GB2378154A

GB2378154A - Forming weak cohesive bonds in sealing a document so that it might be opened by peeling without tearing

Info

Publication number: GB2378154A
Application number: GB0119044A
Authority: GB
Inventors: Raymond John George
Original assignee: PFE International Ltd
Current assignee: PFE International Ltd
Priority date: 2001-08-03
Filing date: 2001-08-03
Publication date: 2003-02-05
Anticipated expiration: 2021-08-03
Also published as: GB2378154B; GB0119044D0

Abstract

An apparatus suitable for pressure sealing documents 1 having a paper substrate, at least one fold line 3 and a plurality of cohesive deposits 2, comprises means, such as rollers 5,6, of applying a pressure to at least one edge of the folded document 1, which is either less than 100 lbs per linear inch / light enough such that the cohesive bonds formed are weaker than the shear strength of the paper. In such a way, an envelope formed from the folded document 1 might be opened without tearing the paper substrate. Also disclosed is an associated method comprising folding the document 1 so the cohesive deposits superimpose, and applying a suitable pressure as described above. The document 1 may be Z-folded, suitable areas of cohesive 2 on the front (fig. 1a) and back (2,fig. 1b) allowing such a folding. The folding device may be used as part of a process which may further involve a blank document supply, printing, folding, insertion, sealing and stacking (12,13,14,17,15,16, fig.3). A second pressure application, of greater than 100 lbs per linear inch, such as up to 220 lbs, may be applied by a second pressure application means such as a second set of rollers (12a, 13a, fig.4).

Description

Pressure sealing apparatus and method The present invention is in the field of pressure sealing apparatus used to bond cohesive deposits on documents such as business forms.

A number of different types of pre-printed business forms are available which have deposits of adhesive or cohesive which are activated by pressure to produce a secure, tamper proof document. These are used for example to deliver salary information to employees and pin numbers to credit card owners. The main benefit of such forms is that they can carry public information externally and conceal confidential information internally when the form is simplex printed. Furthermore an addressee can immediately tell if the document has been opened by a third party by simple visual inspection.

One example is the so called Z fold form which is normally rectangular in shape and is available in a variety of sizes such as A4 and Letter. Typically this type of form has two parallel fold lines running laterally across the document, splitting the page into 3 portions. These portions are normally substantially the same size. The adhesive or cohesive deposits are typically located on both sides of the document close to the document edges and in the proximity of regions of the form where fold lines will be made. A particular arrangement of cohesive deposits, together with the fold lines, dictates how the form is folded and sealed, and hence the quality of the seal and the level of security of the document. A particular arrangement may be desirable to meet local post office requirements.

A combination of private and public information is printed onto one side of the form. For example confidential information such as salary details is printed onto the two lower portions of the form whilst public address information is printed on to the upper portion. The form is then Z folded such that the confidential information on the two lower portions is concealed whilst the address information on the upper portion is exposed. The form is then sealed and posted to an addressee via the local postal system or delivered via a company's internal mail system.

Z folded documents normally include one or more lines of weakness or tear lines close to the edges. The recipient of the sealed document can open it by tearing along the lines of weakness to expose the private information inside. If the sealed document is opened by a person other than the addressee, either by tearing along the lines of weakness or by peeling the bonded portions apart, the addressee will be aware of the intrusion when the document is visually inspected. If the document is peeled open a visible paper tear results.

When tearing along lines of weakness a ragged edge often results making the opened document look untidy. This is particularly undesirable when the information contained in the form is to be kept in a file. Such a document can only be used once as the process of opening destroys the means of sealing the document. Furthermore opening a sealed document by tearing along lines of weakness removes a proportion of the document and therefore reduces the potential printing area which carries information. Also, the apparatus required for such known systems can prove unnecessarily uneconomical in operation and construction.

There are a number of pressure sealing devices in the art which are arranged to activate cohesive deposits on a business form and securely seal the folded document and which exhibit the above features.

