GB2376438A

GB2376438A - Method of stiffening a folded or hinged sheet

Info

Publication number: GB2376438A
Application number: GB0114708A
Authority: GB
Inventors: John Hanlon
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-06-15
Filing date: 2001-06-15
Publication date: 2002-12-18
Also published as: WO2002102599A3; WO2002102599A2; GB0114708D0; AU2002302821A1

Abstract

A folded substrate 35 e.g. a map or chart, has a stiffening treatment 40 such as aqueous coating, ink coating, other coating, spot lamination or varnish applied to it by spraying, laying as film or printing. The hinge 30 is formed by not applying the treatment, by applying a lesser (e.g. thinner) treatment or by applying a different treatment to a region of the base material. That region then forms a strip or band of untreated, less treated or differently treated base material that is more flexible than the treated.

Description

Hinged and hingeable sheet or strip materials This invention relates to hinged and hingeable sheet or strip materials, notably folded or foldable printed or pressed materials, and to articles made from such materials, such as information booklets, sheets and leaflets. The invention also relates to methods of making such materials and articles. Specific aspects of the invention relate to materials made from wood-based or synthetic substrates suitable for stationery and publishing uses. Such substrates will be referred to hereinafter in describing the invention and its benefits.

Printed or pressed materials can be used as a medium for communicating images and text, the former bearing largely two-dimensional matter (although some threedimensionality or texture is common in printed materials) and the latter bearing threedimensional matter. They can store and convey large amounts of information in many forms. For example, matter can be represented on the surface of a printed material as text, maps, charts, pictures, graphs, diagrams, numerals, sketches, music, electronic strips and tags, bar codes, holograms, codes, games and the like.

Examples of wood-based substrates that are suitable for printing or pressing include paper, coated paper, laminated paper, board and card. Examples of synthetic substrates that are suitable for printing or pressing include non-wovens, for example polythene, vinyl, polypropylene and other such materials like Polyart by Arjobex, Tyvek by Dupont, Teslin or Tupo (formerly Synteape). All are acknowledged as trade marks.

However, this list is not exhaustive; other sheet or strip materials that can have methods of printing or pressing applied to them are envisaged as being suitable for the purposes of the invention.

Depending upon the requirements of the finished product, substrates have to be suitable for use in various print and pressing processes including: application of printing inks and coatings; finishing processes such as lamination ; embossing; and foil-blocking. Use of synthetic substrates may require consideration in ink design in order to produce the required stiffness, binding and drying characteristics.

As the amount of information carried by a printed or pressed sheet or strip can be considerable, this may result in an article that is large and unwieldy. Consequently, it is common for the article to be reduced to a smaller size for ease of carriage and handling, most commonly by folding. Another benefit of reduced size is that it allows the user to digest the information being conveyed more readily. Thus, the user can concentrate only on the information being presented on an exposed surface portion of a folded article, and need not be distracted by the surrounding information exposed when the article is unfolded.

There is a limit to the number of times a sheet or strip of substrate can be folded before it becomes too unwieldy. For example a map can only be folded a few times to make it pocket-sized before it becomes too thick to fold any more. There is also a limit to how many times each fold, acting as a hinge, can be folded and unfolded before material fatigue failure might occur, for example frayed edges leading to tears in the material.

In principle, rigidity in the substrate is a preferred feature for resistance to bending, crumpling and general wear and tear in use of the article. The drawback is that the more rigid the substrate is, the harder it will be to fold. To the user, the relative ease of folding one substrate compared to another depends upon the relative rigidity of the substrates, if the gauge thickness of each material remains the same.

In the context of folds in a substrate, the line of a fold is referred to as a hinge, and the resistance of the hinge to open or close is referred to as hinge flexibility. It is known that hinges may be produced that possess different hinge flexibilities for opening and closing movements. In addition, it is known that hinges may be produced that have a built-in bias to remain in either an open or closed configuration. Leaving aside any treatments that may be applied to a substrate, hinge flexibility is an intrinsic property of the substrate material chosen.

It is desirable in many circumstances to increase the hinge flexibility of the substrate when in use. Put another way, the rigidity of the substrate is reduced in the region of the hinge. This can be achieved by producing the substrate so that before the first use, it is pre-folded, creased, perforated or clipped along the line of the hinge. Such methods of locally reducing the rigidity of the substrate material result in reduced effort required by

the user to fold or unfold the substrate. They can be applied to the substrate material before, during or after the printing or pressing of matter onto the substrate.

Other attempts at producing foldable, conveniently-sized printed articles include methods using a combination of outer films of laminating material encapsulating the inner substrate material preceded by the action of cutting strips from the inner substrate material. In this way, a plurality of discontinuous sheets or panels of substrate material can be encapsulated by laminating films, whereby the hinges are defined by the laminating films bridging the gaps between adjacent sheets or panels of substrate material. There are also methods of extruding and moulding plastics to produce plastic hinges specifically intended for ease of folding or unfolding. In general, there are various methods of stitching, welding and/or adhesion of composite materials together to produce the overall effect of a hinge.

For example, GB 2339721 A to Lipscombe describes a discontinuous substrate in which the substrate is in separate sheets, and an outer continuous material wrapping or encapsulating the substrate. This encapsulating material is thicker than the substrate being encapsulated. The production process involves various additional cutting, arranging and encapsulating stages over and above the relatively simple printing process. In addition, this prior art is restricted to being used for single strips of card.

