EP3450334A1 - Operation of a shrinking device of an automatic bundling machine - Google Patents

Abstract

The invention relates to a method of operating a retraction device (1) of an automatic wrapping machine (2) for use in a product treatment plant (3) delivered in the form of bundles (4) which each group includes a plurality of products (3) held together with a shrink film (5); said retraction device (1) being provided with a shrinkage furnace (6) comprising at least one heating member (7) for heating the furnace air (6) and at least one circulation member (8) for air for distributing hot air in the oven (6); said method of operation comprising a production mode in which the shrinkwrapper (2) is set to produce and a superficial standby mode, conducive to energy saving; characterized in that the superficial standby mode comprises reducing the speed of at least one air circulation member (8) relative to the production mode to a non-zero value. The invention also relates to a corresponding device.

Description

The present invention relates to the field of production and packaging of products, more particularly, at the level of a retraction device of an automatic shrinkwrapper. The object of the invention is therefore, on the one hand, a method of operating such a retraction device and, on the other hand, a device implementing this method.

In this field, the treated products are of the type bottles, bottles, cans, etc. and undergo a first so-called production phase during which they are finalized to the unit, that is to say substantially filled, plugged, and labeled.

After this first preparation step leading to a ready-to-use product, a second conditioning step is carried out in order to obtain, at the output, batches of several products, grouped together in a rectangular matrix, with or without a quinconage. and held together by a coating of the plastic film type, with or without a bottom portion in the form of tray or plate, in particular cardboard, for example. At the end of this second stage of packaging, the products are therefore in a group in which they are maintained, as a burden, for example, such burdens are then generally arranged on pallets for easier shipping.

A shrinkwrapper is conventionally used to coat a film around these matrix products and then retract it under the action of heat, with the aid of a retraction device, so as to ensure the maintenance together of the various products of the same matrix. In general, the shrinkwrappers used for the products treated in the present invention are shrinkwrappers for operating at a high rate, that is to say, shrinkwrappers not requiring an operator in normal operation, that is to say, automatic wrapping machines.

In recent years, for both economic and environmental reasons, a constant goal is to limit energy consumption within product production and packaging lines as mentioned above. A more specific effort is made with regard to the consumption of the retraction device of the shrinkwrapper, as it is one of the most energy-consuming elements of line. This effort relates more specifically to the establishment of a standby mode to reduce energy consumption when the shrinkwrapper does not produce, for example, because of a failure of a machine upstream or downstream on the line, or, in the event of jamming or falling of a product.

For example, demand WO 2011/144231 proposes the installation of a closing device at the inlet and the outlet of the oven of the retraction device of an automatic shrinkwrapper. These devices are operated when the shrinkwrapper is not in production phase, in order to limit heat loss outside the oven.

However, it has been shown that the influence of this type of device is low on the energy consumption of a retraction device.

Thus, there remains a need to improve the existing by having a method for significantly saving energy in the moments of inactivity of the shrinkwrapper. Preferably, such a method should not impact the operation of the production and packaging line. In other words, the shrinkwrapper should preferably be ready to restart the production as soon as products are available again to be processed by the shrinkwrapper and / or as soon as the conveyor placed downstream of the shrinkwrapper is ready to receive again. burdens.

The invention thus aims to propose a solution in which the retraction device can operate in a standby mode when the shrinkwrapper can not produce, so as to cause significant energy savings while allowing the shrinkwrapper to resume production as soon as possible. when the event that led to its shutdown no longer has any impact on the shrink-wrapper's ability to process products.

To do this, the invention proposes to act in particular on the stirring of the hot air in the oven of the retraction device. Indeed, the retraction device comprises an oven in which the hot air is stirred using at least one air circulation member (generally represented by a turbine) to distribute it so as to ensure obtaining a good quality burden. The present invention is based on the operation of the turbines at a reduced speed when the shrinkwrapper is not used, compared to the speed applied when the shrinkwrapper is in operation.

The subject of the invention is thus a method of operating a retraction device of an automatic shrinkwrapper intended to be used in a processing plant for products delivered in the form of bundles, each grouping together several products held together with the aid of a shrink film, said retraction device being provided with a retraction furnace comprising at least one heating member for heating the oven air and at least one air circulation member for distributing the hot air in the oven ; said operating method comprising a production mode in which the shrinkwrapper is set to produce and a superficial standby mode, conducive to energy saving.

This method is characterized in that the superficial standby mode comprises reducing the speed of at least one air circulation member relative to the production mode to a non-zero value.

• un four de rétraction comprenant au moins un organe de chauffage destiné à chauffer l'air du four et au moins un organe de circulation d'air destiné à répartir l'air chaud dans le four ; et
• un organe de commande configuré pour recevoir au moins un signal de mise en mode veille superficielle ou de retour en mode production et enclencher le mode correspondant au signal reçu ;

ledit dispositif étant configuré pour que lors du mode veille superficielle, la vitesse d'au moins un organe de circulation d'air soit réduite par rapport au mode production, jusqu'à une valeur non nulle.Another subject of the invention is a device implementing this method, namely a retraction device of an automatic shrinkwrapper intended to be used in a processing plant for products delivered in the form of bundles, each grouping together several products held together with each other. using a shrink film; said device being configured to operate at least in a production mode in which the shrinkwrapper is set to produce or a superficial standby mode conducive to energy saving, said device comprising at least:

• a retraction furnace comprising at least one heating member for heating the furnace air and at least one air circulation member for distributing the hot air into the furnace; and
• a controller configured to receive at least one superimposed standby mode signal or return to production mode and engage the mode corresponding to the received signal;

said device being configured so that during the superficial standby mode, the speed of at least one air circulation member is reduced compared to the production mode, to a non-zero value.

• la figure 1 illustre schématiquement une fardeleuse automatique apte à fonctionner suivant le procédé de fonctionnement de l'invention, et
• la figure 2 représente schématiquement la gestion des différents modes de fonctionnement d'un dispositif de rétraction.

The invention will be better understood from the description below, which is based on possible embodiments, explained in an illustrative and non-limiting manner, with reference to the appended figures, in which:

• the figure 1 schematically illustrates an automatic shrinkwrapper capable of operating according to the operating method of the invention, and
• the figure 2 schematically represents the management of the various modes of operation of a retraction device.

The invention therefore first of all relates to a method of operating a retraction device 1 of an automatic shrinkwrapper 2 intended to be used in a processing installation of products 3 delivered in the form of bundles 4 which each include several 3 products held together using a shrink film 5.

In general, the products 3 are of the bottle, vial, can, cans or other type. The method according to the invention relates to the operation of a retraction device 1 of an automatic shrinkwrapper 2 acting on the products 3.

Generally, in a product treatment plant 3 delivered in the form of bundles 4, upstream of the bundling machine 2, the products 3 are finalized one by one through filling, capping and possibly labeling steps. They can also be manufactured, in particular from a preform. Other steps can be provided within a production line, such as for example a washing step, sterilization for example or crimping, especially when the products 3 are cans.

Just before the wrapping operated by the shrinkwrapper 2, the products 3 are grouped in batches of several products in principle in contact with each other in matrix form with or without quinconcage. Usually, products 3 extend along both edges of the die. At this stage, they are generally arranged vertically, that is to say with their largest dimension extending along the vertical direction and with their opening upwards or downwards.

