# Looking Beyond Pure Cellulose to Lignocellulose for Regenerated Continuous Spun Filaments

## TL;DR

Researchers made continuous fibers from unprocessed lignocellulose pulp, showing potential for sustainable textiles with minimal processing.

## Contribution

Producing continuous fibers directly from unbleached lignocellulose pulp without prior separation of components.

## Key findings

- LCP fibers had strengths of 114–173 MPa and moduli of 9–12 GPa, comparable to wool and lyocell fibers.
- Undissolved lignocellulose components did not hinder the spinning process, enabling continuous fiber production.
- X-ray diffraction showed low-to-mid-range fiber orientation values (<sin2 θ> of 0.2–0.5).

## Abstract

The need to use naturally abundant, renewable, and sustainable
precursors, such as lignin and cellulose, to produce technical textile
fibers for a range of applications is rapidly growing. Being able
to spin fibers directly from the biomass feedstock, without separation
and purification, could significantly reduce processing costs, energy
consumption, and pollution, and also retain carbon for subsequent
use in carbon fiber production and other applications. Going beyond
the approach of either spinning pure lignin, cellulose, or combinations
of the two, continuous regenerated spun fibers have been successfully
produced from dissolved and unbleached miscanthus grass pulp. The
rheological and microscopic properties of the spinning dope were fully
characterized as well as the structure and mechanical properties of
the spun lignocellulose pulp (LCP) fibers. The highly viscous spinning
dope had a zero-shear viscosity in the range 26–256 kPa·s,
which resulted in spun fibers with a rough surface texture, with some
undissolved lignocellulose components in the dope. The LCP fiber’s
orientation was determined using X-ray diffraction, displaying low-
to mid-range values of <sin2 θ> (0.2–0.5),
which was expected at the low draw ratios used to ensure fiber consistency.
Despite this, the filaments were found to have strengths in the range
of 114–173 MPa, similar to wool or wet viscose rayon, and moduli
of 9–12 GPa comparable to lower-range lyocell fibers. Interestingly,
the micrometer-scale undissolved lignocellulose components did not
inhibit the spinning process, allowing the production of what resembles
continuous natural fibers. This approach shows promise for generating
sustainable continuous spun fibers, without excessive pretreatment
of the precursor, for technical textiles from lignocellulose pulps.