CA1062209A - Package for a stack of sheet materials - Google Patents

Abstract

Abstract of the Disclosure A package for packaging a stack of articles in sheet form comprises at least two strips which are overlappingly sealed to each other, so forming a loosely overlying edge which greatly facilitates opening of the package. The whole may be provided with protective sheets at both sides of the stack, whereby said protective sheets may have a row of perforations at the edge of the composing strips so that the first sheet of the stack may easily be taken from the stack after removing part of the protective sheets.

Description

- 106ZZ()9 This invention is concerned with a package, and more pal~ticularly with a package intended for containing a stack of sheet materials. The invention reveals itself extremely well suited for containing a stack of sensitized films in face to face relationship, although any stack of sheet materials and, if necessary, even individual sheets may be contained in a package according to the invention.
Compared to the prior art packages, the package according to the inYention has significant advantages, whereof the feature of easy opening is one of great importance.
Moreover, the package may be easily manufactured and contributes positively to a clean aspect when being definit-ely open.
The prior art packages, for example t~e one described in Belgian Patent Specification 774,378 filed October 22, 1971 by Agfa-Gevaert N.V. wherein use is made of a tear-strip provided at the inner side of the package~ suffer from a first drawback in that the exact positioning of said tear-strip in the package and the punching of said strip through the latter at well defined distances requires very complicate packaging-apparatus.
~ he second drawback is noticed at the moment of use, that is to say, when the package is opened by means of tearing said strip. In that case, the latter becomes the cause that uneven and frayed edges are formed which give rise to an untidy appearance of the whole.

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lOf~Z209 It is an obJect of the invention to provide a package which does not posscss tllc foregoing dlsadvall~agcs.
~ ccording to the present invention there is provided a package for a stack of sheet materials wllicll is adapted to be openecl at one end to leave a defined edge around said opening, which package comprises a first tubular wrapping of sealsble material enclosing a major portion of said stack around its sides and one end and terminating adjacent the opposite stack end along a defined edge, a second tubular wrapping extending in at least partial over-lapping telescoping relation to said first tubular wrapping with its free end edge spaced from said defined edge of said first wrapping to constitute a skirt-like lower section, said first and second tubular wrappings being detachably sealed together around their contiguous periphery along a locus spaced from the free end edge of said second wrapping and leaving said lower skirt portion free for manual engagement to remove said second tubular wrapping bodily along said seal, leaving the stack within said first wrapping with its defined edge opening, and said sealed wrappings being uniformly tensioned around the stack periphery in its lengthwise direction, so that the stack is tightly contained :~
therein.
As will hereafter be explained each or either of the first and second tubular wrappings referred to in the foregoing definition may itself be a composite tubular wrapping formed by two or more narrower tubular wrappings of material sealed together in marginally overlapping relationship. Accordingly the invention includes any package comprising a stack of sheets in an enveloping wrapper, said wrapper comprising tubular wrappings of material sealed together in marginally overlapping relationship and forming a tube .- . : . . . ~ :

.-. . . - . : . , 106'~Z09 witllin which thc stack is located, the ends of the tube having been sealed up so that the stack is totally enclosed, there being, across opposite faces of the stack, marginal portions belonging to one or more of said tubular wrappings, which are free, i.e. unattached to the wlderlying wrapping portions which they overlap, so that a section of the wrapper, enclosing a part of the stack, may be removed by pulling on said free marginal portions~
to break the seals between that section of the wrapper and the remainder of it.
The scope and spirit of the invention will best be exemplified by a description of a preferred embodiment and in the light of the accompanying drawings, in which:
fig. 1 is a cross-sectional view of a package according to the invention;
fig. 2 is an enlarged view of fig. 1 in order to show the seals between the composing tubular wrappings;
fig. 3a and 3b show details of the protective sheets of the stack to be packed;
fig. 4 is an isometric view of a combined package enclosing a package according to the invention;
fig. 5 shows a longitudinal cross-section of another package according to the invention;

-fig. 6 is a longitudinal cross-section of still another package acoording to the invention;
fig. 7 is a transversal cross-section of the packages of fig. 1, 5 and 6;
figs. 8a and 8b show an elementary apparatus for packing a stack of sheet materials in a package according to fig. 6.

