DE102024103567A1 - Method and device for sterilizing containers - Google Patents

Abstract

The present invention relates to a method for forming preforms (1) made of a thermoplastic material into containers (2), in which a preform (1) is guided along a transport path through sections of a forming device, the method comprising the following steps: applying a sterilizing fluid to an outer surface of a preform (1) and introducing a sterilizing fluid into an interior (1) of the preform (1) before heating the preform (1) in a heating device, subsequently irradiating only the outer region of the preform (1) with a UV radiation source (101, 101-1, 101-2, 101-3), preferably a UV-C radiation source, to activate the sterilizing fluid on the outer surface of the preform (1), such that the sterilizing fluid on the outer surface is substantially evaporated before heating the preform (1) in the heating device, and subsequently heating the The preform (1) is heated to a forming temperature in the heating device, wherein the heating activates the sterilizing fluid inside the preform. The invention also relates to a corresponding device.

Description

The invention relates to a method and a device for forming preforms made of a thermoplastic material into containers, in which a preform is guided along a transport path through sections of a forming device. In particular, the present invention relates to a method and a device for sterilizing preforms or containers while the preform is guided through certain sections of the forming device.

The production of containers by blow molding from preforms made of a thermoplastic material, for example, from PET (polyethylene terephthalate) preforms, is known. The preforms are fed to various processing stations within a blow molding machine, also referred to here as a device for forming preforms. Typically, a blow molding machine has a heating device for tempering or thermally conditioning the preforms, as well as a blow molding device with at least one blow molding station, in which the previously temperature-conditioned preform is expanded into a container.

Possibilities for tempering the preforms are, for example, in the DE 23 52 926 A1 explained. Tempering or thermal conditioning means heating the preform to a temperature suitable for forming and, if necessary, imprinting a temperature profile on the preform in the longitudinal and/or circumferential directions.

The expansion into the finished container is carried out, for example, with the aid of a pressurized gas, in particular compressed air, as a pressure medium, which is introduced into the preform to be expanded at a molding pressure. The process for such an expansion of the preform is described in the DE 43 40 291 A1 The basic structure of a blow molding station is explained in DE 42 12 583 A1 described. According to a typical further processing method, the containers produced by blow molding are fed to a downstream filling device and filled there with the intended product or filling material. However, it is also possible to produce containers from preforms and simultaneously fill them with a filling material which is supplied as a hydraulic pressure medium for expanding the preform or for shaping the container with a forming and filling pressure. As a result, the respective preform is formed into the container simultaneously with the filling. In expert circles, such methods and devices for simultaneously forming and filling preforms into containers are known under the names "FormFill" or "LiquiForm". The present invention can be advantageously applied to both of the aforementioned forming methods and both types of devices for forming preforms.

Sterilization (also known as sterilization) is understood here to mean a germicidal treatment, for example, using chemical sterilizing fluids. The present disclosure should be viewed from the perspective that, for example, germ-sensitive beverages must be filled under aseptic or sterile conditions in order to achieve the desired shelf life. This requires, for example, that the containers into which the beverages are filled meet these sterile conditions, i.e., are largely germ-free at least on the surfaces that come into contact with the contents. For this purpose, finished containers can be sterilized before filling, or preforms before they are converted into containers, thereby subsequently preventing recontamination. In this way, both the preforms and later the containers produced from them can be sterilized. Sterilizing the preform has the advantage over sterilizing the container produced from it that the surface to be sterilized is much smaller, so that the amount of sterilizing fluid required can be lower.

Typically, after the blow molding process, a rinsing with a sterile rinsing fluid is provided to remove traces of the sterilizing fluid from the finished container. This is the case, for example, in the WO2014/139624A1 The blow molding process itself already leads to a rinsing effect, because the blow gas used and the venting of the blow gas used contribute to the removal of the sterilizing fluid, if it is still contained in the preform before forming. A sterilizing fluid, such as hydrogen peroxide, can also decompose and is therefore no longer contained in the preform or container.

From the DE 10 2014 010 283 A1 For example, it is also known to rinse a preform with a sterilizing fluid while the preform is already in the forming station. It is also known to sterilize a preform before it reaches the forming station ( WO 2010/020530 A1 ), e.g. on the way between the heating device and the forming station, or e.g. before the preform enters the heating device of a blow molding machine, or e.g. before a preform enters a blow molding machine, e.g. in the area of a feed rail for the preforms. From the EP 2 588 295 A1 It is also known to sterilize a preform within the heating device.

A well-known procedure for sterilizing preforms, for example, is to dose hydrogen peroxide (H ₂ O ₂ ) into the preform, heat the preform together with the dosed hydrogen peroxide in the heating device, and then blow mold a finished container. In this process, the majority of the hydrogen peroxide used decomposes into oxygen and water. It is also known to add hydrogen peroxide between the heating device and the forming device. Upon decomposition to ambient pressure, the finished container is rinsed with 25 to 30 times the bottle volume, thus reducing any remaining hydrogen peroxide to a tolerable level.

The aforementioned methods and devices all have their own specific disadvantages and are sometimes complex and costly. The present invention aims to provide an efficient and safe method and device that, in particular, enables sterilization of the outer surface of the preform.

