Abstract:
A package material with a tamper evident feature and methods of manufacture thereof, are disclosed herein. The package comprises a colored primer or lacquer coating applied along a portion of a seal and further comprising a peelable sealant. When opened the peelable sealant is separated from the portion of the seal containing colored primer or lacquer and removes a section of the coating, thus providing a visual indication that the package has been opened.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. application Ser. No. 11/279,497, filed Apr. 12, 2006, now U.S. Pat. No. 7,740,923 claiming priority to European Patent Application No. 05008398.9, filed Apr. 18, 2005, which are incorporated by reference herein in their entirety. 
    
    
     FIELD 
     The invention relates to a package, a food product packaged with the package, as well as a method and a machine for producing a packaging material or for packaging a food product and a packaging material produced thereby. 
     Particularly in the field of packages for food products, it is desirable to provide the consumer with a package, which is both easy to open and re-closable. However, with re-closable packages it is an issue that the package might have been opened and re-closed before the consumer purchases and/or consumes the food product contained in the package. In other words, it is important for the consumer to know whether a third person (or the consumer himself, beforehand) has tampered with or opened the package. This information is important as it will influence the consumer&#39;s decision to purchase the product and/or the consumer&#39;s decision to consume the product despite the fact that the package has been opened and re-closed and the food product contained therein might not be in the original state and might, particularly, not be in a fresh state. 
     BACKGROUND 
     As far as tamper evidence is concerned, it is known to provide additional mechanical features, such as a sticker or a label, which need to be broken in order to open the package. This type of tamper evidence complicates the manufacturing and the packaging process and, moreover, deteriorates the easy to open properties of the package. 
     EP 0 341 699 B1 discloses tamper indicating containers and seals, in which a colorant is at least partially removed, when the seal is first opened, so that the first opening is indicated, and the consumer can realise that the package has been tampered with. A similar tamper evidence seal and tape is disclosed in WO 96/04177. 
     EP 1 288 139 of the Applicant discloses a package for packing food products which is easy to open due to the presence of two easily gripable flaps having a different width. 
     SUMMARY 
     It is an object underlying the invention to provide a package which is improved with regard to its tamper evidence features, as well as a food product packaged therewith. Furthermore, the invention provides a method and a machine for producing a packaging material or for packaging a food product which can produce a package, which comprises improved tamper evidence. Finally, a packaging material produced thereby is also subject matter of the invention. 
     The package according to the invention is described in claim  1 . Preferred embodiments thereof are the subject of the further claims. 
     The package according to the invention comprises, firstly, a substrate. The substrate can be any type of film or foil from any type of suitable material, such as polyethylene or polypropylene or paper coated with a plastic material. In particular, the substrate can advantageously be suitable for the production of so-called flow packs, i.e. packages which are produced by wrapping a foil or film material around a succession of products, sealing the foil or film to itself between products and producing a so-called fin seal parallel to the machine direction, i.e. the direction of the succession of products. The packed products are separated from one another by cutting transversely to the machine direction in the area of the seals, which are formed between the products. 
     In the inventive package, a first and a second surface portion of the substrate are sealed to each other. The first and second surface portion can, for example, be parallel to each other and can, moreover, be parallel to the machine direction and thus constitute the above-described fin seal. These surface portions can be sealed to each other by a cold or heat seal as desired. The seal can be patterned, i.e. the sealant or adhesive producing the seal can be applied in a pattern, such as plural dots, stripes or any other suitable pattern and the first and second surface portions can, moreover, be subjected to embossing in order to improve the strength of the seal. 
     A third surface portion adjacent the first surface portion is at least partially covered by a coating. It can be mentioned that the third surface portion can act as a type of flap or tab adjacent the first surface portion that can be gripped when it is desired to open the package, in order to achieve an easy opening of the seal constituted by the first and second surface portions. It can, moreover, already be mentioned that the coating of the third surface portion has a particular colour in order to provide a tamper evidence feature. In particular, a binding force, between the coating and the substrate, has a first value. This first value will be in a specific relationship with the values of further binding forces, as detailed below, in order to provide the tamper evidence feature. 
     A fourth surface portion is present adjacent the second surface portion and is only partially covered with an adhesive. In a manner corresponding to the third surface portion, the fourth surface portion can be considered as a flap or tab adjacent the second surface portion. Moreover, the fourth surface portion is, furthermore, at least partially in contact with the third surface portion. Thus, at least one of the third and fourth surface portions can easily be gripped when it is desired to open the package and a separating force can be applied to these surface portions in order to separate the sealed first and second surface portions from each other and allow access to the product contained in the package. It is to be noted that the fourth surface portion is only partially covered with an adhesive, so that the fourth surface portion is only partially bonded to the third surface portion. Thus, there are parts of the third and fourth surface portions which are not bonded to each other and which can, therefore, easily be gripped in order to open the package. Thus, the inventive package is easy to open which is beneficial for the consumer. 