For example in EP 1 038 694 a folded document having pressure activated cohesive is fed through an arrangement of either two or three pressure sealing rollers. In one embodiment there are three pressure sealing rollers, and the rollers are arranged in an L shape forming two instances of pressure application. The folded form passes through the first and second rollers and is held in a substantially vertical chute above the nip of the first and third rollers. The form is then directed between the first and third rollers to complete the activation of the cohesive. To activate the cohesive this device operates above a pressure of lOOlbs/linear inch.

The subject matter of EP 1038 694 comprises two rollers having parallel axes which define a nip which supplies sufficient pressure to the folded form to activate the pressure activated cohesive and further comprising a means of holding a business form in a manner distinct from the nip but so that the business form will automatically be engaged by and pass through the nip

upon operation of the rollers. The rollers may be arranged to operate reversibly and therefore pass the form between the rollers more than once.

US 6 179 952 presents a pressure sealing device comprising three pressure sealing rollers having substantially parallel axes of rotation and which are substantially vertically aligned. The folded form is passed between the first and second rollers and is then directed between the second and third rollers. The operating pressure between each set of rollers is between 100 and 200 lbs/ linear inch.

The above mentioned pressure sealing devices apply sufficient pressure to the folded business forms to activate the cohesive deposits. The magnitude of the operating pressure supplied is deliberately set to ensure that adequate cohesive bonds are formed such that the cohesive bonds have a greater shear strength than the cohesive paper interface, such that any attempt to peel the business form open will result in paper tear rather than disassociation of the cohesive bond. It is the adequacy of these bonds that makes the business document secure and suitable for sending confidential information.

Accordingly the present invention seeks to provide an improved pressure sealing apparatus for producing sealed business forms comprising cohesive deposits.

According to one aspect of the present invention there is provided an apparatus for pressure sealing documents having a paper substrate, at least one fold line therein and a plurality of cohesive deposits bonded to the paper substrate, said apparatus comprising a means of applying pressure to at least one edge of a folded document wherein the magnitude of the pressure applied by the pressure sealing means to the at least one edge of the folded document is less than 100lbs per linear inch.

The resultant seal along the said at lest one edge of the document from the above apparatus provides a neat, semi-secure means of sealing at least on edge of a folded document for conveying information to an addressee which is personalised yet does not necessarily possess a confidential quality. As the sealed document is easily opened it obviates the need for lines of

weakness.

Advantageously the apparatus can further comprise means for folding business forms along predetermined fold lines and means of transporting a folded document to a position where it can be fed into the pressure sealing means. Printers, in particular printers arranged for simplex printing, may also be incorporated into the apparatus, together with sheet feeders and form stackers to produce a fully integrated system.

In one embodiment the apparatus can be adapted to handle business forms containing inserts.

Such an embodiment further comprises a conventional inserter device.

Preferably the pressure applied to the at least one edge of the folded document by the pressure sealing means is between 50 and lOOlbs per linear inch. In another embodiment the pressure applied is between 65 and 851bs per linear inch.

Preferably in one embodiment the means of applying pressure to at least one edge of the folded document comprises first and second pressure sealing rollers. The first and second pressure sealing rollers can be arranged to rotate about substantially parallel first and second axes of rotation and comprise a means of rotatably driving at least one of said rollers. The pressure sealing rollers are further arranged to receive and pass there between the folded document.

Since this apparatus operates at lower pressures than conventional document pressure sealing devices a lower specification product can be produced which is cheaper to manufacture than conventional devices. For example the pressure sealing rollers can be made from rubber or a rubber compound. In conventional devices the rollers are typically made from steel to withstand the higher operating pressures.

Advantageously in one embodiment the folded document only passes between the first and second pressure sealing rollers once. This feature significantly increases the throughput of the apparatus compared with conventional pressure sealing devices and obviates the need for reversible driving means and/or additional pressure sealing rollers.

In one embodiment the first and second pressure sealing rollers are substantially identical and have a length dimension greater than or equal to the extent of the leading edge of the folded document passing between the rollers. In another embodiment the first and second pressure sealing rollers each comprise a plurality of axially aligned and axially spaced pressure sealing wheels.

The means for folding the document may comprise at least one driving roller. This roller may pinch a buckled document to create a fold line.

