EP0105581B1

EP0105581B1 - Improvements in or relating to bags

Info

Publication number: EP0105581B1
Application number: EP83304584A
Authority: EP
Inventors: Norman Entwistle
Original assignee: Decoflex Ltd
Current assignee: Decoflex Ltd
Priority date: 1982-10-04
Filing date: 1983-08-09
Publication date: 1987-06-03
Also published as: EP0105581A3; EP0105581A2; ATE27588T1; DE3371896D1

Abstract

The invention relates to bags primarily intended for conveying bank notes, which bags can be sealed by adhesive and have security printing adjacent the sealed area which should provide an indication that the bag has been opened after being sealed. The ink used for the security printing is selected so that it will be at least partially dissolved by any solvent which will loosen the adhesive.

Description

This invention has reference to bags capable of receiving contents and which have a surface or part of a surface capable of displaying information about the intended destination of the bag. Some of such bags are also referred to as envelopes but are herein referred to as bags.
In the specification of our British Patent No. 1132419, there is described a bag intended primarily to contain bank notes having a label applied to the outer face of the bag to receive details of the contents of the bag and in which it is arranged that the bag may be closed by a heat seal operation with the bank notes enclosed in the bag.
Such a bag is intended to be used for containing bank notes which have to be moved, for example, from one branch of the bank to another branch. However, it is also required that bags should be available which are capable of being closed, for example, in a store where it is required to circulate money from one department to another and from the store to a bank.
In such an application, the use of a heat sealing machine in each department would not be justified and it is the object of the present invention to provide an improved bag which is capable of being closed in such a way that any attempt to tamper with the bag becomes apparent without the necessity for supplying a heat sealing machine.
Also, in the specification of our British Patent No. 1523933 there is described a bag comprising a pocket part having a surface capable of displaying information about the intended destination of the bag or contents of the bag, a flap part which is capable of being folded over the mouth of the pocket part, and an adhesive strip secured to the bag and comprising a band of adhesive and a covering barrier sheet being removable to permit the band of adhesive to secure the flap to the pocket part when the former is folded onto the latter to retain the bag closed, the side edge of the pocket part and the side of the bag adjacent to the mouth where the flap part overlies the pocket part when the bag is closed being provided with security printing so that once closed, the bag cannot be reopened merely by pulling the adhesive away from the printing and any of the contents extracted and then resealed without the fact being made apparent by the distortion or destruction of some of the security printing.
However, if the edge of the flap is lifted and an adhesive solvent applied carefully, it may be possible to open the bag without pulling away the security printing.
In British Specification No. 12218/1912 there is disclosed a postal envelope wherein a wording is printed on the envelope which printing is made in a water soluble ink which gives an indication that an attempt has been made to open the envelope if the envelope is subject to steaming or moistening.
Belgian Patent Specification No. 505836 discloses an envelope to be sealed in which there is applied to the paper of the envelope substances which leave a visible trace if contacted by steam or vapour liquid.
Belgian Patent Specification No. 376048 describes envelopes having matter printed on them using invisible inks or by a chemical which changes colour when affected by steam.
It is an object of the present invention to provide an improved bag primarily intended to contain bank notes. It is a further object of the invention to provide a bag primarily intended to retain bank notes or documents which is capable of being sealed by adhesive in contact with the security printing and which will give an indication that the bag has been tampered with by the application of solvent to the adhesive to release the adhesive.
Accordingly the present invention provides a bag made of transparent thermoplastics film material such as polyethylene comprising a' pocket part, a flap part which is capable of being folded over the mouth of the pocket part and an adhesive strip (8) secured to the bag and comprising a band of adhesive and a covering barrier sheet (8a), the covering barrier sheet being removable to reveal the band of adhesive, which adhesive is capable of securing the flap part to the pocket part when the former is folded on to the latter to retain the bag closed the side of the bag adjacent to the mouth where the flap part overlies the pocket part when the bag is closed being provided with security printing characterized in that the security printing (10) is printed in ink including a colourant comprising a mixture of soluble dyestuffs and a mixture of solvents which security printing is capable of being dissolved in solvent which makes adhesive (8) go tacky and is located so as to be contacted by the adhesive (8) when the bag is closed and the security printing (10) and adhesive (8) are brought together so that any attempt to open the mouth of the bag by the application of such solvent to the adhesive causes the printing to be contacted by the solvent and blurred and the colour of the security printing changed to give an indication through the transparent flap that the bag has been tampered with.
GB-A-1 523 933 discloses a bag having all of the characteristics of the first part of claim 1.
Bags in accordance with the present invention will now be described with reference to the accompanying drawings wherein:

Figure 1 and Figure 2 show a bag according to the invention; in Figure 1 the bag is in an open position and in Figure 2 the bag is in the closed position. Figure 3 shows a cross-section taken on the line III-III in Figure 2 and Figure 4 is a detailed view.

