Fabric Identification – The burn test

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Fabric Identification
Fabric Identification – The burn test
CAUTION. WARNING. BE CAREFUL! This should only be done by skilled burners! Make sure there is a bucket of
water nearby and that you burn in a metal bucket or non-plastic sink.
To identify fabric that is unknown, a simple burn test can be done to determine if the fabric is a natural fiber, man
made fiber, or a blend of natural and man made fibers. The burn test is used by many fabric stores and designers
and takes practice to determine the exact fiber content. However, an inexperienced person can still determine the
difference between many fibers to “narrow” the choices down to natural or man made fibers. This elimination process
will give information necessary to decide the care of the fabric.
WARNING: All fibers will burn! Asbestos treated fibers are, for the most part fire proof. The burning test should be
done with caution. Use a small piece of fabric only. Hold the fabric with tweezers, not your fingers. Burn over a metal
dish with soda in the bottom or even water in the bottom of the dish. Some fabrics will ignite and melt. The result is
burning drips which can adhere to fabric or skin and cause a serious burn.
Fabric Identification – Natural Fibers
Natural Fibers are a class of hair-like materials that are continuous filaments or are in discrete elongated pieces,
similar to pieces of thread. They can be spun into filaments, thread, or rope. They can be used as a component of
composite materials. They can also be matted into sheets to make products such as paper or felt. Fibers are of three
types: natural fiber, cellulose fiber, and synthetic fiber. The earliest evidence for humans using fibers is the discovery
of wool and dyed flax fibers.
Cotton is a plant fiber. When ignited it burns with a steady flame and smells like burning leaves. The ash left is easily
crumbled. Small samples of burning cotton can be blown out as you would a candle.
Linen is also a plant fiber but different from cotton in that the individual plant fibers which make up the yarn are long
where cotton fibers are short. Linen takes longer to ignite. The fabric closest to the ash is very brittle. Linen is easily
extinguished by blowing on it as you would a candle.
Silk is a protein fiber and usually burns readily, not necessarily with a steady flame, and smells like burning hair. The
ash is easily crumbled. Silk samples are not as easily extinguished as cotton or linen.
Wool is also a protein fiber but is harder to ignite than silk as the individual “hair” fibers are shorter than silk and the
weave of the fabrics is generally looser than with silk. The flame is steady but more difficult to keep burning. The
smell of burning wool is like burning hair.
Fabric Identification Man Made fibers
Man Made Fibers, often referred to as synthetic fibers, are the result of extensive research by scientists to improve
upon naturally occurring animal and plant fibers. In general, synthetic fibers are created by forcing, usually through
extrusion, fiber forming materials through holes (called spinnerets) into the air, forming a thread. Before synthetic
fibers were developed, artificially manufactured fibers were made from cellulose, which comes from plants. These
fibers are called cellulose fibers.
Synthetic Fibers account for about half of all fiber usage, with applications in every field of fiber and textile
technology. Although many classes of fiber based on synthetic polymers have been evaluated as potentially valuable
commercial products, four of them – nylon, polyester, acrylic and polyolefin – dominate the market. These four
account for approximately 98% by volume of synthetic fiber production, with polyester alone accounting for around
60%.
Acetate is made from cellulose (wood fibers), technically cellulose acetate. Acetate burns readily with a flickering
flame that cannot be easily extinguished. The burning cellulose drips and leaves a hard ash. The smell is similar to
burning wood chips.
Acrylic technically acrylonitrile is made from natural gas and petroleum. Acrylics burn readily due to the fiber content
and the lofty, air filled pockets. A match or cigarette dropped on an acrylic blanket can ignite the fabric which will burn
rapidly unless extinguished. The ash is hard. The smell is acrid or harsh.
Nylon is a polyamide made from petroleum. Nylon melts and then burns rapidly if the flame remains on the melted
fiber. If you can keep the flame on the melting nylon, it smells like burning plastic.
Polyester is a polymer produced from coal, air, water, and petroleum products. Polyester melts and burns at the
same time, the melting, burning ash can bond quickly to any surface it drips on including skin. The smoke from
polyester is black with a sweetish smell. The extinguished ash is hard.
Rayon is a regenerated cellulose fiber which is almost pure cellulose. Rayon burns rapidly and leaves only a slight
ash. The burning smell is close to burning leaves.
Blends consist of two or more fibers and, ideally, are supposed to take on the characteristics of each fiber in the
blend. The burning test can be used but the fabric content will be an assumption for fabric identification.
