The Language of Packaging Machinery
Automatic packaging machinery needs to communicate, between components and even between machines, to ensure that the process remains efficient and reliable. The type of communication used will depend in part on the machine in question and the line as a whole. Below are some of the most common machines found on a packaging line and a brief description of how the communication works.
Most automatic rinsing machines will invert containers to wash out the interior of the bottles with air, water or other liquid. Rinsing machines use a PLC that will communicate with a number of different machine components. Indexing gates will normally be used to position bottles correctly. The PLC will send a signal to tell the entry and exit gates when to open and close. A sensor will also be used to let the PLC know when the correct number of bottles have entered the rinse area. Once bottles are in position, the PLC will then "talk" to the clamp, allowing it to grasp the bottles and invert them over a rinse basin. Other signals from the PLC will start and stop the actual rinse, return the bottles to the conveyor and release the clamp. All of these signals will be entered into the PLC via a touchscreen operator interface - in the form of a delay or duration time - that allows settings for different containers to be stored and recalled with the push of a button.
Automatic filling machines work much like the rinsing machines and also utilize a PLC and a touchscreen interface. A count sensor will again tell the PLC when the correct number of bottles have entered the fill area, and signals will come from the PLC to open and close entry and exit gates for indexing. A slightly different "language" may be used for different filling machines, but generally speaking, signals will be sent from the PLC to either open nozzles, start pumps, dive heads or some combination of all of these and more. Liquid fillers may also use neck grabbers, drip trays or other components to assist the fill. Again, the PLC will "talk" to the bottle filler through signals to put these optional components in to play at the correct time. Like the container cleaners above, the signals can be set and stored for product and bottle combinations for easy recall.
While a majority of capping machines will not use a PLC, they will still use sensors to communicate with the different components of the machine. Of course, the type of capping machine used will depend on the type of closure a packager employs and the type of signals will depend not only on which machine is being used, but also on the bottles being run. Automatic cap delivery systems typically use an elevator, bowl or combination to deliver caps to the bottles through a chute just before the capping process begins. A sensor can be used to tell the cap sorter to pause the delivery of caps when the chute is full. while spindle cappers require a little more hands-on adjustment for different bottles (in the form of easy knobs or hand cranks), some capping machines, such as an automatic chuck capper, will still use a PLC to correctly position bottles, dive heads and tighten caps.
COMMUNICATION BETWEEN MACHINES
In addition to the conversations used to make a single machine function consistently and efficiently, sensors can be used to ensure the entire packaging line functions as one. Anti-bottle back up sensors can be used, for example, to ensure that a bottle jam in one location does not create problems up and down a line. When these sensors see a problem, they signal other machines to pause production. For example, should the capping machine become jammed or experience a spill that requires clean up, the sensor will tell the filling machine to finish the current cycle and then pause filling until the jam is cleared. Rejection stations can also be set up using eyes to ensure that each packaging function is performing as expected. For example, if a bottle does not receive a cap, it can be removed from the main conveyor before it moves to the labeler or other equipment down the line, again stopping potential issues before they start.
The basic communication described above can be modified to fit each and every specific packaging project, including custom manufactured packaging machinery for special projects. To learn more about PLCs, sensors and machine communication, contact a Packaging Specialist at Liquid Packaging Solutions today.