US 3726058 A
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United States Patent 1 1 Stark (4 1 Apr. 10, 1973 METHOD OF PRODUCING PACKAGES HAVING PARALLELEPIPED SHAPE Sven Olof Soren Stark, Sodra Sandby, Sweden Inventor:
Assignee: Tetra Pak Developpement SA.
Filed: Jan. 15, 1971 Appl. No.: 106,673
Related US. Application Data Division of Ser. No. 43,] 19, June 3, 1970.
Foreign Application Priority Data Aug. 13, 1969 Sweden ..1 1242/69 US. Cl ..53/29 Int. Cl. ..B65b 43/10 Field of Search ..93/1 TS, 8 WA, 35 PC,
93/35 SB, 94 PS, 84 TW; 53/29 [56} References Cited UNITED STATES PATENTS 3,325,964 6/1967 Boitel ..53/29 X 3,603,217 9/1971 'Wright ....93/35 SB 3,373,663 3/1968 Heim ..53/29 X 3,567,074 3/1971 Brown ..93/35 PC FOREIGN PATENTS OR APPLICATIONS 879,545 10/1961 Great Britain ..93/35 PC 825,610 12/1959 Great Britain ..93/35 PC Primary ExaminerTravis S. McGehee Att0rney-Pierce, Scheffler & Parker 57 ABSTRACT A method of producing packaging containers in which a channel-shaped portion of a member is placed around an element having at least one transverse channel-shaped portion and is sealed to the edges of the legs of the transverse channel-shaped portions to form at least one closed packaging container.
8 Clains, 9 Drawing Figures PATENTED APR] 01975 7 SHEET 1 [IF 5 llllillll PATENTEU APR 1 01m 3; 726.058
SHEEI 2 BF 5 METHOD OF PRODUCING PACKAGESIIAVING PARALLELEPIPED SHAPE The present application is a divisional of my application Ser. No. 43,119 filed June 3,1970.
The present invention relates to a method of producing packaging containers having parallelepiped shape.
Packaging containers of parallelepiped shape are often used within packaging technology, the reasons for this being, naturally, the good stackability of the parallelepiped packaging containers and the small space they require in relation to their volume.
In the cases where, up to now, the parallelepiped containers were made from a strip of packaging material, this was accomplished by a comparatively complicated folding operation combined with pressure moulding or, also, by plastic deformation of a plastic hose or a flat plastic blank heated to its softening temperature.
The above methods entail certain drawbacks. The folding and pressure moulding operation involves e.g., a relatively large consumption of materials since moulding entails the formation of triangular corner flaps which are not included in the effective surface of V the package, while moulding by plastic deformation of a plastic material heated to its softening temperature involves uneven distribution of wall thickness and also distortion of any decorative pattern there may be, and in addition the moulding method is relatively slow. Apart from the above drawbacks, it has also been found difficult to avoid, in cases where filling is carried out in conjunction with the moulding operation, acquisition of the flavor of the plastic material by the goods being packaged. The above drawbacks are avoided by means of the invention which is characterized by its comprising two elements of channel section, which elements have an angular displacement in relation to one another and are joined along those of their edges that are in contact, in order to form a closed body. It is thus possible to produce a series of packaging containers according to the invention in a continuous row, the series of packaging containers being characterized by a continuous strip folded into a series of channel-shaped element (U-section elements) and by a long member of channel section which is substantially the same length as the folded strip, the said long member being placed around the said folded strip and sealed on the inside of the web to the tops of the channel-shaped folds of the folded strip.
The method of producing packaging containers in accordance with the invention is characterized by a first strip of relatively stiff foldable material being folded in a transverse direction so. as to form a series of channel-shaped elements all in a continuous row, after which a second strip of preferably the same material is formed into a long channel-shaped member, the width between the legs of the long channel-shaped member being made the same as the length of the transverse channel-shaped elements; the long channel-shaped member being placed over the strip folded into the continuous series of transverse channel-shaped elements in such a way that the tops of the folds are in contact with the inside of the base of the long channel-shaped member while the parallel sides of the long channelshaped member are in contact with the side edges of each of the transverse channel-shaped elements; and,
finally, by the long channel-shaped member and the transverse channel-shaped elements being joined to one another in a durable manner at those areas where they are in contact.
