RECLOSABLE BOX LINER

Abstract: A reclosable plastic box liner (30) having a reclosable fastener (40) of a length relatively the same as that of the width (X) of the box when the liner (30) is filled with products such as cereals, crackers or chips. To achieve a liner (30) having sufficient size to fill the box, yet, having a reclosable fastener (40) of a correct length, the top section of the liner is cropped or chamfered at its ends (36, 38) generally above the product fill level (43) of the liner. Preferably, the chamfered section (36, 38) is angled from the vertical at least from the product fill level (43) to the reclosable fastener (40).

Description: The present invention resides in a package comprising a reclosable bag or liner for a box. More particularly, the present invention resides in a liner which is provided with a reclosable fastener having a width which is approximately the width of the box and is readily openable and reclosable at any reachable height within or outside of the box. There has been a long-felt need for a package for storing a food product such as, for example, a cereal product, crackers, cookies, and the like, in which the product is protected from contamination and moisture in the atmosphere but which is readily openable and reclosable so that when the package is opened and only a portion of the contents is removed, the remainder can be conveniently resealed and the content saved for future use. Most such packages presently comprise a box with a bag type liner which must be ruptured permanently or in which the flanges provided on the liner are permanently separated to gain access to the content. It is next to impossible, however, to effectively reseal the package. Consumers generally either roll-up the bag or liner to close the open top of the bag as best as they can or, alternatively, force the top of the bag back into the box and close a loosely interlocking flap at the top of the box. Neither of these methods fully reseal the bag or adequately protect the contents from the surrounding environment. A reclosable fastener, such as that usable with the bag or liner of this invention, can be that shown, for example, in British Patent No. 2,133,462, in which a male fastener provided with ribs on either side thereof is moveable into an interlocking relationship with a female fastener. Using a reclosable bag, such as that described in the before-identified British Patent, by placing it in a box to serve as a liner still does not provide a fully satisfactory package. When the bag or liner is filled with a product, the reclosable fastener, which is relatively stiffer than the film of the bag body, ends up being wider than the box in which it is contained. This naturally occurs with a generally rectangular shaped and unfilled flat bag that is subsequently filled and made to conform to a three dimensional shape, such as a box. Since the reclosable fastener section of the liner is wider than the box, when an attempt is made to push the fastener section into the box, it must be pushed together laterally. This can result in the fastener section being accordioned or crimped so that it is not readily openable. To be readily openable would require that the reclosable fastener section be raised again, taken from the box from where it has been stuffed, spread lengthwise to a width wider than that of the box, and then unzipped or otherwise unfastened. It would then be reclosed before stuffing the fastener section back into the box. Beside requiring more material than is necessary to form the liner, the above procedure results in an inconvenient closure which is essentially nonfunctional when it is below the top opening of the box in which it is contained. Prior to this invention there was thus the need to have a reclosable box liner which has a reclosable fastener of about the same width as the width of the box so that it would fit comfortably therewithin, avoiding wasted material, and even being openable and reclosable within the box below the open top of the box should that be desired, or in any other position as may be desired. With the width of the reclosable fastener so designed, the reclosable top of the liner is more easily rolled back into the box and will be correctly located in the box rather than being forced sideways or in some other awkward position when the relatively stiff reclosable fastener is too wide. Accordingly, the reclosable fastener of the invention will be more attractive and will be more readily openable and reclosable at any desired reachable height within the box or out of the box. The proper and desired width of the reclosable fastener is achieved by providing cropped-like ends or ears at and adjacent the extremities of the reclosable fastener, preferably with a predetermined seal angle. Generally, the angle of the seal of the cropped ears forms a chamfered section preferably running from the product level within a filled liner to the reclosable fastener level. A process to calculate a desirable seal angle has also been discovered. By employing the concept of this invention, a liner for a box which is easily openable and readily reclosable, and convenient to be rolled back into the box, has been provided. More particularly, the present invention resides in a liner adapted to be placed in a generally rectangularly shaped box said liner comprising a pair of side panels having side portions connected along side seals, a closed bottom portion, an open top, and a reclosable fastener extending across the open top of the liner, the side seals of the liner being continuous from the bottom portion to the ends of the reclosable fastener characterised in that