IE50467B1

IE50467B1 - Package for aromatic contents and process for its production

Info

Publication number: IE50467B1
Application number: IE1804/80A
Authority: IE
Original assignee: Schur Int As Brdr
Priority date: 1979-08-28
Filing date: 1980-08-27
Publication date: 1986-04-30
Also published as: FI802711A; EP0024596A1; NO154830C; AU6155380A; NO802535L; FI69611C; DK363880A; DE2934673A1; IE801804L; CA1156194A; EP0024596B1; DE3066976D1; ATE6617T1; NO154830B; FI69611B; JPS5632260A; AU536317B2; DK150723B

Abstract

1. A packaging means in the form of a bag for filling materials which are aromatised and/or which are to be kept moist, comprising a filled bag portion (5) which is formed by two oppositely disposed wall portions (6, 7) of plastics foil, wherein its bottom edge is formed by folding the plastics foil (3) over along a bottom fold (10), while at its two side edges (11, 12) the oppositely disposed wall portions (6, 7) are fixedly sealed together, wherein the upper edge (13) that forms the opening of the bag is peelably closed by a sealing seam (4) extending parallel to the bottom fold (10), in such a way that the sealing seam (4) can be opened without tearing the wall portions (6, 7), characterised in that the sealed seams (14) of the two side edges (11, 12) of the oppositely disposed wall portions (6, 7) extend with a high degree of seam strength to the upper edge (13) of the opening of the bag and that the peelable sealing seam (4) crosses (at 15) the lateral sealed seams (14) in the region of the upper edge (13) in such a way that the sealing seam (4) is peelable only between the points (15) of intersection of the seams.

Description

Description of the Prior Art A tobacco bag is known, from German Offenlegungsschrift No. 2,518,229, in which the upper edge forming the opening of the bag is not closed. One of the two wall portions which forms the bag in its lower portion, namely the rear wall portion, is elongated into a fold-over flap, which lies against the outside of the bag portion when the bag is folded up. An adhesive paralleling the bottom fold line is intended on the one hand to close the upper wall at the top edge and on the other hand in the adjacent area to close the rear wall portion. However, in this manner an aroma and moisture sealing closure is not achieved. In addition, the tobacco bag is not advantageous in either manufacture or use. - la A tobacco bag is also known from‘German Offenlegungsschrift No. 2,840,223. There, the sealing seam paralleling the bottom fold is between wall parts or different plastic materials, so a breakable welded closure is achieved. If the bags are formed, as taught by these Offenlegungsschrifts, by folding an elongated piece of material along a transverse bottom fold, e.g., at about one-third from the end of the material strip, the inner layer of the bag consists of a first material type and the outer layer of a second material type. The upper edge of the front wall is folded inward and welded directly to the adjacent inside of the rear wall. In this manner two different material types face one another upon welding, and by appropriately adjusting the materials, their seam strength upon welding can be reduced to an extent that a peelable welded seam is attained. However, this reduction of seam strength also applies to the sealed seams of the two side edges of the bag, i.e. when so-welding two different materials, it has not been possible to form the seam seals of differing seal strength -- one of relatively low strength which can be peeled open and an adjacent one of high strength which resists opening when the neighboring low strength peelable seal is opened. Specifically, it has been found, disadvantageously, that the user, when opening the peelable closure seam at the outer edges, also pulls apart the upper areas of the lateral sealing means. These packages are then, disadvantageously, no longer firmly sealed along their sides with great sealing strength.

Packages are also known, e.g. folding tobacco pouches or flat bags, in which seam strength is reduced not by folding over, as in the example described above, but by striplacquering one surface. In this the disadvantage has been encountered that solvents evaporate into the bag contents and, upon bag opening by the ultimate consumer, solvent residues in the form of solid crumbs drop into the bag contents. -2An additional disadvantage of known packages having breakable or peelable closure seams is damage caused to the package during the sealing process when the bag contents are first sealed into the bag. When heat for sealing the wall parts together is transmitted by heated jaws, an unattractive seam, visible to the final customer, is formed on the rear side of the seal, i.e., on the outside of the finished tobacco bag. This can even destroy the decorative bag design in the case of less than careful θ production and in any event an unattractive appearance results.

