Capsule Polisher Troubleshooting: Causes & Fixes

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Problems on this page:

Capsules dented or split in the polisher Powder dust remaining on capsules Empty or light capsules not rejected Static making capsules stick Polisher motor or drive stopping Cleaning and changeover problems Metal contamination risk from the polisher Capsules leaving the polisher out of order

Capsules dented or split in the polisher

Hits OEE: Quality

Symptoms: Capsules come out of the polisher dented, split or with damaged bands.

Brush speed or pressure too high for the capsule size

Set the brush speed and gap for the capsule size in use.

Capsules too brittle from low humidity

Check the room humidity against the capsule supplier range.

Feed rate too high, so capsules jam at the inlet

Reduce the feed rate from the capsule filler.

Worn or damaged brush bristles

Replace the brush when bristles are worn or bent.

Prevention: Capsules inspected on samples after polishing.

Powder dust remaining on capsules

Hits OEE: Quality

Symptoms: Polished capsules still carry powder dust on the shell.

Dust extraction airflow low

Check the extraction fan, hose and filter.

Brush clogged with powder

Clean the brush at the interval set for the product.

Capsules passing through too fast

Check the polisher speed and incline.

Filler leaving more powder on shells

Check the capsule filler dosing and closing station.

Prevention: Shell cleanliness checked on samples each hour.

Empty or light capsules not rejected

Hits OEE: Quality

Symptoms: Light or empty capsules pass the polisher reject station.

Reject air jet or sorter set wrong

Check the reject setting with test capsules of known weight.

Air pressure to the reject station low

Check the air supply.

Rejector nozzle blocked with powder

Clean the nozzle.

Capsules overlapping at the reject point

Reduce the feed rate so capsules pass one at a time.

Prevention: Reject station challenged with test capsules at each start.

Static making capsules stick

Hits OEE: Availability

Symptoms: Capsules cling to the polisher and to each other, slowing the flow.

Room humidity too low

Check humidity against the capsule supplier range.

Anti-static device not working

Check the ioniser if fitted.

Polisher parts not earthed

Check the earth connections.

Plastic chutes charging the capsules

Use conductive chute materials where possible.

Prevention: Flow problems recorded with the room humidity.

Polisher motor or drive stopping

Hits OEE: Availability

Symptoms: The brush stops turning or the motor trips.

Capsule jam at the inlet

Clear the jam with the polisher switched off.

Drive belt worn

Replace the drive belt and set its tension.

Motor overloaded by a clogged brush

Clean the brush and compare the motor current with its rating.

Speed controller fault

Check the speed controller and compare its settings with the record.

Prevention: Drive faults logged.

Cleaning and changeover problems

Hits OEE: Availability

Symptoms: Product changeovers take long because the polisher is hard to clean.

Brush not removed for cleaning

Remove the brush and housing as the cleaning procedure describes.

Powder trapped in the housing joints

Clean the joints and seals and check them for wear.

No spare brush to swap in

Keep a clean spare brush so cleaning can happen off the line.

Cleaning not documented

Use a cleaning record signed by the operator and checked by quality.

Prevention: Changeover cleaning time recorded.

Metal contamination risk from the polisher

Hits OEE: Quality

Symptoms: A metal detector after the polisher rejects capsules.

Worn metal parts in the polisher shedding particles

Inspect the polisher for wear at moving metal parts.

Screws or fittings loose

Check all fixings on the polisher.

Metal detector set too sensitive

Check the detector settings with test pieces.

Product effect on the detector

Check the product setting on the detector.

Prevention: Metal detector rejects reviewed per batch.

Capsules leaving the polisher out of order

Hits OEE: Quality

Symptoms: Capsules from the end of one batch mix into the next.

Capsules left inside after the batch

Run the polisher empty and check it is clear at batch end.

Line clearance missed

Include the polisher in the line clearance checklist.

Hidden pockets in the housing

Check the housing for pockets where capsules stay.

Discharge chute not emptied

Check the chute at every batch end.

Prevention: Line clearance recorded for the polisher at every batch end.

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 · metal detector · tablet counter · dust collector · blister pack machine

Stop the same fault coming back

Recurring capsule polisher 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.

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