Referring to Figures 1 and 3 of the drawings, the bag as generally designated 1 is intended to contain bank notes or documents. The bag is formed from a continuous web of thermoplastics film, for example of polyethylene, by folding the continuous web about a fold line 2 which constitutes the bottom of the bag. One folded side 2a is wider than the other folded side 2b with the two folded sides together forming a pocket with part of the longer folded side projecting to form a flap 7. The web is subsequently heat sealed transversely of the web to form the side edges 4, 5 of the bag. A label 6 is applied to the bag and serves as a writing surface to receive handwritten or the like details of the notes contained in the bag. The label is preferably subdivided into areas to receive information about the bank notes contained in the bag and areas to receive the cashier's stamp and the signatures of the persons responsible for the bag. Alternatively, the label may be capable of receiving information about the intended destination of the bag.
The flap 7 is capable of being folded over the outer end of the shorter folded side 2b to close the bag. The inside face of the flap 7 has a line of hot melt adhesive 8 or other similar adhesive strip applied, this is protected by a barrier sheet 8a. Suitable adhesives are found to be those sold as Lunatack D 5762 by H. B. Fuller International or as 089-1011 by National Adhesives, Inc.
In order to make any attempt to tamper with the bag immediately obvious, areas of security printing 9 are provided adjacent to the welded transverse edges 4 and 5 of the bag with the areas of security printing between the respective line of heat seal and the adjacent edge of the bag. This security printing is similar to that described in our prior Patent No. 1365240 except that it is applied to both edges of the bag rather than to the top and bottom of the bag and for example comprises the name of the bank repeated in lines of microprint in close juxtaposition on the bag, or other forms of security printing.
For the same reason, a further area of security printing 10 is provided on the shorter side of the bag adjacent to the mouth in the area to be covered by the flap 7, and this further area is so positioned as to be overlayered by the band of adhesive when the flap is in the closed position. This security printing is printed in soluble ink. Such soluble ink is conveniently ink sold under the Code 7526LHC by Lorrilleaux Bolton Clapham (Liquid Inks) Limited composed of a colourant, a binder and a solvent as follows:

colourant- a mixture of soluble dyestuffs.
diazo yellow- CI reference Solvent Yellow 29-21230
azo chromium complex - CI reference Solvent Red 8-12715
Binder - a polyamide derived from vegetable oil and ethylenediamine.
Solvent - a mixture of ethyl alcohol, aliphatic and aromatic hydrocarbons.

There are countless combinations of dyestuffs which would work; the above is one example.
If an attempt is made to open the flap 7, the fact will be immediately apparent as this area of security printing will be distorted. It is found that the security printing is distorted by application of the following solvents; alcohols, esters, ketones, hydrocarbons, chlorinated hydrocarbons. When such solvents are applied to the security printing such as to soften the adhesive, the ink dissolves and it is apparent that the bag has been tampered with. Any solvent that is capable of rendering the adhesive strip 8 tacky also serves as a solvent for the security printing matter so that if any solvent is applied to the adhesive strip, the solvent will also serve to dissolve some of the security printing to change the colour of the security printing as shown in Figure 4 and given an indication that the bag has been tampered with. It is also desirable but not essential that one of the colourants is more soluble in solvents than the other and this will cause a colour change if the security printing is attacked by solvent.
Additionally, small perforations 10 are formed near the base of the bag to permit the egress of air from the bag to prevent air being trapped within the bag. When it is required to seal the bag, the bank notes having been inserted in the bag, the barrier sheet 8a is removed from the flap 7 of the bag and the flap is then folded upon the end of the shorter folded side 2b at the mouth of the bag. The line of adhesive 8 secures the flap 7 to the shorter folded side 2b.
Alternatively, the adhesive strip can be applied to the shorter side of the pocket near the mouth to secure the flap when the latter is folded over to close the bag. Also, instead of applying a label 6, an area of printing ink suitable to receive written information may be applied to the bag so as to be capable of receiving information about the contents of the bag.

Claims

1. A bag of transparent thermoplastics film material such as polyethylene comprising a pocket part 2a, 2b, a flap part 7 which is capable of being folded over the mouth of the pocket part and an adhesive strip 8 secured to the bag and comprising a band of adhesive and a covering barrier sheet 8a, the covering barrier sheet being removable to reveal the band of adhesive, which adhesive is capable of securing the flap part to the pocket part when the former is folded on to the latter to retain the bag closed the side of the bag adjacent to the mouth where the flap part overlies the pocket part when the bag is closed being provided with security printing characterized in that the security printing (10) is printed in ink including a colourant comprising a mixture of soluble dyestuffs and a mixture of solvents which security printing is capable of being dissolved in solvent which makes the adhesive (8) go tacky and is located so as to be contacted by the adhesive (8) when the bag is closed and the security printing (10) and adhesive (8) are brought together so that any attempt to open the mouth of the bag by the application of such solvent to the adhesive causes the printing to be contacted by the solvent and blurred and the colour of the security printing changed to give an indication through the transparent flap that the bag has been tampered with.

2. A bag according to claim 1 characterised in that the solvent comprises a mixture of ethyl alcohol aliphatic and aromatic hydrocarbons.

3. A bag according to claim 1 or 2 characterised in that security printing (9) is applied to the edges of the bag and is printed by the same ink as the security printing (10) at the side of the bag adjacent to the mouth of the bag.