1. Cast Stretch Wrap Film Marcel van Enckevort SABIC Polyethylenes BV
Market Analyses Update
Stretching the Limits
“The effect of Extrusion and Casting process variables on Stretch Film Performance”
Marcel van Enckevort
SABIC Polyethylenes BV
Disclaimer
All information supplied by or on behalf of SABIC EuroPetrochemicals companies in relation to its products, whether in the nature of data, recommendations or otherwise, is supported by research and believed reliable, but SABIC EuroPetrochemicals companies assumes no liability whatsoever in respect of application, processing or use made of the afore-mentioned information or products, or any consequence thereof. The user undertakes all liability in respect of application, processing or use of the afore-mentioned information or product, whose quality and other properties he shall verify, or any consequence thereof. No liability whatsoever shall be attached to SABIC EuroPetrochemicals companies for any infringement of the rights owned or controlled by a third party in intellectual, industrial or other property by reason on the application, processing or use of the afore-mentioned information or products by the user.
© 2003 SABIC Polyethylenes BV

2. Introduction
Stretching the . . .
As a converter you can improve your economies of scale by stretching the output and speed to the limits of your cast stretch lines.
Limits
Equipment
Application
Resins

3. Introduction Experimental set-up Approach Results Conclusions
Outline
Introduction
Experimental set-up
Approach
Results
Conclusions
Comparison

4. Cast Stretch Wrap Film segments
Manual Stretch
100 – 150%
40% Market share
Automatic Stretch
150 – 250%
48% Market share
Power Stretch
> 250%
12% Market share
Photos: ITW MIMA Stretch Packaging Systems

5. Cast Stretch Wrap Film Cost Structure
Source: SMS Folientechnik GmbH

6. Maximum pre-stretch level up to 250%
Facts & Figures
Almost 90% of the stretch film demand is in hand wrap and machine wrap applications
Maximum pre-stretch level up to 250%
More than 80% of your film cost price is determined by the resins
End users are looking for the lowest price!

7. Are you fulfilling your potential?
Are you using optimal outputs/speed?
Nowadays modern stretch film lines can run at higher speeds (up to 600 m/min)
Older stretch film lines can potentially run faster than being done today!
Note: speed also determines the end film properties
Did you optimise line settings to use the full potential of the resins?
Are you using fit for purpose resins?

8. Approach
Butene-based SABIC® LLDPE 318B (2.8/918)
A state-of-art cast stretch film line
Real world conditions
3-layer film concept A/B/C with 15% VLDPE in cling layer and 25% trim recycle in the core
Experimental design
15 experiments in 2 days
Easy adjustable variables

9. Cast2020: Settings Dimension Value Output > 1000 kg/h Winding speed
500 m/min
Die gap
0.6 mm
Film thickness
20 µm
Layer distribution
15/70/15 %
Recycle in core layer
25%
Photo: SMS Folientechnik GmbH

10. Cast2020: Settings – Cont. Variable Range Melt Temp. 250 – 290 °C
Chill roll Temp.
15 – 25 °C
Vacuum box
2 – 4 cm H2O
Photo: SMS Folientechnik GmbH

11. SABIC® C4-LLDPE Film properties
Improved by changing settings:
Tear resistance TD with 15%
Puncture resistance with 60%
Ultimate pre-stretch level with 37% (from 230 to 340%)
Not influenced by the settings:
Optical properties (Gloss, Haze)
Cling
Elastic recovery (snap back)
Stress retention (bundling force)

12. Ultimate Pre-stretch level (HighLight)

13. Real world testing Semi-automatic Stretch Wrapper
ROBOPAC Rotoplat 705 PVS
Setting
Maximum
Pre-stretch
400%
Turntable speed
15 rpm
Wrapping speed
60 m/min

14. Real world testing – Cont.
BUT(ENE)
Looking for the limits we found several holes and film ruptures!
we also found consistent pre-stretch levels up to
400 %

15. Achieve pre-stretch levels up to 400%!!
Conclusions
Apply optimal processing conditions to utilise the potential performance present in your C4-LLDPE based films
Take advantage of the cost price benefits from maximising the use of C4-LLDPE
Achieve pre-stretch levels up to 400%!!

16. Introduction Experimental set-up Approach Results Conclusions
Outline
Introduction
Experimental set-up
Approach
Results
Conclusions
Comparison

17. What about the SABIC® C6-LLDPE?
compared SABIC® C6-LLDPE (and C4-LLDPE) with metallocene based-C6-LLDPE and with C8-LLDPE
Cast2020 cast film line
3-layer film concept A/B/C concept with 15% VLLDPE in cling layer and 25% recycle in the core
Melt temperature, chill-roll and vacuum box on midpoint settings

18. Results

19. And there is still room for improvement!
Conclusions
Utilising C6-LLDPE can:
Improve relevant film properties (e.g. Tear Resistance, Puncture Resistance and cling)
$AV€ on the cost of VLDPE (up to 50%) , using C6-LLDPE in the cling layer!
Easily obtain pre-stretch levels of 250%
And there is still room for improvement!

20. Enjoy the use of SABIC® LLDPE…..
Finally
Explore the limits of processing traditional C4 and C6 based LLDPE resins on your extrusion lines
Apply fit for purpose resins in your film structures
Enjoy the use of SABIC® LLDPE…..

21. Stretching the Limits

22. Acknowledgement
SMS Folientechnik GmbH, Vienna
Polychem Laboratory
HighLight Industries
De Witt ROBOPAC, The Netherlands