PACKAGE FOR PAPER SHEETS

Abstract

This invention relates to a package (1) for sheet material such as paper intended for printing or photocopying use, in which package a set of paper sheets (12) is placed within a continuous protective wrap (2). The package (1) is arranged to be placed in a machine that uses paper sheets (12) essentially as a whole bundle, with only a small part of the wrap (2) removed.

Description

This invention relates to a package for sheets of paper such as printing and photocopy paper, as described in the preamble to claim 1.

In known technology, office paper provided in sheet form, such as A4-sized photocopy and printing paper, is usually packaged in corrugated board boxes, each box containing five paper packages wrapped in individual paper wrappings. Each paper package, known as a ream wrap, contains 500 A4-sized sheets of paper. Usually the smallest sheet paper bundles for sale consist of the abovementioned 500 sheets. One problem with paper bundles packed in this way is the relatively large amount of paper when used with desktop printers, faxes and photocopiers. When the ream wrap is opened, only half or less of the package can be used at a time. Most desktop printers use very little paper. This means that paper sheets removed from their wraps can get dry or change their properties over time due to lack of use and lack of protection from the wrap. Drying can lead to increased static electricity in the paper sheets and to the sheets sticking to each other, which causes printing problems or blockages in the paper line of the printer or other paper-using machine.

The object of this invention is to remove the problems described above and achieve insofar as possible, an inexpensive and easy-to-use package for printing and photocopy paper, suitable for use with desktop printers and other relatively low-volume uses. The purpose of the invention is also to achieve a package for printing and photocopy paper that can be placed inside the machine that uses paper sheets with the protective wrap partly in place, which will protect the sheets from drying and otherwise changing their properties in the machine. The package described in the invention is characterised by what is disclosed in the characterisation part of claim 1. Other embodiments of the invention are characterised by what is disclosed in the other claims.

The benefit of the solution according to the invention is that the package is very cheap and quick to produce. Another benefit is that the packaging material has high bursting and tear resistance, so the package protects the paper sheets inside it from mechanical stress. A further benefit is that the packaging material is available in reels, which minimises the amount of wastage. Another benefit is that the wrapping uses very little or no plastic, which makes it environmentally friendly and cheap to recycle. Another benefit is that the wrapping is very resistant to moisture, even though there is no separate plastic layer. Another benefit is that the wrap is provided with at least one opening strip, which makes the wrap easier to open. Another benefit is the suitable amount of paper sheets for household use, and the fact that the package can be placed whole into the printer or photocopier with the moisture-repellent protective wrap still partly in place, which means that if they are used slowly, the paper sheets do not dry too easily or change their other properties too quickly. A further benefit of the solution according to the invention is that some of the easily breakable parts that guide paper sheets in the machines that use paper can be left out, which allows the machines to be more affordable, simpler, more reliable and more maintenance-free than known small-scale printers and photocopiers.

Below, the invention is described in detail using application examples, by referring to the appended figures, in which

FIG. 1 shows a package according to the invention viewed diagonally from the side,

FIG. 2 shows a package according to FIG. 1, viewed diagonally from the side and with one end removed from the opening strip onwards,

FIG. 3 shows a typical layer structure for the protective wrap according to the invention, in simplified and enlarged form,

FIG. 4 shows another layer structure for the protective wrap according to the invention, in simplified and enlarged form,

FIG. 5 shows a third layer structure for the protective wrap according to the invention, in simplified and enlarged form,

FIGS. 1 and 2 display a paper sheet package 1 according to the invention, containing A4-sized paper sheets in a smaller quantity than ordinary ream wraps, which have 500 sheets. The number of paper sheets can be for example approx. 100-400, suitably e.g. 200-300 and favourably e.g. 250, which is an easy quantity to set when producing ream wraps containing 500 sheets. The paper sheets 12 are packed inside a package 1 made out of a strong protective wrap 2. The package is made out of a reel-based wrap 2, which wrap 2 is pulled directly off a reel during the production of the package 1, and cut off at the correct length, after which the wrap 2 is rolled around for example paper sheets 12, such that the top, bottom and both long sides of the package form a continuous wrapper, in which the back end 8 of the wrap 2 overlaps the forward end 7 of the wrap by a suitable amount and is glued down by its inner surface to the outer surface of the forward end 7. The hidden forward end 7 of the wrap 2 is indicated using a dashed line. The back end 8 of the wrap 2 is placed suitably on top of the grouped package, essentially close to one of its long corners. At each end of the package 1 there are at least outer folds 3 and 4 and inner folds 5 and 6, which folds are placed at least partially overlapping and glued together suitably. The folds at the ends form a strengthened protection for the ends of the office paper sheets in the package, where even a small accident could easily cause damage to several sheets.

