DE10310470A1 - Method and device for the plasma treatment of workpieces - Google Patents

Abstract

The method and the device are used for the plasma treatment of workpieces. The workpiece is inserted into an at least partially evacuable chamber of a treatment station and the workpiece is positioned within the treatment station by a holding element. The workpiece is acted upon by the holding element in such a way that the workpiece is guided in a variable position in the direction of a longitudinal axis of the cavity. The workpiece is also pressed against a seal in a treatment position with an opening area.

Description

The invention relates to a method for plasma treatment of workpieces in which the workpiece is at least in one partially evacuable plasma chamber Treatment station is used and in which the workpiece within the Treatment station positioned by a holding element becomes.

The invention also relates to a device for Plasma treatment of workpieces that have at least one Evacuable plasma chamber for receiving the workpieces and where the plasma chamber in the area of a Treatment station is arranged, as well as at the plasma chamber of a chamber floor, a chamber cover and one lateral chamber wall is limited and at least one Has holding element for positioning the workpiece.

Such methods and devices are, for example used to make plastics with surface coatings Mistake. In particular, there are already such Methods and devices known to make inner or outer Coating surfaces of containers used for packaging of liquids are provided. Beyond that Devices for plasma sterilization are known.

In PCT-WO 95/22413 a plasma chamber is used Inside coating of bottles made of PET described. The too coating bottles are through a movable bottom lifted into a plasma chamber and in the area of a Bottle mouth associated with an adapter. An evacuation of the Bottle interior done. In addition, the Through a hollow lance into the interior of the adapter Bottles introduced to supply process gas. An ignition of the Plasma is made using a microwave.

From this publication it is already known a plurality of plasma chambers on a rotating wheel to arrange. This will result in a high production rate of Bottles supported per unit of time.

In EP-OS 10 10 773 a feed device explained to evacuate a bottle interior and with To supply process gas. In PCT-WO 01/31680 a Plasma chamber described, in which the bottles of one movable lid that was previously introduced with a Mouth area of the bottles was connected.

PCT-WO 00/58631 also already shows the arrangement of plasma stations on a rotating wheel and describes a group for such an arrangement Assignment of vacuum pumps and plasma stations to one favorable evacuation of the chambers and the interior of the Support bottles. In addition, the Coating of several containers in one Plasma station or a common cavity mentioned.

Another arrangement for performing a Internal coating of bottles is described in PCT-WO 99/17334 described. In particular, an arrangement of a Microwave generator above the plasma chamber and a Vacuum and equipment supply through a bottom of the Plasma chamber described through.

In the vast majority of the known methods, container layers made of silicon oxides with the general chemical formula SiO _x are used to improve the barrier properties of the thermoplastic plastic material. Barrier layers of this type prevent oxygen from penetrating into the packaged liquids and escape of carbon dioxide in the case of liquids containing CO ₂ .

The previously known methods and devices are still not adequate for one Mass production to be used in both low coating price per workpiece as well as a high one Production speed must be achieved.

The object of the present invention is therefore a Procedures of the type mentioned in the introduction such that handling of the workpieces to be treated with high Supported speed and great reliability becomes.

This object is achieved in that the Workpiece is acted upon by the holding element in such a way that the workpiece in the direction of a longitudinal axis of the cavity changed position and in one Treatment positioning with a mouth area against a seal is pressed.

Another object of the present invention is a Device of the type mentioned in the introduction construct a simple kinematics of motion to treating workpieces is supported.

This object is achieved in that the Holding element at least in the direction of one The longitudinal axis of the cavity is arranged in a variable position and that a the holding element supporting base a seal for Has exposure to a mouth region of the workpiece.

By positioning the workpieces within the It is treatment station using the holding element possible to process the workpieces within one Installation for carrying out the process during the Execution of the procedure and during the implementation of a Input and output in the area of the treatment station at a substantially constant height level transport. Only inside the treatment station there is a change in the height level of the workpiece such that this with its mouth area against the Seal is guided so that a seal ensures is. The change in the height positioning of the Workpiece can be synchronized with the execution of others Movements take place so that no additional time is required is caused.

The procedural process for handling the Workpieces are made in such a way that initially for insertion of the workpieces in the plasma chamber an opening of the Plasma chamber takes place at least so far that the workpieces on the Holding element can be passed. In particular is thought of carrying out the transfer in such a way that the Workpieces from a transfer element to the holding element be passed so that no independent Motion drive for the holding element is required. After a Positioning of the workpieces using the holding element within the plasma chamber takes place to a predefinable one Time a lowering of the holding element and thereby one Sealing the interior of the workpiece relative to Interior of the plasma chamber.

Such a seal can already become one Start of the evacuation process as well as after one carried out part evacuation. A seal only after a parts evacuation has the advantage that an interior of the workpiece and the further interior of the Plasma chamber can first be evacuated and that in a second evacuation step after a Sealing the interior of the workpiece the negative pressure in the Area of the interior of the workpiece is different Negative pressure in the interior of the plasma chamber can be specified. In particular, it is thought the negative pressure in the interior of the workpiece is lower than in to specify further interior of the plasma chamber.

