Device and method for producing a container by stretch blow moulding a preform

Abstract

The invention relates to a production device (4) comprising: a stretch rod (14); - a first valve (30) movable between an open position and a closed position; - at least one second valve (36) movable between an open position and a closed position. The first control device (32) is controlled according to a position signal for the stretch rod (14) and the second control device (38) is controlled by a time signal according to a predetermined first time that has elapsed since a change in state of the first valve (30) between the closed position and the open position.

Description

Device and method for producing a container by stretch blow molding a preform

[0001] The present invention relates to a device for producing a container by stretch blow molding a preform, of the type comprising:

[0002] - a stretching rod, arranged to be introduced into the preform and to stretch said preform in an axial direction,

[0003] - an encoder associated with the stretching rod and arranged to emit a position signal representative of the position of the stretching rod relative to the preform,

[0004] - a first valve movable between an open position, in which a source of fluid is placed in fluid communication with an interior volume of the preform, and a closed position, in which said fluid communication is interrupted,

[0005] - a first control device for the first valve arranged to control the passage of the first valve between the closed position and the open position,

[0006] - at least one second valve movable between an open position, in which another source of fluid is placed in fluid communication with the interior volume of the preform, and a closed position, in which said fluid communication is interrupted,

[0007] - at least one second device for controlling the second valve arranged to control the passage of the second valve between the closed position and the open position,

[0008] - at least one clock arranged to emit a time signal.

[0009] The invention also relates to a container production facility comprising such a production device and a method of producing a container in such a production device.

[0010] In such a production facility, preforms are continuously supplied to a production line in which they pass successively through a plurality of functional units interacting with the preforms to heat the preforms, deform them into containers, mark the containers, fill the containers, etc.

[0011] Such an installation comprises in particular a mobile transport system, for example a blowing wheel or carousel, and carrying a plurality of production devices, or stretch blowing station, arranged to each receive a preform in a malleable state and to axially stretch and radially deform the received preform to form a container during the movement of the transport system between an entry point, at which the preform is placed in the production device, and an exit point, at which a formed container is removed from the production device.

[0012] Stretching is carried out by means of a stretching rod moving in the axial direction of the preform in order to apply pressure to the bottom of the preform to stretch it along its axis. Radial deformation is carried out by blowing by introducing compressed air into the preform by means of a blowing device comprising several valves for controlling the introduction of compressed air.

[0013] To produce containers of satisfactory quality, such a production method, which relies on the mechanical properties obtained by the biaxial orientation of the container material, the synchronization of the stretching and blowing steps is essential. Thus, it is desirable for the blowing step to begin when the preform has already undergone a certain degree of stretching but before the preform has been completely stretched in its axial direction, this degree of stretching depending in particular on the nature of the preform, its heating temperature, etc. It is therefore necessary to control the production device so that the blowing is triggered a certain time after the start of the stretching, which begins once the stretching rod has touched the bottom of the preform.

[0014] To ensure this synchronization, it is planned to use a central unit of the installation communicating with the various elements of the production devices and with the transport system via data buses. The central unit receives from the transport system a signal representing its position and from each production device a signal representing the position of the drawing rod relative to the preform. From these signals, the central unit emits control signals to trigger the movement of the drawing rods of the various production devices depending on the position of the transport system and to trigger the blowing in each production device depending on the position of the drawing rod relative to the preform in the respective production devices. Thus, a large number of signals pass through the data buses.

[0015] However, this large number of signals is detrimental to the speed of signal transmission between the various production devices and the central unit. The central unit is then no longer able to receive the signals representing the position of the stretching rods and to emit the corresponding control signals to trigger blowing in the production devices quickly enough for blowing to start properly when the stretching rod is in the desired position in the preform. This results in a deterioration in the quality of the containers produced by the installation.

[0016] Furthermore, such position-based control of the transport system does not allow each of the production devices to be controlled individually to apply different “production recipes” in each of the production devices, which would allow different containers to be produced and / or different preforms to be used in a single production facility.

