The Honduran textile industry hosted a reception in San Pedro Sula, Honduras, to celebrate the
passage of CBI parity legislation, according to Peter Hegarty, president, American Textile Export
Co.The event was organized by The Honduran Counsel for Private Companies, The Honduran Association
of Maquiladores, The Chamber of Commerce and industries of Cortes, and The Free Zone Association of
Honduras.”The Trade and Development Act of 2000 will certainly enhance trade between the United
States and Caribbean Basin countries and, in our view, provide a much-needed boost to domestic yarn
spinners, among others,” said Bud Willis, president, Tuscarora Yarns, Oakboro, N.C. “To best take
advantage of the opportunities this legislation offers, American companies need to quickly get to
know their potential Caribbean Basin partners and any unique requirements they may have.”

October 2000

Southern Weaving Co., Greenville, S.C., has been recapitalized for growth and acquisitions by Blue
Point Capital Partners, Charlotte, N.C.”We are excited about the opportunities that this business
partnership creates,” said Rod L. Grandy, CEO, Southern Weaving. “By recapitalizing, we are now
able to facilitate continued strategic growth through acquisitions. With Blue Point Capital
Partners, we have found a partner that uniquely understands our manufacturing environment and adds
considerable strategic insight to our plan to broaden the business via acquisitions.”

October 2000

DB Investor, the Industrial and Private Equity Holding Arm of Deutsche Bank, is acquiring
Germany-based Trevira GmbH.”Under its new owner, DB Investor, Trevira will be launching, with even
greater aggression, a number of innovative products onto the market, It will further extend the
Trevira brand and, in addition, tackle markets outside Europe with increased vigor,” said Ulrich
Huwe, CEO, Trevira.

October 2000

Cationic Pretreatments Of Cotton
Fiber treatment before dyeing reduces environmental pollutants, increases dye
affinity. Despite the widespread acceptance and demand for cotton apparel, there are
still some significant problems remaining with the wet processing of cotton fabrics.Considerable
amounts of harsh chemicals and hot water are required to properly desize, scour and bleach cotton.
Once the fabrics have been adequately prepared, dyeing processes for cotton suffer from some
serious environmental difficulties. The most convenient dye classes for cellulose direct dyes and
fiber reactive dyes both require significant amounts of electrolytes to achieve even reasonable
exhaustion rates. These water-soluble anionic dye molecules do not have strong enough affinities
for the fiber without the presence of up to 100 grams per liter (g/L) of either sodium chloride or
sodium sulfate in the dye bath. Once exhausted to the fiber, direct dyes have only fair
washfastness with after-treatments. Since fiber reactive dyes will react with water as well as with
the cotton fiber, as much as 50 percent of the dye is hydrolyzed and must be scoured from the
fabric in order to reach acceptable fastness levels.A fiber treatment applied before dyeing that
would leave the cotton fibers with cationic charges would seem to be a possible solution to both of
these problems. D. M Lewis and X. Lei have reviewed this approach1, and recent work has used
cationic pretreatments to achieve union dyeings of cotton/wool blends2,3.Until the mid-1980s, use
of pigments to color textiles had been generally limited to pad applications because of the
inability of pigments to exhaust to fibers. Since that time, a number of researchers have looked at
cationic pretreatments of fabric prior to exhausting pigments4-6, and the process of exhausting
pigments to garments has become important commercially7,8. 

Figure 1. Diagram of process by which cationic polymers forma layer of cationic charges when
applied to fiber surfaces.

Figure 2. Diagram of process by which reactants modifythe fiber by forming covalent bonds
with the cellulosic fiber. Chemistry Of Cationic PretreatmentsThere are two fundamentally
different types of cationic pre-treatments in use. The first type are cationic polymers that form a
layer of cationic charges when applied to fiber surfaces (See Figure 1).The second category of
cationic pretreatments involves reactants that modify the fiber by forming covalent bonds with the
cellulosic fiber (See Figure 2). The presence of cationic charges on or in the fiber causes anionic
materials such as direct and fiber reactive dyes to be strongly attracted to the fiber and to be
held much more tightly than without the cationic charges.Many types of polymeric cationic
pretreatments have been developed. Some of the chemistries employed include polyacrylates4,
polyimidazoles, polyamideepichlorohydrin resins1, and polyamino condensates2. Their actual
compositions for the most part are proprietary.Reactant cationic pretreatments are usually small
molecules that can form covalent bonds with cellulose. Two examples of chemicals that have been
studied are choline chloride4 and N-(3-chloro-2-hydroxypropyl) trimethyl-ammonium chloride9. 

