Background Binders for storing papers and other articles are well known in the art. Typical binders include a ring binder mechanism that includes a base to which is connected a plurality of rings.

Outer covers are constructed from a variety of materials and in a variety of ways.

Common materials used in the construction of outer covers are synthetic, plastic- synthetic, and plastic-type, such as solid plastic or a thin plastic.

US 5,585,445 describes a ring binder composed of a pair of thermoplastic sheets superimposed in edge-to-edge relation with a stiffener insert panel. The peripheral edge portions of the two thermoplastic sheets are sealed together and provide a sealed envelope for the stiffener insert. The patent describes the use of synthetic plastic material for the two sheets, such as ethyl-vinyl-acetate polymer, a poly-vinyl- chloride polymer or a polyolefin.

US 5,857,797 discloses a ring binder having an outer plastic shell including a rectangular picture frame, the outer edges of which are aligned with and welded to the bottom and side edges of the spine and cover.

Thus, the prior art ring binders are made from several layers of plastic material wrapped around a stiff insert, and in case of ring binders with pockets additional layers have been provided leading to an increased environmental problems when the ring binders are discarded.

The explosion in the use of plastics has created certain environmental concerns.

Consumers'desire for products constructed of biodegradable materials is on the rise. Also, recyclable materials are gaining an increasing measure of acceptance in

the marketplace. Thus, there is a need for a binder consisting of biodegradable materials yet having the functionality of the plastic binders.

Summary of the invention Accordingly, it is an object of the present invention to provide a binder being made from materials having less impact on the environment which is obtained by a binder comprising: stiffener insert (s) interconnected to form at least a front panel, a back panel and a spine panel said panels having an exterior surface and an interior surface, an outer cover substantially covering at least the exterior surface of the panels, said outer cover being secured to the panels leaving at least one open side unsecured for insertion of material, optionally a ring mechanism fixed to the interior surface of any of the panels, and optionally an inner cover of another material than the outer cover.

The binders according to the invention comprises fewer layers as compared to prior art window/pocket ring binders. The ring binder according to the invention is preferably of the kind comprising a front and a back connected by a spine part, which kind of binders will be discussed in the following. However the invention is also applicable to binders comprising more parts, such as a top part or a side part to be folded into the binder. Furthermore, the invention relates to binders in the form of cassettes or folders for magazines, etc, wherein the cassette or folder is folded to its three-dimensional shape from the binder.

Secondly it is an object of the present invention to provide a method for producing such a ring binder, additionally wherein the method is time and energy saving which is provided by a method of producing a ring binder comprising: providing stiffener insert (s) interconnected to form a front panel, a back panel and a spine panel said panels having an exterior surface and an interior surface,

arranging an outer cover adjacent to the exterior surface of the panels securing the outer cover to the panels leaving at least one open side unsecured for insertion of material, optionally attaching an inner cover to at least the interior surface of the panels, and optionally attaching a ring mechanism to the interior surface of any of the panels.

Drawings Fig. 1 shows a part of the binder including a corner seen from the interior side of the panels.

Fig. 2 shows the same view as Fig. 1 further showing the position of an inner cover.

Fig. 3 shows a cross section corresponding to A-A of Fig. 2 showing the layer of the binder.

Detailed description of the invention The ring binder is generally constructed from a stiffener insert, an outer cover and optionally an inner cover.

Inserts The stiffener insert is made from a material securing the shape and rigidness of the ring binder. The stiffener inserts form the front panel, the back panel and a spine panel of the ring binder. The inserts may be made from three independent inserts interconnected to form said panels. The panels may be interconnected by means of a layer of web material or the like. In a preferred embodiment the inserts are formed from a one-piece insert bearing two grooves, wherein the material of the bottom of the grooves is the panel-connecting material. The grooves divide the one-piece

insert into the three panels discussed above. The material of the bottom of the grooves is preferably the same material as the panels.

The material of the panels is preferably a moisture absorbing material, whereby the panels may absorb any moisture of a glue applied to the panels. A preferred material is paperboard of a sufficient stiffness, such as paperboard of from 800 g/m2 to 1700g/m2, more preferred from 1000g/m2 to 1500g/m2. The stiffness of the material may be proportional to the thickness of the material depending of the nature of the material chosen. The material must preserve the shape and rigid properties of the binder when in use for a prolonged period of time without bending or folding inadvertently.

Exterior surface The exterior surface of the panels may be provided with an outer layer, for example for decorative purposes. As for the panel material the outer layer is preferably a moisture absorbing material and furthermore, in view of the environmental aspects of the ring binder, the outer layer is preferably made of paper material, such as paper from 90 g/m2 to 180 g/m2. The outer layer is preferably a coloured paper layer. When using an outer layer the layer is preferably permanently attached to the exterior surface of the panels, such as glued using for example a hot glue, such as an animal hot glue.

