chapter 7 Flashcards
what is a Nonwoven Fabrics
-Textile materials bonded
together by entangling fiber or filaments
mechanically, thermally or chemically.
-made by weaving or knitting and
do not require converting the fibers to yarn.
DISPOSABLE
-Is a good one for one use
-not expensive
-mainly used for cleaning products
- The major fiber used for disposable
nonwovens is rayon.
DURABLE
-not intended to be
thrown away after a single use.
-Durable nonwovens are often used as a small but
important component of a total garment or
industrial application.
- Durable nonwovens are used for apparel
interlining, carpet and upholstery fabrics
(padding and backing), automotive headliners
and upholstery, insulation, roofing products,
3 Methods of Manufacturing
Nonwovens
- Dry laid system
- Wet laid system
- Polymer laid
Dry laid system
The material structure is formed by manipulating the fibers while in a dry state. This is the most used system worldwide.
Wet laid system
The material structure is formed by having the fibers manipulated while in a wet state. (similar to paper making)
Polymer laid
The material structure is formed by blowing thermoplastic fibers onto a collection surface as the fibers are being extruded.
Needle-punched nonwovens
This material is produced by passing a fibrous (dry-laid) web into a needle punch machine equipped with groups of specially designed needles.
Bonded-Web Nonwovens
-Bonded webs can be made with any staple
fiber and are produced by forming a web of
fibers (web can be formed by carding
machine), air blowing fibers (dry-laid) or with
liquid (wet-laid).
- Fibers are bonded with an adhesive or with heat fusion (if the fibers are thermoplastic).
End Uses of Bonded-Web
Nonwovens
-Bonded-web nonwovens can be unidirectional,
cross laid, or random web.
- Bonded nonwovens are used in disposable items
such as: - Hospital protective gowns, disposable bed
sheets, towels, tablecloths, cooks hats. - Brand names include Vileda®, Webril®,
Hydraspun
Spunlaced Nonwovens
- formed by the entanglement of staple fibers, using needlelike, high pressure water jets on the web
(wet-laid). - The fibers knot or curl around each other,
causing mechanical binding. No binders are
used. - End uses include medical robes, mattress pads,
backing of quilted tablecloths and sanitary
products. - Brand names include Sontara® by Dupont.
Spunbonded Nonwovens
-Spunbonded nonwovens are made immediately
after fibers are extruded from spinnerets.
(polymer laid)
- They consist of randomly oriented filament
fibers laid down on a fast moving conveyer
belt, consolidated by thermal bonding,
mechanical entanglement, adhesive bonding or
etched filament surfaces to interlock the
fibers. - Since the fabric production is combined with
fiber production, the process is generally more
economical than when using staple fiber to
make nonwoven fabrics.
End uses of Spunbonded Nonwovens
-carpet backing, geotextiles, clothing
interliners, shoelinings, envelopes (Tyvek®), disposable
medical products.
- This method produces the second largest amount of
nonwovens.
Melt-Blown Nonwovens
-made by extruding the polymer through a single-extrusion orifice into a high-velocity, heated-air stream that
reduces the filaments to microdenier size and breaks the filaments into staple fibers.
-The fibers are propelled onto a collection
surface and are held together by a
combination of fiber interlacing and thermal
bonding.
-The fiberweb strength is low and abrasion
resistance is low.
Melt-Blown Nonwovens end-use
insulation (Thinsulate®),
hospital/medical products,battery separators.
Fusible Nonwovens
- made from either thermoplastic fibers (thin spiderweb like fabric of thermoplastic filaments) or thermoplastic films.
- Fusible nonwovens are used primarily as
interling for clothing and have 2 major
functions:
- Provide shape to cut parts of garments and
- To hold garments parts like a skirt hem or
shirt facing together.
Bonded Materials
-made from 2 fabrics that have been adhered together. (swatch#68)
- Bonded fabrics are made from lightweight
face fabrics that alone are unsuitable as
apparel fabric. When bonded to a tricot
backing, they become more stable, and heavier
and become more suitable for an end use. - tricot backing is low cost and bonding is fast and economical, bonded fabrics provide the consumer with relatively low cost fabrics that have the appearance and hand of higher cost materials.
2 methods of producing bonded fabrics
- Wet–adhesive process: adhesives are applied
to the fabric and the fabric is passed between
hot rollers to activate and set the adhesive.
(fig. 7.4 pg. 165). - Foam-flame bonding: uses an extremely thin
layer of polyurethane foam that is heated to
make it tacky and adhesive. The tacky foam is
then sandwiched between the face and back
fabric. The foam is heated over gas jets. The
foam is melted and practically disappears, a
thin layer of about 1/100 inch remains
between the face and back and gives body to
the cloth.
Foam-Laminated Fabrics
- Similar to foam-flame bonded materials,
except a thicker layer of foam is used. The
foam remains as a laminate when the process
is completed. Foam laminate size ranges from
1/8 to 3/16 inch.
-primarily used for clothing insulation. They are lightweight and their cellular structure entraps dead air
- End Uses for foam-laminates include winter
coats and sportswear.
FELT
- Felt is an excellent shock-absorbing and
sound-absorbing material. - It has poor drapability, low tensile strength,
does not return to shape if stretched and a
propensity to form holes and tears that cannot
be mended. - Felt should not really be considered a
nonwoven fabric as it is the interlocking of the
fiber surface serrations that holds the fibers
together, not adhesive, fusion or mechanical
binding.
Mali Fabrics
- Mali (also known as stitch bonding) is a
technique for producing and reinforcing other
fabrics. - Mali fabrics are constructed by a system in
which needles and threads are used to sew or
stitch yarns or fibers together. - Mali fabrics are used mostly in industrial
fabrics, carpets and upholstery.
Lace Fabrics
- 2 other fabrics marketed as lace but not made
on lace- making machine: - Raschel lace: a knitted lace made on a Raschel
knitting machine. Most widely used lace
material, can be inexpensive or high price
couture material. - Schiffli lace: made by the Schiffli machine
and uses an embroidery technique.
Embroidery
- The designs are produced with needles and
thread, using one or many colours to produce
raised designs on the fabric. - Most machine-made embroidery sold in the
U.S. is made on the Schiffli machine and the
embroidery is called Schiffli embroidery.
Schiffli Embroidery
- Schiffli embroidery is often done on lightweight fabrics (batiste and lawn) for delicate embroidery. It can also embroider heavier fabrics.
- When Schiffli embroidery is done on net
fabrics, the fabric is called Schiffli lace.
