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Technical Bulletin
Problem Possible Cause(s) Possible Solution(s)
Baggy Edges Excessive bow Adjust the bowed roll
Cloudy Bars Hot melt Decrease the barrel temperatureErratic cooling Check the air knife blower speed and adjust as
necessary
Core Collapse Warm film Decrease the temperature on the secondary chill roll
Tightly wound film Decrease winder tensionWeb shrinkage Decrease the temperature on the secondary chill roll
Die Lines Streaks Dirty die Clean die and/or die lips with copper pad or brass shimDamaged die lips Change die lips
Repair surfaceInadequate purging Check current purging time and increase as necessary
Edge Tearing Extrusion temperature Increase the extrusion temperature
Die gap Decrease the die gapScreen pack Increase restriction
Air gap Increase the air gapExtruder output/take up Decrease the output and/or take up speed
Excessive Neck-in Extrusion temperature Decrease the extrusion temperature
Resin density Use a resin with a lower densityResin melt index Use a resin with a lower melt index
Air gap Decrease the air gap
Extruder output/take up Increase the output rate and/or take up speedDie gap Increase the die gap
Film Blocking Additives Increase additive formulation, namely the ash levelExtrusion temperature Decrease extrusion temperature
Chill roll temperature Increase chill temperatureExtruder output/take up Decrease the output and/or the take up speed
Winder tension Decrease the winder tensionResin melt index Use a resin with a lower melt indexTreatment level Decrease the level of treatment
Die gap Decrease the die gapAir gap Decrease the air gap
Resin density Use a resin with a higher density
Film Puckering Chill roll temperature Increase the chill roll temperature
Extruder output/take up Decrease the output and/or take up speedResin density Use a resin with a lower density
HDPE Cast Film Troubleshooting
BP Solvay Polyethylene North America
3333 Richmond Avenue, Houston, Texas 77098-3099 Mailing: P.O. Box 27326, Houston, Texas 77227-7328Telephone: 1.800.231.6313 Fax: 713.522.2435 Technical Service: 1.800.338.0489 Customer Order Service: 1.800.527.5419www.bpsolvaype.com/na
TO THE BEST OF OUR KNOWLEDGE THE INFORMATION CONTAINED HEREIN IS ACCURATE. HOWEVER, NEITHER BP SOLVAY POLYETHYLENE NORTH AMERICA, NOR ANY OFITS AFFILIATES ASSUMES ANY LIABILITY WHATSOEVER FOR THE ACCURACY OR COMPLETENESS OF THE INFORMATION CONTAINED HEREIN. FINAL DETERMINATION OFTHE SUITABILITY OF ANY INFORMATION OR MATERIAL FOR THE USE CONTEMPLATED, THE MANNER OF USE, AND WHETHER THERE IS ANY INFRINGEMENT OF PATENTS ISTHE SOLE RESPONSIBILITY OF THE USER.
COPYRIGHT 2002, BP SOLVAY POLYETHYLENE NORTH AMERICA. ALL RIGHTS RESERVED. ISSUE DATE 7/2002.
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BP Solvay Polyethylene North America
3333 Richmond Avenue, Houston, Texas 77098-3099 Mailing: P.O. Box 27326, Houston, Texas 77227-7328Telephone: 1.800.231.6313 Fax: 713.522.2435 Technical Service: 1.800.338.0489 Customer Order Service: 1.800.527.5419www.bpsolvaype.com/na
TO THE BEST OF OUR KNOWLEDGE THE INFORMATION CONTAINED HEREIN IS ACCURATE. HOWEVER, NEITHER BP SOLVAY POLYETHYLENE NORTH AMERICA, NOR ANYOF ITS AFFILIATES ASSUMES ANY LIABILITY WHATSOEVER FOR THE ACCURACY OR COMPLETENESS OF THE INFORMATION CONTAINED HEREIN. FINAL DETERMINATION
OF THE SUITABILITY OF ANY INFORMATION OR MATERIAL FOR THE USE CONTEMPLATED, THE MANNER OF USE, AND WHETHER THERE IS ANY INFRINGEMENT OFPATENTS IS THE SOLE RESPONSIBILITY OF THE USER.
