Patent ID: 12202641

The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it should be understood, however, that this invention is not limited to the precise arrangements shown.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The following description of a preferred embodiment of the invention should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

Preferred Embodiment

FIGS.1,3and4show views of an apparatus of a preferred embodiment according to the invention.

Referring toFIGS.1,3and4, an apparatus1is shown for attaching a sleeve-like shrinkable label10on a product12in the form of a bottle. Specifically, the bottle has a shape as shown inFIG.10. The product12is placed on a conveyor14that transports the product12and the label10put loosely over the product12into and through an irradiation volume that is defined by two sets of light emitters16which are arranged opposite each other on both sides of the conveyor14. It is to be noted thatFIG.1only shows one of the two sets of light emitters16. The sleeve-like label10is made of heat-shrinkable material that is caused to shrink when its temperature is increased by irradiation of the light emitters16and thereby getting firmly attached to the product12.

In the preferred embodiment, the two sets of light emitters16are symmetrically arranged with respect to the conveyor14. As shown in the plan view of the apparatus1inFIG.3, the central longitudinal axis22of the conveyor14corresponds to the symmetrical axis of the apparatus1. It is to be noted that the three products12shown inFIG.3picture one and the same product12at three different times. The arrangement of the two sets of light emitters16opposite each other on both sides of the conveyor14encompasses the irradiation volume centered between the opposite sets of light emitters16through which the conveyor14passes and in which the product12placed on the conveyor14is irradiated by the light emitters16. In the preferred embodiment, each set of light emitters16includes four light emitters16.

As shown in the plan views of the apparatus1inFIGS.3and4, the irradiation volume defined by the arrangement of the two sets of light emitters16has a substantially elliptical shape. In other words, in the plan view of the apparatus1, the light emitters16lie on a substantially elliptical curve. With such a configuration, a uniform irradiation and temperature increase of the sleeve-like label10during the exposure period can be achieved. Specially, the substantially elliptical shape improves the temperature distribution in the sleeve-like label10around the circumference of the product12as the product12can be irradiated evenly from all sides while being transported through the irradiation volume.

The light emitters16each comprise a plurality of light sources in the form of UV LEDs positioned in a pattern (not shown in detail in the drawings) and configured to emit directed light bundles18into the irradiation volume through which the product12is being transported on the conveyor14. The plurality of light sources per light emitter16extend in a direction vertically to the conveyor14or the trajectory of the product12placed on the conveyor14that passes horizontally through the irradiation volume. Thus, the sleeve-like label10on the product12can be irradiated over its entire vertical height extensively and uniformly. By using UV LEDs, heat is generated inside of the sleeve-like label10instead of being applied from the outside because the label material is able to absorb the UV light and convert the absorbed UV light into thermal energy.

The directed light bundle18emitted by each UV LED of a respective light emitter16into the irradiation volume is formed of light beams32. As shown inFIG.3, each light bundle18has a specific irradiation direction20a-20d(only irradiation directions of the light bundles18of one set of light emitters16are provided with reference signs), i.e. orientation. The light bundles18are conical divergent light bundles18, wherein in the plan view ofFIG.3, each light bundle18substantially has the form of a triangle and the irradiation direction20a-20dcorresponds to an angle bisector of the triangle. It is to be noted that, only for the reasons of clarity, the light bundles18shown in the drawings are limited by a circular arc in their respective irradiation directions20a-20d.

As shown inFIGS.3and4, intersection points24a-24dof the directions20a-20dof the light bundles18emitted from the light emitters16on a same side of the conveyor14with the longitudinal central axis22of the conveyor14differ from each other. That is, the intersection points24a-24dof the directions20a-20dof the light bundles18emitted from the light emitters16on a same side of the conveyor14with the longitudinal central axis22of the conveyor14are offset from each other along the longitudinal direction of the conveyor14and, thus, along the trajectory of the product12being transported by the conveyor14through the irradiation volume. In other words, in the plan view of the apparatus1ofFIGS.3and4, the light emitters16of one set of light emitters16are directed at different portions of the conveyor belt, wherein the directions20a-20dof the light bundles18differ from each other. With such a configuration, the sleeve-like labels10on the products12can be irradiated uniformly from all sides while being transported on the conveyor14through the irradiation volume without the need to rotate the product on the conveyor14. Due to the specific arrangement of light emitters16and irradiation directions20a-20dof the light bundles18, respectively, light beams32of the light bundles18emitted by the light emitters16can impinge the sleeve surface in a perpendicular direction at a plurality of positions around the circumference of the sleeve-like label10(seeFIG.8) while the product12is transported on the conveyor14through the irradiation volume. Thus, a uniform light irradiation on the sleeve surface can be achieved during the exposure period of the product12inside the irradiation volume which results in a uniform temperature increase of the label. Thereby, a uniform shrinking effect of the label10on the product12can be achieved.