After performing the machining process and one Reaching the ambient pressure within the Plasma chamber as well as within the workpiece Transfer of the workpiece from the holding element to another Transfer element. The transfer process is preferably such performed that the transfer element to the Holding element approaches, the workpiece takes over and then that Workpiece removed.

This creates a favorable introduction of gravity supports that the positioning of the clamping elements in a horizontal direction is performed.

A simple implementation of handover processes will supported by the fact that the workpiece of pliers-like Holding arms is positioned.

When coating hollow workpieces with their mouth are arranged downwards, it turns out to be advantageous that an evacuation of a cavity Plasma station takes place through the chamber floor.

A simple technical implementation is also supported by that through the chamber floor Process gas is supplied.

A quick and even distribution of the process gas can be achieved in an interior of the workpiece be that the process gas through a lance in an interior of the workpiece is supplied.

A simple opening and closing of the holding element supported by the fact that the workpiece is pivotable stored holding arms is positioned.

To specify an automatic intake of a Bracket positioning is suggested that the holding arms of Springs are pressed into a locking position.

Inserting the workpiece in the holding element supported by the fact that the holding arms during insertion of the workpiece in the clamping space apart become.

To facilitate removal of the workpiece from the Holding element is proposed that the holding arms pulling the workpiece out of the clamping space apart. In particular, it is thought that Spread apart through direct contact between the workpiece and the holding arms.

To avoid uncontrolled movement of the Holding element in a closed state of the plasma chamber proposed that locking elements for fixing the Holding arms positioned together with the chamber wall become.

This allows a very secure fixation of the workpiece be achieved that at about the same height level how the holding arms a stop element for fixing the Workpiece is arranged.

To support controllable ignition of the plasma it is proposed that in the area of the chamber lid of a microwave generator generated microwaves in the Cavity are initiated.

A typical application is that a workpiece is treated from a thermoplastic.

In particular, it is thought that an interior of the Workpiece is treated.

This makes it an extensive area of application concluded that a container is treated as a workpiece.

In particular, it is thought that as a workpiece a bottle of beverage is being treated.

A high production rate with great reliability and high product quality can be achieved in that the at least one plasma station from a rotating one Plasma wheel from input positioning to one Output positioning is transferred.

An increase in production capacity at only this can result in a slightly increased expenditure on equipment be achieved that several from one plasma station Cavities are provided.

For applications in the field of packaging production for liquids it turns out to be special advantageous that the workpiece in a mouth area of the Holding arms is fixed.

A typical application is defined as: Plasma treatment a plasma coating is carried out.

In particular, it is thought that the plasma treatment performed using a low pressure plasma becomes.

When coating plastic workpieces it proves advantageous that a Plasma polymerization is carried out.

A good surface adhesion is supported by the fact that through the plasma at least partially organic substances be deposited.

Particularly advantageous use properties This allows workpieces for packaging food be achieved by the plasma at least in part inorganic substances are separated.

When it comes to the treatment of packaging, this is particularly important thought that through the plasma a substance for Improved barrier properties of the workpiece deposited becomes.

To support a high quality of use proposed that in addition an adhesion promoter to Improving adherence of the substance to a surface of the Workpiece is deposited.

High productivity can be supported that at least two workpieces in a common cavity be treated at the same time.

Another area of application is that as Plasma treatment a plasma sterilization is carried out.

It is also contemplated that as a plasma treatment Surface activation of the workpiece is carried out.

A resilient provision of the spring forces can in that the spring tension of Leg springs are provided. Alternatively, the Spring forces are also generated by compression springs.

To prevent an unwanted change in one Positioning the workpiece within the plasma chamber suggested that the holding arms in the area of their Fixing projections facing away from extension Locking bars are provided.

This allows a simple mechanical implementation take place that the locking webs of locking elements are fixable.

To support permanent operability too taking into account design tolerances suggested that the locking elements from a hardened Material are formed.

A further improvement of the positioning security of the Workpiece can be caused by the fact that Holding element with a stop element for the workpiece is provided.

For plasma treatment of bottle-like workpieces it proves to be particularly advantageous that the Stop element and the fixing projections on one Height level for loading a bottle-shaped Workpiece between the support ring and the shoulder area are arranged.

Exemplary embodiments of the invention are shown in the drawings shown schematically. Show it:

Fig. 1 is a schematic diagram of a plurality of plasma chambers, which are arranged on a rotating plasma wheel and in which the plasma wheel is coupled to input and output wheels.

Fig. 2 shows an arrangement similar to Fig. 1, wherein the plasma station are each equipped with two plasma chambers,

Fig. 3 is a perspective view of a plasma wheel having a plurality of plasma chambers,

Fig. 4 is a perspective view of a plasma station with a cavity,

Fig. 5 is a front view of the device of FIG. 4 with a closed plasma chamber,

Fig. 6 shows a cross section according to section line VI-VI in Fig. 5,

Fig. 7 is a view corresponding to Fig. 5 with an open plasma chamber,

Fig. 8 is a vertical section according to section line VIII-VIII in Fig. 7,

Fig. 9 is an enlarged representation of the plasma chamber, to be coated bottle according to Fig. 6

Fig. 10 is a perspective view of a provided with two retainer elements support plate, which is intended for a treatment station with two cavities,

Fig. 11 is an enlarged perspective view of one of the retaining elements according to Figs. 10 and

Fig. 12 shows a cross section according to section line XII-XII in Fig. 11.