Figure 3. Diagram of modified fiber formed when choline chloride is reactedwith DMDHEU and
catalyst in the presence of cotton. 

Figure 4. Diagram of cationically modified cotton when
N-(3-chloro-2-hydroxypropyl)trimethylammonium chloride is reacted with cellulose under alkaline
conditions. 

Figure 5. Diagram of end result when cationic pretreated cotton is pigment
dyed. Application Of Cationic PretreatmentsCationic pretreatments have been applied to
textiles in two general ways: padding and exhaustion. Polymeric pretreatments have been
incorporated into durable press formulations2,4 applied to fabrics prior to dyeing. Garments can be
treated with cationic polymers with an exhaustion procedure carried out just prior to dyeing5-8.
The efficiency of this exhaustion treatment is directly affected by process parameters such as pH,
temperature, time and agitation level.The goal of exhausting cationic polymers is to provide a
uniform layer of polymer on the fabric surface. Excessive buildup of polymer on the interior
machinery surfaces can occur if the exhaustion process is not carefully controlled. The surface of
the fabric should be clean and free from contaminants such as wax and size in order to assure a
proper pretreatment.Reactant pretreatments have been successfully applied to fabrics by pad
applications3,4,9,10. At present, the most economical reactant pre-treatments are small
water-soluble molecules that do not readily exhaust to cotton fabric. As a result, exhaustion
techniques have not been utilized as extensively as padding procedures. Recent patents, however,
demonstrate continued interest in application of cationic reactants to garments11,12.Cationic
reactants have been attached to cellulose by several mechanisms. For example, choline chloride has
been reacted with DMDHEU and catalyst in the presence of cotton to give a modified fiber according
to the scheme shown in Figure 34.N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride has been
reacted with cellulose under alkaline conditions to yield cationically modified cotton directly10
(See Figure 4).In all cases, uniform application of the cationic reactant to the fabric prior to
chemical reaction with the fiber is essential. Unlevel dyeings are the inevitable results of uneven
applications of cationic pretreatments. Pigment Dyeing Of Cationic Pretreated CottonExhaust
dyeing of cationic pre-treated cotton with pigments is a three-step process:application of
pretreatment (exhaust or pad);exhaustion of pigment; andexhaustion of a binder.Pigments intended
for exhaust application to cationically pretreated fabrics are designed to be anionic or nonionic
when dispersed in water. The exhaustion of these pigments is controlled not only by the pigment
particles charge, but also by the pH and temperature of the dye bath, the length of exhaustion
cycle and the agitation level in the dyeing machine.Polymeric binders are used to increase the
durability (washfastness and crocking) of the pigment-dyed fabric. These binders are usually
cationic in nature and are exhausted to the fabric by controlling treatment bath pH and
temperature.The end result of this process is a multi-layered structure that can be represented by
the diagram shown in Figure 5.The colorfastness of pigment-dyed garments is strongly dependent on
the interactions among pretreatment, pigment and binder. Considerable development work is often
necessary to arrive at a commercially acceptable product.A typical pigment garment-dyeing procedure
is given in Table I. The procedure can vary depending on the machinery used and the specific
pretreatment, pigments and binder chosen. Chemical suppliers will provide the actual
details.  Dyeing Of Cationic Pretreated Cotton With Anionic DyesAdding cationic charges
