Ukufakwa kwamapayipi e-PVC (Polyvinyl Chloride) kutholakala kakhulu kwingqalasizinda yesimanje, kufaka phakathi amapayipi, amanzi angcolile, ukuhlinzekwa kwamanzi, kanye nokuthuthwa koketshezi lwezimboni. Ukuthandwa kwawo kuvela ezinzuzweni ezingokwemvelo: ukumelana namakhemikhali, ukusebenza kahle kwezindleko, kanye nokuqina kwesakhiwo. Kodwa-ke, isakhiwo sama-molecule se-PVC—esibonakala ngamayunithi e-vinyl chloride aphindaphindayo—senza kube lula ukuwohloka ngaphansi kokucindezeleka kokushisa, i-oxidative, kanye ne-UV. Yilapho-keIziqinisi ze-PVCzidlala indima ebalulekile: zinciphisa ukuwohloka, ziqinisekisa ukuthi ukufakwa kwamapayipi kugcina ubuqotho bomshini kanye nokusebenza phakathi nesikhathi sazo sokusebenza. Ngezansi ukuhlaziywa okuningiliziwe kwezicelo zazo, izindlela, kanye nezindlela zokukhetha ezinhlelweni zamapayipi e-PVC.
1. KunganiYenza i-PVCUkufakwa Kwamapayipi Kudinga Iziqinisi
I-PVC idlula ekuwohlokeni okungenakuguqulwa lapho ivezwa emazingeni okushisa aphezulu (okuvamile ezinqubweni zokukhipha noma zokubumba ngomjovo) noma ukucindezeleka kwemvelo okuhlala isikhathi eside (isb., ukukhanya kwelanga, umswakama, noma ukuchayeka kumakhemikhali). Indlela eyinhloko yokuwohloka iwukuncishiswa kwe-hydrochlorination: ukushisa noma amandla e-UV aphula izibopho ze-C-Cl ezibuthakathaka, akhulule i-hydrochloric acid (HCl) futhi aqale ukusabela kweketanga okuholela ekuqhekekeni kweketanga le-polymer. Lokhu kubonakala kanje:
• Ukushintsha kombala (ukuba phuzi noma ukuba nsundu)
• Ukulahlekelwa amandla okushaya kanye nokuguquguquka
• Ukuqhekeka noma ukuqhekeka, okubeka engcupheni ukumelana nokuvuza
• Ukungcoliswa koketshezi oluthuthwayo (okubalulekile ezinhlelweni zamanzi aphuzwayo)
Iziqinisi ziphazamisa le nqubo, zizenze zibe yinto ebalulekile ekukhiqizweni kwamapayipi e-PVC.
2. Izindlela Zokuqinisa Ama-PVC Kumapayipi Okufakwayo
Izinzisi zisebenza ngezindlela eziningi ezisebenzisanayo ukuvikela i-PVC:
•Ukususa i-HCl:Nciphisa i-hydrochloric acid ekhishwe, uyivimbele ekubangeleni ukuwohloka okuqhubekayo.
•Ukuvinjelwa Okukhulu Kwamahhala:Qeda ukusabela kweketanga okuqalwa ukushisa noma ama-free radical akhiqizwa yi-UV.
•Ukuthathwa Kwe-Ion Yensimbi:Bopha ukungcola kwensimbi okumbalwa (isb. insimbi, ithusi) okusheshisa ukuwohloka.
•UVUkuvikela:Bonisa noma umunce imisebe ye-UV, ebalulekile ekusetshenzisweni kwamapayipi angaphandle (isb., ukudonsa amanzi ngaphezu komhlabathi).
•Usizo Lokugcoba:Ezinye izinto eziqinisayo (isib., izinto eziqinisayo ze-UV), i-calcium stearate zinciphisa ukungqubuzana ngesikhathi sokucubungula, zivimbele ukushisa ngokweqile.
