readily available, it was clear to the company’s engineering team that the legacy drives and control system for the machine was becoming increasingly obsolete with reliability issues and reduced line availability becoming more of a problem. The decision was made to seek the best solution that would not only address this, but at the same time enable the company to upscale throughput of bottle numbers the machine could process, supporting operational efficiency objectives.
The labelling function operates as a rotary machine applying the labels to glass bottles housing the Chivas Brothers whisky. Incoming bottles are consistently spaced and passed into a star wheel which orientates them. The star wheel loads each bottle onto one of 16 plates that are mounted on a central platform. The platform rotates presenting each plate to one of three labelling stations in turn. The bottles must be orientated to angular positions as the machine rotates to wipe the bottle with brushes and to present it to the labelling station in the correct orientation. Having travelled past all three labelling stations the bottles are unloaded by another starwheel. Machine throughput is typically in the range of 100 – 130 bottles per minute with a maximum speed of 150 bottles per minute. As a result of assessing the upgrade of the machine’s control system, the company was also seeking to improve this throughput level.
To address the operational efficiency and reliability issues, Siemens and HMK proposed use of Siemens Simotion D445-1 to provide the motion control solution, together with a Profinet interface to the labelling machine’s main PLC, using wireless Scalance components. Due to space constraints in the machine turret, 16 sets of PM340 and CUA31 were specified alongside the Simotion motion control and Sinamics CU320-2 drives. In addition, a DRIVE-CLIQ external encoder was mounted to the roof of the turret to provide absolute position referencefor the rotating table.
Motion Control in Action
In the new control scenario, Simotion motion control receives motion profile parameters from the PLC. These are inthe form of Master Start, Master Finish and Slave Target positions. This data is used to calculate a Simotion camusing user code. Each segment of the cammust move the slave axes to the target position while the master encoder axis moves from the start to finish positions.
Now the upgrade has taken place, Chivas Brothers are benefitting from a number of efficiency improvements that under pin the bottle labelling function. From a diagnostics point of view, it was acknowledged that the previous system provided a low level of feedback for the production team to fault find. The upgrade has significantly enhanced the level of information available, with the new system providing individual drive status information as well as Sinamics and Simotion fault codes so problems can be easily identified and rectified without undue delay. This has been enhanced through the use of an MP277 8 inch HMI, which replaced the original system’s LCD black/white display.
One of the key objectives for the machine upgrade was to enable an improvement in the machine’s throughput performance levels. To help this, HMK wrote and developed software to assess the cam and identify the cam segment that caused the most significant change in the slave position. By altering the master positions by only a single degree, it became clear the dynamic requirements on the slave could be significantly reduced – making it possible to run the labelling machine at a faster rate and increase the bottle throughput efficiencies.
A marked increase in reliability has also been achieved as a result of the upgrade. The original system used sliprings to carry RS485 communication signals to and from the drives. The slip rings were prone to collecting dirt and wearing out which were causing issues. The upgrade has solved this problem by utilising wireless communication between the PLC in the main control cabinet and the Simotion in the turretthrough Profinet over Scalance wireless devices.
Finally,the previous problem of spares availability has been overcome through the useof the Sinamics range of parts which is near the beginning of its lifecycle.This ensures future spares availability will not be an issue for Chivas Brothers for a considerable period of time.
GerryMcManus, project engineer at Chivas Brothers, believes the machine upgrade and the introduction of the new drives and control system from HMK and Siemens has delivered real benefit. He says: “We wanted to address concerns around reliability of the labelling machine, which was becoming increasingly problematic for us. In addition, we also wanted to improve our overall efficiencies so the machine could cope with increased throughput in terms of bottle numbers per minute. I am delighted to say both objectives have been met. Downtime for the machine has been reduced, while we have been able to increase bottle throughput.
“As well as these tangible measures of improvement, operation of the machine is far easier with clear visualisation of the operation via the HMI screens and the ability to quickly spot any problems and rectify them speedily to get the labelling machine running again.”