The present invention relates generally to the embossing of paper or laminated metallic foil. More specifically, the invention relates to an apparatus and a method for roll to roll embossing of paper or laminated metallic foil.
Paper sheets and sheets of paper laminated with metallic foil are used in a variety of wrapping and packaging applications. Consumer items, such as confectionery, are often wrapped individually or in bundles in such paper or foil sheets, and cigarettes and cigars are often sold in tins or boxes lined with such foil sheets. Laminated metallic foil sheets are particularly useful as package liners for tobacco products because the metal foil forms a barrier to light and moisture which could degrade the tobacco.
Laminated metallic foil sheets and paper sheets used as wrappers or packaging liners are often embossed to show images such as patterns, trade marks, company names, logos, or other information in order to enhance the presentation of goods wrapped or packaged with such sheets. The embossing may be carried out by well-known processes such as roll to roll embossing, in which a strip of laminated foil or paper is fed and pressed between a pair of embossing rollers.
For example, it is well known in the tobacco industry to use an embossing technology based on passing a laminated metallic foil through a press having two hardened steel embossing rollers, one being a drive roller and the other being driven by the drive roller. In one technique, the embossing rollers are each initially machined with mating die patterns consisting of an array of small pyramidal projections that extend over the entire roller surface. The pyramidal projections act as embossing dies to produce a pattern as the sheet passes between the rollers. In order to create images appearing on the embossed sheet, the pyramidal projections of the drive roller are partly or completely removed in areas that reflect the shape of the image to be depicted. Once embossed, the metallic foil sheet bears the pattern of the pyramidal die array everywhere except for the areas corresponding to the images. The images are thus produced by leaving part of the sheet unembossed while the embossed pattern provides a background for the images. In the present specification, therefore, it will be understood that the term “embossed image” includes an image created by embossing a background pattern that surrounds an unembossed image area.
The embossing rollers used for this type of embossing technique are normally dedicated to a single product line for which the rollers can produce an embossed strip of laminated foil or paper which is then cut into uniform sheets. All of the sheets so produced look exactly the same, bearing the same embossed background pattern and images. Consequently, when a product is to be packaged with sheets bearing different images, for example sheets having written matter in different languages, it is necessary to use different sets of embossing rollers. Each time embossed sheets having different appearances are to be produced, one set of embossing rollers must be switched in the press for another set of embossing rollers. Alternatively, other production lines must be set up with additional embossing presses having different sets of embossing rollers. This is a disadvantage because additional manufacturing costs must be incurred to produce embossed sheets with different images. In the first case, the cost is due to lost production caused by production down time while the embossing rolls are changed. In the second case, the cost is for additional presses and other equipment.
There is therefore a need for an embossing technique that provides added flexibility in the production of different images or embossing patterns on sheets of paper or laminated metal foil.
It is an object of the present invention to provide an apparatus and method for producing paper or laminated metal foil sheets with different embossed images that do not have the shortcomings of the prior art.
In accordance with a first aspect of the present invention, there is provided an apparatus for producing embossed sheets. The apparatus comprises means for feeding an elongate strip of paper or laminated metallic foil, first and second embossing rollers disposed to receive such a strip from the feeding means, and means for receiving such a strip from the embossing rollers after being embossed thereby, and for cutting such strip into sheets. The first roller has a plurality of embossing die sectors arranged on the surface thereof. At least one of the sectors imparts a first embossed image, and at least another of the die sectors imparts an alternate embossed image different in appearance from the first embossed image. The die sectors are dimensioned similarly to the foil sheets. At least one group of the sheets thus carries the first embossed image while at least another group of the sheets carries the alternate embossed image. The embossing die sectors may be arranged axially along the embossing rollers or circumferentially around the embossing rollers, or both axially and circumferentially. The second embossing roller may also have a plurality of embossing die sectors arranged on the surface thereof arranged to match with embossing die sectors of the first embossing roller.
In accordance with another aspect of the present invention, there is provided a method of producing embossed laminated metallic foil or paper sheets. One step of the method is to emboss a strip of paper or metal foil with at least two groups of die sectors. Each group of die sectors embosses a different image. The strip is then cut into sheets according to the different embossed images.
In accordance with yet another aspect of the present invention, there is provided a batch of a production run of paper or metallic foil sheets for packaging cigarettes. The batch comprises a plurality of embossed sheets having been cut from the same strip. At least one group of the sheets carries a first embossed image, and at least another group of the sheets carries an alternate embossed image.
The present invention thus permits the use of a single production line concurrently to produce paper or laminated metallic foil sheets with different embossed images.
These and other features of the present invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
The present invention is useful to emboss different images on paper or metallic foil. The invention is compatible with different embossing techniques. For example, the embossing may be performed using a first roller made of a hard material such as steel and a second roller coated with a smooth soft coating such as deformable plastic. Another embossing technique uses two embossing rollers having matching image patterns. In this latter technique, an image is created either by the embossment itself or by embossing a background pattern that surrounds the image.