to cotton fiber greatly increases the exhaustion rate and exhaustion level of anionic dyes.
However, this increased affinity can lead to unlevel dyeings unless the dyeing process is carefully
controlled. The uniformity of the dye strike is influenced by the pH and temperature of the dye
bath and the rate of addition of the dyes. Salt is not required for complete exhaustion, and much
higher color yields (approxi-mately 25 percent higher) are seen. Afterscouring of reactive dyes is
usually not necessary, and direct dyes do not require an aftertreatment to achieve acceptable
washfastness. A typical procedure for dyeing cationic pretreated cotton with anionic dyes is
outlined in Table II. SummaryPolymeric cationic pretreatments for cotton offer several
advantages for the garment wet-process industry. Pigments can be exhausted to garments, allowing
styling options not easily obtained by other processes. Existing equipment can be utilized for
these pretreatments because the polymers exhaust to the fabric surface. Disadvantages to be
considered are the fact that the procedure is a complex multi-step process, and often the
lightfastness of anionic dyes is adversely affected by the pretreatment.Reactant cationic
pretreatments for cotton also offer several advantages for the garment wet processor. Fiber
reactive dyes can be used without salt, and the amount of unfixed dyes is greatly reduced.
Significant energy savings can be realized by the reduction of the amount of hot water needed for
the process. Currently, however, the most efficient way of applying reactant cationic
pre-treatments to garments is a fabric application in which pretreated sewing threads are used with
pretreated fabrics during garment manufacture. In addition, the dye procedure must be carefully
controlled to ensure level dyeings.As the reduction of pollutants in textile wastewater grows in
importance, interest in the use of cationic pretreatments for cotton can be expected to grow
also. References1Lewis, D. M. and X. Lei, Textile Chemist and Colorist, Vol. 21, No. 10,
October 1989, 23.2Cardamone, J. M., G. Bao, W. M. Marmer, R. L. Dudley and J. Bulan-Brady, Textile
Chemist and Colorist, Vol. 28, No. 12, December 1996, 19.3Cardamone, J. M., W. M. Marmer, E. J.
Blanchard, A. H. Lambert and J. Bulan-Brady, Textile Chemist and Colorist, Vol. 28, No. 11,
November 1996, 19.4Harper, R. J., Jr., Journal of Coated Fabrics, Vol. 18, No. 4, April 1989,
234.5Angliss, I. and R. Blair, Australasian Textiles, Vol. 10, No. 4, July/August 1990, 56.6Chong,
C. L., S. Q. Li and K. W. Yeung, American Dyestuff Reporter, Vol. 81, No. 5, May 1992, 17.7AATCC
Garment Wet Processing Technical Manual, 1994, 106.8Cotton Dyeing and Finishing: A Technical Guide,
Cotton Incorporated, 1996, 74.9Rupin, M., Textile Chemist and Colorist, Vol. 8, No. 9, September
1976, 54.10Patton, R. T., J. D. Kitchens and D. M. Hall, U. S. Patent 5,006,125 (1991).11Hall, D.
M., T. M. Leonard, C. D. Cofield and H. W. Barrow, U.S. Patent 5,330,541 (1994).12Hauser, P. J. and
S. G. Helfrich, U.S. Patent 5,667,533 (1997).
Editor’s Note: Peter Hauser, Ph.D., is an associate professor of textile chemistry at North
Carolina State University College of Textiles, Raleigh, N.C. His research focuses on
high-performance chemical finishes for enhanced value textiles, indigo dyeing and denim garment wet
processing, new textile processes to reduce costs and energy use and pollution associated with wet
processing. Dr. Hauser holds several patents. He can be reached by telephone at (919) 513-1899 or
by e-mail at peter_hauser@ncsu.edu.The original text of this article was presented at the Emerging
Technologies and Trends in Garment Wet Processing Symposium, New Orleans.