The wrapping machine 2 then has the role of coating the batches of products 3 with a heat-shrinkable film 5 and then shrink the film using a retraction device 1, in order to keep the products 3 of the same batch together.

There are several types of shrinkwrappers, namely, manual, semi-automatic and automatic shrink wrappers. The present invention focuses solely on automatic wrapping machines 2, which are the only ones to to be able to ensure a sufficiently high rate to meet the production requirements of the type of products concerned by the present invention.

For the purposes of the present invention, the term "automatic shrinkwrappers" means shrinkwrappers which do not require a human operator during the production phase, apart from carrying out maintenance operations, to solve a problem or possibly to supply the shrinkwrapper with products (the latter case concerns only certain models of shrinkwrappers). Thus, shrinkwrappers in which the coating of the film around the batch or the realization of a weld of the film before the retraction step are performed manually, are not considered automatic shrink wrappers within the meaning of the present invention. Preferably, the present invention focuses on automatic shrinkwrappers whose feed is also automatic, that is to say that it does not require human intervention. Automatic wrappers, within the meaning of the present invention, therefore generally have increased autonomy and lower operator cost, compared with other shrinkwrappers.

Some shrinkwrappers include a solder unit for sealing the wrapped film around the batches prior to shrinkage of the film within a shrink device. Preferably, the automatic shrinkwrappers 2 suitable for the present invention are devoid of such a welding unit.

Downstream of an automatic shrinkwrapper 2, a product treatment facility may comprise a palletizer. Such a machine is intended to deposit the bundles delivered by the shrinkwrapper 2 on a pallet, to facilitate their transport.

• au moins un organe de chauffage 7 destiné à chauffer l'air du four 6, et
• au moins un organe 8 de circulation d'air destiné à répartir l'air chaud dans le four 6.

The retraction device 1 according to the invention is provided with a retraction furnace 6 comprising:

• at least one heating member 7 for heating the air of the oven 6, and
• at least one air circulation member 8 for distributing the hot air in the oven 6.

The retraction furnace 6, also called a tunnel or shrink tunnel, is the element which makes it possible to provide the heat necessary to shrink the film arranged around a batch of products. In principle, the organ (s) 8 of air circulation of the furnace 6 is (are) shown (s) by a (of) turbine (s), but can (f) be represented (s) by any other organ able to stir the air within 6. In the rest of the text, expressions "Turbine" and "air circulation member" will be used indifferently to designate a member 8 of air circulation without limiting the scope of the application to a specific member capable of distributing the air in the oven 6.

In general, a retraction tunnel 6 is composed of one to five modules 12 arranged following each other separated from a wall 13 between each module. Each module generally comprises a heating element 7, also called a heating block associated with a turbine 8. Each module 12 then operates independently, which makes it possible to adjust the conditions within the tunnel to optimize the formation of the burden. In the rest of the text, the terms "heater 7" or equivalent, and "turbine 8" or the like, will appear indifferently singular or plural, without limiting the present invention to ovens 6 with one or with 12. These terms are not limited to furnaces with only one or more heating elements 7 or to furnaces with one or more turbines 8.

The heating member 7 is preferably represented by a gas burner or by electrical resistors. It is intended to provide the amount of heat necessary for the oven 6 to reach its target temperature by heating the air in the oven 6. Thus, the heating member 7 operates at a given power adjusted according to the set temperature , corresponding to the temperature that must reach the oven air.

The air circulation member 8 (or turbine 8) is then used to distribute the air heated by the heating block 7 in the oven 6 in order to obtain a flow of hot air of a nature to form a burden of good quality ie . with the least possible folds and allowing a good maintenance of a lot of products 3.

In order to optimize the energy consumption, the operating method of the present invention comprises a production mode in which the shrinkwrapper 2 is set to produce and a superficial standby mode, conducive to energy saving. In particular, in production mode, the shrinkwrapper is set to produce normally, in terms of rate and quantity.

When the operating method according to the invention is in production mode, the retraction device 1 is set so that a retractable film placed around a batch of products 3 which circulates in this device 1 is optimally shrinking to form a burden 4. Traditionally, this mode of operation is the one used at any time during a production phase, even when there is a breakdown on the line, preventing the shrinkwrapper 2 from functioning. . In the context of the present invention, this mode is preferentially used only when the shrinkwrapper 2 produces, that is to say when it delivers burdens 4.

The superficial standby mode meanwhile, corresponds to an economic mode intended to limit the energy consumption of the retraction device 1, when the shrinkwrapper 2 can not produce. When the operating method is in superficial standby mode, certain settings are modified with respect to the production mode, so as to optimize energy consumption, in particular by reducing the expense and / or keeping as much as possible the heat of the oven 6 in view from return to production mode. Thus the adjustments applied to the retraction device in superficial standby mode are such that they do not allow the formation of a necking of satisfactory quality, or even do not allow the formation of a necking.

The superficial standby mode is therefore used when the shrinkwrapper 2 can not produce, for example due to the absence of products 3 in particular due to a failure occurring on the production line. Such a failure may as well be at the level of the shrinkwrapper 2 upstream or downstream of this machine. Another reason preventing the shrinkwrapper 2 from producing may be a falling product 3, a product jam 3, a maintenance operation or when the operator decides to temporarily stop production.

The management of the transition from the production mode to the superficial standby mode and vice versa can be managed by a control member 15 belonging to the retraction device 1. Such a member 15 receives a signal coming either from an operator or directly from an element of the production line and starts the mode corresponding to the signal.

The operating method according to the invention is characterized in that the superficial standby mode comprises reducing the speed of at least one air circulation member 8 relative to the production mode, up to a non-zero value.

The reduction of the speed of an air circulation member 8 corresponds to the reduction of its rotational speed, that is, its rotation frequency. In general, the reduction of the speed of a turbine 8 corresponds to the reduction of its operating power. This reduction in speed causes a less rapid circulation of air within the retraction device 1 and therefore a lower flow rate and mixing of the air with respect to the production mode. Preferably, the speed of all the turbines 8 of the retraction device 1 used in the invention is reduced compared to the production mode, up to a non-zero value.

In production mode, the furnace 8 turbines 6 operate at a given speed, adjusted to allow an optimal air mixing for the purpose of the formation of burdens 4. The inventors have found that during a shutdown of the shrinkwrapper 2 it is not necessary to stir the air as intensely as when the shrinkwrapper 2 produces since burdens 4 are not formed. Slowing down the operating speed of a turbine 8 advantageously makes it possible to achieve significant energy savings. In addition, the fact that the turbine 8 is slowed down, but not stopped, advantageously makes it possible to cool the heating block 7 and thus considerably limit the risk of deterioration of the heating element 7. This advantageously results in less air mixing in the shrink oven 6 and therefore a limitation of the heat loss out of the oven 6.

According to an additional possible characteristic of the operating method, during the superficial standby mode, the speed of at least one air circulation member 8, or even of all the air circulation members 8, is reduced to a value ranging from 10 to 90%, preferably from 30 to 80%, in particular from 50 to 70% of the speed in production mode.