3. Izinhlobo Zeziqinisi Ezisetshenziswa Kumapayipi E-PVC
Ukukhetha isiqinisi kuncike ezimweni zokucubungula, izidingo zokusetshenziswa kokugcina, kanye nokuhambisana nemithetho. Izinhlobo ezivamile zifaka:
4. Izindlela Zokukhetha Ezibalulekile Zokufaka Amapayipi
Uma kucaciswa iziqinisi zokufakwa kwamapayipi e-PVC, abakhiqizi kumele bacabangele:
•Amapharamitha Okucubungula:Izinga lokushisa lokukhipha/lokubumba (160–200°C kumapayipi) kanye nezikhathi zokuhlala zilawula ukuzinza kokushisa okudingekayo. Izinqubo zokushisa okuphezulu (isb., amapayipi amanzi ashisayo) zidinga iziqinisi ezinokumelana nokushisa okuqinile (isb., i-organotin).
•Indawo Yokusetshenziswa Kokugcina:Amapayipi amanzi aphuzwayo adinga isitifiketi se-NSF/ANSI 61 noma i-WRAS, okuphakamisaI-Ca-Znnoma iziqinisi ze-organotin. Amapayipi angaphandle adinga iziqinisi ze-UV isib., iziqinisi zokukhanya kwe-amine ezivinjiwe (HALS).
•Ukuthobela Imithetho:Imikhawulo yomhlaba wonke yezinsimbi ezisindayo (i-Pb, i-Cd) isunduzela imboni ezindleleni ezingasetshenziswa njengezinto ezinobungani nemvelo (i-Ca-Zn, iziqinisi ezisekelwe ezintweni eziphilayo).
•Izindleko vs. Ukusebenza:Nakuba iziqinisi ezisekelwe kumthofu zishibhile, izindleko zesikhathi eside (isb. izinhlawulo zomthetho, izinselele zokuvuselela kabusha) zisekela izinketho eziqhubekayo.
5. Izitayela Ezivelayo Kubuchwepheshe Bokuzinza
Njengoba imithethonqubo yezemvelo iqina futhi ukusimama kuthola ukubaluleka, imboni yamapayipi e-PVC iyashintsha iye ku:
•Izinhlelo ze-Ca-Zn Ezisebenza Kakhulu:Kuthuthukiswe ngama-co-stabilizers (isb., ama-polyol, ama-zeolite) ukuze kufane nokusebenza kokushisa kwezinye izindlela ezisekelwe ku-lead.
•Iziqinisi Ezinemisebenzi Eminingi:Ukuhlanganisa ukuzinza kokushisa, ukumelana ne-UV, kanye nokugcotshwa kwesithasiselo esisodwa ukuze kube lula ukwenza amafomula.
•Iziqinisi Ezisekelwe Ku-Bio:Kuthathwe ezinsizeni ezivuselelekayo (isb., ama-ester asekelwe ezitshalweni), okuhambisana nemigomo yomnotho ojikelezayo.
Iziqinisi ze-PVCziyisisekelo sokusebenza kanye nobude besikhathi sezinto zokufakelwa kwamapayipi e-PVC, okuvumela ukusetshenziswa kwazo okuphephile nokuthembekile kuzo zonke ingqalasizinda ezibalulekile. Kusukela ekuvimbeleni ukuwohloka ngesikhathi sokukhiqiza kuya ekuqinisekiseni amashumi eminyaka yenkonzo ezindaweni ezinzima, indima yazo ayinakushintshwa. Njengoba imboni ithuthuka, ukugxila ezintweni zokuqinisa ezinobuthi obuphansi, ezisebenza kahle kakhulu—ikakhulukazi i-calcium-zinc complexes—kuzoqhuba ukusungula izinto ezintsha, kulinganisela ukusebenza kanye nomthwalo wemfanelo wezemvelo. Konjiniyela nabakhiqizi, ukukhetha isiqinisekisi esifanele akuyona nje ukukhetha kobuchwepheshe kodwa ukuzibophezela ekuqineni, ukuphepha, kanye nokuhambisana nemithetho.
Isikhathi sokuthunyelwe: Septhemba-02-2025