October 2000

More than 200 million pounds of post-consumer nylon 6 carpet waste will be kept out of U.S.
landfills each year because of the efforts of environmentally conscious Evergreen Nylon Recycling
LLC (ENR), Augusta, Ga.Honeywell International (formerly AlliedSignal Inc. Performance Polymers),
Colonial Heights, Va., and DSM Chemicals North America Inc. (DCNA), Augusta, Ga., are the joint
venture partners of ENR. The recycling plant, which celebrated its grand opening in November 1999,
is the first economical, large-scale recycling operation for the recovery of first-quality
caprolactam from waste carpet and nylon scrap, according to Richard Lawson, manager, total quality
and training, DCNA. The operation allows nylon to be recycled repeatedly in a truly closed loop.The
recycled nylon can be used in any nylon application, including new carpet, because the process
produces material that is exactly the same as that made from new raw materials. Even the by-product
fibers from the carpet backing will be reclaimed and marketed for use in cement and other products.
Lawson noted the $85 million facility would keep more than 200 million pounds of post-consumer
nylon 6 carpet waste out of U.S. landfills each year. “Carpet represents about 2 percent of total
waste in U.S. landfills, and this business enterprise will reclaim nearly 20 percent of all
discarded nylon 6 carpet,” he said.The demand for recycled content in products continues to rise in
response to environmental, legislative and consumer pressure. A number of vehicle manufacturers are
now reacting by specifying percentages of recycled content in their components. Dave Mezzanotte,
general manager, ENR, and vice president and general manager, Honeywell, said, “This venture allows
us to do something that has never been done before we can make a nylon product live forever. Not
only do our products offer significant environmental benefits, but they are made with the same
quality as virgin nylon products, so you would never know they were recycled.”Lawson added,
“Quality is very important to all products, including nylon. In 1992, DCNA achieved ISO 9001
certification. Through its well- developed quality system, and the extensive in-depth training
given employees, ENRs product quality is second to none.” Nylon 6 Polymer FacilityLawson
explained that, through a polymerization process, the plant converts monomer (caprolactam) to nylon
6 polymer. The monomer feedstock is both virgin monomer from the DCNA plant and recycled monomer
from the ENR plant.The facility consists of two parallel polymer trains and shared utilities. One
polymer line is currently the largest of its kind, producing polymer for carpet fiber applications.
Most of the output of this line is dedicated to one of the largest carpet manufacturers in the
world. The second, smaller line produces polymer for engineering plastic applications, with most of
its output dedicated to DSM Engineering Plastics, a DCNA affiliate company.”This facility is
state-of-the-art with smart instrumentation, computer-based DCS [digital control system] control,
and virtually 100-percent conversion of monomer to polymer,” Lawson said. “Final product is shipped
bulk truck, bulk rail and Gaylord packages.” Carpet CollectionSeveral years ago AlliedSignal
and DCNA launched a pilot facility to recycle carpet. By the end of 1997, the experiment in carpet
recycling was considered a success. The next step was to commercialize the experiment and develop a
facility that could recycle more than 1 billion pounds of post-consumer carpet per year.”In
preparation for this unprecedented commercialization, we have been promoting that industry should
collect carpet,” Lawson said. “This industry of recycling is still in its infancy, but we have
learned a great deal about carpet collection over the past several years and are optimistic that it
will continue to blossom.” Carpet collection is already underway in 75 metropolitan areas
throughout the U.S. In fact, ENR has already collected 70 million pounds of carpet for production.
Carpet retailers can save tens of thousands of dollars each year in landfill fees and other
disposal costs by being part of the collection network, Lawson said.By integrating information and
resources, innovative methods often emerge, as was the case with this joint venture. DCNA In
BriefDCNA is a business unit of the Netherlands-based DSM Fiber Intermediates Business Group. This
integrated international group of companies is active worldwide in chemicals, biotechnological
products and plastic materials. The group has annual sales exceeding $7 billion and employs about
23,000 people at more than 200 sites in Europe, North and South America, Asia, Africa and
Australia.DCNA, originally a joint venture between DSM BV and Pittsburgh-based PPG Industries, was
founded in 1962. Their first venture was a nitrogen fertilizer complex. In 1964, Nipro, Inc. (the
predecessor of DCNA) was organized to manufacture caprolactam, the monomer of nylon 6 used in nylon
fiber production. Subsequent expan-sions of DCNA in 1972 and 1976 made it the largest independent
market supplier of caprolactam in the United States. DSM bought out PPGs interest in the venture in