EP 0997271 A2 to Gardiner describes a method of laminating a foldable strip of spaced opaque panels, comprising die-cutting an array of parallel transverse slots in a strip of paper to define the panels and then laminating the strip. The strip is wider, and the slots are longer, than the desired width of the article so that after die-cutting and laminating, there is a further cutting process in which the side portions of the laminated strip are cut away to separate the panels and to define the desired width of the article. Gardiner's method effectively controls alignment of the panels but requires these various successive manufacturing steps on different machines.

GB 2296217 A to Hockaday teaches a hinge produced by moulding or welding plastics material. The result is a hinge biased towards its closed position when not held in the open position.

GB 1009441 to Foley discloses hinges defined by a variation in cross sectional thickness of a separate discontinuous strip of moulded base polypropylene material, and the composite addition of a continuous outer cover and a discontinuous inner material of varying cross sectional thickness. This produces a book cover and spine that hinges open to a limited 15 degree extent and reverts to the closed position when released.

WO 9605068 Al to Gunn describes two separate plastic members that are moulded and hinged together by either using a single continuous base material with decreasing cross sectional thickness to give more flexibility and thus a hinge, or by encapsulating two separate pieces together with two outer layers of film material.

US 4632428 to Brown considers a moulded plastic material with a reduction in crosssectional thickness to increase flexibility and thus provide a hinge in one direction.

Common to all these approaches are other steps in the production process, separate from the actions of printing or pressing of matter onto the substrate, in order to produce hinges. Inevitably these prior art examples increase the cost and complexity of producing the finished product.

For example, encapsulation requires that the material to be encapsulated is accurately aligned prior to encapsulation, or the finished product will not appear properly centred and oriented between the laminated sheets. Time has to be spent to ensure that alignment is achieved, or further finishing steps must be carried out to trim off the uneven excess laminate from the edges around the substrate.

In short, each of the known methods involve at least one step that would lead to a substantial increase in time and cost of the finished product, in what is traditionally a market offering a low profit margin per unit.

What is required, therefore, is a foldable material suitable for printing or pressing which does not require actions in its manufacture that are significantly different or more expensive compared to the printing or pressing actions themselves.

Against this background, the present invention resides in a foldable material carrying or suitable for carrying printed or pressed matter, the material comprising an unbroken flexible substrate having a stiffening treatment applied thereto or performed thereon, the stiffening treatment creating at least one relatively stiff region of the material adjoined by at least one relatively flexible region of the material having a lesser, a different or no stiffening treatment applied to or performed on the substrate, thereby defining a region at which the material can be folded.

The invention also resides in a method of producing a foldable material carrying or suitable for carrying printed or pressed matter, comprising applying or performing a stiffening treatment to or upon an unbroken flexible substrate, the stiffening treatment being varied in different regions of the substrate to create at least one relatively stiff region of the material adjoined by at least one relatively flexible region of the material having a lesser, a different or no stiffening treatment applied to or performed on the substrate, thereby defining a region at which the material can be folded.

Preferably, the stiffening treatment creates relatively stiff regions of the material separated by at least one relatively flexible region of the material having a lesser or no stiffening treatment applied to or performed on the substrate, thereby defining a plurality of relatively stiff panels, adjacent ones of which are separated by a relatively flexible band at which the material can be folded. The band is preferably straight for that purpose, although a plurality of bands may intersect or otherwise adjoin at an angle.

Whilst the flexibility of the flexible band may be enough in itself to facilitate folding, it is also possible for the band to be further adapted to define a hinge line. Such adaptation may involve locally increasing the flexibility of the material by, for example, reducing the plan area or the thickness of the material by scoring, notching, perforating, creasing or pre-folding the material along the hinge line. It is also possible for such adaptations to be employed in combination with each other.

Thus, the invention contemplates a variable, localised, intermittent or discontinuous stiffening treatment across the substrate. The discontinuity may be an interruption or break in the stiffening treatment: of course, where no stiffening treatment is applied to or performed on the substrate, the material constituting the relatively flexible region or

band is the substrate itself. However, it is possible for all of the substrate to be treated but for some parts of the substrate to receive more treatment than others.

The invention also resides in a material made by the method of the invention, and in a folded or foldable article made from the material of the invention or by the method of the invention.

Thus, the invention involves the production of a substrate with non-homogenous rigidity suitable for folding along a hinge line, the hinge line co-locating with a discontinuity in the rigidity of the substrate formed by the boundary of a physical property of the substrate.

One benefit of the invention is that substrates incorporating this hinge will require less dexterity to fold and unfold depending on the mix of materials and their dimensions. When flexible material such as paper or synthetic paper is folded, it usually requires two hands to unfold it or to hold it open or to fold it back up again. Such folds are usually made by hand or as part of the finishing element of the production process.

It is a preferred feature that use of selected materials, weights and dimensions may enable folding and unfolding to be achieved by a self-weighting mechanism requiring the use of just one hand to operate. Being able to use only one hand is an improvement to the traditional way of having to use two hands to fold and unfold paper and other such products. Indeed, the article of the invention can fall open largely under its own weight when held in the appropriate orientation. By virtue of its weight and stiffness, the unfolded article can stay open and lay open on a flat surface until it is picked up again, whereupon it can easily be folded back into a closed configuration. Similarly, folding or closing the article can take advantage of the article's own weight when it is held in the appropriate orientation. The invention is therefore particularly beneficial when used with large sheets such as maps or charts.

