EP3894204A1 - Method and machine for forming flexible bags with special bottom - Google Patents
Method and machine for forming flexible bags with special bottomInfo
- Publication number
- EP3894204A1 EP3894204A1 EP19817711.5A EP19817711A EP3894204A1 EP 3894204 A1 EP3894204 A1 EP 3894204A1 EP 19817711 A EP19817711 A EP 19817711A EP 3894204 A1 EP3894204 A1 EP 3894204A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- wall
- bag
- clamps
- fold
- closed end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B70/00—Making flexible containers, e.g. envelopes or bags
- B31B70/003—Opening or distending bags
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B70/00—Making flexible containers, e.g. envelopes or bags
- B31B70/02—Feeding or positioning sheets, blanks or webs
- B31B70/04—Feeding sheets or blanks
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B70/00—Making flexible containers, e.g. envelopes or bags
- B31B70/26—Folding sheets, blanks or webs
- B31B70/52—Folding sheets, blanks or webs by reciprocating or oscillating members other than plungers and dies, e.g. by fingers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B2150/00—Flexible containers made from sheets or blanks, e.g. from flattened tubes
- B31B2150/001—Flexible containers made from sheets or blanks, e.g. from flattened tubes with square or cross bottom
- B31B2150/0016—Flexible containers made from sheets or blanks, e.g. from flattened tubes with square or cross bottom made from already formed bags
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B2155/00—Flexible containers made from webs
- B31B2155/003—Flexible containers made from webs starting from tubular webs
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
- B31B2160/00—Shape of flexible containers
- B31B2160/20—Shape of flexible containers with structural provision for thickness of contents
Definitions
- the invention relates to a method of forming flexible bags of the kind comprising two walls connected by bellows and closed at one end by a bottom. It also relates to a machine implementing such a method.
- document FR 1 270 400 describes a machine and a process in which a strip is unwound and then formed into a hose.
- the hose is flattened so that it has a first and a second wall, then the hose is sectioned in sections so that at each end of the section remains a tab which extends the first or the second wall.
- the tab is folded and glued by being folded down on the wall other than that from which the tab originates.
- Document FR 786 579 shows several examples of this technique. It shows in particular in FIGS. 4 to 6 a manufacturing process in which the paper strip is provided at regular intervals with lines of transverse perforations, with a line in the center and two lines, offset axially with respect to the central line on each the band.
- the hose is formed by folding each edge over the central part and gluing the two edges between them along a central junction so that that the perforations form two transverse lines offset respectively on one and the other of the faces of the hose.
- the hose thus formed passes between a pair of drive rollers which drive the hose at a constant speed.
- the front part of the hose is gripped by the folding device which includes a drum and a counter-rotating folding roller.
- the drum and the folding roller rotate at a higher peripheral speed than that of the pair of drive rollers.
- the folding roller has a bar capable of gripping the front of the hose against the drum, so that the front part of the hose is pulled and torn apart along the perforations to form a section.
- a rear tab is thus formed on the section, as is a front tab at the end of the hose.
- This front leg will be found on the next section.
- the front tab is folded by the folding device over a glued area to close the front part of the section.
- the roller further comprises a folding blade, placed just behind the bar, which pushes the hose in a clamp carried by the drum so as to fold the hose.
- the hose is formed with bellows which connect the first and the second wall.
- Document WO 2016 097310 A1 shows an example of such bags.
- Document EP 2 864 114 B1 describes an example of a machine implementing such a method.
- a blank is first formed and has two skins connected together along two opposite edges by two bellows. The blank is placed flat on a table, one of the so-called lower skins being against the table, the other skin being on top and the bellows being folded down between the two skins. The blank is driven in translation on the table in a direction parallel to the bellows towards a drum at the periphery of which different stations are distributed.
- First delivery means produce a first fold line at bellows level, and a second fold line at a predetermined mined distance from the first line, in a direction perpendicular to the bellows.
- the discharge means comprise a rotary blade holder and complementary grooves carried by a counter-rotating drum.
- the drum has front gripping means for driving the blank by pinching the front edge of the lower skin.
- the opening roller has suction means which hold the upper skin against the roller after it has passed between it and the drum.
- first lateral pinching means pinch the lateral edge of the blank at the junction between the bellows and the lower skin.
- second pinching means pinch the lateral edge of the blank at the calf of the junction between the bellows and the upper skin.
- the lateral gripping means move away from each other, open the blank and form a fold on the bellows in a radial plane of the drum and the roller.
- the second gripping means release the blank while, following the movement of the drum which drives the blank, spatulas fold the open part towards the center.
- the upper skin folds back at the second fold line.
- second delivery means mark two transverse lines, on either side of the second fold line. One of these lines coincides with the first fold line. Then the two flaps delimited by these fold lines are glued and folded over one another to close the flat bottom and thus form the bag.
- the invention aims to propose a method and a machine for making bags which have the advantage of bags with a square bottom but with production rates close to the production of flat bags.
- the invention relates to a method for forming a flexible bag, the bag comprising a first wall and a second wall superimposed on the first wall, the walls being interconnected along longitudinal edges by two bellows , according to which, successively:
- the first wall is grasped at a predetermined distance from the closed end of the bag by lower clamps mounted on a lower support and the second wall by upper clamps mounted on an upper support and the walls are spread using the clamps,
- the second wall is released by the upper clamps and the closed end is folded down with a reel on the second wall by forming a first fold coming out on the first wall between the lower clamps, a second fold coming out on the second wall between the ends of the ribs, and a third fold returning to the second wall symmetrically at the end of the bag relative to the second fold, thus producing a bottom delimited between the first and the second fold,
- the method being characterized in that during the spacing of the clamps, a rib is formed on the bellows extending from one wall to the other.
- the production of flat bags is followed by a step of forming a special bottom.
- the formation of the ribs creates stiff parts which hold the walls apart before the folding, then when using the bag.
- the bellows fold obliquely on the one hand from the closed end to the ends of the ribs and on the other hand from a fold line internal bellows to the ends of the ribs.
- bags with a rectangular bottom are formed from flat bags. We can thus obtain rates close to those of the production of flat bags with a function similar to that of bags with square bottoms.
- the step of spreading the walls is similar to that in the method of making bags with square bottoms, but it is applied to a bag which is already closed.
- Maintaining the flap is achieved for example by bonding with a meltable adhesive or a solvent adhesive, or by welding when the material is suitable, for example if it is or comprises a thermoplastic material. According to an improvement, it is supported with support means on the second wall after the release of the upper clamps. This facilitates the formation of the third fold by initiating the folding of the second wall on itself.
- a spacing is maintained between the second wall and the first wall over at least part of the width of the bag and over its entire length in order to create an air supply channel from the open end to the closed end.
- the bags closed by the flap are initially formed, they are stacked, then they are unstacked to make the bottom.
- the flat bags can be produced at the optimum rate of the machine that makes them. Stacks of the bags are then taken up, by the number of machines necessary to form the special funds according to the invention.
- the formation of the bottom is carried out in line with the formation of the bag. This avoids the intermediate storage and the unstacking means necessary in the previous embodiment.
- the predetermined distance between the closed end and the first fold, respectively the second fold is substantially equal to the depth of the bellows.
- the bag when open, the bag has flanks formed by the bellows which have the same width as the bottom.
- the invention also relates to a machine for manufacturing flexible bags, the bag comprising a first wall and a second wall superimposed on the first wall, the walls being connected together along longitudinal edges by two bellows, one end of the bag.
- the machine comprising receiving means for receiving in series bags moving in a main direction parallel to the longitudinal edges, the closed end being in front, a lower support for supporting two lower clamps, the lower clamps being arranged for grip the first wall at a predetermined distance from the closed end of the bag, an upper support for supporting upper clamps, the upper clamps being arranged to grip the second wall at a predetermined distance from the closed end of the bag, the support upper and the lower support being arranged to separate the lower clamps from the upper clamps to form a rib on the bellows extending from one wall to the other, a reel to fold the bottom onto the second wall by forming a first fold coming out on the first wall between the lower clips, a second fold coming out on the second wall between the ends of the ribs, and a third fold returning to the second wall symmetrically at the end of the bag relative to the second fold.
- the lower and upper supports are respectively lower and upper counter-rotating cylinders.
- the machine comprises support means for pressing on the second wall after the release of the upper clamps and which include a rule extending in the direction of a generator of the upper cylinder, and actuating means for extracting the rule from the upper cylinder during the folding phase and then retracting it.
- the rule output can be controlled for example by a cam system or by an electric or pneumatic motorized control.
- the reel is produced by a folding cylinder configured to clamp the bag against the lower support. The reel first guides the closed end of the bag towards a neck between it and the first support then tightens the bag at this neck in order to form the folds well, so that the bag is flattened for storage and transport.
- the lower support and / or the upper support comprises suction means for respectively aspirating the first and / or the second wall so as to separate them before gripping by the clamps. This guarantees that the clamps only grip the near wall in order to properly separate the walls.
- the suction means extend upstream of the upper support over a length sufficient to create at least one air supply channel from the open end of the bag to the closed end. These means allow the bag to be filled with air during the separation of the walls at the closed end.
- the suction means comprise a band permeable to air mounted in a loop and against which the second wall of the bag is sucked, the band being driven to pass at the same speed as the bag.
- the band accompanies the movement of the second wall to avoid friction of the latter.
- the strip constitutes one of the walls of a box placed under vacuum, which makes it possible to create the suction through the strip.
- the strip can be perforated at regular intervals.
- the machine comprises a delivery station for marking the walls of the bag according to a first marking at a predetermined distance from the closed end and according to a second marking at the same predetermined distance from the first marking.
- the first marking will then correspond to the first and second fold lines.
- the second marking will correspond to the third fold line.