In one aspect of the invention the exterior surface of the panels or in case of an outer layer the exterior surface of the outer layer comprises at least partially a glue material having glue effect when wetted, preferably the exterior surfaces of all panels comprises the glue material. The glue may be selected from the group consisting of hot glues, such as animal hot glues.

An important feature of the present invention is how the glue material after drying is capable of providing a sticky texture, upon contact of liquid with the glue material.

For the purpose of the invention this provides a material where upon other materials, such as any type of display may be adhered. The invention thus offers the possibility of inserting a display to be attached permanently to the exterior surface.

Outer cover According to the invention the outer cover substantially covers at least the exterior surface of the panels, said outer cover being secured to the panels leaving at least one open side unsecured for insertion of material, such as display material.

In the present context the term"substantially"means that most of the exterior surface of the panels is covered, however the invention allows for smaller parts of the exterior surface not being covered by the outer cover.

By the term at least the exterior surface is meant that the outer cover is allowed to cover a part of the interior surface of the panels as well.

The outer cover is provided for protection of the binder as a whole thereby increasing the lifetime of the binder. Furthermore, the function of the outer cover is to provide the outer layer with a pocket for inserting material.

In another aspect of the invention the outer cover of the ring binder is made from an at least partly transparent material. In the present context the term"partly transparent"means that at least a part of the outer cover, for example a part covering the front panel is transparent whereby any material in the pocket is displayed.

In one embodiment the outer cover material of the ring binder is a material having water barrier properties. By the term"water barrier properties"is meant a material capable of rejecting a liquid, thereby ensuring the protection of the content of the ring binder. Furthermore, the water barrier properties protect the glue layer of the exterior surface of the panels to be inadvertently wetted.

The outer cover is preferably made from a plastic material, preferably a biodegradable plastic material, such as polyethylene or polypropylene. However other plastics are also suitable, such as PVC foils.

By the term"leaving at least one side open"is meant to include that the outer cover is secured to the panels except for an opening that allows for material to be inserted into the pocket arising between the outer cover and the panels. It is preferred that the pocket is as large as possible, such as corresponding to the entire area of the exterior surface of the panels, whereby the outer cover of the ring binder is preferably secured to the peripheral parts of the interior panel surfaces apart from the top peripheral part of at least the front panel. However to obtain the total advantage of the pocket the outer cover is preferably not secured to the top part of any panels.

By providing a pocket in the full length of the top peripheral part of the ring binder, and furthermore providing the exterior surface with a sticky texture when wetted it is possible to arrange a display material anywhere in the pocket and ensure that the material will stay at the predetermined location. Thereby the prior arts pockets of predefined size and position is avoided, leading to an independency allowing for a greater choice of freedom of design, and may lead to many different physical creations and external appearances of the ring binder. The consumer may now create any size of display material of course within the boundaries of the ring binder and have it situated precisely in relation to the edges of the ring binder.

The outer cover may be attached directly to the interior surface of the panels, however due to the difference of the preferred materials for outer cover and inserts, respectively, it is often necessary to provide for additional attachment.

Accordingly, in another aspect of the invention an inner cover of the ring binder is attached to the inner surface of the panels and to the part of the outer cover secured to the interior surface of the panels. The inner cover is made from a material different from the outer cover.

In yet another embodiment of the invention the inner cover of the ring binder is securing the outer cover to the interior surface of the panels.

The inner cover is preferably made from a biodegradable material, such as a paper material. The inner cover material of the invention may be selected from paper of from 90 g/m2 to 180 g/m2.

As may be seen from the discussion above, the binder may be made from fewer layers than prior art ring binders, and furthermore, although the materials chosen for- the binder may be any materials, it is possible and preferred to chose biodegradable materials for the binder. The binder may be used as a ring binder comprising a ring mechanism or as a binder as such whereby the content of the binder is merely situated and protected by the binder without being anchored by rings.

The ring binder according to the invention may be of any size or form suitable for the size of material to be protected and held by the binder.

Ring mechanism In case of a ring binder any suitable ring mechanism may be attached to the interior surface of the panels or of the inner cover. The ring mechanism may be attached by any means known to the person skilled in the art.

The ring mechanism may thus comprise at least one ring, such as two, three or four rings. Each ring is typically comprised of two semi-circular prongs that are mated at one point to form a generally circular ring. The non-mating end of each prong is connected to the base of the ring binder mechanism. At this connection point, each prong of each ring is hinged to rotate in opposite directions. Thus, the mating ends of each ring can be separated at the mating point to allow the insertion of papers or other articles onto the ring for storage within the binder.

