Patent Publication Number: US-2010108555-A1

Title: Packages and methods for use with stored items

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/781,383 filed on Jul. 23, 2007, which claims the benefit of Provisional Application Ser. No. 60/832,884 filed on Jul. 25, 2006. The entire contents of the listed prior applications are incorporated herein by reference. 
    
    
     FIELD 
     The present invention relates to a flexible package constructs and a method for indicating expiry status of foods, medicines, and other perishable products. More particularly, the invention relates to a package incorporating a slider assembly for opening it, and a lifetime indicator associated with the slider assembly. 
     BACKGROUND 
     Consumer awareness of product freshness has led to the widespread practice of addressing this issue by means of appropriate product labeling. Where relevant, the label will typically provide information related to the freshness and suggested storage method of the product. This information may include a date of manufacture, a “sell by” date, or a “best before” date. A “sell by” date specifies by which date the product should have been sold to the consumer. A “best before” date specifies by when the product should be disposed of by the vendor or consumer. 
     The recommended storage method typically specifies whether the product is to be stored in the refrigerator or freezer and whether this storage method is to be used from the time of purchase or from the time of first opening. The former method is typically used for dairy products, whereas the latter method is usually more appropriately for jams, sauces conserves and liquid medications. For some items the labeling will also specify for how long the product may be kept after it has first been opened. The reasoning behind this is that if the product is produced and packed under conditions that eliminate deterioration, such deterioration will only occur following this first opening. Alternatively, product deterioration may commence at manufacture, but be dramatically accelerated once it is exposed to air. In either case, it is important to monitor the time since opening and not just the marked shelf-life. 
     A number of products have been developed and commercialized that implement the concept of active labeling. These products contain a chemical system or liquid migration system which provides a color change over time, either as a function of elapsed time since activation, or by integrating time and temperature since activation. The latter are termed TTIs (time-temperature indicators) whereas the former primarily indicate the passage of time. Herein both types of indicators are referred to generically as “lifetime indicators” or simply “indicators”. The specifications of a TTI can be set to emulate those of the foodstuff in the package. Thus, given that the TTI is placed on the package and activated as the food is produced, the TTI gives an accurate indication of the food freshness which takes into account the vagaries of the distribution chain. In particular, if the product has not been maintained at the appropriate temperature through a part of the distribution chain, the TTI may give the consumer an indication thereof. 
     U.S. Pat. Nos. 4,292,916, 5,053,339 5,446,705 and 5,633,835 describe color changing devices for monitoring the shelf-life of perishable products. These devices are initiated by physically bringing into contact reactive layers so that the reaction will start, and this action can only conveniently be performed at the time of packaging. This approach is suitable for monitoring the degradation of foodstuffs which lose freshness throughout the entire distribution chain. U.S. Pat. No. 5,555,223 describes a process for attaching timing indicators to packaging, including the step of setting the timer clock at the exact time of production. 
     There is a substantial proportion of food and drug stuffs, and other perishables for which significant degradation starts to occur only when the package is opened. U.S. Pat. No. 6,373,786, issued on Apr. 16, 2002 and incorporated herein by reference, addresses this issue for rigid containers incorporating a rigid cap or closure. the &#39;786 patent describes the integration of a lifetime indicator into the cap or closure, such that the first opening of the cap activates the lifetime indicator. In this manner, the thus incorporated lifetime indicator will show the elapsed time or time-temperature integral since the container was first opened. However, while the &#39;786 patent provides a good solution for rigid containers such as bottles and cartons which have a closure, many types of foods, drugs and other perishables are packaged in at least partially flexible packaging such as plastic bags or shrink seal packages, and for these packages attaching the existing timers and TTIs is likely to produce misleading results in that they have no simple and foolproof means of activation at the time of opening the package. 
     It is therefore the intention of the present invention to obviate the shortcomings of the above-mentioned solutions by providing a simple and appropriate means of activating a lifetime indicator on an opening assembly of an at least partially flexible package for foodstuffs, medicines and other perishable products, and preferably those which have long shelf life but deteriorate after opening. Of course, the artisan will recognize that the teachings herein can be applied to any application in which it is desirable to indicate an elapsed time since opening a package such that the types of products or items mentioned herein are merely representative. 