- the delivery station comprises a delivery cylinder and a counter-cylinder mounted counter-rotating parallel to each other, the delivery cylinder comprising two blades extending along two generators and projecting from the cylinder surface and the counter cylinder having a flexible surface.
- Figure 1 is a schematic side view of a machine according to a first embodiment of the invention.
- Figure 2 is a perspective view of a flat bag before processing according to the method of the invention.
- Figure 3 is a view similar to Figure 2 of the bag having undergone a rib forming step
- Figure 4 is a view similar to Figure 2 of the bag during a folding phase
- Figure 5 is a side view of the bag of Figure 2 at the end of the folding phase
- Figure 6 is a perspective view of the open bag is placed standing near to be filled
- Figure 7 is a view similar to Figure 1 according to a second embodiment
- Figure 8 is a view similar to Figure 2 after completion of the upsetting according to the second embodiment.
- a machine for manufacturing flexible bags comprises a conventional bottom forming station 1 and the detailed description of which is not repeated here.
- a flat bag 2 is provided, the bag 2 comprising, as shown in FIG. 2, a first wall 21 and a second wall 22 superimposed on the first wall 21.
- the walls 21 , 22 are interconnected along longitudinal edges 23 by two bellows 24.
- One end 20 of the bag 2 is closed by a flap 25 from the first wall 21 and glued to the second wall 22.
- the bag 2 is shown with a tongue 26 which extends the first wall 21 beyond the end of the second wall 22 opposite the closed end.
- the invention also applies to the case where the tongue 26 extends the second wall 22, or, more generally, whatever the shape of this end.
- the machine further comprises receiving means 3, a lower support 4, an upper support 5, and a reel 6.
- the receiving means 3 are provided for receiving in series the bags 2 moving in a main direction parallel to the longitudinal edges coming from the bottom forming station 1, the closed end 20 in front.
- the receiving means 3 allow the bags 2 to pass through one by one, at regular intervals until the next step.
- the lower support has the form of a lower cylinder 4 rotatably mounted.
- the lower cylinder 4 supports two lower clamps 41, the lower clamps 41 being arranged to grip the first wall 21 of the bag 2 presented by the receiving means 3 at a predetermined distance from the closed end 20 of the bag 2.
- the lower clamps 41 are aligned on the same generator of the lower cylinder 4.
- the upper support has the shape of an upper cylinder 5 rotatably mounted in the opposite direction to that of the lower cylinder 4.
- the upper cylinder 5 supports upper clamps 51 which are arranged to grip the second wall 22 at the predetermined distance from the closed end 20 of the bag 2. For this, the lower clamps 41 and upper 51 are opposite one another without angular offset.
- the upper clamps 51 are aligned on the same generator of the upper cylinder 5. The gripping of the walls is carried out when the clamps are at the neck between the lower and upper cylinders 4, 5.
- the upper and lower cylinders 4, 5 have suction means 8, for sucking the first and second walls 21, 22 respectively so as to separate them before gripping by the grippers 41, 51.
- These suction means 8 comprise two lower boxes 81 and two upper boxes 82 facing each other upstream of the upper support 5 and, for each box 81, 82, a permeable strip 83, 84 air loop mounted.
- the permeable strip 83, 84 is placed against the box 81, 82 in front of an opening of the latter and is driven to scroll at the same speed as the bag.
- the strip 83, 84 is for example pierced with a row of holes in the middle.
- the box 81, 82 is put under vacuum by means not shown so that the second wall 22 of the bag is sucked against the strip 84 of the upper box 82 and the first wall 21 of the bag is sucked against the strip 83 of the lower box 81
- the length of the boxes 81, 82 is sufficient so that, when the clamps grip the upper and lower walls 21, 22, an air supply channel is created from the open end 21 of the bag to the closed end 20 by the spacing of the walls due to the suction against the strips 83, 84.
- the boxes 81, 82 are placed to vacuum the edges of the walls 21, 22 at the bellows 24.
- the upper support 5 and the lower support 4 are arranged to separate the lower clamps 41 from the upper clamps 51.
- the spacing is obtained by continuing the rotation of the lower and upper cylinders 4, 5 so that the distance between the clamps 41, 51 increases.
- a rib 27 is thus formed on each of the bellows 24 extending from one wall to the other.
- the machine further comprises support means 7 for pressing on the second wall 22 after the upper clamps 51 have been released.
- the support means 7 comprise a rule 71 extending in the direction of a generator of the upper cylinder 5, and actuating means for extracting the rule 71 from the upper cylinder 5 during the folding phase and then retracting it.
- the reel 6 is designed to fold the bottom onto the second wall 22.
- the reel 6 is produced by a folding cylinder 6 configured to clamp the bag 2 against the lower cylinder 4 by being rotated in the opposite direction to the lower cylinder 4.
- the machine implements a process for forming a special bottom on the 2-flat bags.
- the bag 2 After one end of the bag 2 has been closed in the bottom forming station 1 by a flap 25 from one of the walls 21 and glued to the other wall 22, in a manner known per se, the bag 2 is transported in a direction of transport by the receiving means 3, the longitudinal edges 53 of the bag 2 being parallel to the direction of transport F1, towards the neck between the upper and lower cylinders 4, 5, which are counter-rotating.
- the closed end 20 of the bag 2 projects beyond the neck and the suction means tend to separate the first 21 from the second wall 22.
- a channel is created inside the bag along each edge to put in place communication the bottom with the opening of the bag.
- the lower 41 and upper 51 clamps are actuated to grip respectively the first and the second wall 21, 22 at a predetermined distance from the closed end 20 of the bag 2.
- clamps 41, 51 are introduced into the delimited space by the bellows 24. They hold the first wall 21, respectively the second 22, on the lower cylinder 4, respectively upper 5.
- the walls are separated using the clamps 41, 51 to form a rib 27 on the bellows 24 extending from one wall to the other 21 , 22, as shown in Figure 3.
- the cavity thus created is filled with air from the open end through the air supply channels.
- the upper clamps 51 are then controlled to release the second wall 22.
- the rule 71 of the support means 7 is deployed to press on the second wall 22 after the release of the upper clamps 51, as shown in FIG. 4.
- the bag 2 continues its path towards the folding cylinder 6 to fold the closed end 20 of the bag 2 onto the second wall 22 by forming a first fold 281 exiting on the first wall 21 between the lower clamps 41, a second fold 282 exiting on the second wall 22 between the ends of the ribs 27, and a third fold 283 returning to the second wall 22 symmetrically at the end of the bag 2 relative to the second fold 282, thus producing a bottom 29 delimited between the first and the second fold 281, 282.
- the distance between the closed end 20 and the first fold 281, respectively the second fold 282 is substantially equal to the depth of the bellows 24.
- the bag 2 When using the bag 2, it can be opened by the open end, spreading the first and second walls 21, 22, to obtain a shape as in FIG. 6. Depending on the nature of the material of the bag 2, it can stand upright on the bottom 29 created by the method.
- the material may be paper, plastic film or a woven material of thermoplastic material.
- the bags closed by the flap 25 are initially formed, they are stacked, then they are unstacked to make the bottom 29. Unstacking means replace the bottom forming station 1 and feeds the receiving means 3 with the bags one by one.
- the machine differs from that of the first embodiment in that it comprises a delivery station 9 to mark the walls of the bag and facilitate the setting form of it.
- the discharge station 9 is placed upstream of the suction means 8 and comprises a discharge cylinder 91 and a counter-cylinder 91.
- the two cylinders 91, 92 are rotatably mounted parallel to one another and are counter-rotating.
- the discharge cylinder 91 has two blades 911, 912 extending along two generators and projecting from the surface of the cylinder 91.
- the counter-cylinder 92 has a flexible surface, produced for example by a rubber coating, at least opposite blades 911, 912.
- the peripheral speed of the cylinders 91, 92 is that of movement of the bags.
- the blades 911, 912 successively pinch the bag 2 against the counter-cylinder 92 and thus carry out two markings on each bag.
- the first marking corresponds to the first fold 281 and to the second fold 282, while the second marking anticipates the third fold 283, as shown in FIG. 8.
- the preferential distance between the first marking and the edge of the closed end is equal to the depth of the bellows.
- the preferred distance between the second marking and the edge of the closed end is twice the depth of the bellows.
Landscapes
- Making Paper Articles (AREA)
Abstract
A flexible bag (2) comprises a first wall (21) and a second wall (22) superimposed on the first wall (21), the walls (21, 22) being connected together along longitudinal edges (53) by two bellows (24). According to a method for forming the bag (2), successively: - closing the bag (2) by a flap (25) originating from one of the walls (21) and held on the other wall (22) in order to form a closed end (20) of the bag (2), - grasping, at a predetermined distance from the closed end (20) of the bag (2), the first wall (21) by lower clamps (41) and the second wall (22) by upper clamps (51) and moving apart the walls in order to form a rib (27) on the bellows (24), - releasing of the second wall (22) by the upper clamps (51) and folding down (25), using a reel (6), the closed end (20) on the second wall (22), thus producing a bottom (29). The invention also concerns a machine implementing said method.
Description
PROCÉDÉ ET MACHINE DE FORMATION DE SACS FLEXIBLES À FOND METHOD AND MACHINE FOR FORMING BOTTOM FLEXIBLE BAGS
SPÉCIAL SPECIAL
DOMAINE DE L’INVENTION FIELD OF THE INVENTION
L’invention concerne un procédé de formation de sacs flexibles du genre comportant deux parois reliées par des soufflets et fermés à une extrémité par un fond. Elle concerne également une machine mettant en oeuvre un tel procédé. The invention relates to a method of forming flexible bags of the kind comprising two walls connected by bellows and closed at one end by a bottom. It also relates to a machine implementing such a method.
