The Effect of Retort Conditions on Clear High Barrier Laminated Structures

Transcription

1 The Effect of Retort Conditions on Clear High Barrier Laminated Structures Celplast Metallized Products Ltd. Presented at the AIMCAL Fall Technical Conference October, 2005

2 Outline Retort pouch markets Clear barrier retort film technology Clear barrier laminations & retorting trials Barrier test results Conclusions

3 Retort Pouch Markets Drivers to replace cans & glass jars: Lighter weight Safer - no sharp edges Faster heating leads to more even cooking & better taste

4 Retort Pouch Markets Typical 4-ply MRE foil retort pouch structure: Polyester Ink Adhesive Nylon Adhesive Aluminum Foil Adhesive Cast Polypropylene

5 Retort Pouch Markets Drivers to use clear retort pouches: Visibility of product Microwavable Use with metal detectors Use with RFID tags

6 Retort Pouch Markets Several different products available on market: Silicon oxide coated PET Silicon oxide coated nylon Aluminum oxide coated PET Poly (acrylic acid) coated PET PVdC coated PET EVOH blown film

7 Retort Pouch Markets Drivers to use oxidecoated clear retort films: No yellowing Environmentally acceptable No retort shock Excellent chemical & odor resistance

8 Retort Pouch Markets Drivers to use solventless adhesives: Rising solvent costs Rising energy (dryer) costs EPA requirements Lower overall material usage

9 Retort Pouch Markets Typical 4-ply clear barrier retort pouch structure: Polyester Ink Adhesive Oxide-coated Polyester Adhesive Nylon Adhesive Cast Polypropylene

10 Retort Pouch Markets Possible 3-ply clear barrier retort pouch structures: Polyester Ink Adhesive Oxide-coated PET Adhesive Cast Polypropylene Polyester Ink Adhesive Oxide-coated Nylon Adhesive Cast Polypropylene

11 Clear barrier retort film Rewinder technology Unwinder Plasma pretreatment Electron beam evaporation

12 Clear barrier retort film technology Silicon-oxide coated films: Available on both nylon & PET substrates Improved processability Widely accepted in many packaging applications Excellent flex-crack resistance (Gelbo flex tests) compared to aluminum-oxide coated films

13 Clear barrier retort film technology Oxygen Permeation After Retorting And Gelbo Flexing for 48 g PET Films in Solvent-based Laminations OTR, 23 C post retort post retort 5x post retort 10x post retort 50x SiOx PET(1) SiOx PET(2) AlOx PET (1) AlOx PET (2)

14 Clear Barrier Laminations and Retorting Trials Structures evaluated: #1 48 g PET / SiOx-coated 48 g PET / 60 g nylon / 3 mil CPP #2 48 g PET / SiOx-coated 48 g PET / 3 mil CPP #3 48 g PET / SiOx-coated 60 g nylon / 3 mil CPP

15 Clear Barrier Laminations and Retorting Trials Rohm & Haas adhesives evaluated: Solventless aliphatic PUR inner plies Solvent-based aromatic PUR outer plies Henkel adhesives evaluated: Solventless aliphatic PUR #1 inner ply Solventless aliphatic PUR #2 outer plies

16 Clear Barrier Laminations and Retorting Trials Retort test conditions - Rohm & Haas: Carried out at 121 C for 1 hour Retorted both laminated strips and waterfilled pouches suspended in retort chamber Retort test conditions - Henkel: Carried out at 121 C for 1 hour Retorted pouches only One set filled with water, one set with vegetable oil

17 Barrier Test Results Oxygen barrier testing: Carried out at 23 C, 50%RH Samples tested on MOCON 2/21 and Lyssy OPT oxygen transmission rate test units Water vapor barrier testing: Carried out at 37.8 C, 90%RH Samples tested on MOCON Permatran W and Lyssy L water vapor transmission rate test units

18 OTR Test Results R&H

19 WVTR Test Results R&H

20 OTR Test Results - Henkel

21 WVTR Test Results - Henkel

22 Conclusions Silicon oxide coated PET performed well in both 3-ply and 4-ply structures Silicon oxide coated nylon barrier was compromised by 2-5x after retorting Vegetable oil in pouches was more aggressive in compromising barrier properties than water in pouches

23 Conclusions 3-ply pouches of PET/SiOx-PET/CPP structure exhibited more stress whitening after retorting than nyloncontaining structures Aliphatic solventless adhesive used between all plies gave better post-retort WVTR properties than structures with aromatic solventless adhesive; OTR was similar in both structures

24 Acknowledgments Tom Mueller of Rohm & Haas Grant Kenion of Henkel Adhesives Scott Whiteside of Clemson University

25 THANK YOU! Any questions?

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