Operation of a retraction device of an automatic bundler

1. Method for operating a retraction device ( 1 ) of an automatic bundler ( 2 ) that is designed to be used in a facility for processing products ( 3 ) that are delivered as bundles ( 4 ) that each group multiple products ( 3 ) held together with a retractable film ( 5 );

the retraction device ( 1 ) being equipped with a retraction furnace ( 6 ) comprising at least one heating unit ( 7 ) that is designed to heat air of the retraction furnace ( 6 ) and at least one air circulation unit ( 8 ) that is designed to distribute heated air in the furnace ( 6 );

the method comprising a production mode configured to produce output of bundles ( 4 ) and a superficial standby mode configured to save energy during a temporary production stop;

wherein

the superficial standby mode reduces a speed of at least one air circulation unit ( 8 ) as compared to production mode, to a non-zero value, the superficial standby mode lowers a setpoint temperature of the furnace ( 6 ) by a predefined value relative to the production mode to a set value in standby mode,

the set value in standby mode being calculated so that the furnace drops in temperature to reach the lowered setpoint temperature and then rises in temperature to reach an operating temperature of the production mode upon expiration of a known minimum stop time,

the known minimum stopping time being a period of time from a beginning of the superficial standby mode to when the products ( 3 ) are again ready to be processed by the bundler ( 2 ).

2. Method according to claim 1 , wherein the superficial standby mode also comprises lowering a setpoint temperature of the furnace ( 6 ) by a predefined value, compared to production mode, to a target value in standby mode.

3. Method according to claim 2 , further comprising an extended standby mode that comprises stopping of all air circulation units ( 8 ), with said extended standby mode being engaged automatically when, during the superficial standby mode, the setpoint temperature of the furnace ( 6 ) is lowered to reach a predefined threshold temperature.

4. Method according to claim 3 , wherein the retraction device ( 1 ) returns to superficial standby mode from extended standby mode when the furnace ( 6 ) reaches the setpoint temperature of the furnace ( 6 ).

5. Method according to claim 2 , wherein

the retraction device ( 1 ) also comprises a transport unit ( 9 ) on which the products ( 3 ) rest

and which travels through the furnace ( 6 ), at least one first cooling unit ( 10 ) that is designed to cool the transport unit ( 9 ) during a return trip, and at least one second cooling unit ( 11 ) that is designed to cool the bundles ( 4 ) at an outlet of the retraction furnace ( 6 ); with the superficial standby mode also comprising turning off at least one first cooling unit ( 10 ) and/or at least one second cooling unit ( 11 ).

6. Method according to claim 2 , further comprising an extended standby mode that comprises stopping of all air circulation units ( 8 ) and the transport unit ( 9 ), with said extended standby mode being engaged when, during the superficial standby mode, the setpoint temperature of the furnace ( 6 ) is lowered to reach a predefined threshold temperature.

7. Method according to claim 1 , wherein

the retraction device ( 1 ) also comprises a transport unit ( 9 ) on which the products ( 3 ) rest and

which travels through the furnace ( 6 ), at least one first cooling unit ( 10 ) that is designed to cool the transport unit ( 9 ) during a return trip, and at least one second cooling unit ( 11 ) that is designed to cool the bundles ( 4 ) at an outlet of the retraction furnace ( 6 );

with the superficial standby mode also comprising turning off at least one first cooling unit ( 10 ) and/or at least one second cooling unit ( 11 ).

8. Method according to claim 7 , wherein reduction in the speed of at least one air circulation unit ( 8 ) in the superficial standby mode is performed simultaneously to the turning off of at least one first cooling unit ( 10 ) and/or at least one second cooling unit ( 11 ).

9. Method according to claim 7 , wherein during the superficial standby mode, the speed of all air circulation units ( 8 ) is reduced to a non-zero value, and:

A setpoint temperature of the furnace ( 6 ) is lowered by a predefined value compared to production mode, and

All of the first cooling units ( 10 ) and second cooling units ( 11 ) are turned off.

10. Method according to claim 7 , wherein

the retraction device ( 1 ) returns to production mode from superficial standby mode, via at least the following successive steps:

(i) Bringing the setpoint temperature of the furnace ( 6 ) back to its value in production mode,

(ii) Bringing the speed of all air circulation units ( 8 ) back to an operating speed thereof in production mode, and, restarting the first and/or second cooling units ( 10 , 11 ).

11. Method according to claim 10 , wherein step (ii) takes place once the furnace ( 6 ) has reached an operating temperature in production mode.

12. Method according to claim 7 , wherein during a return to production mode from superficial standby mode, all air circulation units ( 8 ) are brought back to an operating speed thereof in production mode, and, all of the first and second cooling units ( 10 , 11 ) are restarted, with this (these) action(s) being carried out no later than when the bundler ( 2 ) is to process the products ( 3 ).

13. Method according to claim 1 , wherein during the superficial standby mode, the speed of at least one air circulation unit ( 8 ) is reduced to a value that ranges from 10 to 90% of the speed in production mode.

14. Method according to claim 1 , wherein the setpoint temperature of the furnace ( 6 ) is lowered by a predefined value, compared to production mode, to a target value in standby mode, with said lowering of the setpoint temperature being performed simultaneously to reduction in the speed of at least one air circulation unit ( 8 ).

15. Method according to claim 1 , wherein

during the superficial standby mode, the speed of at least one air circulation unit ( 8 ) is reduced to a value that ranges from 30 to 80% of the speed in production mode.

16. Method according to claim 1 , wherein during the superficial standby mode, the speed of at least one air circulation unit ( 8 ) is reduced to a value that ranges from 50 to 70% of the speed in production mode.

17. Method according to claim 1 , wherein

during a return to production mode from superficial standby mode, the setpoint temperature of the furnace ( 6 ) is brought back to an operating temperature in production mode making it possible for the furnace ( 6 ) to be at the operating temperature when the bundler ( 2 ) is to process the products ( 3 ).