Md.sayeed ahmed Daffodil International University Textile physics - Swelling of yarn

1. Welcome to My Presentation
TOPIC: SWELLING OF YARN

3. Swelling Property
 When the fibers absorb water, they change dimensionally
(length, diameter, area). Swelling occurs in transverse
direction (width wise) and axial direction (length wise). It can
be expressed in terms of increase in diameter, length, area
and volumes. That means the dimensionally changes due to
absorbing water or moisture by any fiber is termed as swelling
property.

4. Types of swelling
 1. Transverse dial swelling
 2. Transverse area swelling
 3. Axial swelling
 4. Volume swelling

5.  1. Transverse dial swelling: Fractional increase in diameter of a fiber after swelling is
called transverse dia swelling.
Mathematically,
Transverse dia swelling, SD = ∆D / D
Where, D = original diameter of fiber, ∆D =increased diameter of swollen fiber.
 2. Transverse area swelling: Fractional increase in area of a fiber after swelling is called
transverse area swelling.
Mathematically,
Transverse area swelling, SA = ∆A / A
Where, A = original area of fiber, ∆A =increased area of swollen fiber.

6.  3. Axial swelling: Fractional increase in length of a fiber after swelling is called
axial swelling.
Mathematically, Axial swelling, SL = ∆L / L
Where, A = original length of fiber, ∆L =increased length of swollen fiber.
 4. Volume swelling: Fractional increase in volume of a fiber after swelling is called
volume swelling.
Mathematically,
Volume swelling, SV = ∆V / V
Where, V = original Volume of fiber, ∆V =increased volume of swollen fiber.

7. Importance of Swelling
 Improve the absorption capability of dyes and chemicals.
 It has technical consequences in the dimensional stability of the fabric, the
predominant transverse swelling measurement.
 Due to swelling the pores of interlaced structure will be blocked, this idea
is used to produced shower proof fabric.
 Improve fastness of dyed materials.
 Elastic properties changed.
 Static Electricity is reduced.

8. Rates of swelling Depends on
 Size and form of the sample, such as - fiber, yarn, fabric etc.
 Composition of the material, such as - cotton, polyester, acrylic, nylon etc.
 External condition, i.e. Temperature.
 Chemical content, i.e. oil, wax and other impurities.