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(11) | EP 2 508 440 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Bag with laminated mouth part and its production method Tasche mit laminiertem Mundteil und Herstellungsverfahren dafür Sac avec embouchure laminée et son procédé de production |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
Technical Field
[0001] The present invention is related to increase the endurance of the mouth part of net, knitted or woven bags (cases) by laminating (covering) the mouth part of such bags or cases and is related to innovations that are made in order to ensure that the weft and warp threads (strips) located in the said mouth part are not split away from each other.
Prior Art
[0002] The mouth parts of the non laminated bags (cases) in the prior art are subjected to high force from the handle parts of the bags or cases that are used in order to carry the load inside such cases and are easily ripped and/or fall apart from this pressure or force. For this reason, the mouth parts of especially woven bags should be strengthened.
[0003] This said strengthening has been provided by supplying taught stitching named overlocking on the mouth parts of the bags known in the prior art. However, this process, is a process that is carried out after the manufacturing of the said bags are completed so an extra amount of workmanship is needed and thus the costs also increase due to this extra workmanship.
[0004] In the patent document numbered US3979049A in which a reinforced bag known the prior art is being explained, a bag which has a bottom part which closes by the overlapping of the bottom sides of the bag which is then reinforced by placing a placard to the base section formed is described. The additional material used as reinforcement in the said bag or case also increases the costs of the bag. Aside from this it is not possible to apply this above mentioned method to non laminated bags and especially to loosely woven bags (cases) such as string bags.
[0005] The patent document no US3970503 A discloses a bag made of net material with a mouth and a flap extending beyond said mouth. The flap comprises a piece of sheet material secured to one wall of the bag and a strip of heat-sealed plastic film secured to the inside wall of the bag by adhering it thereto by means of stripes of hot melt adhesive. In the said method a melt adhesive is used to secure the sheet material to inside of the bag.
[0006] The patent document no US4207983A discloses a net bag having strips of film secured to opposite walls thereof at its mouth, one strip constituting a wicketing flap, the other enabling automatic opening of the bag, a stack of such bags held together in the stack by a wicket having its legs extending through the wicketing flaps of the bags, and a method of making the bags. In the said method, after the cutting the fabric, a molten polyethylene resin, which is in the form of a filament, is applied outer surface of the produced bag.
[0007] Another patent document no WO99/15418A1 discloses a mesh bag comprising an open, mesh-like fabric. Said bag comprises heat-sealed side seams extending from one end to the other in order to secure two single knitted net fabrics.
Brief description of the invention
[0008] The present invention is related to a method for producing a net type, knitted or woven bag (case) with a laminated (coated) mouth.
[0009] While fast and continuous bag (case) production is ensured via the method of the prior art, low costing bags with reinforced mouth areas are being obtained with this said method. Thus problems such as the high costs of reinforced bags reinforced through taught stitching named overlocking in the prior art and their partial production rather than continuous production can be overcome by using this developed method.
The aim of the invention
[0010] The aim of the present invention is to develop a production method to produce a net type, knitted or woven bag (case) with a laminated (coated) mouth section.
[0011] Another aim of the present invention is to develop a production method to produce continually a net type, knitted or woven bag (case) which has a laminated (coated) mouth section.
[0012] Yet another purpose of the present invention is to develop a production method to produce a cost effective and high endurance net type, knitted or woven bag (case) which has a laminated (coated) mouth section
The description of the drawings
[0013] The exemplary embodiments of the bags (cases) produced in accordance with the said production method to produce net type, knitted or woven bag (case) which has a laminated (coated) mouth section in the prior art have been illustrated with the drawings attached and the said drawings illustrate the following:
Figure 1; is the illustration of a net type bag (case) known in the priorart.
Figure 2; shows a net type bag (case) with a laminated (coated) mouth section produced in accordance with the invention.
Figure 3; shows a woven bag (case) woven according to the prior art.
Figure 4; shows a woven bag (case) with a laminated (coated) mouth section produced in accordance with the developed method.
Figure 5; shows a semi finished state (tubular) of the woven bag with a laminated (coated) mouth section produced in accordance with the method of the invention.
[0014] The parts in the figures are individually enumerated and the corresponding terms of reference numbers are as follows:
| Bag (Prior art) | T' |
| Bag | T |
| Mouth | A |
| Bottom section/base | B |
| Overlocking | O |
| Semi finished bag (Tubular structure) | Y |
| Laminate (coating) | L |
Detailed Description of the Invention
[0015] The examplary illustrations of the net type, knitted or woven bags (T') in the known state of the art are shown in Figure 1 and Figure 3. In the prior art (T'), the mouth (A) part of the bag is strengthened by using the overlocking (O) method. The bags (T'), that have been reinforced with the said method, are strengthened with a second process following the process of being cut in suitable measurements and by producing a bag (T') by sealing at least one side of the said bag. For this reason, the production period and cost of the reinforced bags (T') reinforced by using the overlocking (O) method increase.