An embodiment of the present invention for producing laminated metallic sheets of a size suitable for use in a pack of cigarettes will now be described. The embossing apparatus 1 shown in
Both the first and second rollers 5 and 10 are rotatably mounted in a frame 30. The first roller 5 may be driven at an appropriate speed through a motor/gearbox assembly 35. The mechanical assembly of the components in the frame of the apparatus can be any of several conventional designs known to those skilled in the art.
The second roller 10 is driven by the first roller 5 through gears 40, which ensures synchronized rotation of the two rollers. Other synchronization means could also be used. For instance, in some situations the matching dies 15 could be sufficient to ensure synchronization between both rollers 5 and 10.
A cutting station 45 is provided to receive and cut an embossed strip of laminated metallic foil 20 into sheets 55 after exiting the rollers 5 and 10. The cutting station 45 is equipped with a longitudinal cutting mechanism 60, a lateral cutting mechanism 65 and synchronizing means 70.
The rollers 5 and 10 are driven while the strip of laminated metallic foil 20 is inserted between them. The pressure and the distance between the two rollers 5 and 10 may be adjusted such that the matching dies 15 engage each other for proper embossing of the strip of laminated metallic foil 20.
During the embossing operation, the strip of laminated metallic foil 20 is passed between the rotating rollers as shown in
By carefully synchronizing the cutting station 45 with the rollers 5 and 10, the strip of laminated metallic foil 20 may be cut to generate the sheets 55, embossed with different images. Although the synchronizing means 70 is depicted as a chain in
Alternatively, the cutting station 45 could be electronically synchronized with the embossing station 3 through a controller monitoring, through sensors, either the rotation speed of the rollers 5 and 10 and actuating the cutting station 45 accordingly or by monitoring the embossed patterns in the strip of laminated metallic foil 20 and activating the cutting station 45 such as to precisely cut the sheets 55.
Turning now to
The roller shown in
The person skilled in the art would readily understand that various sectors 75 could be arranged either circumferentially or axially on a set of matching rollers. Placing more sectors 75 circumferentially may increase the diameter of the rollers while placing more sectors 75 axially may increase the width of the rollers. Images can be oriented in any direction to suit the orientation of the sheet 55 on the strip of laminated metallic foil 20.
When the rollers used have two or more die image sectors 75 arranged side-by-side parallel to the longitudinal axis, the cutting station is equipped with the longitudinal cutting mechanism 60. When the strip of laminated metallic foil 20 is only one image wide and the rollers 5 and 10 only have one image die in width, the cutting station 45 is not required to have the longitudinal cutting mechanism 60.
The rollers may have an image die array made up of many different image dies in the various sectors 75, with some of them being present in more than one section on the roller. This allows having a larger proportion of a certain type of image in a production batch.
In use, the strip of laminated metallic foil 20 is fed through the first and second roller 5 and 10 having matching image dies 15. The rollers are placed against each other adequately to properly emboss the strip of laminated metallic foil 20. The rollers 5 and 10 are synchronized with each other through any suitable means. Subsequent to the embossing, the cutting operation is performed by the cutting station 45, synchronized with the embossing station 3 such that sheets 55 are created bearing different embossings as created by the different sectors 75 of the rollers 5 and 10.
It is further possible to use a sorting station after the cutting station. The sorting station sorts the sheets 55 according to the embossing appearing on them. This is accomplished, for example, by having sectors 75 arranged axially along the rollers 5 and by having gates or separators placed at the exit of the cutting station 45 such that sheets 55 are sorted automatically, depending on their lateral position at the exit of the cutting station 45. By using the sorting station in combination with rollers having different sectors 75 arranged both axially and circumferentially, it is possible to produce sheets 55 having different appearance for different products. For example, if rollers 5 have 4 sectors arranged axially and two sectors arranged circumferentially, it is possible to produce two types of sheets 55 having different appearances for four different lines of products.
The present invention is compatible with different embossing techniques. For example,
The present invention has been described with regard to preferred embodiments. The description as much as the drawings were intended to help the understanding of the invention, rather than to limit its scope. It will be apparent to one skilled in the art that various modifications may be made to the invention without departing from the scope of the invention as described herein, and such modifications are intended to be covered by the present description.
This application is a National Stage Entry entitled to and hereby claims priority under 35 U.S.C. §§365 and 371 corresponding to PCT Application No. PCT/EP2008/054059, titled, “Apparatus and method for producing embossed paper or laminated metallic foil sheets,” filed Apr. 3, 2008, which in turn claims priority to United States Provisional Patent Application Serial No. 60/910,306, filed Apr. 5, 2007, all of which are hereby incorporated by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP2008/054059 | 4/3/2008 | WO | 00 | 2/1/2010 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2008/122589 | 10/16/2008 | WO | A |
Number | Date | Country |
---|---|---|
1609587 | Dec 2005 | EP |
1658965 | May 2006 | EP |
1897682 | Mar 2008 | EP |
WO 03086743 | Oct 2003 | WO |
WO 2006092817 | Sep 2006 | WO |
Number | Date | Country | |
---|---|---|---|
20100129681 A1 | May 2010 | US |
Number | Date | Country | |
---|---|---|---|
60910306 | Apr 2007 | US |