Summary of the Invention This invention improves a bag of the initially mentioned type by providing a peelable closing seam created in place without the bag lateral permanent edge seals being even partially damaged, and wherein damage to the bag outer surfaces is also avoided.

This goal is achieved, in accordance with this invention, in that the sealing seams of the two side edges of 2Q the bag opposing wall portions exhibit high seam strength all the way to the upper edges at the bag opening, and the peelable, closing seam crosses the sealing seams in the area of their upper edge, proximate the bag opening, in such a manner that the seam is peelable only between the points where the peelable seam crosses the side edges sealing seams -350467 By the invention, a package is produced which has high seam strength at the crossing points of the peelable closing seam at the top outer edge of the bag and the two lateral sealing seams. The consumer can open such a package without particular care along the peelable, openable closing seam by pulling the front wall portion away from the rear wall portion so that the closing seam is opened up from the center toward both sides. This opening process is brought to a stop at the crossing points with the side sealing seams as a result of the great strength of the side sealing seams. In this manner, a pleasant and very advantageously usable package is created, especially for use as a tobacco bag. The new arrangement of the closing seam also provides increased stability of the packaged contents since, before opening, the aroma and the moisture are retained within the package to a great extent because of the hermetic sealing provided by the high strength lateral side seals and the peelable closure seal. An adhesive, such as a lacquer coating or the like as provided in conventional bags is not used. In accordance with the invention, the bag is closed without aid of foreign materials, which could mix with the packaged material and affect its taste and with other qualities. Material strips with plastic films are also usable with improved properties and, advantageously, while improving the stability of the tobacco, the tightness of closure of a tobacco bag can be improved, and the foldover flap provided in the customary tobacco bags can even be eliminated without impairing the barrier properties.

It is also advantageous in accordance with this inven30 tion if the closing seam travels from one longitudinal side -4edge of the bag to the other. In this way, production can be improved and production speed increased since the bags are produced by feeding the bag material in the longitudinal direction. The equipment used can also be made simpler, since the exact length of the closing seam is not very important.

Brief Description of The Drawings Figure 1 is a vertically sectioned schematic isometric view of the preferred embodiment of the bag of the inven10 tion, with the section taken to show only the righthand half of the bag; Figure 2 is a broken section view taken as indicated by circle A in Figure 1; Figure 3 is a broken section view taken as indicated 15 by circle B in Figure 1; Figure 4 is a broken front view of another embodiment of the bag of the invention. -5Description of the Preferred Embodiments The bag as shown in Figure 1 includes a laminated triple layered material strip 30, the outer plastic film 1 of which is preferably composed of polypropylene with good optical transmission properties. The middle layer 2 is a paper insert. (The majority of final consumers, especially smokers, prefer a bag, especially a tobacco pouch, produced in the traditional manner with a decorative paper insert enclosed by transparent films.) The third layer 3 of the material strip is the interior plastic film which depending on its selected components absorbs high-frequency radiation in the desired manner. As a result, it is possible to produce seam 4 as an openable, peelable sealing seam. The seam 4, along with the layer structure 1, 2 and 3 of the material strip 30, of which the bag is formed, is clearly shown in Figure 1 or on an enlarged scale in Figure 2. The structure of layers 1, 2 and 3 is visible in Figure 3. The reopenable sealing seam 4 preferably is perpendicular to the longitudinal direction of the material strip 30 and is indicated by line x-x-x in Figures 1 to 4.

In the embodiments of Figures 1 and 4, the bag generally designated 5 is formed by two opposing wall portions 6 and 7. If one views the partially opened bag according to Figures 1 and 4, 6 designates the front wall portion and 7 designates the rear wall portion. The rear wall portion is elongated upwardly in excess of the length of the front wall portion, to form a flap portion 8. In the embodiment of Figure 1, this flap portion is visibly longer than in the embodiment of Figure 4. By means of an adhe30 sive strip 9 shown only in Figure 4, flap portion 8 is made -6to adhere at the bottom or on the rear side of the exterior of the bag after filling the package and folding over. In the embodiment shown in Figure 1, the flap portion 8 is of longitudinal length exceeding that of front portion 6, so that when flap 8 is wrapped around the bag, downwardly over front portion 6, generous overlap of front portion 6 by flap 8 is provided; this furnishes redundancy to the seal provided by peelable seal 4.

