Method and apparatus for producing containers from preforms made of a thermoplastic material with a high production rate

Abstract

The invention relates to a method and apparatuses for producing containers (2) from thermally conditioned preforms (1) made of a thermoplastic material, in particular PET, preferably using a stretch rod (11). The preforms (1) are heated in a heating device (24) while being circulated therethrough to a temperature suitable for the forming, in particular to a temperature above the glass transition temperature of the preform material, wherein a transfer device (35), which has a plurality of carrying devices (35') for the preforms, removes the preforms (1) from the heating device (24) at a first spacing (D1), i.e. the take-up spacing, guides them to a forming device (25), and transfers them to the forming device (25) at a second spacing (D2), i.e. the transfer spacing. The forming device (25) circulates the preforms (1) and, in the meantime, forms them by introducing a forming fluid under pressure into the container (2), the quotient (D2 / D1) of the transfer spacing and the take-up spacing being greater than 1 and less than 6.5, preferably less than 5.25, more preferably less than 5, and most preferably less than 4.

Description

Method and device for producing containers from preforms made of a thermoplastic material with high production output The invention relates to methods and devices for producing containers from preforms made of a thermoplastic material with high production output according to the preamble of claim 1 and claim 7 respectively. The invention also relates to methods and systems for producing filled, sealed and / or labeled containers. Preforms for the known processes and devices consist of a thermoplastic material, such as PET, PE, or PP, and are typically manufactured using injection molding. Before a preform can be formed into a container, it is thermally conditioned—in particular, heated and given a suitable temperature profile. The body of the preform is heated to approximately 100°C, for example. 120 °C and thus formable, while the mouth area may only reach significantly lower temperatures, since the preform is held and handled at the mouth area, e.g. on the support ring, and may not deform under the usual holding forces, because in the mouth area the preform already corresponds to the desired appearance of the container, in particular an external thread provided there for a screw cap. The production of containers from preforms made of a thermoplastic material is known, for example from preforms made of PET (polyethylene terephthalate), where the Preforms are formed into containers, e.g. by blow molding, and wherein the preforms are fed to different processing stations within a device for producing a container. Typically, a device for producing a container has a heating device for tempering or thermally conditioning the preforms, as well as a forming device with at least one forming station, in the area of ​​which the previously temperature-conditioned preform is expanded into a container. The expansion can take place, for example, with the aid of a compressed gas, in particular compressed air, as the pressure medium, which is introduced into the preform to be expanded at a forming pressure. According to a typical further processing, the containers produced by blow molding are fed to a downstream filling device and filled there with the intended product or filling material. It has also already been proposed to produce plastic containers, particularly in the form of bottles, from thermally conditioned or tempered preforms and to simultaneously fill them with a liquid 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, so that the respective preform is formed into the plastic container at the same time as filling. Such processes, in which the respective container is formed and filled simultaneously, can also be referred to as hydraulic forming processes or hydraulic container forming. Here, too, the preform is first temperature conditioned before the forming and filling process, i.e., heated to a temperature suitable for hydraulic forming and, if necessary, a temperature profile is imposed. When the containers are formed from the preforms by the filling material itself, i.e.Using the filling material as a hydraulic pressure medium, only one machine, a so-called form-fill machine, is required to form and fill the containers, although this machine is more complex. An example of such a machine is shown in US Pat. No. 7,914,726 B2. Another example is shown in DE 10 2010 007 541 A1. Continuously rotating rotary machines have proven particularly suitable for achieving high production figures, i.e., for achieving a high number of containers produced per unit of time, usually expressed as containers per hour (bottle per hour). In such rotary machines, for example, several forming stations are arranged on a rotating forming wheel, namely equidistantly on the circumference of the forming wheel. During the rotation of a station, the station is opened, a temperature-conditioned preform is fed into the station, the station closed, the forming process is carried out, the station is opened, and the finished container, possibly already filled with the filling material, is removed from the station and transported away by the continuously rotating forming wheel. This occurs periodically at the rotation frequency of the forming wheel, repeated for each of the several stations. The temperature conditioning of the preforms also takes place while they are being moved continuously through the heating device. It is known, for example, that a large number of transport mandrels, which clamp into the mouth opening of the preforms, are connected to one another in a chain-like manner and form an endless chain circulating in the heating device. In the inlet area of ​​the heating device, preforms are fed in, picked up by the transport mandrels and usually guided along stationary heaters which, for example, emit IR and / or NIR radiation and thereby introduce heat energy into the preforms. At the outlet of the heating device, the temperature-conditioned preforms are then taken over by a transfer device which takes over the further transport of the preforms to the forming device. This transfer device is also usually designed as a continuously rotating transfer wheel, on the outer circumference of which, for example,Several support devices, e.g., in the form of grippers, are arranged at intervals around the circumference. The preforms or containers are also usually transported in front of the heating device and behind the forming device using such continuously rotating transfer wheels. However, alternative transfer devices are also conceivable, e.g., based on planar motor drive systems, such as those known under the names Beckhoff XTS and XPianar, where they are referred to as movers and tiles. The heating device used, which heats the required large number of preforms per unit of time to the desired forming temperature, is operated in an energetically preferred manner with the smallest possible pitch between the preforms. This small pitch should preferably be provided in the area of ​​the radiant heaters that apply heat radiation to the preforms. In this area, the preforms should be lined up as closely as possible and passed past the radiant heaters so that the heat is transferred into the preforms with high efficiency. In contrast, the pitch on the forming wheel is significantly larger than the pitch in the heating device. The pitch on the forming wheel cannot be reduced arbitrarily, since the forming stations must be opened and closed and the forming stations must be able to reliably absorb the resulting forming forces.It should also be noted that a preform has a relatively small diameter, while the resulting... The formed container has a diameter several times greater than the diameter of the preforms, so that for this reason alone, the forming stations cannot be arranged as closely together as is the case with the transport mandrels in the area of ​​the heating device and the preforms held by them. For the reasons stated above, it is common and well-known that the pitch of the preforms in the heating device is different from the pitch of the preforms when they are inserted into the forming stations. In technical terms, this is referred to as a pitch distortion between these two devices. It is also known that the preforms are transferred from the heating device to the transfer device with a specific pitch, the pitch is increased during circulation on the transfer device, and then the preforms are transferred to the respective forming station with the increased pitch. The first pitch at the time of removal from the heating device can be referred to as the take-over pitch, and the second pitch at the time of transfer to the forming wheel can be referred to as the transfer pitch. It is known, for example, that several clamps are arranged circumferentially spaced apart on the outer circumference of a transfer wheel, each pivotable perpendicular to the radial direction of the transfer wheel, and the pitch change is achieved by pivoting the clamps in a tangential direction.As soon as a pair of grippers has taken a preform from the heating device, the grippers are pivoted so that it can be transferred to a forming station of the forming device with the pitch of the forming stations. After the preform has been transferred to the forming station, the grippers are pivoted again, this time so that the pitch of the heating device is reached again and another preform can be taken