A broad objective of the invention is the production of a foldable material and article that looks, feels and handles better than other materials and articles for the same purpose. These advantages stem in part from the weighting of the article, the action of the hinges and the differential between the relatively stiff panels and the relatively

flexible hinges. The articles of the invention will provide commercial and functional benefits in a wide range of uses, in particular promotional, travel, scientific, sports, technical, educational and general information presentation.

A further benefit of the invention is that it permits a greater number of folds per unit unfolded plan area than previously possible. This is partially because the bands defining the hinges may be thinner than the treated substrate. It is also because the flexibility of the bands need not be compromised by the desirable stiffness and weight of the panels. Thus, the article of the invention can be predominantly stiff and weighty, yet flexible enough to be folded and easily opened, held open and closed.

A related benefit of the above invention is that the hinge will withstand numerous folding and unfolding operations. In particular, the potentially reduced cross-sectional thickness of the substrate material at the band reduces lateral strain in the substrate material during folding or unfolding. Consequently, such a hinge will be less susceptible to fatigue failure through fraying or tearing.

Although the invention may be used with any of the substrates mentioned herein, it is preferable that a synthetic paper is used to provide a product that is durable, water resistant, temperature resistant, tear resistant, grease and oil resistant.

It is preferred that the differential rigidity of the substrate is effected by a treatment applied to the substrate. More specifically, it is preferred that the rigidity of the substrate can be varied by applying at least one coating to the surface of the substrate. These coatings include those that can be applied as a print process, which generally fall into three types: Varnish :-Preferably colourless ink that may consist of a vehicle but little or no pigment. Normally binds to the substrate through a variable mix of the three main mechanisms of chemical action, absorption and evaporation.

Aqueous coating :-Preferred aqueous coatings envisaged consist of between 40% and 50% solids and 60% and 50% water. They are usually applied through a dedicated in-line coating system but occasionally through a dampening unit.

UV varnish/coating :-Preferably this type of coating can be applied'in-line'via an ultra-violet coating system or'off-line'using a special unit for ultra-violet varnish. This has the advantage that ordinary inks can be used to print to the substrate with a specially formulated UV ink/varnish/coating being used to stiffen selected areas of substrate and giving a differential rigidity, leaving untreated or differently-treated areas of the substrate where required to form hinges.

Other types of seal varnishes and coatings may be used to stiffen selected regions of a substrate, particularly with matt and satin-coated substrates, and are normally used in conjunction with hot air or infra-red drying units. Examples of these are: varnish-based

coatings, which have a vamish/resin base allowing quick drying by oxidation giving a sealed result ; glycol-based coatings ; and water/aqueous-based coatings.

- ('Off-line'print-finishing processes such as laminating, foil-blocking, embossing (pressing) and de-bossing might be utilised to effect differential rigidity and hence effect the hinge of the invention. In addition, or in the alternative, other processes such as creasing, cutting, punching, cording and stringing, perforating, drilling, stitching, / scoring, folding and trimming may also be used to further effect or vary differential rigidity at the hinge.

The invention also contemplates that adhesives for ink and varnishes can be applied to vary the stiffness of the substrate. These adhesives are generally in the form of a binder material dissolved in a vehicle. The mechanisms of adhesion, absorption, oxidation and polymerisation to the substrate material can also be controlled, for example by the constituents in the adhesive, by the type of substrate used and also by the methods of application and drying.

In another embodiment of the invention, the substrate may be stiffened by saturation.

This process involves treatment of the substrate by distributing the saturating material into and through (and preferably completely throughout) the substrate material, as opposed to a coating which is more akin to laying on the surface of the substrate. Saturation is used to increase strength and durability and it can be used in selected areas

to effect differential rigidity across the substrate and hence produce a hinge in the substrate. Suitable saturating materials include thermosetting resins like phenolformaldehyde or melamine-formaldehyde. Thermoplastic resins may also be used in a similar way.

(Optionally, one or more lamination sheets or films may be used to vary the rigidity of I (regions of the substrate by varying the amount, configuration or nature of the lamination sheets or films, or by varying the composition and application of the adhesive material t used to secure the lamination sheets or films.

" In a further development of the invention, the rigidity of the substrate may be varied by a treatment applied to one or both sides of the substrate either'on machine'or'off machine'. Suitable treatments may also be used to vary the brightness, gloss, smoothness, 'caliper' (thickness) and uniformity of the substrate. The material components within the coating treatment (for example pigments, binders or additives, either natural or synthetic) may also be varied to control rigidity of the substrate.

It is also possible to vary the drying process for the coating treatment to control the

rigidity of the selected areas of treated substrate.

Another optional tenture is me use or embossing rollers, lurmeu irum a pair oi male ana female rollers, to create differential rigidities or stiffness across selected areas of the substrate. These rollers may be similar to rollers used to give decorative finishes to substrates by impression or depression. The differential rigidities arising from use of such a system occur by varying the thickness or cross-sectional shape of the compressed fibrous structure of a typical substrate.