According to a second aspect of the present invention there is provided an apparatus for pressure sealing documents having a paper substrate, at least one fold line therein and a plurality of cohesive deposits bonded to the paper substrate, said apparatus comprising a means of applying pressure to at least one edge of a folded document wherein the magnitude of the pressure applied to the folded document by the pressure sealing means is such that cooperating cohesive deposits are activated to form bonds which are weaker than bonds at the cohesive paper substrate interfaces and weaker than the shear strength of the paper thereby allowing a sealed document to be peeled open without the cohesive deposits substantially disassociating themselves from the paper substrate.

The means of applying pressure to at least one edge of the folded document comprises first and second pressure sealing rollers arranged to rotate about substantially parallel first and second axes of rotation and arranged to receive and pass there between the folded document, and a means of rotatably driving at least one of said rollers.

According to a particular embodiment of the present invention there is also provided second means for applying pressure to a region of the paper substrate having a plurality of cohesive deposits bonded thereto and arranged to apply a pressure which is greater than 100lbs per linear inch.

Preferably the second pressure sealing means applies a pressure between 150 and 2201bs per linear inch. In another embodiment the second pressure sealing means applies a pressure

between 170 and 2001bs per linear inch.

In one embodiment the second means for applying pressure to a region of the paper substrate comprises first and second pressure sealing rollers. The first and second pressure sealing rollers can be arranged to rotate about substantially parallel first and second axes of rotation and comprise a means of rotatably driving at least one of said rollers. The pressure sealing rollers are further arranged to receive and pass there between the folded document.

In a preferred embodiment the first and second pressure sealing rollers each comprise pairs of axially spaced pressure sealing wheels.

According to a yet another embodiment of the present invention there is also provided a second pressure sealing means arranged to apply pressure to a region of the paper substrate having a plurality of cohesive deposits bonded thereto and wherein the magnitude of the pressure applied to the folded document by the second pressure sealing means is such that cooperating cohesive deposits are activated to form bonds which are stronger than bonds at the cohesive paper substrate interfaces and stronger than the shear strength of the paper.

According to a third aspect of the present invention there is provided a method of pressure sealing documents having a paper substrate and a plurality of cohesive deposits bonded to the paper substrate, said method comprising the steps: folding the document so that respective cohesive deposits superimpose and applying pressure to at least one pair of superimposed cohesive deposits wherein the magnitude of the pressure applied is such that superimposed cohesive deposits are activated to form bonds which are weaker than bonds at the cohesive paper substrate interfaces and weaker than the shear strength of the paper thereby allowing a sealed document to be peeled open without the cohesive deposits substantially disassociating themselves from the paper substrate.

Preferably the step of applying pressure to at least one pair of superimposed cohesive deposits is performed using apparatus according to the first aspect of the present invention. The pressure applied to the document is less than I OOlbs per linear inch and is preferably 50-lOOlbs per linear

inch. Alternatively the step of applying pressure to at least one pair of superimposed cohesive deposits can be performed using apparatus according to the second aspect of the present invention.

Advantageously, the method also includes applying a second pressure to at least one pair of superimposed cohesive deposits, wherein the magnitude of second pressure is such that superimposed cohesive deposits are activated to form bonds which are stronger than bonds at the cohesive paper substrate interfaces and stronger than the shear strength of the paper. In particular the magnitude of the second pressure is typically in the range 150-2201bs per linear inch and preferably in the range 170-2001bs per linear inch.

The resultant pressure sealed document produced by the apparatus according to the first and second aspects of the present invention or by the method according to the third aspect of the present invention can comprise a paper substrate having at least one fold therein, a plurality of cohesive deposits bonded to the paper substrate and at least one pair of superimposed cohesive deposits bonded together through the application of pressure wherein the bonds between the superimposed cohesive deposits are weaker than bonds at the cohesive paper substrate interfaces and weaker than the shear strength of the paper thereby allowing the document to be peeled open without the cohesive deposits substantially disassociating themselves from the paper substrate.

Since no paper is tom from the sealed document along lines of weakness a larger surface area for carrying information is provided. This feature is particularly advantageous for applications where there is a need to maximise the amount of information carried on a given document.

