"IMPROVED BLISTER-MAKING MACHINE, CONNECTED METHOD FOR PACKING IN BLISTERS, AND BLISTER PACK THUS OBTAINED"
FIELD OF THE INVENTION
The present invention concerns an improved blister-making machine, more precisely a blister-making machine for packing toxic, toxic-noxious and cancerogenous products and, more generally, products that are dangerous for man, animals or the environment, hereafter referred to generically by the term noxious materials.
The present invention also concerns a connected method for packing noxious materials in blister packs, and the blister pack thus obtained containing noxious materials.
BACKGROUND OF THE INVENTION
Blister-making machines are known, that serve to produce blister packs provided with blisters in which noxious materials as indicated above are introduced and sealed.
Known blister-making machines are of two types, that is, a first type where they are completely contained in controlled chambers, and a second type that is partly enclosed in an insulated chamber.
These strategies are necessary because handling the noxious materials, whether they are packed in capsules, tablets or other, in any case generates powders that are in themselves noxious.
The first type of blister-making machine has the disadvantage that the operators operating inside the controlled chamber have to wear protective clothing such as protective suits. These can be the type that allow autonomy of movement, or the type with continuous blowing of air. The choice of which type of protective suit to use depends on the type of noxious product that is handled by the blister-making machine. This entails considerable costs, long times, encumbrance for the operators, waste of energy, powerful depression systems, complex rooms or premises that in themselves are costly.
The second type of blister-making machine provides that the insulated chamber encloses at least the unit that distributes the noxious material. This known technique generates considerable problems every time the operators have
to intervene on the distribution unit for cleaning, maintenance or for change-of- format of the product processed, or other operations such as replacement.
Document WO-A-02/092439 describes a blister-making machine of the known type.
Purpose of the present invention is to obtain a blister-making machine which is simple to make, is not bulky, which allows to intervene easily and quickly for maintenance operations, cleaning, change-of- format of the product, or other.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
SUMMARY OF THE INVENTION
The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
In accordance with the above purpose, the improved blister-making machine according to the present invention comprises a sealing device to seal a noxious material between a strip provided with blisters (hereafter referred to as blister strip) and a covering or sealing strip to define the blister packs, and an insulated chamber disposed upstream of the sealing device. The insulated chamber is protected toward the inside and kept in a condition of depression using known systems, depending on the type of noxious material that is handled and inserted into the blister packs.
In variant embodiments, the insulated chamber is kept at a depression comprised between 30 Pa and about 100 Pa, also depending on the type and characteristics of the powders that the noxious material processed can generate.
According to the invention, a pre-sealing device is present in the insulated chamber, as well as at least part of the device that delivers and inserts the noxious material to be packed into the blisters present in the blister strip.
The pre-sealing device applies the covering strip on the blister strip, in the blisters where the noxious material is already present, so as to close the blisters made in the blister strip.
However, the application of the covering strip only affects two continuous bands located near the lateral and longitudinal edges of the blister strip to be
covered by the covering strip.
Advantageously, the sealed continuous bands are at the ends of the longitudinal edges, ends which can later be eliminated.
According to a variant of the present invention it may be provided to make pre-sealing bands also at intermediate positions between the two lateral edges of the blister strip.
In this way an element is generated, in practice tubular, at least closed laterally, which does not allow the noxious material to spread outside. The tubular element, in the form of a strip, after exiting from the insulated chamber is sealed by the known sealing device.
According to a variant, the blister strip in proximity to the exit from the insulated chamber is cleaned of any possible powders present on its surface.
Once all the subsequent, normal operations that are made on the now sealed blister strip have been carried out, at least the lateral pre-sealed bands are eliminated and sent where the residual product has to be sent to be destroyed or made inert.
According to a variant, together with the pre-sealing device a cleaning system may be provided which cleans the possible powders on both longitudinal sides from the surfaces of a band equal to or larger than the band that will be formed by the pre-sealing.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:
- fig. 1 is a schematic representation of an improved blister-making machine;
- fig. 2 is a schematic representation from above of the blister-making machine in fig. 1 ;
- fig. 3 shows a system using a gaseous fluid jet to clean the lateral bands before pre-sealing;
- fig. 4 is a schematic representation of the pre-sealing step limited to one side of the blister strip;
- fig. 5 is a representation of a possible mean for cleaning the surface of the pre- sealed blister strip at entrance to and exit from the insulated chamber.
To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings.
DETAILED DESCRIPTION OF ONE FORM OF EMBODIMENT
With reference to the attached drawings, an improved blister-making machine according to the present invention is denoted in its entirety by the reference number 10.
