Folder Gluer Troubleshooting: Causes & Fixes

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Problems on this page:

Glue joints opening Panels misaligned (fishtail)Glue skips Glue squeezing out Feeder misfeeds or double blanks Creases cracking Blanks skewing on the belts Delivery counting or stacking errors Jams in the folding section

Glue joints opening

Hits OEE: Quality

Symptoms: Cartons pop open at the glue flap in the delivery or at the customer.

Too little glue

Check the glue pattern and the amount applied.

Compression too short or too light

Check the compression section pressure and length for the board.

Glue not suited to the board coating

Check the glue type with the supplier for coated or varnished board.

Glue too cold or too thick

Check the glue temperature and viscosity.

Prevention: Glue joint checked on samples from each pallet.

Panels misaligned (fishtail)

Hits OEE: Quality

Symptoms: The folded panels do not line up, so the carton is skewed.

Carrier belt speeds not matched

Match the upper and lower belt speeds.

Folding belts set wrong

Check the folding belt positions for the carton.

Board curl

Check board storage and use the pre-breaker.

Blanks entering skewed

Check the feeder alignment.

Prevention: Fold alignment checked at start-up.

Glue skips

Hits OEE: Quality

Symptoms: Some cartons have no glue or a broken glue line.

Glue nozzle partly blocked

Clean the nozzle and check its filter.

Trigger sensor missing blanks

Clean and set the sensor.

Glue pressure low

Check the glue pump pressure.

Glue detection not switched on

Use glue detection and test it with a blank without glue.

Prevention: Glue detection tested at start-up.

Glue squeezing out

Hits OEE: Quality

Symptoms: Glue oozes from the joint and sticks cartons together.

Too much glue

Reduce the glue amount until the joint holds without glue showing at the edge.

Glue line too close to the edge

Move the glue line in from the edge.

Compression too high

Reduce the compression pressure so glue is not forced out of the joint.

Glue too thin

Check the glue viscosity and temperature against the supplier data.

Prevention: Glue amount set per carton.

Feeder misfeeds or double blanks

Hits OEE: Availability

Symptoms: The feeder misses blanks or feeds two at once.

Feeder gate set wrong for the board thickness

Set the gate for the board caliper.

Blanks warped

Flatten warped stacks and check storage.

Feeder belts worn

Replace worn feeder belts.

Stack too heavy on the feeder

Keep the stack height within range.

Prevention: Feeder settings recorded per job.

Creases cracking

Hits OEE: Quality

Symptoms: The board cracks along the folds.

Board too dry

Check board moisture and storage.

Creases not pre-broken

Use the pre-breaker.

Crease depth from die cutting wrong

Check the creasing with the die cutting team.

Folding too fast

Reduce speed for stiff board.

Prevention: Fold quality checked on samples.

Blanks skewing on the belts

Hits OEE: Quality

Symptoms: Blanks twist as they travel, so folds are crooked.

Carrier belt tension uneven

Set the carrier belt tension evenly on both sides.

Side guides set for another job

Set the side guides for the blank width at each job change.

Worn carrier belts

Replace belts whose grip surface is worn.

Board dust on the belts

Clean the belts so they grip the blank evenly.

Prevention: Belt condition checked weekly.

Delivery counting or stacking errors

Hits OEE: Availability

Symptoms: Wrong counts per bundle or stacks falling over at the delivery.

Counter sensor dirty

Clean the counting sensor and check its alignment.

Kicker timing wrong for the job

Set the kicker timing for the bundle count and speed.

Shingle in the delivery uneven

Adjust the delivery speed so cartons overlap evenly.

Cartons springing open in the delivery

Check the compression belt length and pressure.

Prevention: Bundle counts checked on samples.

Jams in the folding section

Hits OEE: Availability

Symptoms: Blanks jam in the folding section and the machine stops.

Folding hooks or rods set wrong

Check the folding tools against the set-up sheet for the carton.

Blank dimensions out of tolerance

Measure blanks from the die cutter and raise variation with that team.

Speed too high for the carton style

Reduce speed for complex cartons until the folds run cleanly.

Board scraps caught on the belts

Remove scraps and check the stripping at the die cutter.

Prevention: Jams recorded by position.

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

Related equipment guides: die cutter · offset press · case packer · flexo press · cartoner · hot foil stamping machine

Stop the same fault coming back

Recurring folder gluer 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