     SUMMARY 
     Most packaged foodstuffs are clearly marked with a best buy or expiry date, and are often stable even well beyond these dates. However, certain foodstuffs, in particular meats and fish, deteriorate very rapidly after the initial opening. So while the expiry status of a packaged food product can be gauged by the date printed on the package before it is opened, its expiry status after opening is a different matter entirely. For example, according to United States Department of Agriculture (USDA) guidelines: hot dogs can be safely kept in an unopened package for 2 weeks but only for 1 week after opening; luncheon meats can be kept in an unopened package for 2 weeks but only 3-5 days after opening; and summer sausage marked “keep refrigerated” can be kept in an unopened package for 3 months but only for 3 weeks after opening (see: http://www.fsis.usda.gov/Fact Sheets/Refrigeration &amp; Food Safety/index.asp). Thus the expiry status of certain foods is strictly dependent on the time of opening, and therefore the present disclosure serves to indicate said expiry status as it relates to such foods once their packaging is opened. 
     The described embodiments preferable comprise an at least partially flexible sealed package comprising a flexible film and an opening assembly which serves to open said package. Said opening assembly incorporates a lifetime indicator to indicate product condition, such as the expiry status, or the conditions in which the product is stored, such as the time since the product was exposed to ambient air or the temperature that the product was exposed to. The arrangement is such that the opening action of said assembly serves to activate said lifetime indicator. Commercial lifetime indicators suitable for integration into certain described packaging arrangements include Timestrip® (Timestrip PLC, Hitchin, Herts, UK), VITSAB® (VITSAB AB, Malmö, Sweden), and MonitorMark™ (3M, St. Paul, Minn., USA); all of which may be activated by applying pressure to them. Further prior art includes U.S. Pat. No. 6,916,116 issued Jul. 12, 2005 which describes a similar indicator. The opening assembly may comprise either a single-use or a re-closeable mechanism. In a preferred embodiment of a re-closeable mechanism, said mechanism is a zipper or slider-type opening mechanism. In a further preferred embodiment, said slider or zipper is similar to that of a Ziploc® bag (SC Johnson, Inc., WI, USA), in that it can be repeatedly closed and re-closed by sliding. In a preferred embodiment of a non-re-closeable mechanism, said mechanism may be a knife-type opener (i.e., a blade) similar to the EasyCutter™ (Pliant Corp., Schaumburg, Ill., USA) which serves to cut off an edge of (or a sealed portion of) the package. 
     In a preferred embodiment, said lifetime indicator is integrated into the opening mechanism of said opening assembly of said at least partially flexible package such that the opening of said mechanism activates the indicator. 
     In a further preferred embodiment, said lifetime indicator is integrated into a sliding mechanism of said opening assembly of said at least partially flexible package such that the first sliding of such mechanism activates the indicator. 
     Also in preferred embodiments said lifetime indicator is either an elapsed time indicator or a time-temperature indicator (TTI), or a combination of the two. 
     In preferred embodiments said assembly comprises at least two parts movable relative to each other, said relative motion serving to apply pressure to said lifetime indicator or otherwise cause its activation. 
     Thus, there is preferably provided an at least partially flexible sealed package having an opening assembly, said opening assembly further comprising a sliding component and a lifetime indicator. The movement of said sliding component serves to open a seal of said package. The arrangement is such that movement of said sliding component activates said lifetime indicator due to the relative motion between said sliding component and at least part of said lifetime indicator, such that said lifetime indicator can thereby provide a visual indication of the expiry status of the product within said package from the time of opening onwards. Said sliding element is selected from the group including a sliding knife (or blade) and a zipper. Furthermore, said package may be re-closable, whether by use of the slider or due to any other closing mechanism such as snap-fit closures or adhesive. In certain arrangements the lifetime indicator may comprise a blister containing a liquid, such that the rupturing of said blister activates said lifetime indicator. Said lifetime indicator is selected from the group including elapsed time indicators and time-temperature indicators and combinations thereof. The expiry status shown by the lifetime indicator represents a measurement index selected from the group including elapsed time and time-temperature integrals and combinations thereof. The type of said package is selected from the group including plastic bags, vacuum packed packages and blister packages. Films used for such packages may range from oriented polypropylene (OPP), laminated films and high-density polyethylene (HDPE). 
     The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood. 