COPYRIGHT 2002, BP SOLVAY POLYETHYLENE NORTH AMERICA. ALL RIGHTS RESERVED. ISSUE DATE 7/2002.
Film Sticking Erratic cooling Check the chill roll temperatures and adjust
on Chill Roll as necessaryCheck the passages
Film Too Narrow Narrow die slot Adjust the deckles
from Chill Roll High neck-in Adjust the edge pinners air flow and relocate pinnersInsufficient roll tension Increase the tension as necessary
Floppy Web Insufficient roll tension Increase the tension as necessaryGauge Variation Surging of the extruder Check drive speed of the extruder
Check temperature controllersExamine feed section housing
See if the regrind feed is force feeding theextruder (blenders)Check for wearing of the screw and repair /
replace as necessaryExamine the filters for possible clogging and clean /
replace as necessary
Erratic melt quality Check and adjust temperature profiles as necessaryEnsure proper screw design
Check for wearing of the screw and repair /replace as necessaryModify screw design with static mixers to achieve
homogeneity
Die gap Decrease the die gapChill roll temperature Decrease the chill roll temperature
Air gap Decrease the air gap
Screen pack Increase restriction
Winder tension Increase tension of the winder
Gels Erratic melting and mixing Check temperature and adjust accordingly
Check for wearing of the screw and repair /replace as necessary
Check for wearing of the barrelCheck for resin contamination and purge if necessary
Screen pack Increase restriction
Hard Roll Excessive winder tension Decrease the tension
Excessive lay on pressure Decrease pressure
Hazy Roll Plate out on chill roll Check roll temperature
Use vacuum box to remove excessive additiveson the roll
High Coefficient Additives Increase additive formulation namely the slip levelof Friction Extrusion temperature Decrease extrusion temperature
Chill roll temperature Increase the chill roll temperatureTreatment level Decrease the level of treatment applied to the film
Problem Possible Cause(s) Possible Solution(s)
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High Coefficient Die gap Decrease the die gap
of Friction Resin density Use resin with a higher density
Low MD Elongation Extrusion temperature Increase extrusion temperature
Low Gloss Extrusion temperature Increase extrusion temperatureChill roll temperature Decrease the chill roll temperatureScreen pack Increase restriction
Resin density Use a resin with a higher densityResin melt index Use a resin with a higher melt index
Die gap Decrease the die gapAdditives Decrease the additive formulation
Low Stiffness Resin density Use a resin with a higher densityChill roll density Increase the chill roll temperature
Air gap Increase the air gap
Low MD Tear Resin density Use a resin with a lower densityStrength Chill roll temperature Increase the chill roll temperature
Extrusion temperature Decrease the extrusion temperatureAir gap Decrease the air gap
Extruder output/take up Increase output and/or take up speed
Resin melt index Use a resin with a lower melt index
Low MD Tensile Extrusion temperature Decrease the extrusion temperatureStrength Chill roll temperature Increase the chill roll temperature
Resin density Use a resin with a higher density
Die gap Decrease die gapExtruder output/take up Increase output and/or take up speed
Poor Barrier Resin density Use a resin with a higher density
Properties Chill roll temperature Increase the chill roll temperatureExtrusion temperature Decrease extrusion temperature
Air gap Increase the air gapScreen pack Increase restriction
