Problems on this page:
Fill volume or weight off target
Hits OEE: Quality
Symptoms: Filled bags are under or over the declared quantity.
Flow meter or weigh cell not calibrated
Calibrate the flow meter or the weigh cell against a reference.
Product temperature or foaming changing the reading
Check the product temperature and foam at the filler.
Valve closing late or early
Check the filling valve timing and its actuator.
Bag not fully evacuated before filling
Check the vacuum step before filling.
Prevention: Fill checked on a sample of bags each hour.
Cap or fitment not sealing
Hits OEE: Quality
Symptoms: Filled bags leak at the cap or fitment.
Capping head not pressing the cap fully
Check the capping pressure and head alignment.
Cap or fitment out of specification
Check incoming bags and caps against the specification.
Product on the fitment before capping
Check the drip after the filling valve closes.
Cap feed delivering damaged caps
Check the cap feed track for damage.
Prevention: Fitment leaks checked on samples each hour.
Bags not loading on the filling head
Hits OEE: Availability
Symptoms: The bag gland does not seat on the filler, and the operator has to retry.
Gland clamp worn
Check the gland clamp and its jaws for wear, and replace them as a set.
Bag fitment size not matching the head
Check that the change parts fitted match the fitment type of the bags in use.
Web-fed bags not separating
Check the perforation between bags and the web feed tension.
Sensor not detecting the fitment
Clean the fitment sensor and set its detection point for the fitment type.
Prevention: Loading retries recorded per shift.
Microbial contamination in aseptic fills
Hits OEE: Quality
Symptoms: Lab results find spoilage in aseptically filled bags.
Sterilisation step not reaching temperature or time
Check the steam or chemical sterilant cycle data for each fill.
Sterile zone barrier broken
Check the barrier, filters and overpressure of the filling chamber.
Bags not sterile from the supplier
Check the supplier certificates for the lot.
Cleaning and sterilisation of the product line incomplete
Check the line sterilisation records.
Prevention: Sterilisation records reviewed for every production run.
Bags bursting or creasing in the box
Hits OEE: Quality
Symptoms: Bags crease, burst or leak after they are placed in the box.
Bag size wrong for the box
Check the bag and box combination against the specification.
Bag dropped into the box from too high
Lower the transfer height into the box.
Air left in the bag
Check that each bag is fully evacuated before filling, so no air pocket stresses the film in the box.
Film scuffed on guides or edges
Check the guides and box flaps for sharp edges.
Prevention: Bags inspected inside the box on samples each shift.
Filling time too long
Hits OEE: Performance
Symptoms: Each bag takes longer to fill than the standard, and output falls.
Product supply pressure low
Check the supply pump and the level in the supply tank.
Product filter blocked
Change or clean the filter ahead of the filler.
Filling valve not opening fully
Check the valve stroke and its actuator air.
Foaming slowing the fill
Check the product temperature and the fill speed profile.
Prevention: Fill time per bag trended.
Vacuum step faults
Hits OEE: Availability
Symptoms: The filler stops because the bag does not reach vacuum before filling.
Vacuum pump worn
Check the pump output and its oil or water supply.
Leaks in the vacuum line
Find leaks at fittings and hoses.
Seal at the filling gland worn
Replace the gland seal.
Vacuum sensor faulty
Check the sensor against a gauge.
Prevention: Vacuum level logged per bag.
Cleaning problems
Hits OEE: Availability
Symptoms: The cleaning cycle fails its checks, or residue is found after cleaning.
Cleaning solution temperature low
Check the heating of the cleaning solution during the cycle.
Detergent concentration low
Check the dosing and measure the concentration during the cycle.
Flow through the filling valves too low
Check the cleaning pump and that every valve opens during cleaning.
Dead legs in the product line
Find and remove dead legs where product sits.
Prevention: Cleaning records reviewed after every clean.
Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.
Related equipment guides: filling machine · capping machine · CIP system · case erector · vacuum pump
Stop the same fault coming back
Recurring bag-in-box filler stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.
Book a Fabrico demo
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Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary
Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover