Thawj cov ntaub ntawv siv los ntawm tib neeg rau lub tsheb nres yog cov khoom siv ntuj xws li ntoo thiab tawv.
Vim tias qhov ceev ceev ntawm lub sijhawm ntawd, qhov kub thiab txias tsim los ntawm cov brakes kuj tseem qis heev. Txog rau xyoo 1897, cov neeg Askiv thawj zaug tau tsim ib qhonres nruaszoo ib yam li niaj hnub no, thiab tsim ib txoj hlua khi ua los ntawm cov plaub hau lossis paj rwb ua cov khoom tseem ceeb. Asphalt soaked. Cov khoom siv no tau siv tsis yog rau lub tsheb thauj khoom thaum lub sijhawm tab sis kuj tseem siv rau lub tsheb thaum ntxov.
Ntuj fibers xws li paj rwb yuav dhau los ua carbon ntawm 270 degree C thiab poob nws cov khoom sib txhuam thiab lub zog, yog li txwv tsis pub siv.
Xyoo 1908, qhov txhab asbestoskev sib txhuam hauv ob sab phlutau tsim. Cov ntaub ntawv sib txhuam asbestos tau yog cov khoom tseem ceeb rau cov khoom siv nres kom txog rau thaum xyoo 1960s. Raws li kev faib tawm, kev txhim kho ntawm cov ntaub ntawv sib txhuam txhuam tau dhau los ntawm cov theem hauv qab no:
Ua ntej xyoo 1930, txoj hauv kev tseem ceeb yog siv asbestos ntev fiber ntau thiab lwm hom hlau (xws li tooj dag hlau). Cov khoom siv impregnating tau hloov zuj zus los ntawm bitumen mus rau kev sib xyaw ntawm cov roj thiab cov kua nplaum thiab pib hloov cov fibers ntev nrog luv fibers. Nyob rau theem tom ntej, muaj cov txheej txheem ntawm kev sib tov qhuav kub nias yam tsis muaj kev npaj. Nyob rau xyoo 1930, cov kws kho mob tau tsim cov ntaub ntawv hloov tau yooj yim nrog cov thermal stability zoo dua. Qhov no ua rau cov txheej txheem qhuav tuaj yeem nrog ntau cov khoom ntim thiab maj mam txhim kho lub nruas nres peb paub niaj hnub no.
Asbestos yog cov khoom siv tseem ceeb rau 30 xyoo tom ntej. Nyob rau tib lub sijhawm, cov txiaj ntsig kev tshawb fawb ntawm kev lag luam roj hmab kuj tau txhawb kev txhim kho cov txheej txheem kev sib txhuam. Kev npaj txheej yog txhuam nrog cov roj hmab sib tov kua nplaum, thiab tom qab ntawd folded los yog stacked rau kub xovxwm, uas yog tseem dav siv niaj hnub no.
Xyoo 1950, SKWELLMAN ntawm Tebchaws Meskas thawj zaug tsim cov khoom sib txhuam ua los ntawm cov hmoov hlau, graphite thiab lwm cov khoom ntim thiab cov resin los ua cov ntawv khi, uas yog hu ua cov khoom sib txhuam semi-metallic.
Xyoo 1970, cov khoom siv no tau siv rau hauv discnres tshebthiab tseem tau txais dav dav niaj hnub no. Ib tug loj tus naj npawb ntawm ib nrab hlau nres nres tseem nyob hauv kev lag luam thoob ntiaj teb.
Txij li thaum xyoo 1960, nrog kev txhim kho txuas ntxiv ntawm kev tsim tsheb, cov kev xav tau ntawm cov brakes tau nce siab dua, yuam ntau lub tuam txhab kev sib txhuam cov ntaub ntawv los kawm txog kev sib raug zoo ntawm cov ntaub ntawv sib txhuam thiab nres nruas / disc, thiab nrhiav lwm cov ntaub ntawv rau asbestos. Tom qab kev soj ntsuam, tib neeg paub tias kev siv cov asbestos yog raug rau ntau yam kev txwv. Asbestos cov peev txheej raug txwv, thiab qhov zoo ntawm asbestos sib txawv heev, tshwj xeeb tshaj yog asbestos muaj kev cuam tshuam ntau dua rau tib neeg kev noj qab haus huv thiab ib puag ncig.
Lub hav zoov ntawm cov teeb meem no tau txhawb cov txheej txheem ntawm kev hloov cov asbestos nrog iav fiber ntau, ntxhia fiber ntau thiab hlau fiber ntau. Tsis ntev los no, ntau thiab ntau aramid fiber ntau, potassium titanate whisker thiab hluavtaws fiber ntau tau siv.
Tam sim no lub automaker qhov yuav tsum tau rau lub nres nres yog: kov yeej cov shortcomings ntawm semi-metallic nres ncoo; txo thermal conductivity; txo thermal expansion; tsim cov ntaub ntawv tshiab uas tswj cov kev sib txhuam ntawm qhov kub thiab txias; Txo qhov hnav ntawm dual; tsim cov ntaub ntawv sib txhuam haum rau aluminium brake discs.
Nyob rau hauv xyoo tas los no, kev vam meej ntawm Japanese ceramic kev sib txhuam cov ntaub ntawv tau txhawb txoj kev loj hlob sai ntawm cov ntaub ntawv sib txhuam. Nres pads siv cov ntaub ntawv ceramic tau pib daws qhov teeb meem tseem ceeb xws li thermal conduction, thermal expansion thiab qhov txhab disc, thiab tuaj yeem tuav cov yam ntxwv ntawm kev sib txhuam hauv qhov kub thiab txias.
Niaj hnub no, ntau thiab ntau automakers thiab aftermarkets yog pib siv nyob rau hauv loj tus xov tooj, thiab cov kev ua lag luam qhia tau sai heev.