From the illustration in FIG. 1, a plasma module (1) can be seen which is provided with a rotating plasma wheel (2). A plurality of plasma stations ( 3 ) are arranged along a circumference of the plasma wheel ( 2 ). The plasma stations ( 3 ) are provided with cavities ( 4 ) or plasma chambers ( 17 ) for receiving workpieces ( 5 ) to be treated.

The workpieces ( 5 ) to be treated are fed to the plasma module ( 1 ) in the area of an input ( 6 ) and forwarded via a separating wheel ( 7 ) to a transfer wheel ( 8 ) which is equipped with positionable support arms ( 9 ). The support arms ( 9 ) are arranged pivotably relative to a base ( 10 ) of the transfer wheel ( 8 ), so that a change in the distance of the workpieces ( 5 ) can be carried out relative to one another. As a result, the workpieces ( 5 ) are transferred from the transfer wheel ( 8 ) to an input wheel ( 11 ) with a greater distance between the workpieces ( 5 ) relative to one another relative to the separating wheel ( 7 ). The input wheel ( 11 ) transfers the workpieces ( 5 ) to be treated to the plasma wheel ( 2 ). After the treatment has been carried out, the treated workpieces ( 5 ) are removed from the area of the plasma wheel ( 2 ) by an output wheel ( 12 ) and transferred to the area of an output section ( 13 ).

In the embodiment according to FIG. 2, the plasma stations ( 3 ) are each equipped with two cavities ( 4 ) or plasma chambers ( 17 ). As a result, two workpieces ( 5 ) can be treated at the same time. Basically, it is possible to make the cavities ( 4 ) completely separate from one another, but in principle it is also possible to delimit only partial areas from one another in a common cavity space in such a way that an optimal coating of all workpieces ( 5 ) is ensured. In particular, it is contemplated here to separate the partial cavities from one another at least by means of separate microwave couplings.

Fig. 3 shows a perspective view of a plasma module ( 1 ) with a partially constructed plasma wheel ( 2 ). The plasma stations ( 3 ) are arranged on a support ring ( 14 ) which is designed as part of a rotary connection and is mounted in the area of a machine base ( 15 ). The plasma stations ( 3 ) each have a station frame ( 16 ) which holds plasma chambers ( 17 ). The plasma chambers ( 17 ) have cylindrical chamber walls ( 18 ) and microwave generators ( 19 ).

A rotary distributor ( 20 ) is arranged in a center of the plasma wheel ( 2 ), via which the plasma stations ( 3 ) are supplied with operating resources and energy. Ring lines ( 21 ) can be used in particular for the distribution of operating resources.

The workpieces ( 5 ) to be treated are shown below the cylindrical chamber walls ( 18 ). Lower parts of the plasma chambers ( 17 ) are not shown for the sake of simplicity.

Fig. 4 shows a plasma station ( 3 ) in perspective. It can be seen that the station frame ( 16 ) is provided with guide rods ( 23 ) on which a carriage ( 24 ) for holding the cylindrical chamber wall ( 18 ) is guided. Fig. 4 shows the carriage ( 24 ) with the chamber wall ( 18 ) in a raised state, so that the workpiece ( 5 ) is released.

The microwave generator ( 19 ) is arranged in the upper region of the plasma station ( 3 ). The microwave generator ( 19 ) is connected via a deflection ( 25 ) and an adapter ( 26 ) to a coupling channel ( 27 ) which opens into the plasma chamber ( 17 ). In principle, the microwave generator ( 19 ) can be coupled both directly in the area of the chamber cover ( 31 ) and via a spacer element to the chamber cover ( 31 ) with a predeterminable distance to the chamber cover ( 31 ) and thus in a larger surrounding area of the chamber cover ( 31 ) , The adapter ( 26 ) has the function of a transition element and the coupling channel ( 27 ) is designed as a coaxial conductor. A quartz glass window is arranged in the region of a junction of the coupling channel ( 27 ) in the chamber cover ( 31 ). The deflection ( 25 ) is designed as a waveguide.

The workpiece ( 5 ) is held in the area of a positioning element ( 28 ) which is arranged in the area of a chamber base ( 29 ). The chamber base ( 29 ) is designed as part of a chamber base ( 30 ). To facilitate adjustment, it is possible to fix the chamber base ( 30 ) in the area of the guide rods ( 23 ). Another variant is to attach the chamber base ( 30 ) directly to the station frame ( 16 ). With such an arrangement, it is also possible, for example, to design the guide rods ( 23 ) in two parts in the vertical direction.

