DE102007050582A1 - Method and device for sterilizing and device for blow molding of containers - Google Patents

Abstract

The Method and apparatus are used to sterilize workpieces from a thermoplastic material in the production of blow-molded Containers. The workpieces can as Preforms or formed as a blow-molded container be. The sterilization is done by applying an electron beam carried out. A sterilizer is this with provided a generator for electron radiation. Especially can the sterilizer in the field of a device for Blow molding of containers along a transport path the preforms and / or the blow-molded container become. The electron radiation is at a radiation intensity of at least 15 kRay in the area of the surface to be sterilized directed.

Description

The The invention relates to a method for sterilizing workpieces from a thermoplastic material in the production of blow-molded Containers.

About that In addition, the invention relates to a method for blow molding at least partially sterile containers.

After all The invention relates to a device for sterilizing workpieces from a thermoplastic material in the production of blow-molded Containers. Also of the invention is a device for the production of at least partially sterile workpieces of a thermoplastic material.

The The invention also relates to a device for blow molding containers, the at least one blowing station arranged on a support structure for forming thermoplastic preforms into the containers having.

A Manufacture of sterile blow-molded containers takes place typically such that these containers after their blow molding and before filling using be sterilized by hydrogen peroxide or other chemicals. It is also already known that in the blow molding of the container to sterilize preforms used as starting material, in particular the area of the inner surface of these preforms.

It is also already known that in the implementation a coating of containers using a Plasmas sterilization effects occur. Because of the usual provided contours in the area of the container walls occur in such sterilizations but so-called shadowing which stand in the way of reliable sterilization.

As a general rule is used in the sterilization of containers and preforms between a wet sterilization using liquid Sterilization agents and a dry sterilization, for example using dried hot air or superheated steam, distinguished. Another way to sterilize Preforms or containers are in use of high energy radiation to kill bacterial spores and germination.

In a container forming by Blasdruckeinwirkung preforms of a thermoplastic material, such as preforms of PET (poly ethylene terephthalate), supplied to different processing stations within a blow molding machine. Typically, such a blow molding machine has a heating device and a blowing device, in the region of which the previously tempered preform is expanded by biaxial orientation to form a container. The expansion takes place with the aid of compressed air, which is introduced into the preform to be expanded. The procedural sequence in such an expansion of the preform is in the DE-OS 43 40 291 explained.

The basic structure of a blowing station for container molding is in the DE-OS 42 12 583 described. Possibilities for tempering the preforms are in the DE-OS 23 52 926 explained.

Within The apparatus for blow molding, the preforms as well as the blown containers using different ones Handling facilities are transported. proven In particular, the use of transport thorns, to which the preforms are attached. The preforms can but also be handled with other support devices. The usage grippers for handling preforms and use of expanding mandrels for holding in a mouth area of the preform are also included to the available constructions.

Handling of containers using transfer wheels, for example, in the DE-OS 199 06 438 in an arrangement of the transfer wheel between a blowing wheel and an output path described.

The already explained handling of the preforms takes place on the one hand in the so-called two-stage procedure, in which the First, preforms in an injection molding process produced, then stored temporarily and later conditioned in temperature and to a container be inflated. on the other hand, an application in the so-called One-step process in which the preforms immediately after their injection molding production and a sufficient Solidification suitable tempered and then inflated become.

in the With regard to the blowing stations used are different Embodiments known. For blow molding stations that rotate Transport wheels are arranged, is a book-like Aufklappbarkeit the mold carrier frequently encountered. But it is also possible, relative to each other displaceable or different to use guided mold carriers. In fixed Blowing stations, which are particularly suitable for several Cavities for container forming, be typically parallel to each other arranged plates as a mold carrier used.

task It is the object of the present invention to provide a method of the mentioned type to improve that in a simple manner a reliable sterilization can be performed can.

These The object is achieved according to the invention that the sterilization by application of electron radiation is performed, wherein the electron beam with a Radiation intensity of at least 15 kRay on the surface of the Workpiece is passed.

