| JP3774545 | METHOD AND APPARATUS FOR MANUFACTURING BAG WITH PORTABLE HANDLE |
| WO/1998/048202 | SEAL PRESSURE APPLIANCE FOR SEAL |
| WO/1993/010968 | APPARATUS FOR FORMING AND APPLYING HANDLES TO BAGS |
GIACOMETTI, Stefano (J.W.T. snc, Via Prati 5, Vigonza, I-35010, IT)
| CLAIMS 1. Paper bag (S) comprising a folded and glued sheet (F), with at least two handles (M) arranged in proximity to two opposite edges (Fl) of said sheet (F) forming the upper edges (Fl) of said bag (S), said sheet (F) being folded at least along one line transversal to the longitudinal axis that joins said handles (M), said line forming the continuous and jointless bottom (Fl), characterized in that the glued side edges (CI, C2) of said bag (S) are cut along a single straight line and glued by simply placing them over each other, without overlapping or folding them, in order to obtain the two vertical sides of the bag (S). 2. Paper bag (S) according to claim 1, characterized in that said bottom (F2) is pre-cut and folded like a bellows towards the inside of the bag (S). 3. Paper bag (S) according to claim 2, characterized in that on said bottom (F2) a substantially triangular recess (Z) is created, by means of an oblique cut with respect to the x-axis, at the level of the transversal cut (Y), said recess making it possible to eliminate the excess paper resulting from the bag forming process near the bottom for exclusively aesthetical purposes. 4. Paper bag (S) according to claims 1, 2, 3, characterized in that each one of said handles (M) is applied to the surface of said sheet (F) facing the inside of the bag (S). 5. Paper bag (S) according to claim 4, characterized in that each one of said handles (M) comprises at least one reinforcing strip or band, made of paper or cardboard, applied to said sheet (F) in proximity to the corresponding edge (Fl). 6. Paper, bag (S) according to claims 5, characterized in that in proximity to said upper edges (Fl) it comprises holes suited to form the grip of 1iie handles (M) owing to the fact that they are obtained by partial or complete cutting or folding or removal of at least one portion of said sheet (F). |
DESCRIPTION
The present patent concerns the sector of paper bags commonly called shoppers, and in particular it concerns a new type of paper shopper or bag with jointless and continuous bottom whose side edges are glued without folding them.
Paper bags may or not be provided with handles, a detail that makes the manufacture of said bags more or less complicated.
At present, the diffusion of paper bags to be used as shopping bags is limited, mainly due to their high production costs.
Apart from the intrinsic cost of the raw material, production speed strongly affects the price of paper bags. In order to be able to understand what may hinder any increase in the speed of the production process of paper bags of known type, it is necessary to analyze the present production process.
The production of all the paper bags currently available includes a step for opening, folding and glueing the bottom, which represents a critical moment and does not allow certain production speeds to be exceeded. The process for making the bottom of the bags of known type takes place after the sheet has been folded longitudinally and after the sheet has been cut to separate the individual bags.
Patent no. US 2985355 is known, which concerns a paper bag folded in two with continuous bottom, where the side edges are closed via a folding and glueing process, which requires a further processing step with the production line at rest. The successive step must practically be carried out manually or with complex equipment that would considerably slow down a hypothetical industrial cycle, so much so that it would not be convenient to manufacture paper bags with this system (as confirmed by the fact that this type of product was abandoned long ago).
Therefore, it is necessary to devise a new paper bag that allows the main cutting operation to be performed only at the end of the manufacture of the entire paper bag.
Consequently, a new type of paper shopper or bag has been designed and manufactured, with jointless and continuous bottom, whose side edges are glued without folding them, and wherein said paper shopper or bag is arranged on the production line with its main longitudinal axis in a position substantially orthogonal to the advance direction.
The main object of the new paper shopper or bag is to have lower production costs than the paper bags of known type, thanlcs to the fact that it can be manufactured on a continuous production line, thus maximizing production speed and reducing the relative costs.