[0017] One of the aims of the invention is to overcome these drawbacks by proposing a container production device which can be controlled individually independently of the position of a transport system carrying this production device and without going through a data bus connected to a central unit of the production installation.

[0018] To this end, the invention relates to a device for producing a container of the aforementioned type, in which the first control device is controlled as a function of the position signal emitted by the encoder associated with the drawing rod and the second control device is controlled by the time signal emitted by the clock as a function of a first predetermined time elapsed from a change of state of the first valve between the closed position and the open position.

[0019] By controlling the first valve from a position signal representative of the position of the drawing rod relative to the preform and the second valve from a time signal representative of the time elapsed since the change of state of the first valve between the closed position and the open position, the production device is controlled only from information specific to the production device, independently of the position of a transport system carrying this production device and without requiring passage through a data bus connected to the central unit of the production installation. The production device can thus be controlled independently of other production devices carried by the transport system, or even without being carried by such a transport system.By allowing individual control of several production devices, these production devices can produce different containers and / or use different preforms.

[0020] The production device according to the invention may comprise one or more of the following characteristics, considered alone or in any technically conceivable combination:

[0021] - the production device comprises at least one third valve movable between an open position, in which another source of fluid is placed in fluid communication with the interior volume of the preform, and a closed position, in which said fluid communication is interrupted, and a third device for controlling the third valve arranged to control the passage of the third valve between the closed position and the open position, said third control device being controlled by the time signal emitted by the clock as a function of a second predetermined time elapsed from the change of state of the first valve between the closed position and the open position;

[0022] - the production device comprises a stretching rod actuator arranged to control the movement of the stretching rod relative to the preform, said actuator being triggered by at least one trigger signal emitted by at least one sensor and being controlled by the position signal emitted by the encoder;

[0023] - the sensor is a sensor for closing a mold receiving the preform and / or a sensor for the presence of a preform in said mold;

[0024] - the actuator is triggered by two trigger signals, each trigger signal being emitted by a different sensor;

[0025] - the first valve is a pre-blowing valve or a degassing valve;

[0026] - the second valve is a pre-blow valve, a blow-off valve or a recovery valve.

[0027] According to another aspect, the invention also relates to an installation for producing containers by stretch blow molding of preforms, comprising at least one mobile transport system, said transport system carrying at least two production devices as described above, each production device being arranged to produce a container from a preform while the transport system is moving.

[0028] According to an optional feature of the production installation, the position signal triggering the transition of the first valve from the closed position to the open position and / or the first determined time triggering the transition of the second valve from the closed position to the open position are different for the two production devices.

[0029] According to yet another aspect, the invention relates to a method of producing a container by stretch blow molding a preform in a production device as described above, the method comprising the following steps:

[0030] - place a preform in the production device,

[0031] - stretch the preform in the axial direction using the stretching rod,

[0032] - moving the first valve from the closed position to the open position to place the preform in fluid communication with a fluid source,

[0033] - moving the second valve from the closed position to the open position to place the preform in fluid communication with another source of fluid,

[0034] wherein the transition of the first valve from the closed position to the open position is triggered by the first control device driven as a function of the position signal when the stretching rod is in a given position relative to the preform and the transition of the second valve from the closed position to the open position is triggered by the second control device by the time signal after a first predetermined time has elapsed from a change of state of the first valve between the closed position and the open position.

[0035] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0036] is a schematic representation seen from above of a blowing wheel carrying a plurality of production devices,

[0037] - is a schematic cross-sectional representation of a preform and a drawing rod, in an initial position of the drawing rod,

[0038] - is a schematic cross-sectional representation of a preform and a drawing rod, in a position of first contact of the drawing rod,

[0039] - is a schematic cross-sectional representation of a preform and a drawing rod, in a position of end of axial drawing of the drawing rod, and

[0040] - is a schematic representation is a schematic cross-sectional representation of a container formed as a result of axial stretching and radial deformation of a preform.

