Fabric finishes

1. Flame Retardant Finishes
Presented By ;
Abhishek kumar Gupta
Amrit Raj
Nikhil Singh

2. Definition
 Flame resistance is defined by ASTM “The property of a material whereby flaming
combustion is prevented , terminated or inhibited following application of a
flaming or non-flaming source of ignition , with or without the subsequent removal
of the ignition source”

3. INTRODUCTION
 Flame-retardant finishes provide textiles with an important performance
characteristic.
 Protection of consumers from unsafe apparel
 Firefighters and emergency personnel require protection
 Floor coverings, upholstery and drapery protection
 The military
 the airline industry
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4. Fabrics and Ignitability
 Textiles consist of highly ignitable materials and are the
primary source of ignition.
 They contribute to rapid fire spread
 Classification on the basis of ignitability
 Flammable
 Flame Proof
 Flame Resistant/Retardant

5. Reduction of ignitability
1: Use of Inorganic materials {Asbestos, Glass etc}
2: Through chemical treatment with FR {Flame Retardant
chemicals}
3: Through modification of the polymer.

6. FLAMMABILITY

7. Polymer combustion
 Natural and synthetic materials
when exposed to a source of
sufficient heat will decompose or
pyrolyse evolving flammable
volatiles. These mix with the air and,
if the temperature is high enough
will ignite.
Polymer
Decomposition Flash Ignition Autoignition
Range/deg C temp/deg C temp/deg C
LDPE 340-440 340 350
Polypropylene 330-410 350-370 390-410
Polystyrene 300-400 345-360 490
PVC 200-300 390 455
Cellulose 280-380 210 400
Decomposition & Ignition temp. with the
heats of combustion of common
thermoplastic polymers and cellulose

8. Mechanisms of flame retardancy
 Combustion:
is an exothermic process that requires
three components,
 Heat
 oxygen
 suitable fuel.
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9. Mechanisms of flame retardancy
 the combustion temperature, TC,
 At this point, the flammable gases combine with oxygen in
the process called combustion,
 which is a series of gas phase free radical reactions.
 These reactions are highly exothermic
 and produce large amounts of heat and light.
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10. Flame spread
 Heat generated via the burning process sustains the polymer
pyrolysis process.
 Rate of pyrolysis will be accelerating leading to an increased
supply of fuels to the flame which then spreads over the
polymer surface.
 Extent of flame spread also depends on the heat of
combustion of the polymer.
 Greater the heat of combustion, greater the amount of heat
liberated into the flame to sustain the burning cycle.

11. Polymer Flammability
 Four Processes
 Preheating
 Decomposition
 Ignition
 Combustion/ propagation

12. Rate of burning
1.Silk-
 High burning rate.
 Increased by the dyes and other additives to provide color.
2. Cotton & Linen
 High burning rate
 Can be alleviated by the application of flame-retardant chemical additives.

13. Contd..
3. Nylon, Polyester & Acrylic
 Slow to ignite but
 Once ignited, severe melting and dripping occurs.
4. Wool
 Comparatively flame-retardant.
 If ignited, usually has a low burning rate and may self-extinguish.
5. Glass fibers, Nomex & Kevlar
 Almost flame-resistant, designed and manufactured to possess flame-retardant properties.

14. Flame Retardant coating

16. General information on FR
finishes

17. Flame retardation
Smoke & Gaseous Species
Flame “c”
Flammable Volatiles
Oxygen
“b”
Polymer pyrolysis “a”
Heat
“d”
Schematic representation of self-sustaining polymer combustion
cycle.

18. Requirements
 "Soft Touch" finish
 Non-toxic
 Environmental friendly
 Helps reduce residual shrinkage
 Solvent dry cleanable.

19. Important considerations
 Fiber content
 Weave/construction
 Cleaning and care
 Yarn twist
 Certification

20. FIBER CONTENT
1. 100% Natural Fibers
 Best Choice
 Absorbs the flame retardant readily.
 Can be treated to meet the most stringent flammability standards.
2. 100% Synthetic Fibers
 More difficult to treat.
 Non-Absorbent, which causes the chemical to remain on the surface of the fabric.
 Exceptions: Polyester and Rayon
3. Blends
 The more natural the fiber in the blend, better are the results.
 Higher concentrations of synthetic fibers - necessary to add more chemical to meet the
flammability standards.

