Method of operating an IS machine for manufacturing glass containers

Abstract

The invention relates to a method for operating an IS machine for manufacturing glass containers, wherein the IS machine comprises a plurality of blank molds and a plurality of finishing molds and in each case one blank mold interacts with one finishing mold, the method comprising the following method steps, which are performed in each case for one blank mold and one finishing mold of a pair: introducing a glass gob into the blank mold, producing a parison in the blank mold from the glass gob, transferring the parison into the finishing mold, actuating a vacuum valve from a first actuation time point to produce a vacuum in the finishing mold while measuring the evolution of the vacuum pressure, actuating a final blow valve from a second actuation time point later than the first actuation time point by a predetermined duration to produce a final blow pressure, blowing compressed air into the finishing mold from the top while measuring the evolution of the final blow pressure, and checking whether the measured evolution of the vacuum pressure and / or the measured evolution of the final blow pressure meets predetermined conditions. Thus, an option is provided which allows such operation of an IS machine, wherein rejects due to defective manufacturing of glass containers can be effectively identified and in addition preferably only with a low rejection rate of glass containers.

Description

Technical Field

[0001] The invention relates to a method for operating an IS machine for manufacturing glass containers, wherein the IS machine comprises a plurality of blank moulds and a plurality of finishing moulds and in each case one blank mould interacts with one finishing mould, the method comprising the following method steps, which are carried out for each pair of one blank mould and one finishing mould:

[0002] introducing a glass gob into the green body mold,

[0003] producing a preform from a glass gob in the preform mold,

[0004] Transfer the parison to the finishing mold,

[0005] actuating the vacuum valve from a first actuation time point to generate a vacuum in the finishing mold, and

[0006] The final blow valve is actuated from a second actuation time point later than the first actuation time point by a predetermined duration to generate a final blow pressure so that compressed air is blown into the finishing mold from the top. Background Art

[0007] The operation of IS machines for manufacturing glass containers has been known in the prior art for decades. In this regard, the terms "IS machine", "body mold", "finishing mold", "parison", "blowing down", "pre-blowing" and "final blowing" are technical terms known to those skilled in the art and therefore do not need to be explained in detail here. For the sake of clarity, the basic features of the operation of IS machines known from the prior art in the blow-blowing process are briefly described below:

[0008] The glass liquefies at the melting end and flows out of the melting end into the feeder. An elongated glass drop is formed at the head of the feeder by a hoist. The glass drop is introduced into the blank mold through a channel. In this case, the subsequent neck of the glass container to be manufactured points downward. The blank mold base is then placed on the blank mold and the blank mold is closed. Compressed air is blown in from the top so that the glass block provided by the glass drop completely fills the neck mold mounted on the bottom of the blank mold. This step is called blowing down. In the following, the blank mold base is removed and the blank mold is closed at the top by the blank mold base. The glass is pre-blown into the opening thus formed at the bottom by the inflowing compressed air to form a parison. The blank mold is opened, and the pre-blown workpiece, i.e., the parison, is pivoted 180° by a conveying mechanism into the relevant opened finishing mold. During this process, the parison is kept in the neck mold. The neck is then located at the top. The neck mold is then opened, and the conveying mechanism pivots back to the starting position to receive the next parison in the blank mold. At the same time, the finishing mold is closed from the top by the blowing head so that the parison in the finishing mold is finally blown into its final shape by compressed air. The blowing head then pivots back, the finishing mold opens, and the clamp transfers the finished workpiece to the fixing plate. Usually, another mechanism then pushes the finished workpiece onto a conveyor belt, which transports the product to the cooling area.

[0009] For the sake of completeness, it should be noted that the blow-blow process described above is certainly not the only process that can be used to make glass containers by IS machines. For example, it is also known to operate IS machines using a press-blow process. In this process, the parison is not blown, but squeezed by a plunger inserted through a neck mold. This process was first used for wide-necked containers, but is particularly advantageous in narrow-necked bottles.

