Method and apparatus to implement double opposed containers fed as a continuous band to filling stations and apt to be sealed by welding, as well as the packages thus obtained

Abstract: Method to implement a band (30) of containers (A and B) in flexible material, arranged on pairs with opposed apertures (2) and (4), respectively joined by a center strip (20). The band of containers may be wound in the form of a coil or concertina folded up in boxes (34) to be successively utilized in a simple manner and are apt to afford high productivity also to small packaging companies, with the use of relatively economical equipment suitable to fill the containers, generally, with liquid products and successive sealing of same. The containers are conceived so as to be realized with both single and multi layer walls, with or without aluminium and may also be fitted with a bellows base apt to maintain the containers in an upright position for display on shelves for sale.

Description: The invention relates to a method according to the preamble of claim 1. Such method is known from FR-A-1 044 871. The invention further relates to an apparatus according to the preamble of claim 8. Such apparatus is known from US-2 671 587. In the field of packaging, especially for consumer products, the present tendency is to simplify filling operations and reduce the container size in order to achieve economic savings. The use of leightweight materials facilitates transportation of the packages and collection of the used containers, thereby reducing disposal costs. Presently for example,bulkier and costlier containers for liquid detergents have been replaced with small envelopes made of flexible material, e.g. in form of bags containing only the concentrated detergent which can to be diluted at home with water. The envelopes when empty weigh just a few grams, occupy only a negligible space in the refuse bin and are easily disposable by combustion, thereby permitting recovery of energy. The envelopes also conveniently replace conventional rigid type packages made of glass or metal containing liquids of various chemical and industrial nature. If the envelopes are sterilized and prepared with an aseptic filling system, they are also suitable for long term containment and of food products of various degrees of fluidity, such as milk, juices, concentrates or other alimentary pulps. In addition to the above advantages of a practical economic and sanitary nature, a better display on the shelves of supermarkets can be realized, a package of flexible material which once filled, will draw the attention of the consumer as it can be placed in an upright position in a better display, and a wide surface on which inscriptions can be printed. The purpose of the invention is to establish a method for the fabrication of containers of flexible material to be used especially for products in the liquid state and compatible with automatic packaging apparatus resulting in a good productivity, and being at the same time simple and economical, making the method accessible also to small packaging companies . According to the invention the method is characterized by the features of claim 1. A particular type of ribbing for stiffening the packing can be obtained by heat sealing the sides of the bottom of the single containers during preparation of the band so as to obtain self supporting packages able to stand in an upright position on the shelves of shops and characterized also by a wide external surface on which inscriptions may be conveniently printed. In the second fabrication step, the filling equipment which is to receive and utilize said coupled containers in semi-finished form as a product already fit for final packing, can be simplified and relatively economical affordable even by the smaller packaging companies. For a more reliable and better utilization of the band of coupled containers and in order to improve the productivity of the filling equipment, the apparatus is characterized by the features of claim 8, so as to facilitate the introduction of the product at the relevant point of the filling station. The invention will now be described with reference to the annexed drawings showing the preferred embodiments both in regard to the prefabrication of the container band and to the equipment utilizing the bands. Fig. 1 is a plan view of a pair of containers with bellowed bottoms forming an integral part of the continuous band according to the invention; Fig. 2 is a schematic cross-sectional view of the same pair of containers shown in Fig. 1, taken along lines II-II; Fig. 3 is a bottom view of a packaged container fitted with a bellows; Fig. 4 shows a pair of containers without bottom bellows; Fig. 5 is a cross sectional view along lines V-V of the container pair shown in Fig. 4; Fig. 6 is a top view of a band of container pairs, arranged on a plane; Fig. 7 is a perspective top view of the unwinding, filling and sealing equipment for the containers according to the invention; Fig. 