DuPont ™ Sorona® polymer

Technical Information

DuPont™ Sorona® polymer: The only high-performance fiber made with renewable resources.

DuPont™ Sorona® polymer provides a unique combination of benefits to a

wide variety of applications. This advanced, value-added polymer
represents a major new mix-enrichment offering, with the potential for
growing into a significant market over the next ten to twenty years.
A unique molecular structure
DuPont™ Sorona® polymer is a unique polymer based on 1,3 propanediol (PDO). Its
beneficial properties are derived from a unique, semi-crystalline molecular structure
featuring a pronounced “kink,” as shown in Figure 1.

When stress is exerted on the molecule, strain deformation occurs first in its crystalline,
lower modulus regions. As stress is released, the crystalline structure locks in, allowing
a complete recovery to the initial shape. In conjunction with this distinctive
characteristic, fibers made with Sorona® offer additional advantages over both polyester
(PET) and nylon: it has a softer feel and supports easier, more versatile dyeability with
excellent washfastness and UV resistance.

Sorona® polymer is fiber-grade, which means it has a uniform micro-structure and a high
molecular weight that enhances processing. It can be spun into fiber or made into fabric in
Figure 1. Sorona® 3GT properties derive from many existing facilities that now process PET. Because Sorona® polymer is manufactured in
its unique molecular structure. a continuous process, the variation of polymer properties is limited. As a result, processing
problems and waste generation are minimized, leading to increased productivity.

Key technical features and benefits

1. Softness (a micro-denier feel at greater than one denier)
Both flat and textured yarns may be created from Sorona® polymer, bringing an
exceptional new level of softness to any fabric at an easily-workable denier.

The stress-strain tests demonstrate that flat yarns made with Sorona® fibers are softer
than either polyester or nylon, at the same denier, because less effort is required to
bend Sorona® fibers.

In addition to enhancing the softness of apparel fabrics, Sorona® polymer improves

the softness and resilience of nonwovens such as medical garments, monofilaments
and brushes.
 DUPONT™ Sorona® polymer

2. Stretch with recovery (2-3x greater than nylon) Market availability Industry leadership
Both flat and textured yarns made from Sorona® may be made Fiber made with Sorona® is available through a global network of
into fabrics with advanced levels of comfort fit. licensed fiber producers and mills. A variety of additives,
Research shows that fully drawn flat yarn made with Sorona® modifiers and lusters are also offered, and specialty differentiated
recovers 100% from approximately 120% strain. Even at higher polymers are being developed for unique market opportunities.
strain levels, fibers made with Sorona® recover completely,
DuPont, the industry leader in meeting the requirements of fiber
returning to their initial form.
and fabric producers worldwide, has extensive experience
For textured yarns, fibers made with Sorona® offer up to 145% working with Sorona® and many other polymers. Its expertise
stretch with 100% recovery. Allowing for the hysteresis effect encompasses the entire chain of processes, from raw materials to
normally present in textured yarn, fiber made with Sorona® finished garments. DuPont starts with the basic chemical building
supports a more substantial recovery than other hard yarns do. In blocks of the fiber-grade intermediates that comprise polymers,
addition, Sorona® enables textured yarns to provide greater bulk then continues through the continuous polymerization processing
and cover than nylon, using the same amount of fiber. that ensures polymer purity and consistency and finally the
innovation is transferred to all down-stream processes involved in
3. Easy dyeability at the boiling point with no carriers creating fibers, fabrics and finished garments. This is a range of
Using standard available dyes, fibers made with Sorona® can be competencies unmatched by any polymer resource in the world.
dyed at a lower temperature than polyester, without requiring
pressure or chemical carriers. The Sorona® polymer molecule What’s Next
enables the crystalline structure of the fiber to begin accepting DuPont™ Sorona® polymer is made from two monomers or
the dye pigment below the boiling point, at approximately 85° C. ingredients, one of which is 1,3 propanediol or PDO. DuPont
Full depth of color is achieved at the boiling point, with pioneered a way to produce the 1,3 propanediol from renewable
outstanding washfastness. resources, namely corn sugar. In 2004, DuPont formed a joint
venture with Tate & Lyle, a major corn-based products company
To create patterned fabrics with multiple colors, fibers made
with expertise in fermentation processes, to produce Bio-PDO™.
with Sorona® can be blended with other fibers prior to dyeing,
resulting in differently patterned knit or woven fabrics. In blended The Bio-PDO™ plant, in Loudon, TN is the world’s largest aerobic
fabrics, Sorona® contributes a unique combination of benefits. fermentation plant and is capable of producing 100 million pounds
of Bio-PDO™ annually. On a pound for pound basis, production of
4. Resiliency similar to nylon Bio-PDO™ consumes about 40% less energy than production of
For use in fabrics such as fleece and velour, fibers made with its petroleum-based counterpart. The Bio-PDO™ will be used in
Sorona® provide a high level of resilience. The crystalline structure the manufacturing of Sorona® in early 2007.
of the Sorona® polymer molecule enables the fiber to retain its
The advantages of transitioning to a renewable resource based
original memory and bulk, ensuring that the fabric wears
process for the production of PDO are many and include a smaller
exceptionally well.
environmental footprint, lower manufacturing costs, less energy
used, less capital and a more reliable supply of feedstocks.
5. Heatsetability
For easy-care fabrics, fibers made with Sorona® are heatsettable DuPont continues to innovate to bring quality, high performance
and, if the process is completed correctly, heatsetting does not products to market in a way that reduces its environmental
diminish the stretch with recovery capacity of Sorona®. Most footprint.
important, fabrics made with Sorona® are heatset at lower
temperatures than polyester, providing manufacturers with a new
option for blending Sorona® fibers with spandex to create www.sorona.dupont.com 866-4-SORONA (866-476-7662)
garments with high-power stretch capabilities. DuPont™ Sorona® • Wilmington, DE 19880-0728

Note: We believe this information is the best currently available on the subject. It is offered as a possible helpful suggestion in experimentation you may care to undertake along these lines. It is subject to revision as additional knowledge and experience
are gained. DuPont makes no guarantee of results and assumes no obligation or liability whatsoever in connection with this information. This publication is not license to operate under, or intended to suggest infringement of, any existing patents.
Copyright © 2006 DuPont. The DuPont Oval logo, DuPont™, The miracles of science™ and Sorona® are trademarks or registered trademarks of E. I. du Pont de Nemours and Company. All rights reserved.
K-15626 Rev. 04/06