Reclosable film package

Abstract: A reclosable film package (10) with a pack (15) of films wrapped in a light-tight bag with an exit flap (16) folded back on the stack and having a light-tight seal (17) near its free end, and a rectangular carton (11) made from a one-piece blank and having a top opening (12) closeable by means of a hinged top panel (13).

Description: BACKGROUND OF THE INVENTION 1. Field of the invention. The present invention relates to a reclosable film package for a stack of photographic film sheets, in particular for medical X-ray films. Description of the prior art. Medical X-ray film sheets that require a darkroom for their loading in an X-ray film cassette for their exposure, or in the magazine of a daylight loader for automatic reloading of a cassette as an image-wise exposed film has been removed therefrom, are packed in different forms. One package form comprises a stack of film sheets wrapped in a light-tight and moisture-tight bag that can be teared open in a controlled way. The bag is contained in a telescope-type carton comprising an inner carton in the form of an open rectangular holder and a two-part outer carton, the lower part being glued to the inner carton and the upper part forming a cover that telescopes over the protruding part of the inner carton. The described carton allows the light-tight storage of the film once the bag has been opened. Another package form comprises a stack of film sheets wrapped in a bag as described hereinbefore but contained in a one-piece carton, the top of which is delimitated by a weakened peripheral line so that it can easily be peeled away thereby to open the carton. Then the bag can be teared open to give access to the film sheets. This package can not be re-closed after opening, so that so-called "bins" are required, i.e. light-tight cabinets or slides for keeping the opened packages light-tight whilst the room is lit. The advantages of this package over the first type described are its simple and cheap manufacturing as the one-piece carton may be a wrap-around carton and its reduced environmental load as the empty package is discarded. SUMMARY OF THE INVENTION. Object of the invention. It is the object of the present invention to provide a single carton type film package that is economically to manufacture but that nevertheless is suited for keeping the film contents light-tight once the package has been opened. In accordance with the present invention, a reclosable film package comprises : a filmpack 15 formed by a stack of film sheets wrapped in a light-tight bag with a circumference substantially greater than the circumference of the film sheet stack whereby said bag has opposite side margins, said side margins being mutually folded toward one another on the pack, and with an exit extension in the form of a flap folded back on the pack on the side opposite to the side where the side margins of the stack have been folded, and having a peelable air- and light-tight seal near its free end, and a rectangular carton having a top opening closeable by means of a top panel hingedly connected to an edge of the top opening, which carton is provided with a weakened circumferential line enabling the controlled removal of a top portion from the carton. At first use of the package, the user opens the top panel and removes the film pack at least partly from the carton. He opens the light-tight seal and takes out the required number of film sheets from the bag for loading the film cassettes or film magazines. Then he folds back the flap thereby sealing the contents of the bag against light and re-inserts the bag into the carton to keep the flap backfolded. Then he closes the top panel for further improving the light-tightness of the contents. The carton of the inventive film package is preferably a one-piece wrap-around carton formed in situ around the film pack consisting of the stack of film sheets and their wrapping bag. To that end, an appropriately creased and cut blank may be used, comprising a rear panel having on opposite sides thereof side panels connected along fold lines, a bottom panel connected along fold lines with the rear and the front panel respectively and a top panel connected along a fold line with the rear panel. The described blank is placed on a transport belt or the like and the film pack is put on the rear panel. Next the top panel is folded against the filmpack, a locking flap of the top panel becoming located on the front side of the filmpack, and then the front panel is folded over the film pack whereby the bottom panel becomes applied against the bottom of the film pack and the locking flap of the top panel is clamped between the front panel and the film pack. Finally, the corresponding side panels are folded and adhesively bonded together. The finished package may receive a warranty sealing label on its top panel. Suitable features of the film package according to the invention are as follows. The light-tight seal of the filmbag is formed by a peelable heat-seal. This has the advantage that the seal may be opened without destruction of the flap so that