[0010] Such processes lead to the following problem: when the pressure for final blowing on the one hand and for producing vacuum on the other hand occurs at the same point in time, the pressures are added up and the deformation speed of the glass increases. The increased processing speed leads to cracks, which are called compression cracks. In order to prevent this, as a rule, different final blowing start times and vacuum start times are set in the electronic timer. The time difference should be at least 50 ms. However, since the time until the actual pressure is generated is influenced by factors such as the switching hysteresis of the electronic timer, the pilot air pressure, the valve state, the switch box state and the entire range of pipe lengths and diameters, it has been almost impossible to ensure that only the desired and problem-free pressure for manufacturing glass containers is generated until now. As a result, glass containers are discarded again and again because at least after a certain operating time of the IS machine, the time for applying the corresponding pressure is no longer desired and is no longer associated with the actuation of the relevant valve in a preset manner. Summary of the invention

[0011] Starting from this, the problem addressed by the present invention is to provide an option which allows such an operation of an IS machine, wherein rejects due to defective production of glass containers can be effectively identified and furthermore preferably only with a low reject rate of glass containers.

[0012] This problem is solved by the subject matter of some embodiments.Preferred improvements can be found in other embodiments.

[0013] According to the invention, there is thus provided a method for operating an IS machine for manufacturing glass containers, wherein the IS machine comprises a plurality of blank moulds and a plurality of finishing moulds and in each case one blank mould interacts with one finishing mould, the method comprising the following method steps, which are performed for each pair of one blank mould and one finishing mould:

[0014] Introduce the glass drop into the green body mold,

[0015] The preform is produced from the glass gob in the body mold.

[0016] Transfer the parison to the finishing mold,

[0017] actuating the vacuum valve from a first actuation time point to generate a vacuum in the finishing mold while measuring the evolution of the vacuum pressure,

[0018] actuating the final blow valve from a second actuation time point later than the first actuation time point by a predetermined duration to generate a final blow pressure so that compressed air is blown into the finishing mold from the top, while measuring the evolution of the final blow pressure, and

[0019] It is checked whether the evolution of the measured vacuum pressure and the evolution of the measured final blowing pressure meet predetermined conditions.

[0020] If the measurement of the evolution of the vacuum pressure and / or the measurement of the evolution of the final blow pressure is discussed here, these pressures are detected at relevant points between the corresponding valve, i.e. the vacuum valve or the final blow valve, on the one hand, and the point at which the vacuum pressure or the final blow pressure enters the finishing mold on the other hand. The vacuum pressure and the final blow pressure are accumulated in the finishing mold itself. In this respect, in the context of the present invention, the relevant pressure in the corresponding feed line, i.e. the relevant pressure in the vacuum feed line or the final blow feed line, can be detected, in particular between the vacuum valve or the final blow valve on the one hand and the finishing mold on the other hand.

[0021] It is therefore important for the present invention to measure the evolution of the vacuum pressure and the evolution of the final blow pressure so that a check can be made whether the measured evolution of the vacuum pressure and / or the measured evolution of the final blow pressure has met a predetermined condition. If this check shows that the predetermined condition is not met, various measures can be taken to eliminate defective glass containers from being manufactured and to adjust the operation of the IS machine if necessary, thereby further reducing the scrap rate. In the context of the present invention, there are various options for doing this, which are discussed below by way of example by outlining a preferred configuration of the present invention.

[0022] From this point of view, according to a preferred embodiment of the invention, in the step of checking whether the evolution of the measured vacuum pressure and / or the evolution of the measured final blowing pressure satisfies a predetermined condition, a check is performed as to whether the evolution of the measured vacuum pressure has a predetermined relationship to the evolution of the measured final blowing pressure. In this way, a check can be performed, for example, as to the temporal evolution of the pressures relative to each other, in particular as to whether the final blowing pressure is established too early after the application of the vacuum, so that the total pressure acting on the glass is higher than a value that would normally ensure a defect-free production of the glass container.

