2. Light is very essential on earth.
Source of light on earth is SUN
3. Ultraviolet
Radiations are
electromagnetic rays
with a wavelength
between 100-400nm.
Solar UVR that
reaches earth have
wavelength
between 290-400nm.
4. U.V rays has three regions depending upon
wavelength:
Ultraviolet region – A (UVA)
Ultraviolet region – B (UVB)
Ultraviolet region – C (UVC)
5. Region Wavelength(n Relative Av. Photon
m) Intensity(%) Energy(kj/mol)
UV-A 315-400 3.2 315
UV-B 280-315 2.4 350
UV-C 100-280 0.5 400
6. Sun angle
Geographical Position
Seasonal Effects
Clouds
Ozone
Scattering
Altitude
Time of day
7. Human Skin
The major effects of
UV are sunburn,
erythema(skin
reddening), skin
cancer, DNA
damage.
8. Protection factor is used to quantify the
protective effect of material.
SPF/UPF is the ratio of actual potential
erythemal effect to the erythemal effect
transmitted through the fabric.
Larger the UPF/SPF, the more protective the
fabric to UV radiation.
9. where
Sλ is Solar spectral irradiance in Wm-2nm-1
Eλ is relative erythemal spectral effectiveness
T λ is spectral transmission of object
∆ λ is band width in nm
λ is wavelength in nm
ED is effective dose of UVR for unprotected skin
EDM is the effective dose of UVR for protected skin
10. UPF depends upon following factors:
Cover Factor
THE MORE THE COVER FACTOR, HIGH IS UPF
Color
Humidity
THE UPF INCREASED AS THE RELATIVE
HUMIDITY INCREASED, BUT THIS INCREASE IS
FIBRE DEPENDENT, MORE PRONOUNCED IN
IN VISCOSE & SILK
13. Effect Of UVR On Textile Material:
U.V radiations cause degradation of textile
materials due to excitations in some parts of the
polymer molecule.
This results decrease in elasticity, tensile
strength.
For example:
Fabric % Loss In Tensile
Strength
Nylon 100
Cotton 34
14. When solar radiations impinge on a textile , the radiation can be
completely reflected, dispersed & absorbed
There are two possibilities of reducing UV transmittance by fabrics
•To optimize the fabric construction so as to increase the skin cover by
fibers, which can be achieved by spacing the yarns as closely as
possible. UV transmittance can also be reduced by improving the
absorption & reflection properties
• By use of UV absorbers
15. UV absorbers are colorless compounds with
very strong absorption in the UV range of 290-
400nm.
UV Absorbers incorporated into fibres convert
electronic excitation energy into thermal
energy.
They function as radical scavengers and
oxygen scavengers.
16. Highest absorbency in the ultraviolet region {290-
340nm} and no absorbency in the visible region.
UV Absorbers should be non-toxic and non-skin
irritant.
These should be heat stable and compatible with
other additives in finish formulation.
It should remain stable against UVR itself.
It should be suitable for use in powder, liquid
detergents and rinse conditioners.
17. UV Absorbers are of two types:
Organic Absorbers
Inorganic Absorbers.
Organic Absorbers:
These are derivatives of O-hydroxy
benzophenone, O-hydroxyphenyl
benzotriazole and O-hydroxy phenyltriazine.
18. These are applied by normal padding, coating,
pad thermosol process.
These have excellent sublimation fastness and
self dispersing formulation.
In these, orthohydroxy group is for absorption
and to make soluble alkaline solution.
Inorganic Absorbers:
These are compounds of Titanium oxide and
ceramic materials.
These have an absorption capacity in the UV
region of 290-400nm.
19. UV absorption
causes the electron
density to move
from the phenolic
oxygen to the
nitrogen atom.
20. The nitrogen becomes more alkaline than the oxygen
as a result and a proton transfer occurs.
This mesomeric form represents an excited
state, which stabilizes as a result of a radiation less
transition to the ground state.
21. UV Absorbers are incorporated either into
spinning dope prior to fibre extrusion or in
dyeing.
These are applied by normal padding, exhaust,
pad dry cure and pad thermosol methods.
These are applied between 30-40g/lt.
The concentration depends on type of fibre and
its construction.
22. COMMERCIALLY AVAILABLE UV ABSORBERS
•RAYOSAN PRODUCTS
INCLUDES RAYOSAN C PASTE, RAYOSAN CO LIQ. & RAYOSAN P LIQ.
•RAYOSAN C & RAYOSAN CO LIQ. ARE DESIGNED FOR CELLULOSIC,
POLY AMIDE & WOOL FIBRES. THEY BIND WITH FIBRE IN THE SAME
WAY AS A REACTIVE DYE
TEMPERATURE RANGE-70-95◦ C
THESE PRODUCTS ABSORB MAINLY IN THE UV B REGION.
THE ABSORBING EFFECT DEPENDS UPON THE VOLUME APPLIED
RAYOSAN P LIQIS DESIGNED FOR FINISHING PET & ACETATE FIBRES
& CAN BE APPLIED TOGETHER WITH THE DISPERSE DYES.
IT HAS HIGH ABSORPTION IN THE TOTAL UV REGION
23. UV ABORBERS BY CIBA
•TINO FAST CEL(BI-REACTIVE OXALIC ACID DI-ANILIDE DERIVATIVE)
•THE DEGREE OF EXHAUTION & FIXATION IS EXCELLENT
• COMPATIBLE WITH CIBACRON LS & CIBACRONE FN DYES
•REQUIRES VERY LESS AMOUNT OF SALT TO MAXIMISE BATH EXHAUTION
•HIGH AMOUNTS MAY LEAD TO SHADE VARIATIONS
TINO FAST PES
•DESIGNED FOR PET & ACETATE
•IT IS REQUIRED IN VERY LESS AMOUNT AS PET ITSELF CONTAINS
DELUSTERANTZ(TIO2), WHICH ITSELF IS A UV ABSORBER