Electrostatic Fiber Individualizer/Separator for Cotton

Physical Sciences : Mechanical

Available for licensing


  • Mourad Krifa , University of Texas at Austin
  • Hao Wu , University of Texas at Austin

Background/unmet need

In the global cotton trade, quality of cotton as in measured physical characteristics is closely associated with pricing. Among all measured characteristics of cotton and most other fibrous materials, fiber length has always been considered as the most crucial. The market value and end-use of the fiber along with the processes adopted for its transformation are largely determined by its length properties.

Unfortunately, reliably characterizing the length distribution in a bulk fiber sample is rather challenging, and existing solutions present multiple biases and shortcomings. The first major challenge stems from the intrinsic variability of single fiber lengths, which is typically determined by complex interactions involving genetic, environmental, and processing factors. As a result, obtaining a representative sample from a bulk fiber lot is a problem.

Currently, there are two major principles used to overcome this problem: fiber bundle sampling, and single-fiber measurement. While the former leads to bias of the length distribution toward the long fibers, the latter leads to fiber breakage, thus biasing the measured length distribution toward shorter fibers.

Invention Description

A group in the School of Human Ecology at The University of Texas at Austin has invented a novel fiber sampler/individualizer method that uses electrostatic forces to separate bulk fiber samples into individual fibers and an imaging system to capture individual fibers traveling toward the grounded or negatively charged collector. This method provides an almost completely unbiased characterization of fiber length. It can also be used in other physical tests, such as strength, micronaire, and color, that can benefit from the damage-free individualization scheme.


    A fiber length measurement with reduced biases can be used by those involved in the production and marketing of cotton to evaluate, improve, and preserve the genetic length distribution. This will ultimately result in Texas and US cottons that are more competitive and higher valued in the global textile markets.


  • Non-contact fiber individualization and straightening
  • Electrostatic field used to efficiently overcome cohesive inter-fiber friction

Market potential/applications

Fiber classing and testing equipment; cotton seed optimization and genetic engineering

Development Stage

Lab/bench prototype

IP Status

  • 1 U.S. patent application filed