According to ~ig. 1, a package 10 is provided, intended for containing a stack of sheet materials 11. Optionally, but not necessary, is the provision of a pair of protective covers 12 and 13, one cover situated at each side of the stack 11 and overlapping the sheets contained in said stack.
The stack is hermetically sealed by means of a wrap, comprising the tubular wrappings 14, 15, 16 and 17. Said wrappings are made of materials which can be sealed together. This sealing may be carried out by glueing, heat sealing or any other technique known in the art. In the case that the-wrap has to contain sheets of light-sensitive material, such as photographic sheet films, the constituting materials must-be light- and mo~sture proof and be capable of pro-tecting the contained sheets against chemical vapours. A
paper-, aluminium-polyethylene laminate suits this purpose very well. Moreover, by the fact that this material is easily heat sea1able, automi~ing the packaging process =ay he ~`

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10~i2Z09 carried out with appratus which is rather simply in design. At the front side of the stack 11 are positioned a first broad tubular wrapping 14 and a first narrow tubular wrapping 15 whlch are over-lappingly secured to each other with the help of a seal 18 (see also fig. 2). The seal 18 is situated at one edge of the broad wrapping 14, but the narrow wrapping 15 extends partly over said edge and is loosely overlying. The reason therefore will be explained in the course of this description. The width of the composite wrapping, formed by the sealed broad and narrow wrappings 14 and 15 is equal to one dimension of the stack of sheets to be packed and the composite tubular wrapping is preferably longer than the other dimension of the stack. In a preferred embodiment the wrappings 14 and 15 are therefore delivered in web form and may already have been previously sealed together prior to the packing step.
At the back side of the stack 11, a more or less analogous combined tubular wrapping is provided but it is characterized in that it is broader than the first one.
Indeed, said second combined tubular wrapping which is pre-ferably delivered in web form too - will serve to enclose partially the whole stack 11 and must therefore have a width substantially larger than the,same one dimension of the stack plus twice the thickness of the stack.
The composite tubular wrappings 16 and 17 are sealed together in the same way, as the wrappings 14 and 15. The seal 20 is provided at the edge of the broad wrapping 17, and the narrow wrapping 16 is overlappingly sealed to the broad wrapping 17.

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Both combined wrappings are placed in correct position relstive to the stack 11 by locating them as that the edges of the broad wrappings 14 and 17 whicll are overlapped by the narrower wrappings 15 and 16 are at substantially the same distance from an edge of the stack 11. Then, the pro~ecting lengths of the combined wrapping formed by the wrappings 16 and 17 are folded over the stack and sealed to the combined wrapping formed by the wrappings 14 and 15, the seals thus formed being indicated at 19 and 21.
In this way a kind of tube is obtained in which the stack ; 10 11 and its optional protective covers 12 and 13 are enclosed. By forming another seal 24 between the pro~ecting portions of the composite strips along the other edges of the stack 11, this tube becomes hermetically closed, and an alr-tight, moisture-proof wrap is thus provided around the stack 11. When the stack is provided with protective covers 12 and 13, made of a relatively stiff high-; quality cardboard, the seal 18 may even be formed over a greater -~
area in order to fix both wrappings 14 and lS to protective cover 12.
- By the fact that the narrow wrappings 15 and 16 are sealed to the broad wrappings 14 and 17 respectively, in overlapping relation-- 20 ship thereto, and so as to leave the overlapping margins of the ~ -narrower wrappingsat least partly free, these free marginal portions of the narrower wrappings provide hand holds by which the said wrappings can be gripped and torn off in order to open the wrapper.
When the package is thus opened, the opened package has a clean and tidy appearance (see figs. 3a and 3b). In order to improve the ?, convenience of the package, at least one of the protective covers ~ may be provided with a zone of less mechanical strength such as .