21. WEAVE / CONSTRUCTION
 looser and lighter weaves burn more rapidly
than tighter and heavier.
 flammability is also affected by the surface
texture.
 Fabrics with long, loose, fluffy pile or "brushed"
nap will ignite more readily than fabrics with a
hard, tight surface.

22. CLEANING AND CARE
 Flame retardant chemicals are water soluble.
 Fabrics should be dry cleaned only in an "uncharged" system containing no water.
 Fabric should be evaluated for flammability after each cleaning. Flame retardant
gets partially or completely removed by washing.
 Damp areas or contact with moisture should be avoided.
 Contact with metal surfaces should be avoided.

23. Yarn twist
 Yarns with a little twist will burn more easily.

24. CERTIFICATION
 Upholstered Furniture Action Council - UFAC
 National Fire Protection Association - NFPA 701
standards
Drapery Fabrics..........NFPA 701, 1989 small scale test
Upholstery Fabrics......NFPA 260 / UFAC class 1
 American Society of Testing and Materials - ASTM

25. Flammability Test

26. 45-degree angle test
 Flammability test for apparels.
 A 2/6 inch dried specimen is
placed at a 45-degree angle and
touched on the surface by a flame
for one second.
 If no ignition occurs, then the
fabric passes.
 It it burns then the rate of burning
determine by the use of a stop
watch.
 Thus, the time of ignition and the
rate of burning determine if the
fabric passes.

27. Flame Proof
Kevlar
Nomex
Glass

28. Kevlar
 Kevlar is the registered
trademark for a light,
strong para-aramid
synthetic fibre.
 It is spun into ropes or fabric sheets.
 Developed at DuPont in 1965 by Stephanie Kwolek and Roberto Berendt.

29. Nomex
 Nomex - registered trademark for flame resistant meta-aramid material
developed in the early 1960s by DuPont.
 An aromatic nylon, the meta variant of the para-aramid Kevlar.
 Sold in both fiber and sheet forms.
 The fibers doesn’t melt, burn, drip or support combustion in air.
 NOMEX® is inherently flame resistant and this property even can’t be
degraded by laundering.
 Not Recommended for use around any molten substances, welding
operations, or in a critical static control application.

30. Application
 Firefighting equipment.
 Race car drivers
 Nomex driving suit & flame-resistant gloves, long underwear, socks and shoes.
 Military pilots and aircrew.
 Thermal Micrometeoroid Garment on the Extravehicular Mobility Unit.
 Thermal blankets on the payload bay doors, fuselage, and upper wing surfaces
of the Space Shuttle Orbiter.
 Protective apparel, electrical insulation or industrial filters.

31. Glass Core Yarn Fabrics
Made with custom engineered
fibreglass core component
yarns.
Offers superior mechanical and functional properties than
100% cotton equivalents.
The functional features can be obtained by varying the core
sheath ratio or with variety of filaments or spun yarn in the
core.

32. Applications
Apparel fabrics
Industrial clothing
Tarpaulins
Tents
Sewing threads

33. Latest Finishes Available

34. PROBAN®
 Used to impart a durable flame retardant treatment to cotton and
other cellulosic fibres and blends.
 Durability is achieved by the formation of a cross-linked inert
polymer within the fibre.
 Since, there is no chemical reaction with the fibre the physical
properties of the base fabrics are largely unaffected.
 The process can be successfully applied to woven or knitted fabrics
across the full range of fabric weights and constructions.
 Application of PROBAN® treated cotton fabrics is in children’s
nightwear.

35. Tyvek® Flame Retardant:
 Tyvek® Flame Retardant is made of pure polyethylene fibres and coated on both sides
with a flame retardant transparent finish.
 Tyvek® Flame Retardant is coated with a harmless phosphorous based finish which, in
the event of fire, minimizes smoke density and toxicity.

36. Siltex 30261/FRC
 Provides a flame retardant finish for cellulosic textiles, durable to repeated
washing and dry cleaning.
 Prevents afterglow
 Can be applied in combination with resins to give easy-care finishes.
 Can be combined with oil and water repellent finishes.
 Can be applied to cellulosic fibres such as cotton, viscose, linen.

37. References
 Chemical finishing of textiles W. D. Schindler and P. J. Hauser.
 www.fibre2fashion.com/industry-article/5/.../flame-retardant-finishes
 www.teonline.com › Knowledge Center › Academic Reports