Issue 05/2015

Barrier
The rate of moisture absorption in Plantic is controlled
and limited due to the water resistance of the barrier skin
materials. Independent tests have shown that the barrier
performance remains below instrument detection limits
(typically 0.05 cm³/m 2 /day) for more than 7 days. Figure 2
demonstrates this for a Plantic sample, equilibrated at
75 % RH, and then exposed to 90 % RH. After 8 days there
is no measurable change in the OTR, which remains below
the instrument detection limit.
The barrier performance of Plantic is even better at
lower temperatures, as shown in figure 3. There is a factor
of 3 decrease in the OTR at 50 % RH as the temperature
is reduced from 20 °C to 5 °C. This is an important factor
in the extended shelf life of fresh meat and poultry stored
under refrigerated conditions.
PLANTIC eco Plastic extends the shelf life of fresh
food.
Plantic have conducted a number of external trials
at certified, independent laboratories to determine the
actual shelf life of fresh meat, such as mince, chicken and
fish compared to conventional polypropylene (PP) barrier
trays currently used in the market. The same top web was
used for all samples in both Plantic and PP trays.
The results also indicated that samples packed in
Plantic trays maintained the original colour for both
chicken and sausage meat for longer than those packed
in conventional PP trays. Shelf life extension was based
on a combination of factors, including Total Plate Count,
Coliform, pH, odour and colour assessment according to
NATA regulations.
The chicken packed in Plantic trays demonstrated a
40 % increase in shelf life and sausage meat packed in
eco Plastic trays demonstrated 15 % increase in shelf life.
Both products maintained their originally packaged colour
(less browning due to oxidation) for longer in eco Plastic
trays than those packed in PP trays.
www.kuraray.co.jp/en
www.plantic.com.au
3·25µ/m 2·day·atm]
OTR [cm
Figure 1: Effect of relative humidity on oxygen transmission rate for
a selection of commercial barrier polymers.
OTR cm 3 /m 2 /day
100.0
10.0
1.0
0.1
0
0.05
0.04
0.03
0.02
0.01
0
-0.01
-0.02
0
EVOH-32 %
EVOH-44 %
MXD6
Plantic
20 40 60 80 100
% RH
Specimen A, 0.46 mm
Specimen B, 0.47 mm
1 2 3 4 5 6 7 8
Days after RH change
Figure 2: Effect of a change in external relative humidity from 75 %
to 90 % on the barrier performance of Plantic.
(Test Method: ASTM F1927-98: 23 °C (± 0.2 °C),
RH as specified ± 3 %, Test gas 100 % Oxygen)
Table 1: Comparative barrier performance of packaging film
materials.
Material
OTR
cm³/m²/day
25 µm, 23 °C, 50 % RH
WVTR
g/m²/day
25 µm, 38 °C, 90 % RH
LDPE 6,500 18
HDPE 2,300 6
PP 2,300 11
PLA 600 300
PVC 200 46
PET 40 20
Nylon 6 32 160
MXD6 2.0 80
PVDC 2.0 3
EVOH 44 % 1.0 20
EVOH 32 % 0.2 60
Plantic 0.5 150
Figure 3: Effect of temperature on the barrier performance of
Plantic.
OTR [cc·25µ/m 2·day·atm]
1
0.1
0.01
0
5 °C
10 °C
15 °C
20 °C
20 40 60 80
% RH
bioplastics MAGAZINE [05/15] Vol. 10 41