the width of the bottom portion of the liner is greater than the width of the open top of the line and said seals having a chamfered section extending from the ends of the reclosable fastener towards the bottom portion of the liner so as to form a width transition zone adjacent the ends of the reclosable fastener. The present invention also resides in a process of forming a liner with a reclosable fastener, side walls and side seals for a box, which liner when empty has a width wider than the box in which said liner is to be placed, but said liner when filled with product has a width substantially the same as that of the box in which said liner is placed, characterized by the steps of determining a product level within the liner when filled and forming the side seals such that the chamfers extend from about said product level to at least said reclosable fastener, said chamfering being from a width generally about the same as the bottom of the bag at about the product level to generally about the width of the box at the reclosable fastener. Figure 1 is a schematic elevational view of a prior art reclosable bag in the unfilled state; Figure 2 is an isometric view showing the bag of Figure 1 filled with a product; Figure 3 is a schematic elevational view of the bag or liner of the present invention in the unfilled stage; Figure 4 is an isometric view of the bag or liner of Figure 3 filled with a product; Figure 5 is an isometric view of a box in which the bag or liner of Figure 3 is to be placed; Figure 6 is a cross-sectional elevational view of a bag such as shown in Figure 1, with dimensional notations; Figure 7 is a cross-sectional plan view of the box of Figure 5 with a bag of Figure 6 inserted therein as a liner, with dimensional notations; Figure 8 is a schematic elevational view of the bag liner of Figure 6 as it projects from the top of the box of Figure 5 when filled and located; Figure 9 is the liner of the present invention in its empty state; and Figure 10 is a schematic elevational view of the liner of the present invention when filled and located on the box of Figure 5. Referring more particularly to Figure 1, there is shown a prior art bag such as that taught in British Patent No. 2,133,462. The bag 10 has straight side seals 12 and 14, a closed bottom 16, an open top 18, and a reclosable fastener 20 extending across the bag adjacent the open top 18 of the bag. Figure 2 shows the bag of Figure 1 filled with a product 22 which causes the front and rear panels 24 and 25 to bulge outwardly, causing a spreading of the sides 28 and 29 including side seals 12 and 14. However, the reclosable fastener 20 maintains essentially its same configuration whether the bag is filled or empty and causes a depression thereunder as indicated by the angular disposition of the top parts 26 and 28 of the sides 28 and 29, respectively, which are essentially mirror images of each other. Thus, the width W1 of the bag 10 when filled between the sides 28 and 29 is less than the width W2 between ends 31 and 33 of the reclosable fastener 20. Differentiating from the bag 10 of Figures 1 and 2, is the bag or liner 30 of the present invention shown empty in Figure 3 and filled with product in Figure 4. Side seals 32 and 34 of the bag of Figure 3 are chamfered at its top section along edges 36 and 38 so that the length W3 of a reclosable fastener 40 between its ends 39 and 41 is less than the width W4 of bottom 44 of the bag when the bag or liner is empty. However, when the liner or bag 30 is full of product 22, the width of the bag W5 is the same as the width W6 of the top of the bag 42 and the length of reclosable fastener 40 which equals W3. Sides 37 and 45 are formed when the liner or bag 30 is filled and ideally are generally aligned with the ends 39 and 41, respectively, of the reclosable fastener 40. The seals 32 and 34 are therefor relatively straight seals extending all the way to the top 42 of bag 30, or at least to the reclosable fastener 40. To achieve this, it is preferred that cropped-like ends 36 and 38 of the bag 40 are formed as angular seals extending approximately from the anticipated product level fill point 43 to the ends 39 and 41 of the reclosable fastener. While other than a straight line between the fill point 43 and ends 39 and 41 of the fastener may be possible, a straight line would appear preferable as it forms the shortest distance between the two points. This angular disposition has been found to be functionally quite satisfactory. In order to fabricate a liner or bag having a reclosable fastener which will be about the same length as the width of a box in which the bag or liner is located when filled, it was discovered that a process could be followed to determine preferred embodiments for various boxes are more clearly described below with respect to Figures 4 and 9. Taking a box 44 such as shown in Figure 5 in which a liner is to be inserted, which box can have a typical interlocking top with flaps 47 and 49 with a tongue and slot interlock, the box 44 could have its width defined as the dimension X, its height defined as the dimension Y and its depth defined as the dimension Z. Such a typical box could contain a liner which can comprise a reclosable bag 46 having a reclosable fastener 48, a top 50, a foldable bottom 52 and side seals 54 and 56. This liner when unfilled, would have a width represented by reference A, and a height represented by reference B. When the liner 46 is inserted into the box 44 and filled with a product 22, the liner takes the shape of the interior of the box, and the side seals 54 and 56 fold against the ends 60 and 62 of the box. The box 44 essentially