Sigma Technologies International, Inc.
10960 N. Stallard Place, Tucson, AZ 85737
•Mwww.sigmalabs.com
DESCRIPTION OF THE TECHNOLOGY
With support from the Environmental Protection Agency's
(EPA) Small Business Innovation Research (SBIR) Pro-
gram, Sigma Technologies International, Inc., developed
inexpensive, high-speed, inline technology and equipment
for the treatment (i.e., functionalization) of film surfaces
to promote adhesion of solventless and aqueous-based inks.
Surface functionalization is achieved by an appropri-
ate combination of plasma treatment and thin (submi-
cron) acrylate coating within a vacuum environment.
Functionalization is performed inline at high speed us-
ing Sigma Technologies' proprietary equipment. The
process begins with plasma treatment of one surface of
the plastic film using a moderate energy flux with a
suitable gas mixture. As the plastic film continues
through the web-processing machinery, it can be met-
alized and coated or coated directly with a very thin
layer of an acrylate-based monomer that is 100 per-
cent active (i.e., no solvents). The monomer is depos-
ited on the surface of the plastic film, then passed in
front of an electron beam where the monomer is rapidly
and completely polymerized. The functionalized film
then is ready for printing, labeling, or other processing.
Sigma Technologies also has developed radiation-curable,
acrylate monomers that either repel or attract water.
Monomer blends can be tailored to meet the specific sur-
face energy requirements of the client.
SIGNIFICANCE OF THE TECHNOLOGY
This technology offers the environmental benefit of re-
ducing the dependence of the packaging film printing
industry on solvent-based inks. Use of solvent-based inks
results in the release of volatile organic compounds
(VOCs)—particularly toluene—to the atmosphere. Tolu-
ene has been near the top of the Toxic Release Inven-
tory list in recent years, with tens of millions of pounds
released annually. Solvent-based inks are responsible for
approximately 50 percent (by weight) of the VOCs emit-
ted from a typical printer, and VOCs are regulated as
criteria air pollutants under the Clean Air Act. Sigma
Technologies' surface functionalization technology pro-
vides packaging film industry printers and converters with
a pollution prevention alternative to the use of solvent-
based inks. Use of this technology will eliminate the re-
lease of VOCs associated with the use of solvent-based
inks. It also eliminates the need to dispose of waste sol-
vent-based inks as hazardous wastes.
Sigma Technologies has developed inexpensive, high-speed, inline technology and equipment for sur-
face functionalization of plastic film that promotes adhesion of aqueous-based and solventless inks.
The technology eliminates the use of solvent-based inks by packaging film printers, preventing the
release of VOCs to the atmosphere as well as the need to dispose of waste solvent-based inks as hazard-
ous wastes.
4- Functionalization of packaging films increases the metal "sticking coefficient" for metallized plastic
packaging film, reducing the amount of metal wasted and the resulting disposal costs.
-f The acrylate coating technology can be tailored to provide almost any surface energy desired on a
plastic film substrate.
4- SBIR funding helped Sigma Technologies obtain R&D commitments from major players in the packag-
ing film industry to accelerate commercialization of this technology.
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Polymer Film Web
From Unwind Roll
Coated Polymer Film
Web To Wind Roll
Curing Device
Plasma
Treater
Metallization
Degas Vessel With
Liquid Monomer
Schematic of vaccum deposition of a polymer coat-
ing. First, the film is plasma treated to promote adhe-
sion of the vaccum deposited coating. A reactive liq-
uid monomer (one or more double bonds) then is
degassed, atomized into a flash evaporator, converted
to vapor, delivered to the film surface through a nozzle,
condensed back into a liquid on the moving film sur-
face, and finally cross-linked to polymer with an e-
beam gun or UV lamp. A polymer layer can be depos-
ited by itself, or before and/or after a metallized or
sputtered layer.
In addition to eliminating the use of solvent-based inks,
Sigma Technologies' surface functionalization process is
more efficient for clients who metallize plastic packaging
film following plasma treatment. Functionalization of
packaging films increases the "sticking coefficient" for
the metal in comparison to untreated film. That is, the
percentage of the evaporated metal that condenses and
adheres to the surface of the film is slightly higher for
films that have been plasma treated. More efficient metal
deposition means less metal is wasted, and waste disposal
costs are reduced.
COMMERCIALIZATION SUCCESS
EPA SBIR funding significantly contributed to the suc-
cess of Sigma Technologies' commercialization efforts. The
Phase I project helped compile credible data and im-
portant findings, which resulted in R&D commitments
from clients who are major players in the packaging
film industry to run concurrently with the Phase II EPA
SBIR effort. The SBIR funding, combined with the pri-
vate sector efforts, helped Sigma Technologies to overcome
technical and financial obstacles during Phase II and
achieve successful commercialization of its equipment de-
sign and technology concept.
COMPANY HISTORY
Sigma Technologies International, Inc., is a technology
company that provides a broad range of products and
services. Sigma manufactures innovative turnkey coat-
ing and surface treatment systems for functionalizing
material surfaces, and for producing multilayer thin-film
coatings. The company also designs and manufactures
instrumentation for customers in the optics, packaging,
and energy storage markets. These include state-of-the-
art optical densitometers for measuring optical density,
coating thickness, and electrical resistivity of thin films;
specialty power supplies; and partial-discharge data ac-
quisition and analysis systems.
EPA's Small Business Innovation Research (SBIR) Program was created to assist small businesses in
transforming innovative ideas into commercial products. The SBIR Program has two phases—Phase I is
the feasibility study to determine the validity of the proposed concept and Phase II is the development of
the technology or product proven feasible in Phase I. EPA also offers Phase II Options to accelerate the
commercialization of SBIR technologies and to complete EPA's Environmental Technology Verification
(ETV) Program. For more information about EPA's SBIR Program and the National Center for Environmental
Research, visit http://www.epa.gov/ncer/sbir.
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