The bottom edge of the bag portion 5 is defined by 10 the bottom fold 10. The two side edges 11 and 12 extend transversely from the bottom fold 10 to the preferably sealed upper edge 13, which defines the opening of package .

While the peelable closing seam 4 preferably extend15 ing parallel to traverse bottom fold 10 is shown in both the embodiments of Figures 1 to 3 and in Figure 4, the lateral sealing seam 14 is only shown on the right hand side in the embodiment of Figure 4, as a double broken line. There is also shown crossing point 15, at which reopenable peelable closing seam 4 crosses the lateral sealing seam 14. Therefore, Figure 4 shows in particular how the lateral sealing seams, with uniform and high seam strength, extend from the bottom fold 10 to the upper edge 13, so that the peelable sealing seam 4 has low seam strength only between crossing points 15, while at the crossing points 15 the seam strength is equal to that of the lateral sealing seams 14. -7ου 4 t>7 For sales reasons, it is sometimes advantageous if metallized material strips are used to provide decoration and reinforcement of the bag exterior. A further development of the invention in this regard is then characterized by the fact that the closing seam is located on the nonmetallized interior between two superimposed, external selectively metallized wall parts. In this manner, very attractive packages can be produced with the metallized film, and nevertheless the closing seam can be arranged by simple means for closing the bag opening in the manner that it can be opened, so that it can be peeled open only between the crossing points with the lateral sealing seams at the outer corners, so that the side edges, even in the case of bag material having selectively metallized surfaces, have a great seam strength all the way up to the top.

The term metallization as used herein denotes a partial, ribbon-like coating of selected areas of the laminate external surface film 1 with metal. In the high-frequency welding area, i.e. the area exterior of reopenable peelable seal 4, on the outside of the package and, naturally, also on the inside of the package, no metallization is present, in order, for example, to prevent an electrical short circuit. Since this area on the flattened-out bag laminate blank appears in ribbonlike from, the strip metallization likewise takes place, so to speak, in ribbons on the corresponding area. The ribbons of metal strengthen the package.

The invention furthermore pertains to a process for 30 producing the bag described in the proceding, in which a laminated material strip including the plastic film -8is pulled longitudinally from rollers, folded around a bottom fold transverse to the feed direction to form the bag portion, and then welded parallel to the feed direction at the side edges of the bag and separated, after which the contents are packed in and the bag is thermally closed along the reopenable peelable closing seam connecting the side edges. The package with the characteristics presented in detail in the preceding is attained when, in accordance with the invention, the closing seam is produced while lightly pressing together the two parts of the material strip which are to be welded together and simultaneously applying high frequency energy to achieve welding. Actually, high frequency welding with a frequency of 27 MHz is preferred in accordance with the invention. Naturally, however, the high frequency welding can also be performed under other conditions. In particular, by means of high frequency welding the unattractive distortion of the decorative pattern provided by the metallization ribbon due to pressing through the welding jaws along the closing seam can be avoided. By means of a suitably constructed material strip, especially the plastic film or films incorporated in it, it is possible to ensure that the material strip at its surfaces which are to be welded together more or less absorbs the energy of the high frequency radiation, so that a truly peelable welding closing seam can be attained without destroying the surfaces of the material strips.

In this process, it may be advantageous if, in accordance with the invention, the high frequency welding -9jaws are preheated to 40°C. With this preparatory measure the high frequency welding can be used especially rapidly and with definitive effect.

An important feature of this invention is provided by the peelable sealing seam construction and the high strength side seam construction whereby two laminate surfaces are sealed to form the bag, where the laminate consists of three distinct and different layers, with the seal formed between facing surfaces of a common layer of material, namely inner film 3. Thus, there is no need to effect a seal between dissimilar materials. The rugged outer plastic film remains intact to form the exterior of the package, providing protection against package rupture.