over. During rotation with the transfer wheel, the grippers change the pitch of the preforms they hold. Alternative designs are known which also allow the pitch to be changed during transport between the heating device and the forming device. The grippers mentioned here serve as an example. With the movers mentioned above (Beckhoff), the pitch could be changed by appropriately controlling the individual movers. In container manufacturing, there is a desire to increase the number of containers produced per unit of time. The material used, e.g., PET, should be as small as possible, so that the wall thicknesses of the containers and preforms can be further reduced. Current production outputs are limited by machines in which the forming process is performed by a gaseous forming fluid, is higher than with machines that use a liquid as the forming fluid. Irrespective of this, increased output and a lower use of PET material are always desired for both machines. An obvious option would be to increase the number of forming stations, while maintaining the same output per station, and for example to simply increase the radius of the forming wheel, thereby increasing the available circumference and arranging additional stations there. The output of the heating device could also be increased by enlarging the size. However, increasing output through enlargement also means that the materials used to build the machine, the masses to be moved, the space required, and the speeds, accelerations, and forces become ever larger, more problematic, and more difficult to control.This consequently also applies to further downstream treatment facilities for the containers, e.g. if, after the containers have been manufactured, they are to be labelled, filled and sealed, for example, because these treatment steps for the finished container would also have to follow the increased output of the forming device, in particular if a blocked arrangement is used, i.e. the said facilities are motion-coupled with one another, be it mechanically or by control technology. The invention is therefore based on the object of providing an improved solution that addresses these problems. In particular, the object of the invention is to provide a solution that allows the number of containers produced per unit of time to be increased while still allowing a moderate and manageable increase in the amount of material required to construct the machine, the masses to be moved, the required space, and the speeds, accelerations, and forces. According to a first aspect of the invention, this object is achieved by a method having the features of claim 1. According to a second aspect of the invention, this object is achieved by a device having the features of claim 7. Preferred embodiments are mentioned in the respective subclaims. The first aspect of the invention relates to methods for producing containers, as set out in the above introduction to the prior art, i.e., containers are produced from thermally conditioned preforms made of a thermoplastic material, in particular PET. This is preferably carried out using a stretching rod, which is also generally known in the prior art. The preforms are, for the purpose of their thermal conditioning, heated in a heating device, by means of which the preforms are moved through in a rotating manner, and during the movement are brought to a temperature suitable for forming. A suitable temperature is, in particular, a temperature above the glass transition temperature of the preform material. Such heating devices are also known in the prior art in many different forms. Transport through the heating device can, for example, be carried out by chain-like transport mandrels that engage in the mouth area of ​​the preforms and guide the preforms along stationary heating boxes with radiant heaters. After temperature conditioning has been completed, the preforms are removed from the heating device by a transfer device, which has several carrying devices for the preforms, at a first pitch, the take-over pitch. This take-over pitch is the distance between adjacent preforms at the take-over point of the transfer device, i.e.The preform currently located at the transfer point and its immediately following neighbor, or the distance between these two preforms, are considered. The distance is defined as the distance between the longitudinal axes of the two neighboring preforms under consideration. In the case of transport mandrels that guide these preforms through the heating device, the position of the longitudinal axis of the preform generally also corresponds to the position of the longitudinal axis of the transport mandrel, so that this transfer pitch also corresponds to the distance between the two transport mandrels under consideration in the sense of the distance between the longitudinal axes of the two transport mandrels under consideration. This distance is the claimed transfer pitch. This distance is always the same at the transfer point of the transfer device. However, the distance between neighboring preforms can deviate from this in other areas of the heating device.A typical and preferred example will be given later. The transfer device in question guides the preforms taken over to a forming device and transfers the preforms to the forming device with a second pitch, the transfer pitch. Analogous to the transfer pitch, the transfer pitch also considers the preform at the transfer point to the forming device and its distance to the adjacent preform, in this case the distance to the immediately preceding preform. Here, too, the distance is based on the distance between the longitudinal axes of the two adjacent preforms. The position of this longitudinal axis of the preforms usually coincides with the position of the longitudinal axis of the stretching rod, where advantageously provided, the position of the longitudinal axis of a blowing nozzle or the external mold of the forming station, so that this distance of the corresponding Longitudinal axes could be adjusted. In typical forming equipment, this distance between the longitudinal axes is fixed, so that, unlike heating equipment, the pitch of the preforms (or, after forming, the pitch of the containers) remains unchanged throughout the entire rotation in the forming equipment. The forming equipment moves the preforms in a rotating motion. During the rotating motion, the preform is formed by introducing a forming fluid under pressure into the container. It should be added that when the preform moves on a curved path, the distance along this curved path is considered the pitch. As the preform circulates on the transfer device, its pitch must be changed. The transfer device receives the preform at the take-over pitch and transfers it to the forming device at a transfer pitch. For the reasons stated in the introduction to the description, these two pitches are not identical; rather, the transfer pitch is generally several times larger than the take-over pitch. The difference in these two pitches must be compensated for accordingly between the take-over point and the transfer point, i.e., the preform must be accelerated on the circulation path between these two points. The term acceleration includes positive and negative acceleration, with positive acceleration generally being required because the pitch must be increased.This acceleration required to adjust the spacing between the preforms simultaneously places a load on the already temperature-conditioned preforms, which are deformable due to the temperature conditioning and can therefore, for example, bend at high accelerations, with negative consequences for the subsequent forming steps. According to the invention, it is therefore provided that the quotient of the transfer pitch and the take-over pitch is greater than 1 and less than 6, preferably less than 5.5, more preferably less than 5, and finally preferably less than 4. The specified limitation of the quotient results in the pitch compensation to be carried out remaining low and thus the acceleration load on the preforms deformable due to temperature conditioning remaining at a low level whose effect on the preforms is acceptable, while high production outputs can still be achieved.It should be noted that this acceleration, due to the required pitch compensation, is in addition to the acceleration already occurring due to movement on a curved orbit. The fact that the quotient is greater than 1 results from the fact that the pitch spacing on the transfer wheel must be increased. The quotients mentioned mean, for example, in a concrete example, that for a forming wheel with 36 forming stations and a blow wheel diameter of 3.08 m, the pitch on the forming wheel is approximately 270 mm. A transfer device with, for example, 22 support devices could, for example, start from a transfer pitch of approximately 50 mm and compensate for the pitch to 270 mm. The required quotient in this case is, for example, 5.4. This quotient can be further reduced either by reducing the pitch on the forming wheel or by increasing the pitch at the removal point of the heating device. In this example, the support ring diameter on the preform or container can be up to 36 mm, for example, and the bottle size can be up to 2 liters, for example. The blowing wheel radius is the radius of the path along which the preforms move during their rotation on the blowing wheel, more precisely the path along which the longitudinal axis of the preform moves, or even more precisely the longitudinal axis of the neck sections, which coincides with the longitudinal axis of the preform. This is usually