This type of document is particularly useful when the information contained in the document is personalised yet does not necessarily possess a confidential quality. Such information includes times of medical/dental/business appointments, purchase information, lists of books on loan from a library or notification of fines for over due books. A significant proportion of business information transactions are of this nature: for example the sharing of non-confidential project information within or between departments, non-confidential purchases such as office equipment and the distribution of rotas. It may be desirable to keep such information on record. Such

information requires a lesser degree of security than confidential information.

Alternatively, the resultant pressure sealed document can comprise a paper substrate having at least one fold therein, a plurality of cohesive deposits bonded to the paper substrate and at least one pair of superimposed cohesive deposits bonded together through the application of pressure wherein the bonds between the superimposed cohesive deposits along at least one edge of the document are stronger than bonds at the cohesive paper substrate interfaces and stronger than the shear strength of the paper and the bonds between the superimposed cohesive deposits along at least another edge of the document are weaker than bonds at the cohesive paper substrate interfaces and weaker than the shear strength of the paper.

With this arrangement one or more, and for example the shorter, edges of the document can be removed by tearing along lines of weakness in the document whereas bonds along the longer edge can be easily broken by peeling the document open without the cohesive deposits substantially disassociating themselves from the paper substrate.

An embodiment of the present invention will now be described with reference to the accompanying drawings by way of example only, wherein: Figures la and 1 b show the front and back respectively of a conventional business form having cohesive deposits, two fold lines and arranged for Z folding; Figure 2 shows a first embodiment according to the first aspect of the present invention; Figure 3 shows an integrated printer-pressure sealing system according to the first aspect of the present invention; Figure 4 shows a second embodiment according to the first aspect of the present invention ; and Figure 5 shows a plan view of the embodiment of Figure 4.

Like reference numbers in each of the figures indicate common features.

Figures la and 1 b show the front and back views of a conventional business form 1 comprising

pressure activated cohesive deposits 2 and two fold lines 3,4. Folding the form 1 along fold line 3 or fold line 4 has the effect of superimposing respective cohesive deposits 2. The cohesive deposits 2 used on such forms typically requires pressures between 100-2001bs per linear inch for full activation. That is for superimposed cohesive deposits 2 to form secure bonds which are stronger than the shear strength of the paper substrate.

Figure 2 shows first and second pressure sealing rollers 5,6 mounted for rotation about their respective axles 7,8.

The pressure sealing rollers 5,6 are radially aligned and can be arranged to touch or have a very small gap between their peripheries, typically in the range 0.00 to 0. 05mm (0.000 to 0.002 inches). The first pressure sealing roller 5 is resiliently mounted. The axle 7 is rotatably mounted to a frame member 9. The frame member 9 and/or the axle 7, and hence the first pressure sealing roller 5, is biased towards the second pressure sealing roller 6 by a spring 10.

The axle 8 supporting the second pressure sealing roller 6 is rotatably mounted to a second frame member (not shown) and is constrained from moving displaceably.

It will be apparent to the skilled person that the axles 7,8 can alternatively be integrally formed parts of pressure sealing rollers 5,6 respectively. It will also be apparent to the skilled person that the first pressure sealing roller 5 can be constrained from moving displaceably and the second pressure sealing roller 6 can be biased towards the first pressure sealing roller 5,6.

The folded business form 1 comprising cohesive deposits 2 is presented to the pinch point 11 formed by the proximity of the curved surfaces of the pressure sealing rollers 5,6. The pressure sealing rollers 5,6 are rotatably driven. Peripheral portions of the pressure sealing rollers 5,6 engage the folded business form I at the pinch point 11 and draw the folded business form 1 through the gap between the rollers 5,6. The rollers 5,6 exert a pressure of between 65-85 Ibs per linear inch on the form 1 and hence the superimposed cohesive deposits 2.

As the strength of the required cohesive bond is significantly weaker than the strength of the seal formed by conventional sealing devices the operating pressure of the apparatus is significantly

lower than conventional devices. Accordingly the pressure sealing rollers 5,6 are made from rubber. Alternatively, the rollers 5,6 can be made from a rubber compound or plastics material. Where appropriate the rollers 5,6 can be finished or coated to provide a sufficient coefficient of friction to prevent the business form I from slipping. Furthermore the present invention has the advantage that the folded business form 1 only has to pass between the pressure sealing rollers 5,6 once to obtain the required bond strength.