When the furnace 6 comprises several turbines 8, the speed of each turbine 8 can be reduced in a different proportion. For example the speed of the turbine 8 of a given module can be reduced by 20% while the speed of the turbine of another module can be reduced by 50%. Preferably, the speed of all the turbines 8 of the furnace 6 is reduced in a substantially equivalent proportion.

In general, the speed of operation of a turbine 8 in production mode is 800 to 2500 revolutions / minute. In superficial standby mode, it is preferably from 500 to 1000 rpm.

According to a possible additional feature of the operating method, the superficial standby mode further comprises lowering the setpoint temperature of the oven 6 by a preset value with respect to the production mode to a so-called setpoint value in standby mode.

The set temperature of the oven 6 corresponds to the target temperature of the oven. The temperature of the oven 6 corresponds to the temperature of the air circulating there. It is therefore understood that the set temperature may be different depending on the mode in which the retraction device 1 operates. It is also understood that the temperature of the oven 6 does not necessarily correspond to the set temperature. The temperature of the oven 6 is generally measured throughout the process according to the invention, in principle using a thermocouple. During the production mode, the oven is therefore generally at its set temperature in production mode, which is about 200 ° C. When the oven 6 has several modules, the temperature setpoint, and therefore the measured temperature may vary slightly from one module to another for the sake of optimizing the conditions for obtaining a better quality burden. In superficial standby mode, the set temperature of the oven 6 can therefore be lowered by a predetermined value, which means that if the oven 6 has several modules, the set temperature can be lowered by a preset value in each module. When the temperature setpoint is lowered, the heating element (s) is (are) controlled, in particular off, to allow the oven to reach the setpoint temperature of the superficial standby mode.

When the superficial standby mode comprises lowering the temperature setpoint of the oven 6 by a predetermined value, the energy saving achieved is advantageous for several reasons. Firstly, a reduction in the set temperature of the furnace 6 reduces or even stops the energy consumption of the heating member (s). turbine 8 also operates at a reduced speed, the air is stirred less within the oven 6 which allows the oven temperature to lower more slowly than if the turbine 8 was operating in normal mode. This results in better heat preservation for a return to normal operation.

Heating elements are usually turned off to reduce the temperature, but they are not necessarily extinguished during the entire standby mode of the operating process. Indeed, when the set temperature in standby mode is reached, it may be that the oven 6 must maintain its set temperature in standby mode. The heating elements 7 are then turned on, but generally at a power lower than that which is applied in production mode since the set temperature is lower. Thus, the power of the heating elements 7 of the oven 6 can vary during the same superficial standby period so that the temperature of the oven 6 does not decrease beyond the temperature variation allowed by the setpoint.

When the heating elements 7 of the furnace 6 are electrical resistances, their power can in particular vary with the aid of a dimmer making it possible to modulate the heating power, keeping the resistances on only a part of the time determined according to the power of the heater. desired heating. For example, the resistors can be turned on every second for four tenths of a second and turned off for six tenths of a second. On the other hand, if the heating elements 7 are gas burners, it is possible to directly modulate the power of the burners to vary the heating power.

Preferably, the lowering of the set temperature of the furnace 6 is carried out substantially simultaneously with the speed reduction of at least one air circulation member 8. Generally the lowering of the temperature setpoint of the oven 6 and the speed of at least one air circulation member 8 is operated when the standby mode is engaged. However, these two actions can be performed at different times, in particular, the lowering of the set temperature of the furnace 6 can take place later to the speed reduction of at least one turbine 8.

According to a possible additional feature of the operating method, the superficial standby mode comprises lowering the set temperature of the furnace 6 only if the minimum stopping time of the shrinkwrapper 2 is known.

The minimum duration of the shrinkwrapper is the minimum time during which the shrinkwrapper can not produce, because it does not receive products 3 ready to be shrouded or that it is in maintenance or breakdown. Thus, the superficial standby mode can comprise the reduction of the set temperature of the oven 6 which is operated only if it is possible to appreciate a minimum period before which products will be ready again to be processed by the shrinkwrapper.

For example, such a duration may be known when an operator decides to stop production for a specified period. Such a duration can also be known if there is a breakdown or a problem at any level of the production and packaging line and it is possible to evaluate a minimum duration of treatment. Yet another possibility is that a failure concerns an upstream element and the necessary time (x minutes) for the products 3 to transit from this upstream element to the entrance of the shrinkwrapper is known. In the latter case, even if the time required to resolve the failure is not known, it is known that the products 3 will be ready to be treated again by the shrinkwrapper x minutes after the end of the failure.

As an oven takes a certain time to go down and rise in temperature, the superficial standby mode of the process of the invention preferably comprises the lowering of the set temperature if a minimum duration of stopping of the shrinkwrapper 2 is known. As detailed later, the fact of requiring to know a minimum duration of stopping of the shrinkwrapper 2 to lower the set temperature of the furnace 6, makes it possible to adapt the lowering value according to this duration, so that the oven 6 can again reach its production temperature as soon as possible after the shrinkwrapper is to resume production, preferably at the latest when the shrinkwrapper 2 is again to process products 3, i.e. where products 3 are again ready to be processed by the shrinkwrapper 2 and / or at the moment when the elements placed downstream of the shrinkwrapper 2 can again receive burdens 4. In other words the lowering value is preferably determined so that the temperature of the furnace 6 is not the element preventing the resumption of production. Indeed, when the event causing the cessation of the shrinkwrapper 2 is completed and 3 products are ready to be fardelés and / or burdens 4 ready to be received downstream of the shrinkwrapper, it is preferable that the oven 6 at its set temperature in production mode.

Thus, the operating method advantageously makes it possible to reduce energy consumption while having a slight or even zero impact on the production of an entire production and packaging line 3.

• un organe de transport 9 sur lequel reposent les produits 3 et qui circule à travers le four 6,
• au moins un premier organe de refroidissement 10 destiné à refroidir l'organe de transport 9 pendant son trajet de retour, et
• au moins un deuxième organe de refroidissement 11 destiné à refroidir les fardeaux 4 en sortie du four de rétraction 6 ;

le mode veille superficielle comprenant en outre l'extinction d'au moins un premier organe de refroidissement 10 et/ou d'au moins un deuxième organe de refroidissement 11.According to a possible additional feature of the operating method, the retraction device 1 further comprises:

• a transport member 9 on which the products 3 rest and which flows through the oven 6,
• at least one first cooling member 10 for cooling the transport member 9 during its return journey, and
• at least one second cooling member 11 for cooling the bundles 4 at the outlet of the shrinking furnace 6;

the superficial standby mode further comprising the extinction of at least a first cooling member 10 and / or at least a second cooling member 11.

The transport member 9 used in the present invention is generally a conveyor belt. Such an element has two windings located at the upstream and downstream ends of the carpet. The carpet then circulates in the oven carrying product batches 3. After leaving the oven 6, it deposits the burdens on another surface, then reaches the downstream winding. He then begins his return journey to reach the upstream winding, then carries new batches of products 3 through the oven etc ... Each area of the carpet of the transport member 9, therefore regularly transit in the tunnel shrink 6 and stores heat. For this reason, the retraction device 1 used in the present invention preferably comprises at least a first cooling means 10, which is intended to cool the carpet during its return path, that is to say when it flows between its downstream winding and its upstream winding. This (s) first cooling means (s) 10 are (are) generally under the carpet, more precisely under the lower belt of the carpet, that is to say the portion of the carpet at the return. This is normally one or more fans. In production mode, at least one cooling means 10, preferably all of the cooling means 10 is lit.