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106Z'~09 I row of per1`oration; 22 or an incision 23 of about half the thickness of the protective cover 12 (fig. 3a and 3b).
This enables the operator, after having opened the wrap, to remove part of one of t~e protective covers 12 or 13, in order to facilitate re~oval of the first sheet of the stack 11 from the wrap. This feature too, is a remarkable advantage of the package according to the invention, because taking the first sheet of a slightly compressed stack is often rather difficult. The pro-vision of a partly free face at one upper margin of said first sheet permits the operator slightly to flex the latter, so that it can easily be taken between the thumb and the index of the hand~
The wrap, containing the stack of sheet materials may be placed in a box or enveloped in a supplementary wrapper, ~ade e.g. of corrugated cardboard. An exa~ple of such combined package is illustrated in fig. 4.
Said combined package 3~ comprises a corrugated cardboard sheet punched out in a form capable of enclosing the wrapped -pac~age. The small slot 35 corresponding with the ends of the flaps 31 is sealed by means of a self adhesive tape 34.
In this way the package 10 is safely enclosed. In order to facilitate the opening of the cardboard envelope, a tear-strip and/or a row of perforations 32 may be provided, wherein tearing or breaking the perforations is performed by pulling the tab 33.
~ ig. 5 represents a longitudinal cross-sectional view of a package which is more or less analogouS to the package illustrated in fig.1. ~he main difference between the GV.789PCT - 7 - , ' packages resides in the fact that the narrow tubular wrapping 15 extends over the tubular wrappings 14 and 16 and forms the link between both latter wrappings. This set-up results in an economy of packing material, because the tubular wrapping 16 may be narrower than in the case illustrated by fig. 1.
Fig. 6 represents the most simple embodiment of a package according to the invention. Instead of four, only two tubular wrappings of packing material, 25 and 26, are required and two seals, 27 and 28, suffice for sealing them together. The apparatus, capable of packing a stack in such an envelope may be kept relative-ly simple. A schematic view of such apparatus is represented in figs. 8a and 8b.
A transverse cross-sectional view of a package according to the invention is given in fig. 7 to illustrate the longitudinal seal 24 which is required along the side edges of the stack in order ~
to close the tube formed by the transverse sealing of two or four - -tubulsr wrappings of packing material.
Figs. 8a and 8b are views of the packing steps in order to enclose a stack of sheet materials into a package according to fig. 6.
In the apparatus two tubular wrappings 25 and 26 are treated which have already been sealed together with the help of the seal 28. Both webs may be continuously delivered in web-form from a previous manufacturing station (not represented).
The stack 11 is positioned on the sealed webs 25 and 26 .~. ~,.~

lO~;Z2Q9 in such a way that t~e I~lative positio~s between the seal 28 and its associated loosely overlying edge have already been situated in the exact order. ~o prevent a shifting of the webs, a kind of diaphragm in the form of a flexible perforated metallic sheet 42 is provided, the perforations 58 thereof being connected with the pipe 4~, communicating with a vacuum source (not shown) by means of a suitable flexible conduit 44. ~he pipe 4~ is capable of moving in axial direction through a concave member 59. ~his co~cave member 59 itself is yieldingly supported by means of springs 51 and 53, which enclose supporting membe.rs 50 and 54 respectively, which are capable of performing an axial slid-ing movement in their respective bushes 52 and 55. At either side of the concave member 59 are provided slideable supports 56 and 57, which are capable of sliding under the influence of the force~ exerted by the piston rods 48 and 49, which are secured to said supports with the help of solid blocks.
.- Above the concave member 59 a convexly shaped pressure member 45 is fitted, which may undergo a vertical movement in order to press on the stack of sheets 11. At the upper-most level is situated a heat-sealing electrode 47 built-in into a support 46.Preferably, the heat-sealing electrode may be made of ~EFLON material (registered trade-mark of E.S. Dupont . .
de Nemours - Wilmington, Delaware, U.S.A.).
At their upper side the slideable supports 56 and 57 bear the hinge leaves 40 and 41 respectively, which are capable of GV.789PCT - 9 -.

