JPH04215925A - Method and device to sterilize band material for packaging material - Google Patents

Abstract

PURPOSE: To provide a non-chemical, sterilizing method and a sterilizer for a packaging material strip, wherein highly effective and uniform sterilization can be reliably done. CONSTITUTION: A packaging material strip 1 is pre-washed by brushes 21, 22 rotating in a water bath 3. Thereafter, the packaging material strip 1 is additionally washed by sterile water from nozzles 31, 32, then cleaned by sterile air from other nozzles 33, 34, and finally subjected to irradiation from a UV- irradiator 35.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention relates to a method for sterilizing packaging material strips, in which the packaging material strips are first washed in water, then dried with sterilizing gas and finally exposed to ultraviolet light.
UV) irradiation with a irradiator. The invention furthermore provides a device for carrying out this method, comprising an ultraviolet (U) beam passed in front by the packaging material strip.
V) It relates to a type that is provided with an irradiation source and a wet cleaning device placed in front of the ultraviolet irradiation source.

0002

[Prior Art] For example, European Published Patent No. 142
In a method of the above-mentioned type known from German Patent No. 758, the pre-cleaning of the packaging material strip in a water bath is carried out by ultrasonic waves. In this case, since some of the viable bacteria are first dissociated and removed from the surface of the packaging material strip, the load of viable bacteria on the packaging material strip is reduced during the next step of UV (ultraviolet) irradiation. Therefore, the sterilization rate with such known methods is on average very high. However, experiments have shown that the sterilization of packaging material strips by known methods is often insufficient.

0003

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-chemical sterilization method and sterilization device for packaging material strips, which can ensure highly effective and uniform sterilization. It's about doing.

0004

SUMMARY OF THE INVENTION According to the invention, this object is achieved in a method of the type mentioned at the outset by carrying out a pre-cleaning of the packaging material strip in water by brushing. Furthermore, according to the invention, in a device of the type mentioned at the outset, the wet cleaning device has at least one brush of the roller type, which rotates while rubbing the surface of the packaging material strip. It has been resolved.

[0005]

According to the present invention, the combination of wet cleaning using a brush and subsequent UV irradiation provides a much better effect than pre-cleaning using ultrasonic waves. However, as is clear from experiments, wet cleaning using a brush alone provides a lower cleaning effect than ultrasonic bath cleaning. The superior effects of the method of the invention will only be explained supplementarily below. That is, although ultrasonic cleaning can dissociate particles and microorganisms that are loosely adhered to the surface of the packaging material by cavitation due to the ultrasonic action, it is not possible to dissociate deposits consisting of strongly adhered dust and microorganisms. Moreover, the microorganisms deposited in this manner cannot be detected sufficiently by UV light because they form a shadow. In contrast, the brush cleaning of the present invention dissociates microbial deposits alone, or by crushing these deposits and dust particles, and dissociates them into the water surrounding them and into large pieces of packaging material strips. Can be distributed over the surface. Microorganisms that are finely distributed in this manner can be well detected using UV rays. Therefore, wet cleaning with a brush and UV
In combination with irradiation, a better effect is obtained than pre-cleaning with ultrasound.

Furthermore, according to the invention, after cleaning with a brush, microorganisms are locally and very loosely attached to the surface of the packaging material. This is because microorganisms are dissociated by washing and then washed away. Microorganisms in such a state are then removed by a sharp sterile fountain stream and a sharp sterile air stream. In this way, the sterilization effect is further enhanced.

The device for carrying out the method according to the invention has, in front of the UV radiation source, at least one brush of roller type, which scrubs the surface of the packaging material strip. If the bristle end of this brush is rubbed against the surface of the packaging material strip under slight tension, a very good cleaning effect is obtained. Additionally, such equipment is easy and inexpensive to manufacture and provides a gentle treatment of packaging material strips.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be explained with reference to the illustrated embodiments.

The packaging material strip 1 is continuously drawn off by a storage roller 2 and guided into a tank 12 from above by a deflection roller 11 . In the tank 12, it is guided in a zigzag manner via the lower three deflection rollers 13, 14, 15 and the upper two deflection rollers 16, 17, and then is guided upward by a predetermined length. tank 1 again
It is taken out from 2. And finally, the direction changing roller 18
to a packaging machine (not shown). Further, the tank 12 has a sterilizing water bath 3, and the water surface of the sterilizing water bath 8 is located above the two upper deflection rollers 16, 17. Further, above each of the upper deflection rollers 16, 17, roller-type brushes 21, 22 each having a plurality of bristles 23 protruding in the radial direction are provided.
They are each arranged coaxially and rotatably. In this case, the rotation axis of each brush 21, 22 is the same as that of each direction changing roller 16.
, 17 are spaced approximately 1 mm smaller than the radial length of each bristles 23. This results in
The ends of the bristles 23 come to rub against the packaging material strip 1 guided via the deflection rollers 16, 17, while being slightly taut. Further, the brushes 21 and 22 are rotationally driven in a direction opposite to the direction in which the packaging material strip 1 is conveyed,
And they are arranged below the hoods 25 and 26, respectively. Furthermore, since the lower portion of each brush 21, 22 is immersed in the sterile water bath 3, the downwardly protruding bristles 23 of the brushes 21, 22 are slightly taut as they pass through the deflection rollers 16, 17. contact with the packaging material strip 1 that is being guided. Therefore, when the brushes 21, 22 rotate as the packaging material strip 1 is guided through the sterile water bath 3, the side of the packaging material strip 1 facing the bristles 23 of the brushes 21, 22 will
It is rubbed by these bristles 23. As a result, the submerged packaging material strip 1 is mechanically thoroughly cleaned by the brushes 21, 22. Thereby particles stuck to the surface of the packaging material strip 1 to be rubbed by the brushes 21, 22;
For example, dust or microorganisms or the like are dissociated.