this may be folded back for forming a light-tight seal again. The seal is located sufficiently inward of the peripheral edge of the bag opening to allow easy grasping of the margin of the flap for peeling open the seal. The peelable seal of the filmbag has a sawtooth-like form. This has the advantage that opening of the seal does not only occur in a transverse direction with respect to the seal, but also in a direction comprising a component running parallel therewith, so that a smooth opening of the seal with less effort is obtained. Since the top end of the carton is provided with a weakened circumferential line, controlled removal of a top portion of the carton is easy. The shell thus remaining has the advantage that it forms a handy holder for a film pack from which one or more films can be taken out rapidly without having to open the top panel and pull out the film pack to unfold the flap. The light-tightness of such wrapping is still guaranteed by the back-folded flap, but nevertheless the package should be handled with care since the second light-lock formed by the carton is missing. In another way, the film sheets can be taken out from the opened bag and placed in the remaining shell of the carton. This way of keeping the films greatly facilitates their accessibility but requires the use of a bin. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described hereinafter by way of example with reference to the accompanying drawings wherein : Fig. 1 is a perspective view of one embodiment of a film package according to the invention, Fig. 2 shows different phases in the wrapping of a stack of film sheets in a bag, Fig. 3 shows the preparation of the film pack for wrapping in a carton, and Fig. 4 shows the wrapping of the film pack. Detailed description of the invention. Fig. 1 shows diagrammatically one embodiment of a recloseable film package 10 according to the invention. Rectangular carton 11, represented in drawn lines, is made from a one-piece blank of corrugated paperboard and has a top opening 12 closeable by a top panel 13 with a locking flap 14. The top panel is hingedly connected to the edge 9 of opening 12 and has been shown in partly open position for the sake of clearness, and for the same reason the carton has been drafted as being transparent in order to show the wrapped film pack 15 in broken lines. The film pack consists of a light-tight bag with a flap-like extension 16 folded back on the pack as shown. The flap forms the exit of the bag and is light-tightly and air-tightly sealed by a sawtooth-like seal 17. A suitable material for the bag is a laminate consisting of the following layers in superposition : paper, aluminium and black peelable polyethylene. The carton is finally provided with a weakened circumferential line 18 for occasional removal of the upper portion of the carton. The assembling of the film package is described hereinafter. Figs. 2a to 2e show the first phase of the manufacturing, viz. the wrapping of a stack of the sheets in a bag. Fig. 2a shows very schematically how a stack 19 of X-ray film sheets and a stack 20 of empty wrapping bags 21 are located on their respective positions in a film wrapping machine. The wrapping bags may suitably have been formed by the folding of a sheet of wrapping material about its transverse axis and next the sealing of its lateral extremities to each other to form seals 23 and 24, see Fig. 2b that shows the dispensing of the upper bag from the stack to bring it in line with the longitudinal axis 25 of the film stack. Fig. 2c shows the opening of the bag by any means known in the art such as suction means, grippers, etc. The longitudinal marginal portions 26 and 27 of the bag inside of the seals 23 and 24 are kept clamped together so that an opened bag with almost rectangular cross-section is obtained. Fig. 2d shows the introduction of the film stack into the opened bag. The inner dimensions of the opened bag are such that the insertion of the film stack does not raise any problem. Fig. 2e shows the evacuation of the air from the bag in order to give it a low air content and to provoke score lines in that bag at the ciecumference of the stack, and next the airtight sealing of the free extending flap 16 according to a sawtooth-like pattern 17. The sealing is preferably done by means of heated sealing clamps having a sealing pattern as shown on the figure and causing the melting of the inside polyethylene layer of the bag. Seal 17 is located somewhat inward of the free edge of the bag, so that a free margin 28 with two coinciding plies of the bag is available that can be gripped for opening the package. The evacuation of the air from the film pack just formed causes the extending portions of the bag that surround the film stack at three sides to collapse thus forming two side flaps 29 and 30 that are wider than the flaps 26 and 27 and the closure flap 16. The folding of the flaps of the bag is described hereinafter with reference to Figs. 3a to f, Fig. 3a being an enlarged view of Fig. 2e. Referring to Fig. 3b, side flaps 29 and 30 are folded under the film pack whereby