CastFilm Troubleshooting PE

8/12/2019 CastFilm Troubleshooting PE

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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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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.


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


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


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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






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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


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






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CastFilm Troubleshooting PE