PROCESS FOR PACKAGING ARTICLE WITH FILM

Abstract: This invention relates to a process for packaging an article (4) with a thermoplastic resin film (1) in which the film (1) is rolled on two rolls (2) on both sides so that an intermediate region (1A) thereof may be extended in tension condition between the rolls (2), and article (4) to be packaged is fed through a space between the rolls (2) so as to push against the extended intermediate region (1A) of the film (1) and be wrapped therewith, and overlapped portions (1a, 1b) of the wrapping film (1) are set in parallel with the surface of the article (4) and are fused together, and at the same time are cut so that there may be obtained such a fused adhesion line (5) on the overlapped portions (1a, 1b, 1c, 1d) of the film (1) that extends in the lateral width of the film (1) and is longer in length than the width of the film (1), so that there is obtained the packaged article (4) in which the fused overlapped portions (1a, 1b) of the packaging film (1) is laid along on the surface of the article (4) and, on the other hand, there is obtained an intermediate region (1A) of the film (1) which is extended between the two rolls (2) and has the foregoing fused overlapped portions (1c, 1d).

Description: DETAILED EXPLANATION OF THE INVENTION This invention relates to a process for packaging various kinds of articles with a synthetic resin film. As for a packaging technique of this kind, there has been hitherto known, i.e. from US-A-3 922 362, such a type as described below Namely, a thermoplastic film is used for a material for packaging an article, and, as shown in Fig. 9A, the film a is wound on a pair of rolls b, b, respectively so as to be extended between the two rolls b, b, and this film a is wrapped, at its intermediate region, round an article c in such a manner that the article c is pushed to be sent forward through a space formed between the two rolls b, b, and the resultant overlapped portions of the intermediate region of the film a wrapping the article c are fused together and cut, by a fusing and cutting machine d, so that there is obtained the packaged article c of which the packaging film a has a fused overlapped end portions connnected together through a fused adhesion line e, as shown in Fig. 9B, and, on the other hand, the resultant separate opposite side regions of the film a connected to the rolls b, b are also fused together, at their cut end portions, so as to be connected one with another through a fused adhesion line e to form an intermediate region of the film extended between the rolls for being ready for the next packaging operation. Accordingly, by repeating of the foregoing packaging operations, there is obtained the resultant packaged article with the overlapped end portions having the fused adhesion line e, e, as shown in Fig. 9B. If the film is a shrinkable film, the packaged article is then introduced into a heating chamber f and is heated so that the film a may be shrunk to become adhered closely to the article c for obtaining a packaged product, as shown in Fig. 9C. In general, the width of the film a to be used is larger than the width of the article c so that by the shrinkage caused by the heat treatment, marging regions a′ thereof are shrunk to be adhered closely to the peripheries of both end surfaces of the article so as to have a frame-shaped cover portion for protecting the article, as shown in Fig. 9C. According to the foregoing conventional packaging process, the overlapped end portions of the packaging film are protruded outwards perpendicularly to the surface of the article as clearly shown in Fig. 10, and are fused together to form a fused adhesion line e. However, the fused overlapped portions are comparatively weak at this fusion adhesion line e thereof, because the overlapped portion are weakened by the fusing adhesion treatment. Therefore, the fused adhesion line is applied with such a pulling force in the opposite directions of arrows shown in Fig. 10 that is any external force or a shrinkage force of the film caused by the heat treatment thereof, it often happens that the film is broken at the fused adhesion line e. Accordingly, it is necessary to use as packing film a comparatively thick and strong one. From FR-E-83640 is known that the fused lines are longer than the width of the film. This invention has for its object to provide a packaging process for removing the foregoing defect caused by the weakening of the fused adhesion line as involved in the conventional packaging process, and obtaining a durable fused adhesion line. According to the invention this object is achieved by processes as characterized in Claims 1 and 2. In the packaging process of this invention, the overlapped portions of the film are fused together under a tension or loose condition thereof. As for the packaging film, any of an ordinary type, a stretch type or a shrinkable type may be used. Embodying examples of this invention will now be explained with reference to the accompanying drawings wherein BRIEF EXPLANATION OF THE DRAWINGS Figs. 1A, 1B are diagrams for generally explaining packaging steps of one embodying example of a packaging process of this invention, Fig. 2 is a perspective view of a packaged article obtained by the process of this invention, Fig. 3A is a sectional views taken along the line III - III in Fig. 2 for illustrating the section of the fused adhesion line of overlapped portions of the film packaging the article, Fig. 3B is a sectional view of another example similar to Fig. 3A, Figs. 4A,4B,4C,4D are plan views for illustrating various shapes of the fused adhesion lines formed by this invention, Fig. 5 is a plan view of another embodying example of this invention, Fig. 6 is a side view of further another embodying example of this invention, Figs. 7A - 7E are diagrams for explaining operative steps of a packaging apparatus for carrying out this invention process, Figs. 8A - 8J are diagrams for explaining operative steps of another packaging apparatus for carrying out this invention process, Figs. 9A, 9B, 9C are diagrams for explaining operative steps in a conventional process, and Fig. 10 shows sectional views of fused adhesion portions by the conventional process. As shown in Fig. 1A, a thermoplastic synthetic resin film 1 is wound on a pair of rolls 2, 2, respectively, so as to be extended under tension between the two rolls 2, 2 through a pair of contact rolls 3, 3, and under this condition, an article 4 to be packaged is placed on a roller conveyer and is pushed to be fed in the direction shown by an arrow, through a space formed between those rolls, so as to push forward an intermediate region of the film 1. Accordingly, the film 1 is wrapped, at the intermediate region 1A, round the article 4 so as to embrace the same, and the resultant mutually embraced portions, that is, both end portions 1a, 1b of the intermediate section 1A of the film 1 are fused together to form a fused joint line 5 in the width direction of the film 1, and are cut to obtain the resultant separate side regions 1B, 1B of the film 1 connected to the rolls 2, 2, so that there is obtained the package article 4. On the other hand, the separate opposite side regions 1B, 1B of the film 1, that are separated from the intermediate region 1A′ of the film packaging the article thereof, are fused together at their cut end portions 1c, 1d to form a fused adhesion line 5 so as to form a new intermediate region 1A of the film extended between the two rolls 2, 2 for being ready for packaging for the next article 4, as shown by imaginary lines in Fig. 1B. Fig. 2 shows the resultant packaged article 4. The foregoing fused overlapped portions 1a, 1b, that is, the opposite end portions 1a, 1b of the intermediate region 1A′ of the film 1 packaging the article 4 are laid along on the surface of the article 4 so that the overlapping surface thereof may be in parallel with such a pulling force in the opposite directions shown by arrows that is generated by an external force applying thereto or at the time of shrinkage of the packaging film 1, as shown in Fig. 3A and Fig. 3B. In this case, the overlapped portions 1a, 1b mutually fused together at the fused adhesion line 5 are of such a type that the portion 1b is a two-fold one and is overlapped with a single layer of the other portion 1a, not folded, as shown in Fig. 3A, those 1a, 1b may be so modified that the portion 1b is not folded and a single layer thereof is overlapped with a single layer of the other portion 1a, as shown in Fig. 3B. In either case, these overlapped portions 1a, 1b are fused together to form the fused adhesion line 5 in the width direction of the film 1 so that the line 5a may have such a length that is longer than the width ℓ of the film 1 as a zigzag-formed line one shown in Fig. 4A, a arc wave-formed line shown in Fig. 4B, an intermittent slash-formed line shown in Fig. 4C, a trapezoid or tooth-formed line shown in Fig. 4D or the like. If there is used the thermoplastic synthetic resin film 1, for instance, a shrinkable one which is larger in width than the article 4, the same is shrunk to be adhered closely to the article 1 by the heat treatment, and marginal portions thereof are formed into a frame cover film portions adhered closely to the peripheries of end surfaces of the article as shown clearly in Fig. 2. It is usual in the packaging process of this invention that a single sheet of film 1 is used as in the foregoing example, but in a case where there is required especially a durable packing that two sheets of films 1, 1 may be used in mutually layered condition as shown in Fig. 5, and in a case where a packaging of a larged-sized article is required, it can be considered that two sheets of film 1, 1 are so used as to wrap the same in such a manner that their end edges 1′, 1′ are put one upon another as shown in Fig. 6. Next, one embodying example of the process of this invention will be explained with reference to Figs. 7 and 8 as follows:- Figs. 7 and 8 show a packaging apparatus for carrying out the process of this invention. In this embodying example, a thermoplastic film of strech type or shrinkable type or the like is used for a packaging film 1. The apparatus in Fig.7A - 7E is so constructed that there is provided a pair of rolls 2, 2 between which the film 1 is bridged and is wound thereon, and rolls of the film 1 on the rolls 2, 2 are applied with proper braking force so that an intermediate region 1A of the film 1 may be extended in its tension condition between two rolls 2, 2 through the contact rolls 3, 3, and there is disposed ahead of the extended region 1A of the film 1 a pair of movable rods 6a,6b which are movable inwards and outwards in the mutually opposite right and left directions and are also movable in upper and lower directions (perpendicularly to the drawing sheet surface), two pair of clamping and fusing members 7a, 7b which are movable in the upper and lower directions and are movable to open and close, and a film cutter 8 arranged to be moved to advance and retreat in relation to the film 1 by a driving mechanism 8a such as an air cylinder or the like. With the foregoing apparatus, as shown in Fig. 7A, if the article 4 to be packaged is placed on a roller conveyer and is pushed to be fed forward through a space formed between the two rolls 2, 2, from the rear side of the film 1 shown by imaginary lines, in the direction of an arrow, so that the intermediate region 1A of the film 1 in its tension condition may surround the three side surfaces of the article 4, as shown by solid line in Fig. 7A. At that time, if necessary, the article 4 is held immovably so that both side surfaces thereof may be held by expansion of a pair of pushing members 9, 9 provided on both sides. Thereafter, by moving the right and left movable rods 6a, 6b inwards so as to cross each other beyond the center line of the article, such both side regions 1B, 1B of the film 1 extending to the rolls 3, 3 that are in engagement with the rods 6a, 6b may be bent and crossed each other beyond the center line to be formed into mutually overlapped bent portions 1B, 1B covering the top surface of the article 4, as shown in Fig. 7B. Thus, the wrapping of the article with the intermediate region 1A of the film 1 extending to rolls 3, 3 is completed. During this wrapping operation, the two pairs of clamping and fusing members 7a, 7b are set aside at their elevated or lowered positions so as not to obstruct the foregoing wrapping operation. After completion of the foregoing wrapping operation, the two pairs of clamping and fusing members 7a, 7b are moved forward to be so positioned as to be opposite to such respective bent and overlapped film regions of the wrapping film as shown in Fig. 7C. Thereafter, as shown in Fig. 7D, each pair of clamping and fusing members 7a, 7b are closed, so that the respective three film layers thereof are fused together in the lateral direction of the film to form respective fused adhesion lines 5, 5 each of which is longer in length than the width of the film, and in addition the middle portion between the two fused adhesion lines 5, 5 is cut by the cutter 8. The time of cutting by the cutter 8 may be either before the fusing operation under clamping operation, simultaneously with or after the fused adhesion operation. After the completion of the foregoing fusing and cutting operations, the movable rods 6a, 6b are moved upwards or downwards to slip off from the bent region of the film 1, and the two pairs of the clamping and fusing members 7a, 7b are opened and are retreated to the original inoperative waiting positions. As a result, there is obtained such a packaged article that the article 4 is packaged tight with intermediate region 1A′ of the film 1 separated from the film connected to the two rolls 2, 2, and at the same time, there is, on the other hand, obtained the resultant intermediate region of 1A of which the overlapped cut end portions 1c, 1d are fused together. Namely, there is obtained the resultant intermediate region 1A of the film 1 extended in its tension condition between the rolls 2, 2 through the contact rolls 3, 3 for being ready for the next packaging operation for the next article, as shown in Fig. 7E. Thereafter, the packaged article is taken away from the position shown in Fig. 7E, and then the foregoing packaging procedures as shown in Figs. 7A - 7D are repeated for achieving continuous packaging process. If a shrinkable film 1 is used, a packaged article is introduced into a heating chamber so that the packaging film 1 may be shrunk to obtain a closely fit packaged article. The fused adhesion overlapped portions 1a, 1b of the film 1 obtained by foregoing embodiment is of the type that, as shown in Fig. 3A, the overlapped portion 1b thereof connected to the roll 2 on one side is a two-fold one, that is, two layers, and the overlapped portion 1a thereof connected to the roll 2 on the other side is a single layer. In addition, the overlapped portions 1a, 1b are fused together under their tension condition, and accordingly the resultant fused joint line 5 of the resultant fused joint overlapped portions 1a, 1b is subjected to a pulling or tearing force in addition to being weakened by the fusion of the film, so that the overlapped portions 1a, 1b are feared to be broken at that fused joint line 5. Therefore, it is preferable that the overlapped portions 1a, 1b be joined together in their loose condition. Next, another embodying example for meeting the foregoing desire will be explained with reference to Figs. 8A - 8J. Figs. 8A - 8J show a packaging apparatus for carrying at the foregoing preferable packaging process of this invention. The apparatus is so constructed that a pair of opposite movable rods 9a, 9b movable to open and close, and another pair of opposite movable rods 9c, 9d movable to open and close are disposed on both sides of the right and left end portions of the intermediate region 1A of the film 1 extended in its tension condition between the two contact rolls 3, 3, and additionally a pair of movable rods 9e, 9f are disposed on the left side and the right side and in front of the movable rod 9b and the movable rods 9d on the left side and the right side, and sucker members 10a, 10d, 10e, 10f, each being swingable by a driving means (not shown) as an air cylinder mechanism or the like are provided near the foregoing movable rods 9a, 9d, 9e, 9f, and in addition clamping members 11a, 11b arranged to be moved to advance and retreat by respective air cylinders 12, 12 are disposed on the left side and the right side and between the movable rods 9b, 9e on the left side and the movable rods 9d, 9f on the right side, and the movable rods 9a, 9b, 9e and the air cylinder 12 on the left side, and the movable rods 9c, 9d, 9f and the air cylinder 12 on the right side are mounted on the respective base tables 13a, 13b which are synchronously movable to the right and the left in the mutually opposite directions so as to become either nearer one to another or farther one from another, and additionally a sucker box 14 is so provided as to be movable to advance to or retreat from an middle position intermediate between the movable rods 9e, 9f. With the foregoing apparatus, the packaging process of this invention is carried out in such a manner that, after the article is pushed to be fed forward through a space formed between the contact rolls 3, 3, and pushes forward the intermediate region 1A of the film 1 so that the intermediate region 1A may surround the three side surfaces of the article 4, as shown in Fig. 8A the sucker box 14 is moved to advance to its operative position shown by the solid line in Fig. 8B, and then, the base tables 13a, 13b on both sides are moved inwards so that such right and left side regions of the film that extend to the respective contact rolls 3, 3 from both outsides of the article 4 may be drawn nearer one to another towards the center line, and under their pressure contact with the movable rods 9b, 9d and the movable rods 9e, 9f which are being moved inwards as far as the movable rods 9e, 9f are brought into contact with the respective side surfaces of the sucker box 14 for holding the respective both side film regions therebetween, and under this condition the pair of the movable rods 9a and 9b and that of the movable rods 9c and 9d are closed respectively for holding the film 1 therebetween as shown in Fig. 8c, and thereafter, the air cylinders 12, 12 on both sides are driven to advance the clamping members 11a, 11b, and synchronously with this, the sucker members 10a, 10d, 10e, 10f are swung inwards for holding the respective opposite film regions by suction operation thereof, as shown in Fig. 8D, and this condition, the clamping members 11a,11b are further advanced so that a cutting blade 14c provided in one of the clamping members 11a,11b may be inserted into a cutting blade receiving groove 14d made in the other clamping member 11 to cut the film 1, and as a result, the resultant cut free end portions of the film region 1A′ of the film covering the article 4, and the resultant cut free end portions of such resultant separate opposite regions 1B, 1B of the film that are apart from the intermediate region 1A′ packaging the article 4, but are connected to the contact rolls 3, 3 are held, by suction, by the