Consequently machines manufactured to this specification can be smaller, lighter and cheaper to manufacture than conventional machines since only one set of pressure sealing rollers 5,6 is required and no facility for reversibly passing the form 1 between rollers 5,6 is necessary.

The pressure sealing rollers 5,6 are geared together to ensure that there is no slippage thereof.

Figure 3 shows an integrated system comprising a business form feeder 12, a printer 13, a folding device 14, a pressure sealing apparatus according to the embodiment of Figure 1 and a means for collecting and storing the sealed business forms 16. Optionally the system can also include a device for inserting separate documents to be enclosed within the sealed business forms 1.

Blank business forms 1 are drawn into the printer 13 from the feeder 12. The printer 13 prints personalised information on mid and lower regions of the form 1 and address information on an upper region of the form 1, on one side only. The form 1 is then passed to the folding device 14 where it is folded in the appropriate places. For example for a Z fold form 1 is folded twice arranging the form 1 into three portions such that the address information remains exposed and the personalised information is concealed. Furthermore the form 1 is folded such that respective cohesive deposits 2 are superimposed. A conventional Z fold business form 1 has cohesive deposits 2 which are symmetrically arranged about a fold line 3 (or 4), on two adjacent portions of the form I and on one particular side of the form 1 (see Figures la and lob).

The folded fonn 1 is then passed to the pressure sealing apparatus 15. The apparatus comprises two pressure sealing rollers 5,6 which apply a pressure of less than 100lbs per linear inch to the folded form. This application of pressure activates the cohesive deposits 2 on the folded form

1 to create bonds between the superimposed cohesive deposits 2 thereby sealing the form 1.

The bonds formed between superimposed cohesive deposits 2 by the application of pressure are weaker than the bonds between the paper substrate and the cohesive deposits 2 and are also weaker than the shear strength of the paper substrate. This arrangement allows the sealed form 1 to be peeled open by breaking the bonds formed between superimposed cohesive deposits 2 without the cohesive deposits 2 separating from the paper substrate or the paper bonded to the cohesive deposits 2 tearing away from the majority of the form 1. As a result no tear marks are produced when the form 1 is opened.

Conventional pressure sealed forms 1 are arranged to produce paper tears if the sealed form 1 is peeled open. This usually occurs because the shear strength of the paper in the region of the cohesive deposits 2 is lower than strength of the pressure activated cohesive bonds and lower than the bonds formed between the cohesive deposit 2 and the paper substrate.

Since the form 1 can be opened by breaking the bonds formed during the pressure sealing process no additional tear lines (lines of weakness) are needed to access the personalised information.

This arrangement provides a much neater opened form 1 without the untidy edges often produced by tear lines.

The sealed form 1 is temporarily stored in a stacker 16.

It will be appreciated by a skilled man that this invention can be easily adapted to seal other types of forms 1 such as the so called C fold and V fold forms. Furthermore because opening the sealed form 1 does not destroy the document, the form 1 can be used more than once. This may be particularly useful when sharing non-confidential project information within organisations where additional information can be incorporated into the business form 1, which can be then resealed and passed to other colleagues.

It will also be appreciated that other materials can be used to produce the pressure sealing rollers 5,6 which are cheaper and lighter alternatives to the steel rollers used in conventional pressure

sealing devices.

Figures 4 and 5 should be read in conjunction and illustrate a further embodiment of the invention. Figure 4 shows the two pressure sealing rollers 5,6 of Figure 2 and again arranged for rotation on the parallel axles 7,8. As before, the axle 7 is rotatably attached to a frame member 9 and spring 10 biases the frame member 9 and hence pressure sealing roller 5 toward pressure sealing roller 6.

Figure 5 shows a plan view of the arrangement of Figure 4.

