DE2435037C2 - Method of sterilizing objects - Google Patents

Description

The invention relates to a method for ierilizing objects according to the preamble of claim 1 mentioned genus. Such a method can be used, for example, for sterilization of packaging material, packaging containers and of processing and filling rooms in aseptic working packaging machines.

In a sterilization process that has become known, for example from DE-AS 18 15 538, is used in packaging containers, which are filled with a sterile product, hydrogen peroxide in a mist-like form sprayed onto the inside walls of the container and then blown hot air into the container for rinsing. This known method is expensive because it is proportionate to achieve a sufficient degree of sterility a lot of hydrogen peroxide has to be applied to the inner walls of the container and for quick removal of the sterilant by evaporation hot air is required, for the heating of which special facilities and a high expenditure of energy are necessary.

The invention is based on the object of a method for sterilizing packaging materials and packaging machines to create that come into contact in particular with foodstuffs and luxury foods can be carried out particularly economically and guarantees a high degree of sterility.

The solution to this problem is achieved by the measures cited in the characterizing part of claim 1.

The sterilization process according to the invention has the significant advantage that by preheating with hydrogen stored heat condensate of water vapor and hydrogen peroxide on the Surfaces when flushing with unheated air evaporates quickly and is carried away, so that on the provision devices for heating the purge air can be dispensed with. There is also the advantage that when the surfaces are preheated with steam, the surfaces are heated very evenly so that a very high degree of sterility is achieved in a relatively short time. Furthermore, it turns out as advantageous that by combining the preheating of the surfaces to be sterilized with steam the thermal effect and, through the application of hydrogen peroxide, its chemical effect

ίο work together synergistically, making a very short Treatment duration is achieved.

In addition to the prior art on which the genus of the invention is based, DE-OS 16 67 936 describes a method for sterilizing bottles alternatively with several types of sterilizing agents such as steam, sterilizing gases, e.g. B. ethylene oxide or chlorine dioxide, and liquid sterilizing agent !, z. B. hydrogen peroxide became known. In this known method, the respective sterilizing agent is allowed to flow into the bottles, circulate therein and finally flow out. Limiting the use of ethylene oxide or chlorine dioxide, it is pointed out that the interior of the Raschen ^{should be blown out with a 1} : neutral gas, for example with sterile air, after sterilization. In the known teaching, rinsing is limited to sterilizing agents that have a strong odor, are sometimes toxic and denature foods that contain protein. This also applies to sterilization processes known from DE-OS 19 51 486 and "Wallhäusser: Sterilization - Disinfection (1967), pp. 93,97,98" in which formaldehyde or ethylene oxide is used. Then formaldehyde is mixed with saturated steam, the mixture is passed into a treatment chamber and sucked off again after the sterilization phase. The use of these sterilizing agents in connection with the packaging of food is not without danger, on the one hand during handling by the operating personnel and on the other hand for the consumer if traces remain in the packaging. In particular, ethylene oxide is harmful and explosive. In addition, degassing is necessary after the sterilization process, which is why, in the known sterilization processes, degassing by vacuuming is necessary after the sterilization phase before flushing with sterile air. For this, however, an evacuation device must also be provided.

These disadvantages apply in the same way to those known from DE-OS 14 92 461 and DE-OS 16 42 160 Sterilization processes in which the objects to be sterilized are first treated with ethylene oxide be acted upon with steam.

To see is the use of a combination of several sterilants (US-PS 31 17 832) and the Use of a sterilizing agent at an elevated temperature (DE-AS 17 92 157 and DE-OS 21 45 841) known because of their synergetic effect. With the known However, this method will only have this effect through the use of ethylene oxide or propylene oxide achieved, so with sterilizing agent !, which, as already mentioned above, in the field of packaging technology are extremely questionable.

The features listed in the subclaims show advantageous embodiments of the method according to claim 1. In the embodiment of the invention, in which the hydrogen peroxide with water vapor is fed to the surfaces to be treated, there is the advantage that the hydrogen peroxide is very uniform

3

is distributed moderately on the surfaces, with the introduction into the container or on the inside of the

For the hydrogen peroxide, a single nozzle is sufficient.Cover, a jet of steam is directed by the fact that the loading through This procedure remains the equipment expense holder and lid are thin-walled, they heat up very low. very fast. At the next station, the container

The invention is introduced with reference to exemplary embodiment 5 ter a steam-sterilizing agent mixture len explained in more detail below The sterilizing agent is hydrogen peroxide, which

is sprayed into the steam. Finally, with

Example 1 non-heated, sterile air on another station

the steam remaining in the container, the K *. ndens-

In a packaging machine in which containers made of io water and the remaining sterilizing agent are removed formed, filled and sealed a packaging material web In example 2 can also advantageously

are the corresponding devices for the modifications described in Example 1 to carry out find a turnaround in the individual work processes. Surrounding tunnel or housing in which the packaging material Introduced through a sterilizing lock and the finished packs through a small opening be led out. A sterile atmosphere of sterile air is created in the housing during operation maintained under slight overpressure.

For sterilizing the interior of the housing and the devices contained therein before the start of the packaging process Saturated steam is introduced into the housing through a nozzle. The flowing steam is distributed in the housing, acts on and heats all surfaces in the housing, including those that have already been introduced Part of the packaging web. Part of the amount of steam that does not condense flows through the opening away.

When the surfaces are almost heated to the temperature of the steam, a certain amount of hydrogen peroxide is briefly added to the steam flowing in. Nebulized with the help of sterile compressed air It can also be introduced into the steam line through an injector nozzle in a liquid or gaseous state.

The sterilizing agent is brought to the surfaces to be sterilized in a finely distributed manner with the steam, as a result of which The interaction of the heat and the sterilizing agent results in an intensive disinfection.

Then the steam remaining in the housing, the undecomposed hydrogen peroxide and the condensation water flushed out of the housing with unheated air that has been sterilized by a sterilization filter. As a result of that the treated surfaces are still hot, the remaining condensation evaporates in the cold one supplied Air very quickly, which heats up and the surfaces and parts cool down again. The packaging machine is on it ready for packing.

A modification of this example can be brought about in that hydrogen peroxide is replaced by in the housing arranged nozzles is atomized.

Furthermore, in the example described, the rinsing of the surfaces can be intensified in that after introducing the hydrogen peroxide and prior to purging with air for a specific short period of time steam is still passing through the housing.

B e i s ρ i e 1 2

In a packaging machine encapsulated by a housing are prefabricated containers, for example made of sheet metal, plastic, cardboard, paper or the like. Packing material filled and sealed. Before filling, the containers and, if necessary, separate lids are required for closing, these sterile

Claims (6)

Patent claims: 1. A method of sterilizing the surfaces of objects in which the surfaces are first treated with hydrogen peroxide supplied in finely divided form and then flushed away again with sterile air is, characterized in that the surfaces before the supply of hydrogen peroxide be treated with flowing steam, and that for flushing away the hydrogen peroxide unheated air is used. 2. The method according to claim 1, characterized in that that the hydrogen peroxide is supplied to the surfaces together with water vapor. 3. The method according to claim 2, characterized in that the hydrogen peroxide is the water vapor is admixed by spraying. 4. The method according to claim 2, characterized in that the hydrogen peroxide with sterile Air is mixed with water vapor. 5. The method according to claim 2, characterized in that the hydrogen peroxide prior to admixing is evaporated to water vapor. 6. The method according to any one of claims 1 to 5, characterized in that before flushing away of the hydrogen peroxide is first flushed with steam with unheated air.