8 is a top view of a detail of divaricating device coinciding with the filling station; as shown in Fig. 7. Fig. 9 is a side view of Fig. 8, Figs. 1 and 2 show a pair of containers, A and B with bellowed bottom and respective apertures 2 and 4 opposite to each other. In the figures, T indicates the transversal dimension of a pair of containers pre-formed and laid on a plane, L the finished width of a container, H the height, d the distance between openings 2 and 4 and h the height of a double S fold of the lateral edges. The pairs of containers A and B,identified altogether by number 1, is formed, starting from a band having an original width equal to T+2H+4h wide, which is folded as shown in cross section in Fig. 2. This figure shows,in particular a single layer package of coupled flexible material of which at least surface 6 and relative folded surface 6' both of which are internal surfaces, are heat sealable while external surfaces 7,7' made of a different material can act as a reinforcement, both to improve appearance and to provide a space for markings, inscriptions etc. Successively, heat seals 14,14' perpendicular with respect to longitudinal axis X-X of the band ,are performed, at longitudinal intervals L equal to the width of the containers to be produced, so as to form two ribs constituting the lateral sealed closures of the container. The seals extend at a distance C equal to a few millimeters below the edge of apertures 2 or 4 of the container in order to obtain less rigid lips and more easily separable flaps to improve the filling operaton.In order to produce packages able to support themselves in a vertical position, the lateral ends of the folded band are pressed by suitable shaped heatable jaws 8 and 8' to provide, at the bottom of each container,the union of the opposite heat weldable surfaces 6,6' shaping the welding in the form of an arc of a circle, as shown by the hatched surfaces 10,10' of figs. 1 and 2, along an arched line 17 having the concavity facing toward the respective apertures 2 and 4. To laterally join the two edges of the bellows of each bag,at least one welding notch 16 can be formed if necessary and, depending on the type of material used, on each of the two side edges of the bellows. As a result of which, the melting of the material of internal layer 6 acts as a binder for the external non-heat sealable material, causing the union of the overlapped bellows edges in the lower part of the containers. Figure 3 is a bottom view of one of containers A or B after filling, which sets itself, due to the weight of the included product, with the bottom bellows expanded to form a supporting base. Number 19 in fig. 3 indicates the lower edges of the bellows formed by the assembly of the coupled sheet with its internal heat sealable surface, closed laterally along ribs 14,14'. Number 17 (see also Fig. 1) indicates the arched bottom line formed in each container, by the double seal 10,10',while number 18 identifies the internal folding line of the bellows. Before collecting a band 30 of containers thus formed (see fig. 6), ribs 14,14' are divided transversally with cuts 25 at their mid line without affecting the unfolded center strip. Cuts 25 extend only in proximity of the lateral ends of the folded band in order to detach one container from the other on the same row and keep the containers connected in pairs by means of middle strip 20 having width " d " and also at a point coincident with their bottom zone. In this way , once the container is filled with a liquid or powder, a deformation of the bottom occurs, forming a bellows 11 which permits the container to be vertically self supporting. Another simplified embodiment, of the container pairs without the bellowed bottoms but still within the inventive scope described, above is illustrated in figs. 4 and 5. This embodiment is respectively similar to figs. 1 and 2, and relative to a package in which only one folded band 9 of heat sealable material is subjected to lateral heat sealing 14a, to obtain a very economical pairs of containers A' and B' interconnected by a central strip 20 of width "d", similar to the pairs or containers shown in Figs. 1 and 2. Figure 6, of the pairs of containers has a continuous band 30 of pairs of containers the center strip 20 which is identified by printed notches 24 or perforated on its center line with pin holes 22, after which the band 30 is wound on a spool or folded concertina wise into boxes 34 to be supplied to the packaging companies for filling of the bags by the unwinding, filling and sealing facility identified altogether by 40 in Fig. 7. The facility is equipped upstream with a support 42 inclined toward box 34 and centered with strip 20 which connects the pairs of containers A and B to be foldeded in the box itself. Proceeding toward the filling and sealing stations, the containers A and B set themselves astride the support 42 which further on, at position 43 progressively become larger, until when, coinciding