Kevlar. Qhov Mysterious Super Fiber

Poly (p-phenylene terephthalamide), lossis ntau lub npe hu ua Kevlar®, yog lub npe sau npe rau qhov tshwj xeeb sib xyaw ntawm para-aramid hluavtaws fibers. Thaum ua haujlwm rau Lub Tuam Txhab Dupont ™ hauv xyoo 1960, tus kws tshuaj Polish-Asmeskas hu ua Stephanie Kwolek tau ua haujlwm los tsim lub teeb yuag tshiab uas tsim los hloov cov hlau loj loj siv hauv tsheb log tsheb thaum lub sijhawm qaum. Koj pom, rov qab rau xyoo 1964, cov roj av tsis txaus ntawm lub xyoo 70s tau kwv yees los tsim kev thov rau cov tsheb siv roj ntau dua. Los ntawm kev sib koom ua ke ib qho tshwj xeeb polymer formulation, Kwolek pom cov kua muaju uas tsim nyob rau hauv cov tshuaj "kua zaub." Thaum xub thawj, qhov kev daws teeb meem tsis zoo heev, tab sis nws ua siab ntev, thiab tom qab kev sim ntxiv pom tias thaum cov tshuaj tau muab tso rau hauv "spinneret," nws tsim cov fibers uas tsis tawg.

Xav tias koj tuaj yeem hais tias Stephanie yog leej niam ntawm kev tsim khoom. OK

Kevlar yog tiag tiag tsuas yog ib tug khawv koob version ntawm yas. Txawm li cas los xij, tsis yog yas zoo li lub pob tawb. Vim lawv cov qauv tshuaj tshwj xeeb thiab kev sib txuas ntev ntev molecular, ultra-tight knitted fibers muaj cov khoom uas tso cai rau lawv nres cov mos txwv thaum woven rau hauv nplooj ntawv thiab tua cov xub ncaj thiab tsom thaum woven rau hauv strands.

Kevlar tsuas yog muaj thiab tsim los ntawm Dupont, thiab muaj feem xyuam rau lwm cov fibers xws li Nomex thiab nylon li niaj zaus, ob qho tib si kuj tsim los ntawm Dupont. Muaj ntau hom Kevlar sib xyaw kom tau raws li cov cai tshwj xeeb thiab tshwj xeeb. Kevlar 29 thiab Kevlar 49 sawv cev rau ob qho kev siv fiber ntau. Cov ntawv thov rau Kevlar 49 fabrics suav nrog: kayaks, canoes, nkoj siab ceev, dav hlau vaj huam sib luag, cov khoom ua si thiab cua turbines. Kevlar 49 npuag yuav tsum yog ib qho sib xyaw ua ke kom ua kom nws lub cev muaj zog. Qhov no tshem tawm kev siv rau hauv daim ntaub qhuav xws li khaub ncaws lossis lub cev mos mos. Kevlar 29 ntaub yog tsim los ntawm cov xov tawv tawv tsim los tiv thaiv ballistic. Cov qib ballistic nyob ntawm ntau yam kev sim: hom riam phom, caliber, hom mos txwv, xeem ntau yam, thiab qhov projectile tshaj tawm.

Kevlar cov khoom pab kom nws sib nrug los ntawm ntau lwm cov fibers thiab cov ntaub ntawv. Kevlar muaj zog tab sis kuj yog lub teeb heev. Kevlar fibers muaj ntau tshaj yim npaug ntawm lub zog tensile ntawm steel hlau. Nws kuj ua haujlwm kub zoo thiab tuaj yeem tiv taus qhov kub siab tshaj 850ºF. Kevlar yuav hlawv, tab sis yog yooj yim extinguished los ntawm kev tshem tawm cov cua sov qhov chaw. Kevlar muaj peev xwm nyob twj ywm mos thiab pliable mus rau -320ºF. Thiab txawm tias muaj zog me ntsis ntawm qhov kub thiab txias. Zoo li txhua tus superhero, Kevlar muaj nws qhov tsis muaj zog. Kev raug UV ntev ntev tuaj yeem ua rau nws cov fibers tsis muaj xim thiab degrade. Tsis tas li ntawd, qee yam tshuaj ntawm fiber ntau tuaj yeem ua rau nws tsis muaj zog.

Kevlar feem ntau ua ke nrog ntau yam khoom siv los tsim ntau yam khoom sib xyaw. Kev sib xyaw ua ke nrov suav nrog Kevlar nrog carbon fiber thiab Kevlar nrog cov ntaub ntawv stretch xws li Lycra. Cov xim daj pom tau ntawm Kevlar yog nws cov xim ntuj. Nws tsis tuaj yeem bleached, tab sis nws tuaj yeem dyed hauv cov xim xws li liab lossis xiav.