The base of the ring mechanism is preferably attached to the back panel, in particular the part adjacent to the spine panel.

The attachment means of the ring mechanism may pass through all layers of the ring binder including the outer cover. In order to obtain a large pocket it is however preferred that the outer cover includes punchings or holes corresponding to the attachment means.

The invention further relates to a method of producing the ring binder according to the invention. The ring binder of the invention is preferably made in an automated process wherein the stiffener insert (s) in the dimension of the final panels as

discussed above is provided. An outer cover, also discussed above, is arranged adjacent to the exterior surface of the panels in a manner whereby the outer cover may be secured to the panels in a next step of production.

The outer cover is preferably temporarily attached to the insert (s) by means of an adhering substance, such as a glue. The glue is preferably a hot glue, such as an animal hot glue. The adhering effect of the hot glue is to attach the outer cover to the panels and keep the outer cover in place until it has been permanently secured to the panel leaving at least one open side unsecured for insertion of display material. The glue may be applied to a part of the outer cover, however it is preferred that the glue is evenly applied to the whole outer cover.

Due to the preferred choices of material for the panels and the outer cover, the hot glue will be absorbed by the panel during or shortty after the production of the binder, whereby a pocket is formed between the outer cover and the panels. The pocket may be reached from the open side to insert display material, for example.

The absorbed glue preferably maintains a glue effect when the exterior surface is wetted, for example by applying a wetted display material to the exterior surface.

The dimensions of the outer cover are preferably slightly bigger than the dimensions of the outer contour of the three panels. Thereby the outer cover may be secured to the panels by folding a part of the outer cover around the outer edges of the panels and having the outer cover attached to the interior surface of the panels, yet leaving one side open for the pocket.

In a preferred embodiment the inner cover is provided and fixed to the interior surface of the panels and to the part of the outer cover secured to the interior surface of the panels. More preferred the inner cover is the means for securing the outer cover to the interior surface of the panels.

The inner cover is preferably fixed by means of an adhering substance such as a glue. Any suitable glue capable of adhering to the outer cover may be used, such as a PVA glue. In order to enhance the adhering effect of the glue used for attaching the inner cover in particular to the folded part of the outer cover, the outer surface of the outer cover may be treated. Preferably the outer cover is corona treated on the

outer surface, whereby the giue more readily and lastingly will adhere to the outer cover. It is important when using corona treatment to assure that the inner surface of the outer cover does not receive any treatment, since this would lead to a production problem in the creation of the pocket.

In one embodiment the panels are provided with an outer layer before the outer cover is arranged. The cover is then temporarily attached to the outer layer instead of directly to the panels. The outer layer may be provided for decoration purposes making the ring binder more appealing, such as when the outer layer is coloured.

When a paper outer layer is provided it is of importance that the machine direction of insert material as well as of the outer layer is the same, and more preferred that the machine direction is the broad machine direction.

The optional ring mechanism is attached to the ring binder according to any suitable process known to the person skilled in the art, after the various layers of the binder has been assembled. As discussed above the attachment means are preferably arranged to correspond with punchings in the outer cover, whereby it is avoided that the attachment of the ring mechanism also attaches the outer cover to the panels.

The invention is further described in relation to the drawings: In Fig. 1 a partial view of the binder seen from the interior surface is shown. The binder is generally indicated as 1. The binder 1 is shown during production, after the outer cover 3 has been applied to the exterior surface of the panels 2 and folded around the edge of the panels 2 to be attached at the interior surface of the panels 2.

The part of the outer cover 3 being attached to the interior surface of the panels 2 depends on the size and form of the outer cover 3 in relation to the panels 2. When the panels comprise corners having an angle close to or equal to 90 ° it is preferred that the corresponding corners of the outer cover 3 are cut obliquely before folding to reduce the amount of material in the corners. Preferably the outer contour of the outer cover 3 is defined and cut before the outer cover 3 is attached to the panels 2.

In Fig. 2 a view corresponding to Fig. 1 is shown, including an inner cover 4 attached to the panels and the folded part of the outer cover 3. The borders of the outer cover 3 is shown by broken lines.

Fig. 3 shows the arrangement of the various layers of the binder, whereby the outer cover 3 is seen to cover the exterior surface of the panels 2 and being folded to cover a part of the interior surface of the panels 2 as well. Furthermore, the inner cover 4 is seen to cover the interior surface of the panels 2 as well as a part of the folded outer cover 3.