3MTM is investing $200 million in new plastic film production as its
targets a major business opportunity in solar and other renewable energy
The company recently completed a manufacturing expansion in Singapore for 3M
ScotchshieldTM Film, a
leading solar film critical to the manufacturing of crystalline silicon
photovoltaic (PV) modules. A look at recent patents approvals shows that the
Minnesota-based technology powerhouse is also quietly developing new products aimed
at reducing cost and improving performance of solar cells
"3M draws upon decades of experience producing similar
materials for other industries and applies this heritage to our line of
renewable energy products," says Scott Norquist, manager of Energy
Generation for the 3M Renewable Energy Div.
3M pioneered solar films 25 years ago, when scientists first
developed solar energy and mirror films. The company also has significant
experience in developing products for long-term exposure to outdoor
environments and has substantial capabilities in weathering technologies.
In early 2009, 3M formed
a Renewable Energy Division to coordinate applicable products across the
company's 40-plus core technologies. It falls within 3M's Industrial and
Transportation Business and focuses on energy generation and energy management.
3M offers films, tapes, coatings, encapsulants, sealants and adhesives for
solar energy, wind energy, geothermal and biofuel businesses
3M has made several breakthroughs in concentrating light
with inventions such as 3M Solar Concentrator Panels. In addition, 3M Mirror
Films demonstrate potential to provide cost savings over similar glass-based
Scotchshield Film 17 utilizes a multilayer construction consisting of an
outer fluoropolymer film bonded to a proprietary PET film, which is bonded to
EVA film to complete the multilayer backsheet. This inner EVA layer of the
backsheet bonds to EVA cell encapsulants during the PV module lamination
patent awarded Dec. 29 to 3M Innovative Properties Co. shows the significant
technical firepower 3M is putting into this market. The patent describes a
multilayer film intended to improve protection of the back of a solar cell
while overcome problems associated with previous designs such as high cost or
difficulty in applying laminates.
The 3M multilayer film in the patent includes a polyester
intermediate layer and outer layers of semi-crystalline fluoropolymer with a
tensile modulus of less than 100,000 psi and an olefinic plastic, such as
polypropylene. The layers could be produced through a conventional coextrusion
process or via thermal lamination.
One of the key aspects of the new approach is the
preshrinking of the polyester layer prior to thermal lamination. "Pre-shrinking
of the film after the addition of other layers can become exceedingly difficult
especially if one or more of the additional outer layers has a softening or melting
point that is within the temperature range required to pre-shrink the
intermediate layer," according to the 3M inventors.
The thickness of the individual layers within the multilayer
film can be varied based on the requirements. 3M says it expects the outer
layer of fluoropolymer will be from about 0.5 to 5 mils, preferably 1 to 2 mils
thick; the intermediate layer will be from about 1 to 10 mils, preferably 2 to
4 mils; and the outer polyolefin layer will be from 1 to 20 mils or greater.
Preferably it is 10 mils or greater.
3M is not the only American corporate giant making a major
move in the photovoltaics area. DuPont said it expects
its sales in solar energy to exceed $1 billion by 2012.
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