1973. Construction on the ENR plant in Augusta began in the fall of 1998. Honeywell
(AlliedSignal) In BriefPerformance Polymers is a strategic business unit of Honeywell
Inter-national. Honeywell merged in 1999 with AlliedSignal Inc., an advanced technology and
manufacturing company serving customers worldwide with aerospace products and services, automotive
products, chemicals, fibers, plastics and advanced materials. AlliedSignal was one of the 30 stocks
that make up the Dow Jones Industrial Average and is also a component of the StandardandPoors 500
index. The company employs 70,400 people in some 40 countries.The merged company retained the
Honeywell name and trades under the ticker symbol HON on the New York Stock Exchange. Honeywell is
now part of the Dow Jones Industrial Average, taking the place of AlliedSignal. This merger has
created one of the nations largest companies. In 1999, Honeywell was listed as a Fortune 50
company, with sales of about $24 billion. Honeywell operates in 96 countries and has more than
120,000 employees. The combined market capitalization of Honeywell International exceeds $45
billion. Lawson said the primary reason for the merger was to take advantage of synergies in the
aerospace business.Both Honeywell and AlliedSignal manufactured components used in commercial
aircraft. Their merger is expected to save as much as $750 million by 2002. Some of this savings
will be realized through elimination of redundant jobs, but a large part is expected to come from
an acceleration of AlliedSignals 6 Sigma quality program. The new Honeywell Inter-national will
have businesses in aerospace, control technology, auto-motive, power generation, specialty
chemicals, fibers, plastics, electronics, and advanced materials.ENR is part of Honeywells fibers
and plastics business that makes nylon 6 resin for use in fiber products such as carpet and
industrial textiles, as well as engineering resins that are typically used in automotive
applications. Patented TechnologyNylon fibers can be recycled time and time again back to
their base material without any loss of properties. This post-consumer system is the most complete
form of recycling available, according to Lawson. The recycling process does not produce any waste.
Even the non-nylon 6 materials and the dirt present in used carpet (which, together, form 55
percent of carpet waste), are economically reused as a co-product.The ENR plant uses a jointly
developed, patented technology that depolymerizes nylon 6 into capro-lactam. Nylon 6 is used in
such applications as residential and com-mercial carpet, engineering plastics, automotive parts,
sporting goods, films and packaging. The facility will produce more than 100 million pounds of
caprolactam each year with the same performance and aesthetic qualities as virgin
caprolactam.Caprolactam is the primary raw material used in the production of nylon 6. At DCNAs
plant, it is stored in liquid form in tanks heated to a temperature of 170°F. Molten caprolactam is
shipped to domestic customers who convert it to nylon 6 for end-uses including carpet, tire cord,
monofilament (trimmer/edger line and fishing line) and engineered plastics. DCNA also cools the
molten capro-lactam into a solid state known as flake caprolactam. The flake is then packaged for
export sales primarily for textile applications (apparel and hosiery).The ENR facility is also a
model of energy efficiency, saving 700,000 barrels of oil and 4.4 trillion British Thermal Units
(BTUs) per year compared to conventional caprolactam production. Lawson noted this is enough energy
to heat 100,000 medium-sized homes for a year. Recycling AdvantagesThe key drivers for nylon
6-to-caprolactam recycling are as follows: Caprolactam can be produced economically with quality
equal to virgin material.Material life is extended, saving money in the business chain.The process
is environmentally sound from every aspect.Demand for materials and components with a recycled
content is growing.Because ENR can accept only nylon 6 waste, it became apparent from the start
there had to be a way to sort nylon 6 carpet from forms such as nylon 66 and polyester.Experienced
operators are critical to maintaining product quality. “Therefore, it is extremely important that
workers be trained properly in the use of sorting equipment and other markings, which can be used
to identify carpets,” Lawson said.  Indentification CodesIdentification codes are printed
either directly on the back of the carpet as a string of letters or on an attached bar-code label.
This label is called a carpet component identification code (CCIC), which is a 7-digit alpha code
developed by the CarpetandRug Institute (CRI), Dalton, Ga., to identify the construction of a
carpet. This code has been used since 1996. Because the average life of a carpet is between eight
and 12 years, the only carpet likely to have the code on it today are remnants and installation
scraps.The most important digit in the code is the first letter. An A in this position indicates a
nylon 6 carpet, which is the type ENR recycles. B or C indicates a nylon 66 carpet. The second or
third code position identifies the type of primary and secondary backing used. An X in any position