[0023] In this respect, it is particularly preferably provided that, in the step of checking whether the evolution of the measured vacuum pressure has a predetermined relationship with the evolution of the measured final blowing pressure, the duration between the time points at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum is determined. In this respect, according to a preferred configuration of the invention, it is provided that, if the duration between the time points at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum is not within a predetermined duration range, the time at which the vacuum valve and / or the final blowing valve is actuated is changed in a subsequent actuation so as to adjust the duration between the time points at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum so as to move it within the predetermined duration range.

[0024] Another preferred configuration of the present invention provides that, in the case where the duration between the time points at which the check shows that the evolution of the final blow pressure and / or the evolution of the vacuum pressure is at a maximum is below a predetermined upper duration limit, a warning message is output. Furthermore, a preferred configuration of the present invention provides that, in the case where the check shows that the duration between the time points at which the evolution of the final blow pressure and / or the evolution of the vacuum pressure is at a maximum is below a lower duration limit, glass containers whose duration during manufacturing is below the lower duration limit are discarded.

[0025] As mentioned above, the time difference between the pressure peaks should generally be above 50 ms. In this respect, according to a preferred refinement of the invention, it is provided that if a time difference between the pressure peaks of less than 50 ms has been identified, the glass container is discarded. For a time between, for example, 50 ms and 100 ms, it is preferably provided that a warning message is output to the operator of the IS machine. Furthermore, preferably, if the duration between the pressure peaks is not within a predetermined duration range, for example from 100 ms to 120 ms, the actuation of the vacuum valve and / or the final blow valve is readjusted.

[0026] A preferred configuration of the invention, which can be implemented as an alternative or in addition to the preferred configuration of the invention described above, provides that, in the step of checking whether the evolution of the measured vacuum pressure and / or the evolution of the measured final blow pressure satisfies a predetermined condition, a check is performed as to whether the evolution of the sum of the vacuum pressure and the final blow pressure does not exceed a predetermined maximum pressure. Therefore, this preferred improvement of the invention does not focus on the time point of the pressure peak, but performs a direct check whether the predetermined maximum pressure is not exceeded in the finishing mold. Preferably, in the case where the check shows that the predetermined maximum pressure has been exceeded, the time of actuating the vacuum valve and / or the final blow valve is changed in the subsequent actuation to adjust the evolution of the sum of the vacuum pressure and the final blow pressure so that the predetermined maximum pressure is no longer exceeded. In particular, in this case, the adjustment is set so that the limit pressure values ​​of the vacuum pressure and the final blow pressure are reached in the shortest possible time.

[0027] Similar to the above, when the maximum pressure only exceeds the first predetermined pressure difference, a warning message is also output here. In addition, when the maximum pressure exceeds the second predetermined pressure difference greater than the first predetermined pressure difference, the glass container that exceeds the second predetermined pressure difference during its manufacture is preferably discarded.

[0028] A preferred configuration of the invention, which can be an alternative or in addition to the above-described preferred configuration of the invention described above, comprises the following additional method steps, which are carried out in each case for a pair of one blank mold and one finishing operation:

[0029] measuring the duration between the point in time when the vacuum valve is actuated and the point in time when the vacuum pressure has reached a predetermined vacuum pressure value, and

[0030] The time of actuating the vacuum valve is changed in subsequent actuations so that the duration between the time point of actuating the vacuum valve and the time point at which the vacuum pressure reaches the predetermined vacuum pressure value is adjusted to a predetermined duration.

[0031] Due to signs of aging of the vacuum valve, it is possible that, despite the fact that the actuation time by means of the electronic timer remains constant, the valve may no longer open and close at the desired time. This can be counteracted by changing the time of actuation of the vacuum valve, as described above. The same applies to the final blow valve, therefore, according to a preferred configuration of the invention, a method is provided comprising the following additional method steps, which are carried out in each case for a pair of a blank mold and a finishing mold:

[0032] measuring the duration between the time point at which the final blow valve is actuated and the time point at which the final blow pressure reaches a predetermined final blow pressure value, and

[0033] The time at which the final blow valve is actuated is changed in subsequent actuations so that the duration between the time point at which the final blow valve is actuated and the time point at which the final blow pressure reaches the predetermined final blow pressure value is adjusted to a predetermined duration.