     As far as the adhesive is concerned, with which the fourth surface portion is only partially covered, a bonding force between the adhesive and the substrate, as well as the coating, respectively, has a second and a third value, respectively. Both the second and third values are greater than the first value. Since the first value is related to the bonding force between the coating and the substrate, a separation of the third and fourth surface portions from each other will cause the coating to adhere to the adhesive and will, thus, be removed from the third surface portion. This is because, as mentioned above, the bonding force between the adhesive and the substrate as well as the coating is higher than the bonding force between the coating and the substrate. Thus, the adhesive will, firstly, adhere to the fourth surface portion. Secondly, due to the bonding force between the adhesive and the coating, which are at least partially in contact with each other, the coating will adhere to the adhesive and will be removed from the substrate of the third surface portion, because of the relatively low bonding force, having the first value at this interface. 
     Thus, when the package is first opened, the coating is at least partially removed from the third surface portion. For example, the removed part of the coating can represent the word “opened” so that after the first opening, this message is conveyed to the consumer. In a similar manner, also that part of the coating, which stays on the third surface portion, can represent this word or any graphic or written information in order to indicate that the package has already been opened or has been tampered with. It will also be appreciated that a higher opening force will be required for the first opening than for any subsequent openings. This is because during the first opening, the coating will at least partially be removed from the third surface portion. Subsequently, the removed part of the coating adheres to the adhesive on the fourth surface portion and will, also after re-closing, stay on the adhesive of the fourth surface portion. Thus, during subsequent openings, only that part of the adhesive, which adheres to the third surface portion, and not that part of the adhesive, which is covered with the removed coating, needs to be separated from the third surface portion. Due to the reduced surface area, which adheres to the third surface portion, the opening force is reduced and the consumer can additionally “feel” that the package has already been subjected to a first opening. As detailed above, the consumer can also visually recognise this fact, because at least a part of the coating of the third surface portion has been removed. 
     The visual effect is obtained as a colour of the coating is different than a colour of the third surface portion and/or the fourth surface portion and/or the adhesive. When the colour of the coating is different from the colour of the third surface portion, the coating can be partially removed from the third surface portion during the first opening, so that the consumer will realize that only a part of the coating (having a different colour than the third surface portion) has stayed with the third surface portion. This remaining part can convey the “opened” message by exhibiting this or similar word(s), or by representing specific graphic information. Moreover, the colour of the coating can be different from the colour of the fourth surface portion, because the adhesive on the fourth surface portion will at least be partially covered with the coating after the first opening. Therefore, the difference in colour between the coating which adheres, by means of the adhesive, to the fourth surface portion, and the fourth surface portion itself can be used for indicating the first opening and/or tampering. Finally, the surface area of the fourth surface portion, which is covered with adhesive, can be greater than the area of the third surface portion, which covered with coating. Thus, the coating, which has been removed from the third surface portion, can, after the first opening, be surrounded by areas of adhesive on the fourth surface portion. Thus, when a colour difference between adhesive and the coating is present, the first opening or tampering information can be conveyed to the customer in this manner. 
     Thus, the coating and the adhesive are, in the final package, at least partially in contact with each other, so that separating the fourth surface portion from the third surface portion will at least partially remove the coating from the third surface portion. As mentioned, the third and fourth surface portions can represent flaps or tabs which are in contact with each other, so that the coating provided on the third surface portion and the adhesive provided on the fourth surface portion are in contact. Due to the relationship of the various bonding forces described above, the process of separating the fourth surface portion from the third surface portion will at least partially remove the coating from the third surface portion. As detailed above, due to the colour differences, this removal of the coating can provide an indication that the package has been opened or tampered with. 
     As will be appreciated from the above, the measures described herein do not require any separate mechanical features, such as additional stickers or labels. Rather, the coating and the adhesive can easily be applied to the substrate when the substrate, which can, for example, be present as a web, is traveling through the packaging machine, and a succession of products are packaged, for example, in a flow-wrap or flow-pack type package. Moreover, the package according to the invention can be produced in two steps, which can particularly be performed at different locations, with the production of a packaging material being a first step. In connection therewith, a substrate, which can be present as a web, can be coated and/or printed with the above-described adhesives, sealant and coatings such as ink or primer. The packaging material can then be wound to rolls or reels, which can be delivered to a different company, which intends to package their goods with the described packaging material. The company using the packaging material then only has to unwind the packaging material and the goods can be packaged without any additional devices or steps being required during packaging. This advantageously keeps the packaging machinery uncomplicated and the necessary investments for the company using the packaging material low. 
     In particular, the adhesive on the fourth surface portion can be the same as, and can be continuous with, the adhesive which is used for sealing the first and second surface portions to each other and, possibly, further surface portions. Also the coating of the third surface portion can be readily applied to the substrate in the process of packaging food products. It should, moreover, be mentioned that the tamper evidence feature is realized in the third and fourth surface portions, which are adjacent the first and second surface portions, respectively, which are sealed to each other. Thus, the seal, as such, is not affected by the tamper evidence feature. In particular, the seal can be provided in a way to ensure reliable sealing and, preferably, re-closability, whereas the tamper evidence feature, which is present in the third and fourth surface portions, can, substantially independent from the seal, be provided in a reliable and efficient way. 
