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This invention relates to the general field of containers, and more particularly to containers of which at least a part is made of heat-shrinkable film, e.g.-synthetic resin.
Various conventional containers made of flexible film, e.g., paper or synthetic resin film, are well known. Exemplary of these is the shopping hag. ~owever, when filled with solid objects, powder, or the like, these known containers have the disadvantage that they are usually unstable when stood upright on their`bottoms, since the way in which these bottoms are sealed does not usually allow for them to open flat, and perpendicular to the sides of the containers. Further, if the containers are placed on a sharp or rough surface, there is a danger that their bottoms may be punctured by the surface, thus rup-turing the containers. Thus, often, a reinforcing mer~er is required to strengthen, the bottom of such a container. Such a reinforcement is also often required to support the weight of a heavy load charged into the container. Therefore, up till now, a design has been lacking for a simple and robust container, which is substantially free from the aforementioned defects.
It is therefore an object of an aspect of the present inven-tion to provide a container which is substantially free from the abovementioned defects, which is strong, simple, and useful.
According to an aspect of the present invention a one-piece container is provided cornprising a side wall and a bottom and formed from a single piece of heat-shrinkable material; wherein the mechani-cal characteristics of the side wall and the bottom, after formation of the container differ substantially from each other; and wherein the side wall is more soft and more pliable than the bottom.
By one variant, the bottom is substantially thicker than - ` ~ 1 5~2~9 \
the side wall.
By yet another variant, the heat-shrinkable film has a thickness, before shrinking, in the range of 0.004 to 0.2 millimeters.
By a variation thereof, the material is a heat-shrinkable film and the heat-shrinkable film has a thickness, before shrinking, in the range 0.004 to 0O2 millimeters.
By other variants, the container includes a pair of handles pro-vided thereon which are suitable for liting the container; or a pair of holes are provided in the part of the wall remote from the bottom, which are suitable for lifting the container.
'`" ~1~82~9 In the accompanying drawings, Fig. 1 is a perspective view of a container which is an embodiment of one aspect of the present invention;
Fig. 2 is a longitudinal cross-section of the container of Fig. l;
Fig. 3 is a longitudinal cross-section of another embodiment of another aspect of the present invention;
Fig. 4 is a longitudinal cross-section of two e~amples of still another embodiment of aspects of the present invention, showing them as stac~ed up on:one another;
Figs. 5(a) and 5(b) are schematic views of a method for producing a container, according to another aspect of the present invention, Fig. 6 is a perspective view of the material for making a container according to an aspect of the present invention, to be used in a method schematically illustrated in Fig. 7;
Figs. 7~a) and 7(b) are schematic views of another method for pro-ducing a container;
Fig. 8 is a longitudinal cross-section of another embodiment of a container according to another aspect of the present invention;
Fig. 9 is a perspective view o the container of Fig. 8;
Fig. 10 is a ]ongitudinal cross-section of the container of Fig. 8, while it is in use.
Fig~ 11 is an elevational view of another embodiment of a container according to another aspect of the present invention;
Fig~ 12 is a longitudinal cross-section, taken along the line XII-XII in Fig. 11;
Fig. 13 is an elevational view of another embodiment of another aspect of the present invention;
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Figs. 14 and 15 are perspective views of other embodiments of con-tainers according to other aspects of the present invention;
Figs. 16(a), 16(b), 16(c) and 17 are longitudinal cross-sections of still other embodiments of containers according to still other aspects of the present invention;
Figs. 18(a), 18(b), and 18(c) are cross-sections of synthetic resin films having air cells, which are used for producing containers according to various aspects of the present invention;
~ Figs. l9(a) and i9(b) are schematic views of a method for producing the container of Fig~ 17 according to an aspect of the present invention;
; ~ Fig. 20 is a longitudinal cross-section of another embodiment of a container according to another aspect of the present invention;
` Fig. 21 is a longitudinal cross-section of yet another embodiment of a container according to yet another aspect of the present invention;
Fig. 22 is a perspective view of yet another embodiment of a con-tainer according to yet another aspect of the present invention, in use;
Fig. 23 is a longitudinal cross-section of the container of Fig. 22, taken along the line XXIII - XXIII;
~ ~ Fig. 24 is an exploded perspective view of the container of Fig. 22;
~ Figs. 25 and 26 are longitudinal cross-sections of other embodiments of containers according to other aspects of the present invention;
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Fig. 27 is a perspective view of the container of Fig. 26, in use;
~ Figs~. 28, 29, and 30 are longitudinal cross-sections of yet still other embodiments of containers of yet still other aspects of the present invention; and Fig. 31 is a perspective view of another embodiment of a container of another aspect of the present invention, ir, use.