ART ANTÉRIEUR PRIOR ART
On connaît depuis longtemps des procédés industriels de fabrication de sacs en matière flexible telle que du papier ou de la matière synthétique. Par exemple, le document FR 1 270 400 décrit une machine et un procédé dans lequel une bande est déroulée puis formée en boyau. Le boyau est aplati de telle sorte qu’il comporte une première et une deuxième paroi, puis le boyau est sectionné en tronçon de telle sorte qu’à chaque extrémité du tronçon subsiste une patte qui prolonge la première ou la deuxième paroi. Dans une étape de pliage, la patte est pliée et collée en étant rabattue sur la paroi autre que celle dont la patte est issue. On peut ainsi fabriquer des sacs à une grande cadence avec une grande variété de matières et de formats. Le document FR 786 579 montre plusieurs exemples de cette technique. Il montre en particulier sur les figures 4 à 6 un procédé de fabrication dans lequel la bande de papier est munie à intervalles réguliers de lignes de perforations transversales, avec une ligne au centre et deux lignes, décalées axialement par rapport à la ligne centrale sur chaque lé de la bande. Industrial processes for manufacturing bags made of flexible material such as paper or synthetic material have long been known. For example, document FR 1 270 400 describes a machine and a process in which a strip is unwound and then formed into a hose. The hose is flattened so that it has a first and a second wall, then the hose is sectioned in sections so that at each end of the section remains a tab which extends the first or the second wall. In a folding step, the tab is folded and glued by being folded down on the wall other than that from which the tab originates. We can thus manufacture bags at a high rate with a wide variety of materials and formats. Document FR 786 579 shows several examples of this technique. It shows in particular in FIGS. 4 to 6 a manufacturing process in which the paper strip is provided at regular intervals with lines of transverse perforations, with a line in the center and two lines, offset axially with respect to the central line on each the band.
Le boyau est formé en repliant chaque bord par-dessus la partie centrale et en collant entre eux les deux bords le long d’une jonction centrale de telle sorte
que les perforations forment deux lignes transversales décalées respectivement sur l’une et l’autre des faces du boyau. Le boyau ainsi formé passe entre une paire de galets d’entraînement qui entraînent le boyau à une vitesse constante. La partie avant du boyau est saisie par le dispositif de pliage qui comporte un tambour et un rouleau de pliage contrarotatifs. Le tambour et le rouleau de pliage tournent avec une vitesse périphérique supérieure à celle de la paire de galets d’entraînement. Le rouleau de pliage comporte une barre apte à pincer l’avant du boyau contre le tambour, de telle sorte que la partie avant du boyau est tirée et séparée par déchirement le long des perforations pour former un tronçon. A la séparation, du fait des décalages entre les lignes de perforation, une patte arrière est ainsi formée sur le tronçon, de même qu’une patte avant à l’extrémité du boyau. Cette patte avant se retrouvera sur le tronçon suivant. La patte avant est repliée par le dispositif de pliage sur une zone encollée pour fermer la partie avant du tronçon. Pour cela, le rouleau comporte en outre une lame de pliage, placée juste en arrière de la barre, qui pousse le boyau dans une pince portée par le tambour de manière à plier le boyau. The hose is formed by folding each edge over the central part and gluing the two edges between them along a central junction so that that the perforations form two transverse lines offset respectively on one and the other of the faces of the hose. The hose thus formed passes between a pair of drive rollers which drive the hose at a constant speed. The front part of the hose is gripped by the folding device which includes a drum and a counter-rotating folding roller. The drum and the folding roller rotate at a higher peripheral speed than that of the pair of drive rollers. The folding roller has a bar capable of gripping the front of the hose against the drum, so that the front part of the hose is pulled and torn apart along the perforations to form a section. On separation, due to the offsets between the perforation lines, a rear tab is thus formed on the section, as is a front tab at the end of the hose. This front leg will be found on the next section. The front tab is folded by the folding device over a glued area to close the front part of the section. For this, the roller further comprises a folding blade, placed just behind the bar, which pushes the hose in a clamp carried by the drum so as to fold the hose.
Dans une variante, le boyau est formé avec des soufflets qui relient la première et la deuxième paroi. Le document WO 2016 097310 Al montre un exemple de tels sacs. On connaît aussi un procédé de fabrication de sacs à fond carré qui ont l’avantage de pouvoir être dressés sur le fond et rester ouverts et debout plus facilement. Le document EP 2 864 114 B1 décrit un exemple de machine mettant en oeuvre un tel procédé. Dans cet exemple, une ébauche est d’abord formée et présente deux peaux reliées entre elles le long de deux bords opposés par deux soufflets. L’ébauche est posée à plat sur une table, l’une des peaux dite inférieure étant contre la table, l’autre peau étant par dessus et les soufflets étant rabattus entre les deux peaux. L’ébauche est entraînée en translation sur la table dans une direction parallèle aux soufflets vers un tambour en périphérie duquel différentes stations sont réparties. In a variant, the hose is formed with bellows which connect the first and the second wall. Document WO 2016 097310 A1 shows an example of such bags. There is also known a method of manufacturing bags with a square bottom which have the advantage of being able to be drawn up on the bottom and to remain open and standing more easily. Document EP 2 864 114 B1 describes an example of a machine implementing such a method. In this example, a blank is first formed and has two skins connected together along two opposite edges by two bellows. The blank is placed flat on a table, one of the so-called lower skins being against the table, the other skin being on top and the bellows being folded down between the two skins. The blank is driven in translation on the table in a direction parallel to the bellows towards a drum at the periphery of which different stations are distributed.
Des premiers moyens de refoulage réalisent une première ligne de pliage au
niveau des soufflets, et une deuxième ligne de pliage à une distance prédéter minée de la première ligne, dans une direction perpendiculaire aux soufflets. Les moyens de refoulage comportent un porte-lame rotatif et des rainures com plémentaires portées par un tambour contrarotatif. En progressant, l’avant de l’ébauche est happé entre le tambour et un rouleau. Le tambour comporte des moyens de pincement avant pour entraîner l’ébauche en pinçant le bord avant de la peau inférieure. Pour faciliter la séparation des deux peaux, le rou leau d’ouverture comporte des moyens d’aspiration qui maintiennent la peau supérieure contre le rouleau après son passage entre celui-ci et le tambour. En retrait par rapport aux moyens de pincement avant, des premiers moyens de pincement latéraux pincent le bord latéral de l’ébauche au niveau de la jonction entre le soufflet et la peau inférieure. De manière symétrique, des deuxièmes moyens de pincement pincent le bord latéral de l’ébauche au ni veau de la jonction entre le soufflet et la peau supérieure. Lorsque l’ébauche poursuit son passage entre le rouleau et le tambour, les moyens de pincement latéraux s’écartent les uns des autres, ouvrent l’ébauche et forment un pli sur le soufflet dans un plan radial du tambour et du rouleau. Les deuxièmes moyens de pincement relâchent l’ébauche tandis que dans la suite du mouvement du tambour qui entraîne l’ébauche, des spatules rabattent la partie ouverte vers le centre. La peau supérieure se plie vers l’arrière au niveau de la deuxième ligne de pliage. Dans la suite des opérations, des deuxièmes moyens de refoulage marquent deux lignes transversales, de part et d’autre de la deuxième ligne de pliage. L’une de ces lignes coïncide avec la première ligne de pliage. Ensuite les deux rabats délimités par ces lignes de pliage sont encollés et rabattus l’un sur l’autre pour fermer le fond plat et former ainsi le sac. First delivery means produce a first fold line at bellows level, and a second fold line at a predetermined mined distance from the first line, in a direction perpendicular to the bellows. The discharge means comprise a rotary blade holder and complementary grooves carried by a counter-rotating drum. As it progresses, the front of the blank is caught between the drum and a roller. The drum has front gripping means for driving the blank by pinching the front edge of the lower skin. To facilitate the separation of the two skins, the opening roller has suction means which hold the upper skin against the roller after it has passed between it and the drum. Set back from the front pinching means, first lateral pinching means pinch the lateral edge of the blank at the junction between the bellows and the lower skin. Symmetrically, second pinching means pinch the lateral edge of the blank at the calf of the junction between the bellows and the upper skin. When the blank continues to pass between the roller and the drum, the lateral gripping means move away from each other, open the blank and form a fold on the bellows in a radial plane of the drum and the roller. The second gripping means release the blank while, following the movement of the drum which drives the blank, spatulas fold the open part towards the center. The upper skin folds back at the second fold line. In the following operations, second delivery means mark two transverse lines, on either side of the second fold line. One of these lines coincides with the first fold line. Then the two flaps delimited by these fold lines are glued and folded over one another to close the flat bottom and thus form the bag.
Les opérations de fabrication d’un tel sac sont bien plus complexes que celles d’un sac plat de telle sorte que les cadences de production sont bien plus limitées. The manufacturing operations of such a bag are much more complex than those of a flat bag so that the production rates are much more limited.
OBJECTIFS DE L’INVENTION
Pour résoudre ces problèmes, l’invention vise à proposer un procédé et une machine de fabrication de sacs qui aient l’avantage des sacs à fond carré mais avec des cadences de production proches de la fabrication des sacs plats. OBJECTIVES OF THE INVENTION To solve these problems, the invention aims to propose a method and a machine for making bags which have the advantage of bags with a square bottom but with production rates close to the production of flat bags.