Further Object of the present invention is to provide a device of Initially mentioned type to construct such that a effective sterilization with little effort feasible is.

These The object is achieved according to the invention in that at least one sterilization unit is a generator for electron radiation, wherein the generator a power output for generating a radiation intensity in the area of a surface of the workpiece of 15 kRay.

After all It is an object of the present invention to provide a device for the blow molding of containers of the initially mentioned Art to construct such that the production of sterile Containers is supported.

These The object is achieved according to the invention that along a part of a transport path of the preforms and / or the container arranged a sterilization unit is that with a generator for electron radiation is provided.

For a variety of applications, it is sufficient that a Inner surface of the workpieces sterilized becomes.

About that but it is also thought that an external Surface of the workpieces is sterilized.

A Effective sterilization is realized by everyone Part of the surface of the workpiece of one Electron beam is applied.

A advantageous orientation of the radiation source is effected in that the Electron beam with an angular range of 0 to 15 ° relative aligned to a surface normal of the surface becomes.

A structurally simple realization is supported by the electron beam is generated by a radiation source becomes.

A Another variant is that the Electron beam generated by at least two radiation sources becomes.

A uniform loading of the workpiece in a circumferential direction is facilitated by the Workpiece while performing the Sterilisationsvorganges at least temporarily in a rotation to its longitudinal axis is offset.

to Loading the surface of the workpiece in a longitudinal direction it is proposed that the Sterilization unit at least temporarily during the execution the sterilization process is pivoted.

According to one Embodiment is provided that as a workpiece a preform is sterilized.

A Arrangement of the sterilizer, for example, such take place that the preform in the region of a feed line is sterilized.

A Another arrangement variant is provided by a Sterilization of the preforms in the transport direction in front of a heating section and after a performed arrangement of the preforms with constant distances relative to each other becomes.

One Another field of application is opened up by the fact that Workpiece blown container sterilized becomes.

For example It is thought that the container in the area a delivery line is sterilized.

Also is it possible that the container is in the area a transfer wheel is sterilized.

A Another constructive realization is that the Sterilization unit is arranged slidably.

One compact construction of the device is thereby supported, that the sterilization unit at least partially rod-like is trained.

In The drawings are embodiments of the invention shown schematically. Show it:

1 A perspective view of a blowing station for the production of containers from preforms,

2 a longitudinal section through a blow mold, in which a preform is stretched and expanded,

3 a sketch to illustrate a basic structure of a device for blow molding containers,

4 a modified heating section with increased heating capacity,

5 a longitudinal section through a preform with laterally adjacent to the preform pivotally arranged sterilizer,

6 one opposite 5 modified embodiment with a displaceably arranged sterilizer,

7 a further modified embodiment with a pivotable sterilizer for sterilizing an inner surface of the preform,

8th an embodiment with a rod-like sterilizing device for insertion into an interior of the preform,

9 a schematic representation of a sterilizer for sterilizing the inner surface of a container and

10 a schematic representation of a sterilizer for sterilizing the outer surface of a container.

In front an explanation of the detailed structure of the device for Sterilization of the workpieces by application of electron radiation and before an explanation of a concrete installation of a corresponding device in a blow molding machine will be below First, the basic structure of a blow molding machine to be discribed.

The basic structure of a device for forming preforms ( 1 ) in containers ( 2 ) is in 1 and in 2 shown.

The device for forming the container ( 2 ) consists essentially of a blowing station ( 3 ), which are blown ( 4 ) into which a preform ( 1 ) insertion bar is. The preform ( 1 ) may be an injection-molded part of polyethylene terephthalate. To enable insertion of the preform ( 1 ) in the blow mold ( 4 ) and to allow removal of the finished container ( 2 ) the blow mold ( 4 ) from mold halves ( 5 . 6 ) and a bottom part ( 7 ), which by a lifting device ( 8th ) is positionable. The preform ( 1 ) in the area of the blowing station ( 3 ) of a transport mandrel ( 9 ), which together with the preform ( 1 ) passes through a plurality of treatment stations within the device. But it is also possible to use the preform ( 1 ), for example via pliers or other handling means directly into the blow mold ( 4 ).