~ ~5~2~9 In the figures, like reference numerals with different suffix letters in the different figures denote corresponding parts.
The heat-shrinkable film material used in the present invention may be polypropylene, polyvinyl chloride, poly-ethylene, polyester, a laminate thereof, or the like. The thickness of the film material should be in the range of O.004 to O.2 mm, and the shrinkage of it by heat should be at least 3~.
Referring to Figs. 1 And 2, there is shown a container 1 accord-ing to an aspect of the present invention, which comprises a cylindrical side wall 2 made of a soft heat-shrinkable film material, and a circular bottom 3, made of a substantially harder and less flexible and pliable material, e.g., synthetic resin, cardboard, or the like, the side wall 2 being coupled to the bottom by a coupling portion 4, which is a part of the side wall 2, and which is folded inwards and heat-sealed to the bottom, as is hereinafter described. This container may of course be charged with contents, and often the top 5 oE it is then heat-sealed.
The shape of the bottom 3 of co~lrse is not restri~ted to be circu-lar; it may be rectangular, elliptical, triallg~ r, and so forth.
In figs. 3 and 4 other containers la and lb according to other aspects of the present invention are ~hown. Th~se differ some~hat from the container of ~igs. 1 and 2 d in that the bottom is not separate from the wall, but is formed in one piece with it out of a heat-shrinkable film. However, the bottom is substantially harder and less pliable than the film of the side walls, both becau~e it is thicker, and because in fact .. , .
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The containers of fig. 4 are so formed as to stack up conveniently on one another.
Fig. 5 illustrates a method according to an aspect of this invention for producing the container 1 of Figs. 1 and 2. A heat-shrinkable tube 2 and a hard bottom plate 3 are set on a former 20, as shown in Fig. 5(a), with the edge of the tube 2 around the plate 3 and protruding slightly above it. Then the projecting edge of the tube is folded down against the plate 3, to make the coupling portion 4, and the : heat plate 21 is lowered down onto i~ and heat-sea}s it to the : ~ bottom. Then the finished container iæ~released from the former 200 :
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In Fig. 7 is shown a method according to another aspect of this mvention for producing the;container shown in Fig. 3.
~ ~A heat-shrinkable tubular film with its end sealed in a U
shaped round bottom 6, as shown in Fig, 6, is placed on the former 20, and the round bottom 6 is pressed down to contact with the uppe{ surface 22 of :
the former 20, so as to cause wrinkles, as~shown in Fig. 7(a). Then not air 23 is directed onto the wrinkled bottom 6, and thereby the bottom 6 is shrunk, as shown in Fig. 7(b). The finlshed container is then released from the former 20.
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~ ~ 5 ~ 9 The bottom 3a of the finished container is much stifEer than its wall, both because it is somewhat thicker and denser than the wall, due to the surplus of material which originally formed the wrinkles, before heat-shrinking, and because due to the heat-shrinking it has lost its flexibili-ty.
In Figs. 8-10 is shown another container lc, which has the same construction as the one of Fig. 1, except that a reclosable sealant member, i.e. a ~IPPER comprising a convex member 9cl and a concave member 9c2 is attached to the upper inner surface of the side wall 2c, instead of sealing the open top. Thus the open top can be sealed as shown in Fig. 10, and can be opened and resealed again, which is very useful.
In Figs. 11 and 12 is shown another container ld according to another aspect of the present invention. This container is sealed along a sealing line 8d by heating, and the unnecessary part 11 of the side wall 2d is cut off.
In Fig. 13 is shown another container le according to another aspect of the present invention, in use. The container is sealed accord-ing to the form of the contents therein, by heating.
In Figs. 14 and 15 are shown other containers of other aspects of this invention lf and lg, which have the same constructions, except that a pair of handles gf are provided on container f, and a pair of holes 9g are provided in container lg for lifting them.
In Fig. 16 are shown other containers lh according to other aspects of the present invention, which are similar to the aforementioned ones, ex-cept that in Fig. 16(a) the bottom is concaved i.e. the bottom projects downwardly, 3h; in Fig. 16tb~, it is convexed, i.e. it protrudes inwardly, 3h; and in Fig. 16(c), two containers are provided which have one common piece of material for their bottoms. This could be of particular use in special appli-.
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In Fig. 17 is shown another container li, of another aspect of thisinvention, which is particularly distinguished by the fact that the materials of which the side wall and bottom are formed have air cells formed in them.
