The invention relates to a method and a device for sterilization
an undeformed, cyclically promoted packaging material web, the
subjected to a sterilizing agent by means of an application element,
Irradiation exposed and under sterile conditions of further processing
The sterilization treatment of packaging material webs of suitable material, such as plastic, metal foil or combinations thereof, is well known and in use, so that there is no special printed evidence in this regard. The measures and means for the sterilization of packaging materials ultimately also depending in each case over a certain period of time in a package to be kept sterile, especially intended for consumption contents are varied and range for the packaging material, for example. In individual or combined application of temperature treatments on steam and UV light exposure to the use of hydrogen peroxide in liquid or vaporized or misted form, for example. According to DE 27 03 524
Since more and more stringent requirements are made with regard to still acceptable bacterial load on foodstuffs, the tendency in practice is to a greater extent in particular a combined use of applied H 2
solution as sterilizing agent with subsequent germicidal irradiation, although peroxide is toxic in itself , See, for example, the EP 0 919 246 B1
, which, in the case of applied UV irradiation, depends on the object of the DE 42 09 838
only un thereby distinguishes that instead of hot water, a peroxide solution is used, in both cases before the irradiation plentifully applied by immersion water or sterilizing agent must be scraped off by air jets in a sense to the one, the subsequent germicidal irradiation good effect and, when using peroxide solution, to ensure that no or only within permissible limits permissible residues of peroxide are present in the filled packaging.
The sterilizing effect on the one hand of peroxide and on the other hand UV irradiation is known since at least the beginning of the eighties of the last century according to US-PS 4,366,125, in which case the UV irradiation takes place before the drying of the packaging material web and. the previous Sterilmittelauftrag in a sense untargeted in a mist application chamber, which is directed with its web-side open cross-section against the packaging material web. Incidentally, in this sterilizing apparatus, the packaging material web to be sterilized is treated in a continuous pass, that is, uncalibrated in an H 2 O 2 mist chamber and rolled up again after UV irradiation and subsequent drying in a collecting chamber to be kept sterile, from which the sterile roll must be removed. in order to be able to further process them, for example, on a packaging machine under sterile conditions. As the sterility of the sterile roll during transfer and further processing on eg. A packaging machine is taken into account, it must remain an open question.
With regard to the fact that to effect a subsequent UV irradiation, the applied H 2
O 2 should be present
only in the smallest possible amount on the packaging material, this is on the already mentioned above EP 0919246
referred, therefore, mainly with the removal of a continuous bath or by spraying excess, apparently on the principle Much brings much, the continuously promoted packaging material web applied H 2
solution deals to the subsequent UV irradiation as optimal as possible to the effect kom and, at contemplated concentrations of 20 to 40% sterilant solutions, to ensure that as little toxic H 2
as possible is introduced into the packages. For the removal of Sterilmittelüberschusses is a special, in the EP 0919246
so-called acceptance device provided, which effectively represents a chamber-like hot air knife with which the excess of sterilant on the chamber continuously passing through the packaging material web is blown off and discharged from the chamber.
Apart from the use of basically aqueous H 2
solutions for sterilization purposes in the field of use of interest for the purpose of certain filling contents, one has, of course, a free hand with regard to their concentration approaches, ie taking into account the abovementioned EP 0 919 246
and here to be mentioned in addition US 4,289,728
In general, solution levels of 0.01 to 50% are contemplated in the art, with the question of the sterile agent lot remaining open and, on the other hand. regarding the mentioned EP 0 919 246
in this regard, as mentioned above, can only be seen to apply the sterilizing agent by bath run, then the inevitable Sterilmittelüberschuß by air knife. to remove by blowing off and in the US 4,289,728
the question of the quantity order or the layer thickness is left open at all.
The invention has for its object to provide not only for a more economical consumption of the sterilant solution itself, but equally for the lowest possible proportion of toxic to itself H 2 O 2 in the sterilant solution and this associated with the proviso, from the outset as possible to achieve thin order of the sterilant solution, and that, which will be explained in more detail, in particular with regard to the special case of sterilization of interest not only an undeformed, but also promoted in the step cycle packaging material web.
Task is with regard to the procedure by the in the license plate
of claim 1 cited
Characteristics or method steps solved. In this regard, advantageous developments
arise after the closer
to be explained
In spite of
on the one hand, from the outset, to a certain extent extremely thin, that is,
in the lower μ range
(<100 μ) lying
Sterilizing agent layer leading
area-related quantity order
and on the other hand, one of them almost in contradiction (low concentration
to the idea
to balance this by putting more in quantity)
Sterilmittelkonzentration in the specified order results, as
Trials have shown, surprisingly
one for too
especially the food sector absolutely satisfactory and sufficient
Germ kill rate.