To enable a compressed air supply line is below the transport mandrel ( 9 ) a connecting piston ( 10 ) disposed of the preform ( 1 ) Supplies compressed air and at the same time a seal relative to the transport mandrel ( 9 ). In a modified construction, it is basically also conceivable to use solid compressed air supply lines.

A stretching of the preform ( 1 ) takes place with the aid of a stretching rod ( 11 ), by a cylinder ( 12 ) is positioned. Basically, it is also conceivable, a mechanical positioning of the stretch rod ( 11 ) via curve segments that are acted upon by Abgriffrollen. The use of curve segments is particularly useful when a plurality of blow molding stations ( 3 ) are arranged on a rotating blowing wheel. A use of cylinders ( 12 ) is useful when stationarily arranged blow molding stations ( 3 ) are provided.

At the in 1 illustrated embodiment, the stretching system is designed such that a tandem arrangement of two cylinders ( 12 ). From a primary cylinder ( 13 ), the stretch rod ( 11 ) first before the beginning of the actual stretching process into the area of a soil ( 14 ) of the preform ( 1 ) hazards. During the actual stretching process, the primary cylinder ( 13 ) with extended stretch rod together with a primary cylinder ( 13 ) carrying carriages ( 15 ) from a secondary cylinder ( 16 ) or via a cam control. In particular, the secondary cylinder ( 16 ) such a cam-controlled use that of a leadership role ( 17 ), which slides along a curved path during the execution of the stretching process, a current stretching position is specified. The leadership role ( 17 ) is from the secondary cylinder ( 16 ) pressed against the guideway. The sled ( 15 ) slides along two guide elements ( 18 ).

After closing in the range of girders ( 19 . 20 ) arranged mold halves ( 5 . 6 ) there is a locking of the carrier ( 19 . 20 ) relative to each other by means of a locking device ( 40 ).

For adaptation to different shapes of a mouth section ( 21 ) of the preform ( 1 ) is according to 2 the use of separate thread inserts ( 22 ) in the area of the blow mold ( 4 ) intended.

2 shows in addition to the blown container ( 2 ) also shown in dashed lines the preform ( 1 ) and schematically a developing container bubble ( 23 ).

3 shows the basic structure of a blow molding machine with a heating line ( 24 ) and a rotating blowing wheel ( 25 ) is provided. Starting from a preform input ( 26 ), the preforms ( 1 ) of transfer wheels ( 27 . 28 . 29 ) in the area of the heating section ( 24 ). Along the heating route ( 24 ) are radiant heaters ( 30 ) as well as blowers ( 31 ) arranged to the preforms ( 1 ) to temper. After a sufficient temperature of the preforms ( 1 ) these are to the blowing wheel ( 25 ), in whose area the blowing stations ( 3 ) are arranged. The finished blown containers ( 2 ) are provided by further transfer wheels of a delivery line ( 32 ).

To get a preform ( 1 ) into a container ( 2 ) that the container ( 2 ) Has material properties which have a long useful life from inside the container ( 2 ), in particular beverages, special process steps in the heating and orientation of the preforms ( 1 ) be respected. In addition, advantageous effects can be achieved by adhering to special dimensioning regulations.

When thermoplastic material can be different plastics be used. Useful are, for example, PET, PEN or PP.

The expansion of the preform ( 1 ) during the orientation process is carried out by compressed air supply. The compressed air supply is in a Vorblasphase in which gas, for example, compressed air, is supplied at a low pressure level and divided into a subsequent Hauptblasphase in which gas is supplied at a higher pressure level. During the pre-blowing phase, compressed air is typically used at a pressure in the interval of 10 bar to 25 bar and during the main blowing phase compressed air is supplied at a pressure in the interval of 25 bar to 40 bar.