After such a mechanical wet cleaning and after removal from the sterile water bath 3, the packaging material strip 1 is guided through between two nozzles 31, 32. These nozzles 31,
322 cleans both sides of the packaging material strip 1 with a wide sharp jet of sterile water. This removes loose impurity particles on the packaging material strip 1. This packaging material strip 1 is then guided once more through two further nozzles 33, 34. These nozzles 33, 34 spray a sharp jet of sterile compressed air onto both sides of the packaging material strip 1. As a result, the moisture remaining in the packaging material strip 1 is removed and the packaging material strip 1 is dried. Next, this packaging material strip 1 passes in front of the UV irradiator 35 with the surface previously rubbed by the brushes 21 and 22 facing, and is irradiated with UV rays by the UV irradiator 35. This UV irradiator 35 is preferably of type C with an output of 110 mWcm2. The irradiation time is also advantageously 5 seconds. The packaging material strip 1 treated in this way is finally fed to a packaging machine (not shown) and formed into a packaging container.

In the device according to the invention described above, only one side of the packaging material strip 1, ie the inner surface of the packaging container, is processed. However, the other side of the packaging material strip 1 can also be sterilized by means of a suitable device consisting of a brush and a UV irradiator. Furthermore, it may be advantageous if detergents or surface-active media are optionally added to the sterile water bath.

Now, in the experiment, the thickness was 0.6 mm and the width was 21 mm.
A 9 mm polystyrene packaging strip was infected with bacterial microspores. The following table shows the energy density of 16W/20 seconds for processing time.
sterilization effect of packaging material strips using ultrasonic waves in watts per liter of water in the tank and wet sterilization using the brush of the invention at a residual time of packaging material strips in a water bath of 20 seconds. It is a table comparing the sterilization effect of packaging material strips by washing. However, in either case, the next stage of UV irradiation is for 5 seconds.

[0013]

[Table 1]

Further experiments have shown that very good sterilization rates were obtained even with pre-cleaning using only one brush. However, in this case, increasing the residence time of the packaging material strip in the water bath while using a UV radiation source only increases
The sterilization effect is only marginally better compared to the sterilization effect when cleaning with two brushes.

[Brief explanation of the drawing]

1 shows a simple cross-sectional view of the device according to the invention, FIG.

[Explanation of symbols]

1 Packaging material strip 2 Storage roller 3 Sterilized water bath 11 Direction roller 12 Tanks 13, 14, 15, 16, 18 Direction rollers 21, 2
2 Brush 23 Bristle 25, 26 Hood 31, 32, 33, 34 Nozzle 35 UV irradiator

Claims (8)

[Claims] 1. A method for sterilizing a packaging material strip, the packaging material strip being first washed in water, then dried with a sterilizing gas, and finally irradiated with an ultraviolet (UV) irradiator. In the type of packaging material strip (1
) A method for sterilizing packaging material strips, characterized in that the pre-cleaning in water is carried out by brushing. 2. The method as claimed in claim 1, wherein the packaging material strip (1) is brushed by rotating brushes (21, 22). 3. The method according to claim 1, wherein the brushing with the brushes (21, 22) is carried out in a water bath (3). 4. The method as claimed in claim 1, wherein the packaging material strip (1) after brushing and before drying is cleaned with a sharp sterile jet. 5. Apparatus for carrying out the method according to claim 1, comprising: a source of ultraviolet (UV) radiation passed in front of the packaging material strip; In the case where the wet cleaning device is provided with a wet cleaning device arranged in front of the source, the wet cleaning device includes at least one roller-type brush ( 21, 22). Device for sterilizing packaging material strips. 6. Device according to claim 5, characterized in that the bristles (23) of the rotating brushes (21, 22) are rubbed against the packaging material strip (1) under slight tension. 7. The distance between the axis of the rotating brush (21, 22) and the axis of the packaging material strip (1) against which this brush (21, 22) is rubbed is the same as the bristles of the brush (21, 22). 7. The device of claim 6, wherein the radius is approximately 1 mm smaller than the radius of (23). [Claim 8] The packaging material strip (1) has a brush (21
, 22) supported by deflection rollers (16, 17) in the area rubbed by the bristles (23) of the
The device described.