In this regard,
can only be suspected that through
Sterilization agent on the one hand existing germs for the subsequent UV irradiation
better accessible per se
are and that on the other hand
the very thin applied
Layer, measured by the average dimensions of germs
in the order of magnitude
from about 1 to 10 μ, sufficient
thick to capture the germs.
This is advantageous on the one hand with a correspondingly economical consumption of H 2 O 2 , and on the other hand, the wafer-thin applied to the packaging material layer layer of Sterilittelellösung remain on this, since the low H 2 O 2 concentration and also. the small amount remain within the permissible limits of what may remain in the filled packaging or may still be present. Moreover, if this should require special requirements, there is nothing to prevent the wafer-thin layer from drying on the web before the subsequent UV irradiation.
A surplus elimination
of too much or too much applied sterilant
So is not in the process of the invention
By deep-drawing and ultimately also tubular bag packaging machines, the packaging material webs are conveyed in a step-cycle, ie, a machine running and an upstream Sterilisationsmittel-Beaufschlagungszone continuous packaging material web this would also happen in step-clock, but what, as readily imaginable and so far known, so far apparently unnoticed, contrary to the order of a continuous uniformly uniformly thin H 2 O 2 layer, as it inevitably occurs at clocked Bahnstillstand between the conveying acts in permanent permanent Sterilmittelaufsprühung on the packaging material to areas reinforced Sterilmittelauftrages. In this regard, the inventive method has proved to be particularly advantageous because even then thin yet thin Sterilisationsmittel overlap strips on the clocked continuous packaging material result due to the extremely thin sterilizing agent order, which, as has been shown, on the one hand no much higher burden represent the packaging with H 2 O 2 . and on the other hand in an approximately subsequent Trockrockphase be detected and dried with ease. Avoidable would be those with clocked promotion of the packaging material web resulting overlapping areas only by interrupting the Sterilmittelzufuhr clocked accordingly, but with respect to the anyway low applied sterile agent quantities, if at all, would be extremely difficult to implement.
the extremely thin,
homogeneous layer application (comparable with a misted window)
to reach the packaging material web, it has proven to be expedient
not for one
Order to worry about how he is passing through the packaging material web
by a dip
or even when passing through a mist or vapor deposition chamber,
but that over
uniformly distributed sterilizing agent throughout the entire width of the packaging material web
in Strichmanier nationwide
and to its implementation
required sterilization device are described below
the drawing of exemplary embodiments explained in more detail.
1 highly schematic side view of a thermoforming packaging machine with integrated sterilization device;
2 also very schematically the sterilization device;
3 in plan view, a piece of the packaging material web to be sterilized in Taktschrittteilung and
4 one of the 3 Corresponding representation of the packaging material web with modified spray direction.
is on the here in particular interest step-step promotion
the packaging material web is referenced by a thermoforming machine, although
the process also readily in a continuous promotion
the packaging material web is applicable.
The sterilization device SE for carrying out the method on packaging machines, with which therefore a packaging material web PB in the step-stroke of a stock roll holder 1 deducted and by their in a sterile tunnel 2 located processing stations 3 is still funded by an applicator unit 4 with sterilant supply 5 , and an irradiation station 7 In the special case, as mentioned above, a drying station 6 can be upstream.
The packaging material web PB to be sterilized is in step-by-step from the stock roll holder 1 pulled off and through in a sterile tunnel 2 located processing stations 3 (Form (FS), filling (F) and closing (SS)) of the example. FFS packaging machine shown promoted.
The case of self-interest sterilization device SE is in the illustrated Ausführungsbei game according to 1 between the stock roll holder 1 and the forming station FS, irrespective of whether the sterilizing device is a step-by-step adjusted feeding device for the packaging machine or a machine part integrated in the packaging machine from the outset.
In order to carry out the method according to the invention, is for the in 1 a total of dash-dotted lines illustrated sterilization SE total significantly that the sterilization device between the packaging material supply roll holder 1 and the forming station FS, such as thermoforming station, tube forming station or the like. the packaging machine is arranged; that further before the post-treatment station 7 arranged application unit 4 from one of the width B of the packaging material web PB or at least one clock step length L corresponding, connected to a Sterilmittelverdampfungs- or misting chamber K and directed against the packaging material web PB, at least one broad jet effecting application element 8th is formed and that finally in the sterilant supply 5 of the applicator 4 a sterilant flow regulator 9 is arranged.
