FR2649728A1 - METHOD FOR MAKING BAGS BY WEAVING AND A NEW TYPE OF BAGS - Google Patents

Abstract

Process for making bags by weaving on a conventional loom equipped with a mechanism for controlling the warp threads according to the gauze weave. During weaving, a double fabric is produced consisting of two layers spaced apart from each other, said layers being linked to each other by respective interweaving of the warp and weft threads 1, 2 which make them up. along one of the edges, and also being linked, intermittently and at determined spaces, over their entire width also by respective intersection of the weft and warp threads of which they are composed.

Description

PROCESS FOR MAKING BAGS BY WEAVING AND

CALF TYPE OF BAGS.

  The present invention relates to an improvement made to the production of bags for packaging for storage, transport of various products including bulk products, such as food products (fruits, vegetables ..); it also concerns a new type of bags obtained by means of a

such a method.

  It relates more specifically to a new

  type of openwork bag obtained directly by weaving.

  To date, in the field of packaging, for certain products such as

  foodstuffs (potatoes, fruit ..), bags

  res, in the form of a closed pocket on three of its sides and open on the fourth, for

  enable the introduction of products and which is

closed after filling.

  In general, to perform the filling automatically, the bag is in the form of a continuous string that is unrolled in front of the filling assembly, so that the open area is arranged opposite of this zone, each bag being closed after filling and the bags being then separated from each other along their front binding zone

to be evacuated.

  Among all the solutions proposed so far to make such openwork bags, besides the techniques of! knitting on Rachel loom which lead to deformable articles, it has been proposed to make them in

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  a perforated fabric obtained with armor "no gauze"

  to ensure the perfect maintenance of the long-lasting

  longitudinal relative to the transverse wires. The fabric

  The resulting dish is then made in such a way as to

  close the sides. Besides this sewing operation, it is unfortunately not possible to obtain with this technique bags connected to each other

  in the form of rosaries for automatic filling

  tick. For the record, and in order to clearly define the invention, woven armor "no gauze" means the technique

  which, compared to a conventional warp and weft fabric

  nel, is not only to move the warp son relative to the weft son to achieve their connection, but also to move the warp son relative to each other, two by two, so that one of the son said "son of turn" passes alternately on either side of the other wire called "warp", the frame being trapped and being blocked between these two son, which allows to obtain a perforated fabric whose days are perfectly defined, the warp threads

  can not slide with respect to the weft threads.

  Such a technique of weaving type "gauze" has been known for a long time and essentially consists of adapting the looms so that the warp son can not only receive movements

  to form the crowd, but also

  transversal events to link them together in pairs.

  To do this, we use for the control of the son of

  chain of so-called "two-body" sets equipped with mail-

  the so-called "gauze" type, the best known being those

  marketed by GROB. In such a com-

  mand, each body consists of two smooth frames

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  who alternately order a "gauze" mesh in

which passes a warp.

  Now it has been found, and this is the subject of the present invention, that it was possible, by adapting this weaving technique to achieve

  "gauze" type fabrics to obtain, directly on a

  thanks to a simple, economical and fast process, bags in the form of closed pockets on three of their

  sides and open on the fourth, the said bags are

  feeling also at the fall of the craft, in the form of a continuous rosary allowing their possible

automatic filling.

  In general, the process according to the invention

  tion is to fabricate a fabric on a

  ventional equipped with a mechanism for controlling warp threads in a "gauze" armor and is characterized

  when weaving, a double fabric is made

  two webs spaced apart from one another, said webs being connected to each other by intercrossing

  respective warp and weft threads which

  along one of the selvedges and also being intermittently bound to specific spaces along their entire width, also by respective interweaving of the threads

  of frame and chain that compose them.

  In the rest of the description, for the sake of simplicity

  plication, the bonding of the two woven plies along

  one of the selvedges will be referred to as "Liaison".

  longitudinal "and that carried out at regular intervals

  in the sense of the width of the fabric, by the expression

cross-connection.

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  For the implementation of the method according to the invention, a conventional loom is used.

  being a dobby (a well-known mechanism

  both the control of ups and downs of frames), this dobby ensuring the control of four bodies no gauze

  mounted head to tail (two bodies above the chaff wires)

  the other two below), each body being

  staged two frames that alternately

  mesh "gauze" in which passes a warp.

  Thanks to such an adaptation of the loom, he

  is possible, if we consider an armor ratio (four

  to be son of chain) to realize either two gauze fabrics

  superimposed and spaced from each other and intermittently

  tence, to bind these two tissues in the transverse direction.

  The connection in the longitudinal direction along a line

  For its part, it is made by normal weaving by making the four threads of an armor ratio work in a conventional manner without forming gauze. The control of the bodies no gauze is carried out so that if we consider a chain armor ratio that is four son, that we form a top sheet to

  using two of these threads, one forming a thread of chai

  ne, the other the lap wire, and a lower lap with the other two, one forming the chain wire, the other the lap wire and that, in the connecting zones, the lap wire of the The upper web and the lap of the lower web intersect each other around the webs forming a monolayer fabric web. Proceeding according to the invention, thus obtaining at the output of the loom a continuous string consisting of successive pockets connected to each other transversely and along a selvedge,

  the other edge being open. It is pos-

  sible, from such a string of pockets, to realize

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  an automatic filling, the separation between the two consecutive pockets being made after closing by simple cutting in the middle of the transverse connection zone. The invention and the advantages it brings will however be better understood thanks to the embodiment given hereinafter by way of indication, but not limiting, and which is illustrated by the appended diagrams in which: FIG. 1 is a view schematic plan of a loom equipped for carrying out the method according to the invention; FIG. 2 is a side view showing in more detail the manner in which the eight bodies are mounted without gauze controlling the warp yarns to implement the method according to the invention and obtain the new type of bag also object of the invention. 'invention; - Figure 3 schematically illustrates the

  the continuous strip of bags

  according to the process according to the invention;

  FIG. 4 is a schematic view of a bag

  obtained by cutting such a continuous strip; - Figures Sa and 5b are schematic detail views, respectively in section in the weft direction (ST) and a top view of the product produced according to the invention; - Figures 6, 7 and 8 illustrate in more detail the

  the manner in which weaving is carried out and more particularly

  30: the realization of the upper layer (FIG. 6), the production of the lower layer (FIG. 7), and the connection of these two layers together (FIG. If reference is made to the attached diagrams for carrying out the process according to the invention, a

  loom which includes, as is schematically

  in Figure 1, a supply of warp yarns

  (1) (in the rest of the description, the warp threads

  will be designated by this reference (1) assigned an index a, b, c, d corresponding to an armor ratio) and a weft feed (2). The resulting fabric

is referred to in (3).

  To make such a fabric, the loom is equipped with a dobby (4) to ensure the control of lifts

  and lowering of cadres through tie rods (5).

  The frames (6) are, in accordance with the invention, in the name of

  of eight and are grouped respectively in the form of two upper bodies designated by the general reference (7) and two lower bodies designated by the general reference (8). In each body, the frames are grouped two by two, referenced frames (7a) and (7b) for the upper body (7) and (8b, 8c) for the lower body (8), and can alternately control a mesh " gauze "(9a, 9b, 9c, 9d) within which

  pass respectively the warp threads (la, lb, lc, ld).

  Thus, the warp thread (1a) passes into the mesh (9a) of the upper body controlled by the two frames (7a), the thread

  (Ib) passes into the mesh (9b) of the lower body

  sent by the two frames (8b), the thread (lc) in the mail-

  the (9c) of the second lower body and the wire (ld) in the mesh (9d) of the second upper body constituted by

the two frames (7d).

  Thanks to such an adaptation of the loom, it is possible, if we consider an armor ratio of

  four warp threads (la, lb, lc, ld) to perform, in accordance with

  in accordance with the method according to the invention, as the implementation is shown in detail in FIGS. 6, 7 and 8, on the one hand two gauze fabrics superimposed and spaced apart from each other, these fabrics being bonded together in the cross direction

with determined spaces.

  Figure 6 illustrates the manner in which the upper gauze fabric is made, Figure 7 the manner in which the lower fabric is formed and Figure 8 the manner in which

  are working the warp threads to make the

  intermediary link. By proceeding in this manner, tissues having the structure shown in cross-section (SC) in FIG. 5a are thus obtained and in order to

  above by Figure 5b. In Figure 5a, we can clearly see

  in the central part, the warp and weft threads form two superposed sheets spaced from one another respectively (11) and (12) and, on either side of these spaced plies, the threads of chain and weft are linked together to form zones of

  bond (13,14) constituted by a monolayer fabric.

  At the fall of a trade, we obtain a rosary

  in the form illustrated in Figure 3, is it

  ie consisting of a succession of pockets

  (20a, 20b, 20c, 20d) each having two spaced faces

  (11,12) a ventilated fabric gauze weave, these pockets being bonded together in the weft direction (ST) by continuous strips of fabric (13,14 ...). Moreover,

  along one of the selvedges, for example the straight edge

  the warp and weft threads work to

sea a monolayer fabric (15).

  By simply cutting between two successive links (13, 14 ..) (that is to say along the lines marked in phantom in FIG. 3) between two pockets, it is therefore possible to obtain an article having the configuration illustrated in FIG. Figure 4 and is in the form of a pocket open on one side and closed on its other three sides. The cutting can be carried out either before filling the bag or after filling, since the series of pockets formed can be used on

  automatic filling machines.

  The foregoing description clearly shows the advantages

  provided by the invention, in particular the fact that

  It is possible to easily obtain bags that can be

  made directly on the trade, no opera-

  subsequent finishing is not necessary.

  Of course, the invention is not limited to the embodiment described above, but it covers all variants made in the same spirit.

Claims (3)

  1 / Method for producing bags by weaving   on a conventional craft equipped with a com-   Means chain yarns according to the gauze armor, characterized in that during weaving, a double fabric is produced   consisting of two layers (11,12) spaced apart from each other   said webs being bonded to each other by respective interweaving of the warp and weft yarns (1,2) which compose them along one of the selvedges, and also being intermittently and spatially bound   determined throughout their entire width also by   respective crossing of the weft and warp threads compose them.   2 / A method according to claim 1, characterized in that one uses a conventional loom equipped with a dobby (4) ensuring the control of four bodies no gauze mounted head to tail (two bodies (7a, 7b) to above the warp yarns (1) and two bodies (8b, 8c) underneath said warp yarns), each warp yarn   (la, lb, lc, ld) passing in a mesh no gas (8a, -   8b, 8c, 8d ..) alternately controlled by two frames, the control of said warp threads being carried out so that if one considers an armor ratio (four warp threads), one carries out along the length of the fabric produces two superposed gauze fabrics spaced apart from each other, intermittently bonded to one another   single fabric in the transverse direction as well as, of course,   continuous in the longitudinal direction along an edge. 3 / Bag obtained for the implementation of the process   according to one of claims 1 to 2, characterized in that   that it presents itself, at the exit of the loom, under the   continuous rosary consisting of successive pockets   sives (20a, 20b, 20c ..) connected to each other transversely (13, 14 ...) as well as along a selvedge   (15), the other edge being open.