In addition, the embodiment of Figure 4 also includes pressure sealing wheels 12,13, comprising cooperating pairs of wheels 12a, 13a ; 12b, 13b (not shown), and which are arranged to engage the folded document upon exit from the rollers 5,6 in the direction of arrow A, as is described below.

A folded document 1 comprising superimposed cohesive deposits is presented to the pinch point 11 formed by the pressure sealing rollers 5,6. Rotation of the pressure sealing rollers 5,6 draws the folded document 1 between the rollers 5,6 thereby applying a pressure between 65-851bs per linear inch to the document 1.

This application of pressure is to the entire folded document I and at this stage the document 1 could be simply peeled open.

However, as mentioned, the document 1 then passes to a pair of pressure sealing wheels 12,13 along a path represented by the arrow marked A. The pressure sealing wheels 12,13 each comprise a pair of wheels (see 12a and 12b in Figure 5) mounted on parallel axles 14 and 15 respectively. The wheels 12a and 12b are set apart by a predetermined distance along axle 7. This distance is determined by the distance between cohesive deposits 2 located along the short edges 19 of the folded document 1 in the illustrated example. The pressure sealing wheels 12, 13 are therefore arranged only to apply pressure to the areas of the document 1 alongside the short edges 19 of the folded document 1. The pressure sealing wheels 13 mounted on axle 15

are set the same distance apart as wheels 12a and 12b such that two pinch points 18 are formed for receiving the document 1.

The cohesive deposits 2 alongside one of the short edges 19 of the folded document 1 are aligned with the pressure sealing wheels 12a and 13a and the cohesive deposits 2 alongside the other short edge 19 of the folded document 1 are aligned with the other pair of sealing wheels. The document 1 is then presented to the pressure sealing wheels 12,13 at the pinch points 18. The pressure applied to the cohesive deposits 2 alongside the short edges 19 is approximately 2001bs per linear inch. The bonds formed by cooperating cohesive deposits 2 by the application of pressure from the pressure sealing wheels 12,13 form are stronger than shear strength of the paper and stronger than the bonds at the paper cohesive interfaces.

The resultant sealed document I has strong seals along its shorter edges 19 and a weak seal along the longer edges 20. To open a document 1 sealed in this way the shorter edges 19 are tom off and then the seals along the longer edges 20 are broken by peeling apart. Advantageously, lines of weakness such as perforation or tear lines are provided adjacent the cohesive deposits 2 to allow the shorter edges 19 to be torn open.

This document 1 has the advantage that it is immediately obvious to a recipient if the document 1 has been opened by a third party and also it provides for a greater printing area for carrying information as no tear line (line of weakness) is required along one of the long edges of the folded document 1.

Claims

1. An apparatus for pressure sealing documents having a paper substrate, at least one fold line therein and a plurality of cohesive deposits bonded to the paper substrate, said apparatus comprising a means of applying pressure to at least one edge of a folded document wherein the magnitude of the pressure applied by the pressure sealing means to the at least one edge of the folded document is less than ICOlbs per linear inch.

2. An apparatus according to claim I wherein the magnitude of the pressure applied to the at least one edge of the folded document is 50 to 100lbs per linear inch.

3. An apparatus according to any one of claims 1 and 2 the magnitude of the pressure applied to the at least one edge of the folded document is 65 to 85lbs per linear inch.

4. An apparatus according to any one of the preceding claims wherein the means of applying pressure to at least one edge of a folded document comprises first and second pressure sealing rollers.

5. An apparatus according to claim 4 wherein the first and second pressure sealing rollers are arranged to rotate about substantially parallel first and second axes of rotation, are further arranged to receive and pass there between the folded document and comprise a means of rotatably driving at least one of said first and second pressure sealing rollers.

6. An apparatus according to any one of claims 4 and 5 wherein the folded document only passes between the first and second pressure sealing rollers once.

7. An apparatus according to any one of claims 4 to 6 wherein the pressure sealing rollers are made from rubber.

8. An apparatus according to any one of claims 4 to 6 wherein the pressure sealing rollers are made from a rubber compound material.

9. An apparatus according to any one of the preceding claims comprising second means for applying pressure to a region of the paper substrate having a plurality of cohesive deposits bonded thereto and arranged to apply a pressure which is greater than 100lbs per linear inch.

