DESCRIPTION

Technical Field

The present invention relates to the field of filling plants for filling plastic bottles, especially, but without limitation, disposable bottles. The object of the present invention is a machine for closing plastic bottles.

State of the Art

Small disposable bottles have been marketed for many years, for instance for containing medicines and similar products.

The most known bottles of this type are vials made of glass, a material allowing optimal inertness with the product contained therein.

Usually, these bottles are produced in the following way: the bottles are molded with an open end, then they are loaded in a filling line where, arrange don a moving line, they move towards a filling station and then a closing station where the open end is closed.

The closing step is a critical step in this process. Namely, it should be as sterile as possible, to prevent impurities from entering the bottle.

In the last year small plastic bottles have been increasingly used to contain medicines and the like.

The bottle closing step may provide for a step of heating the open end of the bottles and the subsequent closing by means of jaws holding the opposite parts of the open end of the bottles.

With the traditional sealing methods it is often impossible to seal the openings of bottles made of particularly rigid material. The actually used systems have several drawbacks, indicated below.

For the glass vials open flames are used to fuse he glass and to seal the top part of the vial. Open flames cannot be used for plastic vials/bottles, as they would burn the plastic, generating toxic and carcinogenic substances.

For strip disposable tubes or small bottles, i.e. bottles joined to one another in series, or for toothpaste tubes, sealing plates are used, fusing and modelling the opening of the bottle from opposite sides; then, two cold jaws give the shape and seal. This is possible only if the bottle plastic is sufficiently soft, as the bottles deform under the pressure of the hot pliers and the whole surface adheres to the pliers hot surface.

If the bottles are made of rigid plastic, this system cannot be used as the rigid plastic does not deform and, therefore, it does not come into contact with the hot surface, and therefore the heat is not distributed on the whole part to be sealed; moreover, if the pressure of the hot plates is increased, the bottle could break.

Other heating systems provide for hot air blows directed onto the open end of the bottles, so as to fuse the plastic. However, this process is not suitable for the pharmaceutical field, as hot air (passing through hot resistances) could bring with itself foreign parts from the hot metal that tends to oxidize under high temperatures. Moreover, the blows shall be directed towards the inner walls of the bottles to facilitate seal, and therefore they act on the product contained therein, with the risk of altering the features thereof.

Object and summary of the invention

The object of the present invention is to provide a machine for closing plastic bottles, that overcomes the drawbacks described above.

Within the scope of this object, an important object of the present invention is to provide a machine for closing bottles made of particularly rigid plastic.

A further important object of the present invention is to provide a machine for closing plastic bottles, allowing a high sterility degree.

A further object of the present invention is to provide a machine for closing plastic bottles, allowing a more economical production.

These and other objects, that will be more apparent from the description below, are achieved by means of a machine for closing plastic bottles, comprising a moving line for moving open bottles, heating means being provided along said line for heating the open ends of said bottles, and, downstream of said heating means, sealing means for closing said open ends of said bottles, characterized in that said heating means comprise at least one infrared heater arranged along said moving line.

The machine is particularly useful for disposable bottles, i.e. single-dose bottles, but it could be also advantageously used for multi-dose bottles.

Thanks to the machine for closing plastic bottles by means of infrared heaters, many advantages can be achieved with respect to the current traditional machines, among which those listed below.

Maximal sterility: the bottle, from the moment it is inserted in the machine until it is closed, does not come into contact with mechanical parts arranged above, that could generate particles, deviate and pollute the product as the heaters do not block the laminar flow.

Moreover, the heaters can be mainly made of glass or ceramic, that are highly sterile.

Decrease in the production costs: the pre-heating stations are no longer needed, as well as the sealing plates, this resulting in the elimination of four processing stations that are particularly expensive. The machine cost is likely to be reduced by approximately 40%, with, at the same time, an increase in the performance thereof.

Increase in the production rate: by eliminating many complex parts of the machine it is possible to produce plants with reduced bulk (and therefore more suitable for a sterile packaging environment), thus increasing the production rate.

Reduction of costs for the different formats: it is no longer necessary to produce heating plates and blowing systems according to the bottle shape and dimension.

Processing of particularly rigid plastic: with the traditional systems the (cold) bottle is held by means of red-hot plates. As a result, breakages or crack in the bottle may occur, as the bottle is not enough softened to be suitable to an optimal processing and forming. Thanks to the use for infrared heaters this does not occur, as the invention is based on heating without contact, thus making the plastic uniformly softer in every part. It should also be taken into account that the bottles are mainly circular or oval, therefore with the plates it is impossible to have heat transfer without deforming the container and, if the container is not soft, cracks tend to be formed.

Thanks to the heating method, it is possible to heat the bottle in a decreasing manner from the side of the sealing-closing towards the bottle body. When it is formed (closed), the plastic is deformed gradually; the sealing are therefore visually more pleasant with respect to the sealing made by means of plates, that have the disadvantage of heating a very specific and delimited part of the bottle, that (in closing-molding) does not close/form in a homogenous way. This causes visible cracks, or even holes below the sealing.