In superficial standby mode, at least one first cooling means 10 may be extinguished. Preferably, all the first cooling means 10 are extinguished. In some embodiments, the first cooling means 10 is turned off only momentarily during the superficial standby mode. Thus, if for example the mat overheats, especially when the set temperature of the oven 6 is not lowered during the superficial standby mode, it is possible to relight one or more first (s) means (s) cooling. (s) first means (s) of cooling 10 may for example be automatically switched back on if the mat passes above a certain preset temperature.

The bundles 4 coming out of the shrinkage furnace are generally relatively hot at the outlet of the shrinking furnace 6, which affects the holding of the products 3 by the shrink film. For this reason, the retraction device 1 used in the present invention preferably comprises at least a second cooling means 11, which aims to cool the burdens 4 just after their exit from the oven 6. This is in principle to one or more fans, preferably located above the bundles 4 when they leave the oven 6. Such fans can also be placed on the sides of the bundles 4 when they leave the oven 6. In production mode, at least one cooling means 11, preferably all cooling means 11 is turned on.

When the shrinkwrapper does not produce, burdens 4 do not come out of the oven 6, and it is therefore not necessary to cool them. Thus, in superficial standby mode, at least one second cooling means 11 can be extinguished. Preferably, the set of second cooling means 11 is extinguished.

According to some preferred embodiments, during the superficial standby mode, all the first cooling means 10 and the second cooling means 11 are turned off.

In some cases, the retraction furnace 6 may include a door 18 at its inlet and outlet. According to some embodiments, the surface standby mode can then further include closing these doors 18 to reduce heat loss.

According to a possible additional characteristic of the operating method, the reduction of the speed of at least one air circulation member 8 is carried out substantially simultaneously with the extinction of at least one first cooling member 10 and / or at least one second cooling member 11.

Preferably, when the superficial standby mode is engaged, all the changes made to switch from the production mode to the superficial standby mode are operated substantially simultaneously.

• la température de consigne du four 6 est abaissée d'une valeur prédéfinie par rapport au mode production, et
• l'ensemble des premiers organes de refroidissement 10 et des deuxièmes organes de refroidissement 11 est éteint.

According to a possible additional characteristic of the operating method, during the superficial standby mode, the speed of the assembly 8 air circulation members is reduced to a non-zero value, and, where appropriate:

• the setpoint temperature of the oven 6 is lowered by a predefined value relative to the production mode, and
• all the first cooling members 10 and the second cooling members 11 are extinguished.

• la réduction de la vitesse de l'ensemble des turbines 8 jusqu'à une valeur non nulle,
• l'extinction de l'ensemble des premiers organes de refroidissement 10, et
• l'extinction de l'ensemble des deuxièmes organes de refroidissement 11.

Thus, according to a preferred embodiment, the superficial standby mode comprises:

• reducing the speed of all the turbines 8 to a non-zero value,
• the extinction of all the first cooling members 10, and
• the extinction of all the second cooling members 11.

This embodiment is more particularly implemented when the minimum stopping time of the shrinkwrapper is unknown.

• la réduction de la vitesse de l'ensemble des turbines 8 jusqu'à une valeur non nulle,
• l'extinction de l'ensemble des premiers organes de refroidissement 10,
• l'extinction de l'ensemble des deuxièmes organes de refroidissement 11, et
• l'abaissement de la température de consigne du four 6 d'une valeur prédéfinie.

According to another preferred embodiment, the superficial standby mode comprises:

• reducing the speed of all the turbines 8 to a non-zero value,
• the extinction of all the first cooling members 10,
• the extinction of all the second cooling members 11, and
• lowering the set temperature of the oven 6 by a preset value.

This embodiment is more particularly implemented when the minimum stopping time of the shrinkwrapper is known.

• le mode veille superficielle comprend l'abaissement de la température de consigne du four 6 tel que défini précédemment, et
• le procédé de fonctionnement comprend en outre un mode veille prolongée comprenant l'arrêt de l'ensemble des organes 8 de circulation d'air et éventuellement de l'organe de transport 9, ledit mode veille prolongée étant enclenché lorsque, lors du mode veille superficielle, la température du four 6 baisse jusqu'à atteindre une température seuil prédéfinie.

According to an additional possible feature:

• the superficial standby mode comprises lowering the set temperature of the oven 6 as defined above, and
• the operating method further comprises a prolonged standby mode comprising the stopping of all the air circulation members 8 and possibly the transport member 9, said extended standby mode being engaged when, during the superficial standby mode , the temperature of the oven 6 decreases until reaching a predefined threshold temperature.

Indeed, when the retraction device operates according to the superficial standby mode, the turbines 8 continue to stir air from the oven 6, even if they rotate at a reduced speed compared to the production mode. This makes it possible to cool the heating blocks 7 to prevent their deterioration. However, when the superficial standby mode further comprises lowering the temperature setpoint of the oven 6 relative to the production mode, the heating blocks 7 are in principle off to allow the oven 6 to go down in temperature. Thus, if the set temperature is sufficiently low, after a certain time of lowering temperature, the heating blocks 7 are cold enough to no longer need to be cooled by the air circulation members 8.

Therefore, in certain embodiments, a threshold temperature, lower than the set temperature of the furnace 6 in production mode but greater than the set temperature in standby mode, is set so that the turbines 8 are extinguished when the temperature oven 6 reaches this threshold temperature, thereby engaging the mode called hibernation mode. The method can thus include the transition from production mode to superficial standby mode, then the transition from superficial standby mode to hibernation mode. On the other hand, the method preferentially does not include a direct transition from the production mode to the hibernation mode because there would be a risk of damaging the heating blocks 7. Preferably, the turbines 8 are turned off automatically when the oven 6 reaches the threshold temperature.

Typically, the threshold temperature is around 100 ° C, while the operating temperature of the furnace 6 in production mode is of the order of 200 ° C. Thus, if the set point temperature of the oven in superficial standby mode is less than 100 ° C., for example 80 ° C., when the oven goes down to temperature and reaches the threshold temperature, around 100 ° C., the hibernation mode is engaged, in particular, automatically, thus causing the shutdown of the turbines 8.

The activation of the hibernation mode generates an additional saving of energy because there is no more energy consumed for the operation of the turbines 8. In addition, the stirring of the air of the oven 6 being stopped, the oven continues to lower in temperature but more slowly, which allows to better preserve the heat in the oven for a subsequent return in production mode. In other words, for an identical duration of operation in superficial standby mode and in hibernate mode, the oven loses more heat in the super standby mode. Therefore, when returning to production mode, less power and less time will be required to allow the oven to reach operating temperature again in production mode if the hibernation mode is engaged.

According to some embodiments, the hibernation mode of the operating method further comprises stopping the transport member 9 or at least a significant decrease in its speed. Thus, the hibernation mode can cause the extinction of all the turbines 8 and the interruption of the transport member 9.