[0034] However, the present invention does not only include detecting the pressure supplied to the finishing mold. In the context of a preferred improvement of the present invention, in order to manufacture a blank, a glass drop is blown down into the blank mold by compressed air blown into the blank mold from the top, and the glass drop is pre-blown into a parison in the blank mold by compressed air blown into the blank mold from the bottom, wherein, in the step of blowing the glass drop down into the blank mold, a blow-down valve is actuated to generate a blow-down pressure in the blank mold from a third actuation time point, and the evolution of the blow-down pressure is measured at the same time,

[0035] In the step of pre-blowing the glass gob in the blank mold to form the parison, the pre-blowing valve is actuated to generate a pre-blowing pressure in the blank mold from a fourth actuation time point which is later than the third actuation time point by a predetermined duration, while measuring the evolution of the pre-blowing pressure, and the method comprises the following additional method steps which are also carried out in each case for one blank mold and one finishing mold of a pair:

[0036] It is checked whether the evolution of the measured blow-down pressure and / or the evolution of the measured pre-blow pressure meets a predetermined condition.

[0037] This makes it possible, for example, to coordinate the duration and time offset between blow-down and pre-blow and, in particular, independently of the value set in the electronic timer for actuating the valve. In this way, further container defects, such as bulges in the neck of the bottle or uneven glass distribution, can be eliminated.

[0038] By analogy with the preferred configuration of the invention described above in conjunction with the finishing mold, the preferred configuration when detecting the pressure supplied to the blank mold becomes clear. Thus, for example, according to a preferred refinement of the invention, it is provided that the duration between the pressure peaks is determined in order to change the actuation of the blow-down valve and / or the pre-blow valve on this basis, for example, to adjust it to a predetermined duration between the pressure peaks. Furthermore, it is of course also possible to provide a warning message if the desired time difference is not observed. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In the following, the invention will be explained in more detail based on preferred exemplary embodiments and with reference to the accompanying drawings, in which:

[0040] Figure 1 Schematically illustrates an IS machine according to a preferred exemplary embodiment of the present invention,

[0041] Figure 2 Schematically shows Figure 1 Finishing mold system for IS machines in

[0042] Figure 3 Schematically shows Figure 1 The blank mold system of the IS machine in

[0043] Figure 4a shows the evolution of the vacuum pressure during startup,

[0044] Figure 4b shows the evolution of the final blowing pressure during the startup process,

[0045] Figure 5a shows the total pressure of stretched glass when vacuum pressure and final blowing pressure are started simultaneously.

[0046] Figure 5b It shows the change of total pressure when vacuum pressure and final blowing pressure are started at the same time.

[0047] Figure 6a shows the total pressure of the stretched glass when the vacuum pressure and the final blow pressure are started with a significant offset,

[0048] Figure 6b shows the change in total pressure when the vacuum pressure and final blow pressure start with a significant offset,

[0049] Figure 7a shows the total pressure of stretched glass when vacuum pressure and final blowing pressure start at the optimal offset,

[0050] Figure 7b shows the change in total pressure when the vacuum pressure and final blow pressure are started with the optimal offset, and

[0051] Figure 8A flow chart showing a method according to a preferred exemplary embodiment of the present invention is shown. DETAILED DESCRIPTION

[0052] Figure 1 Schematically shown is an IS machine 1 according to a preferred exemplary embodiment of the invention, which is configured to manufacture glass containers, such as beverage bottles, in a blow-blow process. The IS machine 1 comprises a plurality of blank molds 2 and a plurality of finishing molds 3, in each case one blank mold 2 interacting with one finishing mold 3. The sequence of the manufacturing method performed by the IS machine is controlled by a machine controller 8.