     In particular, the first and second surface portions, respectively, which form the seal, are preferably not formed in a way to integrate or surround the third and fourth surface portions, respectively, or be surrounded by the latter. Rather, the third surface portion is adjacent the first surface portion and there is, if any, a single borderline between them, which is preferably straight. Moreover, one or more further surface portions can even be present between the first and the third surface portion. The above also is applicable to the relationship between the second and fourth surface portions. In particular, the third and fourth surface portions are preferably formed on free edges of the package, so that they can constitute two gripable flaps. Finally, all of the described surface portions are preferably formed substantially rectangular. The invention is applicable to the package described in EP 1 288 139 A1 of the Applicant, the disclosure of which is, with regard to the package as such, including the seal and flaps thereof, incorporated herein by reference. It should be mentioned that the invention is also applicable to so-called vertical form fill seal bags and pouches. In such types of packages, for example, pieced goods such as candy or small confectionary products can be packaged. In connection with vertical form fill seal bags and pouches, it should be noted that the surface portion comprising the coating can be parallel as well as substantially perpendicular to the machine direction, i.e. the direction, in which the packaging material is conveyed through the machine. This also applies to any horizontal packaging machines. Moreover, one or more of the seal described above can be formed as heat seals instead of cold seals. 
     Preferred embodiments of the inventive package are described in the further claims. 
     As mentioned above, the substrate can be made of any suitable material. Currently, the use of a film for the substrate is preferred, as a film material will advantageously allow the invention to be used with a flow-wrap type of package. 
     Moreover, the invention is not dependent on the first and second surface portions being present on the same side of the substrate. However, it is advantageous if the first and second surface portions are indeed on the same side of the substrate, as an efficient packaging method can be used, as a fin seal can be provided between the first and the second surface portions being on the same side of the substrate. 
     As regards the seal between the first and second surface portions, this can be formed by an adhesive, such as a cold seal, a heat seal, a pressure sensitive glue or any other suitable type of seal. In particular, pressure sensitive glue can be covered with a heat seal lacquer in order to seal the package. In this case, the seal can be broken along the pressure sensitive glue. All of these embodiments represent a reliable and efficient type of seal. 
     Generally, the invention, due to the tamper evidence feature, is exhibiting specific advantages in re-closable packages, so that it is currently preferred that the seal between the first and the second surface portions is re-closable. 
     The first and second surface portions can have a shape and/or structure to provide a completely closed package. For example, the package can be a type of envelope with three permanently closed sides, and the remaining side being closed by the seal between the first and the second surface portions. Because of the flow pack type of package, which is currently preferred for the package described herein, it is, however, preferred that there is a fifth and/or sixth surface portion, which is respectively sealed to itself. As mentioned above, the first and second surface portions can constitute a fin seal. In this type of package, the fifth and/or sixth surface portion can constitute one or two end seals, which are substantially perpendicular to the fin seal. In particular, a relatively wide seal, which is oriented substantially perpendicular to the machine direction, can be provided between two products, and a cut can be made in the area of the end seal in a direction perpendicular to the machine direction, in order to separate two packages, each containing a product, from each other. Thus, the fifth and/or sixth surface portion are preferably substantially perpendicular to the first and/or second surface portions. 
     As it provides advantages, when the third and/or fourth surface portions constitute flaps or tabs which can be used for opening the seal between the first and second surface portions, it is advantageous when the third and/or fourth surface portions or immediately adjacent the first or the second surface portions, respectively. 
     The third and the fourth surface portions are preferably of a different size which implies that one of these surface portions extends beyond the other one. In this manner, it can be easily realized that gripping tabs or flaps are present. Moreover, due to the different extension, one or both of the third and fourth surface portions can be gripped in order to separate them from each other and open the package. In connection with the differing size of the third and fourth surface portions, reference can additionally be made to the above referenced application of the Applicant. 
     Generally, the above-described effects of the coating, based on the colour thereof, can be achieved with any type of coating. However, since the coating essentially has to provide the indicating effect, it is currently preferred that the coating is a primer or an ink, which adheres to the substrate of the package. 
     As regards the amount of coating, tests have shown that the coating can advantageously be applied with 0.5 to 2 g/m 2  with 1.4 to 1.6 g/m 2  being preferred. 
