Quick Fix Checks for Inconsistent Fills
Inconsistent fills can stem from a variety of different sources, but whatever the source, it is a frustrating issue to experience during a production day. More often than not, correcting inconsistent fills will be a quick and easy process. Below are the most common causes of sudden inconsistent fills.
If equipment has been recently moved, a packager should check to ensure that the filler is sitting level on the production floor. Even if the machine is sitting right where it always has, a machine may have been bumped or moved during maintenance. A filling machine that is not sitting level can cause inconsistent fills regardless of the principle being used, from overflow to gravity to pump or piston.
After verifying that the machine is sitting level, there are several other quick checks that may lead to the cause of the inconsistent fills. Packagers should check air lines for leaks as well, including hose barbs or locking collars or other components that could cause air to leak if not tightened appropriately. Air leaks can lead to low air pressure, which again can cause fills to sudden become inconsistent. Ensuring all clamps, barbs and other connections are tight can quickly correct inconsistent fills.
Automatic filling machines almost always include a recipe screen on a touchscreen interface that allow packagers to save and recall settings for specific bottle and product combinations. These include indexing times, filling times and other delay and duration times that make up each fill cycle. If inconsistent fills are encountered at the beginning of a run after a filler has been running efficiently, packagers will want to ensure that the correct recipe has been entered for the product and bottle being run. Using the wrong recipe means using the wrong times, which will almost always lead to inconsistent fills.
For some machines, the recipe screen will also allow the manual adjustment of fill times for all fill heads or each fill head individually. Though rare, fill times may need to be adjusted if a product changes viscosity as temperature changes. In these cases, the issue could stem from changes in the environment on the production floor or storage of the product. A product that gets more viscous as it gets colder, for example, fill times may need to be slightly adjusted in winter and summer months, if the production floor is affected by the season.
Many filling machines will also use a supply tank to ensure product is always available to the filling machine. This supply tank will be resupplied with product as necessary to keep head pressure stable, which helps ensure consistent fills. Head pressure can change when the tank is low or being resupplied. On the same operator interface, a packager can check to ensure the Fill Hold and Supply Hold are both turned on. These two controls will pause the resupply or the fill until the end of a fill cycle to ensure head pressure stays steady. Having these controls set to the off position can also lead to inconsistent fills.
Finally, there are a couple of specific quick checks for those using the unique overflow filling machine. Overflow fillers use spacers on each fill head to achieve a fill that reaches the same level in each bottle, each cycle. For this reason, the spacers need to be the same on each fill head. When changing over from one bottle to another, the spacers may also need to be changed. For those experiencing inconsistent fills on an overflow filler, spacers should be checked to ensure all heads are the same.
Overflow fillers also dive into and create a seal over the bottle opening during the fill. Inconsistent fills on an overflow filler can be caused by worn bottle seals that allow air or product to escape during the fill. Even slight leaks can cause inconsistency, so packagers with an overflow filler should visually inspect their bottle seals and replace them when necessary to keep fills consistent.
While not an exhaustive list of possible solutions for inconsistent fills, a majority of such issues will be resolved by checking that the machine is level, looking for air leaks and inspecting the other common issues mentioned above. If these do not to resolve the issue, LPS technicians are available to consult and assist in finding the cause and the best solution for inconsistent fills.