[0053] All the blank molds 2 and all the finishing molds 3 are equipped with valves and pressure sensors, thereby forming a blank mold system 13 and a finishing mold system 14 as a whole, as follows. Each finishing mold 3 is equipped with a vacuum feed line 16 and a final blow feed line 15, the vacuum line includes a vacuum valve 4 for generating vacuum in the finishing mold 3 and a vacuum pressure sensor 5 for measuring vacuum pressure, and the final blow feed line includes a final blow valve 6 and a final blow pressure sensor 7. In a similar manner, each blank mold 2 is equipped with a blow-down feed line 17 and a pre-blow feed line 18, the blow-down feed line includes a blow-down valve 9 and a blow-down pressure sensor 10, and the pre-blow feed line includes a pre-blow valve 11 and a pre-blow pressure sensor 12.

[0054] According to preferred exemplary embodiments of the invention described herein, the following method for making a glass container is thus provided, and Figure 8 In the method, the following method steps are performed for each pair of a blank mold 2 and a finishing mold 3. The following description is based on a single pair of a blank mold 2 and a finishing mold 3.

[0055] In a first method step S1, a glass drop is introduced into the blank mold 2. In method step S2, the glass drop is then blown down in the blank mold by means of compressed air blown into the blank mold 2 from the top through the blow-down line 17. The supply of this compressed air is controlled by the machine controller 8 actuating the blow-down valve 9. In method step S3, the glass drop is then pre-blown in the blank mold 2 to form a parison by means of compressed air blown into the blank mold 2 from the bottom through the pre-blow feed line 18. The supply of this compressed air is controlled by the machine controller 8 actuating the pre-blow valve 11. When the parison is produced, the manufacturing process in the blank mold 2 ends, so that in method step S4, the blank is transferred to the finishing mold 3.

[0056] In this mold, in method step S5, the vacuum valve 4 is actuated from a first actuation time point to generate a vacuum in the finishing mold 3. At the same time, the evolution of the vacuum pressure is measured by the vacuum pressure sensor 5. Even before the end of method step S5, method step S6 may begin, in which the final blow valve 6 is actuated from a second actuation time point later than the first actuation time point by a predetermined duration to generate a final blow pressure. In this step, compressed air is blown into the finishing mold 3 from the top through the final blow feed line 15, while the evolution of the final blow pressure is measured by the final blow pressure sensor.

[0057] It is then important that in method step S7 a check is performed as to whether the evolution of the measured vacuum pressure and / or the evolution of the measured final blowing pressure meets predetermined conditions. The preferred exemplary embodiments of the invention described here provide various options for doing so, which options will be described below.

[0058] A preferred configuration of the present invention is that, in step S7 of checking whether the evolution of the measured vacuum pressure and / or the evolution of the measured final blowing pressure meets a predetermined condition, a check is performed to determine whether the evolution of the measured vacuum pressure has a predetermined relationship with the evolution of the measured final blowing pressure, in particular, to determine the duration between the time points when the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at its maximum. It should be clear here that if the duration between the time points when the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at its maximum is not within the predetermined duration range, then in the subsequent actuation, the time when the vacuum valve 4 and / or the final blowing valve 6 is actuated is changed so as to adjust the duration between the time points when the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at its maximum to move it within the predetermined duration range. In this example, the duration range is a range between 100 and 120 ms. The background is as follows:

[0059] The vacuum drawn on the outside of the glass and the final blowing pressure acting on the inside during final blowing are both responsible for the stresses to which the glass is exposed during final blowing in the finishing mold 3. Most importantly, during dynamic final blowing, the pressure gradient is critical to this, while the ultimate pressure that statically presses the glass into the finishing mold is less important. In this process, it can be seen that the vacuum pressure and the blowing pressure for the glass wall act in the same direction.