     It has, furthermore, been realized in experiments, that the reliability of the coating being removed from the third surface portion can be improved when the coating is, in addition to the adhesive provided on the fourth surface portion, at least partially covered with an adhesive. In particular, when the adhesive on the fourth surface portion and the adhesive covering the coating are at least partially in contact with each other, the adhesive of the fourth surface portion will at least partially adhere to the adhesive covering the coating and will improve the reliability, with which the coating, which is present underneath the adhesive on the third surface portion, is removed. Moreover, it can be advantageous to have continuous areas, which are covered with adhesive, so that it is advantageous to cover at least a part of the coating on the third surface portion with adhesive. It is to be emphasized that the described feature, namely the coating, in addition to the fourth surface portion, being at least partially covered with adhesive, represents a feature which can be provided on the package described herein, in which the fourth surface portion does not necessarily have to be only partially covered with the adhesive. In other words, in this case, the fourth surface portion can be completely covered with adhesive. The feature, that the coating is at least partially covered with adhesive, can be combined with one or more of the features mentioned above and below as desired. 
     In view of the even higher force for reliably removing a part of the coating from the third surface portion, it is, as mentioned, advantageous if the adhesive on the fourth surface portion and the adhesive covering the coating are at least partially in contact with each other. 
     In this context, the effects can be further improved when the bonding force between the adhesive on the fourth surface portion and the adhesive covering the coating has a fourth value, which is higher than the first value. Thus, the coating on the third surface portion will reliably be removed during first opening. 
     It is currently preferred that the adhesive is a cold seal or a heat seal. In this embodiment the adhesive can be formed continuous with a seal between the first and second, as well as on the fifth and/or sixth, surface portions, which provide advantages with regard to the covering of the required areas of the substrate with the seal. 
     When the adhesive is pressure sensitive glue or adhesive, the packaging of the food product can be facilitated, because the bonding of the adhesive can be realized by pressure, without heat or similar effects being necessary. Furthermore, the adhesive can contribute to the re-closability of the package and the package can be improved in this regard. 
     Experiments have shown that it is advantageous if the adhesive is applied with 3 to 5 g/m 2 , preferably 3.5 to 4.0 g/m 2 . 
     The seal between the first and the second surface portion and/or the seal of the fifth surface portion and/or the seal of the sixth surface portion and/or the adhesive can comprise a pattern. This can reduce the amount of adhesive or sealant, which is required, as the necessary effects can possibly be obtained by a reduced amount of sealant or adhesive, which is, for example, applied in a dot and/or a stripe pattern. 
     As can be taken from above, the relationship between the various values of bonding forces is most relevant for obtaining the desired effects. As regards the absolute values, 0.5 to 1.5 N/15 mm have proven advantageous for the first value of the bonding force. In this context, the given force corresponds to that force, which is necessary to peel a strip of material having a width of 15 mm and being coated with the respective material. This force can, in particular, be measured in accordance with the draft for DIN 55529. 
     The second value of the bonding force can be 4.5 to 7 N/15 mm, as tests have shown. 
     As regards the third value of the bonding force, 2 to 4 N/15 mm, preferably greater than 3 N/15 mm have shown to be advantageous. 
     Finally, 2.5 to 4 N/15 mm are preferred for the fourth value of the bonding force. 
     Generally, the inventive package can be applied to any kind of product. However, for food products, in particular confectionary products, the provision of both re-closability and tamper evidence, which the invention provides, is particularly relevant, so that a food product, particularly a confectionary product, which is packaged with a package, in one of the above-described embodiments, is part of the invention. In this context, the food product can be a tablet, block or bar shaped product. However, the food product can also be one or more pieced goods. 
     The invention is, furthermore, constituted by a method for producing a packaging material or for packaging a food product as described herein. Corresponding to the package, which is to be obtained, at least a first and a second surface portion of a substrate are covered with a sealant. A third surface portion adjacent the first surface portion is covered with a coating and a bonding force between the coating and the substrate has a first value. Moreover, only a part of a fourth surface portion adjacent the second surface portion is covered with an adhesive and a bonding force between the adhesive and the substrate as well as the coating, respectively, has a second and a third value, respectively, both the second and third value being higher than the first value. Moreover, the colour of the coating is different than the colour of third and/or fourth surface portions and/or the adhesive. As described before, these steps can either be part of a method for producing a packaging material or for packaging a food product. When a packaging material is to be produced, the substrate is covered with sealant and coating in the above-described manner. However, there can be applications, where the packaging material is covered with either the sealant or the coating, as well as applications, in which only some of the surface portions are covered with sealant and/or coating. Such embodiments are part of the invention. In practice, further surface portions can be covered at a different location, for example, when the packaging material is to be used for packaging one or more products. In the method for producing a packaging material, the method can comprise the step of winding the packaging material so as to produce a roll or reel material which can then be delivered to the company that intends to use the packaging material for packaging their goods. 
     In the method for packaging the food product, the first and second surface portions are sealed and the coating and the adhesive are at least partially brought in contact with each other. This method provides an efficient and uncomplicated method for producing a package as described above, which is particularly improved with regard to tamper evidence. 