10. An apparatus according to claim 9 wherein the second pressure sealing means applies a pressure between 150 and 2201bs per linear inch.

11. An apparatus according to claim 9 wherein the second pressure sealing means applies a pressure between 170 and 2001bs per linear inch.

12. An apparatus according to any one of claims 9 to 11 wherein the second means for applying pressure to a region of the paper substrate comprises first and second pressure sealing rollers can be arranged to rotate about substantially parallel first and second axes of rotation and comprise a means of rotatably driving at least one of said rollers and are further arranged to receive and pass there between the folded document..

13. An apparatus according to claim 12 wherein the first and second pressure sealing rollers each comprise pairs of axially spaced pressure sealing wheels.

14. An apparatus for pressure sealing documents having a paper substrate, at least one fold line therein and a plurality of cohesive deposits bonded to the paper substrate, said apparatus comprising a means of applying pressure to at least one edge of a folded document wherein the magnitude of the pressure applied to the folded document by the pressure sealing means is such that cooperating cohesive deposits are activated to form bonds which are weaker than bonds at the cohesive paper substrate interfaces and weaker than the shear strength of the paper thereby allowing a sealed document to be peeled open without the cohesive deposits substantially disassociating themselves from the paper substrate.

15. An apparatus according to claim 14 wherein the means of applying pressure to at least one edge of the folded document comprises first and second pressure sealing rollers arranged to rotate about substantially parallel first and second axes of rotation and arranged to receive and pass there between the folded document, and a means of rotatably driving at least one of said rollers.

16. An apparatus according to any one of claims 14 and 15 comprising a second pressure sealing means arranged to apply pressure to a region of the paper substrate having a plurality of cohesive deposits bonded thereto and wherein the magnitude of the pressure applied to the folded document by the second pressure sealing means is such that cooperating cohesive deposits are activated to form bonds which are stronger than bonds at the cohesive paper substrate interfaces and stronger than the shear strength of the paper.

17. A method of pressure sealing documents having a paper substrate and a plurality of cohesive deposits bonded to the paper substrate, said method comprising the steps: folding the document so that respective cohesive deposits superimpose and applying pressure to at least one pair of superimposed cohesive deposits wherein the magnitude of the pressure applied is such that superimposed cohesive deposits are activated to form bonds which are weaker than bonds at the cohesive paper substrate interfaces and weaker than the shear strength of the paper thereby allowing a sealed document to be peeled open without the cohesive deposits substantially disassociating themselves from the paper substrate.

18. A method of pressure sealing documents according to claim 17 wherein the step of applying pressure to at least one pair of superimposed cohesive deposits is performed using the apparatus of any one of claims 1 to 8.

19. A method of pressure sealing documents according to claim 17 wherein the step of applying pressure to at least one pair of superimposed cohesive deposits is performed using the apparatus of any one of claims 14 and 15.

20. A method of pressure sealing documents according to any one of claims 17 to 19 comprising the step of applying a second pressure to at least one pair of superimposed cohesive deposits, wherein the magnitude of second pressure is such that superimposed cohesive deposits are activated to form bonds which are stronger than bonds at the cohesive paper substrate interfaces and stronger than the shear strength of the paper.

21. A method of pressure sealing documents according to claim 20 wherein the magnitude of the second pressure is between 150-2201bs per linear inch.

22. A method for pressure sealing documents as substantially as hereinbefore described with reference to the accompanying figures.

22. A method of pressure sealing documents according to claim 20 wherein the in the magnitude of the second pressure is between 170-2001bs per linear inch.

23. A document handling system comprising a printer, a folding device and a pressure sealing apparatus according to claims 1 to 13.

24. A document handling system comprising a printer, a folding device and a pressure

sealing apparatus according to claims 14 to 16.

1 25. An apparatus as substantially as hereinbefore described with reference to the accompanying figures.

26. A method for pressure sealing documents as substantially as hereinbefore described with reference to the accompanying figures.