respective sucker members 10e, 10f, and the sucker member 10a, 10d, respectively, and thus, on one hand, a pair of the free end portions 1c, 1d projecting from the respectively film portions clamped between the movable rods 9a, 9b, and the movable rods 9c, 9d, respectively, are obtained in their loose condition released from the tension condition, and, on the other hand, a pair of the free end portions 1a, 1b projecting from the film regions clamped between the movable rods 9e, 9f and both side surfaces of the sucker box 14 respectively are obtained in such loose condition that has been released from the tension condition previously applied thereto, as shown in Fig. 8E, and thereafter the sucker member 10a holding the free end portion 1c of the film 1 is swung counterclockwise in the drawings so that the free end portion 1c of the film held thereby may be moved to a position which is in alignment with the line of the opposite right and left side portions 1B, 1B of the film extended between the contact rolls 3, 3 on both sides, and in addition the sucker member 10e holding the free end portion 1a of the film is swung so that the free end portion 1a may be put on and sucked by the surface of the sucker box 14, and then the suction operation of the sucker member 10e on the free end portion 1a is stopped so that the free end portion 1a is transferred onto the sucker box 14, and then the sucker member 10e is swung back to its original position, and thus there is obtained the free end portion 1a under its loose condition on the sucher box 14, as shown in Fig. 8E, and thereafter the sucker member 10d is swung towards the sucker member 10a, and the sucker member 10f is swung towards the surface of the sucker box 14 so that the free end portion 1d sucked by the sucker member 10d may be put on the free end portion 1c held by the sucker member 10a and the free end portion 1b held by the sucker member 10f may be put on the free end portion 1a on the surface of the sucker box 14, as shown in Fig. 8F. Thus, the respective overlapped free end portions 1a, 1b and 1c, 1d are fused together under the resultant loose condition, that is, in the width direction of the film to form the respective fused joint line 5, 5 that is longer than the width of the film, by respective pairs of fusing members 7a, 7b provided on the pair of the sucker members 10a, 10d and the pair of the sucker member 10f and the sucker box 14, respectively. As a result, there is obtained a packaged article 4 in which the article 4 is packaged with the intermediate region 1A′ of the film 1 of which the overlapped cut end portions 1a, 1b are fused together, and, on the other hand, there is established a new intermediate region 1A having a fused adhesion line 5 interconnecting the cut end portions 1c, 1d of the separate opposite side regions 1B, 1B of the film 1 connected to the rolls 3, 3, and thereafter as shown in Fig. 8G, the sucker members 10d, 10f are swung back to their original positions, and the pair of the movable rods 9a, 9b, 9c, 9d are opened from each other, and the intermediate region 1A of the film 1 is extended in the tension condition between the contact rolls 3, 3. Additionally, the base tables 13a, 13b are moved outwards in the opposite directions shown by arrows, and also the sucker box 14 is retreated to its original position and the apparatus is restored to the original condition shown in Fig. 8A for being ready for the next packaging operation, and at the same time there is obtained the article 4 packaged with the film 1 wrapping closely round the same, as shown in Fig. 8H, and the fused joined overlapped portions of the film packaging the same are obtained in their flat condition along on the surface of the article 4. Thus, according to this invention, the overlapped end portions of the synthetic resin film wrapped around the article are set in parallel with the surface of the article, and are fused together in the lateral direction of the film so as to form a fused adhesion line which is longer than the width of the film, so that there can be used a wrapping film which is decreased in thickness as compared with that used in the case of the foregoing conventional packaging process, and the strength of the fused overlapped portions of the film packaging the article can be increased in strength and durability against a tearing force, owing to the elongated length of the resultant fused adhesion line of the fused overlapped portions thereof, and owing to the fact that the overlapped end portions are laid along on the surface of the article, the film is can be prevented from breaking at the fused adhesion line at the time of the shrinking of the film, and actually there can be used the packaging film which is smaller in thickness and strength by above about 50%, than that used in the conventional packaging process.