The present disclosure provides a method for forming preforms made of a thermoplastic material into containers. In this method, a preform is guided along a transport path through sections of a forming device. A sterilizing fluid is first applied to an outer surface of a preform. The sterilizing fluid can also be introduced into an interior of the preform. The application and introduction of the sterilizing fluid both occur before the preform is heated in a heating device. After the sterilizing fluid has been applied to the outer surface of the preform, only the outer surface is irradiated with UV radiation from one or more UV lamps, preferably UV-C lamps, in order to activate the sterilizing fluid on the outer surface of the preform. This means that irradiation only occurs on the outer surface, and due to the absorption properties of the preform material, this radiation does not penetrate into the interior and therefore does not reach the sterilizing fluid in the interior of the preform. Irradiation with UV radiation or UV-C radiation occurs in such a way that the sterilizing fluid on the outer surface decomposes essentially according to the reaction equation before the preform is heated in the heating device, i.e., before it reaches the heating section with the heating devices in the heating device. Upon entering the heating section of the heating device, the outer surface of the preform is largely free of sterilizing fluid, and thus no significant sterilizing fluid residues are introduced into the heating section. The preform is then heated to a forming temperature in the heating section(s) within the heating device, with the heating activating the sterilizing fluid inside the preform. The sterilizing fluid contained inside the preform is less of a concern because the preforms are generally guided through the heating device by means of transport mandrels that clamp into the mouth area of the preform, so that the preforms are at least partially closed in the mouth area and sterilizing fluid is prevented from escaping. The transport mandrels offer the possibility of sealing the preform interior from the surrounding heating device. In the described methods and devices, a transport mandrel is therefore advantageously used for transport through the heating device. Preferably, the entire outer surface of the preform is irradiated with UV-C radiation. The above method makes it possible to sterilize the preform on the outside before heating it in the heating device and also to remove any sterilizing fluid from the outside. This reduces or prevents the introduction of sterilizing fluid into the heating device.

The sterilizing fluid is advantageously supplied to the application device in vapor or aerosol form. The preform is advantageously at a temperature that is at or below the condensation temperature of the vapor or aerosol sterilizing fluid. In this way, the sterilizing fluid condenses on the outer and inner surfaces of the preform. The vapor or aerosol supply (through a suitable arrangement of discharge nozzles and a suitable amount of vapor/aerosol) is carried out in such a way that a sufficiently complete condensation film forms on the inside and outside of the preform. This ensures reliable coverage of the surfaces with sterilizing fluid, resulting in full-surface sterilization.

When irradiating with ultraviolet radiation, the preform is advantageously rotated around its longitudinal axis relative to the UV radiation source using a transport device. The advantage is that this avoids areas that receive less radiation than others. Alternatively, the most homogeneous illumination possible would be required across the entire circumference (and, of course, across the entire height) of the preform. If the preform is rotated around its longitudinal axis relative to the UV radiation sources, this is not necessary. Due to the rotation of the preform, it may also be sufficient to irradiate the preform from only one side.

According to a first alternative, the outer side of the preform may not be used at all for gripping (engaging) by the transport devices. Instead, the gripping or engaging of the preform may take place inside a mouth area of the preform, as is known for transport mandrels.

According to a second alternative, the engagement area on the preform can be variable. The UV radiation sources (UV-C lamps) can be arranged, for example, along a circumference, in particular a partial circumference, of at least two transfer devices, in particular two transfer wheels, namely a first and a second transfer wheel. In this embodiment, the preform completes at least one partial revolution (or partial section) during irradiation on each transfer device or transfer wheel. This arrangement enables a practical arrangement of the UV radiation sources only on one side of the transport path and following the curved circulation path of the preform, so that a constant distance is maintained. Furthermore, the engagement area is advantageously changed between the first partial revolution on the first transfer wheel and the second partial revolution on the second transfer wheel, such that the first transfer wheel releases the preform and the second transfer wheel grasps it. The transfer wheels can advantageously have suitable grippers for this purpose. This ensures that areas covered or shaded by the grippers during the first partial cycle are exposed during the second partial cycle on the second transfer wheel, and vice versa. As a result, all areas of the preform are freely accessible to the UV radiation from the radiation sources, at least temporarily.

The preform can complete a partial revolution around the first transfer wheel, being held, for example, above one of its neck rings at a first gripping area. It is then transferred to a subsequent transfer wheel, where it makes another partial revolution, being held, for example, below the neck ring at a second gripping area. Furthermore, this design makes it possible to arrange the UV lamps on only one side of the transport path. By changing the gripping area, the preform is irradiated from a first side during the first partial revolution and from the opposite side during the second partial revolution. This corresponds to a 180° rotation during the transfer.

The UV lamps can be arranged, for example, in a meandering pattern along the transport path. The arrangement of the UV lamps can, in particular, follow the circulation path (one partial circulation each) of the first and second transfer wheels. The advantage is that this extends the path and thus the exposure time within which the UV radiation acts, thus improving the overall sterilization result. This configuration can also reduce the amount of sterilizing agent or the concentration of the sterilizing agent. Furthermore, the length of the transport path during irradiation with UV-C radiation can be selected such that the desired almost complete evaporation (decomposition) of the sterilizing fluid applied to the outer surface has occurred by the time it enters the heating device.

UV lamps can also be advantageously arranged on both sides of the preforms. This allows, for example, the irradiation duration and/or irradiation intensity to be reduced.