FIG. 5 shows a front view of the plasma station ( 3 ) according to FIG. 3 in a closed state of the plasma chamber ( 17 ). The carriage ( 24 ) with the cylindrical chamber wall ( 18 ) is lowered compared to the positioning in FIG. 4, so that the chamber wall ( 18 ) has moved against the chamber bottom ( 29 ). The plasma coating can be carried out in this positioning state.

FIG. 6 shows the arrangement according to FIG. 5 in a vertical sectional view. It can be seen in particular that the coupling channel ( 27 ) opens into a chamber cover ( 31 ) which has a laterally projecting flange ( 32 ). A seal ( 33 ) is arranged in the area of the flange ( 32 ) and is acted upon by an inner flange ( 34 ) of the chamber wall ( 18 ). In a lowered state of the chamber wall (18) therethrough, a seal is made of the chamber wall (18) relative to the chamber lid (31). A further seal ( 35 ) is arranged in a lower region of the chamber wall ( 18 ) in order to ensure a seal here also relative to the chamber bottom ( 29 ).

In the positioning shown in FIG. 6, the chamber wall ( 18 ) encloses the cavity ( 4 ), so that both an interior of the cavity ( 4 ) and an interior of the workpiece ( 5 ) can be evacuated. To support a supply of process gas, a hollow lance ( 36 ) is arranged in the area of the chamber base ( 30 ) and can be moved into the interior of the workpiece ( 5 ). The lance ( 36 ) is positioned by a lance slide ( 37 ) which can be positioned along the guide rods ( 23 ). A process gas channel ( 38 ) runs inside the lance slide ( 37 ) and, in the raised position shown in FIG. 6, is coupled to a gas connection ( 39 ) of the chamber base ( 30 ). This arrangement avoids hose-like connecting elements on the lance slide ( 37 ).

Fig. 7 and Fig. 8 show the arrangement of FIG. 5 and FIG 6 in a raised state of the chamber wall (18).. In this position of the chamber wall ( 18 ), it is possible to remove the treated workpiece ( 5 ) from the area of the plasma station ( 3 ) and to insert a new workpiece ( 5 ) to be treated. As an alternative to the positioning of the chamber wall ( 18 ) shown in the drawings in an open state of the plasma chamber ( 17 ) achieved by displacement upwards, it is also possible to carry out the opening process by displacing a structurally modified sleeve-shaped chamber wall downwards in the vertical direction.

In the exemplary embodiment shown, the coupling channel ( 27 ) has a cylindrical design and is arranged essentially coaxially with the chamber wall ( 18 ).

FIG. 9 shows the vertical section according to FIG. 6 in an enlarged partial illustration in the vicinity of the chamber wall ( 18 ). In particular, the overlapping of the inner flange ( 34 ) of the chamber wall ( 18 ) over the flange ( 32 ) of the chamber cover ( 31 ) and the holding of the workpiece ( 5 ) by the positioning element ( 28 ) can be seen. In addition, it can be seen that the lance ( 36 ) is guided through a recess ( 40 ) in the positioning element ( 28 ).

Fig. 10 shows the arrangement of two positioning elements ( 28 ) in the area of a common support plate ( 41 ). The support plate ( 41 ) with the two positioning elements ( 28 ) is intended for use in the area of a plasma station ( 3 ) for the simultaneous coating of two workpieces ( 5 ). The positioning element ( 28 ) shown in FIG. 10 can also be used for plasma stations ( 3 ) in which only one workpiece ( 5 ) or more than two workpieces ( 5 ) are coated or treated at the same time. Each of the positioning elements ( 28 ) is provided with a holding element ( 46 ) for directly loading the workpieces ( 5 ).

The detailed structure of the positioning elements ( 28 ) is illustrated in FIG. 11 in an enlarged perspective view. The holding element ( 46 ) is designed like pliers and has two pivotably mounted holding arms ( 47 , 48 ). The holding arms ( 47 , 48 ) can be pivoted relative to axes of rotation ( 49 , 50 ). To ensure automatic fixation of the workpiece ( 5 ) by the holding element ( 46 ), the holding arms ( 47 , 48 ) are pressed by springs ( 51 , 52 ) into a respective holding position. The use of leg springs ( 51 , 52 ) is preferred.

The holding element ( 46 ) is arranged above the chamber base ( 30 ), so that after lifting the chamber wall ( 18 ) there is lateral accessibility of the holding element ( 46 ). The workpiece ( 5 ) can hereby be transferred from a positioning element arranged outside the plasma station ( 3 ) to the holding element ( 46 ) without a lifting movement of the workpiece ( 5 ) in the direction of a longitudinal axis ( 53 ) of the cavity before the transfer.

From Fig. 11 it can be seen in particular that a clamping space ( 54 ) for receiving the workpiece ( 5 ) is arranged between the holding arms ( 47 , 48 ). The holding arms ( 47 , 48 ) protrude into the clamping space ( 54 ) with fixing projections ( 55 , 56 ). In addition, the holding arms ( 47 , 48 ) have locking webs ( 57 , 58 ) which face away from the fixing projections ( 55 , 56 ) and which are arranged in one by locking elements ( 59 , 60 ), which can preferably be positioned together with the chamber wall ( 18 ) Locking position can be fixed.