In a further variant of the invention, foil blocking may be used to effect the required differential rigidity. Foil blocking uses the application of heat and/or pressure to bond various layers of metallic laminated sheets via a base carrier film to the substrate material, and is usually used to produce striking metallic finishes for aesthetic appeal. Due to the effect of the substrate, the adhering techniques and the different rigidity and number of the metal laminations themselves, this process could also be utilised to impart differential rigidity and hence create a hinge in accordance with this invention.

In a further embodiment of the invention, differential rigidity of the substrate may be imparted into the substrate at the time of manufacture of the substrate, resulting in the substrate coming out at the'dry'end of the manufacturing process ready for use in articles with differential rigidity. The processes that may be utilised during the manufacturing process of the substrate to impart differential rigidity include: Moving wire :-This is an endless moving belt of fine mesh made from wire, nylon or synthetic material that moves the wet substrate forward and agitates it laterally at the same time in order to reduce the moisture content by draining water off. The substrate is typically I % solid and 99% water prior to this stage in the process. In the same way as this process can cause a'wire mark'on the substrate, the wire could be configured to produce selected areas of varied caliper (thickness) or moisture content and hence vary the rigidity of the substrate at selected areas.

Dandy roll/watermark and the like :- At this stage of the manufacturing process, the substrate is over 90% water and less than 10% solid. The dandy roll is a cylinder of wire gauze that compresses the fibres and smoothens the top surface of the substrate. This follows the process of passing the substrate over suction boxes and/or foils to further reduce the moisture content. The dandy roll is used to incorporate watermarks into the substrate by impressing an image into the top of the substrate and the water content is typically reduced to 60% by the time the substrate comes out from the dandy roll system. In accordance with this invention, the dandy roll could be utilised to impress selected areas of the substrate to produce differential rigidity between those areas impressed and those areas either less impressed or not impressed at all.

Suction couch :- One of the steps in the manufacturing process of the substrate is for the substrate to be rolled via a'couch'roll using suction to reduce moisture.

Then, heavy metal press rolls remove more water and consolidate the sheet. The couch roll may be configured to incorporate selected areas of reduced water content or thickness in order to produce the required differential rigidity in the substrate, in accordance with this invention.

Heavy press rolls :-Heavy press rolls may be configured to vary the water content and/or thickness of the substrate at selected areas in order to effect differential rigidity in accordance with this invention.

Drying cylinders :-During the manufacturing process of the substrate, the unfinished substrate may go through a series of steam-heated drying cylinders. These may be configured to achieve the differential rigidity in accordance with this invention, by varying water content and/or thickness.

Smoothing rolls :- Smoothing rolls may be used to effect surface finishes of the substrate. These smoothing rolls could again can be configured and utilised to produce differential rigidity, by varying water content and/or thickness.

Calendering :- Calendering and super-calendering processes generally employ a system of rolls at the dry end of the manufacturing process that further compress and smooth the sheet of substrate to the required specification prior to any subsequent conversion processes. Again, calendering and super-calendering could be utilised to vary the thickness, surface finish, moisture content and absorption properties in selected areas in order to effect differential rigidity across the substrate.

Cooling rolls :- In the manufacturing process of the substrate, after calendering, the substrate passes through a series of cooling rolls to reduce its temperature.

Again, parameters such as thickness, surface finish, moisture content and absorption properties can be varied by controlled use of these rolls.

Furnishing :-Furnishing (including loading, filling or sizing) involves the addition of substances to the substrate in order to enable the fibres within the substrate to bond better or to exhibit some other characteristic at a different level, and may be used to vary the rigidity of the substrate in desirable areas.

Furnishing processes comprise, but are not limited to,'loading'with'filler' material (substances such as china clay and calcium carbonate) to fill the gaps between the fibres of the substrate so as to improve qualities such as smoothness

or opacity. Another furnishing process is'sizing'whereby synthetic or resinous materials are added to bind the fibres of the substrate to retard the penetration of water and to prevent ink or varnish spreading into the paper. This process could similarly be used in accordance with this invention or in conjunction with other processes, for example to increase adhesion and reduce absorption.

Thus, it will be evident that the stiffening treatment contemplated by the invention can be applied to or performed on the substrate when the substrate is being produced, or after the substrate has been produced.

Further beneficial but optional features are set forth in the subsidiary claims appended to this description and in the specific description that now follows. Accordingly, in order that this invention can be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a perspective view of a first embodiment of the invention; Figure 2 is a longitudinal sectional view of the first embodiment showing part of an unfolded article; Figure 3 is a longitudinal sectional view corresponding to Figure 2 but showing part of a partially folded article ; Figure 4 is a longitudinal sectional view corresponding to Figures 2 and 3 but showing part of a fully folded article; Figure 5 is a plan view of the whole article of the first embodiment shown in Figures 1 to 4 in the unfolded, open position of Figure 2; Figure 6 is a plan view of a second embodiment of the invention; Figure 7 is a plan view of a third embodiment of the invention;

Figure 8 is a perspective view of a part of the article shown in Figures 1 to 5 or 7 ; Figure 9 is a longitudinal sectional view of a fourth embodiment of the invention ; Figure 10 is a longitudinal sectional view of a fifth embodiment of the invention; Figure 11 is a longitudinal sectional view of a sixth embodiment of the invention ; Figure 12 is a longitudinal sectional view of a seventh embodiment of the invention; Figure 13 is a longitudinal sectional view of an eighth embodiment of the invention ;

..