[0041] With reference to the, a plant for producing containers from preforms1 is described. The production plant comprises a transport system2, also called a carousel or blowing wheel, carrying a plurality of production devices4, or stretch blowing stations, and moving these production devices 4 in a periodic movement. Such a plant is known per se and conventionally comprises a preform heating oven upstream of the transport system 2 and, according to one example, a container filling device downstream of the transport system 2, as well as a device for transporting the preforms into the heating oven and to the transport system 2 and a device for transporting the containers from the transport system 2 to the filling device.Also in a known manner, other devices for processing preforms and / or containers may be provided in the installation, such as a device for sterilizing preforms, a device for labeling containers and a device for capping filled containers. Since these different devices are not part of the invention, they will not be described in more detail here. In a known manner, a control system for the installation makes it possible to control the installation by triggering the different stages of processing of the preforms and containers according to information obtained, for example by sensors6, on the state of the installation, in particular according to the position of the transport system 2, as will be described later. Such a control system is formed by a central unit8 connected to the different elements of the installation by one or more data buses10.

[0042] It is however understood that the production device 4 according to the invention can be used outside the production installation described above, that is to say without necessarily being carried by a transport system and associated with another production device. That being said, the rest of the description will be made within the framework of the production installation described above with several production devices 4.

[0043] According to the embodiment shown in the, the transport system 2 is formed by a blowing wheel also known as a carousel, movable in rotation about an axis of rotation R, which causes the production devices 4 to rotate with the wheel. The rotation speed of the blowing wheel is adjustable and defines the production rate of containers. Indeed, each container is formed between an entry point of the blowing wheel, at which a preform 1 is placed in a production device 4 and an exit point at which a container is removed from the production device 4, the movement of the wheel between the entry point and the exit point corresponding substantially to a complete revolution of the blowing wheel. Thus, the higher the rotation speed of the wheel, the greater the number of containers produced. Alternatively, the transport system 2 is formed by a device for translational movement of the production devices 4.

[0044] An encoder 12 may be associated with the transport system 2 and arranged to emit a signal representative of the position of the transport system 2 at any time. This signal may be used by the central unit to control certain functions of the production devices 4, as will be described later. For this purpose, the encoder 12 transmits the signal representative of the position of the transport system 2 via the data bus 10 to the central unit 8.

[0045] In the case of a transport system 2 formed by a blowing wheel, the position of the transport system 2 is an angular position of the wheel. The angular position of the blowing wheel is formed by an angle relative to a reference position. The reference position corresponds for example to an initial position of a reference production device 4 and the angular position of the blowing wheel at a given instant then corresponds to the angle formed by the position of the reference production device at this given instant relative to the reference position. The initial position of the reference production device corresponds for example to the position of this device at an entry point of the blowing wheel at which a preform 1 is introduced into the production device. In the remainder of the description, it will be considered that the transport system 2 is formed by a blowing wheel.

[0046] In the remainder of the description, the terms angular position of the blowing wheel and angular position of a production device may be used interchangeably. Indeed, since the various production devices 4 are fixed to the blowing wheel, it is understood that knowing the angular position of the reference production device or of the blowing wheel makes it possible to know the angular position of all the production devices 4 carried by the blowing wheel.

[0047] The transport system 2 carries at least two production devices 4. According to the embodiment shown in the, the transport system 2 carries more than two production devices 4 distributed regularly on the periphery of the blowing wheel and moving in rotation with the blowing wheel.

[0048] Each production device 4 comprises, in a conventional manner, at least one stretching rod 14, a blowing device and a preform gripping element (not shown). In addition, the production device 4 may comprise a mold (not shown) defining a molding cavity having the shape of the container to be produced and forming the preform gripping element 1. The remainder of the description will be made considering a preform 1 placed in a mold.

