description Of The Drawings

FIGURE 1 is a flow chart illustrating the steps of the process of the present invention;

FIGURE 2 is a perspective view of a roll-fed labeling apparatus including a label cutter and a perforator;

FIGURE 3 is a perspective view of a sleeve label being applied to a container;

FIGURE 4 is a perspective view of a cut and stack label magazine applying the label to the contain¬ er;

FIGURE 5 is a perspective view of a label cutter and a perforator for forming a frangible region on a label ;

FIGURE 6 is a perspective view of a fluid knife used to de-label a container at the frangible region on a label;

FIGURE 7 is a plan view of a de-labeling system wherein mechanical fingers are used to break a label at a frangible region and strip it from a contain¬ er; and

FIGURE 8 is a plan view of a bottle de-label- ing apparatus wherein counter-rotating rollers are used to first break the label at a frangible region after which a vacuum label separating device tears the flag¬ ging label from the container.

Best Modes For Carrying Out The Invention

Referring now to the drawings, in Figure 1, the general steps of the present invention are shown diagrammatically with references to the other Figures as

appropπate to illustrate the steps of the invention. As shown m Figure 1, the invention can be used to de- label containers labeled by roll-fed, sleeve-applied, or cut and stack labeling methods. The present invention is not intended for use with pressure-sensitive type labels having adhesive adhering the entire label to the container since the inclusion of a frangible zone on the label would not appreciably improve automatic de-label- mg operations .

Referring now to Figures 1 and 2, a roll-fed labeler 10 is shown wherein a roll of labels 12 are pre¬ printed with label indicia and provided to the roll-fed labeler 10. A web 14 is advanced from the roll of labels 12 to a conventional label cutter 16. A perfora- tor 18 is provided to form a perforated or frangible region on the label . After the cutter 16 cuts individu¬ al segments from the web 14, the label segments are provided to a vacuum drum 20 and then applied directly to unlabeled containers 22 which are fed into the roll- fed labeler 10 The labels are coated on leading and trailing edges with an adhesive or other suitable solvent, paste or glue. The leading edge of the labels are then tacked to the unlabeled containers 22. The labels are then wrapped around the container with the leading edge adhering to the container and the trailing edge adhering to the leading edge to form a labeled container 24 Of course, the trailing edge could adhere directly on the container As can be appreciated, the present invention can also be used with spot or full- wrap labels provided these labels have extensive non- adherent portions which will flag out from the container upon breaking the label at the frangible region or zone .

Referring now to Figures 1 and 3, a sleeve applied label can also be provided with the present invention. A container 30 can be labeled with a sleeve 32 which includes a score line 34. Similarly to the frangible region, the score line 34 facilitates the de- labeling process.

Referring to Figure 4, another approach to labeling that can be used with the present invention is a cut and stack labeling machine. With a cut and stack labeling machine, a magazine 38 is provided with a stack of labels 40. The labels 40 have a frangible region 42 which is a score or perforated line. The frangible region 42 is formed on the labels 40 prior to being loaded into the magazine 38. Labels 40 are applied to containers 44 in accordance with conventional cut and stack labeling techniques.

Referring now to Figure 5, a method of forming a frangible region on a label with a label cutter 48 is shown. The label cutter 48 includes a vacuum drum 50 for supporting the labels. A conventional cutter knife 52 is adapted to cut labels supported by the vacuum drum 50 as it passes the label cutter 48. A perforator 54 is preferably disposed at a circumferentially spaced location from the cutter knife 52 in order to form a fairly long segment of label material having a frangible region between the adherent leading and trailing edges.

Referring now to Figure 1, after the frangible region is formed on the label, the label is applied to the container. Either new or recycled containers can be labeled with any one of the conventional labeling methods described. In many instances, labels are shrink-fitted to the container by applying heat. The

heat causes a film or foam label to contract forming a tight fit on the container.

After labeling, the containers are provided through distribution channels to consumers for consump- tion of the product. Upon consumption, consumers are encouraged to return the containers with deposits or the like for recycling.

The empty labeled containers are collected and supplied to an automatic de-labeling machine. As can be appreciated from the de-labeling methods shown in Figures 6, 7, and 8, various means of applying a mechan¬ ical force to break the label can be provided. In Figure 6, labeled containers 58 having labels including a frangible region 60 are provided to a de-labeler. The de-labeler consists of a fluid nozzle 62 which is used to strip the label from the labeled container 58. Fluid nozzle 62 may direct air or liquid such as water, toward the labeled container 58 with a force sufficient to break or rupture the frangible region 60 but with less force than would be required to split other portions of the label. Breaking frangible region 60 creates a flagging label end 64 which hangs loosely from the container. The label is then easily removed by a label separator. The function of the label separator will be described below.

Another de-labelmg approach is shown in

Figure 7. A labeled container 68 is fed by a conveyor to stripping finger wheels 70 which rotate against the labeled container 68 causing frangible region 72 to split resulting m flagging label ends 74. Again, the

force applied to split the frangible region is less than the force required to split other portions of the label.

Referring now to Figure 8, labeled container 80 may be provided to counter rotating rollers 82. Rollers 82 apply tension to the label by surface contact causing the frangible region 84 to break first resulting in flagging label ends 86. The flagging label ends 86 provide broad surface area upon which the vacuum label separator 88 may act to pull and strip the label from the container. After the label is separated from the container as shown in Figure 1, the label material can be removed and discarded or recycled. The de-labeled container may then be cleaned for reuse and provided again to the label application line to receive a fresh label.

It should be appreciated that a simple and effective method for labeling containers so that they may easily be de-labeled by automatic de-labeling equipment has been disclosed. Applicant has disclosed several different embodiments of the invention to illustrate the invention and to provide an enabling disclosure . The preceding description should not be read in a limiting sense. The present invention should be construed in accordance with the broad scope and spirit of the following claims.