     Preferred embodiments of the inventive method substantially correspond to the preferred embodiments of the package and are described in the further claims. In connection with the inventive method, it should be mentioned separately that the substrate can be conveyed in a machine direction and the first and/or second surface portion can extend substantially in the machine direction, so that they constitute a fin seal. However, the first and/or second surface portions as well as the third and fourth surface portions can also extend substantially perpendicular to the machine direction, in other words in a cross machine direction and can, thus, be formed as end seals of the package. Moreover, the seal between the first and/or a second surface portion as well as the seal of the fifth and/or sixth surface portion can be embossed with a pattern in the method described herein. The embossed pattern can, for example, be one or more lines or stripes, which extend substantially parallel to the length of the respective surface portion. In particular, in a preferred embodiment, embossed lines or stripes extend substantially parallel to the length of both the first and second and the fifth and sixth surface portion. In this context, the length or extension of the respective surface portion is the longer dimension of the surface portion, which can have a substantially rectangular shape. 
     The invention, moreover, provides a machine for producing a packaging material or for packaging a food product which is adapted to carry out the above-described method and/or produce the inventive package or the packaging material described below. Thus, the packaging machine comprises a device for covering at least a first and a second surface portion of a substrate with a sealant. Moreover, the machine comprises a device for covering a third surface portion adjacent the first surface portion with a coating, a coating force between the coating and the substrate having a first value. The machine also comprises a device for covering only part of a fourth surface portion adjacent the second surface portion with an adhesive. With these devices, a packaging material, as described below, can be produced. In this context, not all of the above-described devices do necessarily have to be present. Rather, only one or some of the mentioned devices can be provided in order to produce an intermediate type of packaging material. In particular, the remaining devices can be provided within a packaging machine which is then adapted to “complete” the packaging material and which can, additionally, be adapted to package one or more products. 
     When a packaging machine is to be provided, a device for sealing the first and second surface portion and a device for bringing the coating and the adhesive at least partially in contact with each other are provided. 
     Preferred embodiments of the machine correspond to preferred embodiments of the inventive method and are described in the further claims. The machine can comprise a device for conveying the substrate in a machine direction, the first and/or second surface portions extending substantially in the machine direction. 
     The machine can be kept uncomplicated when the device for covering the first and second surface portions and the device for covering the fourth and/or the fifth and/or the sixth surface portions, are constituted by a single device. Thus, continuous surface portions covered with an adhesive can be formed by a single device. 
     The machine can comprise a printer for covering the described surface portions with the coating in the form of ink or a primer. 
     The invention finally provides a packaging material, in which the first and second, third and fourth surface portions are covered as described above for the final package. Such a packaging material can also have only some of the described surface portions covered in the described manner, and either the coating or the sealant can be applied to the packaging material. The packaging material can be produced and then supplied to the company that intends to use it for packaging goods. In particular, the packaging material can be provided as a reel or roll material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Hereinafter, preferred embodiments of the invention will be described with reference to the drawings, in which: 
         FIG. 1  shows a plan view of the substrate of the inventive package in a first embodiment before closing the package; 
         FIG. 2  shows the substrate of  FIG. 1  after the first opening; 
         FIG. 3  shows a plan view of the substrate of the inventive package in a second embodiment before closing the package; 
         FIG. 4  shows a plan view of the substrate of the inventive package in a third embodiment before closing the package; 
         FIG. 5  shows the substrate of  FIG. 4  after the first opening; 
         FIG. 6  shows a perspective view of a bag which can be produced using the substrate of  FIG. 4 ; 
         FIG. 7  shows a plan view of the substrate of the inventive package in a fourth embodiment before closing the package; 
         FIG. 8  shows the substrate of  FIG. 7  after the first opening; and 
         FIG. 9  shows a perspective view of a bag, which can be produced using the substrate of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     As  FIG. 1  shows, the substrate  12  of the inventive package is, in the preferred embodiment, a substantially rectangular piece of film material. This piece can be part of a web, which is conveyed through a packaging machine in the machine direction A. In the final package, the white area  32 , which is also substantially rectangular and located in the centre of the substrate  12 , will be used to enclose a product  34 . Moreover, in the final package, the package will be sealed by seals, which are formed between a first  14  and a second  16  surface portion as well as by sealing a fifth  28  and a sixth  30  surface portion to itself. On the basis of the above terminology, the seal of the fifth  28  and sixth  30  surface portions  30  constitute end seals, and the seal between the first  14  and the second  16  surface portions can constitute a fin seal. In the embodiment shown, the first, second, fifth and sixth surface portions, which constitute the various seals, form a kind of rectangular frame. In particular, they are, in this preferred embodiment, formed on the same side of the substrate  12 . 
     As can also be taken from the drawings, a third  18  and a fourth  22  surface portion are present adjacent the first  14  and second  16  surface portions, respectively. 