[0049] Each preform 1 has substantially the shape of a test tube extending along an axis A, comprising a body 16 defining an interior volume 18 closed at one axial end by a bottom 20 and open at the other axial end by an opening 22. In a known manner, the opening 22 is for example defined by a neck 24 having the shape of the final neck of the container to be produced. The height of the preform 1 is defined as being the distance separating the bottom 20 from the opening 22. A preform is made of plastic material, such as for example polyethylene terephthalate (PET).

[0050] When the preform 1 is placed in a mold of a production device 4, its axis A is for example substantially parallel to the axis of rotation R of the blowing wheel. It should be noted that the preform 1 is placed in the mold in a malleable state, that is to say capable of being deformed, for example following heating in the heating oven of the preform 1 to a temperature higher than the glass transition temperature of the material of the preform.

[0051] The stretching rod 14 is arranged to stretch in its axial direction A the preform 1, placed in the mold of the corresponding production device 4. In other words, the stretching rod 14 is arranged to deform the preform 1 in order to increase its height, as can be seen by comparing figures. 3 and 4. To do this, the stretching rod 14 is movable in translation in the axial direction from an initial position, shown in the. In the initial position, the stretching rod 14 extends outside the preform 1. To stretch the preform 1, the stretching rod 14 is moved inside the preform 1, passing through the opening 22 to be introduced into the interior volume 18. The stretching rod 14 is in particular moved into a first contact position, or zero point, shown in the, in which the tip 25 of the stretching rod 14 is in contact with the bottom 20 of the preform 1 but has not started stretching the latter.By continuing the movement of the stretching rod 14 in the axial direction A beyond the first contact position, the stretching rod 14 exerts a force in the axial direction on the bottom 20 of the preform 1 and stretches the latter in this direction due to the malleable state of the preform. The movement of the stretching rod 14 is continued until reaching an axial end of stretching position, also called point ten and shown in the, in which the preform 1 has reached the desired stretch. This position is for example reached when the bottom 20 of the preform touches the bottom of the molding cavity formed by the mold. After reaching the axial end of stretching position, the stretching rod 14 is moved in the opposite direction to return it to the initial position. The movement of the stretching rod 14 is controlled by an actuator 26 connected to the central unit 8 by the data bus 10.

[0052] An encoder 28 is associated with the stretching rod 14 to emit a signal representative of the position of the stretching rod 14 at any time. The encoder 28 is arranged to emit a position signal representative of the position of the stretching rod 14 relative to the preform 1. The position signal is for example an analog signal used to control the production device 4, as will be described later.

[0053] The blowing device is arranged to inject compressed air into the interior volume 18 of the preform 1 in order to deform the preform 1 in radial directions, perpendicular to the axial direction A, as shown in the, and give it its container shape, as shown in the. For this purpose, the blowing device comprises a first valve 30 closing or opening the fluid communication between the interior volume 18 of the preform 1 and a fluid source. According to one embodiment, the fluid source is a source of compressed air, the first valve 30 then being a so-called “pre-blowing” valve. The pressure of the compressed air is then, for example, greater than 3 bars. Alternatively, the first valve 30 is a degassing valve.

[0054] The opening of the first valve 30 is controlled by a first control device 32 and is synchronized with the movement of the drawing rod 14 so that this opening occurs at a given instant between the first contact position and the end of axial drawing position of the drawing rod 14. In other words, the opening of the valve 30 is triggered at a precise instant between point zero and point ten. Thus, the first control device 32 is arranged to emit a signal for opening the first valve 30 when the drawing rod 14 is in a determined position between point zero and point ten.

[0055] As shown in the, the actuator 26 and the first control device 32 are provided on the production device 4, i.e. they move in rotation with the production device 4 instead of being positioned on a fixed part of the installation with the central unit 8, as is usually the case. This also means that there is one actuator 26 and one first control device 32 per production device 4 and that these are separate elements from the central unit 8.