According to a further embodiment, UV lamps can be arranged within the heating device, advantageously before the start of the heating section. If the preforms are transported on transport mandrels within the heating device, the preforms can be rotated around their own longitudinal axis relative to the UV-C lamps by means of the transport mandrels while they are moved past the UV-C lamps. It is further advantageous if the transport mandrels only engage the preforms in a clamping manner. Then, the preform is not covered or shaded on its outer surface, which improves the effect and coverage by the UV-C radiation.

Advantageously, the irradiation with UV radiation or UV-C radiation can be carried out in at least three zones that are arranged vertically one above the other. Accordingly, at least one radiator can be directed at a mouth section of the preform, at least one radiator can be directed at a dome of the preform, and at least one radiator can be directed at a shank of the preform. If at least this three-way division is achieved, "shadows" are advantageously avoided. For example, the support ring or neck ring of the preform could cast such a shadow.

The individual radiators can be precisely adjusted in their distance from the preforms, e.g., to adapt to changing preform geometries. When using longer preforms, for example, the radiation source for the preform's crown could be relocated. This is a further advantage of the above-described division into three or more zones.

The majority of UV radiation sources or UV lamps can be arranged in or on a common support. The decisive factor is the arrangement of the UV radiation sources or UV lamps and their orientation to the specified areas.

The UV lamps can advantageously be shielded. Shielding of the UV radiation can be achieved by providing a shielding enclosure that extends at least along the region of the transport path in which the UV lamps are arranged.

The enclosure can also be used to prevent volatile sterilizing fluid from escaping into the environment. The enclosure can provide an extraction zone for the sterilizing fluid, extending at least from the sterilizing fluid supply device to the end of the UV irradiation. Within this extraction zone, both air and volatile sterilizing fluid can be extracted from the enclosure, and preferably sterile air can be actively or passively supplied to compensate for the extracted air.

The present disclosure also provides an apparatus for forming preforms made of a thermoplastic material into containers. The preform is guided downstream within the forming apparatus along a transport path by means of at least one transport device. The apparatus comprises, along the transport path in the downstream direction, a feed device for feeding a preform into the forming apparatus, an application device for applying a sterilizing fluid to an outer surface of the preform and for introducing the sterilizing fluid into the interior of the preform, an irradiation device with one or more UV radiation sources for irradiating the outer surface of the preform with ultraviolet radiation, and a heating device with heating devices along a heating section for heating the preform to a forming temperature. Due to the preform material, the UV radiation does not penetrate into the interior of the preform. The device for applying sterilizing fluid, the irradiation device and the heating device are configured and coordinated with one another in such a way that in the irradiation device the sterilizing fluid on the outer surface is substantially evaporated (or decomposed) before the preform is heated in a heating section of the heating device, and during the subsequent heating of the preform to a forming temperature in the heating device, the sterilizing fluid is applied inside the preform.

The radiation source can advantageously be designed in multiple parts, in particular three parts. One or more first radiation sources (UV-C emitters) can be directed at the mouth section, one or more second radiation sources (UV-C emitters) at the shaft, and one or more radiation sources (UV-C emitters) at the tip of a preform. At least one radiation source, advantageously several or all radiation sources, can be adjustable with respect to their distance from the preform, in particular with respect to their distance from a tip of the preform. This enables adaptation to different preform geometries or preform shapes.

The transport device used to move the preform through the irradiation device is advantageously configured so that the preform rotates at least partially around its longitudinal axis relative to the radiation sources (UV-C lamps) while passing through the irradiation device. This allows irradiation to occur from only one side.

The device advantageously comprises a first and a second transfer wheel, wherein the irradiation device is arranged along a first partial circumference of the first transfer wheel and a second partial circumference of a second transfer wheel. Advantageously, the UV lamps are thus arranged along a circumference, in particular a partial circumference, of at least two transfer devices, in particular transfer wheels, namely a first and a second transfer wheel, wherein the preform completes at least one partial revolution on each transfer wheel during irradiation.

Advantageously, the first transfer device (first transfer wheel) has first grippers and the second transfer device (second transfer wheel) has second grippers, which are configured to engage different areas of the preform. Thus, between the first partial revolution on the first transfer wheel and the second partial revolution on the second transfer wheel, a re-gripping takes place such that the first transfer wheel releases the preform and the second transfer wheel grasps it. This ensures that areas that are covered or shaded by the grippers during the first partial revolution are exposed during the second partial revolution on the second transfer wheel, and vice versa. The preform can complete a partial revolution around the first transfer wheel and is held, for example, above one (its) neck ring. It is then transferred to a subsequent transfer wheel and makes another partial revolution there, where the preform is held, for example, below the neck ring.

The UV lamps can be arranged in a meandering pattern, following the circulation path of the first and second transfer wheels. This extends the path of the UV radiation, thus improving the overall exposure time and thus the sterilization result. This design also allows the amount of sterilizing agent or the concentration of the sterilizing agent to be reduced.

In another embodiment, the UV lamps can be arranged on both sides of the preforms. This can shorten the travel distance.

In one embodiment, however, UV lamps or UV-C lamps can be arranged within the heating device upstream of the heating section, i.e., upstream of the preform heating. Advantageously, the preforms are moved past the UV-C lamps on transport mandrels and further advantageously rotated around their longitudinal axes by means of the transport mandrels. The transport mandrels are advantageously designed to engage the preforms exclusively in a clamping manner. Furthermore, the UV lamps or UV-C lamps can be arranged within the heating device on both sides along the preform transport path through the heating device.