Amendments to the claims have been filed as follows

1. An apparatus for pressure sealing documents having a paper substrate, at least one fold line therein and a plurality of cohesive deposits bonded to the paper substrate, said apparatus comprising a means of applying pressure to at least one edge of a folded document wherein the magnitude of the pressure applied by the pressure sealing means to the at least one edge of the folded document is less than 100lbs per linear inch (1785.79 Kg per metre), wherein the magnitude of the pressure applied to the folded document by the pressure sealing means is such that cooperating cohesive deposits are activated to form bonds which are weaker than bonds at the cohesive deposit to paper substrate interfaces and weaker than the shear strength of the paper substrate thereby allowing a sealed document to be peeled open without the cohesive deposits substantially disassociating themselves from the paper substrate, and without the paper substrate itself shearing.

2. An apparatus according to claim 1 wherein the magnitude of the pressure applied to the at least one edge of the folded document is 50 to 100lbs per linear inch (892.89 to

1785.79 Kg per metre).

3. An apparatus according to any one of claims 1 and 2 the magnitude of the pressure

applied to the at least one edge of the folded document is 65 to 851bs per linear inch (1160. 76 to 1517. 92 Kg per metre).

9. An apparatus according to any one of preceding claims comprising a second pressure sealing means arranged to apply pressure to a region of the paper substrate having a plurality of cohesive deposits bonded thereto and wherein the magnitude of the pressure applied to the folded document by the second pressure sealing means is such that cooperating cohesive deposits are activated to form bonds which are stronger than bonds at the cohesive deposit to paper substrate interfaces and stronger than the shear strength of the paper.

10. An apparatus according to claim 9 wherein said second means for applying pressure is arranged to apply a pressure which is greater than lOOIbs per linear inch (1785.79 Kg per metre).

11. An apparatus according to claim 10 wherein the second pressure sealing means applies a pressure between 150 and 2201bs per linear inch (2678.68 and 3928. 74 Kg per metre).

12. An apparatus according to claim 11 wherein the second pressure sealing means applies a pressure between 170 and 2001bs per linear inch (3035.84 and 3571.58 Kg per metre).

13. An apparatus according to any one of claims 9 to 12 wherein the second means for applying pressure to a region of the paper substrate comprises first and second pressure sealing rollers which can be arranged to rotate about substantially parallel first and second

axes of rotation and comprise a means of rotatably driving at least one of said rollers and are further arranged to receive and pass there between the folded document.

14. An apparatus according to claim 13 wherein the first and second pressure sealing rollers each comprise pairs of axially spaced pressure sealing wheels.

15. A method of pressure sealing documents having a paper substrate and a plurality of cohesive deposits bonded to the paper substrate, said method comprising the steps: folding the document so that respective cohesive deposits superimpose and applying pressure to at least one pair of superimposed cohesive deposits wherein the magnitude of the pressure applied is such that superimposed cohesive deposits are activated to form bonds which are weaker than bonds at the cohesive deposit to paper substrate interfaces and weaker than the shear strength of the paper substrate thereby allowing a sealed document to be peeled open without the cohesive deposits substantially disassociating themselves from the paper substrate and without the paper substrate shearing.

16. A method of pressure sealing documents according to claim 15 wherein the step of applying pressure to at least one pair of superimposed cohesive deposits is performed using the apparatus of any one of claims 1 to 14.

17. A method of pressure sealing documents according to claim 15 or 16 comprising the step of applying a second pressure to at least one pair of superimposed cohesive deposits, wherein the magnitude of second pressure is such that superimposed cohesive deposits are activated to form bonds which are stronger than bonds at the cohesive paper substrate interfaces and stronger than the shear strength of the paper.

18. A method of pressure sealing documents according to claim 17 wherein the magnitude of the second pressure is between 150-2201bs per linear inch (2678.68 to 3928.74 Kg per metre).

19. A method of pressure sealing documents according to claim 18 wherein the magnitude

of the second pressure is between 170-2001bs per linear inch (2678.68 to 3928. 74 Kg per metre).

20. A document handling system comprising a printer, a folding device and a pressure sealing apparatus to any one of claims 1 to 14.

21. An apparatus as substantially as hereinbefore described with reference to the accompanying figures.