[0056] Thus, the position signal emitted by the encoder 28 can be transmitted directly to the actuator 26 and to the first control device 32 to control them as a function of the position of the stretching rod 14 relative to the preform 1. By directly, it is meant that the position signal does not pass through the data bus 10 or through the central unit 8. The transmission of the position signal is done by cabling 34 adapted to transmit the position signal, which is for example an analog signal. In other words, unlike what must be provided when the signals pass through the data bus 10, it is not necessary in the installation according to the invention to convert the position signal into a digital signal.

[0057] The position signal is used by the actuator 26 to control the movement of the drawing rod 14 in a control loop, as known per se. The actuator 26 is for example formed by a servomotor actuating the movement of the drawing rod 14 and controlled by means of the position signal.

[0058] The position signal is used by the first control device 32 to trigger the first valve 30 to move from the closed position to the open position when the drawing rod 14 is in the desired position between the zero point and the ten point. In other words, when the first control device 32 receives the signal indicating that the drawing rod 14 is in the desired position, the first control device 32 emits the opening signal triggering the opening of the first valve 30. By not passing through the data bus 10 and the central unit 8, a speed of transmission of the signals is ensured such that the opening of the first valve 30 can occur in a satisfactory time after the drawing rod 14 has reached the desired position. More particularly, the signal transmission time between the encoder 28 and the first control device 32 is less than 400 µs.

[0059] The control of the first valve 30 as a function of the stretching rod 14 has been described when the stretching rod 14 moves towards the bottom of the preform 2. It is however understood that the invention also applies to control when the stretching rod 14 rises, that is to say when the stretching rod 14 moves to be extracted from the preform after the stretching rod 14 has stretched the latter in the axial direction.

[0060] The production device further comprises a second valve 36 closing or opening the fluid communication between the interior volume 18 of the preform 1 and another source of fluid. According to one embodiment, the source of fluid is a source of compressed air, the second valve 36 then being a pre-blowing valve when the first valve 30 is a degassing valve or a so-called “blowing” valve when the first valve 30 is a pre-blowing valve. In the case of a blowing valve, the pressure of the compressed air is for example between 10 and 40 bars. Alternatively, the second valve 36 is a degassing or recovery valve.

[0061] The opening of the second valve 36 is controlled by a second control device 38 after a first predetermined time has elapsed from a change in state of the first valve 30 between the closed position and the open position. By “from a change in state of the first valve 30 between the closed position and the open position”, it is meant that the predetermined time is measured from the passage of the first valve 30 from the closed position to the open position or, alternatively, from the passage of the first valve 30 from the open position to the closed position. Thus, the second control device 38 is arranged to emit a signal for opening the second valve 36 after a first predetermined time has elapsed since the emission of the opening signal or a closing signal by the first control device 32.Like the first control device 32, the second control device 38 is also carried by the production device 4 and each production device 4 comprises a second control device 38.

[0062] To control the second control device 38 as a function of the time elapsed from the change of state of the first valve 30, the production device 4 comprises a clock 40 arranged to emit a time signal which is transmitted to the second control device 38. When the time signal corresponds to the first predetermined time, the second control device 38 emits the signal for opening the second valve 36. The clock 40 is also carried by the production device 4 so that the first predetermined time can be different from one production device 4 to another and the time signal does not pass through the data bus 10 or through the central unit 8. The first predetermined time depends on the nature of the first and second valves 30 and 36, the preform and the container to be produced. Thus, the first predetermined time is for example selected in a production recipe of a given container associated with a given preform.