also the path along which the main axes of the forming stations move. Similarly, the radius of the transfer device is defined by the path radius of the path along which the preforms or their longitudinal axes move. The radius of other devices is also defined in relation to the movement path of the preforms or containers. The above example is also a preferred example with regard to the number of forming stations, whereby it is generally preferred that the number of stations arranged equidistantly around the circumference of the forming wheel is greater than 24, more preferably greater than 30, and finally greater than or equal to 36. These numbers lead to a favorable ratio of achievable production output to the required mass and space requirements, as well as the resulting forces, accelerations, and loads. Alternatively or additionally, it is preferred that the forming wheel diameter is greater than 2.5 m, preferably greater than 3 m, more preferably less than 3.36 m, more preferably less than 3.25 m. These specified upper and lower limits for diameters, which can be combined with each other, also represent a favorable compromise between achievable production output (the larger the radius, the more stations can be arranged) and expenditure (the larger the radius, the more construction material has to be used and the more space is required) and the resulting forces, accelerations and loads (the larger the radius, the higher the radial acceleration and the loads, e.g. on bearings, brake and Drive systems). The forming wheel radius is defined in relation to the circle traversed by the vertically oriented longitudinal axis of the preforms held in the stations or of the containers produced therefrom, which, as explained above, generally coincides with the circular path on which the vertically positioned longitudinal axes of the stretching rod, the blowing nozzle or the station's main axis move during the rotation of the forming wheel. To achieve a high achievable production output, it is preferred that the output per station be greater than 2555 bottles per hour. Particularly in conjunction with the preferred station numbers specified above, the preferred radii specified above, and the preferred peripheral speed specified below, these output rates still result in sufficient cycle times and time available for forming to enable the preform to be formed into the container without any loss of quality. In particular, it is alternatively or additionally preferred that the peripheral speed of the preform or container on the forming wheel be less than 7.5 m / s. This, too, represents a compromise between the desired high production volume and the careful handling of the preforms and machine components. Alternatively or in addition to the aforementioned features, it is advantageous for the diameter of the transfer device to be less than or equal to 1600 mm. While a larger diameter would increase the path for pitch compensation, this would, among other things, be at the expense of space requirements. The stated diameter proves to be sufficient to accommodate the required number of support devices and, at the resulting rotational speed, to perform the required pitch compensation without placing excessive strain on the preforms. For the same optimization reasons, it is alternatively or additionally advantageous for the number of forming stations to be less than 1.65 times the number of support devices on the transfer device. In the preferred embodiment described above, there were 36 forming stations and 22 support devices, so the ratio is slightly below 1.65. Increasing the number to 24 support devices reduces this ratio to 1.5, for example. The combination of some or all of the features described above as advantageous leads to an overall result that is considered optimal. For high production output, it has also proven advantageous for the preforms to be transported in two rows along radiant heaters in the heating device, and in one row in the area of ​​removal from the heating device and in the area of ​​transfer to the heating device. Suitable transport devices and heating boxes with radiant heaters that enable this are known in the art, e.g., from EP 3 452 265 A1 or EP 3 284 579 A1. This has also proven advantageous in terms of space requirements and energy efficiency during the heating process, and it also allows the transfer pitch to be increased, e.g., from approximately 50 mm to approximately 65 mm, while the pitch in the area of ​​the radiant heaters, for example, is less than 20 mm. With a view to reducing the pitch distance on the forming wheel, it is proposed that the forming stations have, in a manner known per se, multi-part outer molds which can be opened and closed, and against whose inner contour the preforms are expanded to form the container. The outer mold consists of two side shells, the inner contour of which defines the lateral outer contour of the container formed therein, and of a base mold, the inner contour of which defines the outer contour of the container in its base region. It is advantageous for reducing the pitch distance if one of the two side shells is arranged immobilely on the forming wheel, while the other side shell is movable relative to the first side shell. To reduce wear and mechanical stress, the movement of the side shell and the movement of the base shell are preferably mechanically coupled.In this way, an otherwise necessary additional drive device is omitted because, for example, the driven movement of the side shells can be transferred to the base shell by the mechanical movement coupling, so that no separate drive device is required for the base shell. Further preferably, the stretch rod is driven by a linear motor, so that, for example, no control cam needs to be used for the stretch rod movement, which would be subject to high stress, especially with the high desired production outputs. For the same reason, namely to avoid an external control cam, the opening and closing of the mold is preferably also driven by an electric motor. In particular, it is preferred that the driving of the stretch rod and the driving of the opening and closing movement of the mold are carried out by a single common drive. by a linear motor. This means that only one drive, e.g., an electric drive, is required to execute the essential movements of the forming station, which, on the one hand, eliminates the need for external control cams and, on the other, reduces the number of required drives. This also contributes to reducing the moving mass and promotes high production output. With regard to the support devices of the transfer device, it is advantageously proposed that these be designed as pivoting gripper arms. This means that the arms are pivoting, with gripper-like grippers arranged at their radially outer ends. The change in pitch from the receiving pitch to the transfer pitch can then be implemented, for example, by a pivoting movement of the gripper arms. This can be achieved, for example, by cam control, but a corresponding drive, such as an electrically operated actuator, can also be arranged on the transfer device. Finally, in this first aspect of the invention, it is advantageously proposed that, after their forming production, the containers are filled in a filling device and / or sealed in a closing device and / or labeled in a labeling device, with these devices being arranged in a block arrangement with the forming device. In this way, the described optimization can also be utilized for the subsequent processing steps of filling, closing, and / or labeling, and an overall system can be constructed that requires very little space overall. The second aspect of the invention relates to an apparatus for producing containers from thermally conditioned preforms made of a thermoplastic material. The corresponding apparatus features and the preferred embodiments explained therein in the subclaims essentially follow the features explained above for the first aspect of the invention. The apparatus according to the second aspect of the invention is suitable and intended for carrying out the method addressed in the first aspect of the invention and has the necessary physical means for this purpose, as stated in claim 7 and as stated in claims 8-12 for preferred embodiments. The device comprises a heating device with a transport device that guides preforms through the heating device. This heating device takes over the temperature conditioning of the preforms by being controlled and designed to transport the preforms on their way through the heating device to a position suitable for forming. to heat to a suitable temperature, in particular to a temperature above the glass transition temperature of the preform material. As already explained with regard to the method, the device comprises a transfer device with a plurality of carrying devices, which is arranged and designed to remove the preforms from the heating device at a first pitch, the transfer pitch, to guide them to a forming device, and to transfer them to the forming device at a second pitch, the transfer pitch. Accordingly, during the conveying to the forming device, the pitch is transferred from the transfer pitch to the transfer pitch.The forming device is designed as a forming wheel driven by rotation for continuous rotation, and is arranged and configured to move preforms transferred to the forming wheel in a rotating manner and to form the preform into the container during the rotation by introducing a forming fluid under pressure. The device according to the invention preferably has a stretching rod. According to the