end configurations at the bottom of the pack are formed as shown in detail by the perspective view of the bottom end of flap 29. Fig. 3c shows the folding of the free extending end portion 31 of flap 29 against the bottom side 32 of the film pack whereas Fig. 3d shows the folding of the remaining free extending triangular portion 33 of flap 29 against the bottom of the film pack over flap portion 30. The folding of the portions of the side flaps 29, 30 at the location of the closure flap 16 occurs according to slightly tapering directions, see the folding of flap 30 in Fig. 3e, so that closure flap 16 finally obtains a slightly tapering configuration as shown in Fig. 3f. The means for carrying out the different folding operations described hereinbefore have neither been described, nor illustrated in the drawings since these means belong to the common knowledge in the packaging industry. The wrapping of the closed film pack in a wrap around carton is shown in Figs. 4a to d. Fig. 4a shows how a one-piece blank 34 is laterally fed in the direction of arrow 35 to lie in a position in which a film pack 15 can be placed on the blank, see Fig. 4b. The blank has a rear panel 38 having on opposite sides side panels 39, 40 connected along fold lines 41, 42, a front panel 43 having on opposite sides side panels 45, 46 connected along fold lines 47, 48, a bottom panel 49 connected along fold lines with the rear and front panel respectively and a top panel 13 connected along a fold line 9 with the rear panel and having a flap 14 for keeping it closed. Blank 34 is finally provided with weakened lines 51 and 52 that together will form the circumferential weakened line 18 of the completed container. Fig. 4c shows the folding of the rear panel 38 of the blank over the film pack 15, and Fig. 4d the folding of the top panel 13 together with the closure flap 16. Finally, corresponding side flaps of the blank are provided with a hot melt adhesive and next applied onto each other. The finished package looks as shown in Fig. 1. The closed carton is preferably provided with an identification label, and a sealing label joining the top and front panel 13 and 38. At first use of the package, the operator destroys the seal of the top panel in the darkroom, opens the top panel and partly withdraws the film pack from the carton through opening 12 to enable flap 16 to be folded open. He grips the free marginal portions 28 of the flap and progressively pulls open the seal 17. Then he can remove the cardboard panels from the top and the bottom of the film stack, if there are such panels, in order to give the film sheets more freedom in their wrapping and then he can take out the required number of film sheets. Thereafter the operator folds back flap 16 and reinserts the film pack in the carton thereby to keep the flap tightly clamped against the film pack. Closure of top panel 13 by means of closure flap 14 provides an extra seal against undesired exposure of the film sheets to environmental light. The package can now be stored in daylight conditions. Re-opening of the package for each successive loading operation of a cassette can be avoided if so-called bins are used in the darkroom. In that case the upper portion of the carton is removed by tearing it away along weakened line 18, so that in fact an open-ended box is obtained. The film pack is taken out, the bag is removed from the film stack and next the filmstack is re-introduced in the open-ended box for keeping the films together in the bin. The inventive filmpackage was manufactured for standard film formats measuring 13 x 18 cm up to 35 x 43 cm, for stacks comprising 100 non-interleaved X-ray films.

Claims: A reclosable film package (10) comprising : a filmpack (15) formed by a stack (19) of film sheets wrapped in a light-tight bag (21) with a circumference and a length substantially greater than the circumference and length of the film sheet stack whereby said bag has opposite side margins (29,30), said side margins being mutually folded toward one another on the pack, and with an exit extension in the form of a tubular flap (16) folded back on the pack on the side opposite to the side where the side margins of the stack have been folded, and having a peelable light-tight seal (17) near its free end, and a rectangular carton (11) having a top opening (12) closeable by means of a top panel (13) hingedly connected to an edge of the top opening, which carton is provided with a weakened circumeferential line (18) enabling the controlled removal of a top portion from the carton. A film package according to claim 1, wherein the seal (17) is located slightly inward of the free edge of the flap (16) of the bag (15) to allow grasping of the margin (28) of the flap for peeling open the seal. A film package according to claim 1 or 2, wherein said filmpack is a low-air content package.

Inventors: CORNELISSEN HERMAN LUDOVICUS, PEETERS DIRK, CORNELISSEN, HERMAN LUDOVICUS, PEETERS, DIRK
Applicants: AGFA GEVAERT NV, AGFA-GEVAERT NAAMLOZE VENNOOTSCHAP
Application year: 1991
Main classification: G03C3
IPC codes: B65D77, G03B42, G03C3