[0063] By controlling the second control device 38 as a function of the first predetermined time, the opening of the second valve 36 is thus not carried out as a function of the angular position of the production device 4, which makes it possible to improve the production of the container and its repeatability. Indeed, the determination of the angular position of the production device 4 lacks precision, which results in an inaccuracy of the emission of the opening signal by the second control device 38 when the latter is controlled as a function of the angular position of the production device 4. Furthermore, due to this inaccuracy, the time of emission of the opening or closing signal can vary from one cycle to another, which is detrimental to the repeatability of the process. By controlling the control device 38 as a function of the first predetermined time, this inaccuracy is eliminated.Furthermore, this time control also makes it possible to produce different containers and / or to use different preforms 1 from one production device 4 to another carried by the same wheel. Indeed, each production device 4 can operate independently of the other production devices 4 and independently of the angular position of the production devices 4. In other words, the first predetermined time can be different from one production device 4 to another to produce different containers and / or use different preforms 1. Similarly, the position of the drawing rod 14 used to control the passage of the first valve 30 from the closed position to the open position can be different from one production device 4 to another carried by the same blowing wheel.

[0064] This sequential control of the second valve 36 can of course be applied to all the additional valves opening after the first valve 30 of the production device 4. In other words, according to one embodiment, the production device 4 comprises at least one third valve 42 movable between an open position, in which another source of fluid is placed in fluid communication with the interior volume of the preform 1, and a closed position, in which this fluid communication is interrupted. The third valve 42 is then controlled by a third control device 44 arranged to control the passage of the third valve 42 from the closed position to the open position. The third control device 44 is controlled by the time signal emitted by the clock 40 as a function of a second predetermined time elapsed from a change of state of the first valve 30 between the closed position and the open position.The second predetermined time is greater than the first predetermined time such that the third valve 42 moves from the open position to the closed position after the second valve 36.

[0065] Thus, the invention applies to all the valves of the production device 4 opening after the first valve 30, these valves after the first valve 30 being controlled sequentially as a function of predetermined times after the change of state of the first valve 30. In this way, the entire production device 4 is controlled independently of the other production devices 4 and of the angular position of the production device 4. It is understood that the passage of the first valve 30, of the second valve 36, of the third valve 42 and of any additional valves from the open position to the closed position after the opening of these valves is also controlled sequentially as a function of predetermined times elapsed after the change of state of the first valve 30 from the time signal emitted by the clock 40.

[0066] The valves controlled sequentially from the third valve 42 are, for example, another blowing valve, one or more recovery valves and / or a flushing valve. The different predetermined times used to control these valves are, for example, part of a recipe for producing a given container from a given preform.

[0067] A method of producing a container from a preform 1, using the production device 4 described above, will now be described.

[0068] A preform 1 is first placed in the production device 4, for example in a mold thereof, the mold having the shape of the container to be produced. The mold is closed, for example at a particular angular position of the transport system 2 and the actuator 26 of the drawing rod 14 is triggered to start the movement of the drawing rod 14 towards the bottom of the preform 1. The triggering of the actuator 26 is done for example upon receipt of at least one trigger signal emitted by at least one sensor 46 of the production device 4. Such a sensor 46 is for example a sensor for closing the mold receiving the preform and / or a sensor for the presence of a preform in this mold. According to one embodiment, the actuator 26 is triggered by two trigger signals, each trigger signal being emitted by a different sensor, for example a sensor for closing the mold and a sensor for the presence of a preform 1 in the mold.

[0069] The movement of the stretching rod 14 is controlled by the position signal emitted by the encoder 28 to stretch the preform in the axial direction, as shown in the.

[0070] The opening of the first valve 30 is then controlled as a function of this position signal when the stretching rod 14 is in a particular position relative to the preform 1 during the axial stretching of the preform 1 or after this axial stretching. The radial deformation of the preform 1 then takes place, as shown in the.

[0071] The opening of the second valve 36 is then controlled by the time signal emitted by the clock 40 when the first predetermined time has elapsed in order to form the container, as shown in the.

[0072] It is understood that when more than two valves are required to form the container, the opening of the additional valve(s) is also controlled by the time signal emitted by the clock 40 at the lapse of different predetermined times, as previously described.

[0073] At the exit position of the production device 4, the mold is opened and the produced container is removed from the mold. The opening of the mold is, for example, controlled as a function of the angular position of the production device 4.

