While it would be impossible to cover every troubleshooting scenario for every packaging machine in production, there are some recurring issues that have cropped up over the years. Some of the most common problems don’t always have an obvious solution, although most of the time a simple fix will have your computer running consistently and reliably in no time. Below are some of those common problems, along with typical solutions.
1. Inconsistent filling
Of course, different filling machines use different filling principles and different types of nozzles. Therefore, inconsistent fill can come from different sources depending on the type of liquid filler being used on a packaging line. However, in general, the source is usually an incorrect configuration of the filling machine or wearing parts that need to be replaced.
During installation of the bottle filler, the nozzles must be positioned correctly over the bottles. Some nozzles, like those found on an overflow filler, will dip into a bottle and create a seal. The compression on these nozzles must also be set correctly to achieve even, level fills. Operators experiencing inconsistent filling should first check the physical setup of the equipment, making sure the nozzles are aligned with the cylinders and diving correctly. A powered conveyor system will also typically move bottles in and out of the filling area, with the help of an indexing system such as in-out pins, a star wheel, or some other type of system. The operator must check the guide rails to ensure bottles are consistently aligned in the correct position, as well as the indexing system to ensure bottles are stabilized while in the fill area.
Automatic filling machines will normally be controlled by a PLC, accessed via a touch screen interface found on the control panel of the machinery. The operator interface will allow the user to set fill times as well as delay and duration times for components such as the plunge head, pump, indexing and more. Typically these machines will come with settings for individual bottles pre-set on a recipe screen. Inconsistent fills can arise from having incorrect fill times, delay times, or duration times, or by entering the wrong recipe for the product and bottle being processed. The operator should also double check to make sure all settings are correct. As a side note, it’s always a good idea to keep a hard copy of all times and settings in case of damage to the PLC due to a harsh environment, power outage, or other unforeseen circumstances.
Once these checks have been completed, if inconsistent fills continue, any worn parts found on the packaging machine should be inspected and replaced if necessary. Many nozzles will include o-rings or seals that will eventually require replacement. These o-rings, seals, and similar components can allow air to enter the product path at various points, leading to inconsistent fills. In fact, operators must also inspect and tighten the hose clamps that connect the tubing to the machine along the product path, since something as simple as a small amount of air entering the tubing path can cause inconsistencies. Running these simple checks will lead the operator to solutions for problem fills most of the time.
2. Inconsistent limits
Once a packaging line fills steadily, the last thing an operator wants to deal with is inconsistent capping, which can lead to cross-threads, loose caps, or impossible-to-open tight caps. As with filling machines, capping equipment will differ depending on the type of cap and seal used. However, a simple inspection of the setup and wear parts will usually once again lead to a solution.
The capping apparatus, whether it be spindle wheels, a chuck head, snap strap, or other device, must be positioned correctly to reliably and consistently seal containers. The operator must first check the capping apparatus to ensure that the caps are in contact in the correct position to create this reliable and consistent seal. Adjustment will usually involve simple changes to the height and width of the fixture, and may involve some trial and error. If the capping apparatus appears to be positioned correctly, attention should be paid to the components used to stabilize the bottle and cap. Grip straps, guide rails, lid tabs, and lid stabilizer bars will be used to ensure a proper seal. If bottles or caps are not stabilized, movement can play havoc with the capping process. Inspect these stabilizing elements to ensure bottles and caps are secure throughout the sealing process.
The wear parts of the capping machine are generally contact parts. Spindle wheels turn down screw caps on, snap straps apply pressure to snap caps on. Grip straps make contact with the bottle to stabilize it during the capping process. As these parts wear out, they become less effective. Operators can inspect the wear parts on their specific bottle capper and make replacements as needed. Again, following these simple steps will resolve the inconsistent throttling most of the time.
3. Overturned Bottles and Spills
The key to solving bottle tip-over and spill problems is locating the source. If the releases or spills occur in one location, the operator may need to go back to the facility inspections described above. An incorrectly positioned indexing system on a filling machine, for example, can cause bottles to tip over. Incorrect fill times can cause spills. Gripper straps that squeeze a bottle tightly can push product out of that bottle before the cap is properly tightened at the capping and sealing station. If leaks or bottle spills can be identified at a single machine or location, inspect the machine and make any necessary adjustments.
If seemingly random spills or spills occur along the packaging line, the problem may be the transfer system, typically an electric conveyor system. The operator must inspect the conveyor belt, as well as any transfer locations, for damage. A crack or missing piece of the belt can cause bottles to become unstable as they move along the conveyor. Damage to a transfer plate between conveyors can cause bottles to jump or tip over as well. Finally, the operator can verify that conveyor speeds are correct and consistent throughout the packaging line. If one or more conveyors have inadvertently slowed down or sped up, shifting from one speed to another can cause tip-overs, splashes and spills.
4. Machine components and PLC configuration
Occasionally, the entire packaging process will work fine, but a single component of a machine will fail. For example, drip trays and head dips in filling machines are common culprits. Normally, one of two configurations in the PLC will solve these problems. The operator interface for the PLC will almost always include a manual toggle screen, which is used to control certain components of the packaging machinery during machine setup or while performing maintenance. The drip tray can be retracted under the manual shift screen out of the way during setup or maintenance. However, if the setting is not returned to Auto before starting production, the drip tray will remain retracted. The first settings to check when a single component is not working properly are found on the Operator Interface Manual Toggle screen, set the component to Auto if it is not already in this position.
The Settings screen in the operator interface also includes settings for certain equipment components. For example, vision systems on packaging machinery can usually be set to read normally or inverted (depending on the type of bottle being used, clear or non-clear, for example). If the vision systems or other components of a packaging system are not working properly, the operator should visit the Settings screen to ensure that the component is enabled to work properly with the packaging and product.
While these simple solutions will solve most problems, there are always rare occasions when a solution evades discovery. Since packaging equipment is almost always built for the specific project it is used for, the operator should always count on the manufacturer for support. So if all else fails, pick up the phone and talk to a packaging specialist to get production back to the smooth, reliable, and consistent process you want.