Mary Allen
Mphira umapezeka mumadzi a mtengo wapadera. Labala angagwiritsidwe ntchito kupanga mphira wofufutira, malaya amvula ndi nsapato za rabara, matayala agalimoto, ndi zina zambiri. Dzina la rabara limachokera ku chilankhulo cha India: "Cao" amatanthauza mtengo, "Ochu" amatanthauza kung'amba.
Mtengo wa rabara poyamba umachokera ku dera la Amazon ku South America. Amafika kutalika kwapakati. Pansi pa khungwa, ili ndi machubu a mkaka omwe amanyamula kuyamwa kuchokera kumizu kupita kumasamba. Madzi awa ndi magawo awiri mwa magawo atatu a madzi ndi gawo limodzi mwa magawo atatu a mphira.
Amwenye anali atazindikira kale kuti mukhoza kudula theka la thunthu ndi oblique odulidwa ndi kupachika chidebe chaching'ono pamtengo, ndipo kuyamwa kumagwera mmenemo. Ngati simudula mbali ina ya mtengo, mtengowo ukhoza kukhalabe.
Madzi amkaka amatchedwanso "rabala wachilengedwe" kapena "latex". Ngati mukulitsa madziwo, mutha kugwiritsa ntchito kuvala nsalu kapena chikopa. Izi zimapangitsa kuti zisalowe madzi.
Kodi mungapange chiyani kuchokera ku rabara?
Mtengo wa rabara unafalikira pakapita nthawi yaitali atapezeka ku America. Masiku ano imapezeka m’minda ya padziko lonse, koma m’kadera kotentha kokha kumbali zonse za equator. Izi zisanachitike, phula lokhalo linkadziwika kuti limapanga nsalu kuti zisalowe madzi. Zinali bwino kwambiri ndi labala.
Mu 1839, Charles Goodyear wa ku America anapambana kupanga mphira kuchokera ku mphira wachilengedwe. Njirayi imatchedwa vulcanization. Labala ndi lolimba kwambiri kuposa mphira wachilengedwe. Mukhozanso kuzisiya zofewa kapena kuzilimbitsa. Ndiwoyeneranso matayala agalimoto, mwachitsanzo.
Mu 1900, Ivan Kondakov wa ku Russia anakwanitsa kupanga mphira mwachinyengo. Mukhozanso kupanga mphira kuchokera pamenepo. Masiku ano, pafupifupi gawo limodzi mwa magawo atatu a mphira amachokera ku chilengedwe, ndipo magawo awiri pa atatu aliwonse amapangidwa mongopanga, makamaka kuchokera ku mafuta ofunikira.
Masiku ano, oposa theka la mphira amagwiritsidwa ntchito popanga matayala agalimoto. Chimodzi mwazinthu zazikulu kwambiri masiku ano chimatchedwabe dzina la woyambitsa wake ndipo chimatchedwa Goodyear. Mwaye wochokera ku chimney umawonjezedwa ku mphira panthawi yopanga. Izi zimapangitsa kuti matayala azikhala olimba komanso amawapatsa mtundu wakuda. Gawo laling'ono ndilofunika pa nsapato za rabara, nsapato za nsapato, zovala zodzitetezera zapadera, mphira, zofufutira, magolovesi, makondomu, ndi zina zambiri.