EP0184524B1 - Machine for packaging products in a heat-shrinkable film - Google Patents

Description

The invention relates to a machine for packaging various products in a shrink film.

It is well known to package various products such as food products, printing or stationery items or mechanical parts in heat-shrinkable films, welded on their edges.

• - une bobine de film dossé à double épaisseur,
• - un moyen, tel qu'une épingle ou analogue, pour écarter les deux épaisseurs de ce film et disposer entre celles-ci le produit à emballer,
• - un poste de soudure où l'on soude bord à bord la périphérie des deux épaisseurs du film autour du produit à emballer;
• - un poste de rétraction où l'ensemble est soumis à un traitement thermique provoquant la rétraction du film autour du produit dont il épouse ainsi les formes.

A machine of the type in question essentially comprises:

• - a roll of double-layered film,
• a means, such as a pin or the like, for separating the two thicknesses of this film and placing the product to be packaged between them,
• - a welding station where the periphery of the two thicknesses of film is welded edge to edge around the product to be packaged;
• - a shrinking station where the assembly is subjected to a heat treatment causing the shrinkage of the film around the product of which it thus follows the shapes.

• - une table fixe de travail perforée destinée à recevoir le produit dans son emballage à rétracter;
• - une cloche, articulée autour d'un des bords de la table de travail et dont deux bords adjacents formant un L comportent des résistances électriques de soudure;
• - un dispositif de chauffage, associé à un ventilateur, disposé de l'autre côté de la table de travail perforée.

In the US patents US-A-4 104 848 and 4162 604, a machine of the type in question has been proposed in which the welding station and the shrinking station are grouped in a single work station. This single workstation essentially includes:

• - a fixed perforated work table intended to receive the product in its packaging to be retracted;
• - a bell, articulated around one of the edges of the work table and two adjacent edges of which form an L include electrical welding resistors;
• - a heating device, associated with a fan, arranged on the other side of the perforated work table.

In this rather bulky arrangement, the articulated bell being most generally opaque, during the entire welding and shrinking operation, the product to be packaged is thus hidden from the view of the operator and does not allow this operation to be controlled, especially to intervene if necessary. In addition, when the operator raises the articulated bell, once the operation is finished, the hot air contained in this bell rises to his face, which is unpleasant. Finally, whatever the dimensions of the product to be packaged, it is necessary for each operation to heat the entire internal volume of the bell, which therefore constitutes a significant and unnecessary expense.

The invention overcomes these drawbacks. It targets a packaging machine of the type in question in heat-shrinkable film which is compact, economical to build and operate, allows the product to be viewed throughout the critical shrinkage phase, allows the operator to intervene if takes place during this phase, and finally can be easily implemented even by inexperienced personnel.

• . une bobine d'alimentation pour un film plié, souple, à double épaisseur, destiné à emballer un produit,
• . des moyens pour écarter les deux épaisseurs de ce film,
• . des moyens pour souder en périphérie le film bord à bord, lesdits moyens de soudage étant constitués par un cadre dont deux côtés contigus en forme de L comportent des résistances électriques chauffantes, ledit cadre étant relevable autour de l'axe longitudinal parallèle à la table,
• . des moyens pour rétracter le film autour du produit à emballer,
  dans laquelle les moyens de soudage et de rétraction sont groupés en un seul poste de travail sur une table fixe,
  se caractérise en ce que le moyen de rétraction est constitué par un portque mobile disposé au dessus de la table fixe, ledit portique étant equipé d'une source d'air chaud dirigé vers la table, et étant susceptible:
• - d'une part, de coulisser horizontalement le long de la table fixe pour balayer la surface du produit à rétracter après soudage bord à bord;
• - et d'autre part, de pivoter dans un plan orthogonal par rapport au plan de la table.

This improved machine for packaging products in heat shrinkable film, of the type comprising:

• . a supply reel for a folded, flexible, double-thickness film intended for packaging a product,
• . means to separate the two thicknesses of this film,
• . means for edge-to-edge welding of the film, said welding means being constituted by a frame, two contiguous L-shaped sides of which include electric heating resistors, said frame being liftable around the longitudinal axis parallel to the table,
• . means for shrinking the film around the product to be packaged,
  in which the welding and shrinking means are grouped in a single work station on a fixed table,
  is characterized in that the retraction means is constituted by a movable portque disposed above the fixed table, said gantry being equipped with a source of hot air directed towards the table, and being susceptible:
• - On the one hand, to slide horizontally along the fixed table to sweep the surface of the product to be shrunk after welding edge to edge;
• - And secondly, to rotate in a plane orthogonal to the plane of the table.