     As described in the above-referenced earlier application of the Applicant, these surface portions can constitute tabs or flaps, which can be gripped by the consumer in order to separate the first  14  and second  16  surface portion from each other in order to open the seal and get access to the contents of the package. As indicated by the colouring of the third  18  surface portion this surface portion  18  is covered with a coating  20 . In the embodiment shown, the coating  20  covers the entire third surface portion  18  but this is not necessary. Furthermore,  FIG. 1  shows an embodiment in which the colour of the coating  20  is remarkably darker than the colour of the substrate  12 , which is visible in the uncovered and uncoated central area  32 . In the embodiment shown, the coating  20  is, moreover, partially covered by an adhesive  26 . In particular, three strips of adhesive, which extend substantially perpendicular in the machine direction A, are applied on the coating  20 . It is to be understood, however, that the strips or stripes can have a different shape and/or size, and the areas, where the adhesive and/or the coating is applied, can have any suitable appearance. 
     In the embodiment shown, the fourth surface portion  22  comprises similar strips of adhesive  24 . In particular, the strips of coating  20  and/or adhesive  26  ( FIG. 1 ) can be present every 10 to 50 mm. In particular, the fourth surface portion  22  is only partially covered with adhesive  24 , so that areas remain free of adhesive, which can be gripped in order to separate the third  18  and fourth  22  surface portions from each other and, as a consequence, separate the first  14  and second  16  surface portions from one another in order to open the package. 
       FIG. 1  shows the substrate before a food product is packaged. In particular, the substrate shown in  FIG. 1  can be part of a packaging material in the form of a web, on which the pattern of sealant, adhesive and coating is repeated several times. In the case shown, the web extends in the machine direction A, with the fifth surface portion  28  of a first substrate being substantially adjacent the sixth surface portion  30  of another substrate. When a food product is to be packaged, the product indicated at  34  is placed on the central area  32  of the substrate, and the substrate is wrapped around the food product  34 . During this process, the fifth  28  and sixth  30  surface portions are sealed to themselves, and the first  14  and second  16  surface portions are sealed to each other. 
     Moreover, the third  18  and fourth  22  surface portions come in contact with each other. In particular, the adhesive  24 , partially covering the fourth surface portion  22 , contacts the adhesive  26  provided on the coating  20 . It should be mentioned that this adhesive  26  is not absolutely necessary. Rather, the adhesive  24  on the fourth surface portion  22  can be in direct contact with parts of the coating  20 . When such a package is first opened, the third  18  and fourth  22  surface portions are separated from each other, and the adhesive  24 , provided on the first surface portion  22 , removes a part of the coating  20 . 
       FIG. 2  shows the substrate corresponding to that of  FIG. 1  after the first opening. As can be seen, the adhesive  24  on the fourth surface portion  22  is covered with coating, which has been removed from the third surface portion  18 . Since the colour of the coating  20  differs from that of the fourth surface portion  22 , the consumer can see that the package has been opened. In particular, the adhesive  24  on the fourth surface portion  22  could be applied in a manner to show the word “opened”, so that the “opened” message is displayed after first opening. 
     In the embodiment shown, the coating  20  also has a different colour than the third surface portion  18 . Therefore, in view of the fact that the entire third surface portion  18  is, in the embodiment shown, covered with a coating  20 , strips  36  on the third surface portion  18 , which are free of coating, are visible. In the embodiment shown, the substrate has a uniform, light, preferably white colour throughout all surface portions, so that the above effects are obtained. However, it is also sufficient if the coating has a colour, which is different from that of the third  18  or the fourth  22  surface portion. Moreover, when the area of the fourth surface portion  22 , which is covered with adhesive  24 , is greater than the area of the third surface portion  18 , which is covered with coating  20 , it is sufficient if the colour of the coating  18  differs from that of the adhesive  24 . Since all of the coating will be removed from the third surface portion, the difference of colour between the coating, which covers part of the adhesive on the fourth surface portion  22 , and the surrounding adhesive will be visible. 
     When the package is to be re-closed, the first  14  and second  16  surface portions can again be sealed to each other, and the fifth  28  and sixth  30  surface portion can be sealed to themselves. This provided re-closability and requires a certain opening force also for subsequent openings. However, as can be taken from the drawing, the adhesive  24  on the fourth surface portion  22  is covered with coating, which will not adhere to the third surface portion  18 . Thus, there is no bonding force active in this area and the consumer can also feel that there is a lower opening force than for the first opening. This provides tamper evidence in addition to the above-described visual effects. It is also evident that the substrate does not necessarily have to be brought into the state shown in  FIG. 2 , when the package is to be opened. Rather, if only a part of the product, such as a part of a chocolate bar or tablet is to be consumed, it will be sufficient if the seal between the first  14  and the second  16  surface portions is opened partially, and the adjacent end seal, i.e. the seal of the fifth  28  or the sixth  30  surface portion is opened. When the remainder of the product is to be kept in the re-closed package, only the opened seals have to be re-closed. In particular, when the package is opened only partially, only one or two of the stripes of coating can be removed. In the case of a different pattern of coating  20  and/or adhesive  24  and  26  on the fourth surface portion  22  and the coating  20 , respectively, only part of the coating is removed during partial opening, which still indicates that the package has at least been partially opened. 