     With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1   a  is a perspective external view of an at least partially flexible film package according to a first exemplary embodiment; 
         FIG. 1   b  is an exploded, cut-away view of  FIG. 1   a;    
         FIGS. 1   c  and  1   d  show the opening of said package, wherein  FIG. 1  shows the package in a closed state and  FIG. 1   d  shows the package in an opened state; 
         FIG. 2   a  is a planar view of another exemplary embodiment of a package with a cross-section line marked on it; 
         FIG. 2   b  is a cross-sectional view of the package as seen about the cross-section line in  FIG. 2   a;    
         FIG. 3   a  is a planar view of another exemplary embodiment of a package with a cross-section line marked through said package&#39;s rider-base opening mechanism; 
         FIG. 3   b  is an isometric view of the jockey component of the package&#39;s rider-base opening mechanism; 
         FIG. 3   c  and  FIG. 3   d  are isometric view of two sides of the base component of rider-base opening mechanism; 
         FIG. 3   e  and  FIG. 3   f  are partial cross-sectional views through said rider-base opening mechanism, showing its closed (locked) state and its open (unlocked) state, respectively; 
         FIG. 4  is a cross-sectional view of another exemplary embodiment of a package where said package is filled with contents; 
         FIG. 5   a  is a front isometric view of another exemplary embodiment of a package, and showing the package in a closed, sealed state; 
         FIG. 5   b  is a front isometric view of the package of  FIG. 5   a  in an opened state; 
         FIG. 5   c  is a rear isometric view of the package prior to assembly of its lifetime indicator and sliding knife; 
         FIG. 5   d  is a bottom cross-sectional view of the package&#39;s sliding knife; 
         FIG. 5   e  is a side cross-sectional view of the package&#39;s sliding knife; 
         FIG. 6   a  is a top isometric view of a blister style package embodiment in a closed state; 
         FIG. 6   b  is a top isometric view of the blister style package in after its seal has been cut by a sliding knife; 
         FIG. 6   c  is a bottom isometric view of the blister style package shown in  FIG. 6   b;    
         FIG. 7   a  is an isometric view of an alternative construction for a lifetime indicator for use on an at least partially flexible package; 
         FIG. 7   b  is an exploded isometric view of the lifetime indicator; 
         FIG. 7   c  is an isometric view of a package incorporating the lifetime indicator, and showing the package in a closed state; 
         FIG. 7   d  is an enlarged isometric view of the package&#39;s opening assembly; 
         FIG. 7   e  is an isometric view of the package, and showing the package in an opened state; and 
         FIG. 7   f  is an enlarged view illustrating the lifetime indicator&#39;s tear away strip. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
       FIG. 1   a  shows a first exemplary embodiment of a package where said package comprises a storage compartment comprising a plastic bag  10  with an opening assembly  11  for opening and closing said bag  10 . In a preferred embodiment, said opening assembly  11  comprises an actuator in the form of a slider  12 , sealing lips  18  which serve to seal the bag  10 , and a lifetime indicator  13 . Suitable lifetime indicators for inclusion in said package include any which can be activated by relative motion of the slider  12  and the lifetime indicator  13 , such that the opening of the package causes the activation of said indicator. Referring now to  FIG. 1   b , an enlargement of the opening assembly  11  is shown, showing the details of a preferred embodiment of a lifetime indicator  13 . Said indicator  13  comprises a liquid filled blister  14  and a scale  15  showing elapsed time since activation of said indicator  13 . Examples of suitable lifetime indicators that can be activated in this manner include Timestrip® (Timestrip PLC, Hitchin, Herts, UK), VITSAB® (VITSAB AB, Malmö, Sweden), and MonitorMark™ (3M, St. Paul, Minn., USA). Referring now to  FIG. 1   c  and  FIG. 1   d , the location of the slider  12  before and after opening the package is shown. Note that, as the location of the slider  12  in  FIG. 1   c  is directly to the left of the indicator  13 , opening said package requires that the slider  12  must depress said blister  14  in order to traverse the indicator  13  and proceed toward the other side of the opening assembly  11 . Said squeezing action activates the indicator  13  such the indicator is activated by this opening action of the package. As is the general manner in such zip or slider packages, the traversal of the slider  12  across the opening assembly  11  causes the sealing lips  18  to part into an open lip section  19  as shown in  FIG. 1   d , and this is the way in which the specific embodiment shown is opened.  FIG. 1   d  also shows the blister  14  in its compressed or collapsed state, in which at least part of its liquid contents have been forced into other portions of the lifetime indicator  13  in order to activate the indicator. 