In other words, the invention consists in using in the single workstation as a means of retraction, no longer an articulated bell but a heating gantry, also articulated, but which moreover makes it possible to sweep the entire surface of the product to wrap.

• - le portique mobile comprend:
• . un bras transversal creux, ouvert sur la face en regard de la table, articulé autour et le long d'un axe longitudinal parallèle au bord de la table, ledit bras creux étant relié à un ventilateur soufflant de l'air sur des résistances chauffantes placées dans ledit bras creux,
• . et une poignée de manoeuvre placée à l'extrémité du bras creux opposée à celle recevant l'axe d'articulation, destinée à permettre l'actionnement de ce bras le long et autour de cet axe;
• - ledit axe longitudinal parallèle à la table sert de guidage à léxtrémité du portique mobile relevable, tandis que l'extrémité opposée de ce portique est guidée dans une glissière longitudinale prévue à cet effet dans le cadre;
• - la table de travail est constituée par une brille métallique réglable en hauteur par rapport au portique mobile ; - le portique mobile de rétraction, coulissable et relevable le long de l'axe longitudinal parallèle à la table, solidaire du cadre de soudure,
• comprend:
• . un ventilateur,
• . deux bras transversaux creux parallèles, disposés de part et d'autre de la table grillagée, chaque bras comportant:
  • x un conduit pour le relier au ventilateur,
  • x une résistance électrique chauffante,
  • x une fente longitudinale disposée en regard de la grille de travail, destinée à diriger l'air chaud soufflé sur les films soudés a rétracter, disposés autour du produit à emballer,
  • x une poignée de manoeuvre, fixée à l'extrémité du bras supérieur, destinée, après soudure bord à bord des deux épaisseurs du film, à permettre le coulissement longitudinal du portique mobile le long et autour de cet axe longitudinal parallèle à la table de travail.

Advantageously, in practice:

• - the mobile gantry includes:
• . a hollow transverse arm, open on the opposite face of the table, articulated around and along a longitudinal axis parallel to the edge of the table, said hollow arm being connected to a fan blowing air on heating resistors placed in said hollow arm,
• . and an operating handle placed at the end of the hollow arm opposite to that receiving the articulation axis, intended to allow the actuation of this arm along and around this axis;
• - Said longitudinal axis parallel to the table serves as a guide at the end of the lifting mobile gantry, while the opposite end of this gantry is guided in a longitudinal slide provided for this purpose in the frame;
• - the work table is constituted by a metallic shine adjustable in height with respect to the mobile gantry; - the mobile retraction gantry, sliding and lifting along the longitudinal axis parallel to the table, integral with the welding frame,
• includes:
• . a fan,
• . two parallel hollow transverse arms, arranged on either side of the mesh table, each arm comprising:
  • x a duct to connect it to the fan,
  • x an electric heating resistance,
  • x a longitudinal slot arranged opposite the working grid, intended to direct the hot air blown onto the shrink-welded films, arranged around the product to be packaged,
  • x an operating handle, fixed to the end of the upper arm, intended, after edge-to-edge welding of the two thicknesses of the film, to allow the longitudinal sliding of the mobile gantry along and around this longitudinal axis parallel to the work table .

The manner in which the invention can be implemented and the advantages which ensue therefrom will emerge more clearly from the exemplary embodiments which follow, given by way of indication and without limitation.

Figures 1 and 2 show in summary perspective view a first embodiment of a machine according to the invention shown in two successive operating phases, respectively open (Figure 1) for the introduction of the product to be packaged, then closed (Figure 2) for the welding and shrinking operation.

Figure 3 is a cross-sectional view of another preferred embodiment of the invention.

Figure 4 is a section along the axis IV-IV '.