The blister-making machine 10 comprises known devices such as a moldable strip 1 1, a molding machine 12 of blisters 30, a distributor device 16 to distribute the noxious material 33 to be introduced into blisters 30 made in the moldable strip 1 1 to define a blister strip 13, a sealing device 18, a possible pre-sectioner 20 of blister packs, a coding device 21 and a shears 22 that eliminates lateral bands 19, in this case pre-sealed, as will be explained hereafter.
The distributor device 16 is put in an insulated chamber 15 and can be connected, with the appropriate strategies, with the outside in order to feed the noxious material or noxious products 33 to be packed into the blisters 30, made in the molding machine 12 on the moldable strip 11 to define the blister strip 13.
In other embodiments, it may be provided that the blister-making machine 10 also comprises another insulated chamber, also subject to a depression, solely in order to contain the distributor device 16 that sends the noxious material 33 to the insulated chamber 15 only through the distribution pipes, of a known type.
It also comes within the spirit of the invention to provide, inside the insulated chamber 15, suitable nozzles to deliver liquid and/or gaseous fluids, hot or cold, for washing and/or drying. In this embodiment, suitable protected drains are provided.
The insulated chamber 15 has a suction and filter system 24 and a control and adjustment system, that is, depression means 25, to control and adjust the depression to which the insulated chamber 15 is subjected.
The shears 22 can cooperate with a safety container 23 that collects the eliminated bands and that can also be equipped with a suction and filter system 24 identical to the one provided for the insulated chamber 15. The safety container 23 may cooperate with a continuous or discontinuous shearing system for the eliminated bands.
Inside the insulated chamber 15 there is a pre-sealing device 17, fed with the
covering strip 14.
The pre-sealing device 17 has two pairs of opposite wheels 29-129 (figs. 4 and 5), which operate in coordination and each of which seals one of the two lateral bands of the blister strip 13 joined with the covering strip 14 along respective lateral edges 1 19 of the combined blister strip 13 and covering strip 14, obtaining sealed longitudinal and continuous bands 19. A pair or both pairs of opposite wheels 29-129 is subject to pressure toward the other pair of wheels 129-29.
Therefore on the advancing strip thus molded a tubular element is formed, defined by the two longitudinal and continuous sealed bands 19 present on the long edges of the combined blister strip 13 and covering strip 14.
Consequently, any possible powders deposited on the strips are blocked inside the tubular element obtained.
In an alternative solution, not shown, each pair of opposite wheels 29-129 can be replaced by a wheel and a stationary sealing element, for example shaped like a tile or plate, positioned above the strip 13, 15 on which it slides. In another alternative solution, not shown, each pair of opposite wheels 29-129 can be replaced by a fixed guide, located under the strip 13, 14 and on which the strip 13, 14 slides, and a wheel or stationary sealing element, for example shaped like a tile, located above the strip 13, 14.
In the proximity of the exit from the insulated chamber 15 (that is, immediately before or in connection with the exit), possible fluid jets (fig. 5) clean the surfaces of the coupled and pre-sealed strip, rejecting inside the insulated chamber 15 the possible powders that might be present on said surfaces. In the example shown in fig. 5, in cooperation with the exit wall 1 15 of the insulated chamber 15, which exit wall has suitable protective screens, there are cleaning means, in this case nozzles 26-34, which send fluid jets (air, inert or particulate gases) that clean the surfaces and send possible powders inside the insulated chamber 15.
It comes within the spirit of the invention to make suction means for sucking in any possible powders present on said surfaces cooperate with the surfaces of the combined blister strip 13 with noxious material 33 pre-sealed by the covering strip 14.
In the example shown in fig. 3, just before the pre-sealing device, for every
longitudinal side and cooperating with the line 27 that eliminates the sealed continuous band 19, there is a cleaning device 35 that delivers a jet of fluid to clean the surface of the edges 1 19 of possible powder of noxious material deposited there.
It also comes within the spirit of the invention to clean the zones of the blister strip 13 containing the noxious material 33, in which the pre-sealed bands will be made by means of suction means.
Obviously, the entrances and exits of the insulated chamber 15 are structured and organized in a known manner so that there is no danger that possible powders created in the insulated chamber 15 can leak out.
Furthermore, the means that deliver the gaseous fluid 26 and 34 as in fig. 5 can be located inside the insulated chamber 15.
Moreover, the cleaning device that delivers the jet of gaseous fluid 35 (fig. 3) can be replaced by a brush system, fixed or rotating.
It is clear that modifications and/or additions of parts may be made to the blister-making machine, the method for packing in blisters and the blister packs thus obtained as described heretofore, without departing from the field and scope of the present invention.
It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of blister-making machine and method, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.