flexibility and efficiency are the most notable benefits that synthetic
fibers can deliver to nonwovens. These benefits allow synthetic fibers
to be applied in nearly every market for nonwovens, including hygiene,
medical, filtration, automotives, wipes, artificial leather and bedding.
Because they can be engineered, synthetic fibers also work well in
a variety of nonwovens technologies such as airlaid, carded, thermal
bonded, needlepunched and spunlaced. Furthermore, synthetic fibers
can be easily dyed and chemically finished.
Polyester has remained one of the most popular synthetic fibers in
nonwovens, because of its versatility in a wide range of end uses.
Most recently, polyester has found a place in the hygiene market,
especially in baby diapers, feminine hygiene products and adult incontinence
items and wipes. Polyester in diaper acquisition/distribution
layers provides increased moisture-management properties and strength,
explained Robert Usher, business director of Wellman Incorporated,
Shrewsbury, NJ. Polyester additionally will prevent gel blockage
and fluff pulp from collapsing in these products. It helps move fluid
to absorbent layers in the diapers that contain superabsorbents. In
wipes, polyester fiber provides increased fiber strength and stability.
Because of polyesters overall functionality and performance,
manufacturers are steering toward using it in the hygiene market.
Although polyester is more expensive than wood pulp and superabsorbent
fibers, its functionality is important to the overall product. Natural-based
fibers, such as wood pulp, serve more as an inexpensive filler and
absorbent fiber, while polyester is more technical.
Polyester staple fiber is one of the most rapidly growing fibers
due to its cost effectiveness, turnkey technology and ease of processability
and care, said Horst Lehmbach, business segment manager of nonwovens
at DuPont Sabanci Polyester GmbH (Dupont SA), Hamm, Germany. Almost
all end uses can use polyester because it does not have limitations.
Polyester fibers can be produced with different deniers, cut lengths
and cross sections.
Additionally, polyester can have a range of luster options, such as
bright or semi-dull. This can help improve the stress-strain behavior
of nonwovens, particularly in thermal bonded and spunlaced nonwovens,
according to Suthida Archadech, key account manager of Bangkok-based
polyester fiber supplier, Tuntex Thailand, Polyester fibers
offer the opposite of what a cotton fiber can offer because they have
higher elongation properties, he explained. Furthermore,
these fibers provide permanent hydrophilic properties, which is ideal
for hygiene disposable products.
In addition to polyester, other synthetic fiber types making strides
in nonwovens include polyolefin and polypropylene. These fibers offer
the much sought-after balance of high performance and low cost, making
them attractive to many markets.
Polypropylene fibers will continue to grow in different applications
and markets, such as filtration, as they become more advanced, more
refined and more application-focused, opined Erik Gammelgaard,
marketing manager at FiberVisions, Varde, Denmark.
AG manufactures cellulose staple fibers for nonwovens in the
hygiene, medical, cosmetic,
household and automotives markets.
Wanted: Specialty Markets
Synthetic fibers are already well established in several end use
markets for nonwovens, such as filtration, hygiene and artificial
leather. Polyester fibers are also establishing a niche for themselves
in the home furnishings and do-it-yourself (DIY) markets such as
wallpaper. Using polyester staple fibers in nonwoven wallpaper can
offer increased strength. Anyone dealing with wallpaper professionally
knows nonwovens are considered to be a synonym for wallpaper with
attributes, including strength and dimensional stability,
Mr. Lehmbach explained. In comparison to traditional wallpaper,
nonwoven products are produced on modified papermaking or specialty
equipment for wetlaid fabrics. This is capable of processing longer,
stronger fibers, compared to pure cellulose pulp.
DuPonts Dacron polyester fiber is currently used as a reinforcement
material in wallpaper with more advantages during installation.
These include no paste dwell time, immediate adhesion and dimensional
stability when wet. Additionally, the stability and opacity of polyester
nonwovens in wallpaper can help disguise cracks and seams.
During the past 18 months, the demand for polypropylene non-foaming
fibers has increased significantly in water filtration media,
said Geoff Rostron, sales manager of Drake Extrusion, Bradford,
West Yorkshire, U.K. These non-foaming fibers are formed by
using a dref spinning system, where the fibers are spun into yarns
and then wound into a cartridge. Thousands of tons of our polypropylene
are now being applied in water filtration media.
The rise of these more specific applications has synthetic fiber
manufacturers using newer, more innovative technologies to improve
the final product. Experimenting with fiber selection and newer
converting and bonding techniques has become an essential part of
the production process.
fibers are gaining ground in diapers, where they aid in transporting
Manufacturers have been relying on bicomponent and multicomponent
technologies to expand synthetic fibers presence in nonwovens
markets. As end product demands become more stringent, fiber suppliers
must also do their part to choose the best fiber combinations for
these newer technologies.
As technology continues to improve, fiber blends are becoming
more commonplace, explained Paul Latten, nonwovens and industrial
staple business director of KoSa, Houston, TX. KoSa offers
pre-blended fibers that give manufacturers enhanced synergistic
properties while reducing the cost, time and effects of blending
internally. Our polyester fibers have achieved success in blends
with glass and carbon-based fibers in a range of markets such as
geotextiles, construction, industrial and automotives.