When the retraction device 1 operates in hibernation mode, a return to production mode is preferably effected via a transition to superficial standby mode. Indeed, before raising the oven 6 in temperature, and therefore, to turn on the heating blocks 7, it is preferable to run the turbines again 8 to prevent the heating blocks 7 from overheating. Thus, the method may include switching from hibernation mode to superficial sleep mode, and then switching from superficial standby mode to production mode. On the other hand, the method preferably does not include a direct transition from the hibernate mode to the production mode.

• une température de consigne en mode production qui correspond sensiblement à la température que doit avoir le four 6 pour produire, et
• une température de consigne en mode veille qui correspond à la température jusqu'à laquelle le four 6 peut descendre en mode veille superficielle, et, le cas échéant, en mode veille prolongée.

Autrement dit, la température de consigne appliquée au four 6 ne diffère généralement pas selon que le dispositif de rétraction soit en mode veille superficielle ou prolongée.In general, whether or not the method comprises a hibernation mode, two different setpoint temperatures can be applied to the oven 6, namely:

• a set temperature in production mode which corresponds substantially to the temperature that the furnace 6 must have to produce, and
• a set temperature in standby mode which corresponds to the temperature up to which the oven 6 can go down in superficial standby mode, and, if necessary, in hibernation mode.

In other words, the set temperature applied to the oven 6 does not generally differ according to whether the retraction device is in superficial or prolonged standby mode.

According to a possible additional feature of the operating method, the retraction device 1 returns to superficial standby mode from the hibernation mode when the oven 6 reaches the setpoint temperature of the standby mode.

Indeed, when the oven 6 reaches the set temperature in standby mode, it must not continue to go down in temperature. It is therefore necessary to turn on the heating blocks 7 to maintain the temperature of the oven 6. However, to avoid damaging the heating blocks 7, it is preferable that the air is ventilated in their vicinity. For this reason, the stirring of the air is triggered before the ignition of the heating blocks 7. Still in a desire to optimize the energy consumption of the retraction device 1, the brewing is certainly restarted, but the intensity corresponding to that of the superficial standby mode.

Thus, when the method operates in the hibernate mode, and the oven 6 reaches the setpoint temperature of the standby mode, the turbines 8 are restarted at their operating speed in superficial standby. If the transport member 9 has also been slowed down, or even stopped during the hibernation mode, it is returned to its operating speed in production mode, preferably at the same time as the turbines 8, in order to avoid that it overheated. The return of the hibernation mode to the superficial standby mode can for example be switched on automatically when the oven 6 reaches its set temperature in standby mode.

• le four 6 a atteint sa température de consigne en mode production,
• l'ensemble des premiers organes de refroidissement 10 sont allumés, et
• l'ensemble des deuxièmes organes de refroidissement 11 sont allumés.

When leaving the superficial standby mode to return to production mode, the shrinkwrapper 2 can again function when all the turbines 8 operate at their production speed, and if necessary, when:

• the oven 6 has reached its set temperature in production mode,
• all the first cooling members 10 are lit, and
• all the second cooling members 11 are on.

Among these various parameters, the delivery of the turbines 8 to their production speed and the ignition of the first and second cooling means 10, 11 are instantaneous or almost instantaneous. On the other hand, the oven 6 takes a certain time to reach its production temperature again. For this reason, in order to save more energy, when returning to production mode, the parameters modified when starting the surface standby can be put back into production mode at different times.

Thus, when the temperature setpoint of the oven 6 has not been lowered during the superficial standby mode, the parameter (s) modified (s) during the setting in superficial standby mode, are preferably returned to production mode , substantially simultaneously, generally when products 3 are again ready to be processed by the shrinkwrapper 2.

On the other hand, when the set temperature of the oven 6 has been lowered during the superficial standby mode, the delivery of the oven temperature setpoint 6 to its value in production mode is preferably the first parameter to be put back into production mode, in order to optimize the energy saving.

• le mode veille superficielle comprend l'abaissement de la température de consigne du four 6 tel que défini précédemment, et
• le dispositif de rétraction 1 retourne en mode production à partir du mode veille superficielle, via au moins les étapes successives suivantes :
  1. (i) remise de la température de consigne du four 6 à sa valeur en mode production,
  2. (ii) remise de la vitesse de l'ensemble des organes 8 de circulation d'air à sa vitesse de fonctionnement en mode production et, le cas échéant, remise en marche des premier(s) et/ou deuxième(s) organes de refroidissement 10,11,

l'étape (ii) intervenant de préférence une fois que le four 6 a atteint sa température de fonctionnement en mode production.Thus, according to a possible additional characteristic of the operating method:

• the superficial standby mode comprises lowering the set temperature of the oven 6 as defined above, and
• the retraction device 1 returns to production mode from the superficial standby mode, via at least the following successive steps:
  1. (i) returning the set temperature of furnace 6 to its value in production mode,
  2. (ii) restoring the speed of all the air circulation members 8 to its operating speed in production mode and, if necessary, restarting the first and / or second organs of cooling 10,11,

step (ii) preferably taking place once the oven 6 has reached its operating temperature in production mode.

In this way, a saving of energy is advantageously achieved at the level of the turbines 8 and, where appropriate, at the level of the first and second cooling means 10, 11 while the oven 6 rises in temperature.

In cases where the superficial standby mode comprises closing doors 18 disposed at the inlet and the outlet of the oven 6, step (ii) then generally comprises the reopening of these doors.

According to a possible additional feature of the operating method, when returning to production mode from the surface standby mode, the set of air circulation members 8 is returned to its operating speed in production mode and, if necessary, the set of first and second cooling members 10,11 is restarted, this (these) action (s) being performed (s) at the latest when the shrinkwrapper 2 is to process products 3.

• des produits 3 sont à nouveau prêts à être traités par la fardeleuse 2, c'est-à-dire lorsque des produits 3 arrivent au niveau de la fardeleuse 2, et/ou
• les éléments placés en aval de la fardeleuse 2 peuvent à nouveau recevoir des fardeaux 4, c'est-à-dire absorber le flux de fardeaux 4 sortant de la fardeleuse 2.

In other words, the turbines 8 and, if appropriate, the first (s) and second (s) cooling means 10,11 are returned to production mode at the latest when:

• products 3 are again ready to be processed by the shrinkwrapper 2, that is to say when products 3 arrive at the level of the shrinkwrapper 2, and / or
• the elements placed downstream of the shrinkwrapper 2 can again receive burdens 4, that is to say absorb the flow of bundles 4 coming out of the shrinkwrapper 2.

Even more preferably, the turbines 8 and the cooling means 10, 11 are returned to production mode when the shrinkwrapper 2 has to process products 3.

Thus, in the case where the set temperature of the oven 6 is lowered in superficial standby mode, the return to production mode is preferably started before the shrinkwrapper 2 is ready for operation again. At first, the set temperature of the oven 6 is then raised to the production temperature. Preferably, the turbines 8 and, if appropriate, the first and second cooling means 10, 11 are then returned to production mode when the furnace 6 has reached the production temperature, and still more preferably when products 3 are ready to be produced. processed by the shrinkwrapper 2.