The total exposure time of the UV radiation, possibly during the first and second partial cycles, can be in the order of magnitude of less than 5 seconds, preferably in the range of 1 to 2 seconds. Furthermore, the irradiation duration or exposure time can also advantageously be in the range of 0.5 to 1 second.

Ultraviolet radiation, or UV for short, UV radiation, or UV light, is electromagnetic radiation in the optical frequency range (light) with shorter wavelengths than the light visible to humans. A distinction is generally made between three ranges of UV radiation: UV-A in the range from 380 nm to 315 nm, UV-B in the range from 315 nm to 280 nm, and UV-C in the range from 280 to 100 nm. In the context of the present disclosure, UV radiation is selected to be particularly suitable for the forced decomposition _{of H2O2} into ^HO radicals. For this purpose, a wavelength range of 280 nm to 200 nm is advantageously selected for the UV lamps. This is particularly advantageous because ozone forms below 200 nm, which must be extracted if the concentration is too high. This preferably involves UV-C radiation because it is particularly suitable for accelerating or forcing the decomposition of _H2O2 into ^HO radicals. However, somewhat longer wavelength ranges of UV radiation can also be considered, although their effect may then be correspondingly less. According to the present disclosure, it has been recognized, among other things, that UV radiation in the ₂₅₄ nm range is not only suitable for directly killing germs, but is also particularly advantageous for activating sterilizing fluids, such as _H2O2 (hydrogen _peroxide ). The present disclosure utilizes this finding, among other things.

Advantageously, the radiation source can be configured in at least three parts and be arranged such that at least one radiator is directed toward a mouth section of the preform, at least one radiator is directed toward a crest of the preform, and at least one radiator is directed toward a shaft of the preform. This way, shadowing can be avoided.

Further advantageously, the UV emitters can be arranged at a variable distance with respect to a dome and/or a mouth region and/or a shaft of the preform.

The irradiation device may comprise a housing. The housing may be designed as a tunnel, and the housing may be configured to shield the ultraviolet radiation from the radiation sources in a direction away from the preform.

The enclosure may include a suction device for the sterilizing fluid. The suction device for the sterilizing fluid may be located outside the enclosure. In this respect, the enclosure may be configured to keep the area enclosed by the enclosure free of volatile sterilizing fluid, preventing it from escaping to the outside.

In addition, the enclosure can be connected to a sterile air source configured for the supply or pressurization of sterile air. "Supply" is understood to be passive, meaning that sterile air flows in due to the extraction by the aforementioned extraction device to fill the space created. "Pressurization" is an active pumping of excess pressure toward the enclosure.

• 1 eine schematische Darstellung einer Vorrichtung zum Behandeln von Behältern unter Sterilbedingungen am Beispiel einer Behandlungsvorrichtung zur Herstellung von fertigen Behältern aus Vorformlingen und
• 2 eine vereinfachte schematische Darstellung eines Ausschnitts aus 1,
• 3A,3B jeweils eine vereinfachte schematische seitliche Darstellung eines Vorformlings beim Durchlaufen der Bestrahlungsvorrichtung und
• 4 eine vereinfachte schematische Darstellung eines Ausführungsbeispiels für eine weitere Möglichkeit der UV-Bestrahlung der Vorformlinge.

The disclosure is explained in more detail below using preferred embodiments and the accompanying figures. The drawings are not necessarily to scale. In the figures, identical or essentially functionally identical or similar elements are usually designated by the same reference numerals. They show:

• 1 a schematic representation of a device for treating containers under sterile conditions using the example of a treatment device for producing finished containers from preforms and
• 2 a simplified schematic representation of a section of 1 ,
• 3A , 3B each a simplified schematic side view of a preform when passing through the irradiation device and
• 4 a simplified schematic representation of an embodiment of another possibility for UV irradiation of the preforms.

In the presentation in 1 1 shows a schematic representation of a device for forming preforms 1 or containers 2. Here, in a specific example, a device for producing containers 2 from thermally conditioned preforms 1. The device comprises a blow molding device 30, which in the embodiment shown here is a blow molding device 30 of rotating design with a forming wheel 32 and with several forming stations 31 arranged circumferentially thereon for forming the preforms 1 into containers 2. In the present exemplary embodiment, this can be a blow molding device 30 that forms the containers 2 from the preforms 1 using compressed air, or a blow molding device 30 that forms the containers 2 by introducing a liquid filling material under pressure, which is supplied as a hydraulic pressure medium for expanding the preform 1 and/or for forming the container 2.

The preforms 1 and containers 2 are transported downstream along a transport path in the following manner. Via a feed 40a, e.g., designed as a feed rail or as an air conveyor, the preforms 1 are transferred to a separating wheel 40, which rotates as indicated by arrow 400, driven by a drive (not shown). The preforms 1 are transferred by means of the separating wheel 40 to a heating device 50, which has heating devices 51 along a heating section for thermally conditioning the preforms 1. The preforms 1 are guided in the direction of rotation (transport direction) indicated by arrow 500 along the heating devices 51 or along the corresponding heating sections and then transferred to the rotationally driven transfer wheel 60, which rotates in the direction of arrow 600. From the transfer wheel 60, the preforms 1 are transferred to the blow molding device 30. Finished containers 2 are formed from the preforms 1 by means of the forming stations 31. After the finished containers 2 have been formed from the preforms 1, they are transferred to an output wheel 70, which rotates in the direction of arrow 700. The containers 2 are then transported away by means of a removal device 70a. The containers 2 can be forwarded here, for example, via further transport devices (not shown) to a device for filling the containers 2. Transporting away here therefore generally includes forwarding to the next treatment, which may consist of filling, closing, inspection, or other steps.

