FR2554784A1 - PROCESS FOR FORMING THE BOTTOM OF A SOFT SYNTHETIC MATERIAL BAG FROM A SYNTHETIC CUSHION FILLED WITH LIQUID - Google Patents

Abstract

1. A process for forming the bottom of a bag made of flexible synthetic material from a cushion (1) made of synthetic material and filled with liquid, and for giving the bag stability, this process involving gripping each of the two lower corners (3, 4) of the cushion (1) by means of tongs (5), winding the said corner on itself about the pin supporting the tongs according to a specific number of revolutions, and then finally, after immobilization and removal of the tongs, welding the roll thus formed.

Description

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  The present invention relates to a process for forming the bottom of a bag of flexible synthetic material from a cushion

  made of synthetic material filled with liquid, and to give it stability.

  The invention also relates to the bags obtained according to this method and the device for its implementation. During the production of the flexible plastic containers, one of the problems posed is that of the stability of the bag, obtained by a specific conformation of the bottom of the bag to allow

laying on a flat surface.

  Multiple structures have been proposed and give satisfaction

  faction. For example, as in the French application 75.18358 in the name of the applicant, the bottom of the bag is shaped W by folding

  plastic film before filling.

  In the same way, the French patent 71.20879 proposes to conform the bottom by welding and cut corners forming ears after folding of the bottom. In these achievements, it is imperative that the

bag is empty.

  If the bottom W allows continuous work on machine with horizontal tracking, the structure of the patent 71.20879 can not be

obtained continuously.

  In addition, the two proposed achievements are necessary-

  made from empty bags at a given stage of their

tion.

  The same is true of the US patent. 3.829.007 which proposes a stable

  Lateral folding and welding. Here too, it is imperative

to work on an empty bag.

  The need is therefore felt for a method for continuously producing flat-bottomed sachets, with the same advantages as the W bottom, while allowing the intervention on a filled sachet, in the state

  intermediate cushion, more particularly for a process

  vertically, leading to a succession of cushions from

a continuous roll of film.

  According to the invention, this result is obtained with a method for forming the bottom of a bag of flexible synthetic material, from a plastic cushion filled with liquid, and to give it stability, which consists of pinch each of the two bottom corners of the cushion by a clamp, winding said corner on itself around the axis supporting the clamp, according to a determined number of rotations, and finally, after immobilization and withdrawal of the clamp, to

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solder the roll thus formed.

  The invention will be better understood from the description

  Hereinafter, a nonlimiting mode of implementation, with reference to the accompanying drawings in which: - Figure 1 is a schematic view of the taking of a corner of a cushion by a clamp, - Figure 2 illustrates the winding of the corner on itself, - Figure 3 illustrates the immobilization before removal of the clamp,

  - Figure 4 illustrates the final weld.

  We will first refer to Figure 1:

  A cushion (1) filled with liquid (2) is intended to be

  in a bag, from a continuous vertical or horizontal path,

  in this case preferably vertical.

  To impart shape and stability to the bag, it is contemplated to wind the two corners (3,4) of the cushion on themselves so as to form

stabilizing rollers.

  To do this, each of the wedges (3, 4) is grasped by means of a clamp (5) integral in rotation with an axis, shown, driven by a motor; the opening and closing commands of the clamp are the inside of the axis. A device allows the clearance of the axis and

the clamp after winding.

  When the corner, for example (3), is pinched, the rotation of the axis is controlled and the corner is wound in a winding (6) while driving

  the liquid towards the inside of the bag (figure 2).

  Then, we control the stop of the rotation and we block the roller

  (6) in position, applying a slight pressure by a jaw (7,8).

  Then remove the axis, and therefore the clamp (Figure 3).

  Finally, a heat of welding is applied to the roll (6).

  the jaw (7,8) can be, for example, a welding gun (fig.4).

  A bag bottom delimited by two rolls is thus produced.

  opposites that confer the desired form and stability.

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Claims (2)

  Process for forming the bottom of a flexible plastic bag from a liquid filled synthetic cushion and for providing stability thereto, characterized by gripping each of the two lower corners (3,4) of the cushion (1) by a clamp (5) to wind said wedge on itself around the axis supporting the clamp, according to a fixed number of rotations, then finally, after immobilization   and removing the clamp, soldering the roll thus formed.   2. Device for implementing the method according to the claim   1, characterized in that it comprises essentially a clamp (5) integral with an axis driven by a motor and movable in rotation with said axis, said clamp being provided with opening and closing controls interior to the axis , the axle can be released laterally after winding the wedge (3,4)