APPARATUS FOR PACKAGING AN ARTICLE BY MEANS OF HEAT-SHRINKABLE FILM

Abstract: An apparatus for packaging an article by means of heat-shrinkable film (19) comprises, in combination, first support means adapted to support a reel (14) of the said film, a device for sealing (20) the film wrapped around the article to be packaged, an air heating chamber, and second means for placing into and removing from the said chamber the article contained within the said film. The said chamber has a substantially box-shaped configuration and is self-bearing, and with respective walls thereof there are associated the said first support means, the said sealing device and the said second means of placement and removal.

Description: The present invention relates to an apparatus for the packaging and sealing of an article within heat-shrinkable film of the so-called "centerfolded" type. The apparatus according to the invention is particularly, but not exclusively, adapted for packaging books, magazines, office files, table, correspondence and all other papers requiring to be stored, despatched or sealed, also for purposes of secrecy. Different kinds of apparatus for packaging material inside heat-shrinkable film are known. A first type of apparatus consists structurally of the combination of a film sealing device between the opposite faces of which the article to be packaged has been placed, and a tunnel in which the film is heat-shrunk onto the article. The film sealing device (sealing rod type) and the tunnel are disposed in-line and the article is fed through the tunnel by means of a conveyor, generally a roller conveyor. Packaging apparatus of such type normally have a large bulk dimensions and are suitable for high outputs and for the packaging mostly of relatively large articles. In other type of packaging apparatus the sealing rods of the sealing device are incorporated in a closure of a chamber in which the heat-shrinking of the film is also performed by means of forced hot air circulation. Such kind of packaging apparatus is for example described in italian patent 1024614, EP-A-0111369 and EP-A-0184524, from which the relevant technology may be better understood. Although it can be relatively small in size and is very satisfactory in operation, a packaging apparatus embodied according to italian patent 1024614 can be used in a manner such as to achieve operating speeds that counsel its use in certain specific sectors. The prior art part of claim 1 is based on this document. If used to package a small number of articles per day, its potential is wasted, and in some cases it may prove unwieldy. The object of the present invention is to embody a packaging machine that has a highly compact structure, is economical to construct, extremely dependable in use and that can find a justified use even for relatively low outputs. The said object is achieved by an apparatus for packaging an article by means of heat-shrinkable film according to the annexed claim 1. The functional and structural characteristics of the invention, and its advantages over the known art, will become more apparent from an examination of the following description, referred to the appended drawings which show an example of a packaging machine incorporating the innovative principles of the invention. In the drawings: Figure 1 is a lateral elevation showing the sealing area of the packaging machine in question; Figure 2 is a lateral elevation showing the part of the machine opposite that shown in Figure 1; Figure 3 is an elevational view taken through the arrow F of Figure 1; Figure 4 is an elevational view taken through the arrow F1 of Figure 1; Figure 5 is a longitudinal section taken on the line V-V of Figure 4; Figure 6 is a section taken on the line VI-VI of Figure 1; and Figures 7 to 11 are diagrammatic views showing the manner of operation of the machine illustrated in the previous Figures. With reference to the drawings, the machine in question is indicated overall by 10 and consists structurally of an air-heating chamber and, preferably but not necessarily, means for forced circulation of the heated air, such means being in the form of a box-shaped self-bearing body which, in the example shown, is generally dihedral in shape and rests on adjustable feet 12. The top wall 13 of the chamber 11 carries a device for supporting and feeding a reel 14 of plastic film of the so-called "centerfolded" type: the said device can consist simply of a cradle formed by a pair of freely rotatable wheels 15 mounted on a slide 16 coupled to lateral guides 17. In this manner the slide 16 can be translated along the guides 17 to adjust the position of the reel 14 of film with respect to the sealing device hereinafter described, in relation to the dimensions of the article to be packaged. On the side wall 18 of the body 11 is mounted a device for sealing the plastic film 19, the said device being indicated overall by 20. The general structure of the device 20 is per se known, and comprises a pair of electrical sealing resistances, at right angles one to the other and pivoted at 21 to the wall 18 of the body 11. Cooperating with the resistances 20 are respective backing plates 22 and a pair of bars 23 which are also disposed at right angles to each other and are position-wise adjustable through the agency of an adjustement screw 24. The bars 23 (the horizontal one of these having the form of a shelf to support the article) thus form a wrap-and-support section for the article to be packaged, which is placed between the faces on the film 19 and rested on the horizontal shelf-shaped bar 23 (Figure 8). Within the chamber 11, on its backwall 25, there is mounted at least a fan 26 which causes forced circulation of the air inside the chamber 11, which air is heated by means of an electrical resistance 27 supported above the fan 26. It is noteworthy that the disposition of the fan 26 and resistance 27 can be other than that shown. The fan 26 could for instance be mounted at the top of the chamber 11 with the resistance 27 below it. A disposition of the complex on one side of the chamber can also be contemplated. The numeral 28 indicates overall a basket with wheels 29 which are adapted to be coupled to guides 30 provided inside the chamber 11 above the ventilar 26/resistances 27 ensemble. The basket 28 can in this way be placed into and supported within the chamber 11, and removed therefrom, through a window 31 in the wall 32. The numeral 33 indicates a service board extending from the body 11, on the side opposite the sealing device 20. The manner of operating of the packaging machine heretofore described will become apparent from an examination of Figures 7 to 11. As is shown in Figure 7, when the electrical sealing resistances 20 are raised (by the agency of a handle) with respect to the wall 18, a section of centerfolded film 19 is manually hauled into the sealing area between the rods 23. The article to be packaged, for example a book 33, is inserted between the two faces of the film 19 and rested on the horizontal shelf-shaped bar 23 (Figure 8); the sealing resistances are then lowered, as shown in Figure 9, against the backing plates 22, and in this way the two opposite surfaces of the film 19 are sealed together and the resulting envelope proves separated from the rest of the film 19. The said envelope containing the book 34 is removed from the sealing device and placed, either by itself or with other previously packaged books, inside the basket 28 which is introduced (Figure 10) into the heat-shrinking chamber 11 through the window 31. At this point the fan 26/resistances 27 ensemble comes into operation, with the result that hot air is force-circulated within the chamber so as to cause the plastic film to heat-shrink onto the article contained in it. The apparatus in accordance with the invention is thus seen to be highly compact, can be constructed at very reasonable cost and can therefore find justified use also for relatively lowoutputs. The construction described is illustrative and not limiting, and variants and modifications of it hat fall within the scope of the claims can be freely made to it. For example instead of a manual basket, provision can be made for an automated conveyance system that conveys through the heat-shrinking chamber the package sealed by the sealing device and expels it when heat-shinkage has taken place. In addition, the heat-shrinking can also be performed without the aid of forced air circulation, and in such case the fan would be omitted. Noteworthy, lastly, is the fact that the basket can be interchangeable with other of different configuration, in relation to the article to be packaged. Fur such purpose the wall 32 will also be interchangeable with another having a window shaped to match the shape of the basket.