A further advantage is the simple start-up and the simple change of format. By decreasing the parts to be replaced, and therefore the parts to be set, the machine is significantly simpler to be managed by the operator.

Thanks to the machine for closing multi-dose or single-dose plastic bottles by means of infrared heaters according to the invention, the startup times are significantly reduced. As there are no plates and bodies to be heated, it is not necessary, for the production, to heat them. The lamps are switched on in a couple of seconds, while the heating of the traditional plates varies according to the model, from ten to forty minutes,

Moreover, every time there is an alarm during production (the emergency button is pushed or the prevention protections are opened as required by law) the red-hot plates may cool, as the power to the plates shall be shut off (as required by law). This result in more time to heat the plates again.

These drawbacks in the production are completely avoided thanks to the machine with infrared heaters.

The machine for closing multi-dose or single-dose plastic bottles through infrared heaters according to the invention also has a sustainability and maintenance coefficient different than that of the traditional system. As the machine as a lower number of parts, and in particular of movable parts and heating parts, maintenance is significantly reduced and therefore the associated costs, also because these parts are very expensive.

The infrared heaters are extremely economical, simple and fast to be replaced.

Moreover, there is a reduction of costs both in the electric and electronic component. Namely, with reference to the forming red-hot traditional plates again, in the invention, as it is no longer necessary to maintain a constant temperature for the plates, and to manage a machine with three sealing/closing stations and one blowing station, the following parts are eliminated (as no longer necessary for the production): resistances to heat the plates (one for each plate and two for the pre-heating), temperature sensors, temperature regulators, static relays, electro-valves for moving the stations, different inlets and outlets of a PLC for controlling the stations.

Preferably, in the machine for closing plastic bottles according to the invention, said at least one infrared heater comprises at least an infrared lamp or at least an infrared radiant strip or panel.

Preferably, the at least an infrared lamp or at least an infrared radiant strip or panel comprise a radiant surfaces made of one of the following: glass, preferably quartz glass, ceramic.

Preferably, the machine comprises a plurality of heating stations arranged in sequence and provided with said infrared heaters.

Preferably, the machine comprises at least one said infrared heater, arranged above on a side of said line, near said bottles, and suitable to heat a plurality of said bottles on said line.

Preferably, the machine comprises at least a pair of said infrared heaters, arranged on opposite sides of said line, near said bottles, and facing each other, and suitable to heat, from opposite sides, a same plurality of said bottles aligned on said line.

Preferably, the machine comprises at least one said infrared heater, arranged above sdaid line, near said bottles, and suitable to heat a plurality of said bottles on said line.

Preferably, the machine comprises at least one said infrared heater, arranged above said line, so as to surround one or more of said bottles.

According to preferred embodiments, the machine according to one or more of the previous embodiments, comprises a filling station for filling said bottles arranged upstream of said bottle heating means.

According to preferred embodiment, the sealing means for closing said open ends of said bottles comprise two opposite jaws, heated if necessary, suitable to be pushed against each other when the open end of at least one said bottle is between them, the open end being plastically deformed, thus closing the bottle opening.

According to preferred embodiments, the sealing means for closing said open ends of said bottles comprise a concave closing body suitable to be pushed, with its concavity facing said open end of the bottle, onto said open end, deforming it plastically and thus closing it.

According to preferred embodiments, the bottles are axially-symmetrical.

According to preferred embodiments, the machine comprises a rotation deice for rotating each bottle around its axis so as to allow a homogenous heating of the open end by means of the adjacent heating means.

According to preferred embodiments, the bottles being processed are vials comprising a base cylindrical body, from which a tapered portion extends, ending in said open end that shall be sealed.

According to preferred embodiments, the bottles are disposable.

According to preferred embodiments, the bottles have the following dimensions: width comprised between 0.5 cm and 2 cm, depth comprised between 0.5 cm and 2 cm, height comprised between 1 and 10 cm.

Brief description of the drawings

Further characteristics and advantages of the present invention will be more apparent from the description of a preferred, although not exclusive, embodiment, illustrated by way of non-limiting example in the attached tables of drawings, wherein:

figure 1 is the layout of a machine according to a first embodiment of the invention;

figure 2 is the layout of a machine according to a second embodiment of the invention;

figure 3 is the layout of a machine according to a third embodiment of the invention;

figure 4 is a schematic view of a row of bottles during the processing by means of the machine according to the invention;

figure 5 is a schematic view of a first example of portion of heating station of a machine according to the invention, wherein the bottles are vials, and there is only one infrared lamp;

figure 6 is a schematic view of a second example of portion of heating station of a machine according to the invention, wherein the bottles are vials, and there are two opposite infrared lamps;

figure 7 is a schematic view of a plastic vial heated by means of a toroidal infrared heater surrounding almost the whole opening of the vial, in a machine according to the invention;

figure 8 is a schematic view of a plastic vial heated by means above which there is a concave closing body suitable to close the open and heated end of the vial, in a machine according to the invention;

figure 9 shows the closing body of figure 7, with the indication of the inner shape;

figure 10 shows a linear infrared lamp usable in a machine according to the invention;

figures 11 and 12 show two infrared heaters so shaped as to surround partially the sides of the bottles, in a machine according to the invention;

figures 13 and 14 show a schematic view of a plastic vial associated with means for the rotation thereof around its main axis, in a machine according to the invention.