determines the liner height and width as a function of the box dimensions, i.e., the liner width A is equal to two times the seal width T (Figure 6) of the liner 46 plus one-half Z plus X plus one-half Z. If the liner 46 with the dimensions A and B is then inserted into the box 44 with the dimensions X, Y and Z, the liner will essentially take the shape of the box as shown in Figure 7, and reclosable fastener 48 will be longer (length W7 in Figure 6) than the width X of the box by the distance Z, which is equivalent to the two dimensions Z/2 or ½Z as shown more clearly in Figure 8. Since the reclosable fastener 48 is longer than the width X of the box, it is awkward to fold down that portion of the bag liner containing the reclosable fastener 48 into the box, and crimping or bunching up of the top of the liner containing the reclosable fastener is necessary to stuff the top of the liner into the box. Referring now more particularly to Figures 9 and 10, an unfilled liner 64 made according to the principles of this invention has side seals 66 and 68 which are essentially vertical from bottom 82 and then angled inwardly at about the level where the top of the product will be located in a bag when filled, to form side seal portions 70 and 72 which portions are angularly disposed until they generally reach reclosable fastener 74. Thereafter the side seals extend generally vertically upwardly as side seal portions 76 and 78 until the top 80 of the bag 64 is reached. The bottom 82 of the bag has a dimensions A, which is equivalent to the dimension A of the liner 46 of Figure 6, but it has its top width and that of the reclosable fastener 74 essentially equivalent to the width X of the box of Figure 5 as indicated on Figure 9. Dimension X is therefore A minus Z over 2 (½Z) minus Z over 2 (½Z), which is the actual minimal horizontal width of the cutaway section 70/76 and 72/78 from the regular side seal dimensions defined by the side seals 66 and 68. Reference P represents the height of the product in the liner and reference ϑ represents the angle seal portion 70 makes downwardly from the vertical. When the liner 64 is inserted into the box 44, it can be seen that the width of the entire bag, including the reclosable fastener 74 and bag top 80 is essentially the same as the width X of the box so as to provide the hereinbefore stated advantages of the present invention. The bag liner top and reclosable fastener can be readily opened and reclosed whether it remains below the top of the box where it can be reached as well as if lifted above the top of the box, and the top and reclosable fastener section of the liner does not have to be crimped or bunched to get that section of the bag liner into the box, as can be seen in Figure 10. With such a configuration as described generally above, it can be seen that a reclosable liner for a box can be achieved so that an advantageous, easy to use box liner can be produced. However, while certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes in applications and configurations can be made therein without departing from the scope of the invention. For example, various resins can be used in forming the liner of the invention. The liner may be multi-layered or mono-layered; the reclosable fasteners can be of various configurations; the liner can be sold as a package itself without being in a box; the box can be of different proportions; the reclosable fasteners can be formed with or separate from the liner, and the like.

Claims: A liner (30) adapted to be placed in a generally rectangularly shaped box (44), said liner comprising a pair of side panels having side portions connected along side seals (32,34), a closed bottom portion, an open top, and a reclosable fastener extending across the open top of the liner, the side seals of the liner being continuous from the bottom portion to the ends of the reclosable fastener characterised in that the width (W4) of the bottom portion of the liner is greater than the width (W3) of the open top of the liner and said side seals having a chamfered section (36,38) extending from the ends of the reclosable fastener towards the bottom portion of the liner so as to form a width transition zone adjacent the ends of the reclosable fastener. The liner of Claim 1, wherein the side edges (76) of the liner above the reclosable fastener are in the same angular direction as the side edges (32, 35) below the chamfered section of the transition zone. A liner as claimed in Claim 1 or Claim 2 characterised in that it is filled with a volume of a product sufficient to fill the liner substantially to the level of the start of said transition zone. The combination of a liner as claimed in Claim 1 or Claim 2 with a generally rectangular box for holding the liner wherein the top width (W3) of the liner is generally about the same as the width (X) of the box. The combination of Claim 4, wherein the width of the liner in the lower part thereof is such as substantially to fill the box when the liner is filled with a product. A process for forming a liner according to Claim 1 for the combination of Claim 4 comprising the steps of determining a product level within the liner when filled and forming the said side seals (32, 34) such that the chamfers (38, 36) extend from about said product level to at least said reclosable fastener (40), said chamfering being from a width (W4) generally about the same as the bottom of the liner at about the product level to generally about the width (W3) at the reclosable fastener.

Inventors: ZIEKE, LARRY M.
Applicants: THE DOW CHEMICAL COMPANY
Application year: 1987
Main classification: B65D5
IPC codes: B65D5, B31B7