FR2843910A1 - PROCESS FOR MANUFACTURING A PACKAGING BY FORMING AND FIXING A BLANK IN SEMI-RIGID MATERIAL - Google Patents

Abstract

The method according to the invention comprises cutting into a substrate (PC) recesses (E1 to E5) in predetermined locations, fixing on the substrate a strip of film of heat-sealable material, at least in the regions where are located the said recesses (E1 to E5), the cutting of a blank on the support / film assembly, so that the cutting at the recesses (E1 to E5) leaves protruding parts of the film and the folding of the blank and the fixing of at least two parts of the blank by thermoforming of at least one protruding part.

Description

- 1 The present invention relates to a method of manufacturing a

  packaging by forming and fixing a blank of semi-rigid material such as cardboard or the like. It also relates to packaging produced in accordance with this process, and, in particular, packaging which may be in the form of boxes produced from a cardboard blank or the like partially covered with a film of heat-sealable plastic material serving to seal the box and / or fix two parts opposite the blank, after

  folding, as well as its inviolability.

  It is known that, in this type of packaging, the fixing of two of its facing parts frequently involves the production of a blank in which the transparent film slightly protrudes from the edge of its cardboard or similar support,

  in predetermined areas of its periphery.

  Thus in particular, the international patent application PCT / FR 01/00635, filed in the name of the Applicant, describes an embodiment in which the protruding part of the film is turned over so as to cover the edge edge as well as a zone of the external wall of the body adjacent to this edge and to ensure a tight fixing of the cover, this projecting part being fixed to

  both on the body and on a cover by heat sealing.

-2

  It turns out that the production of blanks having protruding film portions poses many technical problems which are difficult to dissolve.

  Indeed, theoretically it is necessary to make separate cuts on the cardboard blank and on the film which covers it and then to carry out the fixing of the film on the cardboard in such a way that the protruding parts of the film are well at the desired locations.

  It can be seen in practice that this process cannot be used with the machines usually used in this field. 10 The invention therefore more particularly aims to solve this problem in a relatively simple manner and suitable for industrialization with

high production rates.

  To this end, the method according to the invention comprises the following operating phases: a first phase consisting in carrying out on a substrate such as a sheet or a strip of semi-rigid material from which the blank must be cut, recesses at the locations where the protruding parts must be located, - a second phase of fixing to this sheet or this strip of a film of heat-sealable material, at least in the regions where said cutouts or said recesses are located, - a third blank cutting phase on the assembly formed by the sheet or strip, so that the cutting at the above recesses leaves the above protruding parts of the blank remaining, a folding blank phase and fixing, at least minus two parts of the

  blank, by heat sealing at least one protruding part.

  -3 Of course, the first phase of the process may also include the production of recesses intended to make windows in the packaging a

once assembled.

  Likewise, this first phase may include the formation of pre-cut lines or cutting lines (creasing, perforations, etc.). In this case, the presence of the film on these precut lines will guarantee sealing at this level. The third cutting phase may then include the formation of the precut primer of the film. This solution 10 makes it possible in particular to facilitate the opening of the packaging without thereby

compromise the seal.

  Embodiments of the invention will be described below, by way of nonlimiting examples, with reference to the appended drawings in which FIG. 1 represents a sheet of semi-rigid material in which cuts have been made in accordance at the first stage of

process according to the invention.

  Figure 2 is a blank made from the sheet shown in the

figure 1.

  Figure 3 is a perspective view of a box made from the blank

shown in Figure 2.

  Figure 4 is a partial section illustrating the principle of fixing a

  cover on the body of the box shown in Figure 2.

  Figure 5 is a blank of a box provided with a hanger.

  -4 Figure 6 is a perspective view of the box obtained using the blank

shown in Figure 5.

  Figure 7 is a partial section illustrating the method of fixing the two pads constituting the hanger. Figure 8 is a partial perspective view of another box obtained

  according to the process according to the invention.

  FIG. 9 shows a detail of the blank of the box shown in FIG. 8.

  In the examples represented in FIGS. 1 to 4, the method according to the invention applies to the production of a cardboard box of very simple structure, comprising a tubular body 1, of rectangular section, provided with a window 2 and the two ends 3, 4 of which are closed by two covers

  respective 5, 6 of substantially parallelepiped shape.

