https://www.avient.com/sites/default/files/2022-06/Maxxam FR Injection Molding Processing Guide.pdf
Vents should be placed at the intersection of each 90° bend in the runner
system off of the cold slug well and vented to atmosphere
Black Specks
Contamination
• Purge barrel with general purpose PP
• Verify correct nozzle is being used
• Pull screw for cleaning
Degraded/overheated
material
• Decrease melt temperature
• Decrease injection speed
• Use appropriately sized barrel
Brittleness
Degraded/overheated material
• Decrease melt temperature
• Decrease injection speed
• Use appropriately sized barrel
Gate location and/or size
• Relocate gate to nonstress area
• Increase gate size to allow higher flow rate and
lower molded-in stress
Burning
Process related
Mold design • Clean, widen and increase number of vents
• Increase gate size to reduce shear
Fibers/Minerals on
Surface or Uneven
Surface Appearance
Melt temperature too low
• Increase injection speed
Insufficient packing • Increase hold pressure and time
Flash
Injection pressure
too high
• Decrease injection pressure
• Increase clamp pressure
• Increase transfer position
Excess material volume
• Decrease pack pressure
• Decrease shot size
Melt and/or mold too hot
• Decrease screw speed
Loose clamp • Reset mold height
• Increase clamp tonnage
Troubleshooting Recommendations
Incomplete Fill
Melt and/or mold too cold
• Increase nozzle and barrel temperatures
Mold design
• Enlarge or widen vents and increase number
of vents
• Check that vents are unplugged
• Check that gates are unplugged
• Enlarge gates and/or runners
• Perform short shots to determine fill pattern
and verify proper vent location
• Increase wall thickness to move gas trap to
parting line
Shot size • Adjust transfer position to 98% full
Nozzle Drool Nozzle temperature too hot
• Decrease nozzle temperature
• Increase screw decompression
Shrink
Too much shrink • Increase cooling time
Too little shrink • Decrease cooling time
Sink Marks
Part geometry too thick • Reduce wall thickness
• Reduce rib thickness
Melt too hot • Decrease nozzle and barrel temperatures
Insufficient material
volume
• Increase packing pressure
Troubleshooting Recommendations (continued)
Sticking in Mold
Overfilled cavity
• Decrease injection rate and pressure
• Decrease hold pressure
• Decrease cooling time
Mold design • Increase draft angle
• Polish cores in direction of ejection
Part is too hot
• Increase cooling time
Warp
Process related
• Increase cooling time
• Increase pack pressure
• Increase pack time
Mold design • Inspect for non-uniform mold cooling
Part design • Inspect for non-uniform wall thickness
Temperature control unit
incorrect temperature
• Check settings
• Inspect thermocouple
Weld Lines
Melt front temperatures
are too low
• Increase pack and hold pressure
Mold design
• Increase gate size
• Perform short shots to determine fill pattern
and verify proper vent location
• Add vents and/or false ejector pin
• Move gate location
1.844.4AVIENT
www.avient.com
Copyright © 2022, Avient Corporation.
https://www.avient.com/sites/default/files/2022-06/Nymax BIO Bio-based Polyamide Solutions Processing Guide.pdf
Increase cooling time
Black specks
Contamination 1.
https://www.avient.com/sites/default/files/resources/HIGH_PERFORMANCE_CLEAR_THERMOPLASTICS_ELASTOMER.pdf
Styrene domain is stained black.
https://www.avient.com/resources/safety-data-sheets?page=2516
TE-0226071 BLACK
PA66 G25 H black
PG 173388.00 GN PEARL PE SL
https://www.avient.com/resources/safety-data-sheets?page=6745
PG 364433.00 PEARL GY PE
ZHEA BLACK TRIAL 11
ZHEA BLACK TRIAL 12
https://www.avient.com/resources/safety-data-sheets?page=6304
BLACK 7C ABS
BLACK 431C ABS
LAGOON BLUE AM PE
https://www.avient.com/resources/safety-data-sheets?page=3908
UV BLACK JADE 437
PE PINK
XAR19888 BLACK
https://www.avient.com/resources/safety-data-sheets?page=4767
GEON R5257A BLACK 2999
BLACK V2
PG 252689.00 FT PE SL
https://www.avient.com/resources/safety-data-sheets?page=2269
PG 99821.00 PEARL BU PE
JA6A/BLACK/LP/375
DX9/BLACK/7855E1
https://www.avient.com/resources/safety-data-sheets?page=3577
RACE BLACK
PE.
BLACK G2709