Detailed description of an embodiment of the invention

With reference to the above cited figures, a machine for closing plastic bottles according to the invention is indicated as a whole with number 10.

This machine 10 comprises a moving line 11 for the open bottles F, along which several processing stations are arranged, among which, in series, a bottle loading station 12, a filling station 13 for filling the bottles with the product, for example a liquid, a plurality of heating stations 14 (that can also be intended as a single heating station comprising more substations equal to one another and arranged in series), a bottle closing station 15, that can give the final shape to the bottles.

Figure 2 shows a further embodiment of a machine according to the invention, with a different layout that that of figure 1. In this case, the machine is provided with two parallel moving lines 11 for the bottles, arranged like a U, two loading stations 12, two filling stations 13, two plurality of heating stations 14 and two closing stations 15.

Figure 3 shows a further embodiment of a machine according to the invention, with a different layout that that of figure 1 and figure 2. In this case, the machine provides for a circular moving line 11 for the bottles; more in particular, the line is defined by a rotating table or carousel 11A), on which the supports for the bottles are provided, the bottles thus rotating from a station to the other, a loading station 12, a filling station 13, a plurality of heating stations 14, a closing station 15. An unloading station 121.

In this examples, the bottles F are small disposable bottles joined to one another in strips S that shall be filled with a solution, for instance a drug.

Figure 4 schematically show the different processing steps,

(a) the strip S with the bottles F is loaded on the moving line d (with the bottles provided with open upper ends F1);

(b) the bottles are filled in the filling station 13 by means of dosing means

13A;

(c) the strips S pass through three heating stations, where a pair of infrared lamps 14A are arranged on opposite sides of the line 11 , facing each other, near the strip of bottles, suitable to heat the bottle strip from opposite sides;

(d) then, the strip S pass through the closing station 15, where two jaws 15A are provided, heated if necessary, pushed against each other with the open ends of the bottles of the strip S being plastically deformed, thus closing the openings F1 of the bottles;

(e) the strips of closed bottles are ready to be stored or for other processing.

According to the invention, the heating means, allowing to fuse, at least partially, the plastic of the open end of the bottles, are infrared heaters 14A, like, for instance, infrared lamps.

Figure 10 shows, for instance, a linear infrared lamp, like those schematized in figure 3. Panels 14B may be associated to the infrared lamps, reflecting the heating on the side of the lamp opposite to that where there are the bottles, so as to increase the thermal yield (panels of this type, for instance curved panels, are shown in figure 4 on a side of the line; the panels corresponding to the opposite lamps have been omitted, for the sake of simple drawing, but they are intended to be present).

Figure 11 and 12 show two infrared heaters 14 in the form of heating panels, adequately shaped so as to surround the bottles in series along the line.

The infrared heaters may be arranged only on a side of the moving line (i.e. on only one side of the bottles) or on both the sides of the line, or above the line (i.e. above the opening of the bottles).

For instance, in figure 5 bottles are shown in the form of plastic vials (the vials are preferably axially-symmetrical bottles, comprising a base cylindrical body from which a tapered portion extends, ending in said open end that shall be sealed). In this case the infrared heater (in this case a linear infrared lamp) is arranged above the opening 14B. Figure 6 show an example wherein the heaters are arranged on opposite sides of the vials F.

Figure 7 shows an infrared heater so arranged as to surround substantially completely (notwithstanding a small segment) the open end 14B of the bottle (for instance an approximately circular infrared lamp).

It is also possible for the infrared heater to be driven into rotation around the open end 14b of the bottle, so as to heat the end in a homogeneous manner.

It is also possible for the bottle to be driven into rotation around its axis X, so that the end is heated in a homogeneous way. For example, in figure 13 and figure 14 means are shown to drive the bottle into rotation. Figure 13 shows a template 16 for transporting the vial associated with rotating means (not shown) for the rotation around the central axis X. In figure 13 a vial F is shown, rotating around its axis X by means of rotating rollers 17.

In order to close the open end 14B of a vial, instead of two jaws it is possible to use a closing body 18 (see figures 8 and 9), heated if necessary, concave, suitable to be pushed with its concavity facing said open end 14B, against the same end 14B, thus plastically deforming it and closing it (in figure 8, the end of the vial is closed). In the preferred embodiment, wherein the closing body 18 is not heated (the fusing heat is only given by the infrared heaters), it may be cooled, so as to increase the production rate.

In the shown examples, according to preferred embodiments, the bottles preferably have the following dimensions: width comprised between 0.5 cm and 2 cm, depth comprised between 0.5 cm and 2 cm, height comprised between 1 and 10 cm.

It is understood that what illustrated above purely represents possible non-limiting embodiments of the invention, which may vary in forms and arrangements without departing from the scope of the concept on which the invention is based. Any reference numbers in the appended claims are provided for the sole purpose of facilitating the reading thereof in the light of the description before and the accompanying drawings and do not in any way limit the scope of protection of the present invention.