  The inner face of the body 1 and that of the covers 5, 6 are covered with a film of a heat-sealable material 7 which seals the box. The body 1 of this box is produced using a blank 8 such as that shown in FIG. 2 which consists of a strip of rectangular cardboard divided into five successive areas P1 to P5 by four successive fold lines LI to L4, the areas PI to P4 constituting the lateral sides of the box. 25 The narrower area 5 constitutes a fixing tab intended to be fixed on the tab P1 by means of a film strip 11 so as to obtain the shape

body tubular 1.

  The fastening of the covers 5, 6 on the body 1 is ensured by means of two strips 30 of film 9, 10 which protrude respectively from the longitudinal edges of the blank 8

  (and therefore the upper and lower edges of the body 1).

-5

  During fixing, the covers 5, 6 come to fit on the body 1. The film strips which protrude from the body 1 are turned over and then overlap on the edges of the corresponding edges and are slightly folded down on the outside face. of body 1 in an area adjacent to the edge.

  As can be seen in FIG. 4, the fixing by heat sealing makes it possible to obtain a sealed fixing at the level of the edge T and of the zone of

  covering R of the external face of the body 1.

  Of course, the film strips which protrude from the body 1 could be turned inward to come to be applied and welded against the bottom of the

cover 5.

  As previously mentioned, the object of the present invention is to facilitate the production of the strips of film projecting from the cardboard blank, so as to be able to ensure industrial production at a rapid rate using

of existing machines.

  In this example, it uses substrates consisting of 20 PC cardboard plates, of standard format, in which it proposes to make two blanks.

  of the type shown in FIG. 2.

  To this end, the manufacturing process comprises, in accordance with the invention: - A first step consisting in producing in the cardboard plate PC recesses E1 to E5 at the locations where the film strips used to fix the box. In this example, three parallel longitudinal recesses E1, E2, E3 and two transverse recesses E4, Es are produced. The central recess E2, which has a width twice that of the recesses E1, E3, is intended to be divided into two -6 to form two strips of films belonging respectively to the two blanks. - A second step during which a heat-sealable film is fixed on one of the two faces of the PC cardboard plate. This sheet therefore extends 5 over the previously made recesses E1 to E5. (It is the same with regard to the windows F, the creasing, the precuts etc ... made during the first step.) - A third step of cutting the contours of the blank, this step including cutting the film areas which extend over recesses E1 to E5 so as to obtain the film strips 9, 10, 11. In Figure 1 the

  cut lines have been shown in broken lines.

  - A fourth step of folding and fixing to obtain the body 1 of the

  box shown in Figure 3.

  This step can also include creasing operations to facilitate subsequent folding, precut operations, areas to be

  easy breaking, etc. It may also include a printing process.

  Of course, between the second and the third step, intermediate steps may be provided, for example printing the

film, creasing etc ...

  An advantage of the process according to the invention consists in that it allows blanks of complex shapes to be produced without increasing the

  complexity and cost of the manufacturing process.

  Thus for example without increasing the number of manufacturing steps, it is possible to produce boxes of the type illustrated in FIG. 6 which is produced using a blank comprising, as shown in FIG. 5: A longitudinal central strip BC comprising five successive areas P6 to P1o, separated by four fold lines Ls to L8, the pages P6 to P9 constituting the four lateral sides of the body of the box

  while the narrower Plo0 area serves as the body's fixing lug.

  Areas P1 to P15 extending transversely areas P6 to P9 of the central band BC, by means of longitudinal fold lines extending along the upper edge of this band BC, namely: areas Pl2, P13 divided into two parts by a longitudinal fold line L9 which extends the area P7 to successively form the top of the box (area P12) and a range for hanging the box (area P13). This area P13 is provided with an obviously ES1, in which a suspension rod can pass, two areas P1, P14 respectively extending the areas P6 and P8 to form reinforcement tabs on the top of the box, a area P15 extending the area P9 to form a lining of the suspension range (range P13), comprising a recess ES2 identical to the recess ES1, ranges P16 to P19 extending transversely the ranges P6 and P9, of the central strip BC by means of lines longitudinal folding LI0 to L13 which extend along the lower edge of the strip BC, namely: P17, P19 areas which extend the areas P7 and P9 to form the bottom and the lining of the bottom of the box respectively, and * P16, P18 tracks which extend P6, P8 tracks respectively

to form two bottom reinforcements.