The packaging machine according to the invention essentially comprises a metal frame (1), carrying at one end a fixed arm (2) intended to receive a reel (3) of a heat-shrinkable film (4), folded in a U (folded ) double thickness (5) and (6), for example polyvinyl chloride. By unwinding, the two thicknesses (5) and (6) of the film (4) pass respectively below and above a transverse pin (7) of separation fixed on one side of the frame (1), so as to move aside in order to receive the product (8) to be packaged. The upper part of the frame (1) forms a work table designated by the reference (9). This work table (9) is equipped with a lateral longitudinal axis (10) oriented perpendicular to the direction of the transverse pin (7) and parallel to the edge of the table (9). On this longitudinal axis (10), a hinged frame (11) is articulated whose internal face of two contiguous sides (12, 13) carries heating resistors, making it possible to weld edge to edge the two sheets (5) and (6) on either side of the object (8) placed on the table (9).

The folding frame (11) comprises, parallel to and opposite the axis (10), a guide rail (14) in which slides the corresponding lower end (15) of a mobile gantry ( 16). The opposite end (17) of the gantry (16) slides by a sleeve (18) along the axis (10).

Near the slide (14), the gantry (16) has a control handle (19).

According to the characteristics of the invention, the mobile gantry (16) arranged parallel and above the table (9) is equipped with a blower (20), connected by a conduit (21) to a hollow arm (22) in which is arranged an electric heating resistor (23). This transverse hollow arm (22) is open on the opposite face of the table (9) to thus form a ramp capable of blowing hot air downwards, as indicated by the arrows (24).

On its front part, the frame (1) also includes a control console (25).

To pack a product such as for example a book (8), the operator raises the frame (11) (Figure 1). He pulls a length of the two thicknesses (5) and (6) to the top of the work plate (9) and places the delivery (8) between these two thicknesses, the assembly resting on the table (9).

The operator then lowers the frame (11) (Figure 2). By acting on the organs of the desk (25), it activates the heating resistors (12, 13) to cause around the book the edge-to-edge welding of the sheets (5) and (6) and thus the cutting. Immediately after, and without having to move the frame (11), the operator acts on the handle (19) to advance the gantry (16) as indicated by the double arrow (26). Thus, the mobile gantry (16) sweeps the upper space of the table (9) by blowing hot air, as indicated by the arrows (24), in the direction of the book (8) to be packaged. This causes the films welded around the book to shrink (8).

When he raises the frame (11), the operator only has to grab this book (8) duly packaged.

In the preferred embodiment shown in FIGS. 3 and 4, the machine according to the invention essentially comprises a metal grid (30) intended to form a work table for receiving the product (8) to be packed in the two thicknesses (5) and (6). This grid (30) is adjustable in height relative to the mobile gantry, thanks to notches (31) provided for this purpose. As in the previous embodiment, the mobile gantry (16) is integral with the welding frame (11). This mobile retraction gantry essentially consists of a fan (20) arranged at the longitudinal axis (10) parallel to the work table (9), connected by two conduits (32, 33) to two hollow arms ( 34, 35) parallel arranged on either side of the grid (30). Each of these two hollow arms (see Figure 4) (34.35) has a heating plate (36) around which the electrical resistance is wound. The face of each of these arms opposite the grid (30) has a longitudinal slot (37) intended to receive a distribution and protection grid for the hot air blown by the fan (20) and as indicated by the arrows (24). The fan (20) is started automatically when the welding frame (11) is closed, in particular by pressing a contact placed for this purpose on the work table (9). Similarly, during this closing operation, the upper arm (35) articulated around the axis (10) comes to coincide by its conduit (33) with the fixed conduit (32) of the fixed lower arm (34). The assembly of the two arms respectively fixed (34) and articulated (35) is thus secured. In this way, by sliding the handle (19) in the slide (14) of the frame (11), we move well the entire shrink assembly around the product (8) to be packaged.

Thus, all the welding and shrinking operations are carried out not only on a single workstation, but entirely under the eyes of the operator, which thus allows complete control of this operation.

• - un encombrement réduit;
• - la possibilité d'être mis en oeuvre par un personnel non qualifié et non expérimenté;
• - une grande souplesse de manipulation;
• - le fait que pendant toute l'opération, les produits à emballer restent visibles, ce qui permet à l'opérateur s'il y a lieu d'intervenir;
• - l'absence de désagréments pour l'opérateur qui ne reçoit plus au visage une bouffée d'air chaud;
• - la simplicité de construction et de mise en oeuvre;
• - la possibilité d'emballer des petits paquets, puis seulement ensuite d'effectuer la rétraction de ces paquets groupés sur la même table de travail, ce qui permet ainsi d'augmenter les cadences et de diminuer le prix de revient.