invention and for the reasons stated in the first aspect of the invention, the quotient of the transfer pitch and the receiving pitch is greater than 1 and less than 6, preferably less than 5.25, further preferably less than 5, and finally preferably less than 4. For the further features and advantages in the device subclaims 8 to 12, reference can be made to the statements on the method subclaims 2 to 6. Preferred embodiments are explained below by way of example with reference to the accompanying figures. In the figures, identical or essentially functionally identical or similar elements are designated by the same reference numerals. They show: Fig. 1 : a longitudinal section through an outer mold of a forming station in which a preform is stretched and expanded, Fig. 2: a schematic diagram illustrating a basic structure of a container manufacturing machine; Fig. 3: a schematic representation for implementing a change between single-row and double-row transport of preforms on a transport path through a heating device; Fig. 4a, b, c: perspective views of an embodiment of a forming station in different positions with several movement-coupled station elements: a) initial position, b) intermediate position and c) end position; Fig. 5 a, b: Schematic diagrams of a first exemplary transport device of a heating device for changing between a single-row and a double-row transport mode; Fig. 6 a, b, c: Schematic diagrams of a second exemplary transport device of a heating device for changing between a single-row and a double-row transport mode; Fig. 7a, b: Principle representations of the opening and closing movement of the mold carriers of an exemplary forming station. The basic structure of a forming station 3 known from the prior art for forming preforms 1 into containers 2 is shown in Fig. 1. Illustrations of a more detailed example will follow later in Figs. 4a, 4b, 4c. The invention extends both to the use of a gaseous forming medium under a forming pressure, e.g. compressed air, and to the use of a liquid forming medium under forming pressure, e.g. the filling material to be filled into the container. Nevertheless, the use of a gaseous forming medium will be primarily considered and described below, because such devices and methods achieve higher production figures, so that the present invention is particularly directed to these devices and methods. In this respect, without limiting the generality, the terms blow molding processes, blow molding devices, blow molding wheels, etc. will be referred to below as representatives of both forming media. The forming station or blow molding station 3 for forming the container 2 essentially consists of an outer blow mold 4 into which a preform 1 can be inserted. The preform 1 can be an injection-molded part made of polyethylene terephthalate (PET). To enable the preform 1 to be inserted into the blow mold 4 and to enable the finished container 2 to be removed, the blow mold 4 consists of mold halves 5, 6, which are also referred to as side shells, and a base part 7, which can be positioned by a lifting device (not shown). The preform 1 can be held in the area of ​​the blow molding station 3 by a transport mandrel 9, which, together with the preform 1 passes through a plurality of treatment stations within the container manufacturing device. However, it is also possible to insert the preform 1 directly into the blow mold 4, for example, using tongs or other handling means. To enable a compressed air supply, for example, a connecting piston 10 (not shown) is arranged above the transport mandrel 9, which is also referred to as a blowing nozzle and supplies compressed air to the preform 1 and simultaneously seals it relative to the transport mandrel 9. In a modified design, however, it is also conceivable in principle to use fixed compressed air supply lines. In this embodiment, the preform 1 is stretched with the aid of a stretching rod 11, which is positioned in a manner not shown by a drive device. An example of a drive device in the form of an electric drive, a linear motor, is given in Figures 4a, b, c. According to another embodiment, however, the stretching rod 11 can also be positioned mechanically via curve segments that are acted upon by pick-up rollers. The use of curve segments is generally expedient and common in the prior art when a plurality of blow molding stations 3 are arranged on a rotating blow molding wheel 25. Although the use of a stretching rod entails additional technical effort, it offers advantages in the production of high-quality containers with consistent quality. When the stretching rod is used, it is moved into the area of ​​a base 14 of the preform 1.During the actual stretching process, the stretching rod is positioned as desired, e.g., by a linear motor (alternatively, by a servo motor with a threaded spindle, a rack and pinion, a toothed belt, etc.) and, e.g., according to a predefined characteristic curve, or, e.g., via a cam control system. A guide roller, which slides along the curved path during the stretching process and is mechanically coupled to the stretching rod, specifies the current stretching position. The use of a stretching rod is considered preferred. Likewise, an electric motor drive for the stretching rod is considered preferred. For the purpose of interchangeability of the mold halves 5, 6, namely in order to be able to produce different containers 2 in the container production device, these are arranged, for example, detachably on supports 19, 20, whereby these supports 19, 20 are decisive for the absorption of forces. The bottom shell 7 is also detachably arranged on a bottom mold support (not shown) for the purpose of its interchangeability. Corresponding arrangements of supports and mold shells are known in many different ways in the prior art. For the insertion of a preform 1 into the blow mold 4 and for the removal of the completely formed containers 2, it is known, for example, that these supports 19, 20 are folded open like a book. Other opening and closing movements are also known. However, the figures depict a book-like opening. After the mold halves 5, 6 arranged in the region of supports 19, 20 are closed, the supports 19, 20 are locked relative to one another by means of a locking device. To adapt to different shapes of a mouth section 21 of the preform 1, the use of separate threaded inserts 22 in the area of ​​the blow mold 4 is provided according to Fig. 1. In addition to the blown container 2, Fig. 1 also shows the preform 1 in dashed lines and a schematic representation of a developing container bubble 23. Fig. 2 shows a schematic of the basic structure of a blow molding machine equipped with a heating device 24 and a rotating blowing wheel 25 as a forming device. Starting from a preform input 26, the preforms 1 are transported by transfer wheels 27, 28, 29 into the area of ​​the heating device 24. Radiant heaters 30 and optionally fans 31 are arranged along rectilinear heating sections in the heating device 24 to temperature-control the preforms 1. After the preforms 1 have been sufficiently temperature-controlled, also referred to as temperature conditioning, they are transferred to the blowing wheel 25, in the area of ​​which the blowing stations 3 are arranged. The finished blow-molded containers 2 are fed by further transfer wheels to an output section 32. The output section could be followed by a filler and / or labeler and / or closer. During production, the blowing wheel 25 rotates continuously at a constant rotational speed. During one rotation, a preform 1 is inserted into a blowing station 3, and the preform 1 is expanded into a container 2 and the removal of the formed container 2 from the blow molding station 3. The blow molding stations 3 may have a stretching rod 11, which can be inserted into the preform 1 to support the axial stretching and guidance. If the blowing station 3 has a stretching rod, the preform 1 is also stretched during one revolution of the blowing wheel 25. In the example shown, the expansion of the preform 1 is achieved by supplying compressed air. The compressed air supply is divided into a pre-blowing phase, in which gas, for example compressed air, is supplied at a low pressure level, and a subsequent main blowing phase, in which gas is supplied at a higher pressure level. During the pre-blowing phase, compressed air with a pressure in the range of 10 bar to 25 bar is typically used, and during the main blowing phase, compressed air with a pressure in the interval from 25 bar to 40 bar. A typical implementation of the blow molding process after inserting the preform 1 into the blow mold 4 and after locking the blow molding station 3 is initially carried out by moving the stretch rod 11 into the preform 1 with simultaneous blow molding pressure support in such a way that the preform 1 does not shrink radially onto the stretch rod 11 due to the axial stretching. After the stretching process has been fully carried out as shown in Fig. 1, the container bladder 23 expands completely into the final contour of the container 2 and the maximum internal pressure is maintained until the container 2 has achieved sufficient dimensional stability through cooling. After this dimensional stability has been achieved, the blow molding pressure supply is switched off and the stretch rod 11 is withdrawn from the blow mold 4 and thus from the blown container 2. It can also be seen from Fig. 2 that, in the embodiment shown, the heating device 24 has a transport device formed from a plurality of rotating transport elements 33 that are arranged in a chain-like manner and