Claims: 1. A compact machine (10) for packaging articles in two-ply heat-shrinkable film comprising a box-shaped housing having vertically extending side walls (18), a top wall (13) and a bottom wall (25) and defining therein a thermal shrinking chamber (11), a support means mounted on the housing for rotatably supporting a roll (14) of the two ply heat-shrinkable film so that it can be pulled over one wall (18) of the housing, sealing means (20) pivotally mounted on one wall for sealing at least one edge of said film (19) together and for separating the wrapped article from the roll (14) of film (19), heating means (27) for heating the air within said chamber (11), an openning (31) in the housing for access to the chamber (11), a door for closing the opening (31) and means (33) for holding in the chamber the wrapped article separated from the film (19) in the chamber, characterised in that the roll support means is mounted on the top of the housing so that the film can be pulled down over one side wall (18) of the housing, in that it comprises a support (23) on the outside of said one side wall (18) of the housing for holding an article that has been inserted between plys of the film (19), in that the sealing means are mounted on said one side wall (18) adjacent the support (23), in that the opening (31) is located in a side wall (32) which is different from said one side wall, and in that the holding means 33 is adapted to be inserted into and supported within the chamber (11) and removed therefrom through said opening (31). 2. The machine of claim 1, characterized in that said film is a two ply centerfolded film (19) and the sealing means comprises a pair of electrical resistance sealing bars (20) connected at right angles to one another and pivotally mounted at one end of the housing, one bar being located opposite the centerfold and the other perpendicular to the fold and opposite a sealed edge of the film (19) from the preceding sealing step so that the wrapped article when it is sealed by the sealing bar is enclosed on four sides. 3. The machine of claim 1, characterized in that said holding means comprises a basket (28) for holding the wrapped article having wheels (29) and guides (30) located in the chamber (11) that cooperate with the wheels to support the basket in the chamber and guide it into and out of the opening (31). 4. The machine of claim 1, characterized in that said heating means comprises an electric resistance heating element (27) and a fan (26) for circulating the heated air within the chamber (11).

Inventors: DI BERNARDO, PIETRO
Applicants: INTERDIBIPACK S.P.A.
Application year: 1988
Main classification: B65B53
IPC codes: B65B53