Bag 5 has mutually facing front and rear portions 6 and 7 formed from a common piece of laminate material with the portions joining at a fold 10 defining the bag bottom. The lateral sealing seams 14, which are of high strength and noted in Figure 4, extend the longitudinal length of and join together corresponding longitudinal margins 12 of the bag. The peelable heat seal 4 is hand-openable and accordingly is of substantially lower strength than the side seam seals 14. The peelable seal joins the front and rear portions 6 and 7 of the bag together, extends transversely to side seals 14 and is longitudinally removed from fold 10 defining the -10bag bottom. The transverse extremities of the hand peelable seal 4 overlap the respective side seam seals 14 as shown at 15 in Figure 4 to thereby provide seam crossing zones of great strength so that hand peelable seal 4 can be opened only between the seam crossing zones. The rear portion of the bag extends longitudinally from peelable seal 4, oppositely from fold 10 beyond front portion 6, a distance at least equal to longitudinal length of front portion 6. This facilitates folding of the thereby created extension portion 8 of rear portion 7 over front portion 6 and over the hand peelable seal 4 to thereby provide greater isolation of the bag contents when the bag is reclosed after opening seam 4.

An important feature of this invention is the con15 struction whereby the bag is folded from a single piece of laminated material in such manner that all seals are made between facing surfaces of a common material, in this instance interior plastic film 3. This contruction allows all exterior surfaces of the bag to be made of a common material, namely outer plastic film 1.

Claims

1. A package for aromatic contents and/or contents in which moisture is to be retained, comprising means forming a filled bag portion formed by two opposing wall parts made of plastic film, said package having a bottom 5 edge formed by folding over the plastic film along a bottom fold line, while on the two side edges the opposite wall portions are permanently sealed together by lateral sealing seams, wherein the upper edge, forming the opening of the bag,is closed by a closing seam running parallel to the bottom fold, 10 and is openable by peeling, the closing being effected such that the closing seam can be opened without tearing the wall portions, characterized in that the said lateral sealing seams extend with great sealing strength to the upper eage of the package opening 15 and that the peelable closing seam crosses the lateral sealing seam in the area of the upper edge in such a manner that it (the closing seam) can be peeled apart only between the crossing points.

2. Package in accordance with Claim 1, character20 ized in that the closing seam extends from one side edge of the package to the other.

3. Package in accordance with Claim 1 or 2 characterized in that the closing seam is arranged on a nonmetallized inner side between two superimposed, externally metallized wall parts. -124. Process for producing a package wherein a material strip with a plastic film is pulled from rollers, folded around a bottom fold paralleling the feed direction to form a bag portion, and then is welded transversely

4. 5 to the feed direction along the side walls of the bag and separated, after which the contents are packed and the bag is closed thermally along a closing seam which connects the side edges, characterized in that the closing seam is produced while gently pressing together the two parts 10 of the material strip which are to be welded together and simultaneously performing high frequency welding. 5. Process in accordance with Claim 4, characterized in that the high frequency weld is performed at a frequency of 27MHz.

5. 6. Process in accordance with Claims 4 or 5, characterized in that the high frequency welding jaws are preheated to 40°C.

6.

7. A package for aromatic contents comprising: a. a bag including front and rear mutually facing portions formed of a common piece of laminate 5 material, said portions joining at a material fold defining the bag bottom; -13b. side seam heat seals of high strength extending the length of and joining together corresponding longitudinal margins of facing surfaces of front said rear portions; 10 c. a hand peelable heat seal seam of substanttially lower strength than said side seam heat seals, joining facing surfaces of said first and rear portions together, transverse to said side seals, longitudinally removed from said fold; 15 wherein traverse extremities of said hand peelable seal overlap said respective side seam heat seals to provide seam crossing zones of great strength so that said hand peelable seal can be opened only between said seam crossing zones; 20 wherein said laminate is a three layer lamination consisting of an outer layer of polypropylene, a central layer of paper and an inner layer of flexible thermoplastic with said facing surfaces of said first and second portion being said flexible thermoplastic.

8. The package of Claim 7 wherein said polypropylene surface of said laminate is metallized in the area above said side seam heat seals. -Η

9. The package of Claim 7 wherein said rear portion extends longitudinally from said hand peelable seal oppositely from said fold, beyond said tront portion a distance at least equal to longitudinal length of said 5 front portion, to facilitate folding of said extension of said rear portion over said front portion, over said hand peelable seal and over said fold.

10. A package for aromatic contents and/or contents in which moisture is to be retained, substantially as described herein with reference to Figures 1-3 or Figure 4 of the accompanying drawings.