Figure 14 is a longitudinal sectional view of a ninth embodiment of the invention; Figure 15 is a longitudinal sectional view of a tenth embodiment of the invention; Figure 16 is a longitudinal sectional view of an eleventh embodiment of the invention; Figures 17 and 18 are plan views of foldable articles in twelfth and thirteenth embodiments of the invention; Figures 19,20 and 21 are longitudinal sectional views of a part of an article in fourteenth, fifteenth and sixteenth embodiments of the invention ; Figure 22 is a plan view of a part of a foldable article in a seventeenth embodiment of the invention ;

Figure 23 is a plan view of a foldable article in an eighteenth embodiment of the invention; Figure 24 is a longitudinal sectional view of a nineteenth embodiment of the invention; Figure 25 is a longitudinal sectional view of a twentieth embodiment of the invention; Figure 26 is a partial longitudinal sectional view of the interface between a treatment and a substrate; Figure 27 is a cross-sectional view of the treated substrate of Figure 26, in which the treatment is completely absorbed by the substrate; Figure 28 is a cross-sectional view of the treated substrate of Figure 26, in which the treatment is partially absorbed by the substrate; Figure 29 is a longitudinal sectional view of a twenty-first embodiment of the invention; Figure 30 is a longitudinal sectional view of a twenty-second embodiment of the invention; Figure 31 is a plan view of a twenty-third embodiment of the invention; Figure 32 is a plan view of a twenty-fourth embodiment of the invention; Figure 33 is a longitudinal sectional view of a twenty-fifth embodiment of the invention; and Figure 34 is a longitudinal sectional view of a twenty-sixth embodiment of the invention.

Referring firstly to Figures 1 to 5 of the drawings, Figure 1 is a perspective view of a first embodiment of the invention, being a part of a foldable strip-like article having relatively stiff oblong panels separated by a straight hinge band 30 created by differential rigidity of a continuous, unbroken but intermittently-treated substrate 35 of constant cross-section. Specifically, the panels are stiffened by intermittent, localised patches of treatment 40 opposed to each other about the thickness of the substrate 35 and the hinge band 30 is relatively flexible by virtue of the lack of a treatment 40 at that region. That region may be thought of as a gap or discontinuity in the treatment 40.

In the first embodiment, the treatment 40 is a single-layer, single-material absorption treatment or the like applied to the substrate material. Other treatments are possible such as coatings, varnish, ink and various adhered materials, as has been mentioned and as the succeeding embodiments will exemplify,.

Figures 2,3 and 4 are longitudinal sectional views of the first embodiment when the hinge band 30 is in an unfolded open and flat position, when the hinge band 30 is bent

through 90 into a partially folded position, and when the hinge band 30 is bent through 180 into a fully folded position respectively. In that fully folded position, successive panels defined by the stiffening treatment 40 overlie each other, concertina-fashion, in an optimally compact configuration.

Figure 5 is a plan view of the whole article of the first embodiment shown in Figures 1 to 4 in the unfolded, open position of Figure 2, being a folding card article having an alternating sequence of parallel hinge bands and panels so that the article folds in only one direction or plane. Each panel of the article can be pre-printed or pressed with matter such as text, graphics or a relief pattern, or can be printed or pressed with such matter after production.

In the description of other embodiments that follows, corresponding reference numerals will be used for like parts such as the hinge bands 30, the substrate 35 and the treatment patches 40.

Figure 6 is a plan view of a second embodiment of the invention, being another folding card article akin to the first embodiment. However, in this case, the treatment patches 40 are disposed in a matrix and the intermediate hinge bands 35 intersect in mutually orthogonal rectilinear arrays, so that article folds in two mutually orthogonal directions or planes.

Figure 7 is a plan view of a third embodiment of the invention, being another folding card article akin to the first embodiment of Figures 1 to 5 but of different shape and proportions. This shows how the shape of the article and its constituent panels and hinge bands 30 can be varied.

Figure 8 is a perspective view of a part of the article shown in Figures 1 to 5 or 7, in which two successive hinge bands 30 are in partially folded positions during folding or unfolding of the article.

Figures 9 to 16 are a succession of longitudinal sectional views of various embodiments, showing how an untreated or less-treated hinge band 30 can be created between treated, more-treated or at least differently-treated regions of a substrate 35. These examples all have various configurations of treatment 40 applied to a uniform substrate 35, and some have other treatments as will become apparent. They show how the principle of the invention can be realised with varying geometrical compositions of substrate and one or more finishing layers.

Turning firstly to Figure 9, a fourth embodiment of the invention has the substrate 35 treated continuously on one side by a coating 40 and discontinuously on the other side, leaving a gap in the treatment 40 that defines the hinge band 30.

The fifth embodiment illustrated in Figure 10 has the substrate 35 partially treated by a treatment 40 on one side and similarly partially treated on the other side but in an offset manner such that no portion of the substrate 35 is treated on both sides, and also leaving an untreated gap that defines the hinge band 30.

The sixth embodiment of Figure 11 is akin to the fifth embodiment of Figure 10, but in this case one portion of the substrate 35 is treated by a treatment 40 on both sides and

another portion of the substrate 35 on the opposite side of the hinge band 30 is treated on only one side. This shows that the relatively stiff regions on opposite sides of the hinge band 30 need not themselves be of equal stiffness to each other.