The preforms 1 and containers 2 can be held during transport and, if necessary, during individual treatment steps by means of transport mandrels or grippers. In a known manner (not shown), the transport of the preforms 1 through the heating device 50 can advantageously be carried out by a mandrel chain with transport mandrels connected to form an endless chain. The structure of the heating device 50 is generally known and therefore will not be described in detail here.

For the continuous conveyance of the preforms 1 or the containers 2 along a transport path through the entire device of the 1 The rotational movements of the wheels 40, 60, 70, the blowing device 30, and the heating device 50 are coordinated with one another, e.g., by synchronization and/or a common drive. The transport path of the preforms 1 or the containers 2 is defined by the transport path along a partial circumference of the transfer wheels 40, 60, 70, along a partial circumference of the blowing device 30, and along a partial circulation area of the mandrel chain. 1 The illustrated sequence of the spaced-apart preforms 1 and containers 2, starting from the separating wheel 40, via the heating device 50, then via the transfer wheel 60, continuing via the blow molding device 30, while the preforms 1 are transformed into finished containers 2 on the forming wheel 32, continuing onto the discharge wheel 70, and finally ending at the discharge device 70a, corresponds to this transport path through the illustrated overall arrangement. In the context of the present disclosure, the separating wheel 40, the transfer wheel 60, and the discharge wheel 70 are generally referred to as "transfer devices" or "transfer wheels."

The forming stations 31 of the blow molding device 30, e.g., in a manner known per se and therefore not shown, consist of multi-part outer molds, against whose inner contours the preforms 1 are expanded by means of compressed air or filling material. A machine housing 37a, 37b is indicated by dotted lines.

There is a control unit 20 of the forming device 30. This control unit 20 could also control the heating device 50 or other control functions of the overall device. However, it is also conceivable that additional control units could be provided to perform these additional control functions.

According to one embodiment, sterilizing fluid is used to sterilize the preforms 1 before or upon entry into the heating device 50 into the interior of the preform 1. Within the scope of the present disclosure, the application of the sterilizing fluid to an outer surface of the preform 1 and optionally the introduction of the sterilizing fluid into the interior, for example, within a 1 The pressure can be applied by means of the pressure device 43, which is not shown in detail. 2 shown in more detail. The preform 1 can be at least partially and/or temporarily sealed after the sterilizing fluid has been introduced into the interior, e.g., by a transport mandrel that guides the preform through the heating device 50. In any case, the preform is exposed to the sterilizing fluid in the exposure device 43 before the heating device, ie, the preforms 1 pass through the exposure device 43 before they enter the heating device.

After sterilization, the preforms 1 are preferably rinsed with a sterile fluid. The rinsing fluid can be sterile air, for example. Inert gases, such as nitrogen or carbon dioxide (also referred to as carbon dioxide), can also be used as a rinsing fluid. One possible rinsing fluid could also be steam. The rinsing fluid is advantageously selected with regard to the subsequent filling material, which may be used for forming. In the case of a carbonized filling material, carbon dioxide, for example, could be a preferred rinsing fluid. The rinsing fluid is generally gaseous, i.e., a rinsing gas. The rinsing step is preferably carried out after the preforms have left the heating device, or immediately before or upon leaving the heating device.

2 is a simplified schematic representation of a section of 1 Here, the separating wheel 40 is divided into a first transfer wheel 40-1 and a second transfer wheel 40-2. Furthermore, a device for applying sterilizer fluid 43 is made visible or arranged between the feed 40a for the preforms 1 and the first transfer wheel 40-1. An irradiation device 100 is provided along the transport path of the preforms 1, which is defined, among other things, by the transfer wheels 40-1 and 40-2. This irradiation device 100 has a plurality of radiation sources 101. These radiation sources 101 emit UV radiation and particularly preferably UV-C radiation. Furthermore, in the context of the present disclosure, the radiation sources or UV emitters are preferably to be understood as UV-C emitters. In this context, UV-C lamps are lamps that have a particularly strong emission in a wavelength range from 200 nm to 280 nm, and preferably also at 254 nm. The term UV-C lamps encompasses all common types of lamps, such as diodes (light-emitting diodes such as LEDs), mercury vapor lamps, excimer lamps, and others.

It is advantageous if the preforms 1 are rotated about their longitudinal axis during transport through the irradiation device 100. This allows the UV radiation to impinge as evenly as possible on the entire outer surface of the preform 1. In certain embodiments, the radiation sources 101 can then be provided on only one side of the transport path, thus reducing the number of required radiation sources and the complexity of the arrangement.

In the embodiment shown here with two transfer wheels 40-1 and 40-2, the preform 1 follows a first partial revolution TU1 of the first transfer wheel 40-1 and then a second partial revolution TU2 of the second transfer wheel 40-2. This results in a meandering transport path for the preforms 1. The length of the transport path through the irradiation device 100, i.e. the time during which the preforms 1 are exposed to irradiation, can be selected such that as much of the sterilizing fluid on the outer surface as possible is activated by the radiation sources (preferably UV-C lamps) and has thus already disintegrated or disappeared before entering the heating device 50.