Use a butane lighter to melt or ignite an unknown fiber to determine its type. Never use
a match. The purpose of using a butane lighter is to avoid masking the odor of the
burning fiber since the butane flame is odorless.
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Acrylic:
Melts and shrinks from an approaching flame and ignites quickly. In the flame,
burns rapidly with bright, sputtering flame with a lot of smoke. When withdrawn
from the flame, it continues to burn, melts, and drips. It has an acrid odor and
results in a hard, irregular black bead.
Cellulose:
Cellulosic fibers, such as cotton, burns and the ash crumbles – as do protein
fibers such as wool and silk.
Corterra:
Similar to polyester.
Cotton/Linen:
Cellulosic fibers such as cotton and linen ignite readily with an approaching flame
and scorches. Once in the flame, it burns rapidly with yellow flame. When pulled
out of the flame, it continues to burn rapidly with a red afterglow upon
extinguishing. Smells like burning paper. Its burned residue is a gray to charcoal
colored light feathery ash, which easily crumbles.
Nylon:
Melts and shrinks from an approaching flame. In the flame, melts and burns
slowly and is smoky. Once out of the flame, burns slowly and tends to self-
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extinguish. Burning nylon smells like celery. Its burned residue is a hard, shiny
brown or gray bead.
Polyester:
Melts and shrinks from an approaching flame. In the flame, melts and burns
slowly. When withdrawn from the flame, it burns slowly, melts and drips. Has a
slightly sweet smell. It produces a hard, shiny black or brown bead.
Polypropylene (Olefin):
Melts and shrinks from an approaching flame. In the flame, it melts and burns.
When withdrawn from the flame, it continues to burn. It has a candle wax odor
and produces a tough, tan bead.
Protein:
Protein fibers, such as wool, burns and the ash crumbles – as do cellulosic fibers
such as cotton.
Rayon:
Scorches and ignites readily with an approaching flame. In the flame, burns
rapidly with a blue flame. When withdrawn from the flame, continues to burn
rapidly with a red afterglow when the flame is extinguished. Smells like burning
paper, leaves a gray to charcoal color light feathery ash.
Silk:
Curls away from an approaching flame. In the flame, it burns slowly and sputters.
Weighted silk glows red. Out of the flame, it is self-extinguishing or may burn
very slowly and smells like singed hair. Its residue is round, shiny black beads,
easily crushed. Weighted silk has the skeleton of the original fiber.
Wool:
Chars and curls away from an approaching flame. In the flame, it burns slowly
and unevenly. Once pulled out of the flame it is self-extinguishing. It smells like
burning hair. It has a brittle, irregular black ash. As with cotton and linen, protein
fibers’ ashes readily crumble.
Cotton
Cotton ! Cool, soft, comfortable, principal clothing
fiber of the world.
Its production is one of the major factors in world prosperity
and economic stability. Cotton “breathes”. What would we do without cotton? Since cotton wrinkles, polyester was
added to give it wash and wear properties for a busy world. In recent times, the consumer determined that polyester,
although easier to care for, took away the cool from cotton and also added a “pilling” effect to cotton/polyester blends.
Consumers now often request “100% Cotton”. Permanent finishes also added to the all cotton fabric gave a wash and
wear property to cotton. The cotton fiber is from the cotton plant’s seed pod The fiber is hollow in the center and,
under a microscope looks like a twisted ribbon. “Absorbent” cotton will retain 24-27 times its own weight in water and
is stronger when wet than dry. This fiber absorbs and releases perspiration quickly, thus allowing the fabric to
“breathe”. Cotton can stand high temperatures and takes dyes easily. Chlorine bleach can be used to restore white
garments to a clear white but this bleach may yellow chemically finished cottons or remove color in dyed cottons.
Boiling and sterilizing temperatures can also be used on cotton without disintegration. Cotton can also be ironed at
relatively high temperatures, stands up to abrasion and wears well
Linen
Linen ! The elegant, beautiful, durable, the refined
luxury fabric.
Linen is the strongest of the vegetable fibers and has 2 to 3 times the strength of cotton. Linen table cloths and
napkins have been handed down generation to generation. Not only is the linen fiber strong, it is smooth, making the
finished fabric lint free. Fine china, silver and candles are enhanced by the luster of linen which only gets softer and
finer the more it is washed.
Linen Made from?
Linen is from flax, a bast fiber taken from the stalk of the plant. The luster is from the natural wax content. Creamy
white to light tan, this fiber can be easily dyed and the color does not fade when washed. Linen does wrinkle easily
but also presses easily. Linen, like cotton, can also be boiled without damaging the fiber.
Highly absorbent and a good conductor of heat, this fabric is cool in garments. However, constant creasing in the
same place in sharp folds will tend to break the linen threads. This wear can show up in collars, hems, and any area
that is iron creased during the laundering. Linen has poor elasticity and does not spring back readily.
Silk
Silk ! This is the fabric that makes its own statement.
Say “silk” to someone and what do they visualize? No other fabric generates quite the same reaction. For centuries
silk has had a reputation as a luxurious and sensuous fabric, one associated with wealth and success. Silk is one of
the oldest textile fibers known to man. It has been used by the Chinese since the 27th century BC. Silk is mentioned
by Aristotle and became a valuable commodity both in Greece and Rome. During the Roman Empire, silk was sold
for its weight in gold.
Today, silk is yet another word for elegance, and silk garments are prized for their versatility, wearability and comfort.
Silk, or soie in French, is the strongest natural fiber. A steel filament of the same diameter as silk will break before a
filament of silk. Silk absorbs moisture, which makes it cool in the summer and warm in the winter. Because of its high
absorbency, it is easily dyed in many deep colors. Silk retains its shape, drapes well, caresses the figure, and
shimmers with a luster all its own.
Contemporary silk garments
Contemporary silk garments range from evening wear to sports wear. A silk suit can go to the office and, with a
change of accessories and a blouse, transform into an elegant dinner ensemble. Silk garments can be worn for all
seasons.
Silk — elegant, versatile and washable. In the past, owning a silk garment meant not only the initial price of the
garment but also the cost of dry cleaning. All silk is washable. Silk is a natural protein fiber, like human hair, taken
from the cocoon of the silkworm. The natural glue, sericin, secreted by silkworms and not totally removed during
manufacturing of the silk, is a natural sizing which is brought out when washing in warm water. Most silk fabrics can
be hand washed. Technically, silk does not shrink like other fibers. If the fabric is not tightly woven, washing a silk will
tighten up the weave…. thus, lighter weights of silk (say a crepe de chine of 14 mm) can be improved by washing as
it will tighten up the weave. A tightly woven silk will not “shrink” or will “shrink” a lot less. Silk garments, however, can
shrink if the fabric has not been washed prior to garment construction. When washing silk, do not wring but roll in a
towel. Silk dries quickly but should not be put in an automatic dryer unless the fabric is dried in an automatic dryer
prior to garment construction. A good shampoo works well on silk. It will remove oil and revitalize your silk. Do not
use an alkaline shampoo or one which contains ingredients such as wax, petroleum, or their derivatives, as these
products will leave a residue on your silk and may cause “oil” spots. If static or clinging is a problem with your silks, a
good hair conditioner (see above cautions) may be used in the rinse water.
Wool
Wool fabric – The warm, cozy and incredibly soft fabric.
Wool is actually quite soft and luxurious. Some wools are scratchy giving some people the idea that they are “allergic”
to wool. Although wool fiber comes from a variety of animal coats, not all wools are scratchy but rather extremely soft.
The wool fibers have crimps or curls which create pockets and gives the wool a spongy feel and creates insulation for
the wearer. The outside surface of the fiber consists of a series of serrated scales which overlap each other much like
the scales of a fish. Wool is the only fiber with such serrations which make it possible for the fibers to cling together
and produce felt. The same serrations will also cling together tightly when wool is improperly washed and shrinks!
Wool will not only return to its original position after being stretched or creased, it will absorb up to 30% of its weight
in moisture without feeling damp. Its unique properties allow shaping and tailoring, making the wool the most popular
fabric for tailoring fine garments. Wool is also dirt resistant, flame resistant, and, in many weaves, resists wear and
tearing.
Basically, there are two different processes used in wool production. Woolen fabrics have a soft feel and fuzzy
surface, very little shine or sheen, will not hold a crease, and are heavier and bulkier than worsteds. Blankets,
scarves, coating, and some fabrics are considered woolens. Worsted wool is smoother than woolen, takes shine
more easily, does not sag, holds a crease well, is lighter and less bulky, and wears longer than woolen. Worsted
wools require a greater number of processes, during which fibers are arranged parallel to each other. The smoother,
harder-surface worsted yarns produce smoother fabrics with a minimum of fuzziness and nap. Fine worsted wool is
even seen in clothing for athletics such as tennis. No, they are not hotter than polyester but actually cooler, as the
weave of the fabric allows wool to absorb perspiration and the fabric “breathes,” unlike polyester.
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