Page 58 - Plastics News October 2016
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Technology corrosion problems, while limiting PID issues associated
with the use of EVA encapsulants. Better long-term
DOW’s ‘ENGAGE’ POE weathering performance enables better durability and
power output for the life of the module. The refractive
Dow Chemical’s polyolefin elastomer (POE) technology index of the film is very close to that of glass, reducing
used for critical PV module encapsulation applications refractive losses off of the glass-polymer interface and
under its ‘ENGAGE’ POE brand are designed to provide maximizing light transmission to the active cell material.
improved electrical performance and moisture resistance. In addition, it contains no liquids that can cause hydrolysis
As a result they meet increasing demand for longer or lead to bubble formation, thus eliminating the
energy production life and better durability and limit formation of acetic acid that could damage lamination
the impact of Potential Induced Degradation (PID) and equipment and modules.
premature module failure and replacement. PV modules
have typically been encapsulated with a wide-range of
ethylene-vinyl acetate (EVA)-based materials that have
lower upfront costs than other forms of encapsulant. How bacteria could help industry
However, numerous technical studies have shown
limitations of EVA in mechanical and thermal properties, recycle PET into bioplastic
water ingress and the production of acetic acid that can
lead to premature module failure. More recently, studies An initiative funded by the European Union is working
have shown the use of EVA-based encapsulants has been to recycle petroleum-based PET and polyurethane
linked to PID, which occurs when the module’s voltage into bio-based plastics through the use of enzymes and
potential and leakage current drive ion mobility within bacteria. Horizon, the research and innovation magazine
the module, due to moisture ingress and other factors of the European Union (EU), recently wrote about
permeating the EVA. the 7.05 million Euro
(about $7.8 million)
Producers of PV modules are demanding modules with P4SB project. The
longer energy production life and better durability and article also touches on
Dow Elastomers, a business unit within Dow, is supplying the difficulty reclaimers
ENGAGE POE as a quality material to meet market face competing against
requirements. Extensive laboratory and field testing by low virgin plastic prices.
the company has shown that PV modules manufactured
using ENGAGE POE-based encapsulant film can achieve Through the project, researchers are exploring the
improved performance results in terms of increased use of enzymes to break down PET and PU into their
power generation, module longevity and durability. The monomers, which will then be fed to genetically
POE-based encapsulant film offers lower WVTR (Water engineered bacteria to create a building block for
Vapor Transmission Rate)/moisture resistance eliminating a bio-based and biodegradable plastic. One project
partner hopes to develop a bioplastic substitute
for PU currently used in furniture, footwear and
electronics, and another is developing a bio-based
glue for food labels. "If recycling innovations like
plastic-eating bacteria are successfully scaled up,
then the value of plastic waste will increase along
with the economic incentive to recycle," according
to the article. "This could create a system less reliant
on virgin plastic and help recyclers compete during
[periods of] low oil prices." The four-year project
began in April 2015 and is scheduled to go through
March 2019.
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