The radiation sources 101 are preferably designed as UV-C lamps and distributed along the transport path. The irradiation device 100 (and with it the radiation sources 101) thus follows, in a curved manner, a first partial revolution of the preforms 1 around the first transfer wheel 40-1 and a second partial revolution of the preforms 1 around the second transfer wheel 40-2. The distance between the radiation sources and the preforms guided along them preferably remains constant.

The preforms are held along the transfer wheels 40-1 and 40-2 by grippers 44 (44-1 and 44-2). These grippers 44-1, 44-2 can preferably hold the preforms 1 above or below a neck ring 6 (see 3 ) between the first transfer wheel 40-1 and the second transfer wheel 40-2, a transfer takes place from the grippers 44-1 of the first transfer wheel 40-1 to the grippers 44-2 of the second transfer wheel 40-2. During the transfer, a re-gripping is provided such that the grippers 44-1 of the first transfer wheel 40-1 grip the preform 1 at a first gripping area and the grippers 44-2 of the second transfer wheel 40-2 grip the preform 1 at a second gripping area, wherein the first gripping area area is different from the second engagement area, and the two engagement areas advantageously do not overlap. This ensures that the areas in which the grippers 44-1 or 44-2 cover or shade the outer surface of the preform in one of the engagement areas also receive sufficient UV-C radiation.

Alternatively, the preforms 1 can be guided along the first and/or second transfer wheels 40-1 and 40-2 and through the irradiation device 100 with transport mandrels which are only arranged in the mouth region 3 (cf. 3 ) of the preforms 1 in a clamping manner.

A housing 110 is provided along the transport path between the application device 43 for the sterilizing fluid and the end of the irradiation device 100. This housing preferably also extends along the application device 43, thus also serving as the housing for the application device 43. However, a housing for the application device 43 can also be directly adjacent to the housing 110. In this respect, in one possible embodiment, the irradiation device 100 could also extend at least slightly into the application device 43, such that the irradiation with UV-C radiation occurs as soon as possible after the application of the sterilizing fluid to the outer surface of the preforms 1.

The 3A and 3B each show a simplified schematic lateral representation of a preform 1 passing through the irradiation device 110. 3A shows the preform 1 during a first partial revolution TU1 around the first transfer wheel 40-1. The preform 1 comprises three regions, namely the mouth region 3, the shaft 4 (also side or lateral region), and the tip 5. The preform 1 also has a neck ring 6. During the first partial revolution TU1 around the first transfer wheel 40-1, the preform 1 is held above the neck ring 6 by a first gripper 44-1 (indicated by dashed lines). In addition, the preform 1 is irradiated from the outside with UV-C radiation by the UV radiation sources or UV-C radiators 101-1, 101-2, 101-3, and 101-4. Optionally, additional lamps 101-5, 101-6 can also be provided, which expose the preform 1 to UV-C radiation from the opposite side. Condensed sterilizing fluid is present on the outer surface, particularly in the areas of the mouth section 3, the shaft 4, and the dome 5, as well as, of course, the neck ring 6. This fluid is activated by the UV-C radiation. During the first and second partial cycles TU1, TU2, the sterilizing fluid gradually evaporates (through activation and decomposition). 3B shows the preform 1 during the second partial revolution TU2 around the second transfer wheel 40-2. The second gripper 44-2 of the second transfer wheel 40-2 now engages below the neck ring 6. As a result, areas covered and shaded by the first gripper 40-1 during the first partial revolution TU1 are released and can be reached by the UV-C radiation during the second partial revolution TU2. The condensed sterilization fluid located there is thereby activated. In addition, as a result of the transfer from the first transfer wheel 40-1 to the second transfer wheel 40-2, the preform 1 has rotated approximately 180° around its own longitudinal axis LA (as shown below) relative to the UV-C lamps 101-1, 101-2, and 101-3. The preform 1 now receives UV radiation on the other side. This enables a one-sided arrangement of the UV radiation sources along the transport path. Preferably, however, the preform 1 is rotated about its longitudinal axis (LA) on at least one partial revolution TU1, TU2, more preferably on both partial revolutions TU1, TU2, with the advantages mentioned in the general description. Optionally, additional UV-C lamps 101-5 and 101-6 can also be provided on the second partial revolution TU2, which irradiate the preform 1 from the opposite side, so that irradiation with UV-C radiation occurs on both sides during one or both partial revolutions.

The housing 110 can be mounted laterally or comprehensively and is either closed off from one side by the respective transfer wheel 40-1, 40-2 or continued on the side of the respective transfer wheel 40-1, 40-2. The housing 110 can also extend at least partially beneath the preform 1, at least as a support for a UV lamp 101-4 on the top.

The enclosure 110 is designed to shield UV radiation in a direction away from the preform 1 and, if applicable, the transfer wheels 40-1 and 40-2, and to prevent the evaporating sterilizing fluid from escaping. The sterilizing fluid is extracted by the suction devices 120 described herein. Sterile air can be supplied passively or actively to the enclosure 110 by sterile air sources.

The radiators 101-1, 101-2, 101-3, 101-4, 101-5, and 101-6 are mounted at variable spacing and positions. This is illustrated by the arrows P. This allows for different preform geometries to be accommodated. The radiators 101-1, 101-2, 101-3, 101-4, 101-5, and 101-6 can advantageously all be arranged or attached to a single support.