     Referring now to  FIG. 2 , a further preferred embodiment of the package of the present invention is shown in which the blister  14  is concealed when the package is closed. Advantageously, this embodiment prevents both accidental activation and deliberate tampering whereby people press the blister while leaving the product on the shelf.  FIG. 2   a  shows the package in its closed state where it can be seen that the blister section  14  of the lifetime indicator  13  is concealed behind the slider  12 .  FIG. 2   b  provides a cross-sectional view of the slider  12  along the line marked. This view shows two protrusions  17  into the interior space of the slider  12 . As the slider  12  is moved relative to the lifetime indicator  13  from a pre-opening position toward a post-opening position, these protrusions serve to depress the blister  14 , creating a situation that the package cannot be opened without said squeezing action occurring. 
     The lifetime indicator&#39;s strip  13  can be a prefabricated item that is introduced to the bag either by adhering or welding. In another embodiment the indicator  13  is integral to the package and the film provides one of the walls of the indicator. In this case the graphic area location is less limited and the indication fluid can be channeled to any location on the bag. 
     Referring now to  FIG. 3 , a further embodiment is demonstrated in which the indicator  13  is located on the slider assembly  12 . Advantageously, having the indicator as part of the slider obviates several changes on the manufacturing line of the flexible film package as this combined slider/indicator can simply replace a regular slider. Thus, according to this preferred embodiment, the slider assembly  12  comprises two parts: a base  31  and a jockey  30 . Said jockey  30  incorporates the features (not shown) that are responsible for opening and sealing the package  10  as said jockey  31  is moved from one side to the other of the opening assembly  11 .  FIG. 3   b  shows an enlarged isometric view of said jockey  30 , showing the locations of the lifetime indicator  13  within, and its component parts the blister  14  and the scale  15 .  FIG. 3   c  and  FIG. 3   d  show the two sides of the base  31 .  FIG. 3   c  shows the side of this base  31  which incorporates an elevated surface  32  with an inclined ramp reaching that elevated surface. Said elevated surface  32  serves to depress the blister  14  in the indicator  13  upon relative motion between the base  31  and the jockey  30 .  FIG. 3   d  shows the other side of the base  31 , which incorporates a rocker arm  34  rotating on a pivot  35 , said pivot  35  preferably being an integral molded feature of the base  31  and thus having the tendency to remain in a particular position. One tip of said rocker arm  34  ends with an elevated section  36  which is connected to the arm surface by an inclined ramp  35 . Said rocker arm  34  serves as part of the locking mechanism by which the base  31  engages with the jockey  30  as described below. 
       FIG. 3   e  and  FIG. 3   f  provide a partial section views of the combined base  31  and jockey  30  assembly shown in  FIG. 3   a .  FIG. 3   a  shows this assembly in a pre-opening or locked position, wherein the lifetime indicator is in a pre-activation state.  FIG. 3   f  shows the combined base  31  and jockey assembly  30  in a post-opening position, wherein the lifetime indicator is an activated state. These views expose the internal side of the rocker arm  34 , showing an array of teeth  38  located on the opposite end of said arm  34  relative to the elevated section  36 .  FIG. 3   e  shows said teeth  38  leaning against the bag  10 , thereby preventing the base  31  from moving and opening the bag. The rocker arm  34  is maintained in this position due to its tendency to remain in its molding position. Referring now to  FIG. 3   f , the state in which the jockey  30  is slid to the left relative to the base  31  is shown. In this state, the blister  14  of the indicator  13  is depressed by the elevated ramp  32  of the base  31 , followed by the deflection of the rocker arm  34  as its elevated section  36  engages into a recess in the protrusion  39  in a manner that the base  31  and jockey  30  can no longer be released from each other. Said deflection of the rocker arm  34  causes the teeth  38  of the rocker arm  34  to move away from the bag  10 , enabling the entire assembly formed by the thus engaged base  31  and jockey  30  to be freely moved from side to side across the top of the package. Note that, as per the previously described embodiments, the depression of the blister  14  during such engagement action ensures that the lifetime indicator  13  is activated as the package is opened, whereby the lifetime indicator can provide an indication of expiry status of a product from a time of opening onwards. 