     As can be taken from  FIG. 3 , the second embodiment of the inventive package differs from the first embodiment only with regard to that part of the third surface portion  18 , which is covered with a coating  20 . In particular, in the embodiment shown in  FIG. 3 , only three strips are covered with coating. In the embodiment shown, the location and size of the strips correspond to the location and size of the strips of adhesive  26  covering the coating  20  in the embodiment of  FIG. 1 . However, it is to be understood that the pattern, with which the coating  20  is applied to the third surface portion  18 , could be completely different. Moreover, in the embodiment shown in  FIG. 3 , the strips of coating  20  are, at least to a large extent, covered by adhesive  26 , similar to the strips of adhesive  26  in the embodiment of  FIG. 1 . As noted above, these strips of adhesive  26  are not necessary. Rather, also the strips of adhesive  24 , which are provided on the fourth surface portion  22 , will come into contact with the strips of coating  20 , when the package is closed, in order to package a product indicated at  34 . 
     Due to the relationships of the various bonding forces, the adhesive  24  of the fourth surface portion  22  will remove the coating  20  from the third surface portion  18  in order to provide tamper evidence. In particular, as the fourth surface portion  22  adheres to the third surface portion  18 , due to the adhesive  24 , the coating  20  is not visible to the consumer before the first opening. After the first opening, or when the package has been tampered with, the coating  20  covers the adhesive  24  on the fourth surface portion  22  and is, therefore, visible. In particular, the coating could form the word “opened” in order to inform the consumer that there has been a first opening. 
     In the embodiment shown in  FIG. 3 , substantially all of the coating provided on the third surface portion  18  can be removed. Therefore, the colour of the coating  20  is in this case different from that of the fourth surface portion  22  and/or the adhesive  24  provided on the fourth surface portion  22 , in order to make the coating visible, which has been removed from the third surface portion  18  and adheres to the adhesive  24  on the fourth surface portion  22 . Thus, the appearance of the fourth surface portion  22  after the first opening will substantially correspond to that of the fourth surface portion  22  of the first embodiment, shown in  FIG. 2 , whereas the third surface portion  18  will be substantially free of adhesive and coating  20 . Both of the embodiments described above can be produced easily and efficiently and products, in particular food products, can be packaged with the above-described tamper evidence features being applied in line, i.e. during packaging the product. As an alternative, the described substrate can be part of a packaging material comprising a plurality of portions constituting plural substrates, with which a plurality of food products can be packaged with the final package exhibiting the described tamper evidence features. 
       FIG. 4  shows a plan view of the substrate  12  in a second embodiment. As regards the first  14 , second  16 , third  18  and fourth  22  surface portions this embodiment generally corresponds to that of  FIG. 1 . This also applies to the stripes of adhesive  24 , which are provided on the fourth surface portion  22 , the coating  20  of the third surface portion and the stripes of adhesive  26 , which are provided on the coating  20  and, partially, in the embodiment shown, on the first surface portion  14 . The embodiment of  FIG. 4  differs from that of  FIG. 1  because a fifth  28  and a sixth  30  surface portions are provided as heat seals. Moreover, a heat seal area indicated at  38  can be present adjacent the first  14  and second  16  surface portions, respectively. It should be noted that there can be a distance or spacing between one or both heat seal areas  38  and the first  14  and second  16  surface portions, respectively. Moreover, the heat seal areas  38  can also be present between the first and third and between the second and fourth surface portions. With the described heat seals, hermetic sealing of the final package can be realised. In other words, the package can be formed airtight and vapour proof, so that the final package is also suitable for products such as cheese or coffee, which require hermetic packages. It can be mentioned that the heat seal area  38  can also be provided as a lacquer on top of the adhesive or sealant of the first  14  and second  16  surface portions. When both heat seals and re-closable adhesives are provided, as in the embodiment of  FIG. 4 , a package can be provided, which is hermetically sealed in the original state, and which is re-closable after the first opening. It should also be mentioned that the heat seal features of the embodiment of  FIG. 4  can also be provided to the first and second embodiments described above, as well as the fourth embodiment, described below. In the embodiment of  FIG. 4 , the machine direction is indicated with arrow A and a web, extending in the direction A and constituting a plurality of substrates as shown in  FIG. 4 , can be used in a vertical packaging machine for producing packages in the form of bags or pouches. Such a bag will be described with reference to  FIG. 6  below. 
       FIG. 5  shows the substrate of  FIG. 4  in the fully opened state. In other words, the bag or pouch produced from the substrate of  FIG. 4  is fully opened, and all seals are broken in order to show the plan view corresponding to  FIG. 4 . As can be taken from  FIG. 5 , in a manner corresponding to that described above with reference to  FIGS. 1 and 2 , a part of the coating  20  of the third surface portion  18  has been removed so that coating free, stripes  36  are visible which indicate that the package has been opened and/or been tampered with. This function fully corresponds to that described above with reference to  FIGS. 1 and 2  and does not have to be repeated here. In particular, the modification of  FIG. 3  is also applicable to the embodiment of  FIGS. 4 and 5 . 
