Bottle Applications
Figure 3 shows the storage temperature dependency on the water vapor barrier performance of EcoSield, EcoSieldWO and the PET bottle. As can be seen, EcoSield-WO has the same water vapor barrier performance as the PET bottle at temperatures of up to 45°C. Thus, EcoSield-WO will be suitable for water vapor sensitive contents similar to a PET bottle. With regard to biodegradability, Toyo Seikan is looking at two points, namely reduction of plastic waste and ease of disposal for each household to achieve a positive contribution to society. EcoSield is biodegradable under certain circumstances. Figure 4 shows the degradation results in an electrically powered house-hold-composter1, as it is used in Japanese households. As the picture shows EcoSield can be broken down within 32 hours in such a ‘home-composting unit’1. In addition, the biodegradability was determined by measuring the carbon dioxide generated (ISO 14855 part 2) by the reaction with microorganisms using standard compost and EcoSield at 58°C. EcoSield can be biodegraded within 45 to 50 days, which means that the biodegradability of EcoSield is rapid in controlled compost conditions. With regards to these results, the advantages in disposing of PLA bottles make it possible to promote a change in the way societies approach waste collection and processing. If this bottle becomes more widely used throughout the world the environment would naturally become cleaner. Toyo Seikan seriously hopes that the EcoSield technology will be able to contribute to reducing global warming as much as possible. www.toyo-seikan.co.jp/e
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Over flow volume reduction (%)
the gas barrier performance of EcoSield and EcoSieldWO compared to a PET bottle. The barrier performance is only 1/8 (water vapor) and only 1/9 (oxygen) of that of PET. The EcoSield-WO however, has a slightly improved water vapor barrier performance over the PET bottle. Compared to existing PLA bottles an excellent gas barrier advantage for both water vapor and oxygen can be seen. With these barrier enhancements EcoSield-WO is suitable for oxygen and water vapor sensitive contents, just as a PET bottle.
PLA bottle Purchased from Market
20 15 10 5 0
1.0
2.0
3.0
4.0
5.0
d-isomer content (%) Sample condition: Mold temperature 30 ºC Storage condition: 55 ºC Storage period: 7 days
Fig. 3: Gas barrier property of water vapor
Water vapor permeation (g/m2 day)
PLA Bottles
Fig. 2: Thermal stability
30
EcoSieldTM (Standard)
25
EcoSield-WOTM (High Barrier)
20
PET
15 10
5 0
0
10
20
30
40
50
Storage temperature (ºC) EcoSield-WOTM (Under development)
Table 1: Gas barrier performance
Bottles
H2O
O2
PET
1.0
1.0
1/8x
1/9x
1.3 x
1.0 x
EcoSieldTM
(Standard: PLA only)
EcoSield-WOTM (High Barrier)
EcoSield-WOTM (Under development) Barrier performance has been improved by Toyo Seikan’s unique gas barrier technology.
After 4 treatments (16Hr)
Start
After 8 treatments (32Hr)
End After 20 treatments (80Hr)
After 12 treatments After 16 (48Hr) treatments (64Hr)
1: This has nothing in common with what is usually referred to as “home composting”. In such an electric home-composter, temperatures of approx. 80°C are applied to reduce the volume of kitchen waste.
Fig. 4: Degradation by ‘home composting’1 process
bioplastics MAGAZINE [05/08] Vol. 3
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