The device according to the invention has numerous advantages over known solutions, in particular those mentioned in the preamble. We can cite:

• - reduced dimensions;
• - the possibility of being implemented by unqualified and inexperienced personnel;
• - great flexibility of handling;
• - the fact that during the entire operation, the products to be packaged remain visible, which allows the operator to intervene;
• - the absence of inconvenience for the operator who no longer receives a breath of hot air in the face;
• - the simplicity of construction and implementation;
• - the possibility of packing small packages, then only then to carry out the retraction of these packages grouped on the same work table, which thus makes it possible to increase the rates and reduce the cost price.

In this way, this machine can be advantageously used for packaging various products, such as printing articles: books, magazines, albums, archives, stationery, small mechanical parts, various samples: cosmetics. , toys, food items, etc.

Claims (5)

1. Machine for packaging products (8) in thermoretractable film (4), comprising:

- a fixed working table (9);

- a roll (3) supplying a film (4) folded soft in two layers (5, 6) for wrapping a product (8) on said table (9);

- means (7) for separating the two layers (5, 6) of said film (4) for introducing the product (8) to be packaged;

- means (12, 13) for welding the periphery of said film (4) edge-to-edge, comprising a welding frame (11) of which two L-forming contiguous sides (12, 13) present electric heating elements for welding, said welding frame (11) being tiltable about a longitudinal spindle (10) parallel to the said table (9);

- means for retracting the film (4) about the product (8) to be packaged;

- and in which machine the welding and retracting means are gathered into one working station on said fixed table (9);
wherein the retraction means includes a movable crane (16) disposed above the fixed table (9), and is equipped with a source of hot air (20), directed (24) towards the table (9), and is able:

- on the one hand, to slide horizontally along the fixed table (9), so as to sweep the surface of the product (8) to be packaged after edge-to-edge welding;

- on the other hand, to pivot inside an orthogonal plane with respect to the plane of the table (9).

2. Machine for packaging according to claim 1, wherein the movable crane (16) comprises:

- a hollow tranverse arm (22, 34, 35), open (37) on its face opposite to the table (9), articulated around and along a longitudinal spindle (10) parallel to the edge of the table (9), said arm being connected (21, 32, 33) to a blowing means (20) blowing air on electric heating elements (23, 36) located in said hollow arm (22, 34, 35);

- and an operating handle (19) located at the end of said hollow arm (22, 35) opposite to the end receiving the articulated spindle (10), and designed to allow the operating of the movable crane (16) along and around said spindle (10).

3. Machine for packaging according to one of the claims 1 and 2, wherein the longitudinal spindle (10), parallel to the table (9), is also used for guiding the end of the movable adjustable crane (16), whereas the opposite end (15) of this crane (16) slides in a longitudinal guiding rail (14), provided for that use in the frame (11).

4. Machine for packaging according to one of the claims 1 to 3, wherein the working table (9) includes a metallic grid (30), adjustable in height (31) in respect to the movable crane (16).

5. Machine for packaging according to the claim 4, wherein the retraction movable crane (16), slidable and adjustable along the longitudinal spindle (10), parallel to the edge of the working table (9), jointed to the welding frame (11), comprises:

- a blowing means (20);

- two parallel and hollow tranverse arms (34, 35), placed on either side of the grid table, each hollow arm (34, 35) comprising:

. a conduit (32, 33) connecting it with the blowing means (20);

. an electric heating element (36);

. a longitudinal slot (37) situated opposite to the working grid (30) and designed to direct (24) blown hot air onto the faces (5, 6) of the film (4) to be retracted, welded around the product (8) to be packaged;

. an operating handle (19) fixed at the end (15) of the superior arm (35), designed after welding edge-to-edge (12,13) of the two faces (5, 6) of the film (4), to allow the longitudinal sliding of the movable crane (16) along and around the longitudinal spindle (10) parallel to the edge of the working table (9).

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