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Polyamidefibers

(commonlyknownasnylon)

Thesefibersofferexcellentcharacteristicsforrope,asthey

combinestrength andelasticity, enabling them toabsorb

shockloadsbetterthananyothermaterial.Theydonotrotor

float.Thefiberscanbemodifiedchemicallytoproduceother

productswhichvaryslightlyfromoneanother(nylon6,nylon

66,andnylon 11 ) andareusedin climbingrope.Fishinglineis

alsomadeofpolyamidefibers,asithastobebothtoughand

flexibleandmustallowknotstobemadein it andtoholdwell.

Polyesterfibers

Polyesterfibershavethebestmechanicalqualitiescombined

withlowelasticityandsoarea goodchoiceforropetobeused

insailing.Theyarehighlyresistanttowearandatmospheric

agentsandcanbepre-stretchedtoreducedeformationunder

strain.Theydonotfloat.

Polyethylenefibers

Ropesmadeofpolyethylenefibersshouldbeavoided.They

areverycheap,buttheyarenotverystrong,andtheystretch

andslipeasily,sotheydonotholda knotwell.Addedtothisis

thefactthattheyaredifficulttohandle.Theyare,however,

veryresistanttoatmosphericagentsand alsofloat.Theyare

usedforlifelinesonrowboatsandrafts,astowropesforwater

skiing,andasrescuelines.

Aramidfibers

Thesearethenewestofthesyntheticfibersusedforropes.
TheyaremanufacturedbyDupontunderthenameKevlar.The

producthascharacteristics whichare morecomparableto

thoseofsteelthantothecommonsyntheticfibers.In fact,this

material does notmelt. but decomposes at about 500°C

(932°F)andhasa breakingstrainequaltothatofsteelofthe

samesection,althoughitisslightlymoreelastic.Itisnotvery

resistanttolightanddoesnotfloat. Itisusedtoa limited

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