DESCRIPTION DE L’INVENTION DESCRIPTION OF THE INVENTION
Avec ces objectifs en vue, l’invention a pour objet un procédé de formation de sac flexible, le sac comportant une première paroi et une deuxième paroi superposée à la première paroi, les parois étant reliées entre elles le long de bords longitudinaux par deux soufflets, selon lequel, successivement : With these objectives in view, the invention relates to a method for forming a flexible bag, the bag comprising a first wall and a second wall superimposed on the first wall, the walls being interconnected along longitudinal edges by two bellows , according to which, successively:
> on ferme le sac pour former une extrémité fermée du sac à l’opposé d’une extrémité ouverte, > we close the bag to form a closed end of the bag opposite an open end,
on saisit à une distance prédéterminée de l’extrémité fermée du sac la première paroi par des pinces inférieures montées sur un support inférieur et la deuxième paroi par des pinces supérieures montées sur un support supérieur et on écarte les parois à l’aide des pinces, the first wall is grasped at a predetermined distance from the closed end of the bag by lower clamps mounted on a lower support and the second wall by upper clamps mounted on an upper support and the walls are spread using the clamps,
on lâche la deuxième paroi par les pinces supérieures et on rabat avec un rabatteur l’extrémité fermée sur la deuxième paroi en formant un premier pli sortant sur la première paroi entre les pinces inférieures, un deuxième pli sortant sur la deuxième paroi entre les extrémités des côtes, et un troisième pli rentrant sur la deuxième paroi symétriquement à l’extrémité du sac par rapport au deuxième pli, réalisant ainsi un fond délimité entre le premier et le deuxième pli, the second wall is released by the upper clamps and the closed end is folded down with a reel on the second wall by forming a first fold coming out on the first wall between the lower clamps, a second fold coming out on the second wall between the ends of the ribs, and a third fold returning to the second wall symmetrically at the end of the bag relative to the second fold, thus producing a bottom delimited between the first and the second fold,
le procédé étant caractérisé en ce que lors de l’écartement des pinces, on forme une côte sur les soufflets s’étendant d’une paroi à l’autre. the method being characterized in that during the spacing of the clamps, a rib is formed on the bellows extending from one wall to the other.
Ainsi, on fait succéder à la fabrication de sacs plats une étape de formation d’un fond spécial. La formation des côtes crée des parties raides qui main tiennent les parois écartées avant le rabattement, puis lors de l’utilisation du sac. Naturellement, les soufflets se plient en biais d’une part depuis l’extrémité fermée jusqu’aux extrémités des côtes et d’autre part depuis une ligne de pli
interne des soufflets jusqu’aux extrémités des côtes. Grâce à ce procédé, on forme des sacs ayant un fond de forme rectangulaire à partir de sacs plats. On peut ainsi obtenir des cadences proches de celles de la fabrication de sacs plats avec une fonction similaire à celle des sacs à fonds carrés. L’étape d’écarte- ment des parois est similaire à celle dans le procédé de fabrication des sacs à fonds carrés, mais elle est appliquée à un sac qui est déjà fermé. Le maintien du rabat est réalisé par exemple par collage avec une colle fusible ou une colle à solvant, ou par soudure lorsque le matériau s’y prête, par exemple s’il est ou comprend une matière thermoplastique. Selon un perfectionnement, on appuie avec des moyens d’appui sur la deuxième paroi après le relâchement des pinces supérieures. On facilite ainsi la formation du troisième pli en amorçant le rabattement de la deuxième paroi sur elle-même. Thus, the production of flat bags is followed by a step of forming a special bottom. The formation of the ribs creates stiff parts which hold the walls apart before the folding, then when using the bag. Naturally, the bellows fold obliquely on the one hand from the closed end to the ends of the ribs and on the other hand from a fold line internal bellows to the ends of the ribs. Using this method, bags with a rectangular bottom are formed from flat bags. We can thus obtain rates close to those of the production of flat bags with a function similar to that of bags with square bottoms. The step of spreading the walls is similar to that in the method of making bags with square bottoms, but it is applied to a bag which is already closed. Maintaining the flap is achieved for example by bonding with a meltable adhesive or a solvent adhesive, or by welding when the material is suitable, for example if it is or comprises a thermoplastic material. According to an improvement, it is supported with support means on the second wall after the release of the upper clamps. This facilitates the formation of the third fold by initiating the folding of the second wall on itself.
Selon un perfectionnement, on maintient un écartement entre la deuxième paroi et la première paroi sur au moins une partie de la largeur du sac et sur toute sa longueur afin de créer un canal d’alimentation en air depuis l’extrémité ouverte jusqu’à l’extrémité fermée. Ainsi lorsque l’on écarte la première paroi de la deuxième paroi, et qu’ainsi on crée une cavité au niveau de l’extrémité fermée du sac, de l’air peut venir emplir la cavité en passant par le canal d’alimentation. On évite ainsi de limiter la cadence du fait de la durée de remplissage trop longue si les parois restaient superposées. According to an improvement, a spacing is maintained between the second wall and the first wall over at least part of the width of the bag and over its entire length in order to create an air supply channel from the open end to the closed end. When the first wall is moved away from the second wall, and a cavity is created at the closed end of the bag, air can fill the cavity through the supply channel. This avoids limiting the rate due to the too long filling time if the walls remained superimposed.
Selon un mode de réalisation, on forme initialement les sacs fermés par le rabat, on les empile, puis on les dépile pour réaliser le fond. On peut réaliser les sacs plats à la cadence optimale de la machine qui les fabrique. Des piles des sacs sont ensuite reprises, par le nombre de machines nécessaires pour former les fonds spéciaux selon l’invention. According to one embodiment, the bags closed by the flap are initially formed, they are stacked, then they are unstacked to make the bottom. The flat bags can be produced at the optimum rate of the machine that makes them. Stacks of the bags are then taken up, by the number of machines necessary to form the special funds according to the invention.
Selon un autre mode de réalisation, la formation du fond est réalisée en ligne avec la formation du sac. On évite ainsi le stockage intermédiaire et les moyens de dépilage nécessaire dans le mode de réalisation précédant.
Selon une caractéristique géométrique, la distance prédéterminée entre l’ex trémité fermée et le premier pli, respectivement le deuxième pli est sensiblement égale à la profondeur des soufflets. Ainsi, lorsqu’il est ouvert, le sac comporte des flancs formés par les soufflets qui ont la même largeur que le fond . L’invention a aussi pour objet une machine de fabrication de sacs flexibles, le sac comportant une première paroi et une deuxième paroi superposée à la première paroi, les parois étant reliées entre elles le long de bords longitudinaux par deux soufflets, une extrémité du sac étant fermée, la machine comportant des moyens de réception pour recevoir en série des sacs se déplaçant dans une direction principale parallèle aux bords longitudinaux, l’extrémité fermée étant en avant, un support inférieur pour supporter deux pinces inférieures, les pinces inférieures étant agencées pour saisir la première paroi à une distance prédéterminée de l’extrémité fermée du sac, un support supérieur pour suppor ter des pinces supérieures, les pinces supérieures étant agencées pour saisir la deuxième paroi à une distance prédéterminée de l’extrémité fermée du sac, le support supérieur et le support inférieur étant agencés pour écarter les pinces inférieures des pinces supérieures pour former une côte sur les soufflets s’éten dant d’une paroi à l’autre, un rabatteur pour rabattre le fond sur la deuxième paroi en formant un premier pli sortant sur la première paroi entre les pinces inférieures, un deuxième pli sortant sur la deuxième paroi entre les extrémités des côtes, et un troisième pli rentrant sur la deuxième paroi symétriquement à l’extrémité du sac par rapport au deuxième pli. According to another embodiment, the formation of the bottom is carried out in line with the formation of the bag. This avoids the intermediate storage and the unstacking means necessary in the previous embodiment. According to a geometric characteristic, the predetermined distance between the closed end and the first fold, respectively the second fold is substantially equal to the depth of the bellows. Thus, when open, the bag has flanks formed by the bellows which have the same width as the bottom. The invention also relates to a machine for manufacturing flexible bags, the bag comprising a first wall and a second wall superimposed on the first wall, the walls being connected together along longitudinal edges by two bellows, one end of the bag. being closed, the machine comprising receiving means for receiving in series bags moving in a main direction parallel to the longitudinal edges, the closed end being in front, a lower support for supporting two lower clamps, the lower clamps being arranged for grip the first wall at a predetermined distance from the closed end of the bag, an upper support for supporting upper clamps, the upper clamps being arranged to grip the second wall at a predetermined distance from the closed end of the bag, the support upper and the lower support being arranged to separate the lower clamps from the upper clamps to form a rib on the bellows extending from one wall to the other, a reel to fold the bottom onto the second wall by forming a first fold coming out on the first wall between the lower clips, a second fold coming out on the second wall between the ends of the ribs, and a third fold returning to the second wall symmetrically at the end of the bag relative to the second fold.
Selon une disposition constructive, les supports inférieur et supérieur sont des cylindres contrarotatifs respectivement inférieur et supérieur. Une fois que les pinces ont passé le col entre les cylindres, les pinces s’éloignent les unes des autres du fait de la rotation des cylindres. Après une rotation complète, les pinces retrouvent une position pour prendre en charge le sac suivant. According to a constructive arrangement, the lower and upper supports are respectively lower and upper counter-rotating cylinders. Once the pliers have passed the neck between the cylinders, the pliers move away from each other due to the rotation of the cylinders. After a complete rotation, the clamps find a position to take over the next bag.