• le mode veille superficielle comprend l'abaissement de la température de consigne du four 6 alors que la durée minimum d'arrêt de la fardeleuse 2 est connue tel que défini précédemment, et
• lors du retour en mode production à partir du mode veille superficielle, la température de consigne du four 6 est remise à sa température de fonctionnement en mode production au plus tard au moment permettant au four 6 d'être à cette température lorsque la fardeleuse 2 doit traiter des produits 3.

According to an additional possible characteristic of the operating method:

• the superficial standby mode comprises lowering the set temperature of the oven 6 while the minimum duration of stopping of the shrinkwrapper 2 is known as defined above, and
• when returning to production mode from the superficial standby mode, the set temperature of the oven 6 is returned to its operating temperature in production mode at the latest at the time allowing the oven 6 to be at this temperature when the shrinkwrapper 2 must treat products 3.

To do this, it is necessary to know the minimum duration of stop of the shrinkwrapper 2. In fact, in this case it is possible to anticipate by determining when to start to raise the furnace 6 in temperature for that it can reach its production temperature at the latest when products 3 are again ready to be treated by the shrinkwrapper 2 and / or when the elements placed downstream of the shrinkwrapper 2 can again receive burdens 4. Indeed the rate at which a furnace heats up is one of these characteristics. Knowing this characteristic, a person skilled in the art can determine when to change the temperature setpoint so that the oven 6 reaches its production temperature at the latest when the shrinkwrapper 2 must again treat products 3. Such a mode of operation is particularly advantageous since the standby mode does not generate any impact on the production of the entire line. Indeed, the retraction device 1 is in production mode at the latest when products 3 are ready to be fardelés and / or when new burdens 4 can be received downstream, thanks to an anticipation of the delivery of the temperature of oven setpoint 6 to its production value.

Even more preferably, especially when the stopping time of the shrinkwrapper 2 is known, the furnace 6 reaches its set temperature in production mode at the moment when the products 3 are again ready to be processed by the shrinkwrapper 2. In this case, In this case, the energy saving is optimal since the retraction device 1 is in production mode only when it has to produce.

As indicated above, the lowering value of the set temperature of the oven 6 in the superficial standby mode can be adapted according to the minimum duration of the end of the shrinkwrapper 2 so that the oven 6 can reach its production temperature again. at the latest when the shrinkwrapper 2 must again treat products 3. This value is therefore determined according to the speed at which the oven 6 descends and rises in temperature, and according to the minimum stopping time of the shrinkwrapper 2 .

For example, the following two scenarios may occur. Firstly, we can be aware of an event preventing the shrinkwrapper 2 from operating for a certain minimum time, for example ten minutes. In this case, the temperature setpoint in superficial standby mode will be calculated so that the oven 6 can go down in temperature until reaching the lowered setpoint and then go back to temperature to reach the production temperature again, at the expiration of this minimum duration. Second, we can have knowledge of a minimum necessary time, for example three minutes, so that products 3 can again arrive at the shrinkwrapper 2, once an incident occurring upstream of the shrinkwrapper 2 is set. In this case, the temperature setpoint in the standby mode will be adjusted to a value such that the oven 6 can go from the setpoint temperature in standby mode to the production temperature in the time required for the products 3 to join the shrinkwrapper 2 from the scene of the incident, namely, three minutes here. Oven 6 will therefore be maintained at its set temperature in standby mode until the incident is set. At this time only, the set temperature of the oven 6 will be returned to its production value.

The invention also relates to a device configured to implement the method as described above.

• un four 6 de rétraction comprenant au moins un organe de chauffage 7 destiné à chauffer l'air du four 6 et au moins un organe 8 de circulation d'air destiné à répartir l'air chaud dans le four 6 ; et
• un organe de commande 15 configuré pour recevoir au moins un signal de mise en mode veille superficielle ou de retour en mode production et enclencher le mode correspondant au signal reçu ;

ledit dispositif 1 étant configuré pour que lors du mode veille superficielle, la vitesse d'au moins un organe 8 de circulation d'air soit réduite par rapport au mode production, jusqu'à une valeur non nulle.In particular, it may be a retraction device 1 of an automatic shrinkwrapper 2 intended to be used in a processing facility of products 3 delivered in the form of bundles 4, each grouping together several products 3 held together with each other. using a shrink film 5; said device 1 being configured to operate at least in a production mode in which the shrinkwrapper 2 is set to produce or a superficial standby mode conducive to energy saving, said device 1 comprising at least:

• a shrinkage oven 6 comprising at least one heating member 7 for heating the air of the oven 6 and at least one air circulation member 8 for distributing the hot air in the oven 6; and
• a controller 15 configured to receive at least one superimposed standby mode signal or return to production mode and engage the mode corresponding to the received signal;

said device 1 being configured so that during superficial standby mode, the speed of at least one air circulation member 8 is reduced compared to the production mode, to a non-zero value.

Thus, the device 1 comprises a control member 15 able to operate said device 1 in the desired mode. More specifically, during a change in the operating mode of the device 1, it receives a signal, for example putting in superficial standby mode and then activates the mode corresponding to this signal, namely the superficial standby mode. In the same way, if it receives a return signal in production mode, it then triggers the return to production mode.

In addition, when the operating method includes a hibernation mode, the device 1 can also be configured to receive a signal for hibernation or return to superficial standby mode and engage the mode corresponding to the received signal. Thus, if it receives a signal to put in hibernation mode, it triggers the hibernation mode, and if it receives a return signal in superficial standby mode, it triggers the return to superficial standby mode.

As represented in figure 2 such a controller 15 comprises a memory 16 and a processor 17. The memory 16 can store the instruction code which is readable and executable by the processor 17. The instruction code stored in the memory 16 may be the form of a computer program, which, when executed by the processor 17 operates the device 1 according to the operating method described above.

In the embodiment illustrated in figure 1 attached, an automatic shrinkwrapper 2 is shown. Groups of products 3 arrive at the entrance of the shrinkwrapper 2 and come out in the form of 4 self-supporting bundles. In a first step, the product groups 3 enter a zone 14 in which they are coated with a heat-shrinkable film 5.

• un four de rétraction 6 destiné à rétreindre le film 5 enrobé autour de chaque lot de produits 3, du fait de la chaleur de l'air au sein de ce four 6. Typiquement, la température se situe autour de 200°C ;
• un organe de transport 9 qui peut être le même que celui qui transporte les produits 3 dans la zone 14 ou non. Cet organe de transport 9 est de préférence un convoyeur à tapis. Il conduit les lots de produits 3 à travers le four de rétraction 6, c'est-à-dire qu'il commence avant le four 6 et se termine après ;
• des premiers organes de refroidissement 10 destinés à refroidir le tapis de l'organe de transport 9 sur son trajet de retour, c'est-à-dire son trajet qui va de la sortie du four 6 vers son entrée. Ces premiers organes de refroidissement 10 permettent d'éviter au tapis d'emmagasiner trop de chaleur et sont situés sous l'organe de transport 9. Il s'agit généralement de ventilateurs. Sur la figure 1, ces premiers moyens de refroidissement sont au nombre de trois mais il peut très bien n'y en avoir qu'un ou deux ou encore, un nombre supérieur à trois comme quatre ou cinq par exemple ; et

• des deuxièmes organes de refroidissement 11 destinés à refroidir les fardeaux 4 en sortie du four 6. Ces deuxièmes organes de refroidissement 11 permettent plus précisément de refroidir le film 5 et donc d'assurer un meilleur maintien des produits 3 au sein d'un fardeau 4. Ils sont généralement situés juste au-dessus des fardeaux 4 qui sortent du four 6. Il s'agit généralement de ventilateurs. Sur la figure 1, ces deuxièmes moyens de refroidissement sont au nombre de trois mais il peut très bien n'y en avoir qu'un ou deux ou encore, un nombre supérieur à trois comme quatre ou cinq par exemple.