Claims: A process for packaging an article (4) with a film wherein a synthetic resin film (1), which is wound on a pair of rolls (2), respectively so as to extend between the two rolls (2), is wrapped, at its intermediate region (1A), round on article (4) fed through a space formed between the two rolls (2), and the resultant overlapped end portions (1a, 1b) of the intermediate region (1A) of the film (1) are fused together and cut so that there may be obtained a packaged article (4), and at the same time, the resultant separate opposite side regions (1B) of the film (1) connected to the two rolls (2) are fused together, at their overlapped portions (1c, 1d), to obtain a next intermediate region (1A) extending between the two rolls (2) for being ready for the next packaging operation, and wherein the article (4) in the space between the two rolls (2) is moved so that the intermediate region (1A) of the film (1) in its tension condition may surround three side surfaces of the article (4); characterized in that the both side regions (1B) of the film (1) extending from the article (4) to the rolls (2) are moved across each other to form an overlapping portion and respectively clamped; and that the overlapping portion is fused together in the lateral direction of the film (1) to form continuous or intermittent fused lines (5) that are longer than the width of the film (1) and cut, such that the overlapped end portions (1a, 1b) of the intermediate region (1A) are fused together with one of the end portions (1a, 1b) folded back on itself so as to form a fused portion comprising three layers of film together with the other end portion, and are made to lie along a surface of the article (4), and the other of the overlapped end portions (1c, 1d) are also fused together with one of the end portions (1c, 1d) folded back on itself so as to form a fused portion comprising three layers of film together with the other end portion, and are made to lie in the plane of the next intermediate region (1A) extending between the rolls (2). A process for packaging an article (4) with a film wherein a synthetic resin film (1), which is wound on a pair of rolls (2), respectively so as to extend between the two rolls (2), is wrapped, at its intermediate region (1A) round an article (4) fed through a space formed between the two rolls (2), and the resultant overlapped end portions (1a, 1b) of the intermediate region (1A) of the film (1) are fused together and cut so that there may by obtained a packaged article (4), and at the same time, the resultant separate opposite side regions (1B) of the film (1) connected to the two rolls (2) are fused together, at their cut overlapped end portions (1c, 1d), to obtain a next intermediate region (1A) extending between the two rolls (2) for being ready for the next packaging operation, and wherein the article (4) in the space between the two rolls (2) is moved so that the intermediate region (1A) of the film (1) in its tension condition may surround three side surfaces of the article (4), characterized in that the both side regions (1B) of the film (1) extending from the article (4) to the rolls (2) are moved towards each other by movable means (9b, 9d, 9e, 9f) so as to form two portions extending in the feed direction of the article; that the respective side regions of the film (1) are clamped separately and cut; and that the resultant cut free and clamped end portions (1a, 1b) of the film region (1A') covering the article (4) and the resultant cut free and clamped end portions (1c, 1d) of the opposite region (1B) of the film are clamped and fused together in respective overlapped end portions (1a, 1b; 1c, 1d) to form continous or intermittend fused lines (5) that are longer than the width of the film (1), such that the overlapped end portions (1a, 1b) of the intermediate region (1A') are made to extend in opposite directions and to lie along a surface of the article (4) and that the other of the overlapped end portions (1c, 1d) are also made to extend in opposite direction and to lie in the plane of the next intermediate region (1A) extending between the rolls (2). A process for packaging an article (4) as set forth in any one of the foregoing claims, characterized in that the synthetic resin film (1) is made of a thermoplastic resin such as of ordinary type, strech type or shrinkable type. A process for packaging an article (4) as set forth in any one of the foregoing claims, characterized in that the one of the overlapped portions (1a, 1b) of the film is fused under a tesioned condition or a loose condition thereof.

Inventors: HOSAKA, YUKIO, SAITO, TSUTOMU
Applicants: KABUSHIKI KAISHA FUJI SEISAKUSHO
Application year: 1987
Main classification: B65B9
IPC codes: B65B9, B65B11, B65B53