Bicomponent fibers allow nonwoven manufacturers to have the best
of both worlds. For example, using a bicomponent fiber can
allow customers to get an environmentally friendly binder solution
by combining the benefits of a polyethylene and a polypropylene
reinforcing fiber, in one product. This eliminates the need for
latex spray bonding.
Bicomponent fibers are engineered to deliver enhanced adhesion
using various bonding temperatures, with a range of other fibers,
including wood pulp, rayon, polyolefin, glass, cotton, nylon and
wool, said KoSas Mr. Latten. This yields increased
strength, resiliency, improved absorbency and flexible design options
such as embossing.
Aware of the impact that fiber selection has on a nonwoven web,
manufacturers are experimenting with different ways to engineer
the fiber. For example in a spunlaced web for hygiene applications,
the fiber must be finished so that it can provide permanent hydrophilic
properties. Likewise, a low-melt polypropylene fiber will often
be selected if the web will be thermal bonded, as these products
require both a higher and a lower melting fiber for more uniform
bonding. A more uniformly bonded product allows bulk.
Despite the increasing importance of fiber selection and technology,
cost dictates new trends in the synthetic fiber market. With the
prices for wood pulp, superabsorbent fibers and cellulose less expensive
than other fibers, manufacturers are discovering that these fibers,
depending on the bonding technology used, can produce the same qualities
as more expensive fibers. One such fiber is polyacrylate, which
is found in superabsorbents (SAP) powders. When applied in hygiene
applications, these fibers provide more liquid absorption and thinness.
For Technical Absorbents, Grimsby, U.K., polyacrylate is the only
fiber in its Oasis superabsorbents, which are used in feminine hygiene
products and food trays.
made of polyester fibers will continue to grow in the automotive
market because of their ability to be easily molded.
The demand in hygiene products is for less bulk and more
thinness, explained David Hill, business development manager
of Technical Absorbents. Because of this, fibers such as wood
pulp and polyacrylate will gain ground as the fiber of choice for
nonwovens, especially in airlaid products. As airlaid technology
continues to grow in the baby diaper and feminine hygiene markets,
traditional fibers will be considered too costly for airlaid applications.
However, by using cellulose or fluff pulp fibers with the airlaid
process the same results are achieved as using rayon with a carding
technology, which are more expensive. In order to have higher profit
margins in the synthetic fiber market, it is important to choose
fibers that will match the converting and bonding technologies.
Manufacturers are also switching to cellulose and wood pulp fibers
within the wipes market. As this market continues to boom worldwide,
several areas within this market might face the threat of becoming
a commodity. Manufacturers are responding to these possibilities
by switching to low-cost fibers, such as cellulose, in place of
more expensive carded fibers. The traditional ways that wipes
have been made, which have included carding, are being attacked
right now by airlaid and spunlace technologies, Mr. Hill said.
The only setback for airlaid is the cost of the equipment.
However, it will only be a matter of time until manufacturers will
be able to buy airlaid machinery to make core material for hygiene
In the meantime, cellulose and fluff pulp will continue to penetrate
the wipes market because of their low cost and high absorbency.
These attributes will allow these materials to expand more into
end products. Tencel, Flemington, NJ, manufactures Lyocell fiber,
which is a man-made fiber from a natural cellulose polymer, for
wipes and other key markets. Lyocell is ideal for wipes because
of its purity, high dry and wet strength, stability and absorbency,
according to executives.
uses polyacrylate fibers, which are derived from superabsorbents,
to manufacture its Oasis fiber.
Notable successes to date for Lyocell have been in spunlaced,
wetlaid and needlepunched fabrics for wipes, filtration and artificial
leather substrates, said Nick Hrinko, nonwovens business director
of Tencel. Cellulosic fibers will increase marketshare in
areas where their key attributes are critical to the final product.
For cellulose to continue gaining marketshare in the wipes and hygiene
markets, manufacturers are using it in combination with other fibers
so the nonwoven web can hold up to the higher line speeds and other
machinery advancements coming onstream.
On one hand, cellulose will need to cope with increasing
line speeds, and on the other, it will need to supply specialty
fibers with new properties, explained Heinrich Jakob, marketing
and sales director for nonwovens at Lenzing, Austria-based Lenzing
AG. In response to this, cellulose is being combined with polyester
for spunlaced wet wipes. This creates material that is soft yet
strong enough for higher line speeds and bonding processes.
fibers, derived from wood
pulp, are replacing cotton in hygiene applications.
As new machinery and technological advancements continue to grow
in the nonwovens industry, nonwovens manufacturers are also examining
new geographical areas for possible expansion. Asias large
population has attracted nonwovens manufacturers to this area. As
this move continues to escalate, it will spur additional competition
among fiber suppliers in North America and Europe, leading to a
tougher fight to gain marketshare.
Manufacturers have to remember that the fiber industry is
global, stressed FiberVisions Mr. Gammelgaard. China
and India especially have a huge capacity of man-made fibers. I
think other fiber manufacturers will be facing tough competition
from the Asia-Pacific region. This will force manufacturers to find
new ways of competing including speeding up product development,
working more closely with customers and forming alliances throughout
the value chain.