Selon un perfectionnement, la machine comporte des moyens d’appui pour appuyer sur la deuxième paroi après le relâchement des pinces supérieures et qui comportent une règle s’étendant selon la direction d’une génératrice du
cylindre supérieur, et des moyens d’actionnement pour extraire la règle du cylindre supérieur pendant la phase de rabattement et la rétracter ensuite. La sortie de la règle peut être commandée par exemple par un système à came ou par une commande à motorisation électrique ou pneumatique. Selon une disposition constructive, le rabatteur est réalisé par un cylindre de rabattement configuré pour serrer le sac contre le support inférieur. Le rabatteur guide d’abord l’extrémité fermée du sac vers un col entre lui et le premier support puis serre le sac au niveau de ce col afin de bien former les plis, de telle sorte que le sac est aplati pour le stockage et le transport. Selon un perfectionnement, le support inférieur et/ou le support supérieur comporte des moyens d’aspiration pour aspirer respectivement la première et/ou la deuxième paroi de manière à les séparer avant la saisie par les pinces. On garantit ainsi que les pinces ne saisissent que la paroi proche afin de bien séparer les parois. Selon un perfectionnement, les moyens d’aspiration s’étendent en amont du support supérieur sur une longueur suffisante pour créer au moins un canal d’alimentation en air depuis l’extrémité ouverte du sac jusqu’à l’extrémité fer mée. Ces moyens permettent le remplissage en air du sac lors de l’écartement des parois à l’extrémité fermée. Selon une disposition constructive, les moyens d’aspiration comportent une bande perméable à l’air montée en boucle et contre laquelle la deuxième paroi du sac est aspirée, la bande étant entraînée pour défiler à la même vitesse que le sac. La bande accompagne le déplacement de la deuxième paroi pour éviter le frottement de celle-ci. La bande constitue l’une des parois d’un caisson mis en dépression, ce qui permet de créer l’aspiration à travers la bande. Pour créer la perméabilité, la bande peut être perforée à intervalles réguliers. According to an improvement, the machine comprises support means for pressing on the second wall after the release of the upper clamps and which include a rule extending in the direction of a generator of the upper cylinder, and actuating means for extracting the rule from the upper cylinder during the folding phase and then retracting it. The rule output can be controlled for example by a cam system or by an electric or pneumatic motorized control. According to a constructive arrangement, the reel is produced by a folding cylinder configured to clamp the bag against the lower support. The reel first guides the closed end of the bag towards a neck between it and the first support then tightens the bag at this neck in order to form the folds well, so that the bag is flattened for storage and transport. According to an improvement, the lower support and / or the upper support comprises suction means for respectively aspirating the first and / or the second wall so as to separate them before gripping by the clamps. This guarantees that the clamps only grip the near wall in order to properly separate the walls. According to an improvement, the suction means extend upstream of the upper support over a length sufficient to create at least one air supply channel from the open end of the bag to the closed end. These means allow the bag to be filled with air during the separation of the walls at the closed end. According to a constructive arrangement, the suction means comprise a band permeable to air mounted in a loop and against which the second wall of the bag is sucked, the band being driven to pass at the same speed as the bag. The band accompanies the movement of the second wall to avoid friction of the latter. The strip constitutes one of the walls of a box placed under vacuum, which makes it possible to create the suction through the strip. To create permeability, the strip can be perforated at regular intervals.
Selon un perfectionnement, la machine comporte une station de refoulage pour marquer les parois du sac selon un premier marquage à une distance pré déterminée de l’extrémité fermée et selon un deuxième marquage à la même
distance prédéterminée du premier marquage. Le premier marquage correspon dra ensuite à la première et la deuxième ligne de pliage. Le deuxième marquage correspondra à la troisième ligne de pliage. En marquant par avance les lignes de pliage, on facilite la formation desdits plis. On s’assure également de la position desdites lignes de pliage. According to an improvement, the machine comprises a delivery station for marking the walls of the bag according to a first marking at a predetermined distance from the closed end and according to a second marking at the same predetermined distance from the first marking. The first marking will then correspond to the first and second fold lines. The second marking will correspond to the third fold line. By marking the fold lines in advance, it facilitates the formation of said folds. We also ensure the position of said fold lines.
Selon une disposition constructive, la station de refoulage comporte un cylindre de refoulage et un contre-cylindre montés contrarotatifs parallèlement l’un à l’autre, le cylindre de refoulage comportant deux lames s’étendant le long de deux génératrices et faisant saillie de la surface du cylindre et le contre- cylindre comportant une surface souple. According to a constructive arrangement, the delivery station comprises a delivery cylinder and a counter-cylinder mounted counter-rotating parallel to each other, the delivery cylinder comprising two blades extending along two generators and projecting from the cylinder surface and the counter cylinder having a flexible surface.
DESCRIPTION DES FIGURES DESCRIPTION OF THE FIGURES
D’autres caractéristiques et avantages de l’invention ressortiront clairement de la description qui en est faite ci-après, à titre indicatif et nullement limitatif, en référence aux dessins annexés parmi lesquels : Other characteristics and advantages of the invention will emerge clearly from the description which is given below, for information and in no way limitative, with reference to the appended drawings among which:
> la figure 1 est une vue schématique de côté d’une machine selon un premier mode de réalisation de l’invention ; > Figure 1 is a schematic side view of a machine according to a first embodiment of the invention;
> la figure 2 est une vue en perspective d’un sac plat avant la transformation selon le procédé de l’invention ; > Figure 2 is a perspective view of a flat bag before processing according to the method of the invention;
la figure 3 est une vue similaire à la figure 2 du sac ayant subi une étape de formation des côtes ; Figure 3 is a view similar to Figure 2 of the bag having undergone a rib forming step;
> la figure 4 est une vue similaire à la figure 2 du sac pendant une phase de rabattement ; > Figure 4 is a view similar to Figure 2 of the bag during a folding phase;
la figure 5 est une vue de côté du sac de la figure 2 à la fin de la phase de rabattement ; Figure 5 is a side view of the bag of Figure 2 at the end of the folding phase;
la figure 6 est une vue en perspective du sac ouvert est posé debout près à être rempli Figure 6 is a perspective view of the open bag is placed standing near to be filled
> la figure 7 est une vue similaire à la figure 1 selon un deuxième mode de réalisation
la figure 8 est une vue similaire à la figure 2 après la réalisation du refoulage selon le deuxième mode de réalisation. > Figure 7 is a view similar to Figure 1 according to a second embodiment Figure 8 is a view similar to Figure 2 after completion of the upsetting according to the second embodiment.
DESCRIPTION DÉTAILLÉE DETAILED DESCRIPTION
Une machine de fabrication de sacs flexibles, selon un premier mode de réalisation et telle que représentée schématiquement sur la figure 1, comporte une station de formation de fond 1 classique et dont la description détaillée n’est pas reprise ici. A la sortie de la station de formation de fond 1, un sac 2 plat est fourni, le sac 2 comportant, comme montré sur la figure 2, une première paroi 21 et une deuxième paroi 22 superposée à la première paroi 21. Les parois 21, 22 sont reliées entre elles le long de bords longitudinaux 23 par deux soufflets 24. Une extrémité 20 du sac 2 est fermée par un rabat 25 issu de la première paroi 21 et collé sur la deuxième paroi 22. Le sac 2 est représenté avec une languette 26 qui prolonge la première paroi 21 au- delà de l’extrémité de la deuxième paroi 22 à l’opposé de l’extrémité fermée. Cependant, l’invention s’applique également au cas où la languette 26 prolonge la deuxième paroi 22, ou, d’une manière plus générale, quelle que soit la forme de cette extrémité. A machine for manufacturing flexible bags, according to a first embodiment and as shown diagrammatically in FIG. 1, comprises a conventional bottom forming station 1 and the detailed description of which is not repeated here. At the exit from the bottom forming station 1, a flat bag 2 is provided, the bag 2 comprising, as shown in FIG. 2, a first wall 21 and a second wall 22 superimposed on the first wall 21. The walls 21 , 22 are interconnected along longitudinal edges 23 by two bellows 24. One end 20 of the bag 2 is closed by a flap 25 from the first wall 21 and glued to the second wall 22. The bag 2 is shown with a tongue 26 which extends the first wall 21 beyond the end of the second wall 22 opposite the closed end. However, the invention also applies to the case where the tongue 26 extends the second wall 22, or, more generally, whatever the shape of this end.
La machine comporte en outre des moyens de réception 3, un support inférieur 4, un support supérieur 5, et un rabatteur 6. The machine further comprises receiving means 3, a lower support 4, an upper support 5, and a reel 6.
Les moyens de réception 3 sont prévus pour recevoir en série les sacs 2 se déplaçant dans une direction principale parallèle aux bords longitudinaux en provenance de la station de formation de fond 1, l’extrémité fermée 20 en avant. Les moyens de réception 3 permettent de faire transiter les sacs 2 un par un, à intervalle régulier jusqu’à l’étape suivante. The receiving means 3 are provided for receiving in series the bags 2 moving in a main direction parallel to the longitudinal edges coming from the bottom forming station 1, the closed end 20 in front. The receiving means 3 allow the bags 2 to pass through one by one, at regular intervals until the next step.
Le support inférieur a la forme d’un cylindre inférieur 4 monté rotatif. Le cylindre inférieur 4 supporte deux pinces inférieures 41, les pinces inférieures 41 étant agencées pour saisir la première paroi 21 du sac 2 présenté par les moyens de réception 3 à une distance prédéterminée de l’extrémité fermée 20
du sac 2. Les pinces inférieures 41 sont alignées sur une même génératrice du cylindre inférieur 4. Le support supérieur a la forme d’un cylindre supérieur 5 monté rotatif dans le sens inverse à celui du cylindre inférieur 4. Le cylindre supérieur 5 supporte des pinces supérieures 51 qui sont agencées pour saisir la deuxième paroi 22 à la distance prédéterminée de l’extrémité fermée 20 du sac 2. Pour cela, les pinces inférieures 41 et supérieures 51 sont en regard les unes des autres sans décalage angulaire. Les pinces supérieures 51 sont alignées sur une même génératrice du cylindre supérieur 5. La saisie des parois est effectuée lorsque les pinces sont au niveau du col entre les cylindres inférieur et supérieur 4, 5. The lower support has the form of a lower cylinder 4 rotatably mounted. The lower cylinder 4 supports two lower clamps 41, the lower clamps 41 being arranged to grip the first wall 21 of the bag 2 presented by the receiving means 3 at a predetermined distance from the closed end 20 of the bag 2. The lower clamps 41 are aligned on the same generator of the lower cylinder 4. The upper support has the shape of an upper cylinder 5 rotatably mounted in the opposite direction to that of the lower cylinder 4. The upper cylinder 5 supports upper clamps 51 which are arranged to grip the second wall 22 at the predetermined distance from the closed end 20 of the bag 2. For this, the lower clamps 41 and upper 51 are opposite one another without angular offset. The upper clamps 51 are aligned on the same generator of the upper cylinder 5. The gripping of the walls is carried out when the clamps are at the neck between the lower and upper cylinders 4, 5.