Out 3 is also apparent that in the illustrated embodiment, the heating section ( 24 ) from a plurality of circulating transport elements ( 33 ) is formed, the chain-like strung together and along deflection wheels ( 34 ) are guided. In particular, it is envisaged to open a substantially rectangular basic contour by the chain-like arrangement. In the illustrated embodiment, in the region of the transfer wheel ( 29 ) and an input wheel ( 35 ) facing the extent of the heating section ( 24 ) a single relatively large-sized deflection ( 34 ) and in the region of adjacent deflections two comparatively smaller dimensioned deflection wheels ( 36 ) used. In principle, however, any other guides are conceivable.

To enable a dense arrangement of the transfer wheel ( 29 ) and the input wheel ( 35 ) relative to each other, the arrangement shown to be particularly useful, since in the region of the corresponding extent of the heating section ( 24 ) three deflection wheels ( 34 . 36 ), in each case the smaller deflection wheels ( 36 ) in the area of the transition to the linear curves of the heating section ( 24 ) and the larger deflection wheel ( 34 ) in the immediate transfer area to the transfer wheel ( 29 ) and to the input wheel ( 35 ). Alternatively to the use of chain-like transport elements ( 33 For example, it is also possible to use a rotating heating wheel.

After a finished blowing of the container ( 2 ), these are picked up by a picking wheel ( 37 ) from the field of blowing stations ( 3 ) and via the transfer wheel ( 28 ) and an output wheel ( 38 ) to the output section ( 32 ).

In the in 4 illustrated modified heating section ( 24 ) can by the larger number of radiant heaters ( 30 ) a larger amount of preforms ( 1 ) are tempered per unit time. The blowers ( 31 ) direct cooling air into the area of cooling air ducts ( 39 ), which the associated radiant heaters ( 30 ) in each case opposite and deliver the cooling air via outflow openings. Due to the arrangement of the outflow directions, a flow direction for the cooling air is substantially transverse to a transport direction of the preforms ( 1 ) realized. The cooling air channels ( 39 ) in the area of the radiant heaters ( 30 ) opposite surfaces provide reflectors for the heating radiation, it is also possible on the discharged cooling air and a cooling of the radiant heater ( 30 ) to realize.

5 shows a longitudinal section through a preform ( 1 ). The preform ( 1 ) has a wall ( 41 ), which have an outer surface ( 42 ) and an interior ( 43 ) facing inner surface ( 44 ) is provided. On the outside next to the preform ( 1 ) is a sterilization unit ( 45 ), which is formed as an electron beam generator and an electron beam ( 46 ) towards the outer surface ( 42 ). In the illustrated embodiment, the sterilizer ( 45 ) in the direction of a longitudinal axis ( 47 ) of the preform ( 1 ) arranged pivotably.

The preform ( 1 ) during its sterilization process about its preform longitudinal axis ( 47 ) in a rotation around. For example, it is possible, in each case after a complete rotation through 360 °, to pivot the sterilization unit (FIG. 45 ) in such a way that successively in the direction of the longitudinal axis ( 47 ) one after the other ring-like or sleeve-like segments of the outer surface ( 42 ) are sterilized.

6 shows one opposite 5 modified embodiment in which the sterilization unit ( 45 ) is not pivotable, but in the direction of the longitudinal axis ( 47 ) is arranged displaceably. In particular, the sterilization unit ( 45 ) substantially parallel to the longitudinal axis ( 47 ), so that a constant distance between the sterilization unit ( 45 ) and the outer surface ( 42 ) is guaranteed. In principle, it is also possible to have both a displaceability and a pivotability of the sterilization unit ( 45 ) to realize.