guided along deflection wheels 34. These transport elements 33 can, for example, each be designed as a transport mandrel that engages on the inside in the mouth section 21 of a preform 1 and holds the preform in a clamping manner and guides it along the stationary heating radiators 30 or the cooling fan 31. As a rule, it is also provided that the preforms are driven to rotate about their longitudinal axis in order to achieve uniform heating in the circumferential direction.In the illustrated embodiment, a single, relatively large deflection wheel 34 is used in the area of ​​the extension of the heating device 24 facing the transfer wheel 29 and an input wheel 35, and two comparatively smaller deflection wheels 36 are used in the area of ​​adjacent deflections. In principle, however, any other guides are also conceivable. As an alternative to the use of chain-like transport elements 33, it is also possible, for example, to use a rotating heating wheel. After the containers 2 have been blown, they are removed from the area of ​​the blowing stations 3 by a removal wheel 37 and transported to the output line 32 via the transfer wheel 28 and an output wheel 38. Further processing stations such as fillers, labelers, closers, etc. can follow downstream, possibly in a block design. During production, the wheels and transport elements shown rotate at a continuous speed. The respective rotation of the individual Wheels and the transport elements are coordinated with one another, e.g. mechanically, e.g. by synchronizing the respective controls of the rotary drives and / or the rotational positions of the wheels. This ensures that the transfer and removal of the preforms 1 and the transfer and removal of the finished containers 2 can take place collision-free and without disruption and that the required process times, on the one hand for the temperature conditioning of the preforms 1 in the heating device 24 and on the other hand for the forming of the aforementioned preforms 1 into containers 2 on the forming wheel 25, are reproducibly and consistently maintained. The execution of cam-controlled or motor-driven movements leads to the reproducibility of these movements over time, so that overall a consistently good container quality is produced in a reproducible manner. From Figure 2 it can be seen that the distance between the preforms 1 in the heating device 24 is significantly smaller than the distance on the blowing wheel 25. The input wheel designated by reference numeral 35 removes the preforms with a pitch Di from the heating device 24 and transfers these preforms with a different pitch D2 to the blowing wheel. It is shown that the input wheel 35 has pivoting gripper arms 35' in order to compensate for this pitch difference on the way from the heating device 24 to the blowing wheel 25. As a result, the preform 1 held at the end of such a gripper arm 35', e.g. by a pair of tongs arranged there, not only experiences acceleration due to the circular movement, but also experiences further acceleration due to the compensating movement of the arm.The corresponding forces on a preform are greater the higher the number of containers produced per unit of time, since the corresponding wheels must rotate faster or have a larger radius. The illustrated input wheel 35 is an example of a transfer device within the meaning of the claims. The tongs cited as an example are an example of a carrying device within the meaning of the claims. The pitch Di, referred to in the claims as the transfer pitch, corresponds in Figure 2 to the distance between the preform currently being removed by a gripper arm 35' and the next adjacent preform to be removed by the next gripper arm. With a straight guide, this pitch Di is the straight-line distance; with a guide on a circular path, this distance Di is the intermediate circular path section. The transfer pitch D2 within the meaning of the claims corresponds in the example in Figure 2 to the distance between the preforms in adjacent forming stations. This distance D2 is constant in the example shown because the forming stations are arranged at a fixed distance, circumferentially distributed, and equidistant from the blowing wheel 25.Since there is an arrangement on a rotating blowing wheel,. This pitch D2 is the distance in the circumferential direction, i.e. following the curved path, and thus corresponds to the arc length between the preforms in two adjacent forming stations. The transport device 24 in Figure 2 is shown as a single-row arrangement of the chain links of a chain. It is fundamentally possible and also known that, particularly in the area of ​​the radiant heaters 30, i.e., in the area of ​​straight heating sections, the guidance of the preforms 1 takes place in a two-row transport manner, as is indicated in Figure 3 for the transport sections 305, while in the curved transport areas 304, a single-row transport is provided. Single-row means that all preforms 1 are arranged one behind the other in the conveying direction R, while a two-row arrangement means that the preforms 1 are also arranged next to one another in the conveying direction R, i.e.There is a first row with preforms 1 arranged one behind the other in the conveying direction R (distance D3, which is not the transfer pitch) and a second row with preforms 1 also arranged one behind the other (also distance D3, which is not the transfer pitch), wherein there is a distance between the preforms 1 of the first and the second row, so that the two rows and their preforms 1 are arranged next to one another in the conveying direction R. Overall, this leads to, on the one hand, the required installation space for the heating device 24 being reduced, and, on the other hand, the heating power provided by the heating radiators 30, which are arranged in the area of ​​the two-row guide 305 of the preforms 1, being very effectively converted into heating of the preforms 1.Corresponding transport devices that allow a change from a single-row guidance of the preforms 1 to a double-row guidance of the preforms 1, as shown in Figure 3, are known in the prior art, e.g., from EP 3 452 265 A1 or EP 3 284 579 A1, and are presented below by way of example with reference to Figures 5a and 5b, as well as 6a, 6b, and 6c. This described change in the number of rows during guidance must be distinguished from cases in which each transport element carries two or more preforms, but no change in the number of rows occurs. Figures 1-3 serve only to explain the terms used in the claims and to explain the technical background. A statement about the quotient of the transfer pitch Ü2 and the takeover pitch Di cannot be derived from these figures. According to the invention, this quotient (D2 / Di) should be greater than 1 and, for example, less than 6.5, preferably less than 5.5, more preferably less than 5, and finally preferably less than 4. When providing a Such a quotient reduces the acceleration force which occurs during the required pitch compensation on the input wheel 35. The radii mentioned in the claims or the number of forming stations or support devices according to the claims cannot be inferred from these schematic representations in Figs. 1-3. In an implementation according to the claims, for example, 36 forming stations would be arranged on the blowing wheel 25 and the input wheel 35 would have, for example, 24 gripper arms, so that this would result in a quotient (number of forming stations / number of support devices) of 1.5. The pitch distance could be increased during rotation on the input wheel 35, for example, from originally 6 cm (Di) to finally 30 cm (D2). Figures 4a to 4c show, by way of example, a blow molding station 3, which is shown in considerably more detail than the blow molding station shown in Fig. 1. In particular, this illustration shows that the stretching rod 11 is held by a stretching rod support 41, and a linear motor 50 is arranged at the upper end of the stretching rod, driving the stretching rod 11 in a lifting movement. The linear motor drive is considered preferable to a cam-controlled drive, especially with regard to high production outputs. The figures also show the arrangement of the pneumatic block 46 for supplying blowing pressure to the blowing station 3. The pneumatic block 46 is equipped with high-pressure valves that can be connected to one or more pressure supplies via ports. After the containers 2 have been blown, the blowing air to be discharged into the environment is first fed to a silencer via the pneumatic block 46. Figs. 4a to 4c show different positions of the positionable parts of the blow molding station 3 at different times during the blow molding process described above. Generally and generally, it is preferable to perform several movements of the blow molding station in a motion-coupled manner, preferably more than two movements from the group: a) moving the stretching rod, b) moving the side shells; c) moving the base mold, d) moving the blow nozzle. Fig. 4a shows the initial position, the blow molding station 3 is in an open state. In this position, a thermally conditioned preform 1 can be inserted into the blow mold 4 to be subsequently formed into a container 2. Driven by the linear motor 50, a drive rod 51 pushes the stretch rod carrier 41 and the stretch rod 11 held by the carrier 41 downwards in a vertical direction. The stretch rod 11 has a guide carriage 52 on one or both sides, which slides on guide elements. A corresponding arrangement is described, for example, in DE 10 2009 006 508 A1 in shown in Figures 5 to 8 there, and in the description there in paragraphs