  In this example, the film strips BF1 to BF4 which protrude from the cardboard substrate are located in the extension of the pads P13, P17, P15 and Po10. The -8 band BF4 is used for fixing the body of the box, the band BF2 ensures the fixing of the bottom while the bands BF1 and BF3 ensure the fixing of the

  suspension range on its support, as shown in figure 7.

  To this end, the two areas P13 and P15 are pressed against each other and the two strips of film BF1, BF3 are turned over on the edges of the two areas P13 and P15 to be fixed, one on the other, against the outside of one

  of these two ranges, here the suspension range P15.

  This solution makes it possible to considerably increase the tear resistance of the suspension pad and its lining between their ES recesses, and their

upper edges.

  In the example illustrated in FIGS. 8 and 9, the box comprises four lateral sides CL extended beyond their upper and / or lower edges by four areas, namely a PLI area, constituting the top of the box, a area PL2, constituting the lining of this range PL1 and two ranges PL3, PL4

  which respectively constitute reinforcements from above.

  This box is made from a blank in which the tracks are separated

  from each other by recesses E, here triangular.

  According to the invention, the film which covers the substrate extends over these recesses E. Thus, during the folding of the blank, the portions of film which extend over the recesses E fold back on themselves and, after the heat sealing, we obtain a continuity of sealing at the junction between the top and

the tubular body of the box.

-9

Claims (11)

claims   1. A method of manufacturing a packaging by forming and fixing a blank comprising a substrate (PC) of semi-rigid material, at least partially covered with a film of heat-sealable plastic (7), which protrudes slightly from the edge of the substrate (PC) in predetermined areas of its periphery, characterized in that it comprises the following operating phases - a first phase consisting in carrying out on a substrate (PC) such as a sheet or a strip of semi-rigid material from which the blank must be cut, recesses (El to E5) at the locations where the protruding parts must be located, - a second phase of attachment to this sheet or strip of a film of heat-sealable material (7 ), at least in the regions where said cutouts or said recesses are located (E1 to E5), - a third blank cutting phase on the assembly constituted by the sheet or strip and the film (7), so that the cutting at the level of the above-mentioned recesses (El to Es) leaves the above-mentioned protruding parts remaining, a phase of folding the blank (7) and fixing, at least two parts of the   blank by heat sealing at least one protruding part.   2. Method according to claim 1, characterized in that the said first phase further comprises the production of recesses intended to make windows (F) in the packaging once assembled.   3. Method according to one of claims 1 and 2,   characterized in that the aforementioned first phase further comprises the production of pre-cut lines or cutting lines on the substrate (PC). - 10   4. Method according to one of the preceding claims,   characterized in that the aforesaid first phase comprises the printing of the substrate (PC).   5. Method according to one of the preceding claims,   characterized in that it comprises, following the second phase, a phase   film printing (7) and / or a creasing phase of the fold lines.   6. Packaging produced in accordance with the process according to one of the previous claims,   characterized in that it comprises a tubular body produced using a blank covered with a film and one edge of which is extended by a strip of film (11) serving to ensure fixing by heat sealing. 15 7. Packaging according to claim 6, characterized in that said edge is a transverse edge of the blank and in that the   film strip (7) is used to secure the body.   8. Packaging according to one of claims 6 and 7,   characterized in that one of the longitudinal edges of the blank is extended by a   film strip of heat-sealable material (El to E3).   9. Packaging according to claim 8, characterized in that the strip of heat-sealable material (E1 to E3) is folded over the edge of the blank and on its opposite face so as to ensure a   waterproof fixing with a cover.   10. Packaging according to one of claims 6 to 8, a range of 30 above is extended by a suspension range (P13) and one of the faces   - the side of the body is extended by a pad (P15) serving as a lining for the hanging pad, characterized in that the upper edges of the hanging pad and the lining pad are extended by two strips of film (BF1, BF3) made of heat-sealable material, these two strips (BF1, BF3) being turned over so as to be fixed one on the other against the external face of one of these two pads.   11. Packaging according to one of claims 6 to 8,   characterized in that it comprises lateral sides (CL) extended beyond their upper edges and / or lower areas (PL1 to PL4) separated from each other by recesses (E) through which extend portions of said film, and in that the heat-sealing of these film portions ensures, in addition to the fixing of said areas, a continuity of sealing at the junction between said areas (PL1 to PL4) and said lateral sides (CL) .