Valve Vavve ndi valavu yogwiritsidwa ntchito kwambiri, ili ndi maubwino okakamiza kuchuluka, kunenepa kwambiri, ndi zina zambiri pamankhwala, kutetezedwa kwa chilengedwe ndi mafakitale ena. Otsatirawa ndi mbiri ya chitukuko cha mavuvu apulasitiki.
Mu 1950s, mothandizidwa ndi makampani amakampani, kufunikira kwa mavulu pang'onopang'ono. Pakadali pano, zinthu zapulasitiki zagwiritsidwa ntchito kwambiri m'munda wa mafakitale, kotero mainjiniya ena adayamba kuphunzira momwe angagwiritsire ntchito zinthu za pulasitiki popanga mavavu. Makuni apulasitiki oyambilira amapangidwa makamaka pogwiritsa ntchito chlorinyl chloride (pvc) zinthu, zomwe zimatsutsana ndi makina abwino, koma zinthu zake zamakina ndi zosauka komanso zokhala ndi kutentha kochepa.
Mu 1960s, ndikukula kosalekeza kwaukadaulo wa plasticylene (mas), polytetrafluorlene (ptfe) ndi zinthu zina zidagwiritsidwa ntchito popanga mapulogalamu apulasitiki. Zipangizozi zimakhala ndi zinthu zabwinoko zamakina ndi kukana kutukuka, ndipo kumatha kuzolowera malo ogwirira ntchito.
Mu ma 1970, ndikukula kwa mavamu apulasitiki ya pulasitiki, mafilimu ambiri a mafilimu omwe adayambitsidwa, monga mavalo a polyvinyl, mavalo agalasi, ndi njira zabwino, ndipo Sinthani mpaka kovuta kwambiri.
Kumayambiriro kwa zaka za m'ma 2000 zino, ndikudziwitsa anthu chitetezo cha chilengedwe, zofuna za mavuni zikukwera kwambiri. Pakadali pano, zinthu zina za pulasitiki zatsopano zimagwiritsidwa ntchito popanga mavavu, monga polytherketrone (peek), polyimide (pi) ndi zida zina zolimbitsa thupi kwambiri. Zipangizozi zimakhala ndi zinthu zabwinoko zamakina ndi kukana kutukuka, ndipo zimatha kukwaniritsa malo ogwirira ntchito.
Mwachidule, ndikukula kwa makampani amakampani am'manja ndi luso lopitirira muukadaulo wa plastics, mafilimu apulasitiki apanga chitukuko cha pulasitiki zoyambirira za PVC kwa omwe alipo, makina ndi mawonekedwe a Kugwiritsa ntchito, kukhala zida zofunikira komanso zofunikira kwambiri kwa mafakitale a mankhwala, chitetezo choteteza zachilengedwe komanso zachilengedwe.
Post Nthawi: Mar-02-2023