According to the embodiment in FIG 7 is the sterilization unit ( 45 ) near the mouth section ( 21 ) of the preform ( 1 ) arranged. The arrangement of the sterilization unit ( 45 ) takes place in such a way that the electron beam ( 46 ) through a mouth opening ( 48 ) of the preform ( 1 ) in the interior ( 43 ) and here on the inner surface ( 44 ). Preferably, the sterilization unit ( 45 ) pivotally arranged to different sterilization areas in the direction of the longitudinal axis ( 47 ). Also for such internal sterilization of the preform ( 1 ), it proves to be expedient to use the preform ( 1 ) during the sterilization process in a rotational movement about the longitudinal axis ( 47 ) around.

In the case of pivotable sterilization units ( 45 ), it is possible to perform the panning operation continuously or stepwise. In an overlay with a rotational movement of the preform ( 1 In this way, either the already mentioned annular sterilization areas or a spirally extending sterilization area can be generated.

8th shows a further modified embodiment in which a rod or tubular sterilization unit ( 45 ) in the interior ( 43 ) of the preform ( 1 ) is retracted. The sterilization unit ( 45 ) is in this case in the direction of the longitudinal axis ( 47 ) positionable. The electron beam ( 46 ) can either be fan-shaped to 360 °, or at a certain time only a certain angle section of the inner surface ( 44 ). In such a focusing of the electron beam ( 46 ), the sterilization unit ( 45 ) and / or the preform ( 1 ) about the longitudinal axis ( 47 ) turned around. Between the rod-shaped sterilization unit ( 45 ) and the inner surface ( 44 ) extends a distance ( 49 ).

All in the 5 to 8th illustrated arrangements and modes of operation of the sterilization unit ( 45 ) can also be used to sterilize blown containers ( 2 ) be used. 9 shows by way of example the arrangement of a sterilization unit ( 45 ) in the container ( 2 ) and 10 an arrangement on the outside next to the container ( 2 ).

The electron beam ( 46 ) can be generated in all embodiments either from one or more electron beam sources. It is also possible to use the electron beam generated by one or more electron beam sources ( 46 ) in a uniform electron beam or several different beam paths in the direction of the preform ( 1 ) or the container ( 2 ). Typically, the electron beam ( 46 ) is aligned with its major axis substantially perpendicular to the surface to be sterilized. Typically, a corresponding alignment range is in the range of 0 to 15 °, wherein in addition the already explained pivoting movements can be performed.

A typical strength of electron radiation is chosen such that in every surface area to be sterilized reaches a radiation intensity of at least 15 kRay is. This results in a sterilization of at least log 3 in terms of Germs, bacteria and spores reached.

In a sterilization of preforms ( 1 ), the sterilizer unit ( 45 ) in the preform input area ( 26 ), a transfer wheel ( 27 . 29 ) or in the area of the heating section ( 24 ). In case of sterilization of blown containers ( 2 ), an arrangement of the sterilization unit ( 45 ) typically in the region of a transfer wheel or in the region of the delivery path ( 32 ).

In order to maintain the achieved sterility, it is particularly conceivable to use the blown containers ( 2 ) after leaving the blowing station ( 3 ) in sterile air, which in particular is provided with a laminar flow. Preferably, the blown containers ( 2 ) is transported under such sterile conditions into the region of a filling device.

For a positionable sterilizer ( 45 ), the respective positioning, for example, the implementation of a pivoting movement or a displacement, using a pneumatic cylinder, an electric drive or cam-controlled.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 4340291 [0008]
• - DE 4212583 [0009]
• - DE 2352926 [0009]
• - DE 19906438 [0011]

Claims (32)