This container has good cushioning effect on the contents, and also heat - resistance.
Fig. 18 shows the sort of material of which the container of Fig. 17 is made. The air cells could be on either the inside (Fig. 18(a)) or the outsidè`of the container (Fig. 18~b)). As another possibility, ~Fig. 18(c)), they could be provided on both sides of the wall and bottom.
Fig. l9 shows the method of another aspect of this invention by which the container of Fig. 17 is made. This is similar to the method des-cribed for Figs. 5(a) and 5(b) except that the heat plate 21 has to have a cutaway in it, so as not to break the air cells in the bottom while heat-sealing the wall to the bottom.
In Fig. 20 is shown a container 1~ according to yet another aspect of the present invention, which has air cells in the wall but not in the bottom; and in Fig. 21 is shown a container lk of that sort, formed as a doubIe COntAiner~ with one piece of material serving as the bottom of two containers.
In Figs. 22 - 24 i~s shown another container lQ, of another aspect of this invention which comprises a side wall 2Q which is made of a palr of heat-shrinkable film pieces by sealing the longitudinally opposite sides 12 together, and which has an elliptical hard bottom plate 3~ which is coup-led to the side wall~ 2'~ at a coupling portion 4~ of them, by heat sealing, in the same manner as described above.
This container also includes a reclosable sealant member, i.e.
ZIPPER 9 ~ , which comprises a convex member 9X 1 and a concave member 9~ 2, and which is attached to the upper inner side wall 2,Y .
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Fig. 19 shows the method of another aspect of this invention by which the container of Fig. 17 is made. This is similar to the method des-cribed for Figs. 5(a) and 5(b) excepc that the heat plate 21 has to have a cutaway in it, so as not to break the air cells in the bottom while heat-seal-ing the wall to the bottom.
In Fig. 20 is shown a container lj according to yet another aspect of the present invention, which has air cells in the wall but not in the bottom; and in Fig. 21 is shown a container lk of that sort, formed as a double container, with one piece of material serving as the bottom of two containers.
; In Flgs. 22 - 24 is shown another container 1 ~ , of another aspect of this invention which comprises a side wall 2~ which is made of a pair of heat-shrinkable film pieces by sealing the longitudinally opposite sides 12 together, and which has an elliptical hard bottom plate 3~ which is coupled to the side walls 2~ at a coupling portion ~ of them, by heat seallng, in the same manner as described above.
This container also includes a reclosable sealent member 9~ 2, and which is attached to the upper inner side wall 2~ . The contents, desig-nated by 10 ~ , are put into the container, and the ZIPPER is closed. Then the container 1 ~ is further heat sealed above the ZIPPER 9~ , the sealed - portions being designated in the figure by 8~ hen the contents are to be flrst used, the upper sealed portions are cut off, and the ZIPPER is opened, and thereafter may be used to reseal the container.
In Fig. 25 is shown another container of another aspect of this in-vention lm, which is of the same construction as the one in Fig. 1, except that the~cylindrical side wall 2m is made of a heat-shrinkable net. This container is useful for packing fruit or the like.
In Figs. 26 and 27 is shown another container of another aspect of this invention ln, which is the same as the container of Fig. 25, except that .: ~
it has a bottom formed as the frustrum of a cone, 3n. The open top may be tied shut by a ribbon 13n.
In Fig. 28 is shown another container of yet another aspect of this invention lp, which is of the same construction as that of Fig. 1, except that the bottom member 3s is made of polystyrene foam, and i9 of substantial thickness, with a pocket formed therein adapted to receive a fruit, and further that the cylindrical side wall 2p includes a plurality of small open-ings 14 for ventilating the inside of the container.
In Fig. 29 is shown another container of still another aspect of 1~ this invention lq. This container is similar to that shown in Fig. 28, ex-cept that the side wall 2q which is made of a heat-shrinkable film and which is heat-sealed to the polystyrene bottom extends only a short way upwards, and is then heat-sealed or secured by adjesive to a non-heat-shrinkable cylindrical film 2q at an overlapping portion lS.
In Fig. 30 is shown another container of yet another aspect of this invention lr, which is the same as the one shown in Fig. 28, except that no - small openings are formed in the side wall 2r, and that the bottom member 3r includes a groove 16 around its lower periphery, into which a coupling portion 4r of the wall 2r is sealed by ~leat-sealing.
2~ - In Fig. 31 is shown another container of a further aspect of this invention ls which is the same as the one shown in Fig. 28, e~cept that no small openings are formed in the side wall 2s. The open top is sealed by a ribbon 13s.