[0016] The net type, knitted or woven bags (T) (cases), produced according to the method of the present invention, can be seen in Figure 2 or Figure 4. The production method for the bags (cases) that have been improved comprises the steps according to claim 1.
[0017] A laminated (L) (coated) section is established according to the developed production method by using a coating material (preferably hot melt) at certain intervals to coat over the tubular structure (Y) used in the production of a bag (T). Following this process, the tubular structure (Y) is cut so that a mouth section (A) is left out of a laminated (L) (coated) bag (T) and a half open knitted/woven structure (not shown in the drawings) with the cut out laminated (L) section is obtained. The bottom or base part (B) of the obtained structure is sealed with a known method (preferably sealed by stitching) and thus a laminated bag (T) is obtained. After the laminate (L) becomes solid and turns into a block structure a high endurance laminate (coating) (L) is obtained for the bag (T).
[0018] With the production carried out according to the developed method, as the laminate (L) can be applied quickly to the tubular structure (Y), the steps of forming the tubular structure (Y), applying the laminate (L), and the confectionary processes (cutting of the structure (Y) and sealing of one side (B)) can be performed continuously in a production method. Thus the fast and economical production of the bag (T) is ensured.
[0019] The weaving threads (strips) forming the tubular structure (Y) and/or the laminate (L) according to the developed production method can comprise polyethylene, polypropylene, high density polyethylene and/or low density polyethylene.
[0020] While fast and continuous bag (case) production is provided via the developed method, low costing bags with reinforced mouth areas are being obtained with this said method. Thus difficulties such as the high costs of reinforced bags reinforced through taught stitching named overlocking in the known state of the art can be overcome by using this developed method.
- The threads forming the bag (T) are woven in order to establish a tubular structure (Y);
- The hot melt, glue and similar liquid and adhesive structured laminate (L) is applied in certain intervals to the tubular structure (Y) in vertical strips; being transversal in respect of the longitudinal axis of the said tubular structure (Y);
- The tubular structure (Y) is cut so as to form a mouth section (A) of the laminated (L) bag (T) all along the longitudinal edge of the laminate (L) established, creating on the one side of the cut said mouth section (A) of one bag and on the other side a bottom part (B) of the following bag;
- The pieces formed by cutting the tubular structure (Y), form the bag (T) by sealing at least one side of the tubular structure (Y) which stands transversal in respect of the longitudinal axis of the said tubular structure (Y).
- die Fäden oder das Garn, welche die Tasche (T) bilden, gewebt sind, um eine rohrförmige Struktur zu bilden (Y);
- ein heißer Klebstoff oder eine Heißschmelze oder eine ähnliche Flüssigkeit und ein adhäsives, strukturiertes Laminat (L) auf die rohrförmige Struktur (Y) in vertikalen Streifen angewendet werden, und zwar in bestimmten Intervallen oder Abständen, wobei die Streifen quer zur Längsachse der rohrförmigen Struktur (Y) verlaufen;
- die rohrförmige Struktur (Y) be- oder geschnitten wird, so dass sich ein Mundabschnitt (A) der laminierten (L) Tasche (T) entlang der Längskante des Laminats (L) bildet, wodurch sich auf der einen Seite des Schnitts der Mundabschnitt (A) einer Tasche und auf der anderen Seite ein unterer Abschnitt (B) der folgenden Tasche bildet;
- die Stücke, welche durch das Schneiden der rohrförmigen Struktur (Y) gebildet wurden, die Tasche (T) bilden, durch Verschmelzen oder Kleben zumindest der einen Seite der rohrförmigen Struktur (Y), welche sich in Querrichtung gegenüber der Längsachse der rohrförmigen Struktur (Y) erstreckt.
- les fils formant le sac (T) sont tissés afin d'établir une structure tubulaire (Y) ;
- le stratifié structuré adhésif et à thermocollant, colle, et liquide similaire (L) est appliqué dans certains intervalles à la structure tubulaire (Y) en bandes verticales ; transversales par rapport à l'axe longitudinal de ladite structure tubulaire (Y) ;
- la structure tubulaire (Y) est découpée de façon à former une section d'ouverture (A) du sac (T) stratifié (L) tout le long du bord longitudinal du stratifié (L) établi, créant du côté de la découpe ladite section d'ouverture (A) d'un sac et de l'autre côté une partie inférieure (B) du sac suivant ;
- les morceaux formés en découpant la structure tubulaire (Y), forment le sac (T) en scellant au moins un côté de la structure tubulaire (Y) qui se trouve transversale par rapport à l'axe longitudinal de ladite structure tubulaire (Y).
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description