As shown inFIGS.1,3and4of the preferred embodiment, the apparatus1comprises flat side reflectors26made of aluminum sheet metal forming side boundaries of the irradiation volume for reflecting light emitted by the light emitters16into the irradiation volume. The light emitters16and side reflectors26are alternately arranged per set of light emitters16. The side reflectors26further improve a uniform irradiation of the product12inside the irradiation volume by reflecting the light emitted by the light emitters16. In particular, the side reflectors26help to ensure that the product12is irradiated evenly from all sides of the product12(seeFIG.8) so that the temperature of the sleeve-like label10along its circumference can be increased uniformly during the exposure period.

The apparatus1according to the preferred embodiment further comprises a top reflector28and a bottom reflector30arranged so as to constitute a top boundary and a bottom boundary of the irradiation volume, respectively, for reflecting light emitted by the light emitters16into the irradiation volume. Products, in particular bottle-like containers, often have a curved top portion and a curved bottom portion. As shown inFIG.9, by using the top reflector28and the bottom reflector30, light beams32of the light bundles18emitted by the light emitters16are reflected onto the curved top portion and the curved bottom portion of the product12or the label12, respectively. Accordingly, a homogenous temperature profile along the vertical axis of the sleeve material can be obtained. In other words, high temperatures required to shrink the sleeve-like label10reliably onto the curved portions of the product12and thus good shrink results can be achieved.

Method

In the following, a preferred method for attaching a shrinkable label placed on a product, to the product using the apparatus according to the preferred embodiment is described. This method will also be referred to as pulsed mode. Although not shown in the drawings, the apparatus1comprises a controller configured to control the light emitters16to emit light bundles18so as to irradiate the shrinkable label10arranged on the product12in the irradiation volume.

According to the method, as shown inFIG.1, the shrinkable label10placed on the product12is transported on the conveyor14through the irradiation volume of the apparatus1. The light emitters16in the form of UV LEDs are controlled to discontinuously emit light bundles18while the product12is being transported on the conveyor14through the irradiation volume. Thus, the sleeve-like label10placed on the product12is only temporarily irradiated with light emitted by the light emitters16while the product12is being transported on the conveyor14through the irradiation volume. In the preferred embodiment, the two sets of light emitters16include four light emitters16each. In the pulsed mode, the light emitters16are controlled to emit light onto the product12only while the product12is approximately between the two middle light emitters16. In other words, as shown inFIG.3, the light emitters16start to emit directed light bundles18onto the product when the product12placed on the conveyor14has reached the left-most position of the three illustrated product positions, i.e. the intersection point24ashown inFIG.4. Further, the light emitters16stop to emit directed light bundles18onto the product when the product12placed on the conveyor14has reached the right-most position of the three illustrated product positions, i.e. the intersection point24dshown inFIG.4.

Further Embodiments

In the preferred embodiment, the two sets of light emitters are symmetrically arranged with respect to the conveyor. However, a non-symmetrical arrangement of the two sets of light emitters is also conceivable.

In the preferred embodiment, the reflectors are flat. However, curved reflectors as shown inFIGS.2,5and6are also conceivable.

In the preferred embodiment, the light emitters are UV LEDs. However, the light emitters16may be mercury lamps or halogen lamps. Such lamps emit polychromatic light instead of monochromatic light. Further, such lamps possess a higher efficiency and higher robustness in comparison to LED light emitters. The output power of mercury lamps and halogen lamps is very high and they are cheaper compared to LED light emitters.

As a further alternative, the light emitters may be IR lamps. IR lamps are common as high power lamps and cheaper in comparison to UV light emitters.

As described above, according to the preferred method, the light emitters are controlled to discontinuously emit light bundles while the product is being transported on the conveyor through the irradiation volume. Specifically, the light emitters are controlled to emit light onto the product only while the product is approximately between the two middle of the four light emitters of each set of light emitters. However, depending on the form of the product, the irradiation pulse of the light emitters may also start earlier or later and may end earlier or later.

Further, according to another method which will also be referred to as continuous mode, the controller may be configured to control the light emitters to continuously irradiate the shrinkable label while the product is conveyed through the irradiation volume. According to the continuous mode, the sleeve-like label placed on the product starts to get exposed to the light emitted by the light emitters when the product enters the irradiation volume and the exposure ends when the product placed on the conveyor leaves the irradiation volume.

REFERENCE SIGNS

1apparatus10label12product14conveyor16light emitter18light bundle20a-20ddirection22longitudinal central axis24a-24dintersection point26side reflector28top reflector30bottom reflector32light beam