What is the mission element 8th is concerned, this is in the form of a slot die 8th' formed, which may be composed for the purpose of uniform distribution of the sterilizing agent in the nozzle of a plurality of smaller slot dies or with inner small distribution webs 8th'' is provided. With regard to the small amount of sterile medium solution to be differentially applied, the opening slit or the slits are only a fine outlet gap, for example of the order of only 0.3 mm and below.
The adjustable depending on the conveying speed of the packaging material PB sterilizer flow regulator 9 ensures that as far as possible exactly the amount of sterilant discharged and applied to the packaging material web, which is required for the formation of a thin layer of sterile medium solution in the aforementioned aforementioned order of magnitude, to the actual application unit 4 Of course, there are still the supply means for the coming to use, dilute H 2 O 2 solution and a transport medium, for which one of the evaporation or misting chamber K, for example. Pressure-operated injector 11 for combining the sterile medium solution and a gaseous carrier medium, for example sterile air, is connected upstream.
Sterile agent supply to the wide slit nozzle takes place continuously during the
Run the whole length
one rolled up
stationary packaging material web, which due to clocked promotion of the packaging material due
the train stops
to the aforementioned
narrow overlap strips
Regarding the treatment station following the sterile agent application station 7 is concerned, this is with one or more UV lamps 7 ' stocked. This treatment station 7 can gegf. and, as indicated by dashed lines, from the sterile tunnel 2 the processing stations 3 be covered with the relevant FFS machine, so that the last phase of sterilization (final germ killing) already takes place in sterile atmosphere.
In order to comply with the advantageous proviso, namely exposing the packaging material web PB to a germ-attacking pre-irradiation prior to the application of sterilizing agent, it is possible to place between the supply-roll holder 1 and the sterilization device SE an at least germ-damaging Vorbestrahlungsstation (not shown) may be arranged, for which also a suitable UV emitter comes into consideration. A pretreated packaging material web PB thus advantageously gets under with its germs, which to some extent have already been damaged sublethally the effect of the then thinnest layer and thus sparingly sprayed sterilizing agent.
In the already mentioned 3 is a packaging material web section with dash-dot conveyor clock step division TS is provided, with sections I-IV, each having a clock step length L. It can be left undecided whether in practice between the sections I to IV are still one or more sections. All treatments on the sections I to IV of the still undeformed packaging material web PB occur simultaneously, wherein the section I is exposed in this embodiment, a germ-attacking pretreatment by UV irradiation. A section II pretreated in this way is transported successively in the direction of arrow P by means of the slot die 8th in the sense of the thin lines DL from the leading dot-dash line to the subsequent dash-dotted line LI volume controlled with sterilant in the thinnest layer coverage and runs in a special case, while becoming Section III, under the (if available) heat radiator 6 and then passes under the treatment station dried 7 in which the final germ killing is done by UV light. Apart from the section II with its Sterilmittelauftrag can for irradiation and gegf. Also drying treatments also several lengths L be detected. The several mentioned above, right behind the nozzle 8th Incidentally, resulting overlapping areas UB are in 3 indicated by cross-hatching.
The occupation of the sections with the sterilizing agent solution does not necessarily have to be carried out as described in the direction of extent or conveying direction of the packaging material web, which is preferred, however, since in the case of a stationarily arranged slot die 8th the conveying movement of the web is utilized.
But it is also possible, with appropriate width design of the task item 8th to arrange this to the packaging material web back and forth transversely adjustable and this at each standstill (see 4 ) of the railway over the relevant section. The spraying process would also be uninterrupted in both the outward and the return adjustment.
Incidentally, could be in such, somewhat more expensive equipment-demanding embodiment, since the Auftragseleelement 8th has to be moved clock-adapted, avoid overlap strip advantageous at all, if on the one hand, the width B of the Auftragselememntes 8th exactly on a cycle step length L and the transverse movement on the downtime of the packaging material web would be parked.
Apart from that, in such an embodiment also the advantageous possibility, the travel of the applicator element 8th for its back and forth movement to be measured so that both edges R of the packaging material, as shown, are slightly run over, so that the maintained thereby wide beam is not used, ie, in the waiting position for the respective sequence adjustment the edges can not burden with sterilizing agent. Non-solubilizing sterilant solution can be collected and discharged in collectors.
Such an application across the packaging material web or conveying direction would also be possible with the web moved in the step cycle, with a coating surface oriented diagonally to the conveying direction. However, this would have the task element 8th be reset with interrupted sterile agent supply and standstill of the web, as would otherwise result from the sterilant unoccupied, triangular track surfaces. So this could also be considered, if you want to operate the mentioned greater equipment complexity and also a greater control effort.