[0056] until

[0084] explained. These illustrations and this description are explicitly referenced here and, to avoid repetition of the content, are included here by this reference. As shown in Fig. 7 of DE 10 2009 006 508 A1, the pneumatic block 46 can be designed, for example, as a so-called blowing nozzle 10, which is provided for supplying compressed air into the interior of the container 2 to be blown. The pneumatic block 46 is connected to a blowing gas supply via supply lines (not shown) and serves as a blowing gas supply arranged so as to be positionable relative to the blow mold 4. The positionability is necessary so that after inserting a preform 1 into the blow mold 4, a pressure-tight connection can be established between the pneumatic block 46 and the blow mold 4 or between the pneumatic block 46 and the preform 1 or the container 2 to be blown by a lifting movement. As further shown in Figs. 7 and 8 of DE 10 2009 006 508 A1 and in the paragraphs therein

[0077] until

[0084] As explained above, the pneumatic block 46 is coupled to the stretch rod movement via joints, levers, and other positioning and adjusting means. It is considered advantageous, especially with a view to high production numbers, to provide such a coupling between the stretch rod and blow nozzle movements. According to the operating state shown in Fig. 4b, in which the linear motor 50 has moved the stretch rod carrier 41 downward by a certain distance, the pneumatic block 46 is lowered and guided in a sealed manner against the blow mold 4 or the preform 1. In this operating state, blow air can be supplied into the preform. In this operating state, the stretch rod 11 has not yet advanced to the bottom 14 of the preform 1. The lowering movement of the stretch rod 11 from the starting position in Fig. 4a to the intermediate position in Fig. 4b is preferably also transmitted to the mold halves 19, 20 and to the bottom mold 7 - this is also considered advantageous with regard to high production numbers. For this purpose, in the example shown, the stretch rod carrier 41 has a coupling element 54, on which a driver 65 is arranged laterally. This driver 65 slides along a driving profile 64 which is defined by a control cam block 60.This control cam block 60, in turn, is firmly connected to a control shaft 61, which runs laterally of the blowing station 3 and parallel to the stretching rod 11. The control shaft 61 is rotatably mounted in an upper and a lower bearing 66, and these bearings 66 are firmly connected to the blowing station 3 and to the support structure of the blowing station 3, respectively. In the starting position in Fig. 4a, the driver 65 is located at the upper end of the driver profile 64. When the stretch rod support 41 is lowered, the driver 65 also moves downwards and thereby forces the control shaft 61 carrying the control cam block 60 to rotate. In the position shown in Fig. 4b, the driver 65 has reached the end of the driver profile 64. Further lowering of the stretch rod support 41 does not result in any further rotation of the control shaft 61 because the driver 65 continues to run outside the control cam block 60. In the phase between the starting position and reaching the intermediate position, the blow mold halves 19, 20 are closed and the base mold 7 is raised. When the stretch rod 11 is raised from the end position in Fig. 4c back to the starting position in Fig. 4a via the position shown in Fig.In the intermediate position shown in Figure 4b, the driver 65 is first inserted into the insertion opening of the driver profile 64 and then slides along the driver profile 64. Once again, the driver 65 guided in the driver profile 64 causes a pivoting movement of the control shaft 61. This pivoting movement leads to an opening of the blow mold halves 19, 20 and to a lowering of the base mold 7. The blow mold halves 19, 20 are arranged so as to be pivotable relative to a station axis of the blow molding station 3. The blow mold halves 19, 20 are coupled to the control shaft 61 via actuating arms 70. The rotary movement of the control shaft 61 is transformed into an opening and closing of the mold carriers (19, 20), as shown, for example, in Fig. 5 of DE 10 2004 045 405 A1 and in the paragraphs therein.

[0047] until

[0052] To avoid repetition, explicit reference is also made to this Figure 5 and to these descriptive passages and their content. It is not shown how the bottom mold movement is also coupled to the rotation of the control shaft 61. For this purpose, reference is made to EP 2 917 019 B2 and Figures 5a and 5b therein, as well as to the corresponding description in