     While the relative motion between the base  31  and the jockey  30  shown here is a linear sliding action, it will obvious to one skilled in the art the desired result can be achieved by other forms of relative action between these two parts including flipping, swiveling, rotating, bending, folding, pressing one into the other, etc. Furthermore, it will be obvious to one skilled in the art that the jockey  30  and the base  31  can be fabricated as a single part. The key element is that the opening action of the package requires the depression of the blister  14 , and the specific action depressing this blister  14  can be a swiveling action, a linear action, rotation or any other. It will be obvious to one skilled in the art that a similar mechanism can be implemented in embodiments where the lifetime indicator  13  is part of or is attached to the bag  10  as shown in  FIG. 1  and  FIG. 2 . 
       FIG. 4  shows another preferred embodiment where the package  10  has a formed shape adopted to accommodate contents  42 . The contents  42  are shown as slices of food products such as meat or cheese. Alternatively the content may be any product or products of which monitoring the time from opening of the package may be a valuable or desired information, including pharmaceutical products, vaccines, diagnostic kits or components thereof, adhesives, living organisms, chemical products, biological products, etc. 
     The walls of the package may be formed by one or more of the methods known in the art including thermoforming, cold forming, heat shrink, injection molding, blow molding, or combination of such. A backing  41  is inserted into package  10  to support the product and/or to present information through at least partially clear wall. 
     Referring now to  FIG. 5 , a further preferred embodiment of a package is shown in which a cutting action is used to open the package.  FIG. 5   a  shows a preferred embodiment comprising a flexible bag section  10  and an opening assembly  11 , said opening assembly  11  further comprising a removable strip  50 , a permanent strip  54 , a lifetime indicator  13  and an actuator in the form of a sliding knife  55  having a blade  56 . The arrangement is such that the movement of said sliding knife  55  across the opening assembly  11  from a first position toward a second position trims-off the removable strip  50  from the permanent strip  54 . As the sealing/welding line  52  passes within said removable strip  50 , the cutting off of said removable strip  50  opens the seal on the package. Additionally, the movement of the sliding knife  55  over the lifetime indicator  13  from the pre-opening position toward the post opening position activates said indicator  13  as per the descriptions associated with the previous figures, such that the opening of the seal on the package activates the lifetime indicator. The permanent strip  54  can serve to guide the line of the sliding knife  55 . In a further preferred embodiment, guiding features may be formed in one or more of the package walls, eliminating the need for permanent strip  54 .  FIG. 5   b  shows the package after opening, where it can be seen that the blister  14  on the lifetime indicator  13  has been depressed. As will be obvious to one skilled in the art, said package may further comprise sealing lips  18  for manual snapping open and closed as shown in  FIG. 5   a  and  FIG. 5   b ; or such sealing lips  18  may not be included (as per  FIG. 5   c ).  FIG. 5   c  illustrates the sealed package of  FIGS. 5   a  and  5   b  prior to assembly of the indicator  13  and the sliding knife  55 , in order to emphasize the sealing line pattern  52  which encloses the area for locating the sliding knife  55  prior to opening. 
     Referring now to  FIG. 5   d  and  FIG. 5   e , bottom and side views, respectively, of the sliding knife  55  are shown, showing the internal cutting edge  56 . An example of such a sliding knife  55  is the EasyCutter™ (Pliant Corp., Schaumburg, Ill., USA), but it will be obvious to one skilled in the art that the cutting edge  56  incorporated in the sliding knife  55  can be of any fashion known in the art including rolling blade, shearing element, sawing element, etc. Said sliding knife  55  can be made in one piece from extremely rigid molded plastic such as crystal polystyrene, or over molding of plastic material on a metal blade. Said sliding knife  50  will be engaged with the bag  10  in a form that the slider can not be removed until a complete opening of the bag. 
