NYLON Fiber processing 1.doc.pdf

Nylon is the most useful synthetic material with applications varying from daily life activities to industries. The term nylon points towards a polymer family known as linear polyamides.

1. DONGHUA UNIVERSITY
BetemariamLimenewu
MyChineseName isGe liming
Ethiopia
Textile Engineering (Masters)
ID No: 320023
Nylon fiberProcessing

2. Outline of presentation
•Introduction
•Difference between nylon 6 & 6,6
•Manufacturing process of Nylon 6 & 6, 6 fiber
•Properties of Nylon fiber
•Application of Nylon fiber

3. Introduction
Nylonisthemostusefulsyntheticmaterialwithapplications
varyingfromdailylifeactivitiestoindustries.Thetermnylon
pointstowardsapolymerfamilyknownaslinearpolyamides.
Therearetwoapproachestomakingnylonforfibre
applications.Inthefirstapproach,themoleculesthatconsistof
anacidicgroup(COOH)oneveryendreactwithmolecules
thatcontainamino(NH
2)groupsateachend.

4. Conti…
Nylonismadebyaprocesscalledpolymerization(condensation
polymerizationreaction),inwhichindividualshortmoleculesform
long-chainmacromoleculeswithhighrelativemolecularmass.Inthe
processofmakingNylonfibersgiantchainlikepolymersformamide
groupswhichthengoontoformstronghydrogenbonds.These
hydrogenbondsholdtheadjacentchainstogetherandtheresultantfiber
isanexceptionallystrongNylonfiber.

5. Difference between Nylon 6 & 6, 6
i. Nylon 6
Nylon6ismadebyheatingcaprolactamtoabout250
o
Cwithabout5-
10%waterthrownin.Nylon6isonlymadefromonekindofmonomer,a
monomercalledcaprolactam.Nylon6,6ismadefromtwomonomers,
adipoylchlorideandhexamethylenediamine.

6. ii. Nylon 6, 6
Nylon6,6isalinearcondensationpolymermadefromhexamethylene
diamineandadipicacid.Specificamountsofthetwochemicalsare
combinedinsolutiontoformnylonsalt.Thissaltispurified,polymerized,
extrudedinribbonform,andchippedintosmallflakesorpellets.These
flakesorpelletsaremeltedandextrudedthroughaspinneretintocoolair
andthenylonfilamentsareformed.

7. Conti..
•Nylon 6,6, polyamide Condensation product of aliphatic
diamine with aliphatic diacid.
Polymer 3D model of Nylon6,6

8. Conti.
•Nylon6structureisderivedfromonemonomer,which
isamoleculethatcanbebondedtootheridentical
moleculestoformpolymers.Thenylon6monomerhas
sixcarbonatoms,hencethenamenylon6.
•Nylon6/6structureismadefromtwomonomers.Each
ofthesemonomershassixcarbonatoms,whichis
reflectedinthenamenylon6/6.

9. Nylon fiber Manufacturing Process
Adipicacid,hexamethylenediamine,andwaterareadded
toareactionvesseltoformHexamethyleneDiammonium
Adipate,commonknownas“Nylonsalt”solution.After
evaporation,watercontinuestoberemovedfromthe“salt
solution”.Thenylonpolymeristhenextrudedthrough
spinneretsorpelletized.
AslurryofTIO2pigmentsandwater,usedtodelusterfibers,
isaddedtotheNylonsalt.Polymerizationbeginsinthe
reactorwherepolyhexamethylene adipamide,(Nylon66),is
formed.TheNylonpolymeristhenextrudedthrough
spinneretsorpelletized.

10. Conti..
Nylon fibermanufacturing process

11. Spinning process of Nylon fiber
Thespinningofnylon6isdonebyusingthe“melt
spinning”process.Inthisprocess,thepolymergetsmeltedunder
exclusionofairatatemperatureof250°C-270°C(30°C-50°Cmore
thanthemeltingpoint).Foraveryhomogenousmeltingprocess,the
polymerismeltedinanextruder.Thehotandmoltenpolymerisfed
tothespinneretswiththehelpofafeedingpumpandextruder.This
moltenpolymerpassesthroughverysmallholesofspinnerets.“Thus
thenylon6filamentisformed”.
Onthelowerpartofthespinneret,thefilamentsareenteredthe
quenchduct.Thisisapartof2-4metreswherethestillhotfilaments
arequenchedwithair.Itisveryimportanttokeeptheairflowvery
gentleandstabletoavoidthefilamentsstickingtogether.

12. Manufacturing nylon fibers and nylon yarns, as
explained in the following:
•Polycondensation
This is a chemical process to produce the nylon polymer
using caprolactumand acetic acid.
•Chipping
The nylon rope produced from the polymerization process is
cut into chips.

13. Conti..
•Melting
In this stage nylon chips are melted to reach the viscosity suitable
for pumping to the spinning process.
•Spinning
In this process, molten nylon is pumped to spinnerettes, and the
polymer streams coming out are cooled by blown air that let the
polymer solidifies and form continuous nylon filament.

14. Properties of Nylon fiber
•Shape:Shape is controlled by the manufacturer, filaments are uniform and
long.
•Luster: Bright to Dull
•Elastic Recovery: 100%
•Elongation: Good
•Resiliency: Good
•Density: 1.1 g / ccm
•Moisture absorption: 8%

15. Conti…
•Dimensional stability: Excellent
•Acids: resistance is poor
•Alkalies: Good resistance
•Sun light: Generally affects
•Insects: Normally damages
•To flame: Self extinguishing

16. Application of Nylon Fiber