To further support and fix the workpiece ( 5 ), the holding element ( 46 ) has a stop element ( 61 ). The stop element ( 1 ) limits maximum insertion of the workpiece ( 5 ) into the clamping space ( 54 ). In the locking position, the workpiece ( 5 ) is pressed against the stop element ( 61 ) by the fixing projections ( 55 , 56 ). The stop element ( 61 ) and the fixing projections ( 55 , 56 ) are thereby arranged at approximately the same height level.

From Fig. 11 it can also be seen that the holding element ( 46 ) has a base plate ( 62 ) from which the holding arms ( 47 , 48 ) and the other components are carried. The base plate ( 62 ) can be mounted via spacer elements ( 63 , 64 ) and connecting elements ( 65 , 66 ) in the area of the support plate ( 41 ) and together with the latter in the area of the station frame ( 16 ). In particular, it is contemplated to carry out an assembly on the chamber base ( 30 ).

Fig. 11 also shows that the fixing projections ( 55 , 56 ) are each provided with insertion bevels ( 67 ) and outlet bevels ( 68 ). When the workpieces ( 5 ) are inserted into the clamping space ( 54 ), the workpiece ( 5 ) first comes into contact with the insertion bevels ( 67 ) and presses the holding arms ( 47 , 48 ) apart against the forces of the springs ( 51 , 52 ). After the workpiece ( 5 ) has been completely inserted into the clamping space ( 54 ), the holding arms ( 47 , 48 ) automatically return to the locking position due to the forces of the springs ( 51 , 52 ) and press the workpiece ( 5 ) against the stop element ( 61 ). The workpiece ( 5 ) is thereby fixed within the plasma chamber ( 17 ).

After completion of the treatment of the workpiece ( 5 ), the workpiece ( 5 ) is gripped by a transfer element and pulled against the outlet bevels ( 68 ). The outlet bevel ( 68 ) is preferably curved and is designed with a curvature profile corresponding to an outer contour of the workpiece ( 5 ) in the contact area. The holding arms ( 47 , 48 ) are thereby brought apart again and release the workpiece ( 5 ). In particular, it is intended to provide the transfer element with controlled tong arms. The controlled pliers arms enable the workpieces ( 5 ) to be gripped actively and support the application of compressive and tensile forces to the insertion bevels ( 67 ) and the outlet bevels ( 68 ). In particular, it is contemplated that the controlled pliers of the transfer elements act on the workpiece ( 5 ) at a substantially same height level as the holding arms ( 47 , 48 ) or at a somewhat lower or higher level. As a result, the introduction of tilting forces into the workpiece ( 5 ) is avoided or greatly reduced.

Fig. 10 shows in the left part of the drawing the holding element ( 46 ) after inserting a bottle-like workpiece ( 5 ) which is acted upon by the holding arms ( 47 , 48 ) between a support ring ( 69 ) and a shoulder region ( 70 ).

Holding such a bottle-like workpiece ( 5 ) in the neck region shown leads to a very stable fixation of the workpiece ( 5 ).

According to the illustration in FIG. 11, the positioning element ( 28 ) carries a base element ( 71 ) in a plane below the base plate ( 42 ), which has a recess ( 72 ) for receiving a mouth area of the workpieces ( 5 ). A seal ( 73 ) is arranged in the recess ( 72 ), against which a boundary surface of the mouth region of the workpiece ( 5 ) can be guided.

The base plate ( 62 ) is arranged at a variable distance relative to the support plate ( 41 ). In order to implement the displaceable arrangement, the spacer elements ( 63 , 64 ) are displaceable or telescopic on the connecting elements ( 65 , 66 ). A basic positioning is specified by springs ( 74 , 75 ) which clamp the base plate ( 62 ) relative to the support plate ( 41 ).

In a basic positioning, a distance between the base plate ( 62 ) and the support plate ( 41 ) is predetermined such that the workpiece ( 5 ) can be inserted laterally into the holding element ( 46 ). After inserting the workpiece ( 5 ) in this way, the distance between the base plate ( 62 ) and the support plate ( 41 ) is reduced, so that the mouth region of the workpiece ( 5 ) is inserted into the recess ( 72 ). The reduction in distance between the base plate ( 62 ) and the support plate ( 41 ) is continued until the mouth region of the workpiece ( 5 ) is guided against the seal ( 73 ). In particular, it is intended to derive the change in position of the base plate ( 62 ) from the positioning movement of the chamber wall ( 18 ). For example, it is possible to guide a suitably shaped contact element of the chamber wall ( 18 ) against the base plate ( 62 ) and thereby to move the base plate ( 62 ) synchronously with the positioning movement of the chamber wall ( 18 ) in the direction of the support plate ( 41 ). When the chamber wall ( 18 ) moves in the opposite direction, the springs ( 74 , 75 ) push the base plate ( 62 ) back into the starting position.