FIG. 1 also has a dashed line indicating an opening strip 10, glued to the inner surface of the wrap 2 before the wrap is cut-off. Thus the opening strip 10 is essentially the same length or suitably longer than the wrap 2. The opening strip 10 is placed at a suitable horizontal distance from the end of the grouped package 1. A suitable distance is for instance one which leaves the ends 13 of the paper sheets 12 in the package 1 only just visible enough after the wrap 2 is opened that the printer or photocopier can get a good hold of the end 13 of the topmost sheet. The rest of the sheets remain protected within the larger part of the wrap.

At the ends of the opening strips 10, in line with the end 8 of the wrap 2, the edge of the wrap is cut open such that at each side of the opening strip 10 is a suitably long incision 11, lengthwise in line with the opening strip 10. This makes it easy to get hold of the end of the opening strip 10, and the wrap 2 can be torn open right around the package 1, crosswise in relation to the positioning of the paper sheets 12. The material of the opening strip 10 can vary, but it is always sufficiently strong and essentially inelastic or very slightly elastic.

FIG. 2 displays a package 1 according to FIG. 1, opened at the opening strip 10. Here the opening strip 10 has been torn open and one end of the wrap 2 has been removed, leaving a section 2a of the wrap 2 over the package 1, covering almost all of the package, which section 2a is designed to protect the paper sheets 12 from moisture and other changes while in the printer or photocopier. A package thus opened at one end is designed to be lifted as a single pile or bundle contained within the remaining section 2a of the wrap, into the machine.

The wrap 2 according to the invention must fulfil certain requirements related to protectiveness, bursting strength, tear resistance, gluability and printability. In addition, the wrap 2 must protect the contents of the package from moisture. Thus the material of the wrap 2 can for example be formed such that the base layer 15 consists of paper, to which an additive is added during production through online coating in the paper machine's coating section, which additive consists of plastic, a polymer mixture or a similar suitable material 16 that slows down moisture absorption, in a suitable quantity that the water vapour transmission rate (WVTR) of the wrap 2, calculated according to the ISO 2528:1995 standard, is less than approximately 50 g/m²/d, preferably a maximum of 30 g/m²/d and favourably a maximum of 10 g/m²/d. Such polymers or polymer mixtures added during the paper's production process are for example latex and various mineral mixtures.

According to one of the embodiments of the invention, the wrap 2 that forms the package 1 is smooth, so that it can be coated in plastic more easily. In this case the wrap is coated at least on one side with a plastic film using a separate extruder, as is done in some known solutions. Thanks to the smoothness of the paper, less plastic has to be used than before. Suitable plastic films for this purpose include polyethylene (PE) films, polyethylene terephthalate (PET) films and polypropylene (PP) films.

A further embodiment of the invention consists of the combination of the two embodiments described above. In this solution, the wrap 2 consists of paper to which a polymer mixture has been added during production in the paper machine's coating section, after which a plastic film is added to the paper in a separate extruder.

The materials and thicknesses of the different layers of the wrap 2 are chosen so that the end result in each of the embodiments of the invention described above is a wrap in which the total quantity of plastic out of the overall layering of materials makes up less than 10% of the total weight of the wrap 2. Favourably, the total quantity of plastic is a maximum of approx. 5% of the total weight of the wrap 2. This makes the wrap environmentally friendly and more recyclable, with reduced recycling costs.

FIG. 3 shows the layer structure of one of the wraps 2 according to the invention, simplified to show only the essential layers. In addition, the thicknesses of the layers are not to scale. The base of the wrap 2 consists of a base paper layer 15. Depending on the type of paper, the base paper layer 15 can have one or more layers. Only one layer is shown in the figure for simplicity. On top of the paper layer 15 is a printing ink layer 14, which covers the surface of the paper layer 15 at least partially. On the other side of the paper layer 15, is a polymer layer added during the paper's production as online coating, or a similar layer 16 that slows down the penetration of moisture.

FIG. 4 shows a similar structure to that in FIG. 3, but the layer of polymer or similar material 16 that slows down the penetration of moisture is placed in between the printing ink layer 14 and the paper layer 15. Therefore the printing is done onto layer 16, which must be suitable for printing. In addition, an essentially thin plastic film 17, such as a PE, PET or PP film, has been added to the wrap 2 in an extruder.

FIG. 5 shows the layer structure of a third wrap 2 according to the invention, simplified to show only the essential layers. In addition, the thicknesses of the layers are not to scale. The layer structure is similar to that in FIG. 3. In this structure, a surface layer 18 is added to the top of the base paper layer 15, which surface layer can be fused using heat or ultrasound. In this case, instead of using separate glue, all seams that are normally glued can be produced by heat sealing or ultrasound. The printing ink layer 14 does not have to go over the seams that will be fused.

