Variable Speed Power Conveyor Systems
The phrase "variable speed" may be somewhat overlooked by those that are using a power conveyor system to move bottles from one packaging machine to another. However, the ability to dial in the speed of the conveyor system helps to add efficiency and reliability to a packaging line as a whole for several reasons.
Of course, packagers are always concerned with output, or meeting production demands, so that speed is always a factor with conveyor systems. But rarely, if ever, will conveyors simply be opened up and run at the fastest speed possible. For one thing, not every packaging machine will run at the same speed. A filling machines may run 80 bottles per minute, while the bottle capper will seal 60 bottles per minute. With the capper being downstream from the filling machine, it seems obvious that bottles on the conveyor system will eventually become backed up at the capping machine, if the filling and capping conveyors run at the same, or full, speed.
So conveyor speed is not always about moving bottles as fast as possible, but rather finding consistency in the packaging line, which may include avoiding stop and go processes and minimizing the chance of bottle jamming, tipping or spilling. Allowing product to continuously flow down the conveyor, even if this means varying conveyor speeds from one machine to the next, is a great way to achieve this consistency. Remember, as to the actual speed of a packaging system when it comes to output, the system will only be as fast as its slowest component. So though exceptions may exist, it will usually not add to the efficiency of a line to fill 80 bottles per minute if the capper, labeler and other downstream equipment cannot achieve that same speed.
For this reason, different sections of the conveyor system will include their own speed controls. These controls may be found on a dedicated controller for some sections of the power conveyor, or they may be incorporated into the control panel or touchscreen of a packaging machine such as an overflow filler or a spindle capper. This allows speeds to be set individually for the different packaging functions with the simple turn of a dial or press of a button.
Bottle sizes can also have an affect on packaging system speed as well. Put simply, a liquid filler will fill an 8 ounce bottle quicker than it will fill a gallon container. Conveyor speeds may need to be adjusted to achieve consistency when bottle sizes are changed over on a packaging line. Dialing in conveyor speeds may seem like a tedious and time consuming task, but the design of the conveyors and the controls makes the process simple. PLC's for automatic machinery allow operators to save recipes that may include conveyor speed. For those sections that use a dedicated controller, a simple dial allows an operator to record the ideal setting for each bottle size and quickly adjust to the necessary speed. In most cases, when all bottle sizes are made available for line testing, the correct settings will be recorded or entered in to the recipes prior to the packager even receiving the machine.
So while faster may seem like it would always be better, finding a speed for each section of conveyor based on the process taking place in that section can lead to better bottle flow. This flow allows consistent output while avoiding back ups, jams and inconsistent performance of the system as a whole. For more information on moving bottles, check out the Conveyors and Turntables section of the Liquid Packaging Solutions website, or for questions on bottle conveyors, contact the LPS team today.