The invention will be described below by reference to the following diagrammatic drawings, in which FIG. 1 shows a package comprising two elements of channel section;
FIG. 2 shows a series of parallelepiped packages in a continuous row;
FIGS. 3 and 4 show strips of the packaging material;
FIG. 5 shows a strip of packaging material folded into elements of channel section FIG. 6 shows schematic apparatus for the production of packages in accordance with the invention;
FIG. 7 shows a cross section on line AA of the apparatus shown in FIG. 6, and
FIG. 8 shows a section on line BB of the apparatus shown in FIG. 6.
The package shown in FIG. 1 comprises two elements 1 and 2 of channel section which have an angular displacement in relation to one another and are fitted together in such a way as to form a parallelepiped body.
FIG. 2 shows a series of parallelepiped packaging units in a continuous row, each of which comprises elements 3 and 4 of channel section.
Between each of the packaging units situated in series alongside one another there is a space 5, and the packaging units can be separated from one another by tearing open the tear flap 8 which extends around the entire circumference of the channel-shaped member 3.
As will be seen in FIG. 2, the tear arrangement may consist of two lines of perforations located at a certain distance from each other, both of which extend around the whole of the channel-shaped member 3. Naturally, care must be taken to ensure that the tear lines are located within the space 5 between two adjacent packaging units. When a packaging unit is to be removed from the row of continuous packages, one end of the strip of materil 8 that is situated between the two lines of perforations is pulled up and the strip is then removed by pulling in the direction of the arrow. Since the channel-shaped member 3, in the region 5 between adjacent packaging units, is joined to the tops 16 (see FIG. 5) of the folds in the folded strip 13, it is best to have tear lines along the tops 16 of the folds as well.
The edge zone of the channel-shaped member 3 projects somewhat beyond the walls of the channel-shaped element 4, and the channel-shaped member 3 is in addition joined to a drawflap 9 which in FIG. 2 is shown folded down toward the face of the element 4. The method of producing a row of packaging containers in accordance with FIG. 2, as well as apparatus for carrying out the method, will be described below in greater detail with reference to FIG. 6.
The apparatus shown in FIG. 6 consists of an endless belt 18 which runs over driven wheels 31. Forming sections 26 which are connected to one another and which in this case consist of closed double-walled boxes, the insides of which can be connected to a source of vacuum, are fitted on the belt 18. At least those sides of the said boxes 26 which are turned away from the belt 18 are preferably providedwith holes or slots.
At an equal spacing along the belt 18, there are also fitted forming units 19 which project from the surface of the belt, and which also consist of double-walled boxes the insides of which are in connection with a source of vacuum, and whose side surfaces are provided with holes or slots. The belt 18 is equipped with such guide units that the said forming units 19 are arranged at right angles to the said forming sections 26, at least along those sections of the belt where movement is vertically downwards along a straight line.
The equipment also has heating units 22 which are situated on either side of the belt 18, preferably in the vicinity of the upper wheel 31. The heating units are located in such a way that the ends of the forming units 19 must pass in front of the heating units.
The apparatus furthermore comprises a device, not shown, for folding a flat sheet into the shape of a channel, and in order to facilitate this work, the strip may be pre-folded in the way shown in FIG. 4, which shows a strip of packaging material consisting of a carrier layer 11 of e.g., foam plastic or paper and a layer of homogeneous thermoplastic material laminated to the carrier layer 11. If desired the laminate may consist of foam plastic and aluminum foil. The strip of material is provided with a fold line 12 and, in the case illustrated, a plastic strip 32 projecting from the carrier material.
When the strip as shown in FIG. 4 has been folded into the shape of a channel, it will have the appearance as in FIG. 9, and as will be seen in FIG. 9, one leg of the channel-shaped member is extended by a draw flap 9, the function of which will be described later.
