Tablet Counter Troubleshooting: Causes & Fixes

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Problems on this page:

Wrong count in the bottle Dust building up on the sensors Tablets chipping or breaking Bottles not stopping under the nozzle Tablets bridging in the hopper Reject system not removing bad bottles Counting slower than expected Tablets left in the machine at line clearance Machine stopping on bottle not present

Wrong count in the bottle

Hits OEE: Quality

Symptoms: Checkweighing or audits find bottles with one tablet too many or too few.

Dust on the counting sensors

Clean the sensors and channels as the procedure sets, more often for dusty products.

Vibration too high, so tablets pass in pairs

Lower the vibration so tablets travel in single file through the sensors.

Channel setup not matched to the tablet size

Fit the channel plates for this tablet and check them at each changeover.

Broken tablets counted as whole ones

Check tablet hardness and the drop heights that break tablets.

Prevention: Count accuracy challenged with a known number of tablets at start-up.

Dust building up on the sensors

Hits OEE: Availability

Symptoms: Sensor alarms appear and the machine stops for cleaning more often than planned.

Dusty tablets from compression or coating

Dedust tablets before counting and raise dusty batches with compression.

Dust extraction not running or weak

Check the extraction at the channels and its filter.

Cleaning interval too long for the product

Set the cleaning interval per product.

Static holding dust on surfaces

Check earthing and the ionisation if fitted.

Prevention: Sensor cleaning logged with the time between alarms.

Tablets chipping or breaking

Hits OEE: Quality

Symptoms: Bottles contain chipped tablets or fragments.

Vibration amplitude too high

Reduce the vibration to the lowest setting that keeps the rate.

Drop height into the bottle too large

Adjust the funnel and nozzle so tablets fall a short distance.

Tablets softer than usual

Check the batch hardness against its specification.

Gates closing on tablets

Check the gate timing.

Prevention: Bottles opened and inspected on a sample basis.

Bottles not stopping under the nozzle

Hits OEE: Availability

Symptoms: Bottles arrive off centre or too late, and tablets spill.

Change parts not set for the bottle size

Fit and set the guides and stops for the bottle in use.

Conveyor speed not matched to the counter

Check the conveyor and indexing settings.

Bottle sensor misaligned

Adjust the sensor.

Bottle stop gate worn

Replace the worn stop.

Prevention: Changeover checklist covers guides, stops and sensors.

Tablets bridging in the hopper

Hits OEE: Performance

Symptoms: Feed into the channels stops or slows, and counting rate drops.

Hopper level too high

Keep the hopper at the level the maker recommends.

Tablet shape that interlocks or sticks

Use the flow aids the maker offers for this shape.

Humid room making tablets sticky

Check the room humidity.

Hopper gate opening too small

Set the gate for the tablet size.

Prevention: Counting rate trended per product.

Reject system not removing bad bottles

Hits OEE: Quality

Symptoms: Bottles flagged as wrong count are not rejected.

Reject gate air pressure low

Check the air supply to the reject device.

Reject timing wrong for the line speed

Set the timing and test with marked bottles.

Reject confirmation sensor faulty

Check the sensor that confirms each reject.

Reject bin full

Empty the bin and fit a full bin alarm.

Prevention: Reject system challenged with test bottles at start-up.

Counting slower than expected

Hits OEE: Performance

Symptoms: The line runs below its rated bottles per minute.

Vibration set low for a careful product

Find the highest vibration that still gives clean counts.

Channels partly blocked

Clean the channels.

Waiting for bottles at the infeed

Check the unscrambler and conveyor ahead of the counter.

Downstream capper backing up

Check the capper and its accumulation.

Prevention: Rate and stops recorded per product.

Tablets left in the machine at line clearance

Hits OEE: Quality

Symptoms: Tablets from the last batch are found in channels or corners after clearance.

Crevices that trap tablets

List the places tablets lodge and check each one in the clearance.

Clearance procedure missing parts of the machine

Update the procedure with photos of each area.

Rushed clearance

Use a second person to verify.

Poor lighting

Use a torch for the clearance check.

Prevention: Line clearance verified and signed by a second person.

Machine stopping on bottle not present

Hits OEE: Availability

Symptoms: The machine stops with a no bottle alarm while bottles are there.

Sensor misaligned or dirty

Clean and realign the sensor.

Gaps in the bottle feed

Check the unscrambler output and conveyor.

Sensor sensitivity wrong for the bottle colour

Set the sensor for clear or coloured bottles.

Reflections from the guides

Shield the sensor from reflections.

Prevention: Sensor settings recorded per bottle type.

Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.

Related equipment guides: capsule filler · tablet press · capping machine · labelling machine · checkweigher · capsule polisher

Stop the same fault coming back

Recurring tablet counter 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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Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover