Swimwear Fabrics Basic Characteristics & Development Dr. Jimmy Lam

Swimwear Fabrics
Basic Characteristics &
Development
Dr. Jimmy Lam
Institute of Textiles & Clothing
Swimwear Fabrics
Agenda
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Swimwear Fabric Historical Development
Swimwear Fabric Characteristics
Swimwear Material: Spandex
Fiber & Fabric Requirements
Caring of Swimwear Fabrics
New Development (1): UV protection
New Development (2): Competitive Swimming
New Development (3): DuPont Sorona
Historical Development of
Swimsuit Fabrics (I)
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In the 1920s, swimsuits were made in pure silk, for lightness,
while racing and training costumes were made from cotton.
Navy blue was the only colour option.
Silk was more costly than cotton, but it had several advantages:
lightness, strength, elasticity and feel.
Extensive use of silk and cotton continued through 1930s and
1940s.
In 1957, Australian swimmer Dawn Fraser developed a new
competitive swimsuit for Speedo- fabric with nylon.
On the synthetics, nylon was the most favoured because of its
strength, elasticity and the ease with which it took colour with
dyed.
Historical Development
Swimsuit Fabrics (II)
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Nylon is light in weight, water repellent quality which
meant it was quick drying.
With the introduction of nylon, colours other than navy
began to appear. Red, royal blue were the most popular.
In 1972 Munich Olympic Games, Lycra was introduced.
It has excellent stretch properties and good recovery and
lightness.
The durability of this elastomeric fibre was not a par
with nylon. However, the high cost of Lycra was
restricted to competitive swimwear fabrics, rather than
all-purpose wear, in which nylon remained dominant.
Today’s Swimwear Fabrics
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There have been many developments in swimwear
fabrics today. For example:
– Sun Select fabric from Triump allows tanning through the
swimsuit; it has been designed to block harmful UV rays to
penetrate to the skin.
– Speedo’s Scubasuit is made in a dense fabric which has a
sun protection factor (SPF) of over 30, dry or wet to help the
wearer practise “safe sun”.
– Triump has developed a material which is quick drying,
handy for swimming holidays. It is a mixture of nylon and
Lycra with a layer of Telfon, meaning water rolls off the
surface of the suit.
Basic Characteristics (I)
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Opacity
– i.e. not able to see through when wet (by adding acetate/nylon
for liner)
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Higher order of stretch and recovery
– One of the most important properties of fabric that is intended
for swimwear is recoverable stretch or elasticity
– swimwear fit the figure tightly, and must be stable to elongation
when wet
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Higher order of resistance to abrasion
Basic Characteristics (II)
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Higher fabric bursting strength
– used for tight-fitting beach styles, fibers and yarns
are important
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Colour fastness to light
– under explore under strong sunlight
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Colour fastness to sea and pool water
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Given the requirement for knitted fabric, what
kind of stitch and structure are suitable for
swimwear ?
Spandex Fiber (I)
Introduction
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In textiles, the man-made fibre with high degree of
elasticity used for swimwear is known as Spandex.
Spandex is composed of at least 85% polyurethane by
weight.
Such fibres are generally used for their highly elastic
properties.
Trademarked fibres in this group are Lycra, Numa,
Sapndelle and Vyrene.
Such fibres have, for many textile purposes, largerly
replaced natural and synthetic rubber fibers.
Spandex Fiber (2)
Characteristics
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Although somewhat weak in the relaxed state, Spandex fibres can be
stretched about 500-600 percent beyond their length without breaking
and quickly return to their original length.
The fibre, usually white and dull lustre, is readily dyed and absorbs
very little moisture.
The fibre melts at 250 C and yellows upons prolonged explore to heat
or light.
Items made of Spandex can be machine washed and dried at moderate
temperatures.
Use of chlorine bleach can produce yellowing.
Spandex fibres are frequently covered with other fibres like nylon.
Spandex Fiber (3)
End uses
Spandex is used in such apparel as foundation
garments. Support hosiery and swimsuits.
 It is light in weight and cool.
 It is resistant to deterioration from body acids
and it is easily laundered and quick-drying
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Source: Briantanna Encyclopedia 2004
Fibres for swimwear
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Nylon is used for most swimwear. Man-made, nylon is strong,
abrasion-resistance and lightweight.
Polyester is also strong, resilient, wrinkle resistance and
washes easily. Best when used in blends with cotton.
Cotton is a natural fibre which is strong, inexpensive and
absorbent and comfortable in hot weather.
– (But it is heavier in weight and wet easily)
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Elastane is a synthetic stretch fibre which is present in most
swimwear, being blended with nylon, polyester or cotton. It
gives swimwear its stretch and resilience.
Fiber and Yarn
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Generally, textured filament with modified into stretch
yarn on false twist are more appropriate for use in
swimwear than spun yarn (nature fiber)
For spun yarn, worsted system yarn is preferred over
woolen system for swimwear, with high twist factor
(finer and stronger yarn for knitting)
Swimwear Material
Speedo: P.B.T. Endurance
One piece swimsuit from 45%
polyester and 55% P.B.T. , a
polyester variant, giving
superior recovering properties
Fabrics for swimwear
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Tricot is a technique of knit which produces adequate
two-way stretch. Either smooth or structured, lustrous
or matt, plain or printed
Jersey is used mainly in cotton and cotton polyester
blends. Elastomeric is required for stretching and body
fitting.
– (Which structure is better for swimwear, single knit or
double knit?)
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Wovens are mainly used for coordinated breach wear
items such as skirts and shirts.
– Can we use woven fabric for swimwear?
Fabric Structure (I)
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Amongst all knitted fabrics which are not made from stretch yarns and
do not have rubber threads, the most elastic structure is 1x1 rib
Rib structure is better for swimwear (instead of plain) because
– rib structure trends to be more opaque (without adding lining) and
more dense;
– rib structure is more elastic than single jersey (single jersey can
add elastic yarn to overcome it)
Common Rib structure for swimwear
– interlock
– swiss pique
using stretch nylon and stretch polyester with /without spandex.
Swimwear Knit Structure:
Warp Knit Structure
Speedo: S2000
One piece swimsuit from a warp
knitted polyester elastane fabric
with high filament polyester micro
fiber yarns and finished with
thermal treatment
Fabric Structure (II)
In whatever structure, the necessary elasticity is
achieved by either laying-in or knitting-in
elastomeric yarn, preferably spandex over
rubber because of its lighter weight.
 The fabric stretch is affected by:
– the fabric structure
– whether the elastomeric yarn is used in bare or
covered form
Fabric Structure (III)
A covered form yarn (spandex with an outer
sheath of yarn) will normally restrict on its
elasticity
 The degree on its extension and return from
elongation will depend on the amount of covering.
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Caring for swimwear
Always warm hand wash with mild soap, rinse
after wear in cool water, drip dry out of direct
sunlight.
 Do Not use strong detergents or bleach roll up
when wet dry clean or iron tumble dry.
 Avoid contact with rough surfaces, excessive
contact with suntan lotions and oils harsh
chemicals present in some pools or hot spas.
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New Development
Lessons from Australia
Apart from design, stretch and fit, new
developments are needed for modern swimwear.
 They are Ultra-Violent (UV) protection and
reduce water friction for Olympia game
(Competitive Swimming)
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UV protection swimwear (1)
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The effects of UV radiation are considered to be
cumulative.
Apart from direct exposure to the sun, the reflection off
the water or sand can give you increase dose of UV.
The risk of sunburn is much greater high on a
mountain slope because UV increases by around 15%
for every 1000 meters above sea level.
Hats sun glasses and scientifically designed fabrics for
clothing provide the best protection against sun
damage to skin.
Sun Protection (UV radiation)
Swimsuit for children.
The swimsuit covers all the body
With high percentage of Lycra
UV protection swimwear (2)
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Research from the University of New South Wales
under the Dept of Fibre Science and Textiles is
conducted programme in sun protection, structures and
rating for making UV protective swimwear.
Initial work found that:
– Lycra fibres provide high UV rating (strong protection),
however, they never exceed 20% of fibre content.
– Cotton fibres when wet (under water) decreases in UV rating
by as much as 50% (reduce protection)
– Knitted fabrics will also stretch and UV rays can penetrate
such open structure, especially on shoulders.
– Colour of the fabric play a significant role too.
Ultraviolet Protection Factor (UPF)
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Over-exposure to solar ultraviolet radiation (UVR) can cause
sunburn, skin damage and increased risk of skin cancer.
Clothing provides one of the most convenient forms of
protection against UVR but not all garments offer sufficient
sun protection.
The UPF rating indicates how effective a fabric is at blocking
out solar ultraviolet radiation. The testing is performed
according to Australian /New Zealand standard AS/NZ4399.
UPF ratings range from 15 to 50 with higher ratings
indicating more effective blocking and therefore better
protection for the wearer of a garment made from the fabric
Factors affecting UPF Rating
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Composition of the yarns (Polyester, cotton)
Tightness of the weave or knit (tighter improves the
rating)
Colour (darker colours are generally better)
Stretch (more stretch lowers the rating)
Moisture (many fabrics have lower ratings when wet)
Condition (worn and faded garments may have
reduced rating)
Finishing (some fabrics are treated with UV absorbing
chemicals)
Competitive Swimwear
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Besides UV protection, there was an emphasis on practical
swimwear, especially in competitive swimming.
Olympic swimmers felt better in one piece swimsuits such as
skin suit.
In 1972 Munich Olympic game, these suits were manufactured
from very fine cotton that became virtually transparent when wet.
Today, this skin suit was made from a thin, light weight
Lycra/nylon mixture, which would cling closely to the body and
reduce drag.
Reducing drag for competitive swimming has been a goal for
designers and manufacturers, and Swiss Olympic swimmers in
1972 decided to wear suits which were glue around the neck, leg
and arm openings, which prevented water and air bubbles from
entering the suits.
Competitive Swimwear for Olympia Game
Training suit with a high
neck from 80% nylon, 20%
Lycra. It is soft and sticky
to touch, lightweight, fast
drying. And offers
resistance to chlorine.
Source: Maru Skooba
Competitive Swimsuit for Olympia Game
Speedo: Aquablade
One piece swimsuit from
Polyester/Lycra. With high
neckline, boy short legs and
silicon ridges
Competitive Swimwear (2)
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Arena and Speedo, two major swimsuits
manufacturers, produced swimsuits for Montreal
Olympia, worn by American, British, Russian teams.
The major advantage was that the body was completely
compressed by suit.
The embarrassment caused by the suit’s transparency
was reduced by the use of highly coloured patterns.
New Fiber Development from
Du Pont: Sorona
New Development
DuPont Sorona
Sorona® polymers have a unique combination
of characteristics that help create softer fibers
with superior comfort-stretch and recovery.
Unlike nylon or polyester, the Sorona® dyeing
process makes it possible to create a single
fabric with many different colors in it at
atmospheric temperatures.
Untextured Fiber Recovery versus Stretch as a function of
polymer content
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Both flat and textured yarns
made from Sorona® fibers may
be made into fabrics with
advanced levels of comfort fit.
As shown in the chart, fully
drawn flat yarn made with
Sorona® recovers 100% from
approximately 120% strain.
Even at higher levels, Sorona®
fibers recover completely,
returning to their initial form.
DuPont Sorona
Softness
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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 curves in the chart
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. Nonwovens, such as
medical garments, monofilaments and
brushes, are softer and more resilient
with Sorona
Smart Fibre
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These unique properties — combined with fast drying,
colorfastness, chlorine resistance, resilience, static
protection, stain resistance, and easy care — make
fibers made with Sorona® the obvious choice for a
wide range of apparel applications, including casual
wear, ready-to-wear, swimwear, activewear, outerwear
and intimate apparel. Fabrics made with Sorona® soon
will be available to apparel companies and top garment
designers.
Sorona Swimwear
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Alone or blended with other fibers, DuPont™ Sorona®
offers all of the smart characteristics designers,
manufacturers and consumers look for in swimwear:
Bright color vibrancy for deeper, richer colors
UV and chlorine resistance for brilliant color
performance
Incredible print clarity and crisp color definition
Colorful good looks that last, swim after swim
DuPont Sorona: Performance Attributes
Comfortable, easy-care swimwear made with Sorona®.
Discussion
What kind of fibers are used for swimwear?
 What kind of knitting structures are suitable for
swimwear?
 What are the requirements for competitive
swimwear?
 What are the latest developments of fiber
technology for swimwear?
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