In one embodiment, the preforms 1 enter the heating device 50 after irradiation with UV radiation. Alternatively or additionally, the irradiation can continue into the heating device or take place within the heating device 50, but upstream of the heating section 51 or upstream of the heating devices that heat the preforms. A film of sterilizing fluid is then still present on the inner surface of the preforms 1. The outer surface of the preform is essentially free of sterilizing fluid at this time. Due to the heating of the preforms in the heating device or the heating section, the activation and decomposition of the sterilizing fluid occurs inside the preforms 1, so that the sterilization of the inner region of the preform only takes place in the heating device or in the heating section. The UV lamps 101-1, 101-2, 101-3, 101-4, 101-5, 101-6 do not reach this inner film because the material of the preform 1 is not penetrated by this UV radiation.

4 shows a simplified representation of a further embodiment for the irradiation of the preforms 1. In this embodiment, in addition to or as an alternative to the 3A and/or 3B, the irradiation of the preforms 1 with UV-C lamps 101-1 to 101-7 within the heating device 50 until shortly before the heating section 51, i.e. until shortly before the actual heating of the preforms 1. In this case, the UV irradiation can advantageously be carried out from two sides, since the preforms 1 move in a straight line. This two-sided irradiation is in 2 and 3 by the additional dotted radiators 101-5, 101-6 and 101-7.

Within the heating device 50, the preforms 1 can advantageously be transported using transport mandrels 45. These clamp into the interior (mouth region 3) of the preforms 1. By means of the transport mandrel 45, the preform 1 can advantageously be rotated about its longitudinal axis during irradiation with UV-C radiation.

In some embodiments, the transport mandrels 45 can be used to extract the sterilizing fluid and/or supply sterile air. Such transport mandrels 45 could advantageously be provided, for example, to remove the sterilizing fluid at the end of the transport through the heating device 50 and replace it with sterile air or an inert gas, e.g., through a purging process. In an alternative embodiment, the transport mandrels 45 can also be limited to partially or completely sealing the preform interior from the environment.

List of reference symbols

1

preform

2

finished container

3

Mouth area of the preform

4

Preform shaft

5

Preform tip

11

Mouth section of the preform

20

Control unit

30

Blowing device

31

Forming stations

32

Forming wheel

37a, 37b

Housing walls

40

Transfer wheel/separation wheel

40-1

first transfer wheel, first transfer device

40-2

second transfer wheel, second transfer device

40a

Feeding

43

Application device for sterilizing fluid

44

gripper

45

Transport mandrel

50

Heating device/tempering device

51

Heating section or heating devices along a heating section

60

third transfer wheel

70

Output wheel (fourth transfer wheel)

100

Irradiation device

101

UV radiation source/UV lamp/UV-C lamp

101-1

UV-C lamps on the mouth area

101-2

UV-C lamp on the shaft

101-3UV-C-

Spotlight on the summit

101-4

UV-C lamps on the summit

101-5

UV-C lamps

101-6

UV-C lamps

110

Enclosure

120

Suction device for sterilizing fluid

130

Sterile air source

300

Direction of rotation of the forming wheel of the blowing device

400

Direction of rotation of the separating wheel

500

Direction of rotation of the transport chain within the heating device

600

Direction of rotation of the transfer wheel

700

Direction of rotation of the output wheel

P

Adjustment options for the UV-C lamps

ST

Start of sterilization (supply of sterilizing fluid)

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 23 52 926 A1 [0003]
• DE 43 40 291 A1 [0004]
• DE 42 12 583 A1 [0004]
• WO 2014/139624A1 [0006]
• DE 10 2014 010 283 A1 [0007]
• WO 2010/020530 A1 [0007]
• EP 2 588 295 A1 [0007]

Claims (16)

