How Vision Systems and Sensors Allow Consistent Automatic Filling
Automatic filling allows your business to prepare products absent constant interaction with a machine operator. But for the liquid filler to achieve this goal sans constant human interaction, a multitude of components must be used to ensure proper bottle movement, bottle placement, and liquid flow. Liquid filling machines use sensors on vision systems to ensure consistent and reliable fills in every bottle run through the machine.
Operators of an automatic filling machine will still have some responsibility, including supplying bulk product, setting up the machine, and monitoring the process for proper function. But using an automatic liquid filler removes the need for an operator to interact with each and every bottle filled. This is achieved by using a PLC, along with vision systems made up of sensors to let the different components of the automatic filler to communicate with one another.
INDEXING SYSTEMS
To ensure automatic filling is consistent, bottles must be precisely and consistently placed under the fill heads. The positioning is done by using an indexing system, which can use pins, screws or other components to achieve the goal. The indexing system will typically use a count eye to send a signal to the PLC to open and close, or start and stop, the indexing component. On pin indexing, for example, a sensor will send a signal to the PLC each time it sees a bottle. This "sight" will work in conjunction with pre-set indexing times to ensure that the entry and exit gates open and close, and stay opened and closed for the precise times, to correctly move bottles in and out of the fill zone, as well as position bottles correctly under the nozzles to receive product without splashes or spills.
NO BOTTLE, NO FILL VISION SYSTEMS
The No bottle, no fill (NBNF) vision system requires a preset number of bottles to be "seen" before a fill cycle can begin. This is a critical part of automatic filling in that by stopping the fill cycle, the sensor ensures that nozzles will not open and dispense product without a container present. Without the NBNF system, packagers would need to shut down the machine to clean up spills each time a bottle was not in place during a fill cycle, disrupting not just the filling process, but the packaging line as a whole. Though a simple system, the no bottle, no fill vision system creates a more efficient packaging machine by ensuring that missing bottles will not create lengthy downtime or clean-up for the operators of the entire packaging line.
ANTI-BOTTLE BACK UP VISION SYSTEMS
Though automatic liquid filling equipment can be used as a standalone machine, more often than not they will be seen in a complete, automated packaging line. So even when the bottle filler is working correctly, it can cause issues on a complete packaging system if a machine malfunctions down the line. For example, if a bottle tips over during capping, creating a jam on the capping machine, the filler can worsen the situation by continuing to fill and release containers down the conveyor system. The anti-bottle back up vision system uses a sensor downstream to look for stalled bottles on the power conveyors. If a bottle sits in front of the downstream sensor for a set period of time, a signal will be sent to the PLC to stop cycling bottles once the current fill cycle is complete. So in our scenario, the automatic filling machine will continue to fill the bottles currently under the nozzles, but then will not release those bottles and start another fill cycle until the jam is cleared on the capping machine, keeping issues with other packaging machinery from compounding and minimizing downtime for the entire line.
OTHER SENSORS
Depending on the type of liquid filler being used, various other sensors may come into play to ensure consistent and reliable bottle filling. Floats in a tank may send a signal to the PLC when product is low, as well as signals to refill the tank or stop refilling the tank. Switches and sensors on piston fillers can help with accuracy by telling the piston when to stop retracting or reentering the cylinder. Drip trays and bottle stabilizers will "talk" to the PLC to learn when to extend and do their job. It is this communication between vision systems, sensors and the PLC that allow automatic filling to take place with limited human interaction. To learn more about sensors, vision systems, and packaging equipment communication, and how your own packaging process can benefit from an automatic liquid filling machine, contact a Filling Specialist at Liquid Packaging Solutions today!