Figure 12 shows a seventh embodiment akin to the sixth embodiment of Figure 11, but in which one portion of substrate 35 is treated on both sides and the remainder of the substrate 35 has no treatment 40. The eighth embodiment of Figure 13 is simpler still in that one portion of the substrate 35 is treated on only one side and the remainder of the substrate 35 has no treatment 40 on either side.

As mentioned above, it is possible to have more than one treatment. This principle is illustrated in Figure 14 which shows a ninth embodiment corresponding to the fourth embodiment of Figure 9, but having an additional continuous treatment 50 on the side of the substrate 35 that is already continuously treated by the treatment 40.

Figures 15 and 16 also show an additional treatment 50, but in these cases applied discontinuously as will now be explained.

The tenth embodiment shown in Figure 15 corresponds to the first embodiment of Figures 1 to 5, but has an additional treatment 50 completely covering the portions of the substrate 35 treated by the treatment 40. An untreated portion of the substrate 35 remains to define a hinge band 30. As an alternative, it would also be possible for the additional treatment 50 to be continuous, covering both the treatment 40 and the substrate 35 in the region of the hinge band 30. This reaffirms that the substrate 35 need not be wholly untreated in the region of the hinge band 30.

The eleventh embodiment shown in Figure 16 broadly corresponds to the tenth embodiment of Figure 15, but in this case the additional treatment 50 only partially covers the underlying treatment 40, leaving a portion of the underlying treatment 40 exposed adjacent the hinge band 30.

Figures 17 and 18 are plan views of twelfth and thirteenth embodiments of the invention, each showing foldable articles akin to the first and third embodiments described above. In these further embodiments, cut-outs or notches 55 in the edges of

the strip are aligned with the hinge bands 30 to reduce the plan area of each hinge band along a hinge line aligned with the hinge band 30. This further increases the flexibility of the hinge bands 30 in relation to the panels defined by the oblong patches of treatment 40. The cut-outs or notches 55 can, for example, be die-cut.

There are other ways of increasing hinge flexibility or reducing hinge stiffness. For example, Figures 19, 20 and 21 are longitudinal sectional views of a part of an article in fourteenth, fifteenth and sixteenth embodiments of the invention. They are all akin to the first embodiment of Figures 1 to 5 in terms of the disposition of the treatment 40 but their hinge bands 30 include various hinge adaptations 60 such as creasing, folding and scoring that reduce the cross-section of the hinge band 30 or otherwise increase its flexibility along a hinge line. Specifically, the hinge adaptation 60 in Figure 19 is a bidirectional, symmetrical crease, fold or score line along the hinge band 30 that reduces the cross-section of the hinge band 30 and increases its flexibility to ease bending in two directions about the hinge line. Conversely, the hinge adaptation 60 in Figure 20 is a uni-directional, asymmetrical crease or fold along the hinge band 30 that increases the flexibility of the hinge band 30 to ease bending in one direction about the hinge line but to resist bending in another direction about that line. The hinge adaptation 60 in Figure 20 may also bias a foldable article into a folded or shut state.

Similarly, the hinge adaptation 60 in Figure 21 is uni-directional and asymmetrical in the sense that it increases the flexibility of the hinge band 30 to ease bending in one direction about the hinge line while offering greater resistance to bending in another direction about that line. However, in this instance, the hinge adaptation 60 is a parallel pair of scored lines on one side of the substrate 35, along the hinge band 30.

Figure 22 is a plan view of a part of a foldable article in a seventeenth embodiment akin to the twelfth and thirteenth embodiments shown in Figures 17 and 18 in that cut-outs or notches 55 reduce the plan area of each hinge band 30 along a hinge line aligned with the hinge band 30. In this case, however, perforations 70 further reduce the plan area of each hinge band 30 to increase further the flexibility of the hinge bands 30 and further to define the hinge line. The combination of cut-outs or notches 55 with perforations 70 exemplifies how different hinge adaptations can be combined beneficially.

A further variant is shown in Figure 23, which is a plan view of a foldable article in an eighteenth embodiment of the invention. That embodiment is akin to the twelfth and thirteenth embodiments in that cut-outs or notches 55 in the edges of the strip reduce the plan area of the hinge band 30 along a hinge line, but in this case the cut-outs or notches 55 define rounded comers to the relatively stiff panels of the article defined by patches of treatment 40. The panels therefore take on the appearance of credit cards and if appropriately sized, can enable the folded article to fit into a credit card holder such as a wallet.

Moving on now to Figures 24 and 25, these are longitudinal sectional views that follow on from the sequence of Figures 9 to 16 showing how the principle of the invention can be realised with varying geometrical compositions of substrate and one or more finishing layers.

Referring specifically to Figure 24, it has already been mentioned that a hinge band 30 need not be a wholly untreated region of substrate 35 if it is to function in the manner contemplated by the invention. Figure 24 reaffirms this by showing the substrate 35 continuously treated on both sides with a treatment 40 and an additional discontinuous treatment 50 applied to each of the continuously-treated sides of the substrate 35. In this case, the discontinuities in the outer treatment 50 align to define a hinge band 30, although it would also be possible to define a hinge band 30 with only one discontinuity on one outer treatment 50 and no corresponding discontinuity on the other outer treatment 50, which could therefore be continuous like the underlying inner treatment 40.