with drawing assembly 44, the support forms a track 46 having transversal width "d" having practically the same width as strip 20 (see figs. 8 and 9). A driving pinion 47 is provided in drawing assembly 44; the pinion having teeth engaging in holes 22 in strip 20,so as to achieve a regular positive advancement of packages A and B, toward the filling station 48, with the edges of their respective apertures 2 and 4 divaricating. Alternatively, the advancement of the band of containers can be governed by a photocell (not shown) also able to detect the notches 24 stamped on strip 20 at suitable distances from each other. In order to obtain an adequate and reliable opening of apertures 2 and 4 of the bags (see figs. 8 and 9) a device 49 representing a gradual marked reduction of width "d" of track 46 is provided. Device 49 viewed from the top, has an x configuration at filling station 48, with curved side walls 50,51 along a tract M equal to the chord of a width L of a container in the unfolded status. Within the tract M, the arched walls 50,51 show a raised back 52 so that the deformation impressed by the raised back on the strip 20 connecting the opposite pairs of containers A and B, forces the walls 6 and 7 of the single containers to adhere to arched surfaces 50 and 51 whilst the corresponding outer walls curve outwardly in the opposite direction to cause a suitable divarication of the edges of apertures 2 and 4 in a position coinciding with the outlets of filling station 48. The adherence of walls 6 and 7 of the containers to arched walls 50,51 of track 46,can be aided by suitable guide elements. Other suitable means such as suction systems may be provided to achieve the same purpose. The drawing of the band of packages 30 can be aided by another pinion gear 58 located downstream of heat-sealing station 60 which performs hermetic sealing of apertures 2 and 4 of the containers. A cutting assembly 60, further downstream provides to separate the union strip 20 which is then collected as recyclable material, on a small motor driven spool 65 whilst the filled and detached bags drop into respective packing boxes. If the containers are of the type shown in figs. 1,2,3, i.e., of a type provided with a bottom bellows, the weight of the liquid product introduced in each container will automatically divaricate the external walls causing the bag to remain in an upright position, suitable for display on shop shelves in a vertically stable position. It is obvious that with minimum changes in the filling and sealing stations, the plant may be converted from a step by step type to a continuous type.

Claims: Method for producing containers in flexible material comprising the steps of: a) unwinding a spool of a single or multiple layer band of flexible material having two lateral edges and two opposed surfaces (6, 7), one of the surfaces (6) being a heat-sealable material; b) folding over the lateral edges of the band along respective fold lines to form a folded band having two folded portions each having a transversal width (H) extending between the respective folded over lateral edges and the respective outer edges defined by the respective fold lines, the transversal width (H) being equal to at least a height of an individual container to be produced, the surface of heat-sealable material (6, 6') forming an internal surface of each of the folded portions; c) maintaining a center strip (20) of the flexible material between the folded over lateral edges of the two folded portions; d) forming a series of heat seals (14, 14') transversely along both folded port ions at longitudinal intervals (L), each of the longitudinal intervals being equal to a width of the individual container to be produced, the heat seals (14, 14') forming lateral closing ribs between adjacent pairs of containers and extending from the outer edges of each of the folded portions toward the center strip (20) characterized in that e) the heat seals (14, 14') extending toward the center strip (20) terminate at a short distance (c) before the folded over lateral edges; and further by f) cutting the folded band transversely along a midline (25) of the heat seals (14, 14'), without cutting the center strip (20); g) detaching adjacent containers from each other along the cut midline (25), wherein each of the plurality of pairs of containers remains connected along the edges of the folded portions; and h) collecting the plurality of detached pairs of containers. The method of claim 1, characterized in that the step of collecting (h) comprises winding the band of the plurality of detached pairs of containers on a spool. The method of claim 1, characterized in that the step of collecting (h) comprises folding the plurality of the bands of the detached pairs of containers in an accordion manner into a packing box. The method of claim 1, characterized in that the folded over lateral edges form apertures (2, 4) for the containers along the center strip (20) between the heat seals (14, 