Another strip of material of the type shown in FIG. 3 also consists of a laminate comprising foam plastic or paper 11 and a homogeneous layer of plastic 10. The strip of material is pre-folded by fold lines 12 in order to facilitate folding of the material. The strip of material in accordance with FIG. 3 is designed to be folded in the manner shown in FIG. 5, i.e., the strip 13 is folded along the fold lines 12 in order to form narrow folds 14 which have the same height and width and are spaced uniformly along the strip 13. The flat tops of the folds 14 are denoted by 16 and the space between two adjacent walls of the folds by 17.
The folded strip in accordance with FIG. 5 is made by folding the preformed strip 13 as in FIG. 3 along the fold lines 12 with the aid of equipment not shown here in greater detail, which may in principle consist of a rotatable or reciprocating pusher unit, by which the strip 13 is folded and inserted over and between the forming units 19.
As described before, the forming units 19 and the forming sections 26 situated between the forming units are connected to a source of vacuum and are provided with holes which open onto the surfaces of the forming units 19 and the forming sections 26, situated between the forming units are connected to a source of vacuum and are provided with holes with open onto the surfaces of the forming units 19 and the forming sections 26, which means that the strip 13 folded over the forming units 19 will be drawn against the surfaces of the forming units 19 and the forming sections 26 and will be retained there by suction during the whole of the forming operation.
The distances between the fold lines 12 situated on the strip 13 must naturally be the same as the height of the fold forming units 19, the length of the forming sections 26 and the width of the forming units 19.
The width of the strip 13 is preferably such that it is somewhat wider than the width of the forming units 19, which means that an edge zone of the strip 13 will project by a matter of a few millimetres beyond the side edges of the forming units 19.
When the strip 13 has been drawn down between the protruding forming units 19 and made to adhere to the sides of the forming units 19 and the top surfaces of the forming sections 26, the strip folded in this way is carried past the heating units 22, the parts of the folded strip 13 which project from the side edges of the forming unit being heated to sealing temperature. After passing by the heating units 22, the folded strip 13 is carried vertically downwards, the forming unit 19 assuming a position at right angles to the forming sections 26, which means that the folds 14 will be situated at right angles to the strip 13. In this position, the folded strip 13 is joined onto the previously mentioned member 3 that has been folded into the shape of a channel, which has been arranged with its web facing the tops 16 of the folds 14 and with its legs against the heated edge zones 15 of the folded strip 13.
Goods to be packaged are introduced through the fill pipe 20 which has an elongated narrow section and is located between the tops 16 of the folds 14 of the strip 13, and the inside of the web of the channel-shaped member 3.
Since the fill pipe 20 must necessarily have some width, the web 29 (see FIG. 7) of the channel-shaped member 3 undergoes deformation in the region of the fill pipe. In order that this deformation should not set up harmful stresses in packaging materials which have slight elasticity, it is possible to arrange longitudinal fold lines in the web of the channel-shaped mamber 3, which, when the web of the member is stretched in the transverse direction,will accommodate the fill pipe without difficulty between the web 29 of the member 3 and the tops 16 of the folds 14 in the folded strip 13. If required, it will naturally be possible to arrange a numner of longitudinal fold lines along the web of the member 3 in order to allow for even greater expansion of the web.
The legs of the channel-shaped member 3 and the side edges 15 of the folded strip 13, which have been heated to sealing temperature, are joined to one another by means of pressure units in the manner shown in FIG. 7, which is a cross section on line A-A of the apparatus shown in FIG. 6. When the legs of the channel-shaped member 3 are joined to the edge zones 15 of the folds 14 on the strip 13, there are formed parallelepiped spaces 33 (FIG. 6) which are separated from one another by the folds 14. In the case of carrier material of e.g., paper, in order to obtain a larger contact surface within the sealing area, the edges 15 of the folded strip 13 should be upset or folded in over the ends of the forming units 19 before the heating of the thermoplastic layer takes place. The spaces 33 are however in communication with each other since the web of the channel-shaped member 3 in the region of the fill pipe is not joined to the tops 16 of the folds 14 on the strip.