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106'~%09 performing a partial rotation of 180 degrees around their axes, the latter being situated in close proximity of the side edges of the concave member 59.
; When the heat-sealing step has to be carried out, the convexly shaped pressure member 45 is pushed in downward direction and ur~es against the stack 11, which is flexed ir.
order to conYorm to the curvature of the concave member 59.
Upon further pushing, the member 59 itself starts lowering, so that the level of the upper face of the pressure member 45 coincides with the plane of the hinge leaves 40 and 41. At that moment, said hinges perform a 180 degrees rotation, whilst ~ -~
folding the strips 25 and 26 around the stack 11. Subse-quentl~, air ~otors (not shown) are energized and urge the slideable supports 56 and 57 against the side edges of the stack 11 which beGomes completely immobile in this way. In the meantime a heat seal 27 (fig. 6) is formed by the sealing - electrode 47 which too has performed a vertical downward movement in order to contact the tubular wrappings 25 and 26. A tube of heat-sealable material is in this way laid around the stack 11. -Upon further moving the slideable supports 56 and 57 against the stack 11, the latter is further bent and the tube no longer closely ~its around the stack. This permits to retract the conve~ly shaped pressure member 45 out of the tube~ whereinafter the air motors are de-energized, enabling the slideable support~ 5h and 57 to withdraw and to tensio (,V.7~9P~ 10 -,~

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the stack 11 irl itc; enc:losure again,theIeby to her~etically close this part-ial pacl;age in a further sealing step (not represented).
From the f~regoin~, it may be concluded that a new and useful kind o~ package has been devised which sho~s the advantage of being easy to open, while maintaining a neat appearance when opened. Although the descriptior, of some pre-ferred embodiments was directed to a package comprising materials capable of being heat-sealed, this feature is how-ever not limitative for the scope and spirit of the inventionwhich shall be derived from the appended statements.

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Claims (14)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE
IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A package for a stack of sheet materials which is adapted to be opened at one end and to leave a defined edge around said opening, which package comprises a first tubular wrapping of sealable material enclosing a major portion of said stack around its sides and one end and terminating adjacent the opposite stack end along a defined edge, a second tubular wrapping extending in at least partial overlapping telescoping relation to said first tubular wrapping with its free end edge spaced from said defined edge of said first wrapping to constitute a skirt-like lower section, said first and second tubular wrappings being detachably sealed together around their contiguous periphery along a locus spaced from the free end edge of said second wrapping and leaving said lower skirt portion free for manual engagement to remove said second tubular wrapping bodily along said seal, leaving the stack within said first wrapping with its defined edge opening, and said sealed wrapping being uniformly tensioned around the stack periphery in its lengthwise direction, so that the stack is tightly contained therein.

2. A package according to claim 1, in which each of said tubular wrappings is in the form of a combined tubular wrapping, comprising at least two composite tubular wrappings, said composite wrappings being loosely overlappingly sealed to each other.

3. A package according to claim 2, in which said two composite tubular wrappings have a different width.

4. A package according to claim 1, in which said tubular wrappings are made of heat-sealable materials.

5. A package according to claim 4, in which said materials are a paper aluminium polyethylene laminate.

6. A package according to claim 2, in which the stack has at least one protective sheet at one of its surfaces.

7. A package according to claim 6, in which said seal is formed over a greater area to fix said first and second tubular wrappings to each said protective sheet.

8. A package according to claim 6, in which at least one of said protective sheets has at least one zone of less mechanical strength in the part extending over the edge of said first tubular wrapping.

9. A package according to claim 8 in which said zone of less mechanical strength is in the form of a row of perforations.

10. A package according to claim 8, in which said zone of less mechanical strength is in the form of a transversally extending incision over part of the thickness of said protective sheet.

11. A package comprising a stack of sheets in an enveloping wrapper, said wrapper comprising tubular wrappings of material sealed together in marginally overlapping relationship and forming a tube within which the stack is located, the ends of the tube having been sealed up so that the stack is totally enclosed, and the tube is uniformly tensioned around the stack periphery in its lengthwise direction, so that the stack is tightly contained therein, there being, across opposite faces of the stack, skirt-like portions, belonging to one or more of said tubular wrappings, which are not attached to the under-lying tubular wrapping portions which they overlap, so that a section of the wrapper, enclosing a part of the stack, may be removed by pulling on said free skirt-like portions to break the seals between that section of the wrapper and the remainder of it.

12. A package according to claim 1, in which said stack is a stack of X-ray films.

13. A combined package comprising an envelope enclosing at least one package according to claim 1.

14. A combined package according to claim 13, in which said envelope is in the form of a corrugated cardboard sheet capable of enclosing said at least one package, said envelope being closed with the help of a self adhesive tape and being provided at its inner periphery with a tear-strip for rupturing said envelope upon same.