A method for forming preforms (1) made of a thermoplastic material into containers (2), in which a preform (1) is guided along a transport path through sections of a forming device, the method comprising the following steps: applying a sterilizing fluid to an outer surface of a preform (1) and introducing a sterilizing fluid into an interior space (1) of the preform (1) before heating the preform (1) in a heating device, subsequently irradiating only the outer region of the preform (1) with a UV radiation source (101, 101-1, 101-2, 101-3), preferably a UV-C radiation source, to activate the sterilizing fluid on the outer surface of the preform (1) such that the sterilizing fluid on the outer surface is substantially evaporated before heating the preform (1) in the heating device, and subsequently heating the preform (1) to a forming temperature in the heating device, whereby the heating activates the sterilizing fluid inside the preform. Procedure according to Claim 1 , wherein the sterilizing fluid is supplied in vapor or aerosol form and the preform (1) is at a temperature during this supply which is below the condensation temperature of the vapor or aerosol-form sterilizing fluid, so that the sterilizing fluid precipitates on the surfaces of the preform (1) as condensate, wherein the steam is supplied in such a way that a largely complete condensation film is formed on the outside and optionally inside of the preform (1). Procedure according to Claim 1 or 2 , wherein the preform is rotated about its longitudinal axis relative to the UV radiation source (101, 101-1, 101-2, 101-3, 101-4, 101-5, 101-6, 101-7) by means of a transport device (40, 40-1, 40-2, 44, 45) during irradiation with ultraviolet radiation. Method according to one of the preceding claims, wherein the irradiation of the preform (1) with the UV radiation source (101, 101-1, 101-2, 101-3) takes place along a meandering transport path, namely and during a first partial revolution (TU1) of the preform around a first transfer wheel (40-1) and during a second partial revolution (TU2) around a second transfer wheel (40-2), wherein preferably between the first partial revolution (TU1) around the first transfer wheel (40-1) and the second partial revolution (TU2) around the second transfer wheel (40-2) a change in the gripping region on the preform (1) takes place such that the first gripping region and the second gripping region on the preform are different, in particular have no overlap of gripping surfaces. Method according to one of the preceding claims, wherein irradiation of the preforms (1) with UV-C radiation takes place within the heating device (50) by UV-C radiators (101-1, 101-2, 101-3, 101-4, 101-5, 101-6, 101-7), but before a heating section (51), namely before heating, in particular wherein the preforms (1) are rotated about their longitudinal axis relative to the UV-C radiators (101-1, 101-2, 101-3, 101-4, 101-5, 101-6, 101-7) during irradiation within the heating device (50). Method according to one of the preceding claims, wherein the UV radiation source (101, 101-1, 101-2, 101-3) is constructed in several parts, in particular at least three parts, wherein at least one UV emitter (100-1) is directed onto a mouth section (3) of the preform (1) and at least one UV emitter (100-3) is directed onto a dome (5) of the preform and/or at least one UV emitter (100-2) is directed onto a lateral region, in particular a shaft (4) of the preform (1). Method according to one of the preceding claims, wherein the irradiation with UV radiation takes place within a shielding housing (110) which extends at least from the location of the application of sterilizing fluid to the end of the irradiation with UV radiation, has a suction device and is configured to shield the UV radiation and to suck out volatile sterilizing fluid. A device for forming preforms (1) made of a thermoplastic material into containers (2), wherein the preforms (1) are guided downstream within the forming device along a transport path by means of at least one transport device (40-1, 40-2, 44-1, 44-2, 45), and wherein the device comprises the following along the transport path in the downstream direction: a feed device (40a) for feeding a preform (1) into the forming device, an application device (43) for applying a sterilizing fluid to an outer surface (3, 4, 5) of the preform (1) and for introducing the sterilizing fluid into the interior of the preform (1), an irradiation device (100) with one or more UV radiation sources (101, 101-1, 101-2, 101-3, 101-4, 101-5, 101-6, 101-7), in particular with UV-C radiation sources, for irradiating the outer surface (3, 4, 5) of the preform (1) with UV radiation, a heating device (50) with heating devices (51) along a heating section for heating the preform (1) to a forming temperature, wherein the application device (43), the irradiation device (100) and the heating device (50) are set up and coordinated with one another in such a way that in the irradiation device (100) only the sterilizing fluid located on the outer surface (3, 4, 5) of the preform (1) is activated and has substantially evaporated before the preform (1) enters the heating device (50), and in the heating device (50) the sterilizing fluid in the interior of the preform (1) is activated. Device according to Claim 8 , wherein the transport device is designed such that the preform (1) performs a rotation about its own longitudinal axis (LA) relative to the UV radiation source (101, 101-1, 101-2, 101-3, 101-4, 101-5, 101-6, 101-7) during the irradiation with the UV radiation source (101, 101-1, 101-2, 101-3, 101-4, 101-5, 101-6, 101-7). Device according to Claim 8 or 9 , wherein the device comprises a first and a second transport device (40-1, 40-2), in particular a first and a second transfer wheel, wherein the UV radiation source (101, 101-1, 101-2, 101-3, 101-4, 101-5, 101-6) is arranged along the meandering transport path, in particular following a first partial section (TU1) along the first transport device (40-1) and following a second partial section (TU2) along the second transport device (40-2), such that the distance between the UV radiation sources (101, 101-1, 101-2, 101-3, 101-4, 101-5, 101-6) and the preform remains substantially the same. Device according to Claim 10 , wherein the first transport device (40-1) has first grippers (44-1) and is set up to grip the preform (1) with the first grippers (44-1) at a first gripping region during the first partial section (TU1), and the second transport device (40-2) has second grippers (44-2) and is set up to grip the preform (1) with the second grippers (44-2) at a second gripping region during the second partial section (TU2), wherein the first gripping region is different from the second gripping region, in particular wherein the gripping regions do not overlap. Device according to one of the Claims 8 until 11 , wherein UV-C radiators (101-1, 101-2, 101-3, 101-4, 101-5, 101-6, 101-7) are arranged within the heating device (50) and before entering a heating section (51), in particular on both sides of the preforms (1). Device according to Claim 8 until 12 , wherein the UV radiation source (101, 101-1, 101-2, 101-3) of the irradiation device (100) is constructed in several parts and comprises at least one UV radiation source (101-1) which is directed towards a mouth section (3) of the preform (1), and at least one UV radiation source (101-3) which is directed towards a dome (5) of the preform (1), and at least one UV radiation source (101-2) which is directed towards a shaft (4) of the preform (1), in particular wherein at least one of the radiation sources (101-1, 101-2, 101-3) is adjustable with regard to its distance from the preform (1), in particular with regard to its distance from the dome (5) of the preform (1). Device according to one of the Claims 8 until 13 , wherein the irradiation device (100) has a housing (110), in particular a housing (110) which is designed as a tunnel, wherein the housing (100) is designed to shield the ultraviolet radiation of the UV radiation sources (101, 101-1, 101-2, 101-3) in a direction facing away from the preform (1). Device according to Claim 14 , wherein the housing (110) comprises a suction device (120) for volatile sterilizing fluid, which is configured to suck volatile sterilizing fluid out of the housing (110). Device according to Claim 15 , wherein the device comprises a sterile air source (130) which is connected to the housing (110) and is arranged for the subsequent flow or supply of sterile air.