The parallelepiped spaces 33 are filled with the goods to be packaged, and, after a filled section has passed the orifice of the fill pipe, the web of the channel-shaped member 3 is sealed to the top 16 of the folds 14 on the strip by means of a sealing unit 21. Sealing by the sealing unit 21 may be accomplished by the use of heat, but practical tests have shown that ultrasonic sealing is to be preferred. FIG. 8 shows a section on lines BB through the apparatus shown in FIG. 6. After the sections have been filled and sealed by the sealing unit 21, they can be removed by means of a cutter unit 24 that acts along both the tops and side edges of the forming units 19.
Naturally, it is not necessary to cut away each package, and, as shown in FIG. 2, it is possible to remove a certain number of packaging units together in a continuous connected form and can be separated later on continuous connected form and can from one another through the tear flaps 8 which are best arranged on the strip of packaging material prior to the folding operations.
By providing the strip of packaging material to be folded into a channel member 3 with a projecting free platic edge 32 as shown in FIG. 4, it is possible to make e.g., the top of the package from a thinner material, i.e., the carrier layer can be left out. The fact that the top portion is made from a thinner material may be an advantage when the package is to be opened, which is further facilitated by the projecting plastic edge 32 being made wider than the width of the folds 14 in the folded strip of material 13, which means that a draw flap 9 is provided which will further facilitate opening of the package by tearing off the top portion.
The constructional version of the invention described above and the method of its production have been found very advantageous, but it is naturally possible, within the framework of the idea underlying the invention, to modify both the package and the equipment. It is possible for instance to make use of packaging materials other than those referred to above, and it is naturally also possible to modify the apparatus used for the production of the packages and also the sealing units.
What is claimed is:
l. A method of producing packaging containers having a substantially parallelepiped shapt comprising folding the leading end of a first strip element of relatively stiff foldable material transversely of its length to form a plurality of uniform, transverse, channel-shaped portions in a continuous series in the element, folding at least a portion of the leading end of a second strip member of relatively stiff foldable material, longitudinally to provide at least a portion thereof with a channel-shaped cross-section, the space between the legs of the longitudinal channel-shaped portion of the member being substantially the same as the width of the legs of the transverse channel-shaped portions of the element, placing the longitudinal channel-shaped portion of the member about at least one of the transverse, channelshaped portions of the element so that the ends of the legs of the transverse, channel-shaped portions of the element contact the inside surface of the central web mentioned line of contact.
. A method as claimed in claim 1 wherein the first strip element is moved into engagement with forming means and further comprising applying suction to the forming means for forming the legs of the transverse, channel-shaped portions of the element and the connecting web therebetween so as to form each of the plurality of transverse channel-shaped portions of the element, said forming means being disposed between adjacent legs of adjacent channel-shaped portions and abutting the outside of the connecting web portion.
3. A method as claimed in claim 1 and further comprising heating those portions of at least one of the surfaces of the longitudinal, channel-shaped portions of the member and the edges of at least one of the transverse, channel-shaped portions of the element which form one of the sealed contacts before the longitudinal, channel-shaped portion of the member is placed about the at least one of the plurality of transverse channelshaped portions of the element.
4. A method as claimed in claim. 1 wherein the space between the legs of the longitudinal, channel-shaped portion of the member is less than the width of the legs of the transverse, channel-shaped portions of the element to an extent such that when the member and element are sealed together the edges of the legs of'the transverse, channel-shaped portions of the element will be deformed to form flange-like elements sealed to the legs of the longitudinal, channel-shaped member.
5. A method as claimed in claim 1 wherein the web portion of the longitudinal, channel-shaped portion of the member is deflected outwardly from the ends of the legs of the transverse channel-shaped element after the member is disposed about the element to permit filling the spaces formed by the transverse, channelshaped portions of the element after the side edges of the legs thereof have been sealed to the legs of the member.
6. A method as claimed in claim 1 wherein the last mentioned sealing step is carried out by ultrasonic means.
7. A method as claimed in claim 1 and further comprising separating adjoined packaging containers along lines therebetween and extending transversely of the connected series of packaging containers.
8. A method as claimed in claim 7 wherein the separation is made along tear strips provided between adjoining packaging containers.