The twentieth embodiment shown in Figure 25 has a discontinuous treatment 40 applied to each side of the substrate 35, the discontinuities aligning to define a hinge band 30 as in many of the previous embodiments. In this embodiment, however, the treatment 40 is of variable thickness, being one way in which the self-weighting of the article can be controlled. The change in thickness of the treatment 40 is shown by way of example as an increase in thickness moving away from the hinge band 30.

Figure 26 is a partial longitudinal sectional view of the interface between a treatment and a substrate 35, showing how a treatment in the form of a coating, varnish, ink or

adhered material 40 can be absorbed into the treated substrate 35, partially (75), completely (80) or barely at all (85). Figures 27 and 28 are cross-sectional views of the treated substrate 35 of Figure 26, in which the treatment 40 is completely absorbed by the substrate 35 (Figure 27) and partially absorbed by the substrate 35 (Figure 28) The twenty-first and twenty-second embodiments of Figures 29 and 30 are shown in longitudinal sectional view like Figures 9 to 16, 24 and 25, but differ from the preceding embodiments in that the substrate (in this case comprising the reference numerals 90 and 95) is simply a plurality of laminated layers, outer discontinuous laminated layers 90 forming both sides of the substrate. The substrate may be of a composite material comprising laminated layers of materials fused together during the substrate manufacturing process and sandwiched between the outer laminated layers 90. Thus, the substrate material itself can be manufactured using layers of materials laminated together to form a composite substrate material. This process may, for example, take place during a paper-making process before a paper-based substrate is even sent to a printing factory.

Figure 29 shows how the outer laminated layers 90 can both be discontinuous, with the discontinuities aligning to define a hinge band 30 of the composite substrate in much the same manner as the treatments 40 of the first embodiment shown in Figures 1 to 5.

Figure 30 is a longitudinal sectional view of a twenty-second embodiment in which, like the twenty-first embodiment of Figure 29, the composite substrate comprises a laminated layer having outer laminated layers 90 applied to both sides, but in which the outer laminated layers 90 are continuous and the inner laminated layer of the composite substrate has a discontinuity 100 (being a region of different treatment, different material, or less material) defining the hinge band 30.

Figures 31 and 32 show how a treatment such as a coating, varnish, ink or adhered material 40 may be applied to variously-shaped regions of a substrate 35, such as strips around an oblong frame, depending upon the folding, hinging and self-weight characteristics required of the article. The twenty-third embodiment of Figure 31, for example, is a plan view of a foldable article, unfolded into a single plane, in which each panel of the article is defined by a frame 40 of relatively stiff coated or otherwise treated

substrate around a relatively flexible (being less treated, differently treated or untreated) portion of substrate 35. As before, the treatment leaves a relatively flexible hinge band 30 between successive frames.

The twenty-fourth embodiment of Figure 32 develops this idea in that the frames of the panels are of various geometric shapes and treatment areas. In particular, it will be noted that the outer panels of the article at the end of the strip are subject to a heavier treatment in the form of a larger area of treatment 40. In this way, the greater selfweight of those outer panels will help to close and open the article. Similar selfweighting effects may be obtained by increasing the thickness of the treatment 40 of the outer panels relative to the inner panels, or by changing the composition of the treatment or other treatment applied to the outer panels to make them heavier and/or stiffer than the inner panels.

Figure 33 is a longitudinal sectional view of a twenty-fifth embodiment in which the substrate is treated by being embossed, debossed or pressed to define hinge bands 30 between panels. Whilst the whole substrate may be treated in this way or only parts of it, the treatment is such that different degrees of treatment are applied to different regions of the substrate as appropriate. Specifically, some regions 115 of the substrate are more compressed than other regions 120 of the substrate: regions 120 therefore have a greater thickness 105 than the thickness 110 of regions 115.

The effect of this differential compression on the substrate in terms of its flexibility or stiffness depends upon the nature of the substrate. Some substrates will stiffen the more they are compressed and hence the thinner they get; for example, the fibres of a fibrous substrate may compact and entwine, stiffening the substrate to an extent that overcomes its reduction in thickness. However, other substrates that do not undergo such a change of internal structure during compression will simply become more flexible the more they are compressed and hence reduced in thickness. So, the relatively thin regions 115 may be more flexible or less flexible than the relatively thick regions 120, depending upon the substrate and its response to the embossing, debossing or pressing treatment employed.

Figure 33 indicates that the hinge bands 30 are defined by the relatively thin regions 115 but, in other substrates that stiffen with greater compression, the hinge bands 30 could instead be defined by the relatively thick regions 120 which would then be more flexible that the relatively thin regions 115.

The embossing, debossing or pressing process is also apt to be used with foil-blocking, which can itself influence the local stiffness of the treated substrate.

Turning finally to Figure 34, this is a longitudinal sectional view of a twenty-sixth embodiment that is akin to Figure 24 in that the substrate 35 is treated throughout but is differently-treated in a hinge region. In this instance, the different treatment is achieved by varying the composition of the treatment coating 40 at the hinge region 125, to define a hinge band 30 corresponding to the hinge region 125.

