Principal investigator: Nicolas Alvarez

University: Drexel University

Industry partners: eCO2Dye, LLC

UHMWPE fibers offer incredible tensile properties to mass ratios and are finding increased use in commercial applications. For example, a recent market assessment of UHMWPE fibers projects a maintained growth rate of 15% over the next five years. While the properties of UHMWPE fibers set them apart from other textile materials, UHMWPE poses some technological challenges that limit its wide-spread adoption. For example, UHMWPE is considered very difficult to color due to its high hydrophobicity and crystalline content. We propose and demonstrate a new method of using sc-CO2 to dissolve and disperse dyes into the amorphous domains of as-spun UHMWPE fibers prior to drawing. Preliminary data clearly shows that our method is very successful at increasing the concentration of dye into the final fiber to achieve deep, saturated colors. Our process is significantly safer and environmentally friendly than traditional textile dyeing processes which use hazardous organic solvents, and has the added benefit of component recyclability, cost effectiveness, and decreased processing times. This project is divided into four goals:

  1. develop best dyes and formulations for amorphous PE
  2. determine the best as-spun fiber crystalline structure that maximizes dye uptake
  3. determine the effect of dye on mechanical properties
  4. demonstrate large scale fiber dyeing

This project is a collaboration between industrial partner eCO2Dye and the Alvarez Research Group at Drexel University. Many of the dyeing experiments will be carried out at eCO2Dye’s facilities in Allentown, PA using their CO2 pressure vessels. Drexel will be responsible for the generation and characterization of fibers. This project will create an important market for the eCO2Dye line of product and partly support Ph.D. student Zachary Hinton for his final year, and add valuable data to his thesis on sc-CO2 interfacial phenomena.