Poor Haze Extrusion temperature Increase extrusion temperatureChill roll temperature Decrease chill roll temperatureScreen pack Increase restriction
Resin melt index Use resin with a higher melt indexDie gap Increase the die gap
Air gap Increase the air gapResin density Use resin with a higher density
Additives Decrease the additive formulation
Poor Heat Seal Resin density Use resin with a lower densityTreatment level Decrease the level of treatment being used
Resin melt index Use a resin with a higher melt indexAdditives Decrease the additives formulation
BP Solvay Polyethylene North America
3333 Richmond Avenue, Houston, Texas 77098-3099 Mailing: P.O. Box 27326, Houston, Texas 77227-7328Telephone: 1.800.231.6313 Fax: 713.522.2435 Technical Service: 1.800.338.0489 Customer Order Service: 1.800.527.5419www.bpsolvaype.com/na
TO THE BEST OF OUR KNOWLEDGE THE INFORMATION CONTAINED HEREIN IS ACCURATE. HOWEVER, NEITHER BP SOLVAY POLYETHYLENE NORTH AMERICA, NOR ANY OFITS AFFILIATES ASSUMES ANY LIABILITY WHATSOEVER FOR THE ACCURACY OR COMPLETENESS OF THE INFORMATION CONTAINED HEREIN. FINAL DETERMINATION OFTHE SUITABILITY OF ANY INFORMATION OR MATERIAL FOR THE USE CONTEMPLATED, THE MANNER OF USE, AND WHETHER THERE IS ANY INFRINGEMENT OF PATENTS ISTHE SOLE RESPONSIBILITY OF THE USER.
COPYRIGHT 2002, BP SOLVAY POLYETHYLENE NORTH AMERICA. ALL RIGHTS RESERVED. ISSUE DATE 7/2002.
Problem Possible Cause(s) Possible Solution(s)
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Poor Impact Resin density Use a resin with a lower densityResin melt index Use a resin with a lower melt index
Chill roll temperature Decrease the chill roll temperatureDie gap Decrease the die gap
Screen pack Increase restriction
Poor Transparency Extrusion temperature Increase the extrusion temperature
Chill roll temperature Decrease the chill roll temperature
Screen pack Increase restrictionDie gap Decrease die gap
Air gap Decrease air gapAdditives Decrease the additive formulation
Scratches Rolls not turning Check the dragCheck the roll speed and adjust accordingly
Check the balance
Shark Skin Low melt temperature Increase melt temperature
Apply heat to the die lipsNarrow die gap Increase the gap
Soft Roll Insufficient winding tension Increase the tension
Decrease the taperInsufficient lay-on pressure Increase the pressure
Stripes Excessive air knife pressure Decrease air pressurecreating extreme air discharge
Air pockets between film Increase the air knife pressure
and chill roll Reposition the blade
Wrinkles Flow variation from the die Adjust the barrel and die zonesAdjust the die gap
High winding tension Adjust the line
Non-uniform cooling Adjust web pinning
(stiff edges) Trim the web sooner
BP Solvay Polyethylene North America
3333 Richmond Avenue, Houston, Texas 77098-3099 Mailing: P.O. Box 27326, Houston, Texas 77227-7328Telephone: 1.800.231.6313 Fax: 713.522.2435 Technical Service: 1.800.338.0489 Customer Order Service: 1.800.527.5419www.bpsolvaype.com/na
TO THE BEST OF OUR KNOWLEDGE THE INFORMATION CONTAINED HEREIN IS ACCURATE. HOWEVER, NEITHER BP SOLVAY POLYETHYLENE NORTH AMERICA, NOR ANY OFITS AFFILIATES ASSUMES ANY LIABILITY WHATSOEVER FOR THE ACCURACY OR COMPLETENESS OF THE INFORMATION CONTAINED HEREIN. FINAL DETERMINATION OFTHE SUITABILITY OF ANY INFORMATION OR MATERIAL FOR THE USE CONTEMPLATED, THE MANNER OF USE, AND WHETHER THERE IS ANY INFRINGEMENT OF PATENTS ISTHE SOLE RESPONSIBILITY OF THE USER.
COPYRIGHT 2002, BP SOLVAY POLYETHYLENE NORTH AMERICA. ALL RIGHTS RESERVED. ISSUE DATE 7/2002.
Problem Possible Cause(s) Possible Solution(s)
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