[0060] To visualize this, in this example, the two pressure curves with increasing pressure are considered as sine functions to illustrate the effect of pressure superposition. The static part of the final blow cannot be seen here. The pressure of -800mbar is assumed to be the vacuum and the pressure of 1500mbar is assumed to be the blowing pressure. 180ms is assumed to be the pressure build-up time. This results in the following Figure 4a The pressure curves and Figure 4bThe pressure curve of the evolution of the final blow pressure is shown. If both pressures can be activated by the machine controller 8, the exact time of the action in the final blow feed line 15 and the vacuum feed line 16 depends on the different components. Therefore, how the two pressure increases are superimposed depends not only on the actuation of the final blow valve 6 and the vacuum valve 4, but also on the switching behavior of the entire signal chain. If the two pressure increases are superimposed exactly, this will result in the following Figure 5a and 5b The pressure evolution and pressure gradient evolution are shown. It can be seen that this leads to a maximum pressure gradient of 20 mbar / ms at an ultimate pressure of 2300 mbar.

[0061] If the vacuum valve 4 and the final blow valve 6 are actually actuated so that the second pressure buildup begins after the first pressure buildup is completed, this will result in a curve of the total pressure and a curve of the total pressure change, such as Figure 6a and 6b As can be seen from these figures, the maximum pressure gradient is only about 13 mbar / ms, but the total pressure build-up time is also at least twice as long in this case, i.e. 360 ms. The ultimate pressure is again 2300 mbar; this has not changed.

[0062] The goal is then to actuate the vacuum valve 4 and the final blow valve 6 wherever possible in such a way that a pressure increase is generated that is as close to the optimal evolution as possible. An optimization is therefore sought according to which the two curves are superimposed so that the pressure increase is limited while having the shortest possible pressure build-up time. For example, a curve optimized in this way looks like it in Figure 7a and 7b Here, the start of the final blow is delayed by 110 ms compared to the start of the application of the vacuum. It is clear that the pressure gradient is also at a maximum of 13 mbar / ms, but the total pressure build-up time has been shortened to 280 ms compared to the conventional solution described above. The ultimate pressure is again 2300 mbar. Therefore, here, a time delay of 110 ms for the actual actuation of the vacuum valve 4 and the final blow valve 6 is optimal. Therefore, as mentioned above, the aim is to adjust this time difference within the range of 100 to 120 ms.

[0063] As already explained, the time difference between the pressure peaks, i.e. the points in time at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum, is usually greater than 50 ms. In this respect, it is provided that the glass container is rejected if a time difference between the pressure peaks of less than 50 ms has been detected. At a time between 50 ms and 100 ms, for example, a warning message is output to the operator of the IS machine, for example in the form of an optical and / or acoustic signal.

[0064] In a preferred exemplary embodiment of the invention described here, there is another option that, in the step of checking whether the evolution of the measured vacuum pressure and / or the evolution of the measured final blowing pressure satisfies a predetermined condition, a check is performed as to whether the evolution of the sum of the vacuum pressure and the final blowing pressure does not exceed a predetermined maximum pressure. When it is indicated that the predetermined maximum pressure has been exceeded, the time of actuating the vacuum valve and / or the final blowing valve is changed in the subsequent actuation to adjust the evolution of the sum of the vacuum pressure and the final blowing pressure so that the predetermined maximum pressure is no longer exceeded. In this case, the regulation is set so that the limit pressure values ​​of the vacuum pressure and the final blowing pressure are reached in the shortest possible time, which has already been explained in principle above according to the basic characteristics.

[0065] Likewise, in the case where the maximum pressure exceeds only the first predetermined pressure difference, a warning message is output, for example in the form of an optical and / or acoustic signal. If the maximum pressure exceeds a second predetermined pressure difference greater than the first predetermined pressure difference, glass containers that exceed the second predetermined pressure difference during manufacture are discarded.