14'), the containers of each pair being symmetrically opposed across the center strip (20). The method of claim 1, characterized in that the other surface (7, 7') of the band is a non-heat sealable material. The method of claim 1, characterized in that each of the containers has a bellowed bottom and the band of material originally has a width equal to four times the height (H) of the container plus the width of the center strip (20) plus four times the height (h) of the bellowed bottom of the container. The method of claim 1, characterized by further comprising the step of providing a plurality of perforations (22) or notches (24) along the center strip (20). Apparatus for filling and sealing a plurality of pairs of containers, the apparatus comprising: a) feeding means (47) for delivering a band of a plurality of detached pairs of containers (A, B), the band forming two parallel rows of containers (A, B) separated by the center strip (20); b) a stationary support (42) upstream of the feeding means (47), the center strip (20) of the band resting on the support (42) with the rows (A, B) of containers being vertically suspended from the support (42), each of the containers (A, B) having an aperture (2, 4) which faces upward; c) divaricating means (49) disposed downstream of the feeding means (47) for opening the apertures; d) filling means (48) approximately coinciding with the divaricating means (49) for filling the containers (A, B) with a product, wherein the support (42) extends through the filling (48) and divaricating means (49); e) sealing means (60) for heat sealing the apertures (2, 4) of the containers downstream of the filling means (48); f) means (61) downstream of the sealing means (60) for separating the center strip (20) from the containers (A, B); g) means for recovering the separated center strip (65); and means for collecting the filled and sealed containers. characterized in that the containers (A, B) to be filled are part of a band which is made by: 1) unwinding a spool of a single or multiple layer band of flexible material having two lateral edges and two opposed surfaces (6, 7), one of the surfaces (6) being a heat-sealable material; 2) folding over the lateral edges of the band along respective fold lines to form a folded band having two folded portions each having a transversal width (H) extending between the respective folded over lateral edges and the respective outer edges defined by the respective fold lines, the transversal width (H) being equal to at least a height of an individual container (A or B) to be produced, the surface (6) of heat-sealable material forming an internal surface of each of the folded portions; 3) maintaining a center strip (20) of the flexible material between the folded over lateral edges of the two folded portions; 4) forming a series of heat seals (14, 14') transversely along both the longitudinal intervals (L) being equal to a width of the individual container to be produced, the heat seals (14, 14') forming lateral closing ribs between adjacent pairs of containers and extending from the outer edges of each of the folded portions toward the center strip (20) and terminating at a short distance (c) before the folded over lateral edges; 5) cutting the folded band transversely along a midline (25) of the heat seals (14, 14'), without cutting the center strip (20); 6) detaching adjacent containers from each other along the cut midline (25), wherein each of the plurality of pairs of containers (A, B) remain connected along the edges of the folded portions; and 7) collecting the plurality of detached pairs of containers; wherein h) the means (61) for separating the center strip from the containers are cutting means (61); i) the support (42) widens near the filling means (48) to form a flat support (42) having a width substantially equal to the width (d) of the center strip (20), so that the center strip (20) rests completely flat on the support (42); j) the divaricating means (49) is formed by a section (M) of the flat support (42) which is progressively reduced and widened to provide two arched walls (50, 51), symmetrically concave and facing outwardly; k) the section (M) of the flat support (42) having the arched walls (50, 51) includes a raised back (52) facing upwardly which forces a wall of the containers (A, B) to adhere to one of the arched walls (50, 51) to widen the respective aperture (2, 4). The apparatus of claim 8, characterized in that the center strip (20) includes a plurality of perforations (22), and the feeding means (47) comprises a pinion having teeth which engage said perforations to draw the band toward the filling means (48). The apparatus of claim 8, characterized in that the recovery means (65) comprises a motor driven spool upon which the separated center strip (20) is wound.

Inventors: BOXTEL GERARDUS J M VAN, VAN BOXTEL, G. J. M.
Applicants: CRESCENT HOLDING, CRESCENT HOLDINGS N.V.
Application year: 1990
Main classification: B31B37
IPC codes: B65B43, B31B37