the ppt provides information on Flax fibers. this discusses the manufacturing process, properties and uses of flax fibers

1. Fiber to Fabric
Dr. Ritu Madhan

2. Flax fibers are used to produce
linen yarns and fabrics.
Eco friendly fiber as it grows
virtually without the use of
herbicides and pesticides.
Leading cultivators-Poland,
Belgium, France, Netherlands
and the Slovakian countries.

3. The botanical
name - Linum
usitatissimum.
Usitastissimum -
Latin for “most
useful”.
Different varieties
of plants are
grown for fiber
and seeds.
The plant grows to
a height of two to
four feet and
produces flowers
with blue or white
petals.
The fibers grow in
bundles in the
bast layer just
underneath the
bark
Large amounts of
woody material
must be removed
to extract the fiber.

4. Cultivation and
Harvesting
Plants are different for seeds and
fibers
Plants for fibers are taller with
fewer branches
Thrives best in temperate
climates with adequate rainfall.
Harvested 80-100 days after
sowing (when about half the
seeds are ripe and leaves have
fallen off)
Harvested by hand or by pulled
by machines
Pulled completely from the
ground
This retains a long stem and
prevents discoloration
Stalks are dried sufficiently so
that they can be threshed,
combed or beaten to remove the
seeds
Seeds are used for future sowing
or for making linseed oil or food
for cattle.

6. Fibers require
extensive
processing to
extract the fibers
from the woody
stem in which they
are held, this adds
to the cost.
The deseeded flax
stems are rotted to
dissolve the
substances that
hold the in the
stem.
This first step of
preparing the
fiber is called
retting.
Retting is
accomplished
through the
breakdown of the
materials that
binds the fiber to
the stem.

7. Retting
Dew
Water
Chemical
Enzyme

8. Most common
method used.
The flax is laid out
in bundles in a field
where the action of
rain and dew
together with soil
fungi and bacteria
cause the bark of
the stems to loosen .
Takes 3-6 weeks
depending upon
weather conditions.
After this the bark is
removed and retted
straw bundles are
left to dry.
Advantages:
It does not harm the
environment
Can be easily
mechanized
Disadvantages:
It takes a very long
time.

9. Flax is submerged in water for 6-20 days. Warmer
water hastens the process. Water retting may be
done in ponds vats or in sluggish streams. As in dew
retting the action of bacteria causes the bark to
loosen.
Advantages:
It is a faster process as compared to dew retting.
Produces fine fibers
Disadvantages:
It is an expensive procedure.
Produces odours and pollutants in the retting water.

10. Threshing tool

12. Chemical retting:
This process uses
chemicals like sodium
hydroxide or oxalic acid.
The process is hardly
used.
Enzyme retting:
In this procedure, the
flax stems are exposed
to enzymes under
controlled conditions.
The enzymes act only on
the material holding the
fibers in the bark.

13. Retting only loosens the bark from the stem.
Breaking and scutching separate the fibers from the stem.
Breaking- The flax straw is passed over rollers or crushed
between slated frames. This breaks the brittle woody parts
of the stem, called shive, but does not harm the fiber.
Scutching- The broken straw is passed through beaters that
knock off the broken pieces of the stem.
Scutching can also be done by scrubbing the flax straw with
a flat instrument.

14. Uprooted stalks of flax Breaking
Scutching Linen yarn

15. The fibers are baled and shipped
to spinning mills.
Fibers go through one more
process before they are ready for
spinning -Hackling or combing
This separates the shorter fibers or
tow from the longer fibers or line
fibers, and aligns them parallel
before spinning.
Flax fibers are long and therefore
must be processed on special
machinery.

16. Microscopic structure
 The cross section has an irregular, many-sided shape. It has a central
canal or lumen, but it is smaller and can hardly be seen.
 The longitudinal section looks like a stalk of bamboo. It has crosswise
markings known as nodes or joints.

17. • Unbleached flax varies from a light brown to dark
tan. The different methods of retting produce
differences in color.
Color
•Measures between 5-30 inches. Most longer fiber are
20-30 inches and the tow is not more than 15 inches.
Length
• Smooth long fiber , thus more lustrous than cotton,
but less than manufactured fibers. A special finish
called beetling can be used to increase luster
Luster
• Same as of cotton (1.54). So it is heavier than silk,
polyester, and nylon
Specific
gravity

18. Strength: Flax is
stronger than
cotton, and is
one of the
strongest natural
fibers. It is more
crystalline and
oriented than
cotton and like
cotton gets
stronger when
wet.
Elasticity and
Resiliency: The
elongation,
elasticity and
resilience are
lower than
cotton. Linens
crease and
wrinkle badly
unless given
special finishes.
Flexibility: Not
as flexible as
cotton. Fabrics
made from linen
feel stiff.
Dimensional
stability: Like
cotton, linen has
poor
dimensional
stability and
tends to shrink.
Preshrinking
treatments
prevent
shrinkage.

19. Chemical properties:
 Absorbency and Moisture Regain: Moisture regain of linen is
higher than that of cotton (11-12%). It has very good absorbency and
wicking properties. Thus it is useful for making towels and warm
weather garments.
 Heat and Electrical conductivity: Linen conducts heat more
readily than cotton and is therefore more comfortable in summers.
Since it conducts electricity static charge build-up is prevented.
 Effect of heat: Linen scorches at a higher temperature than cotton.
The burning characteristics are similar to cotton.
 Chemical reactivity: Like cotton, it is destroyed by hot as well as
cold concentrated mineral acids, but not by organic acids, alkalies
and oxidizing agents. Organic solvents used in dry cleaning do not
harm linen.

20. Environmental properties:
 Resistance to microorganisms and insects: If linen is stored moist
or in a damp place, mildew will attack and harm linen. Dry linen is not
attacked. Moth, carpet beetles and silverfish usually do not harm un-
starched linen.
 Resistance to sunlight and ageing: Linen has better resistance to
sunlight than cotton. However over a period of time there is loss of
strength. The resistance of linen to ageing is good especially when
stored in dry conditions. Linen has a tendency to crack at folded
edges.
Uses:
 Traditionally used for making household textiles like table linen, table
linen, curtains, and upholstery
 Used in making woven and knitted garments.
 Used in car interiors.