[0066] Another option in the preferred exemplary embodiment of the invention described in the present case involves the execution of additional method steps, which are performed in each case for a pair of one blank mold and one finishing mold, as follows: measuring the duration between the time point at which the vacuum valve is actuated and the time point at which the vacuum pressure reaches a predetermined vacuum pressure value, and changing the time at which the vacuum valve is actuated in a subsequent actuation so as to adjust the duration between the time point at which the vacuum valve is actuated and the time point at which the vacuum pressure reaches the predetermined vacuum pressure value to a predetermined duration. The same is true during the final blow. Here, the duration between the time point at which the final blow valve is actuated and the time point at which the final blow pressure reaches the predetermined final blow pressure value is measured, and changing the time at which the final blow valve is actuated in a subsequent actuation so as to adjust the duration between the time point at which the final blow valve is actuated and the time point at which the final blow pressure reaches the predetermined final blow pressure value to a predetermined duration.

[0067] Furthermore, in the preferred exemplary embodiment of the invention described here, one option is to seek to optimize not only the final blowing but also the pre-blowing. Specifically, in this case, in the step of blowing down the glass drop in the blank mold 2, the blow-down valve 9 is actuated to generate a blow-down pressure in the blank mold 2 from the third actuation time point, and the evolution of the blow-down pressure is measured at the same time, and, in the step of pre-blowing the glass drop in the blank mold 2 to form a parison, the pre-blowing valve 11 is actuated to generate a pre-blowing pressure in the blank mold from a fourth actuation time point later than the third actuation time point for a predetermined duration, and the evolution of the pre-blowing pressure is measured at the same time. Furthermore, the following method steps are additionally provided, which are also performed in each case for all pairs of one blank mold 2 and one finishing mold 3. In this step, it is checked whether the evolution of the measured blow-down pressure and / or the evolution of the measured pre-blowing pressure meet the predetermined conditions. In principle, a method similar to the method described above in relation to the final blowing can be adopted.

[0068] Reference numerals list

[0069] 1 IS Machine

[0070] 2 Blank mold

[0071] 3 Finishing mold

[0072] 4 Vacuum valve

[0073] 5 Vacuum pressure sensor

[0074] 6 Final blow valve

[0075] 7 Final blow pressure sensor

[0076] 8 Machine Controller

[0077] 9 Blow down valve

[0078] 10 Blow down the pressure sensor

[0079] 11 Pre-blow valve

[0080] 12 Pre-blow pressure sensor

[0081] 13. Blank mold system

[0082] 14 Finishing mold system

[0083] 15 Final blowing feed line

[0084] 16 Vacuum feed line

[0085] 17 Blow down the feed line

[0086] 18 Pre-blow feed line

Claims

1. A method for operating an IS machine (1) for manufacturing glass containers, wherein the IS machine (1) comprises a plurality of blank moulds (2) and a plurality of finishing moulds (3), and in each case one blank mould (2) interacts with one finishing mould (3), the method comprising the following method steps performed for each pair of one blank mould (2) and one finishing mould (3): Introducing a glass drop into a green body mold (2), In the body mold (2), a preform is produced from the glass gob. Transfer the parison to the finishing mold (3), actuating the vacuum valve (4) from a first actuation time point to generate a vacuum in the finishing mold (3) while measuring the evolution of the vacuum pressure, actuating the final blow valve (6) from a second actuation time point later than the first actuation time point by a predetermined duration to generate a final blow pressure so that compressed air is blown into the finishing mold from the top, while measuring the evolution of the final blow pressure, and Check whether the evolution of the measured vacuum pressure and the evolution of the measured final blowing pressure meet the predetermined conditions, In the step of checking whether the evolution of the measured vacuum pressure and / or the evolution of the measured final blowing pressure meets a predetermined condition, a check is performed as to whether the evolution of the measured vacuum pressure has a predetermined relationship to the evolution of the measured final blowing pressure.

2. The method according to claim 1 , wherein in the step of checking whether the measured evolution of the vacuum pressure has a predetermined relationship with the measured evolution of the final blowing pressure, the duration between the time points at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum is determined.

3. The method according to claim 2, wherein, in case the check shows that the duration between the time points at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum is not within a predetermined duration range, the time at which the actuated vacuum valve (4) and / or the final blowing valve (6) is actuated is changed in a subsequent actuation so as to adjust the duration between the time points at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum to move it within the predetermined duration range.