[0063] -

[0066] To avoid repetition, explicit reference is also made to these figures and to these descriptive passages and their content. To carry out a new blow molding, after inserting a new preform 1 into the blow mold 4, the stretch rod 11 is lowered again and thus also the pneumatic block 46 is lowered, the blow mold halves 19, 20 are closed and the base mold 7 is raised. The mechanical coupling described is to be regarded merely as an example of how the movement of the blow mold (side shells and / or base mold) can be coupled to the movement of the stretch rod and / or the blow nozzle, which is generally considered preferable for achieving high production numbers. Figures 5a and 5b show a first embodiment of a transport device for transporting the preforms through a heating device along a transport path T, wherein on this transport path T a change between single-row and double-row transport takes place, as shown schematically in Fig. 3. The transport device is designed as a conveyor chain. The transport direction R is indicated by arrows. In the areas 54 a single-row transport of the preforms 1 takes place and in the areas 55 a double-row transport of the preforms 1 takes place. By changing between the closed position 50 in the straight path sections and the spread position 51 in the curved path sections, the preform guidance changes accordingly between a single-row transport 54 in the curves and a double-row transport 55 on the straight paths. Fig. 5a shows a partial section of a suitable conveyor chain in a top view. As can be clearly seen in this figure, the section of the conveyor chain shown is in a transition from a straight guide to a curved guide. In the curved guide of the chain links 33, adjacent main arms 42 are in a spread position 51. In the straight guide of the chain links 33, the adjacent main arms 42 are in the closed position 50. The pivot arms 43 or their pivot arm ends with transport mandrel 39' are in a deflected position 53 radially outward, while the extension arms 41 are moved into the closed position 50, and the pivot arms 43 or their pivot arm ends with transport mandrel 39' are in a deflected position 52, while the extension arms 41 are moved into the spread position 51. During the transition from the deflected position 53 to the deflected position 52, the pivot arms 43 are pivoted relative to the main arms 42 such that the handling means 39, 39' transition from a two-row guide to a single-row guide. As a result, the preforms 1 (not shown) carried on the handling means 39, 39' are transferred from a two-row to a single-row transport and the pitch distance D3 is increased in Di.Analogously, the handling means 39, 39' are transferred from a single-row guide to a double-row guide during a transition from the spread position 51 to the closed position 50 and the pitch distance from Di to D3 is reduced. Due to the closed circulation of the conveyor chain, at the entrance and exit of the deflection areas, i.e. at the transition between straight and curved route of the chain links 33, alternating transitions between the spread position 51 and the closed position 50 of the boom 41 take place. As can be seen from Fig. 5a, the distances Da between preforms guided one behind the other in two-row transport are particularly small, which offers various advantages. The small distances D3 lead, for example, to as little radiation energy as possible, which acts on the body region of the preform 1 below its support ring 49 during transport of the preforms 1 in the area of ​​the heating radiators 30 of the heating section 24, escaping upwards in a vertical direction through the large gaps between the preforms 1. As Fig. 5a also illustrates, a first transport row in the two-row transport area is formed by first handling means 39 guided one behind the other, and a second transport row is formed by second handling means 39' guided one behind the other. In the single-row transport area, the first and second handling means 39 and 39' alternate one behind the other.Since guidance takes place on a circular path there, the circular path distance between the handling means 39 and 39' corresponds to the transfer pitch Di on the input wheel 35: the longitudinal axes shown in Figure 5b to two adjacent preforms 1 have this transfer pitch Di. Fig. 5b further shows an exemplary structure of the handling means 39, 39' with a vertically displaceably mounted holding mandrel 56, which has a holding head 57 at its lower end in the vertical direction for holding a preform 1. Radiation shields 46 can be provided, which partially encompass the preforms 1 below a support ring 49 adjoining the mouth region 48 downwards. As shown, the radiation shields 46 can be plate-shaped and each have two recesses 47 concavely machined into the material of the radiation shield 46 at opposite edges. In the two-row transport area of ​​the preforms 1, pairs of radiation shields 46 of two pivoting arms 43 are brought together in such a way that the recesses 47 of the two combined radiation shields 41 are opposite one another and together form an approximately circular cutout that leaves a passage for the body of a preform 1. Figures 6a, 6b, and 6c show a second embodiment of a transport device that allows switching between two-row and single-row transport. The transport device is again designed as a chain with chain links 33, wherein these chain links 33 are pivotable relative to one another to be brought into an extended arrangement on the one hand and into a compressed arrangement on the other. Handling means 39 in the form of transport mandrels are arranged on the chain links 33 and additional intermediate chain links 56 are provided which connect the chain links 33 are connected to one another in an articulated manner. Figures 6a to 6c show only part of a conveyor chain, namely during the transition from a folded position 57 to an extended position 58. It can be seen that the preforms 1 carried on the handling means 39 of the chain links 33 are transported one behind the other in a single row at a distance Di in the transport direction R in the area of ​​the extended position 58 and are transported in two rows in the area of ​​the folded position 57 in two rows running parallel to one another with respect to the transport direction R. Also visible is the small distance D3 between two consecutive preforms 1 in a row in the area of ​​the folded position 57 in comparison to the larger distance Di between two consecutive preforms 1 in the area of ​​the extended position 58.In the area of ​​the stretched position 58, the preforms have the transfer pitch Di from each other as mentioned in the claims, since the preforms 1 are guided there on a circular path, see Fig. 6c. Radiation shields 41 are arranged on the chain links 33. These shields are moved in pairs by the folding movement of the conveyor chain 41 into a shielding position in which they block the space between two consecutive preforms 1 against the passage of radiation. In the extended position 58, the radiation shields 41 are in a release position in which the preforms can be removed from the engagement area of ​​the radiation shields 41 without collision. Fig. 7a and 7b show a partial plan view of a blowing wheel with several blowing stations arranged next to one another in a fully open state (Fig. 7a) and after the blowing stations have been fully closed (Fig. 7b). According to the embodiment in Fig. 7a, a plurality of blowing stations (3) are arranged along a circumference of the blowing wheel (25). Figure 7b shows the main axes of two adjacent stations 3, which lie on the radius of the blowing wheel or define this radius. These main axes coincide with the longitudinal axes of the preforms when the preforms are inserted into the blowing stations. The distance D2 between two adjacent main axes in the circumferential direction therefore corresponds to the transfer pitch distance according to the claims. The mold carriers (5) are pivotable relative to a rotational axis (40), and the mold carriers (6) are rigidly connected to the blowing wheel (25). A parting plane (41) of the blowing station (3) is inclined relative to a radial reference plane (42) of the blowing wheel (25) by an angle of inclination (43), which allows a more compact arrangement on the blowing wheel 25 and is therefore generally preferred. According to the design in Fig. 7a, the blow molds consist of outer mold shells (44, 45) and inner mold shells (not shown in Fig. 7a), which are shaped to the contour of the container (2) to be produced. are provided. According to the operating state of the blow molding station (3) with a maximum opening shown in Fig. 7a, the mold carriers (5) of one blow molding station (3) border on the mold carriers (6) of the adjacent blow molding station (3) or are arranged at a small distance from the respective adjacent mold carrier. To carry out a positioning movement of the pivotable mold carriers (19), a positioning device (47) is used which can be actuated, for example, by cam control. Figures 4a to 4c show an alternative possibility. A cam control (not shown in Fig. 7a) is connected, for example via a control shaft (48), to a linkage lever (49), which is coupled to a control lever (51) via a pivot joint (50). The control lever (51) is coupled to a support lever (53) via a pivot joint (52). A joint axis (54) of the swivel joint (52) is arranged in a positionally variable manner along a guide (56) via a control roller (55).The guide (56) extends with a longitudinal axis substantially in a radial direction with respect to a rotational axis of the blowing wheel (25). By rotating the control shaft (48), the position of the levers (49, 51, 53) is changed. Due to the pivoting movement of the linkage lever (49), the control roller (55) is moved along the guide (56) to a position further outwards with respect to the circumference of the blowing wheel (25). According to the operating state shown in Fig. 7b, the blowing stations (3) are completely closed. The remaining distances between the outer mold shells (44, 45) shown in Fig. 7b result from the fact that the inner mold shells are not shown in the illustration in Fig. 7b. These shells border directly on the parting plane (41). When the blowing station (3) is in the closed position, the linkage lever (49) and the control lever (51) are arranged stretched one behind the other in a radial direction of the blowing wheel (25).In this arrangement, the rotational axis of the blowing wheel (25) (not shown), the control shaft (48), the pivot joint (50), and the pivot joint (52) are essentially located on a radially oriented connecting line. The support lever (53), which is connected to the mold carrier (19) via a pivot joint (57), is guided with its end facing away from the pivot joint (57) against a counterbearing (58) and is supported by the latter. The pivot joint (57), the pivot joint (52), and the counterbearing (58) are arranged along a common connecting line, which is positioned essentially at right angles to the radial direction of the blowing wheel (25). The counterbearing (58) can be designed either as a separate component rigidly connected to the blowing wheel (25) or as an integral part of the mold carrier (20).When the blow molding station (3) is subjected to internal pressure during blow molding, the force transmitted by the support lever (53) is essentially completely absorbed by the counter bearing (58). and does not result in a force being applied to the linkage lever (49) and the control lever (51). In particular, with the positioning of the levers (49, 51, 53) shown in Fig. 7b, it is possible to clamp the mold carriers (19, 20) of a respective blow molding station (3) or the associated blow mold segments relative to one another without additional force being applied to the control shaft (48). Thus, no additional locking of the blow molding stations (3) is required.