     Referring now to  FIG. 6 , a preferred blister configuration of a package is shown. Said package comprises a container  60  which may be flexible, semi-flexible or rigid; a flexible foil closure  61 ; and an opening assembly  11  further incorporating a sliding knife  55 . A sealing portion  62  of said foil closure  61  is welded or adhered around the flange of said container  60 , such that the container  60  intended to only be opened from a defined flap  63 . In a preferred embodiment of said package, said flap  63  cannot be lifted to start the opening action as long as the edge  64  of said container  60  remains in position. Said edge  64  is the area of said flexible foil closure  61  which is firmly attached to the container flange. As such, the flap  63  is initially inaccessible because edge  64  prevents finger grip of the free flap  63  and thus prevents pulling open the closure  61 . The sealing method of the sealing portion  62  can be of the type that allows a single opening, or may permit multiple opening and resealing. As described in connection with  FIG. 5  above, a sliding knife  55  serves to open the package by cutting off this edge  64  as said sliding knife is moved across the opening assembly  11 . Said opening assembly  11  and cutting line maybe straight (as shown) or be curved. Said opening assembly  11  further incorporates a lifetime indicator (shown in  FIG. 6   c ), the arrangement being such that the movement of the sliding knife  55  across said opening assembly  11  from a first position toward a second position causes the relative motion between the sliding knife  55  and the lifetime indicator  13  which activates said indicator  13 . Said indicator  13  can be adhered to the package or constitute an integral part thereof. In a further preferred embodiment, said indicator  13  is protected from accidental activation by the sliding knife  55 . In a further preferred embodiment, at least part of said indicator is viewable from the top of the package, whether via a transparent section thereof or otherwise. 
     Referring now to  FIG. 6   b , the package is shown in the state where the edge  64  has been removed such that the flap  63  is released for pulling. The completion of the opening action then entails the lifting of said flap  63  until the foil closure  61  exposes the package&#39;s contents. In a further preferred embodiment, the sliding knife  55  and the container are designed such that said sliding knife  55  remains on the package after opening. 
       FIG. 7  shows a further preferred embodiment incorporating a different fashion of indicator  71 .  FIG. 7   a  shows the indicator  71  in a pre-activation state. The indicator comprises a body  71  with an indication area  72 , and a removable portion  73  in a form of a strip. The strip further comprises a scoring line and a tab  74  extending beyond the scoring line. 
       FIG. 7   b  shows the indicator  71  after activation. The activation is accomplished by a relative motion between the strip  73  and the body of the indicator  71 . In one embodiment of the indicator the time indication is a visual color change of the indication area  72  caused by chemical reaction of a first substance that is present in a first the layer of the indication area  72  with a second substance that present in a second layer behind the indication area  72 . Said two layers are separated by the strip  73  until the activation time which prevents interaction between the two layers. Once the strip is removed the two layers come in contact and the chemical reaction begins which gradually changes the color of the indication area  72 , providing information about the elapsed time since activation. Other color changing interaction, or combination of interactions, can be implemented between the two layers including diffusion of a substance, or biological activity. In other embodiments the interaction of a substance in the indication layer is with a substance in the ambient such as oxygen or moisture which the strip prevents from reaching said substance before activation. The strip  72  can be made from various materials including a plastic film or a foil. 
       FIG. 7   c  and the enlarged detail  7   d  show the indicator  71  integrated with a bag  10  which has a sliding opening, in a pre-opening state. The indicator body  71  is integrated with the slider  76 , and the tab  74  is attached to the edge of the bag  10 , thus the indicator is maintained in a pre-activation state. The indication area  72  is shown through an opening in the slider  72 . 
     Referring to  FIG. 7   e , the bag  10  is shown in the opened state where the slider is moved to the opposite end of the opening edge  13 . As a result of the relative motion between the slider and the bag, a relative motion between the indicator body  71  and the strip  73  resulting in activation of the indicator as illustrated in  FIGS. 7   a  and  7   b.    
       FIG. 7   f  shows that optionally, after opening the package  10 , the strip  73  can be torn off along the score line  74  and be discarded. The strip  73  may include information about the product or information for participation in a promotional activity of the product. In one embodiment the strip provides a key of index which facilitates the user reading or interpreting information in the indication window. Such information can be posted in other areas of the package  10 . 
     It will be obvious to those skilled in the art that the indicator  71  can be accommodated with the package  10  in various forms including one where the indicator body is integrated with the bag  10  and the strip is attached to the slider  76 . 
     In addition it will be obvious to one skilled in the art that the any of the above-described packages can further incorporate a tamper-evident feature, such that the action of opening the opening assembly  11  results in a visual non-reversible mechanical change in one or more of the parts. 
     It will thus be appreciated from the present disclosure that a simple and inexpensive means of providing an at least partially flexible film package that shows a product lifetime indication based on the elapsed time or time-temperature integral since first opening of the container is provided. 
     It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.