Mitengo yachilengedwe ndi zitsulo zakhala zofunikira zomangira anthu kwa zaka zikwi zambiri.Ma polima opangidwa omwe timawatcha kuti mapulasitiki ndi zinthu zaposachedwa zomwe zidaphulika m'zaka za zana la 20.
Zitsulo zonse ndi mapulasitiki zili ndi zinthu zomwe zimayenera kugwiritsidwa ntchito m'mafakitale ndi malonda.Zitsulo ndi zamphamvu, zolimba, ndipo nthawi zambiri zimakhala zolimba ku mpweya, madzi, kutentha, ndi kupsinjika maganizo nthawi zonse. zida zomangika zoopsa: zida za pulasitiki sizinthu zabwino, ndipo palibe amene akufuna kukhala m'nyumba yapulasitiki.Kuonjezera apo, nthawi zambiri amayengedwa ndi mafuta oyaka.
M'zinthu zina, matabwa achilengedwe amatha kupikisana ndi zitsulo ndi mapulasitiki.Nyumba zambiri za mabanja zimamangidwa pamatabwa.Vuto ndiloti matabwa achilengedwe ndi ofewa kwambiri ndipo amatha kuwonongeka mosavuta ndi madzi kuti alowe m'malo mwa pulasitiki ndi zitsulo nthawi zambiri.Pepala laposachedwa lofalitsidwa m'magazini ya Matter likufufuza kupangidwa kwa zinthu zamatabwa zolimba zomwe zimagonjetsa izi.
The fibrous dongosolo la nkhuni tichipeza pafupifupi 50% mapadi, ndi polima zachilengedwe ndi theoretically zabwino mphamvu properties.The theka lotsala la matabwa dongosolo makamaka lignin ndi hemicellulose.Ngakhale mapadi mitundu yaitali, ulusi wolimba kuti kupereka nkhuni ndi msana wa mphamvu zake zachilengedwe, hemicellulose ali pang'ono mogwirizana dongosolo ndipo motero amathandiza kanthu kwa matabwa ulusi wodzaza ndi matabwa. Koma pofuna kulumikiza matabwa ndi kumanga ulusi wa cellulose, lignin inakhala cholepheretsa.
Mu phunziro ili, nkhuni zachilengedwe zinapangidwa kukhala matabwa olimba (HW) mu masitepe anayi.Choyamba, nkhunizo zimaphika mu sodium hydroxide ndi sodium sulfate kuchotsa ena a hemicellulose ndi lignin.Pambuyo pa mankhwalawa mankhwala, nkhuni zimakhala zowawa kwambiri mwa kukanikiza mu makina osindikizira kwa maola angapo kutentha. matabwa amapanikizidwa pa 105 ° C (221 ° F) kwa maola angapo kuti amalize kachulukidwe, ndiyeno amawuma.Potsirizira pake, nkhunizo zimamizidwa mu mafuta amchere kwa maola 48 kuti mankhwala omalizidwawo asalowe madzi.
Mmodzi wamakina katundu wa zinthu structural ndi indentation kuuma, umene ndi muyeso wa mphamvu yake kukana mapindikidwe akamapindidwa ndi mphamvu.Diamond ndi wolimba kuposa chitsulo, cholimba kuposa golide, cholimba kuposa matabwa, ndi zovuta kunyamula thovu.Pakati pa mayesero ambiri umisiri ntchito kudziwa kuuma, monga Mohs kuuma ntchito mu gemology, mmodzi wa Brinell zitsulo ndi mayeso osavuta: I ball ndi kuyesa zitsulo. kukanikizidwa mu mayeso pamwamba ndi mphamvu inayake.Yesani m'mimba mwake wa indentation zozungulira analengedwa ndi mpira.The Brinell kuuma mtengo mawerengedwe ntchito masamu chilinganizo; kunena mosapita m'mbali, bowo lomwe mpira umagunda kwambiri, ndiye kuti zinthuzo zimakhala zofewa. Pachiyeso ichi, HW imakhala yolimba ka 23 kuposa nkhuni zachilengedwe.
Mitengo yambiri yachilengedwe yosasamalidwa idzayamwa madzi.Izi zimatha kukulitsa nkhuni ndipo potsirizira pake zimawononga mapangidwe ake.Olembawo adagwiritsa ntchito mchere wa masiku awiri kuti awonjezere kukana kwa madzi a HW, kupangitsa kuti hydrophobic ("kuopa madzi").Kuyesa kwa hydrophobicity kumaphatikizapo kuika dontho la madzi pamtunda.Pamene hydrophobic yambiri imakhala pamwamba, madontho amadzimadzi amadzimadzi amakhala ochepa kwambiri. ("okonda madzi") pamwamba, kumbali ina, amafalitsa madontho pansi (ndipo kenako amamwa madzi mosavuta) .Choncho, mchere wothira mchere sikuti umangowonjezera kwambiri hydrophobicity ya HW, komanso umalepheretsa nkhuni kuti zisatenge chinyezi.
M'mayesero ena a uinjiniya, mipeni ya HW idachita bwino pang'ono kuposa mipeni yachitsulo.Olembawo amati mpeni wa HW ndi wakuthwa kuwirikiza katatu ngati mpeni wopezeka pazamalonda.Komabe, pali chenjezo ku zotsatira zochititsa chidwi izi.Ofufuza akuyerekeza mipeni ya tebulo, kapena zomwe tingatchule mipeni ya batala.Izi sizikutanthauza kuti zikhale zakuthwa kwambiri chifukwa chachikulu cha steak. mwina kudula nyama yomweyo ndi mbali yosaoneka bwino ya foloko yachitsulo, ndipo mpeni ukhoza kugwira ntchito bwino kwambiri.
Nanga misomali?Msomali umodzi wa HW mwachiwonekere umakhomeredwa mosavuta mu mulu wa matabwa atatu, ngakhale osati mwatsatanetsatane monga momwe ulili wosavuta poyerekeza ndi misomali yachitsulo. Zikhomo zamatabwa zimatha kugwira matabwa pamodzi, kukana mphamvu yomwe ingawang'ambe, ndi kulimba kofanana ndi zikhomo zachitsulo.
Kodi misomali ya HW ili bwino m'njira zina? Zikhomo zamatabwa zimakhala zopepuka, koma kulemera kwake sikumayendetsedwa ndi unyinji wa zikhomo zomwe zimaigwirizanitsa pamodzi. Zikhomo zamatabwa sizidzachita dzimbiri.
Palibe kukayikira kuti wolembayo wapanga njira yopangira matabwa amphamvu kuposa matabwa achilengedwe.Komabe, kugwiritsidwa ntchito kwa hardware kwa ntchito ina iliyonse kumafuna kuphunzira kowonjezereka.Kodi zingakhale zotsika mtengo komanso zopanda zinthu monga pulasitiki?Kodi zingathe kupikisana ndi zinthu zachitsulo zamphamvu, zowoneka bwino, zosatha?
Nthawi yotumiza: Apr-13-2022