Pour faciliter la saisie par les pinces 41, 51, les cylindres supérieur et inférieur 4, 5 comportent des moyens d’aspiration 8, pour aspirer respectivement la première et la deuxième paroi 21, 22 de manière à les séparer avant la saisie par les pinces 41, 51. Ces moyens d’aspiration 8 comportent deux caissons inférieurs 81 et deux caissons supérieurs 82 en regard l’un de l’autre en amont du support supérieur 5 et, pour chaque caisson 81, 82, une bande 83, 84 perméable à l’air montée en boucle. La bande 83, 84 perméable est placée contre le caisson 81, 82 devant une ouverture de celui-ci et est entraînée pour défiler à la même vitesse que le sac. La bande 83, 84 est par exemple percée d’une rangée de trous en son milieu. Le caisson 81, 82 est mis sous dépression par des moyens non représentés de sorte que la deuxième paroi 22 du sac est aspirée contre la bande 84 du caisson supérieur 82 et la première paroi 21 du sac est aspirée contre la bande 83 du caisson inférieur 81. La longueur des caissons 81, 82 est suffisante pour que, lorsque les pinces saisissent les parois supérieure et inférieure 21, 22, un canal d’alimentation en air soit créé depuis l’extrémité ouverte 21 du sac jusqu’à l’extrémité fermée 20 par l’écartement des parois dû à l’aspiration contre les bandes 83, 84. De préférence, les caissons 81, 82 sont placés pour aspirer les bords des parois 21, 22 au niveau des soufflets 24. To facilitate gripping by the clamps 41, 51, the upper and lower cylinders 4, 5 have suction means 8, for sucking the first and second walls 21, 22 respectively so as to separate them before gripping by the grippers 41, 51. These suction means 8 comprise two lower boxes 81 and two upper boxes 82 facing each other upstream of the upper support 5 and, for each box 81, 82, a permeable strip 83, 84 air loop mounted. The permeable strip 83, 84 is placed against the box 81, 82 in front of an opening of the latter and is driven to scroll at the same speed as the bag. The strip 83, 84 is for example pierced with a row of holes in the middle. The box 81, 82 is put under vacuum by means not shown so that the second wall 22 of the bag is sucked against the strip 84 of the upper box 82 and the first wall 21 of the bag is sucked against the strip 83 of the lower box 81 The length of the boxes 81, 82 is sufficient so that, when the clamps grip the upper and lower walls 21, 22, an air supply channel is created from the open end 21 of the bag to the closed end 20 by the spacing of the walls due to the suction against the strips 83, 84. Preferably, the boxes 81, 82 are placed to vacuum the edges of the walls 21, 22 at the bellows 24.
Le support supérieur 5 et le support inférieur 4 sont agencés pour écarter les pinces inférieures 41 des pinces supérieures 51. L’écartement est obtenu par
la poursuite de la rotation des cylindres inférieur et supérieur 4, 5 de sorte que la distance entre les pinces 41, 51 augmente. On forme ainsi une côte 27 sur chacun des soufflets 24 s’étendant d’une paroi à l’autre. The upper support 5 and the lower support 4 are arranged to separate the lower clamps 41 from the upper clamps 51. The spacing is obtained by continuing the rotation of the lower and upper cylinders 4, 5 so that the distance between the clamps 41, 51 increases. A rib 27 is thus formed on each of the bellows 24 extending from one wall to the other.
La machine comporte en outre des moyens d’appui 7 pour appuyer sur la deuxième paroi 22 après le relâchement des pinces supérieures 51. Les moyens d’appui 7 comportent une règle 71 s’étendant selon la direction d’une géné ratrice du cylindre supérieur 5, et des moyens d’actionnement pour extraire la règle 71 du cylindre supérieur 5 pendant la phase de rabattement et la rétracter ensuite. Le rabatteur 6 est prévu pour rabattre le fond sur la deuxième paroi 22. Le rabatteur 6 est réalisé par un cylindre de rabattement 6 configuré pour serrer le sac 2 contre le cylindre inférieur 4 en étant rotatif dans le sens inverse du cylindre inférieur 4. The machine further comprises support means 7 for pressing on the second wall 22 after the upper clamps 51 have been released. The support means 7 comprise a rule 71 extending in the direction of a generator of the upper cylinder 5, and actuating means for extracting the rule 71 from the upper cylinder 5 during the folding phase and then retracting it. The reel 6 is designed to fold the bottom onto the second wall 22. The reel 6 is produced by a folding cylinder 6 configured to clamp the bag 2 against the lower cylinder 4 by being rotated in the opposite direction to the lower cylinder 4.
La machine met en oeuvre un procédé de formation d’un fond spécial sur les sacs 2 plats. The machine implements a process for forming a special bottom on the 2-flat bags.
Après que l’une des extrémités du sac 2 ait été fermée dans la station de formation de fond 1 par un rabat 25 issu de l’une des parois 21 et collé sur l’autre paroi 22, d’une manière connue en soi, le sac 2 est transporté dans une direction de transport par les moyens de réception 3, les bords longitudinaux 53 du sac 2 étant parallèles à la direction de transport Fl, vers le col entre les cylindres supérieur et inférieur 4, 5, lesquels sont contrarotatifs. L’extrémité fermée 20 du sac 2 dépasse le col et les moyens d’aspiration tendent à écarter la première 21 de la deuxième paroi 22. De plus, un canal est créé à l’intérieur du sac le long de chaque bord pour mettre en communication le fond avec l’ouverture du sac. Les pinces inférieures 41 et supérieures 51 sont actionnées pour saisir respectivement la première et la deuxième paroi 21, 22 à une dis tance prédéterminée de l’extrémité fermée 20 du sac 2. Ainsi les pinces 41, 51 s’introduisent dans l’espace délimité par les soufflets 24. Elles maintiennent la première paroi 21, respectivement la deuxième 22, sur le cylindre inférieur 4, respectivement supérieur 5.
Lors de la poursuite de la rotation des cylindres inférieur et supérieur 4, 5, les parois sont écartées à l’aide des pinces 41, 51 pour former une côte 27 sur les soufflets 24 s’étendant d’une paroi à l’autre 21, 22, comme montré sur la figure 3. La cavité ainsi créée se remplit d’air depuis l’extrémité ouverte en passant par les canaux d’alimentation en air. Les pinces supérieures 51 sont alors commandées pour lâcher la deuxième paroi 22. La règle 71 des moyens d’appui 7 est déployée pour appuyer sur la deuxième paroi 22 après le relâchement des pinces supérieures 51, comme le montre la figure 4. After one end of the bag 2 has been closed in the bottom forming station 1 by a flap 25 from one of the walls 21 and glued to the other wall 22, in a manner known per se, the bag 2 is transported in a direction of transport by the receiving means 3, the longitudinal edges 53 of the bag 2 being parallel to the direction of transport F1, towards the neck between the upper and lower cylinders 4, 5, which are counter-rotating. The closed end 20 of the bag 2 projects beyond the neck and the suction means tend to separate the first 21 from the second wall 22. In addition, a channel is created inside the bag along each edge to put in place communication the bottom with the opening of the bag. The lower 41 and upper 51 clamps are actuated to grip respectively the first and the second wall 21, 22 at a predetermined distance from the closed end 20 of the bag 2. Thus the clamps 41, 51 are introduced into the delimited space by the bellows 24. They hold the first wall 21, respectively the second 22, on the lower cylinder 4, respectively upper 5. During the continuation of the rotation of the lower and upper cylinders 4, 5, the walls are separated using the clamps 41, 51 to form a rib 27 on the bellows 24 extending from one wall to the other 21 , 22, as shown in Figure 3. The cavity thus created is filled with air from the open end through the air supply channels. The upper clamps 51 are then controlled to release the second wall 22. The rule 71 of the support means 7 is deployed to press on the second wall 22 after the release of the upper clamps 51, as shown in FIG. 4.
Le sac 2 poursuit sa trajectoire vers le cylindre de rabattement 6 pour ra- battre l’extrémité fermée 20 du sac 2 sur la deuxième paroi 22 en formant un premier pli 281 sortant sur la première paroi 21 entre les pinces inférieures 41, un deuxième pli 282 sortant sur la deuxième paroi 22 entre les extrémités des côtes 27, et un troisième pli 283 rentrant sur la deuxième paroi 22 symétrique ment à l’extrémité du sac 2 par rapport au deuxième pli 282, réalisant ainsi un fond 29 délimité entre le premier et le deuxième pli 281, 282. La distance entre l’extrémité fermée 20 et le premier pli 281, respectivement le deuxième pli 282 est sensiblement égale à la profondeur des soufflets 24. The bag 2 continues its path towards the folding cylinder 6 to fold the closed end 20 of the bag 2 onto the second wall 22 by forming a first fold 281 exiting on the first wall 21 between the lower clamps 41, a second fold 282 exiting on the second wall 22 between the ends of the ribs 27, and a third fold 283 returning to the second wall 22 symmetrically at the end of the bag 2 relative to the second fold 282, thus producing a bottom 29 delimited between the first and the second fold 281, 282. The distance between the closed end 20 and the first fold 281, respectively the second fold 282 is substantially equal to the depth of the bellows 24.