       FIG. 6  shows a perspective view of a bag  10  produced from the substrate of  FIG. 4 . In particular, the bag  10  is shown in an opened state and it can be seen that the orientation has been changed by 90 degrees relative to the orientation shown in  FIGS. 4 and 5 . In particular, during manufacture of the packaging material and/or the package, the heat seals of the fifth  28  and sixth  30  surface portions can be called end seals. However, in use, as can be taken from  FIG. 6 , these will constitute the sides of the bag  10 . The top is constituted by the first  14 , second  16 , third  18  and fourth  22  surface portion, comprising the tamper evidence features as described above. In particular, stripes of adhesive  24  covered with coating  20 , which has been removed from the third surface portion  18  are visible on the fourth surface portion  22 . As regards the bottom  40  of the bag  10 , this is formed in a way to create a stand-up bag by appropriately folding the substrate  12  during production of the bag. In particular, a fold line, which is substantially parallel to the machine direction A is created in approximately the centre of the substrate in order to produce the bottom shown at  40  in  FIG. 6 . In particular, the heat seals of the fifth  28  and sixth  30  surface portions have the shape of an inverted Y, which is produced by folding a centre portion of the substrate  12  inwards which is an upwards direction in the orientation of the bag  10  shown in  FIG. 6 . As regards further details of such a bag or pouch, as well as the manufacture thereof, reference can be made to the WO 03/080441 A1, the disclosure of which is incorporated herein by reference. 
       FIG. 7  shows a further embodiment of a substrate  12 , from which a package in the form of a bag can be produced. In this case, those surface portions providing the tamper evidence features are provided at an “end” of the substrate considering the machine direction A. At the sides and a second end of the substrate  12 , heat seal areas  42  are provided, which are sealed to themselves. In a sense, the substrate  12 , shown in  FIG. 7 , is folded about a line running through the centre of the substrate  12  parallel to the machine direction A. Moreover, as with the embodiment of  FIGS. 4 and 5 , a heat seal area  38  can be present adjacent the first  14  and second  16  surface portion. It should be noted that the first  14  and second  16  surface portions are in this embodiment continuous with each other. This also applies to the third  18  and fourth  22  surface portions. The heat seal area  36  can also be spaced from the area covered with adhesive constituting the first  14  and second  16  surface portions. Furthermore, the heat seal area  38  can also be present between the first and second surface portions, on the one hand, and the third and fourth surface portions, on the other hand. In this embodiment, the area constituting the first  14  and second  16  surface portions is essentially sealable to itself, with the left half of this area constituting the first surface portion  14 , and the right half constituting the second surface portion  16 . 
     In the embodiment of  FIG. 7 , the entire third  18  and fourth  22  surface portions are covered with a coating  20 . In the embodiment shown, two stripes  24  of adhesive are formed on the fourth surface portion  22 , and two corresponding stripes  26  are formed on the coating  20  of the third surface portion  18 . When the package is formed, the stripes  24  are at least partially brought into contact with the stripes  26 . Thus, when the package is opened, the coating is removed from the third surface portion  18 , as shown in  FIG. 8 . However, unless the bonding forces differ from each other, the coating could also be removed from the fourth surface portion  22 . As a further alternative, in the embodiment shown comprising two stripes  24  and  26 , one coating free stripe  36  can be present on the third surface portion  18 , and one coating free stripe  36  can be present on the fourth surface portion  22 . 
       FIG. 9  shows a package in the form of a bag  10 , which can be formed from the substrate shown in  FIG. 7 . The heat seal areas  42 , extending parallel to the machine direction A, constitute a side of the package and the heat seal area  42 , extending substantially perpendicular to the machine direction A, i.e. the above-mentioned second end seal constitutes the bottom  40  of the bag. The tamper evidence features are provided at the top of the package. In this context,  FIG. 9  shows a somewhat different embodiment with four stripes of adhesive  24 , which are covered with removed coating after first opening. Between the second and third stripe a gripping area  44  and a hole  46  for hanging the bag to a suitable carrier can be provided. As regards the embodiment of  FIGS. 7 to 9 , it can be mentioned that the fourth surface portion  22  does not have to be covered with coating entirely. Rather, only the area underneath the stripes  24  of adhesive and/or the surroundings thereof, can be covered with coating, in order to provide the tamper evidence feature, when the stripes of adhesive  26 , which are provided on the third surface portion, remove the stripes of adhesive  24  including the coating underneath from the fourth surface portion  22 . Finally, it should be mentioned that any features, which are mentioned with regard to a single or only some embodiments above, are applicable to all other embodiments as well.