Method for sterilizing workpieces made of a thermoplastic material in the production of blow-molded containers, characterized in that the sterilization is carried out by applying an electron beam, wherein the electron radiation with a radiation intensity of at least 15 kRay is directed onto the surface of the workpiece. Method according to claim 1, characterized in that that an inner surface of the workpiece is sterilized. Method according to claim 1, characterized in that that an outer surface of the Workpiece is sterilized. Method according to one of Claims 1 to 3, characterized in that each part of the surface of the workpiece is guided by an electron beam ( 46 ) is applied. Method according to one of Claims 1 to 4, characterized in that the electron beam ( 46 ) is aligned with an angle range of 0 to 15 ° relative to a surface normal of the surface. Method according to one of claims 1 to 5, characterized in that the electron beam of a radiation source is generated. Method according to one of claims 1 to 5, characterized in that the electron beam of at least two radiation sources is generated. Method according to one of claims 1 to 7, characterized in that the workpiece during performing the sterilization process at least temporarily shifted in a rotation about its longitudinal axis becomes. Method according to one of claims 1 to 8, characterized in that the sterilization unit ( 45 ) is pivoted at least temporarily during the performance of the sterilization process. Method according to one of claims 1 to 9, characterized in that a preform ( 1 ) is sterilized. Method according to claim 10, characterized in that the preform ( 1 ) in the region of a feed line ( 26 ) is sterilized. Process according to claim 10, characterized in that the sterilization of the preforms ( 1 ) in the transport direction in front of a heating section ( 24 ) and after an arrangement of the preforms ( 1 ) is performed at constant intervals relative to each other. Method according to one of claims 1 to 9, characterized in that a blown container ( 2 ) is sterilized. Method according to claim 13, characterized in that the container ( 2 ) is sterilized in the region of a discharge line. Method according to claim 13, characterized in that the container ( 2 ) is sterilized in the region of a transfer wheel. Method according to one of claims 1 to 15, characterized in that the workpiece together with the sterilizing device ( 47 ) is moved along a transport path. Device for sterilizing workpieces made of a thermoplastic material in the production of blow-molded containers, characterized in that at least one sterilizing device ( 45 ) comprises a generator for electron radiation, wherein the generator has a power output for generating a radiation intensity in the region of a surface of the workpiece of at least 15 kRay. Apparatus according to claim 17, characterized in that the sterilizing device ( 45 ) is designed to act on the entire area of the surface of the workpiece to be sterilized. Apparatus according to claim 17 or 18, characterized in that the sterilization unit ( 45 ) is aligned with a main radiation direction in a range of 0 to 15 ° relative to a surface normal of the surface to be sterilized. Device according to one of claims 17 to 19, characterized in that the sterilization unit ( 45 ) has an electron beam source. Device according to one of claims 17 to 19, characterized in that the sterilization unit ( 45 ) has at least two electron beam sources. Device according to one of claims 17 to 21, characterized in that the to be sterilized Workpiece is coupled with a rotary drive. Device according to one of claims 17 to 22, characterized in that the sterilization direction ( 45 ) is arranged pivotably. Device according to one of claims 17 to 23, characterized in that the sterilization unit ( 45 ) for the sterilization of preforms ( 1 ) is trained. Device according to claim 24, characterized in that the sterilization unit ( 45 ) in the region of a feed section of the preforms ( 1 ) is arranged. Device according to claim 24, characterized in that the sterilization unit ( 45 ) in a transport direction of the preforms ( 1 ) in front of a heating section ( 24 ) is arranged. Device according to one of claims 17 to 23, characterized in that the sterilization unit ( 45 ) for the sterilization of blown containers ( 2 ) is trained. Apparatus according to claim 27, characterized in that the sterilization unit ( 45 ) in the region of a discharge path of the containers ( 2 ) is arranged. Apparatus according to claim 27, characterized in that the sterilization unit ( 45 ) is arranged in the region of a transfer wheel. Device according to one of claims 17 to 29, characterized in that the sterilization unit ( 45 ) is arranged displaceably. Device according to one of claims 17 to 30, characterized in that the sterilization unit ( 45 ) is formed at least partially rod-like. Apparatus for blow-molding of containers, which has at least one Blassta arranged on a support structure tion for forming thermoplastic preforms in the container, characterized in that along a transport path of the preforms ( 1 ) and / or the container ( 2 ) at least one sterilizing device provided with a generator for electron radiation ( 45 ) is arranged.