The layering and, particularly, the thickness of the wrap 2 can be used to regulate how resistant the paper bundles inside the package 1 are to blows and strokes from the outside. At least the thickness of the wrap 2 should be such that the weight of the wrap is in the range 60-250 g/m². Depending on the wrap material, a suitable thickness range, expressed in weight, is 80-160 g/m². The thickness can also be such that the weight is 120-150 g/m².

Those skilled in the art will see that the invention is not limited to the example given above, but can be varied within the scope of the patent claims given below. The protective wrap does not have to come off a reel for the production of the package, but can be in ready-cut sheets.

Further, those skilled in the art will see that the wrapping of the protective wrap around the package can be done in many different ways, as can the gluing of the folds at the ends of the package.

Further, those skilled in the art will see that instead of a wrap, other kinds of protective structures than those mentioned above can be used. For example wraps consisting of nonwoven fabric or other similar thin protective materials can be used in the solution according to the invention.

Those skilled in the art will also see that the wrapping materials do not have to contain any plastic, if substances that make the material suitably hydrophobic are added for example to the base paper layer at the time of the paper's production.

Further, those skilled in the art will see that the size of the paper sheets can differ from the abovementioned A4 size. The paper sheets can be larger, smaller or differently shaped than A4 sheets.

Further, those skilled in the art will see that the number of paper sheets in the package can vary from the proposed quantities of either 100-400 or approximately 250 sheets. The number can be greater or smaller or even equivalent to that of a ream wrap (approx. 500 sheets).

Claims

1. A package (1) for sheet material such as paper intended for printing or photocopying use, in which package (1) a set of paper sheets (12) is placed within a continuous protective wrap (2), characterised in that the package (1) is designed to be placed into a machine that uses paper sheets (12) essentially as a single bundle, with essentially only a small part of its wrap (2) removed.

2. A package (1) according to claim 1, characterised in that the package (1) contains an opening strip (10) that surrounds the package in cross-wise fashion in relation to the position of the paper sheets (12), which opening strip (10) is placed close to one end of the package (1), and in that the paper sheets (12) are designed to be lifted as a single bundle into the paper tray of a machine that uses paper, with one end of the wrap (2) removed.

3. A package (1) according to claim 1 or 2, characterised in that an essentially larger part (2a) of the wrap (2) is designed to be placed together with the paper sheets (12) in the machine.

4. A package (1) according to claim 1, characterised in that the package (1) contains approximately 200-300 sheets, optimally approx. 250 sheets.

5. A package (1) according to above claim 1, characterised in that the water vapour transmission rate (WVTR) of the wrap (2), calculated according to the ISO 2528:1995 standard, is less than approx. 50 g/m2/d, suitably a maximum of approx. 30 g/m2/d and favourably a maximum of approx. 10 g/m2/d.

6. A package (1) according to above claim 1, characterised in that a maximum of 10%, favourably a maximum of approx. 5% of the total weight of the wrap (2) consists of plastic.

7. A grouped package (1) according to above claim 1, characterised in that plastic, a polymer mixture or another similar material that slows down the penetration of moisture is added to the wrap (2) using the online method during the production of the wrap (2) in a paper machine.

8. A grouped package (1) according to claim 2, characterised in that the wrapping that forms the package's (1) protective wrap (2) is taken directly from a reel when wrapping the package (1) and wrapped at least once around the long sides of the package (1).

9. A package (1) according to claim 2, characterised in that the package (1) contains approximately 200-300 sheets, optimally approx. 250 sheets.

10. A package (1) according to claim 3, characterised in that the package (1) contains approximately 200-300 sheets, optimally approx. 250 sheets.

11. A package (1) according to claim 2, characterised in that the water vapour transmission rate (WVTR) of the wrap (2), calculated according to the ISO 2528:1995 standard, is less than approx. 50 g/m2/d, suitably a maximum of approx. 30 g/m2/d and favourably a maximum of approx. 10 g/m2/d.

12. A package (1) according to claim 3, characterised in that the water vapour transmission rate (WVTR) of the wrap (2), calculated according to the ISO 2528:1995 standard, is less than approx. 50 g/m2/d, suitably a maximum of approx. 30 g/m2/d and favourably a maximum of approx. 10 g/m2/d.

13. A package (1) according to claim 4, characterised in that the water vapour transmission rate (WVTR) of the wrap (2), calculated according to the ISO 2528:1995 standard, is less than approx. 50 g/m2/d, suitably a maximum of approx. 30 g/m2/d and favourably a maximum of approx. 10 g/m2/d.

14. A package (1) according to claim 2, characterised in that a maximum of 10%, favourably a maximum of approx. 5% of the total weight of the wrap (2) consists of plastic.

15. A package (1) according to claim 3, characterised in that a maximum of 10%, favourably a maximum of approx. 5% of the total weight of the wrap (2) consists of plastic.

16. A package (1) according to claim 4, characterised in that a maximum of 10%, favourably a maximum of approx. 5% of the total weight of the wrap (2) consists of plastic.