indicates the manufacturer has not identified that part of the code. Melt Point
IndentificationThe simplest and least expensive type of sorting equipment currently identifies
carpet based on the melt point of its face fiber. A simple device can be made to identify carpet
based on the melt point. A device with two or three heated probes can be used to “brand” the
carpet.Such a device is commercially available from Cooper Tools under its brand name, Fiber-Rite.
The major drawback is its inability to distinguish between polyester and nylon 66. However, it
provides an inexpensive method that can be used to presort carpet. It can also be used to identify
carpets closer to their source, reducing the ultimate handling and disposal fees. Near
Infrared Sorting (NIR)The most accurate, reliable and versatile technique for identifying carpet is
based on near infrared (NIR) spectroscopy, according to Lawson. The carpet is illuminated using a
standard light source, and the reflected light is measured. Different materials absorb light
differently in various areas of the spectrum. By measuring and analyzing the reflected light, it is
possible to identify the face fiber type.CarPID, an NIR technology developed by DCNA and Honeywell,
is used as a portable instrument for the fast and safe identification of carpets according to their
face fiber type. The fiber materials nylon 6 (N6), nylon 66 (N66), polyester (PET), polypropylene
(PP) and wool (W) are distinguished. As with all commercially available NIR devices for sorting
carpet, a correct identification of blends is not guaranteed. Blends are normally classified and
displayed according to their major component. Sorting StandardsThere are known standards for
sorting that should be used to ensure that sorting equipment is functioning properly. “If there is
a question about the identity of the carpet, discard it,” Lawson said. Questionable carpets, he
suggested, could be blends. The dye-ability differences of face fibers are used to create styling
effects. For example, a three-color carpet with blue, gray and black, could contain nylon 6 as the
black fiber, nylon 66 as the gray fiber and polypropylene as the blue fiber.Operators can learn to
look for blends and pull the carpet when there is a question during testing. Lawson also said the
carpet should be tested on a clean, dry area. Impurities such as paint and moisture can cause
sorting errors.Another important area is cutting the carpet to be recycled. If using vertical
baling equipment, Lawson said it is best to cut the carpet to the width of the baler and make tight
rolls to place in the baler. “A best practice is to mark the width of the baler on the floor
directly in front of the baler,” he said. “Then the carpet can be spread out on the floor in front
of the baler and cut to the proper width with a rotary electric carpet cutter.”Lawson explained
there are two general types of balers used in the recycling industry: vertical down-stroke and
horizontal. The baler type is based on the orientation of the hydraulic ram used to compress the
material. A vertical baler has a vertical ram, and a horizontal baler has a horizontal
ram.Horizontal balers are generally larger and more expensive than vertical balers. Their advantage
is that they can usually produce larger, denser bales. Baling can also be automated to some extent
using equipment to tie the bale and compress it when the loading chamber is full.Vertical balers
are smaller, less automated and less expensive. They come in two classes: light-duty and
heavy-duty. Most pad recyclers use the light-duty balers for polyurethane foam. However, Lawson
recommended that, for post-consumer carpet, the recycler use a heavy-duty baler because it has a
heavier construction and a higher-horsepower hydraulic ram. Post-Industrial WasteIn addition
to carpet collection, post-industrial (P-I) nylon waste is also being collected throughout the
United States. Examples of P-I waste include waste from casting operations as well as yarn waste
from carpet manufacturers. P-I waste typically has a higher nylon 6 content than discarded carpet
and is valuable feedstock for ENR. As with carpet waste, ENR will divert a portion of P-I waste
from landfills and turn the waste into a product.ENRs system will allow Honeywell to produce its
Infinity, Forever Renewable Nylon, which is recycled and renewable in a truly closed-loop process.
All applications of nylon 6 are acceptable for Infinity nylon, including producing high-performance
carpet fibers with all the design and perform-ance characteristics of virgin nylon.DCNA will market
its share of the recycled caprolactam from the ENR facility under the trade name ReCap, which will
be available to the merchant caprolactam market. ReCap will also be marketed through DCNAs
downstream nylon polymer products, including carpet spinning chips and DSMs Akulon® Renew
engineering plastic resins.Lawson said ENR is working hard to ensure environmental excellence. “We
have made a strong commitment to this project, both emotionally and financially. Plus, we are
constantly searching for ways to make recycling easier and more affordable. We expect to continue
to be a leader in this industry.” 

October 2000