4. The method according to claim 2 or 3, wherein a warning message is outputted if a check shows that the duration between the time points at which the evolution of the final blowing pressure and / or the evolution of the vacuum pressure is at a maximum is below a predetermined upper duration limit.

5. The method according to any one of claims 2 to 4, wherein the glass containers whose duration during production is below the lower duration limit are rejected if the inspection shows that the duration between the time points at which the evolution of the final blow pressure and / or the evolution of the vacuum pressure is at a maximum is below a lower duration limit.

6. The method according to claim 1 , wherein in the step of checking whether the evolution of the measured vacuum pressure and / or the evolution of the measured final blowing pressure satisfies a predetermined condition, a check is performed whether the evolution of the sum of the vacuum pressure and the final blowing pressure does not exceed a predetermined maximum pressure.

7. A method according to claim 6, wherein, if the check shows that a predetermined maximum pressure has been exceeded, the time of actuating the vacuum valve (4) and / or the final blow valve (6) is varied in subsequent actuations in order to adjust the evolution of the sum of the vacuum pressure and the final blow pressure so that the predetermined maximum pressure is no longer exceeded.

8. The method according to claim 7, wherein the regulation is set so that the limit pressure values ​​of the vacuum pressure and the final blowing pressure are reached in the shortest possible time.

9. The method according to any one of claims 6 to 8, wherein a warning message is output in case the maximum pressure exceeds only a first predetermined pressure difference.

10. The method according to any one of claims 6 to 9, wherein in case the maximum pressure exceeds a second predetermined pressure difference which is greater than the first predetermined pressure difference, the glass containers which during their manufacture exceeded the second predetermined pressure difference are discarded.

11. The method according to any of the preceding claims, comprising the following additional method steps, which are carried out in each case for a pair of a blank mold (2) and a finishing mold (3): measuring the duration between the time point at which the vacuum valve (4) is actuated and the time point at which the vacuum pressure reaches a predetermined vacuum pressure value, and The time of actuating the vacuum valve (4) is changed in subsequent actuations so that the duration between the time point of actuating the vacuum valve (4) and the time point when the vacuum pressure reaches the predetermined vacuum pressure value is adjusted to a predetermined duration.

12. The method according to any of the preceding claims, comprising the following additional method steps, which are carried out in each case for a pair of a blank mold (2) and a finishing mold (3): measuring the duration between the time point at which the final blow valve (6) is actuated and the time point at which the final blow pressure reaches a predetermined final blow pressure value, and The time of actuating the final blow valve (6) is changed in subsequent actuations so as to adjust the duration between the time point of actuating the final blow valve (6) and the time point when the final blow pressure reaches a predetermined final blow pressure value to a predetermined duration.

13. The method according to any one of the preceding claims, wherein the step of producing a preform from a glass gob in a preform mold (2) comprises the following method steps: By blowing compressed air into the green body mold (2) from the top, the glass gob in the green body mold (2) is blown down, and By blowing compressed air into the blank mold (2) from the bottom, the glass drop in the blank mold (2) is pre-blown to form a blank, wherein In the step of blowing down the glass drop in the blank mold (2), actuating the blow-down valve (9) to generate a blow-down pressure in the blank mold (2) from a third actuation time point, and simultaneously measuring the evolution of the blow-down pressure, In the step of pre-blowing a glass gob in a blank mold (2) to form a preform, actuating a pre-blowing valve (11) to generate a pre-blowing pressure in the blank mold (2) from a fourth actuation time point later than a third actuation time point by a predetermined duration, while measuring the evolution of the pre-blowing pressure, and The method comprises the following additional method steps, which are also carried out in each case for a pair of a blank mold (2) and a finishing mold (3): It is checked whether the evolution of the measured blow-down pressure and / or the evolution of the measured pre-blow pressure meets a predetermined condition.

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