Claims

Claims 1. A method for producing containers (2) from thermally conditioned preforms (1) made of a thermoplastic material, in particular PET, preferably using a stretching rod (11), wherein the preforms (1) are brought to a temperature suitable for forming in a heating device (24) through which the preforms are moved in a rotating manner during the movement, in particular to a temperature above the glass transition temperature of the preform material, wherein the preforms (1) are removed from the heating device (24) by a transfer device (35) having a plurality of carrying devices (35') for the preforms at a first pitch (Di), the take-over pitch, guided to a forming device (25) and transferred to the forming device (25) at a second pitch (D2), the transfer pitch,wherein the forming device (25) moves the preforms (1) in a rotating manner and, in the meantime, forms them by introducing a forming fluid under pressure into the container (2), wherein the quotient (D2 / D1) of the transfer pitch and the takeover pitch is greater than 1 and less than 6.5, preferably less than 5.25, more preferably less than 5, finally preferably less than 4.

2. Method according to claim 1, characterized in that the forming device (25) has a plurality of forming stations (3) which are arranged equidistantly circumferentially on a forming wheel (25) driven to a continuous circulating movement, wherein the number of forming stations (3) is greater than 24, more preferably greater than 30, even more preferably greater than or equal to 36 and / or wherein the forming wheel diameter is greater than 2.5 m, preferably greater than 3 m, more preferably less than 3.36 m, more preferably less than 3.25 m, more preferably the output per station (3) is greater than 2555 bottles per hour and / or wherein the peripheral speed of the preform (1) / container (2) on the forming wheel (25) is less than 7.5 m / s and / or wherein the diameter of the transfer device (35) is less than or equal to 1600 mm and / or the number of forming stations (3) is less than 1.6 times the number of carrying devices (35') on the transfer device (35).

3. Method according to claim 1 or 2, characterized in that the preforms (1) are transported in the heating device (24) in two rows along heating radiators (30) and are guided in one row in the region of removal from the heating device (24) and in the region of transfer to the heating device (24).

4. Method according to one of the preceding claims, characterized in that the forming stations (3) have multi-part outer molds (4) that can be opened and closed, and against the inner contour of which the preforms (1) are expanded to form the container (2), consisting of two side shells (5, 6), the inner contour of which defines the lateral outer contour of the container (2) formed therein, and a bottom mold (7), the inner contour of which defines the outer contour of the container (2) in its bottom region, wherein one of the two side shells (5, 6) is arranged immovably relative to the forming wheel (35), while the other side shell (6, 5) is movable relative to the first side shell (5, 6), wherein more preferably the movement of the side shell (5, 6) and the movement of the bottom shell (7) takes place in a mechanically coupled manner,wherein further preferably the stretching rod (11) is driven by a linear motor (50) and further preferably the opening and closing of the mold (4) is also driven by an electric motor (50), wherein further preferably the driving of the stretching rod (11) and the driving of the opening and closing movement of the mold (4) is carried out by a single common drive (50), preferably by a linear motor.

5. Method according to one of the preceding claims, characterized in that the transfer device (35) has a plurality of pivotable tong arms (35') as carrying devices, and the pitch change from the takeover pitch distance (Di) to the transfer pitch distance (D3) is carried out by a pivoting movement of the tong arms (35').

6. Method according to one of the preceding claims, characterized in that the containers (2) are filled after the forming in a filling device and / or closed in a closing device and / or labeled in a labeling device, these devices being arranged in a block with the forming device (25).

7. Device for producing containers (2) from thermally conditioned preforms (1) made of a thermoplastic material, in particular PET, preferably with and using a stretching rod (11), wherein the device has a heating device (24) with a transport device (33) guiding the preforms (1) through the heating device (24) and is controlled and designed to heat the preforms (1) on their way through the heating device (24) to a temperature suitable for forming, in particular to a temperature above the glass transition temperature of the preform material, wherein the device has a transfer device (35) with a plurality of carrying devices (35'), which is arranged and designed to remove the preforms (1) from the heating device (24) at a first pitch (Di), the transfer pitch,to a forming device (25) and to transfer it to the forming device (25) with a second pitch (D3), the transfer pitch, wherein the forming device (25) is designed as a forming wheel (25) which is driven in rotation for continuous circulation and is arranged and designed to move preforms (1) transferred onto the forming wheel in a rotating manner and to form the preform (1) into the container (2) during the circulation by introducing a forming fluid under pressure, wherein the quotient (D2 / D1) of the transfer pitch and the takeover pitch is greater than 1 and less than 6.5, preferably less than 5.25, more preferably less than 5, finally preferably less than 4.

8. Device according to claim 7, characterized in that the forming device (25) has a plurality of forming stations (3) which are arranged equidistantly circumferentially on the forming wheel (25), wherein the number of forming stations (3) is greater than 24, more preferably greater than 30, even more preferably greater than or equal to 36 and / or wherein the forming wheel diameter is greater than 2.5 m, preferably greater than 3 m, more preferably less than 3.36 m, more preferably less than 3.25 m, more preferably the output per station (3) is greater than 2555 bottles per hour and / or wherein the peripheral speed of the preform (1) / container (2) on the forming wheel (25) is less than 7.5 m / s and / orwherein the diameter of the transfer device (35) is less than or equal to 1600 mm and / or the number of forming stations (3) is less than 1.6 times the number of support devices (35') on the transfer device (35).

9. Device according to claim 7 or 8, characterized in that the transport device (33) guiding the preforms through the heating device (24) is designed to transport the preforms (1) in the heating device (24) in two rows along heating radiators (30) and to guide them in one row in the region of removal from the heating device (24) and in the region of transfer to the heating device (24).

10. Device according to one of the preceding claims 7-9, characterized in that the forming stations (3) have multi-part outer molds (4) which can assume an open and a closed state, and against whose inner contour the preforms (1) can be expanded to form the container (2), consisting of two side shells (5, 6), the inner contour of which defines the lateral outer contour of the container (2) formed therein, and a bottom mold (7), the inner contour of which defines the outer contour of the container (2) in its bottom region, wherein one of the two side shells (5, 6) is arranged immovably relative to the forming wheel (25), while the other side shell (6, 5) is movable relative to the first side shell (5, 6), wherein more preferably the movement of the side shell (5, 6) and the movement of the bottom shell (7) are executed in a mechanically coupled manner.wherein further preferably the stretching rod (11) is drive-coupled to a linear motor (50) for carrying out the stretching movement and further preferably the mold (4) is drive-coupled to an electric motor (50) for opening and closing it, wherein further preferably the stretching rod (11) is drive-coupled to a single common drive (50) for carrying out the stretching movement and the mold (4) is drive-coupled to a single common drive (50) for opening and closing it, preferably a linear motor.

11. Device according to one of the preceding claims 7-10, characterized in that the transfer device (35) has a plurality of pivotable tong arms (35') as carrying devices, and the tong arms (35') are arranged and designed to effect the change in pitch from the takeover pitch distance (Di) to the transfer pitch distance (D2) by a pivoting movement of the tong arms (35'), wherein this pivoting movement is preferably predetermined mechanically by a guide cam or by an actuator, e.g. an electric drive.

12. Device according to one of the preceding claims 7-11, characterized in that in the conveying direction R the container (2) is arranged downstream of the forming device (25) and in a blocked construction a filling device for filling the containers and / or a closing device for closing the containers and / or a labeling device for labeling the containers (2) is arranged.

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