Lors de l’utilisation du sac 2, on peut l’ouvrir par l’extrémité ouverte en écartant la première et la deuxième paroi 21, 22, pour obtenir une forme comme sur la figure 6. Selon la nature du matériau du sac 2, celui-ci peut tenir debout sur le fond 29 créé selon le procédé. Le matériau peut être du papier, du film plastique ou un tissé en matière thermoplastique. When using the bag 2, it can be opened by the open end, spreading the first and second walls 21, 22, to obtain a shape as in FIG. 6. Depending on the nature of the material of the bag 2, it can stand upright on the bottom 29 created by the method. The material may be paper, plastic film or a woven material of thermoplastic material.
Dans une variante non représentée, on forme initialement les sacs fermés par le rabat 25, on les empile, puis on les dépile pour réaliser le fond 29. Des moyens de dépilage remplacent la station de formation de fond 1 et alimente les moyens de réception 3 avec les sacs un par un. In a variant not shown, the bags closed by the flap 25 are initially formed, they are stacked, then they are unstacked to make the bottom 29. Unstacking means replace the bottom forming station 1 and feeds the receiving means 3 with the bags one by one.
L’action des moyens d’appui 7 n’est pas indispensable, selon le compor tement du matériau formant les sacs. Le troisième pli 283 peut se former naturellement par l’action de rabattement.
Selon un deuxième mode de réalisation de l’invention, représenté sur la figure 7, la machine se distingue de celle du premier mode de réalisation en ce qu’elle comporte une station de refoulage 9 pour marquer les parois du sac et faciliter la mise en forme de celui-ci. La station de refoulage 9 est placée en amont des moyens d’aspiration 8 et comporte un cylindre de refoulage 91 et un contre-cylindre 91. Les deux cylindres 91, 92 sont montés rotatifs parallèlement l’un à l’autre et sont contrarotatifs. Le cylindre de refoulage 91 comporte deux lames 911, 912 s’étendant le long de deux génératrices et faisant saillie de la surface du cylindre 91. Le contre-cylindre 92 comporte une surface souple, réalisée par exemple par un revêtement en caoutchouc, au moins en regard des lames 911, 912. The action of the support means 7 is not essential, depending on the behavior of the material forming the bags. The third fold 283 can form naturally by the folding action. According to a second embodiment of the invention, shown in Figure 7, the machine differs from that of the first embodiment in that it comprises a delivery station 9 to mark the walls of the bag and facilitate the setting form of it. The discharge station 9 is placed upstream of the suction means 8 and comprises a discharge cylinder 91 and a counter-cylinder 91. The two cylinders 91, 92 are rotatably mounted parallel to one another and are counter-rotating. The discharge cylinder 91 has two blades 911, 912 extending along two generators and projecting from the surface of the cylinder 91. The counter-cylinder 92 has a flexible surface, produced for example by a rubber coating, at least opposite blades 911, 912.
En fonctionnement, la vitesse périphérique des cylindres 91, 92 est celle de défilement des sacs. Les lames 911, 912 viennent successivement pincer le sac 2 contre le contre-cylindre 92 et ainsi réaliser deux marquages sur chaque sac. De préférence, le premier marquage correspond au premier pli 281 et au deuxième pli 282, tandis que le deuxième marquage anticipe le troisième pli 283, comme montré sur la figure 8. La distance préférentielle entre le premier marquage et le bord de l’extrémité fermée est égale à la profondeur des soufflets. La distance préférentielle entre le deuxième marquage et le bord de l’extrémité fermée est égale à deux fois la profondeur des soufflets. Le reste du fonctionnement est similaire à celui qui a été décrit précédemment.
In operation, the peripheral speed of the cylinders 91, 92 is that of movement of the bags. The blades 911, 912 successively pinch the bag 2 against the counter-cylinder 92 and thus carry out two markings on each bag. Preferably, the first marking corresponds to the first fold 281 and to the second fold 282, while the second marking anticipates the third fold 283, as shown in FIG. 8. The preferential distance between the first marking and the edge of the closed end is equal to the depth of the bellows. The preferred distance between the second marking and the edge of the closed end is twice the depth of the bellows. The rest of the operation is similar to that which has been described previously.
Claims
1. Procédé de formation de sac (2) flexible, le sac (2) comportant une pre mière paroi (21) et une deuxième paroi (22) superposée à la première paroi (21), les parois (21, 22) étant reliées entre elles le long de bords longitudinaux (53) par deux soufflets (24), selon lequel, successivement : on ferme le sac (2) pour former une extrémité fermée (20) du sac (2) à l’opposé d’une extrémité ouverte, on saisit à une distance prédéterminée de l’extrémité fermée (20) du sac (2) la première paroi (21) par des pinces inférieures (41) montées sur un support inférieur (4) et la deuxième paroi (22) par des pinces supérieures (51) montées sur un support supérieur (5) et on écarte les parois à l’aide des pinces (41, 51), on lâche la deuxième paroi (22) par les pinces supérieures (51) et on rabat (25) avec un rabatteur (6) l’extrémité fermée (20) sur la deuxième paroi (22) en formant un premier pli (281) sortant sur la première paroi (21) entre les pinces inférieures (41), un deuxième pli (282) sortant sur la deuxième paroi (22) entre les extrémités des côtes (27), et un troisième pli (283) rentrant sur la deuxième paroi (22) symétriquement à l’extrémité du sac (2) par rapport au deuxième pli (282), réalisant ainsi un fond (29) délimité entre le premier et le deuxième pli ( 281, 282), le procédé étant caractérisé en ce que lors de l’écartement des pinces (41, 51), on forme une côte (27) sur les soufflets (24) s’étendant d’une paroi à l’autre (21, 22). 1. Method for forming a flexible bag (2), the bag (2) comprising a first wall (21) and a second wall (22) superimposed on the first wall (21), the walls (21, 22) being connected between them along longitudinal edges (53) by two bellows (24), according to which, successively: the bag (2) is closed to form a closed end (20) of the bag (2) opposite one end open, the first wall (21) is gripped at a predetermined distance from the closed end (20) of the bag (2) by lower clamps (41) mounted on a lower support (4) and the second wall (22) by upper clamps (51) mounted on an upper support (5) and the walls are spread apart using the clamps (41, 51), the second wall (22) is released by the upper clamps (51) and the flap ( 25) with a reel (6) the closed end (20) on the second wall (22) by forming a first fold (281) exiting on the first wall (21) between the lower clamps (41), a second fold ( 282) sorta nt on the second wall (22) between the ends of the ribs (27), and a third fold (283) returning to the second wall (22) symmetrically at the end of the bag (2) relative to the second fold (282) , thus producing a bottom (29) delimited between the first and the second fold (281, 282), the method being characterized in that when the spacers of the clamps (41, 51) are formed, a rib (27) is formed on the bellows (24) extending from one wall to the other (21, 22).
2. Procédé selon la revendication 1, selon lequel on appuie avec des moyens d’appui (7) sur la deuxième paroi (22) après le relâchement des pinces supérieures (51). 2. Method according to claim 1, according to which it is supported with support means (7) on the second wall (22) after the release of the upper clamps (51).
3. Procédé selon l’une des revendications précédentes, selon lequel on main tient un écartement entre la deuxième paroi (22) et la première paroi (21) sur au moins une partie de la largeur du sac (2) et sur toute sa longueur
afin de créer un canal d’alimentation en air depuis l’extrémité ouverte jusqu’à l’extrémité fermée (20). 3. Method according to one of the preceding claims, according to which a hand is held between the second wall (22) and the first wall (21) over at least part of the width of the bag (2) and over its entire length. to create an air supply channel from the open end to the closed end (20).
4. Procédé selon l’une des revendications précédentes selon lequel on forme initialement les sacs fermés par le rabat (25), on les empile, puis on les dépile pour réaliser le fond (29). 4. Method according to one of the preceding claims according to which the bags closed by the flap (25) are initially formed, they are stacked, then they are unstacked to form the bottom (29).
5. Procédé selon l’une des revendications 1 à 3, selon lequel la formation du fond (29) est réalisée en ligne avec la formation du sac (2). 5. Method according to one of claims 1 to 3, according to which the formation of the bottom (29) is carried out in line with the formation of the bag (2).
6. Procédé selon l’une des revendications précédentes selon lequel la distance prédéterminée entre l’extrémité fermée (20) et le premier pli (281), res- pectivement le deuxième pli (282) est sensiblement égale à la profondeur des soufflets (24). 6. Method according to one of the preceding claims, in which the predetermined distance between the closed end (20) and the first ply (281), respectively the second ply (282) is substantially equal to the depth of the bellows (24 ).