The product groups 3 wrapped in a film 5 then reach the retraction device 1 according to the present invention. The retraction device 1 of the shrinkwrapper 2 shown in FIG. figure 1 includes at least:

• a retraction furnace 6 for shrinking the wrapped film 5 around each batch of products 3, because of the heat of the air within the furnace 6. Typically, the temperature is around 200 ° C;
• a transport member 9 which may be the same as that which carries the products 3 in the zone 14 or not. This transport member 9 is preferably a conveyor belt. He drives the batches of products 3 through the retraction furnace 6, that is to say that it begins before the furnace 6 and ends after;
• first cooling members 10 for cooling the carpet of the transport member 9 on its return path, that is to say its path from the furnace outlet 6 to its inlet. These first cooling members 10 prevent the carpet from storing too much heat and are located under the transport member 9. These are generally fans. On the figure 1 , these first means of there are three of them, but there may very well be only one or two, or a number greater than three, for example four or five; and

• second cooling members 11 for cooling the loads 4 at the furnace outlet 6. These second cooling members 11 allow more precisely to cool the film 5 and thus to ensure better maintenance of the products 3 within a burden 4 They are usually located just above the burdens 4 that come out of the oven 6. These are usually fans. On the figure 1 these second cooling means are three in number, but there may very well be only one or two or a number greater than three, for example four or five.

The retraction furnace 6 represented in figure 1 comprises two modules separated by a wall 13. However devices comprising ovens 2 comprising 1 to 5 modules or more, are part of the present invention. In the oven 6 of the figure 1 each module comprises at least one heating member 7 for heating the air of the oven 6 and at least one turbine 8 for stirring the (hot) air so as to allow an optimal formation of a necking around each batch of products 3.

The operating method according to the invention comprises at least two modes of operation, namely a superficial standby mode and a production mode, these two modes differing from each other by the settings applied to the retraction device 1. In general, the production mode is implemented when the shrinkwrapper produces while the superficial standby mode is implemented when the shrinkwrapper is prevented from producing. Turning on the superficial standby mode saves energy.

• au moins un, voire l'ensemble des premiers moyens de refroidissement 10 peut être éteint ;
• au moins un, voire l'ensemble des deuxièmes moyens de refroidissement 11 peut être éteint ; et
• la consigne de température du four 6 peut être abaissée.

Thus, during the production mode, the turbines 8, the cooling means 10, 11 have specific operating parameters and the oven air is at its set temperature in production mode. In superficial standby mode, at least one of these parameters is modified namely, the speed of rotation of at least one turbine 8 of the furnace 6, preferably of all the turbines 8. Thus, in superficial standby mode, the turbines 8 operate at a reduced speed compared to the production mode. In addition, in superficial standby mode:

• at least one or all of the first cooling means 10 can be extinguished;
• at least one or all of the second cooling means 11 may be extinguished; and
• the temperature setpoint of the oven 6 can be lowered.

The superficial standby mode may also include the closing of the inlet and outlet doors 18 of the oven 6, when it is equipped with such doors.

Preferably, during the superficial standby mode, each of the turbines 8 operates at a reduced speed and each of the first and second cooling means 10, 11 is turned off. When the superficial standby mode is activated, these modifications are made substantially simultaneously. These elements being modifiable instantaneously or almost, when returning to production mode, these settings are returned to production mode, substantially simultaneously, and preferably at the latest, when the element that prevented the wrapping machine 2 from producing is completed and that products 3 arrive at the level of the shrinkwrapper 2, ready to be treated. Even more preferably, these settings are returned to production mode, when products 3 are again at the level of the shrinkwrapper 2 ready to be processed.

According to some embodiments, the superficial standby mode further comprises lowering the set temperature of the oven 6. Unlike the other parameters described above, there is a lag between the time when the set temperature is lowered and the moment when the oven 6 actually reaches the set temperature. For this reason, this parameter is preferably modified in superficial standby mode if a minimum duration of shutdown of the shrinkwrapper 2 is known. Then, in this case, as the speeds at which an oven descends and rises in temperature are part of the known characteristics of an oven, it is possible to set a set temperature of the oven 6 in standby mode so that the oven 6 has the time to reach again its temperature of production at the latest when products 3 arrive again at the level of the shrinkwrapper 2, ready to be fardelés. Thus, the superficial standby mode advantageously has no impact on the production of the line.

• dans un premier temps, la consigne de température du four 6 est remise à la consigne de production. Ceci est effectué de préférence suffisamment tôt pour que le four 6 atteigne sa température de consigne au plus tard lorsque des produits 3 sont à nouveau disposés à être fardelés ;
• dans un deuxième temps, les turbines 8 sont remises à leur vitesse de production, et les organes de refroidissement 10,11 sont remis en marche. Ceci est de préférence effectué au dernier moment, lorsque la fardeleuse redémarre.

Moreover, in order to optimize the energy saving, when the superficial standby mode furthermore comprises lowering the setpoint temperature of the oven 6, the delivery of the various settings in production mode is preferentially done in the following order :

• initially, the temperature setpoint of the oven 6 is returned to the production setpoint. This is preferably done sufficiently early so that the oven 6 reaches its set temperature at the latest when products 3 are again ready to be fardelés;
• in a second step, the turbines 8 are returned to their production speed, and the cooling members 10,11 are restarted. This is preferably done at the last moment, when the shrinkwrapper restarts.

• le mode veille superficielle comprend l'abaissement de la température de consigne du four 6 ; et
• lorsque la valeur d'abaissement de la température de consigne est suffisamment importante pour que, lors de la descente en température du four 6, il passe en dessous d'une certaine température appelée température seuil se situant généralement autour de 100°C.

In some embodiments, the method of operation further includes a sleep mode. This hibernation mode can be implemented when:

• the superficial standby mode includes lowering the set temperature of the oven 6; and
• when the lowering value of the set temperature is large enough that, during the lowering temperature of the furnace 6, it falls below a certain temperature called threshold temperature generally around 100 ° C.

The retraction device 1 is then set to go, in particular automatically, from the superficial standby mode to the hibernation mode when the oven 6 goes down in temperature and reaches the threshold temperature. The hibernation mode comprises the extinction of all the turbines 8, and possibly the slowing down of the speed of the transport member 9, or even stopping.

In practice, the implementation of the hibernation mode takes advantage of the fact that when the oven 6 passes below a certain temperature, it is no longer necessary to cool the heating blocks 7 and possibly the transport member 9. Indeed, when the temperature in the oven 6 drops in temperature until reaching the threshold temperature, the heating blocks 7 have been stopped for some time and the transport member does not store much of heat as it passes through the oven 6.

