Pouch Filling Machine Troubleshooting: Causes & Fixes

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Problems on this page:

Pouches not opening at the filling station Leaking or weak top seals Fill weight varying Zipper not closed or damaged Gripper drops pouches Nitrogen flush or vacuum not reaching target Long changeovers between pouch sizes Date code missing or unreadable

Pouches not opening at the filling station

Hits OEE: Availability

Symptoms: Premade pouches are not opened fully, so product misses the pouch or the machine stops.

Opening suction cups worn or dirty

Clean or replace the suction cups and check the vacuum at each station.

Air jet for opening blocked or set wrong

Clean the opening air nozzle and check its timing.

Pouch stock out of specification

Check the pouch dimensions and the zipper or top area against the specification.

Pouches stuck together in the magazine

Fan the pouches before loading and check the stack for static or damp.

Prevention: Missed openings counted per shift and per gripper station.

Leaking or weak top seals

Hits OEE: Quality

Symptoms: Seal checks find leaks, wrinkles or seals that peel too easily.

Seal jaw temperature, pressure or dwell wrong

Compare the seal settings with the approved recipe for that pouch film.

Product in the seal area

Check the filling nozzle position and add a settling step or stretch so the seal area stays clean.

Seal jaws dirty or worn

Clean the jaws and check their faces and coverings for damage.

Pouch not held flat during sealing

Check the gripper spread so the pouch top is flat when the jaws close.

Prevention: Seal integrity tested on samples each hour.

Fill weight varying

Hits OEE: Quality

Symptoms: Checkweigher results show underfills and overfills from the same machine.

Filler or weigher not calibrated

Calibrate the filler or the weigher feeding it.

Product flow from the hopper uneven

Check the hopper level control and the product feed.

Timing between filler and pouch station drifting

Check the filling signal timing against the turret position.

Product spilling outside the pouch

Check the funnel alignment with the pouch opening.

Prevention: Checkweigher results reviewed per hour and per filling head.

Zipper not closed or damaged

Hits OEE: Quality

Symptoms: Reclosable pouches leave the machine with open or crushed zippers.

Zipper closing rollers set wrong

Adjust the zipper closing station as the maker specifies.

Seal jaws crushing the zipper

Check the jaw position relative to the zipper.

Pouch stock with misplaced zippers

Check the zipper position on incoming pouches.

Product caught in the zipper

Check that the fill does not reach the zipper area.

Prevention: Zipper function checked on samples each hour.

Gripper drops pouches

Hits OEE: Availability

Symptoms: Pouches fall from the grippers during indexing.

Gripper spring force weak

Check and replace gripper springs.

Gripper pads worn smooth

Replace worn gripper pads.

Gripper width wrong for the pouch size

Set the gripper width for the pouch in use.

Indexing too fast for a heavy fill

Check the speed setting for heavy products.

Prevention: Dropped pouches counted per gripper station.

Nitrogen flush or vacuum not reaching target

Hits OEE: Quality

Symptoms: Residual oxygen in the pouch is above the limit.

Nitrogen supply pressure low

Check the nitrogen supply and regulator.

Flush nozzle position wrong

Check the nozzle position over the pouch opening.

Seal closes too long after flushing

Check the timing between flush and seal.

Leaking seals letting air back in

Work through the seal causes.

Prevention: Residual oxygen measured on samples each hour.

Long changeovers between pouch sizes

Hits OEE: Performance

Symptoms: Changing pouch size takes long, and the first pouches are wasted.

Change parts not ready

Stage the gripper and funnel parts before the run ends.

Settings not stored per size

Store the gripper width, seal settings and fill settings per size.

Adjustments by trial and error

Mark positions on scales so settings can be repeated.

No written sequence

Write the changeover sequence and train the operators on it.

Prevention: Changeover time recorded per size change.

Date code missing or unreadable

Hits OEE: Quality

Symptoms: The code on the pouch is missing, smudged or in the wrong place.

Coder not triggered by the pouch

Check the trigger sensor and its timing.

Print head dirty

Clean the print head as the coder maker specifies.

Pouch surface not suited to the ink

Check the ink for the pouch film.

Code position moved after a changeover

Check the coder position for each pouch size.

Prevention: Codes checked on samples each hour and at every changeover.

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

Related equipment guides: form-fill-seal machine · multihead weigher · checkweigher · inkjet coder · vacuum packaging machine

Stop the same fault coming back

Recurring pouch filling machine 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