FIG. 12 shows a cross section through the arrangement according to FIG. 11. In particular, the guidance of the sleeve-shaped spacer elements ( 63 , 64 ) along the bolt-shaped connecting elements ( 65 , 66 ) is illustrated. The base element ( 71 ) has a diameter configuration that tapers in the direction of the longitudinal axis of the cavity ( 53 ). As a result, self-centering is carried out when the workpiece ( 5 ) is lowered. In a lowered state of the workpiece ( 5 ), it is laterally fixed both by the holding arms ( 47 , 48 ) and by the base element ( 71 ). This ensures a tilt-proof arrangement of the workpiece ( 5 ) within the plasma station ( 3 ). The seal ( 73 ) is preferably realized from an elastic material. To avoid obstructing the positioning movement of the chamber wall ( 18 ), the seal ( 73 ) has a compensation space ( 76 ) below the movement range of the workpiece ( 5 ). This ensures both a sealing of the workpiece ( 5 ) and sufficient freedom of movement for the chamber wall ( 18 ).

A typical treatment process is explained below using the example of a coating process and carried out in such a way that the workpiece ( 5 ) is first transported to the plasma wheel ( 2 ) using the input wheel ( 11 ) and that the sleeve-like chamber wall ( 18 ) is inserted in a pushed-up state of the workpiece ( 5 ) into the plasma station ( 3 ). To insert the workpiece ( 5 ), the workpiece ( 5 ) is first inserted into the clamping space ( 54 ) by a transfer element. After the workpiece ( 5 ) has been fixed by the holding arms ( 47 , 48 ), the controlled holding pliers of the transfer element open and release the workpiece ( 5 ). After completion of the insertion process, the chamber wall ( 18 ) is lowered into its sealed position and moves the base plate ( 62 ) in the direction of the support plate ( 41 ) in the last part of its movement process. As a result, the mouth of the workpiece ( 5 ) is inserted into the recess ( 72 ) and sealed. Subsequently, both the cavity ( 4 ) and an interior of the workpiece ( 5 ) are simultaneously evacuated.

After sufficient evacuation of the interior of the cavity ( 4 ), the lance ( 36 ) is moved into the interior of the workpiece ( 5 ). It is also possible to move the lance ( 36 ) into the workpiece ( 5 ) synchronously with the beginning of the evacuation of the interior of the cavity. The pressure in the interior of the workpiece ( 5 ) is then further reduced. In addition, the positioning movement of the lance ( 36 ) is at least partially already carried out parallel to the positioning of the chamber wall ( 18 ). After reaching a sufficiently low vacuum, process gas is introduced into the interior of the workpiece ( 5 ) and the plasma is ignited with the aid of the microwave generator ( 19 ). In particular, it is intended to use the plasma to deposit both an adhesion promoter on an inner surface of the workpiece ( 5 ) and the actual barrier layer made of silicon oxides.

After the coating process has been completed, the lance ( 36 ) is removed from the interior of the workpiece ( 5 ) and the plasma chamber ( 17 ) and the interior of the workpiece ( 5 ) are ventilated. After reaching the ambient pressure within the cavity ( 4 ), the chamber wall ( 18 ) is raised again in order to remove the coated workpiece ( 5 ) and to enter a new workpiece ( 5 ) to be coated. To enable the workpiece ( 5 ) to be positioned laterally, the base plate ( 62 ) is raised again by the springs ( 74 , 75 ). To carry out the removal of the workpiece, a transfer element with a controlled pliers is again positioned in the area of the holding element ( 46 ) and the controlled pliers of the transfer element access the workpiece ( 5 ). The workpiece held in this way is then pulled out of the holding element ( 46 ), the holding arms ( 47 , 48 ) being pressed apart against the forces of the springs ( 51 , 52 ).

As an alternative to the described inner coating of workpieces ( 5 ), outer coatings, sterilizations or surface activations can also be carried out. In such embodiments, the holding element ( 46 ) in the case of bottle-like workpieces ( 5 ) grips the workpiece ( 5 ) preferably in the threaded region or at a short distance from the mouth opening.

The chamber wall ( 18 ), the sealing element ( 28 ) and / or the lance ( 36 ) can be positioned using different drive units. In principle, the use of pneumatic drives and / or electrical drives, in particular in one embodiment as a linear motor, is conceivable. In particular, however, it is contemplated to implement curve control to support exact movement coordination by rotating the plasma wheel ( 2 ). The curve control can be carried out, for example, in such a way that control cams are arranged along a circumference of the plasma wheel ( 2 ), along which curve rollers are guided. The cam rollers are coupled to the components to be positioned.

Claims (65)

1. A method for plasma treatment of workpieces, in which the workpiece is inserted into an at least partially evacuable chamber of a treatment station and in which the workpiece is positioned within the treatment station by a holding element, characterized in that the workpiece ( 5 ) by the holding element ( 46 ) is acted on in such a way that the workpiece ( 5 ) is guided in a position-changing manner in the direction of a longitudinal axis of the cavity ( 53 ) and is pressed against a seal ( 73 ) in a treatment position with a mouth region. 2. The method according to claim 1, characterized in that the workpiece ( 5 ) is acted upon by at least two clamping elements of the holding element ( 46 ) which can be positioned relative to one another such that the workpiece ( 5 ) is received by a clamping space ( 54 ) between the clamping elements. 3. The method according to claim 1 or 2, characterized characterized in that the positioning of the clamping elements is performed in a horizontal direction. 4. The method according to any one of claims 1 to 3, characterized in that the workpiece ( 5 ) of pliers-like holding arms ( 47 , 48 ) is positioned. 5. The method according to any one of claims 1 to 4, characterized in that an evacuation of a cavity ( 4 ) of the plasma station ( 3 ) through the chamber bottom ( 29 ) takes place. 6. The method according to any one of claims 1 to 5, characterized in that process gas is supplied through the chamber bottom ( 29 ). 7. The method according to any one of claims 1 to 6, characterized in that the process gas is fed through a lance ( 36 ) into an interior of the workpiece ( 5 ). 8. The method according to any one of claims 1 to 7, characterized in that the workpiece ( 5 ) of pivotally mounted holding arms ( 47 , 48 ) is positioned. 9. The method according to claim 8, characterized in that the holding arms ( 47 , 48 ) are pressed by springs into a locking position. 10. The method according to any one of claims 1 to 9, characterized in that the holding arms ( 47 , 48 ) are pressed apart when the workpiece ( 5 ) is inserted into the clamping space ( 54 ). 11. The method according to any one of claims 1 to 10, characterized in that the holding arms ( 47 , 48 ) are pressed apart when the workpiece ( 5 ) is pulled out of the clamping space ( 54 ). 12. The method according to any one of claims 1 to 11, characterized in that locking elements ( 59 , 60 ) for fixing the holding arms ( 47 , 48 ) are positioned together with the chamber wall ( 18 ). 13. The method according to any one of claims 1 to 12, characterized in that a stop element ( 61 ) for fixing the workpiece ( 5 ) is arranged approximately at the same height level as the holding arms ( 47 , 48 ). 14. The method according to any one of claims 1 to 13, characterized in that in the region of the chamber cover ( 31 ) from a microwave generator ( 19 ) generated microwaves are introduced into the cavity ( 4 ). 15. The method according to a greed claims 1 to 14, characterized in that a workpiece ( 5 ) is treated from a thermoplastic. 16. The method according to any one of claims 1 to 15, characterized in that an interior of a hollow workpiece ( 5 ) is treated. 17. The method according to any one of claims 1 to 16, characterized in that a container is treated as the workpiece ( 5 ). 18. The method according to any one of claims 1 to 17, characterized in that a beverage bottle is treated as the workpiece ( 5 ). 19. The method according to any one of claims 1 to 18, characterized in that the at least one plasma station ( 3 ) from a rotating plasma wheel ( 2 ) is transferred from an input position to an output position. 20. The method according to any one of claims 1 to 19, characterized in that a plurality of cavities ( 4 ) are provided by a plasma station ( 3 ). 21. The method according to any one of claims 1 to 20, characterized in that the workpiece ( 5 ) is fixed in a mouth region by the holding arms ( 47 , 48 ). 22. The method according to any one of claims 1 to 21, characterized characterized in that as a plasma treatment Plasma coating is carried out. 23. The method according to any one of claims 1 to 22, characterized characterized in that the plasma treatment under Using a low pressure plasma. 24. The method according to any one of claims 1 to 23, characterized characterized in that a plasma polymerization is carried out. 25. The method according to any one of claims 1 to 24, characterized characterized in that by the plasma at least Part of organic substances are separated. 26. The method according to any one of claims 1 to 25, characterized characterized in that by the plasma at least Part of inorganic substances are separated. 27. The method according to any one of claims 1 to 26, characterized in that a substance for improving the barrier properties of the workpiece ( 5 ) is deposited by the plasma. 28. The method according to claim 27, characterized in that in addition an adhesion promoter for improving an adherence of the substance is deposited on a surface of the workpiece ( 5 ). 29. The method according to any one of claims 1 to 28, characterized in that at least two workpieces ( 5 ) are treated simultaneously in a common cavity. 30. The method according to any one of claims 1 to 21, characterized characterized in that as a plasma treatment Plasma sterilization is carried out. 31. The method according to any one of claims 1 to 21, characterized in that a surface activation of the workpiece ( 5 ) is carried out as a plasma treatment. 32. The method according to any one of claims 1 to 31, characterized in that the holding element ( 46 ) is positioned by displacing a chamber wall ( 18 ) of the plasma station ( 3 ). 33. The method according to any one of claims 1 to 32, characterized in that the holding element ( 46 ) is held by at least one spring ( 74 , 75 ) in a basic position. 