When the oven 6 then reaches its setpoint temperature in standby mode (which is lower than the threshold temperature) it must not fall below this temperature. It is therefore necessary to heat the oven 6 again, at least to keep the oven 6 at its set temperature in standby mode. The retraction device 1 is therefore programmed to switch back to superficial standby mode at this point. at this point, starting with the turbines 8 again, at their operating speed in superficial standby mode. If the transport member 9 was stopped in hibernation mode, it is restarted at that time preferably. Once the turbines 8 are in operation, the heating blocks 8 are turned on to maintain the oven 6 at its set temperature in standby mode or to reach the operating setpoint in production mode if a return to production mode is desired at this time. the.

In the embodiment illustrated in figure 2 attached, the management of the operating modes of a retraction device 1 is shown. Thus, as specified below, the device 1 comprises a control member 15 able to operate said device 1 in the desired mode (production mode, super standby mode or possibly extended standby mode). The control member 15 can then comprise a memory 16 and a processor 17. The memory 16 can store an instruction code which is readable and executable by the processor 17.

In order to initiate the desired operating mode, the control member 15 may be connected to all the elements of the retraction device 1 may be modulated during operation of the device 1 in order to control these elements. Thus, the control member may be connected to the heating elements 7, to the air circulation members 8, to the transport member 9, to the first and second cooling members 10, 11 and, where appropriate, to the doors 18 disposed at the inlet and the outlet of the oven 6.

Thanks to the invention, it is thus possible to save energy significantly within a production and packaging line when the retraction device 1 is not in operation, via the passage of the production mode. in superficial sleep mode, then eventually in hibernation mode. This energy saving is based both on a direct reduction of consumption via the slowing down or even the extinction of certain elements and on an indirect saving via a better heat preservation allowing the retraction device 1 to consume less energy. to return to production mode. In addition, the solution developed in the present invention also has the advantage of having little or no influence on the production of the entire line, particularly in terms of flow. Indeed, at the end of a standby phase, the return to production mode is anticipated so that the retraction device 1 can preferably operate as soon as products 3 are again ready to be fardelés.

Although the description above is based on particular embodiments, it is in no way limiting to the scope of the invention, and modifications may be made, in particular by substitution of technical equivalents or by a different combination of all or some of the features developed above.

Claims (13)

Method of operating a shrink device (1) of an automatic shrinkwrapper (2) for use in a processing plant of products (3) delivered in the form of bundles (4), each grouping several products (3) held together by a shrink film (5); said retraction device (1) being provided with a shrinkage furnace (6) comprising at least one heating member (7) for heating the furnace air (6) and at least one circulation member (8) for air for distributing hot air in the oven (6); said method of operation comprising a production mode in which the shrinkwrapper (2) is set to produce and a superficial standby mode, conducive to energy saving;
characterized in that
the superficial standby mode comprises reducing the speed of at least one air circulation member (8) relative to the production mode to a non-zero value. Method according to claim 1, characterized in that
the superficial standby mode furthermore comprises lowering the setpoint temperature of the oven (6) by a preset value with respect to the production mode to a so-called setpoint value in standby mode, said lowering of the set temperature being preferably carried out substantially simultaneously with the speed reduction of at least one air circulation member (8). Method according to the preceding claim, characterized in that
the superficial standby mode includes lowering the setpoint temperature of the oven (6) only if the minimum duration of stopping of the shrinkwrapper (2) is known. Method according to one of the preceding claims, characterized in that
the retraction device (1) further comprises a transport member (9) on which the products (3) rest and which circulates through the oven (6), at least a first cooling member (10) for cooling the transport member (9) during its return journey and at least a second cooling member (11) for cooling the bundles (4) at the outlet of the retraction furnace (6); the superficial standby mode further comprising the extinction of at least one first cooling member (10) and / or at least one second cooling member (11). Method according to the preceding claim, characterized in that
the reduction of the speed of at least one air circulation member (8) in the superficial standby mode is carried out substantially simultaneously with the extinction of at least a first cooling member (10) and / or from minus a second cooling member (11). Method according to any one of the preceding claims,
characterized in that during the superficial standby mode the speed of the set of air circulation members (8) is reduced to a non-zero value, and, where appropriate: the setpoint temperature of the oven (6) is lowered by a predefined value relative to the production mode, and the set of first cooling members (10) and second cooling members (11) is extinguished. Method according to one of the preceding claims, characterized in that
during the superficial standby mode, the speed of at least one air circulation member (8) is reduced to a value ranging from 10 to 90%, preferably from 30 to 80%, in particular from 50 to 70%; % of speed in production mode. Process according to one of Claims 2 to 7, characterized in that
the superficial standby mode comprises lowering the set temperature of the oven (6) as defined in claim 2, and
said operating method further comprises a prolonged standby mode comprising stopping all the air circulation members (8) and possibly the transport member (9), said extended standby mode being engaged when, during from the superficial standby mode, the oven temperature (6) decreases until a preset threshold temperature is reached. Method according to the preceding claim, characterized in that
the retraction device (1) returns to superficial standby mode from the prolonged standby mode when the oven (6) reaches the setpoint temperature of the standby mode. Process according to one of Claims 2 to 9, characterized in that
the superficial standby mode comprises lowering the set temperature of the oven (6) as defined in claim 2, and
the retraction device (1) returns to production mode from the superficial standby mode, via at least the following successive steps: (i) returning the set temperature of the furnace (6) to its value in production mode, (ii) restoring the speed of all the air circulation members (8) to its operating speed in production mode and, if necessary, restarting the first (s) and / or second (s) cooling members (10,11), step (ii) preferably taking place once the furnace (6) has reached its operating temperature in production mode. Process according to one of Claims 3 to 10, characterized in that
the superficial standby mode comprises lowering the set temperature of the oven (6) while the minimum stopping time of the shrinkwrapper (2) is known as defined in claim 3, and
when returning to production mode from the superficial standby mode, the set temperature of the oven (6) is returned to its operating temperature in production mode at the latest at the moment allowing the oven (6) to be at this temperature when the shrinkwrapper (2) has to process products (3). Method according to one of the preceding claims, characterized in that
when returning to production mode from the superficial standby mode, all the air circulation members (8) are returned to their operating speed in production mode and, if necessary, all the first (s) and second (s) cooling members (10,11) is restarted, this (these) action (s) being performed (s) at the latest when the shrinkwrapper (2) must treat products (3). Device for retraction (1) of an automatic shrinkwrapper (2) for use in a product treatment plant (3) delivered in the form of bundles (4) which each group together several products (3) held together by means of a shrink film (5); said device (1) being configured to operate at least in one production mode in which the shrinkwrapper (2) is set to produce or a superficial standby mode conducive to energy saving, said device (1) comprising at least: - a shrink oven (6) comprising at least one heating member (7) for heating the air of the oven (6) and at least one air circulation member (8) for distributing the hot air in the oven (6); and a control member (15) configured to receive at least one superimposed standby mode signal or to return to production mode and switch on the mode corresponding to the received signal; said device (1) being configured so that during the superficial standby mode, the speed of at least one air circulation member (8) is reduced compared to the production mode, to a non-zero value.

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