Issue 04/2018

Basics
By:
Jesper van Berkel, Technical Application Manager, Synvina
Amsterdam, The Netherland
The 2 % and 5 % concentrations were selected for testing
following the EPBP protocol at PTI Europe, which comprises
the typical steps of a recycling process at 5kg-scale. These
steps are outlined below with some of the critical control
points.
• Bottle grinding g Dust formation
• Flake washing & Drying g Flake and/or water
discoloration, sticking
PEF in PET T g, mid
T m, peak
0 % 79 °C 249 °C
2 % 79 °C 248 °C
5 % 78 °C 247 °C
10 % 78 °C 245-247 °C
25 % 76 °C, 86 °C 207 °C, 240-246 °C
• Re-extrusion into pellets g IV loss, side products or
fumes
• Solid State Polymerization g IV build, sticking of pellets
• Injection into plaques/bottles with 50 % vPET g
Transparency, color, bottle properties
PEF in RPET (plaques following EPBP route with 50 % vPET)
2x
g
PEF Molecule
PET Molecules
{
None of the steps in the recycling process were found to
display surprising phenomena in the presence of PEF, and all
intermediate and final intrinsic viscosity measurements yielded
comparable values. The only notable difference was that for
the 5% loading the coloration of final plaques, as expressed by
Δb* = 2.1 compared to the PET reference, was higher than the
acceptable range of Δb* = 1.5. This is an aspect which we expect
to improve with further improvements in PEF resin color. 1.5 L
Bottles could be blown of the final resin, yielding properties as
per the table below.
Conclusion
PEF can serve as a high value bioplastic material for
applications where PET alone is not sufficient, and opposed
to other barrier technologies this value can be retained when
the bottles are recycled. Although yet to be demonstrated at
scale, this can offer many opportunities; PET bales with nonrecyclable
barrier bottles can be avoided, while PET bales with
PEF may be used to reduce haze formation or as a source of
separately accumulated PEF for individual rPEF campaigns
with high value output. Ultimately, a separate stream of PEF
bales can be created for an effective after-use economy.
[1] H. Ma, M. Hibbs, D.M. Collard, S. Kumar, D.A. Shiraldi, Macromolecules
2002 (35), 5123-5130
www.synvina.com
Property
(1.5L 43g
bottle)
Final
composition
Burst
Pressure
Vol incr. at
burst
Thermal
stability
Drop test
vertical 4°C
Drop test
vertical 22°C
Top Load
@1.0 mm
deflection
Method
Mass
balance
Linear
increase
Linear
increase
4.25 vol CO 2
,
24h 38°C,
Base pushup
1.8 m,
vertical
bottom
down, 72h
1.8 m,
vertical
bottom
down, 72h
Typical
Result
PET
2% Route 2 5% Route 2
PET+
1% PEF
PET+2.5%
PEF
11.0 bar 11.8 bar 11.5 bar
565 mL 594 mL 565 mL
-4.0 mm -4.2 mm -4.1 mm
8/8 OK 8/8 OK 8/8 OK
8/8 OK 8/8 OK 8/8 OK
Empty 225 N 240 N 225 N
bioplastics MAGAZINE [04/18] Vol. 13 51