[0074] By lightening the information load carried by the data bus 10, this freed load can be used to convey a greater amount of information on the state of the production installation to the central unit 8 and thus further improve its operation.

Claims

Device (4) for producing a container by stretch-blow molding a preform (1) comprising:- a stretching rod (14), arranged to be introduced into the preform (1) and to stretch said preform (1) in an axial direction (A),- an encoder (28) associated with the stretching rod (14) and arranged to emit a position signal representative of the position of the stretching rod (14) relative to the preform (1),- a first valve (30) movable between an open position, in which a source of fluid is placed in fluid communication with an interior volume of the preform (1), and a closed position, in which said fluid communication is interrupted,- a first control device (32) of the first valve (30) arranged to control the passage of the first valve (30) between the closed position and the open position,- at least one second valve (36) movable between an open position,in which another source of fluid is placed in fluid communication with the interior volume of the preform (1), and a closed position, in which said fluid communication is interrupted,- at least one second control device (38) of the second valve (36) arranged to control the passage of the second valve (36) between the closed position and the open position,- at least one clock (40) arranged to emit a time signal,characterized in that the first control device (32) is controlled as a function of the position signal emitted by the encoder (28) associated with the drawing rod (14) and the second control device (38) is controlled by the time signal emitted by the clock (40) as a function of a first predetermined time elapsed from a change of state of the first valve (30) between the closed position and the open position., Production device according to claim 1, comprising at least one third valve (42) movable between an open position, in which another source of fluid is placed in fluid communication with the interior volume of the preform (1), and a closed position, in which said fluid communication is interrupted, and a third control device (44) of the third valve (42) arranged to control the passage of the third valve (42) between the closed position and the open position, said third control device (44) being controlled by the time signal emitted by the clock (40) as a function of a second predetermined time elapsed from the change of state of the first valve (30) between the closed position and the open position. Production device according to claim 1 or 2, comprising an actuator (26) of the stretching rod (14) arranged to control the movement of the stretching rod (14) relative to the preform, said actuator (26) being triggered by at least one trigger signal emitted by at least one sensor (46) and being controlled by the position signal emitted by the encoder (28). Production device according to claim 3, wherein the sensor (46) is a sensor for closing a mold receiving the preform and / or a sensor for the presence of a preform in said mold. Production device according to claim 3 or 4, wherein the actuator (26) is triggered by two trigger signals, each trigger signal being emitted by a different sensor (46). Production device according to any one of claims 1 to 5, wherein the first valve (30) is a pre-blowing valve or a degassing valve. Production device according to any one of claims 1 to 6, wherein the second valve (36) is a pre-blow valve, a blow valve or a recovery valve. Installation for producing containers by stretch blow molding of preforms (1), comprising at least one mobile transport system (2), said transport system (2) carrying at least two production devices (4) according to any one of claims 1 to 7, each production device (4) being arranged to produce a container from a preform (1) while the transport system (2) is moving. Production installation according to claim 8, wherein the position signal triggering the transition of the first valve (30) from the closed position to the open position and / or the first determined time triggering the transition of the second valve (36) from the closed position to the open position are different for the two production devices (4). Method for producing a container by stretch blow molding a preform (1) in a production device (4) according to any one of claims 1 to 7, said method comprising the following steps:- placing a preform (1) in the production device (4),- stretching the preform (1) in the axial direction (A) by means of the stretching rod (14),- moving the first valve (30) from the closed position to the open position to place the preform (1) in fluid communication with a fluid source,- moving the second valve (36) from the closed position to the open position to place the preform (1) in fluid communication with another fluid source,characterized in that the passage of the first valve (30) from the closed position to the open position is triggered by the first control device (32) controlled as a function of the position signal when the drawing rod (14) is in a given position relative to the preform (1) and the passage of the second valve (36) from the closed position to the open position is triggered by the second control device (38) by the time signal after a first predetermined time has elapsed from a change of state of the first valve (30) between the closed position and the open position.,

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