Troubleshooting Inconsistent Fills
Filling machinery, like most packaging equipment, includes wear parts and may require changes in certain settings when different bottles or products are run. The wear of parts or an error in set up, among many other things, can lead to inconsistent fills when the machine begins running production. Though not every cause can be enumerated here, the following are a few of the most common issues leading to inconsistent fills.
1. Machine not level
Many times inconsistent fills, regardless of the fill principle, can simply result from a machine that is not sitting level on the production floor. Given that almost every filling machine includes leveling legs which make adjustments simple, this is one of the first issues to check, especially if the machinery has just been set up or recently been relocated.
2. Loose Connections
Many packagers overlook loose connections on the plumbing for the product pathway simply because they assume liquid will be leaking if the connection is loose. This is not always the case, as air may be slowly seeping in to a line rather than liquid leaking out, which can result in inconsistent fills. After checking that the machine is level, operators should check all plumbing connections to ensure that no air is entering the lines.
3. Spacers, Seals or Springs
For those packagers using the popular overflow filling machine, which fills to a level rather than by volume, several different wear parts can be the reason for an inconsistent fill. Operators should check that the spacers used on each nozzle are the same, again especially after a changeover. Nozzle seals can also wear over time, and a bad seal over the bottle opening may lead to an inconsistent fill on an overflow filler. Finally, though rare, springs may lose tension over time, again affecting the seal and dive, which in turn can affect the fill. Operators should check each of these parts on the overflow nozzle and replace worn parts as necessary.
4. Back Pressure
Back pressure can also be an issue on the overflow filler. These machines typically recirculate product back to the tank when it overflows from the bottles being filled. If the return tubing becomes submerged or blocked for any reason, back pressure can affect the filling process resulting, once again, in inconsistent fills. Operators of overflow fillers should be able to easily check the return tubes for issues and clear the tubes if necessary.
5. Individual Fill Times
For volumetric filling machines, and specifically gravity filling machines, individual fill heads can be set to different times to more accurately reach volumetric targets. Product flow through the pathway can actually result in different ideal times for different fill heads on the gravity filling machine. Operators should double check fill times for each individual head and adjust accordingly to reach the desired volume.
6. Fill Hold/Fill Supply
On automatic liquid fillers with a supply tank, turning off the fill hold or supply hold can result in minor inconsistencies in fills as well. Fill hold and supply hold, in essence, ensure that fill cycles and resupply pumps do not run at the same time. If the tank is low, a resupply pump will add more product from the bulk supply. Doing so during the fill can affect the accuracy of the affect the fill. These two settings ensure, respectively, that if the tank is being resupplied, a fill cycle will not begin or if a fill cycle is in process, the resupply pump will not turn on. Operators can check to ensure the fill and supply hold are on at the touchscreen operator interface on the filler control panel.
Again, other causes for inconsistent fills exist, and different issues may exist for different fill principles. For those occasions when operators cannot resolve inconsistent fills, or any other filling machine issue, Liquid Packaging Solutions technical support is available during regular business hours and can be reached toll free at 1-888-393-3693.