Grantee Research Project Results
Final Report: Cleaner Manufacturing Process to Produce Dichroic Films and Particles for Textile Pigments and Dyes
EPA Contract Number: 68HERC21C0033Title: Cleaner Manufacturing Process to Produce Dichroic Films and Particles for Textile Pigments and Dyes
Investigators: Berg, Michelle
Small Business: NanoSonic Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2021 through August 31, 2021
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2021) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Toxic Chemicals
Description:
The objective of NanoSonic’s EPA SBIR program is to establish and commercially transition cleaner, environmentally friendly manufacturing processes for producing dichroic films and pigments without the use of water, and demonstrate they can be used to color fibers, fabrics and other materials. The value proposition of NanoSonic’s proposed pigment manufacturing approach is a drastic reduction in the water necessary to produce dichroic-based coloration materials and a significant reduction in the contaminants released into the environment during the bonding of dichroic colorants onto substrates such as fabrics and into materials such as foams and building materials.
Summary/Accomplishments (Outputs/Outcomes):
Upon completion of the Phase I program, NanoSonic demonstrated the ability to produce multilayered dichroic films by combining polystyrene (PS) and polymethylmethacrylate (PMMA) films with titanium dioxide interlayers to produce materials that reflect either yellow or pink/purple colors. The transmission spectra for these dichroic films are comparable to the theoretical transmission spectra for yellow and pink/purple materials produced by expensive semiconductor clean room vacuum deposition processes.
Through the use of cryomilling, NanoSonic was able to convert its dichroic films into particles with sizes on the order of microns. These particles were then chemically bonded to nylon / cotton, polyester, and fiberglass fabrics to demonstrate textile coloration utility. NanoSonic also melt-bonded multiple dichroic films to polyester and fiberglass fabrics to demonstrate a potential low-cost, roll-to-roll textile pigmentation process that may be pursued during a Phase II program.
After extensive rheological characterization, team partner Virginia Tech identified co-extrusion temperatures for producing multilayered dichroic films of PS and PMMA. Using its multiplier die sections, films with a target of 24, 48, and 96 alternating layers of PS and PMMA were extruded into single films at a processing temperature of 230°C. Further work is necessary to control the interlayer thicknesses and physical structure of the co-extruded thermoplastics to consistently achieve the desired dichroic spectral properties without the use of titanium dioxide interlayers.
Conclusions:
NanoSonic and Virginia Tech accomplished all of its Phase I technical and commercialization objectives during the base 6-month effort. A summary of these accomplishments is outlined below.
• Established commercially scalable, environmentally friendly processes for producing yellow dichroic films without the use of water using PMMA, PS, and TiO2. EPA team members have indicated that the production of yellow pigments generates the greatest amount of pollution (relative to other pigments and dyes).
• Established commercially scalable, environmentally friendly processes for producing pink/ purple dichroic films without the use of water using PMMA, PS, and TiO2.
• Demonstrated ability to cryomill dichroic films into polymeric particles (~10 to 100 micron diameter) and chemically bond those particles to textile fabrics for pigmentation without the use of water.
• Melt bonded yellow and pink / purple dichroic films to nylon / cotton and fiberglass fabrics to impart pigmentation using a solvent free, scalable roll-to-roll manufacturing process.
• Identified compatible processing temperatures for co-extruding PS and PMMA into thin films (~1.0 mm thick) after extensive rheological measurements.
• Co-extruded PS and PMMA thermoplastics into films with a target of 3, 24, 48, and 96 alternating layers using in-line multiplier die sections.
• Completed market commercialization report with Foresight Science and Technology, Inc. Foresight’s Technical and Business Assistance Service® (TABA) provides actionable information and recommendations that will help NanoSonic strategically position its technology in the appropriate market niche(s) during the Phase II SBIR program.
In addition to achieving its technical goals, NanoSonic worked with its Phase III commercialization partner Foresight Science and Technology, Inc. to complete its commercialization planning objectives. This involved creating a business model canvas to guide future commercialization efforts, defining NanoSonic’s value proposition to customers, and estimating price points for successful market entry. During a possible Phase II program, NanoSonic and Virginia Tech will work to refine the co-extrusion process of PS, PMMA, and TiO2 to produce dichroic films with tailored reflection colors, establish commercially scalable procedures for cryomilling the films into low-cost, recyclable polymeric pigments, and demonstrate the commercial utility of its dichroic films and polymeric particles for pigmenting dyeing fabrics. The dichroic materials will displace part of the current $33B global market for dyes and pigments, a market which is expected to grow at a compound annual growth rate of 5 percent between 2020 and 2027. The primary initial users of these products will be the manufacturers of dyed fabrics used in the garment industry that dominates the use of dyes and the consumption of water worldwide.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.