In summary, therefore, the principle of the invention is to use a flexible base material or substrate that has a stiffening treatment performed on it or applied to it such as an aqueous coating, spot lamination or varnish by spraying, laying as film or printing. The stiffening treatment may, for example, provide a stiffer composite material. The hinge is formed by not applying the treatment, by applying a lesser (e. g. thinner) treatment or by applying a different treatment to a region of the base material. That region then forms a strip or band of untreated, less treated or differently-treated base material that is more flexible than the treated, more treated or differently-treated base material in other regions. The more flexible region is therefore apt to be used as a hinge.

The differential in stiffness or flexibility between the different regions of the base material can be achieved in various ways. For example, the base material and/or the material used in stiffening treatment can be varied in their material composition or other physical characteristics. The base material and/or the material used in stiffening treatment can be varied in their dimensions and/or in the numbers of layers. A formation such as a crease, a fold, a perforation, and/or any other finishing process such as scoring can be applied to or formed in the base material to give the required differential in stiffness or flexibility.

The invention can be put into practice by the use of existing printing and finishing processes, hence minimising set-up and changeover costs in terms of investment in new processes and machinery. The base material can be fed through the printing process continuously in one sheet or strip. No breaks or cuts are needed in the base material, and no moulding or extrusion methods are required. Indeed, the whole or substantially all of the treatment process can be done at the same time as printing or pressing matter onto the base material, and by the same machines.

Numerous variations are possible within the inventive concept. For example, the substrate can be paper, synthetic material including synthetic paper, plastics material and/or cloth or other textile.

Many other variations are possible, and the present invention may be embodied in other specific forms without departing from its essential attributes. Accordingly, reference should be made to the appended claims and other conceptual statements herein rather than to the foregoing specific description as indicating the scope of the invention.

Claims

CLAIMS 1. A foldable material carrying or suitable for carrying printed or pressed matter, the material comprising an unbroken flexible substrate having a stiffening treatment applied thereto or performed thereon, the stiffening treatment creating at least one relatively stiff region of the material adjoined by at least one relatively flexible region of the material having a lesser, a different or no stiffening treatment applied to or performed on the substrate, thereby defining a region at which the material can be folded.
2. The material of Claim 1 and comprising a plurality of relatively stiff panels having a stiffening treatment applied thereto or performed thereon, adjacent ones of which are separated by a relatively flexible hinge band at which the material can be folded.
3. The material of Claim 2, wherein the hinge band is straight.
4. The material of Claim 2 or Claim 3, wherein a plurality of hinge bands defined between a plurality of panels are in parallel.
5. The material of any of Claims 2 to 4, wherein a plurality of hinge bands are in intersecting or otherwise adjoining arrays.
6. The material of any of Claims 2 to 5, wherein the hinge band is associated with a hinge adaptation locally increasing the flexibility of the substrate.
7. The material of Claim 6, wherein the hinge adaptation reduces the plan area of the substrate by notching or perforating.
8. The material of Claim 6 or Claim 7, wherein the hinge adaptation reduces the thickness of the substrate by scoring, creasing or pre-folding.
9. The material of any preceding Claim, wherein the stiffening treatment is applied or performed across the substrate in a localised, broken, patchy or intermittent manner.

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10. The material of any of Claims 1 to 8, wherein the stiffening treatment is applied or performed across the substrate in an unbroken but variable or discontinuous manner.
11. The material of any preceding Claim, wherein the stiffening treatment is extrinsic to the substrate.
12. The material of Claim 11, wherein the stiffening treatment is at least one coating, varnish, ink or lamination applied to the substrate to make a composite material.
13. The material of Claim 12, wherein the coating, varnish, ink or lamination is of varying thickness across the substrate.
14. The material of any of Claims 11 to 13, wherein the coating, varnish, ink or lamination frames at least one relatively stiff panel of the material.
15. The material of any of Claims 11 to 14, wherein the coating, varnish, ink or lamination is applied to a plurality of relatively stiff panels of the material and wherein the area, shape, weight, composition and/or thickness of the coating or lamination differs from one panel to another.
16. The material of any of Claims 11 to 15, wherein the coating, varnish, ink or lamination is unbroken but varies in thickness or composition across the substrate.
17. The material of any preceding Claim, wherein the stiffening treatment alters the intrinsic composition or structure of the substrate.
18. The material of any preceding Claim, wherein the stiffening treatment involves pressing the substrate.
19. A method of producing a foldable material carrying or suitable for carrying printed or pressed matter, comprising applying or performing a stiffening treatment to or upon an unbroken flexible substrate, the stiffening treatment being varied in different regions of the substrate to create at least one relatively stiff region of the material adjoined by at least one relatively flexible region of the material having a lesser, a different or no

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stiffening treatment applied to or performed on the substrate, thereby defining a region at which the material can be folded.
20. The method of Claim 19, wherein the stiffening treatment creates relatively stiff regions of the material separated by at least one relatively flexible region of the material having a lesser, a different or no stiffening treatment applied to or performed on the substrate.
21. The method of Claim 19 or Claim 20, further comprising performing or applying a hinge adaptation to the relatively flexible region of the material, further to increase the flexibility of the material at that location.
22. A foldable material made by the method of any of Claims 19 to 21.
23. A folded or foldable article made from the material of any of Claims 1 to 18 or 22, or by the method of any of Claims 19 to 21.
24. A folded or foldable article or material, substantially as hereinbefore described with reference to or as illustrated in any of the accompanying drawings.
25. A method of producing a foldable material, substantially as hereinbefore described.