34.Device for plasma treatment of workpieces, which has at least one evacuable plasma chamber for receiving the workpieces and in which the plasma chamber is arranged in the region of a treatment station, and in which the plasma chamber is delimited by a chamber bottom, a chamber cover and a lateral chamber wall and at least one Holding element for positioning the workpiece, characterized in that the holding element ( 46 ) is arranged such that it can be changed in position at least in the direction of a longitudinal axis of the cavity ( 53 ) and that a base element ( 71 ) formed as part of the holding element ( 46 ) has a seal ( 73 ) for acting on a Mouth area of the workpiece ( 5 ). 35. Apparatus according to claim 34, characterized in that the holding element ( 46 ) has at least two clamping elements which can be positioned relative to one another and which are arranged relative to one another with a distance ( 54 ) providing a clamping space for receiving the workpiece ( 5 ). 36. Apparatus according to claim 34 or 35, characterized characterized in that the clamping elements in a horizontal direction can be positioned. 37. Apparatus according to claim 34 or 36, characterized in that the clamping elements are provided by holding arms ( 47 , 48 ) arranged in tongs. 38. Device according to one of claims 34 to 37, characterized in that at least one vacuum channel is arranged in the chamber base ( 29 ) for evacuating a cavity ( 4 ) of the plasma station ( 3 ). 39. Device according to one of claims 34 to 38, characterized in that at least one channel for supplying process gas is arranged in the chamber base ( 29 ). 40. Device according to one of claims 34 to 39, characterized in that for the supply of process gas in an interior of the workpiece ( 5 ) into a lance ( 36 ) is arranged positionable relative to the chamber bottom ( 29 ). 41. Device according to one of claims 34 to 40, characterized in that the holding arms ( 47 , 48 ) are arranged pivotably relative to axes of rotation ( 49 , 50 ). 42. Device according to one of claims 34 to 41, characterized in that the holding arms ( 47 , 48 ) are provided with a spring tension in the direction of a locking position. 43. Apparatus according to claim 42, characterized in that the spring tension of leg springs ( 51 , 52 ) are provided. 44. Device according to one of claims 34 to 43, characterized in that the holding arms ( 47 , 48 ) have fixing projections ( 55 , 56 ) which are each provided with an insertion bevel ( 67 ). 45. Device according to one of claims 34 to 44, characterized in that the holding arms ( 47 , 48 ) have fixing projections ( 55 , 56 ) which are each provided with an outlet bevel ( 68 ). 46. Device according to one of claims 34 to 45, characterized in that the holding arms ( 47 , 48 ) are provided in the region of their extension facing away from the fixing projections ( 55 , 56 ) with locking webs ( 57 , 58 ). 47. Device according to one of claims 34 to 46, characterized in that a microwave generator ( 19 ) is arranged in the region of the chamber cover ( 31 ). 48. Device according to one of claims 34 to 47, characterized in that the plasma station ( 3 ) for coating a workpiece ( 5 ) is made of a thermoplastic material. 49. Device according to one of claims 31 to 48, characterized in that the plasma station ( 3 ) is designed for coating a container-like workpiece ( 5 ). 50. Device according to one of claims 34 to 49, characterized in that the plasma station ( 3 ) is designed for coating an interior of a hollow-body-like workpiece ( 5 ). 51. Device according to one of claims 34 to 50, characterized in that the plasma station ( 3 ) for coating a workpiece ( 5 ) is designed in the form of a beverage bottle. 52. Device according to one of claims 34 to 51, characterized in that the at least one plasma station ( 3 ) is carried by a rotating plasma wheel ( 2 ). 53. Device according to one of claims 34 to 52, characterized in that several cavities ( 4 ) are arranged in the region of the plasma station ( 3 ). 54. Device according to one of claims 34 to 53, characterized in that a chamber wall ( 18 ) provided for providing at least two cavities ( 4 ) is arranged to be positionable. 55. Device according to one of claims 34 to 54, characterized in that the locking webs ( 57 , 58 ) of locking elements ( 59 , 60 ) can be fixed. 56. Apparatus according to claim 55, characterized in that the locking elements ( 59 , 60 ) are formed from a hardened material. 57. Apparatus according to claim 55 or 56, characterized in that the locking elements ( 59 , 60 ) from the chamber wall ( 18 ) can be positioned. 58. Device according to one of claims 34 to 57, characterized in that the holding element ( 46 ) is provided with a stop element ( 61 ) for the workpiece ( 5 ). 59. Device according to one of claims 34 to 58, characterized in that the fixing projections ( 55 , 56 ) and the stop element ( 61 ) are arranged at approximately the same height level. 60. Device according to one of claims 34 to 59, characterized in that the stop element ( 61 ) and the fixing projections ( 55 , 56 ) are arranged at a height level to act on a mouth region of a bottle-shaped workpiece ( 5 ). 61. Device according to one of claims 34 to 60, characterized in that the stop element ( 61 ) and the fixing projections ( 55 , 56 ) at a height for loading a bottle-shaped workpiece ( 5 ) between its support ring ( 69 ) and its shoulder area ( 70 ) are arranged. 62. Device according to one of claims 34 to 61, characterized in that the holding element ( 46 ) from a chamber wall ( 18 ) of the plasma station ( 3 ) can be positioned. 63. Device according to one of claims 34 to 62, characterized in that the holding element ( 46 ) has at least one spring ( 74 , 75 ) for positioning in an initial state. 64. Device according to one of claims 34 to 63, characterized in that the seal ( 73 ) is designed as a sealing ring. 65. Device according to one of claims 34 to 64, characterized in that the base element ( 71 ) is provided with a side guide for the workpiece ( 5 ).