Tray Former Troubleshooting: Causes & Fixes

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Problems on this page:

Glue corners not holding Blanks not picked from the magazine Trays out of square Glue guns clogging or stringing Blanks warping Jams at the forming die Hot melt melter faults Slow size changeovers Glue on the tray walls or on the product side Trays sticking in the forming die

Glue corners not holding

Hits OEE: Quality

Symptoms: Tray corners open during packing or on the pallet.

Hot melt temperature wrong

Set the temperature the adhesive supplier specifies.

Too little glue or bead in the wrong place

Check the bead size and position.

Open time too long before compression

Check the timing between gluing and forming.

Coated or recycled board

Use an adhesive suited to the board.

Prevention: Corner bond checked on samples at start-up.

Blanks not picked from the magazine

Hits OEE: Availability

Symptoms: The machine misses blanks or picks two at once.

Suction cups worn

Replace the cups.

Vacuum low

Check the vacuum generator and the air supply.

Magazine pressure wrong

Adjust the magazine pusher.

Blanks stuck together

Fan the blanks and check storage.

Prevention: Suction cups checked weekly.

Trays out of square

Hits OEE: Quality

Symptoms: Formed trays are skewed and jam in the packer.

Forming plunger and die misaligned

Align the plunger to the die.

Blanks off-square from the supplier

Check the blank dimensions.

Scores not cut deep enough

Ask the supplier to check the scoring.

Glue holding the tray before it is square

Adjust the timing.

Prevention: Squareness checked on the first trays of each run.

Glue guns clogging or stringing

Hits OEE: Availability

Symptoms: Guns spit, string or stop dispensing.

Charred adhesive in the tank

Keep the tank lid closed and clean it on schedule.

Nozzle blocked

Clean or replace the nozzle.

Temperature too low

Check the temperature.

Filter blocked

Replace the melter filter.

Prevention: Melter cleaning on the planned schedule.

Blanks warping

Hits OEE: Availability

Symptoms: Curved blanks cause misfeeds and jams.

Board stored in damp or dry conditions

Store board in the conditions the supplier states.

Pallets left open too long

Keep pallets wrapped until used.

Board too thin for the size

Check the board specification.

Machine area humidity swings

Keep the packing area conditions stable.

Prevention: Blank flatness checked at pallet change.

Jams at the forming die

Hits OEE: Availability

Symptoms: Blanks crash or stop in the die.

Die set for a different size

Check the change parts.

Blank feed timing wrong

Reset the timing.

Worn die guides

Replace worn guides.

Bent blanks

Remove damaged blanks.

Prevention: Change parts checked at every size change.

Hot melt melter faults

Hits OEE: Availability

Symptoms: The melter alarms on temperature or level.

Heater fault

Check the heaters.

Level sensor dirty

Clean the sensor.

Auto feed of pellets blocked

Check the feeder.

Hose heater failed

Replace the hose.

Prevention: Melter alarms logged.

Slow size changeovers

Hits OEE: Availability

Symptoms: Changing tray size takes long and the first trays are bad.

Settings not recorded

Record settings for each size.

Change parts not marked

Mark and store change parts by size.

Tools missing at the machine

Keep the tools at the machine.

No first-off check

Check the first tray before releasing the run.

Prevention: Changeover time recorded per change.

Glue on the tray walls or on the product side

Hits OEE: Quality

Symptoms: Hot melt shows outside the glue flaps, strings across the tray, or ends up where product will touch it.

Gun nozzle aimed outside the flap area

Realign the nozzle so the bead lands in the middle of the glue flap for every size.

Bead pattern timing not set for the line speed

Reset the gun timing whenever the speed or tray size changes.

Nozzle dripping between cycles

Check the gun module and replace a worn needle or seat.

Adhesive too hot and too runny

Run at the temperature the adhesive supplier gives, not higher.

Prevention: Glue pattern checked on the first trays after every size change.

Trays sticking in the forming die

Hits OEE: Availability

Symptoms: Formed trays do not release from the die and the next blank crashes into them.

Adhesive build-up on the die

Clean the die and the plunger on a fixed schedule.

Die walls worn or rough

Polish or replace the worn die sections.

Tray ejection timing wrong

Check the ejection or plunger return timing.

Board too thick for the die setting

Check the board caliper against the die setting.

Prevention: Die cleaning added to the weekly round.

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

Related equipment guides: case erector · case packer · case sealer · shrink wrapper

Stop the same fault coming back

Recurring tray former 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