The new paper shopper or bag comprises at least one folded sheet, where the bottom is continuous and jointless, being defined by the fold/s of the sheet along at least one intermediate transversal line.
The side edges of the sheet, instead, are glued by spreading glue on the edges facing the same side of the sheets, so that they can be glued with no need to be folded.
Therefore, differently from the paper bags of known type, whose bottom or edges are obtained by folding and glueing the edges of the sheet, in the new paper bag the sides are simply superimposed and glued but the bottom is continuous and jointless. The new bag also comprises a pair of handles positioned on the edges of the folded sheet and defining the open top of the bag.
Said handles can be of the so-called "bean" type, that is, they can be obtained by directly cutting two elongated holes in corresponding positions in the two opposite upper edges of the folded sheet, or of the so-called "cord" type, that is, of the type comprising each a cord or strip, in paper or fabric, applied to the upper edges of the bag to form a grip. The characteristics of the new bag and of the system for the manufacture thereof will be highlighted in greater detail in the following description with reference to the drawings that are attached as non-limiting examples.
Figure 1 shows a front-to-side view of the paper bag comprising a paper sheet (F) folded on the bottom, where two upper edges (Fl) are obtained. The lower external edge (X3) is folded like a bellows and the corner edge (Z) is cut and glued.
It is also possible to observe the two handles (M) arranged in proximity to the upper edge (Fl). The side edges (CI, C2) are glued along the entire side of the bag (S).
The successive figures show the bag during the manufacturing process. The arrow (w) indicates the direction of advance of the sheet (F).
Figures 2 shows the paper sheet (F) unrolled but still attached to the roll, before being folded at the centre to obtain the jointless bottom; it is also possible to observe the handles (M) already applied i proximity to the upper edges (Fl), and the areas (C) to which glue is applied. After the folding step, said areas (C) wet with glue will adhere to the corresponding areas (C) with respect to the central axis (X) of the sheet (F) that hasn't been separated from the roll yet. Figures 2 and 3 show the bag (S) after folding along the central axis (X), and the corresponding bellows (XI, X2), wherein said fold, which can be simple or triple to form a bellows, makes up the lower edge or bottom (F2)..The areas (C) wet with glue have adhered to each other forming a series of pockets (T) open on the upper side (Fl). In order to obtain the individual bags (S), the paper sheet (F) is cut on the Y-axis, at the level of the glued parts (C), in such a way as to obtain, for each bag, two superimposed sides that aren't folded and are completely glued (CI, C2), a continuous bottom (F2) and two upper edges (Fl) that are open (T) to allow the products to be put in the bag.
The lower fold is carried out in three lines (XI, X, X3), in order to obtain a lower bellows. Even the side edges will be folded according to parallel lines (L), in such a way as to obtain a bag with a bellows.
Figure 3 shows once again the bags during manufacture, and it is possible to observe that on the lower edge, at the level of the glued areas and aligned with the cutting line (Y), a substantially triangular recess (Z), at 90°, is carried out with an oblique cut with respect to axes x and y, said recess eliminating part of the angles of the bottom for exclusively aesthetical purposes.
Finally, it can be observed that the last bag (S) on the right has already been cut at the level of its left edge, is provided with rounded lower edges (Z) and has been detached from the paper sheet.
Figure 4 shows the closed bag ready to be stacked and packaged.
At this point a paper bag (S) has been obtained from the continuous roll, a bag that is manufactured and completely finished on a continuous production line, where cutting and separation from the roll are the last operations carried out, obviously before stacking and packaging.
All the stages and operations necessary for completing the bag (S), except for the stacking stage of the finished bags (S), are performed working on continuous forms, that is, on the continuous sheet (F), which is subjected neither to transversal cutting operations nor to stoppages during its advance (X) until the final transversal cut is carried out.
Therefore, with reference to the above description and the attached drawings, the following claims are expressed.