7. Machine de fabrication de sacs flexibles, le sac (2) comportant une pre mière paroi (21) et une deuxième paroi (22) superposée à la première paroi (21), les parois (21, 22) étant reliées entre elles le long de bords longitudinaux (53) par deux soufflets (24), une extrémité (20) du sac (2) étant fermée , la machine étant caractérisée en ce qu’elle comporte des moyens de réception (3) pour recevoir en série des sacs (2) se déplaçant dans une direction principale (Fl) parallèle aux bords longitudinaux (53), l’extrémité fermée (20) en avant, un support inférieur (4) pour supporter deux pinces inférieures (41), les pinces inférieures (41) étant agencées pour saisir la première paroi (21) à une distance prédéterminée de l’extré mité fermée (20) du sac (2), un support supérieur (5) pour supporter des pinces supérieures (51), les pinces supérieures (51) étant agencées pour saisir la deuxième paroi (22) à une distance prédéterminée de l’extrémité fermée (20) du sac (2), le support supérieur (5) et le support inférieur 7. Machine for manufacturing flexible bags, the bag (2) comprising a first wall (21) and a second wall (22) superimposed on the first wall (21), the walls (21, 22) being interconnected the along longitudinal edges (53) by two bellows (24), one end (20) of the bag (2) being closed, the machine being characterized in that it comprises receiving means (3) for receiving bags in series (2) moving in a main direction (F1) parallel to the longitudinal edges (53), the closed end (20) forward, a lower support (4) for supporting two lower clamps (41), the lower clamps (41 ) being arranged to grip the first wall (21) at a predetermined distance from the closed end (20) of the bag (2), an upper support (5) for supporting upper clamps (51), the upper clamps (51 ) being arranged to grip the second wall (22) at a predetermined distance from the closed end (20) of the bag (2), the upper support (5) and the lower support
(4) étant agencés pour écarter les pinces inférieures (41) des pinces su périeures (51) pour former une côte (27) sur les soufflets (24) s’étendant d’une paroi à l’autre (21, 22), un rabatteur (6) pour rabattre le fond (29) sur la deuxième paroi (22) en formant un premier pli (281) sortant sur la première paroi (21) entre les pinces inférieures (41), un deuxième pli (282) sortant sur la deuxième paroi (22) entre les extrémités des côtes (27), et
un troisième pli (283) rentrant sur la deuxième paroi (22) symétriquement à l’extrémité du sac (2) par rapport au deuxième pli (282). (4) being arranged to separate the lower clamps (41) from the upper clamps (51) to form a rib (27) on the bellows (24) extending from one wall to the other (21, 22), a reel (6) for folding the bottom (29) onto the second wall (22) by forming a first fold (281) coming out on the first wall (21) between the lower clamps (41), a second fold (282) coming out on the second wall (22) between the ends of the ribs (27), and a third fold (283) returning to the second wall (22) symmetrically at the end of the bag (2) relative to the second fold (282).
8. Machine selon la revendication 7, dans laquelle les supports inférieur et supérieur sont des cylindres contrarotatifs respectivement inférieur et su périeur (4, 5). 8. Machine according to claim 7, in which the lower and upper supports are respectively lower and upper counter-rotating cylinders (4, 5).
9. Machine selon la revendication 8, caractérisée en ce qu’elle comporte des moyens d’appui (7) pour appuyer sur la deuxième paroi (22) après le relâchement des pinces supérieures (51) et qui comportent une règle (71) s’étendant selon la direction d’une génératrice du cylindre supérieur (5), et des moyens d’actionnement pour extraire la règle (71) du cylindre supérieur (5) pendant la phase de rabattement et la rétracter ensuite. 9. Machine according to claim 8, characterized in that it comprises support means (7) for pressing on the second wall (22) after the release of the upper clamps (51) and which include a rule (71) s extending in the direction of a generator of the upper cylinder (5), and actuating means for extracting the rule (71) from the upper cylinder (5) during the folding phase and then retracting it.
10. Machine selon l’une des revendications 7 à 9, dans laquelle le rabatteur est réalisé par un cylindre de rabattement (6) configuré pour serrer le sac (2) contre le support inférieur (4). 10. Machine according to one of claims 7 to 9, wherein the reel is made by a folding cylinder (6) configured to clamp the bag (2) against the lower support (4).
11. Machine selon l’une des revendications 7 à 10, dans laquelle le support inférieur (4) et/ou le support supérieur (5) comporte des moyens d’as piration pour aspirer respectivement la première et/ou la deuxième paroi (21, 22) de manière à les séparer avant la saisie par les pinces (41, 51). 11. Machine according to one of claims 7 to 10, in which the lower support (4) and / or the upper support (5) comprises suction means for sucking the first and / or the second wall respectively (21 , 22) so as to separate them before gripping by the clamps (41, 51).
12. Machine selon la revendication 11, dans laquelle les moyens d’aspiration s’étendent en amont du support supérieur sur une longueur suffisante pour créer au moins un canal d’alimentation en air depuis l’extrémité ouverte du sac jusqu’à l’extrémité fermée (20). 12. Machine according to claim 11, wherein the suction means extend upstream of the upper support over a length sufficient to create at least one air supply channel from the open end of the bag to the closed end (20).
13. Machine selon la revendication 12, dans laquelle les moyens d’aspiration comportent une bande perméable à l’air montée en boucle et contre la quelle la deuxième paroi du sac est aspirée, la bande étant entraînée pour défiler à la même vitesse que le sac. 13. Machine according to claim 12, wherein the suction means comprise a breathable band mounted in a loop and against which the second wall of the bag is sucked, the band being driven to scroll at the same speed as the bag.
14. Machine selon l’une des revendications 7 à 13, caractérisé en ce qu’elle comporte une station de refoulage (9) pour marquer les parois du sac selon un premier marquage à une distance prédéterminée de l’extrémité fermée (20) et selon un deuxième marquage à la même distance prédéterminée du premier marquage.
14. Machine according to one of claims 7 to 13, characterized in that it comprises a delivery station (9) for marking the walls of the bag according to a first marking at a predetermined distance from the closed end (20) and according to a second marking at the same predetermined distance from the first marking.
15. Machine selon la revendication 14, dans laquelle la station de refoulage (9) comporte un cylindre de refoulage (91) et un contre-cylindre (91) montés contrarotatifs parallèlement l’un à l’autre, le cylindre de refoulage (91) comporte deux lames (911, 912) s’étendant le long de deux génératrices et faisant saillie de la surface du cylindre (91), le contre-cylindre (92) comportant une surface souple.
15. Machine according to claim 14, in which the delivery station (9) comprises a delivery cylinder (91) and a counter-cylinder (91) mounted counter-rotating parallel to each other, the delivery cylinder (91 ) comprises two blades (911, 912) extending along two generators and projecting from the surface of the cylinder (91), the counter-cylinder (92) comprising a flexible surface.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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FR1872808A FR3089860B1 (en) | 2018-12-12 | 2018-12-12 | Special Bottom Flexible Bag Forming Method and Machine |
PCT/EP2019/084737 WO2020120616A1 (en) | 2018-12-12 | 2019-12-11 | Method and machine for forming flexible bags with special bottom |
Publications (1)
Publication Number | Publication Date |
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EP3894204A1 true EP3894204A1 (en) | 2021-10-20 |
Family
ID=66049342
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19817711.5A Pending EP3894204A1 (en) | 2018-12-12 | 2019-12-11 | Method and machine for forming flexible bags with special bottom |
Country Status (4)
Country | Link |
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US (1) | US11833775B2 (en) |
EP (1) | EP3894204A1 (en) |
FR (1) | FR3089860B1 (en) |
WO (1) | WO2020120616A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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FR3122847B1 (en) | 2021-05-12 | 2023-05-12 | Holweg Group | Process and machine for manufacturing a flexible bag of the envelope type, in particular with reinforcement |
WO2022238301A1 (en) | 2021-05-12 | 2022-11-17 | Holweg Group | Flexible bag having a convertible bottom, method and machine for manufacturing same |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR786579A (en) | 1934-06-26 | 1935-09-05 | Holweg Const Mec | Method and devices for the production of flat bags |
US2324358A (en) * | 1941-01-21 | 1943-07-13 | Potdevin Machine Co | Bag making machine |
US2847914A (en) * | 1956-03-09 | 1958-08-19 | Equitable Paper Bag Co | Bag bottoming machine |
FR1270400A (en) | 1960-10-13 | 1961-08-25 | Holweg Const Mec | Machine for the continuous production of bags and flat sachets |
US3606822A (en) * | 1970-01-12 | 1971-09-21 | Nat Distillers Chem Corp | Method and apparatus for producing a flat-bottom plastic bag |
DE2255768C3 (en) * | 1972-11-14 | 1978-09-14 | Windmoeller & Hoelscher, 4540 Lengerich | Method and device for producing block-bottom bags from heat-sealable material |
DE2256913A1 (en) * | 1972-11-20 | 1974-05-22 | Windmoeller & Hoelscher | METHOD OF MANUFACTURING A BLOCK BOTTOM BAG |
US3967544A (en) * | 1973-05-01 | 1976-07-06 | National Petro Chemicals Corporation | Grocery sack process and machine |
FR2351021A1 (en) * | 1976-05-10 | 1977-12-09 | Holweg Const Mec | PROCESS AND DEVICE FOR MAKING A SQUARE BOTTOM BAG |
US5609556A (en) * | 1994-05-27 | 1997-03-11 | Fischer & Krecke Gmbh & Co. | Method and apparatus for manufacturing bags with strap-shaped carrying handles |
FR2992254B1 (en) | 2012-06-20 | 2014-08-15 | Holweg Sas | MACHINE FOR MANUFACTURING BAGS WITH FLAT BOTTOM. |
FR3030352B1 (en) | 2014-12-19 | 2018-09-07 | Holweg Group | METHOD AND MACHINE FOR MANUFACTURING BAGS |
US20180155084A1 (en) * | 2016-10-07 | 2018-06-07 | Gateway Packaging Company | Flat Patch Bottom Self Opening Style Bag and Method of Manufacture |
-
2018
- 2018-12-12 FR FR1872808A patent/FR3089860B1/en active Active
-
2019
- 2019-12-11 WO PCT/EP2019/084737 patent/WO2020120616A1/en unknown
- 2019-12-11 US US17/413,220 patent/US11833775B2/en active Active
- 2019-12-11 EP EP19817711.5A patent/EP3894204A1/en active Pending
Also Published As
Publication number | Publication date |
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US11833775B2 (en) | 2023-12-05 |
FR3089860A1 (en) | 2020-06-19 |
FR3089860B1 (en) | 2020-12-04 |
US20220055333A1 (en) | 2022-02-24 |
WO2020120616A1 (en) | 2020-06-18 |
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