Chikopa chopangidwa ndi PVC (PVC-AL) chikadali chinthu chofunikira kwambiri m'magalimoto, zovala zamkati, ndi nsalu zamafakitale chifukwa cha mtengo wake wokwanira, kuthekera kwake kokonza, komanso kusinthasintha kwake. Komabe, njira yake yopangira zinthu imakumana ndi zovuta zaukadaulo zomwe zimachokera ku mphamvu ya mankhwala ya polima - zovuta zomwe zimakhudza mwachindunji magwiridwe antchito azinthu, kutsatira malamulo, komanso magwiridwe antchito opangira.
Kuwonongeka kwa Kutentha: Cholepheretsa Chofunikira Kwambiri Chogwirira Ntchito
Kusakhazikika kwa PVC pa kutentha kwanthawi zonse (160–200°C) kumabweretsa vuto lalikulu. Polima imadutsa mu dehydrochlorination (HCl excretion) kudzera mu self-catalyzed chain reaction, zomwe zimapangitsa kuti pakhale mavuto atatu:
• Kusokonezeka kwa njira:HCl yotulutsidwa imawononga zida zachitsulo (zopangira ma calender, zophimba) ndipo zimayambitsa kufalikira kwa PVC matrix, zomwe zimapangitsa kuti pakhale zolakwika monga matuza pamwamba kapena makulidwe osafanana.
• Kusintha kwa mtundu wa chinthu:Ma polyene ophatikizika omwe amapangidwa panthawi yowonongeka amapereka chikasu kapena bulauni, zomwe sizikwaniritsa miyezo yokhazikika ya utoto pakugwiritsa ntchito kwapamwamba.
• Kutayika kwa katundu wa makina:Kudula unyolo kumafooketsa ukonde wa polima, zomwe zimachepetsa mphamvu yokoka ya chikopa chomalizidwa komanso kukana kung'ambika ndi 30% pazochitika zoopsa.
Kukakamiza Kutsatira Malamulo ndi Zachilengedwe
Kupanga kwa PVC-AL kwachikhalidwe kukuyang'aniridwa kwambiri motsatira malamulo apadziko lonse lapansi (monga EU REACH, miyezo ya US EPA VOC):
• Utsi wa volatile organic compound (VOC):Kuwonongeka kwa kutentha ndi kulowetsedwa kwa pulasitiki pogwiritsa ntchito zosungunulira kumatulutsa ma VOC (monga zotumphukira za phthalate) zomwe zimaposa malire a mpweya wotuluka.
• Zotsalira zachitsulo cholemera:Machitidwe okhazikika akale (monga lead, cadmium-based) amasiya zodetsa, zomwe zimapangitsa kuti zinthu zisayenerere kuvomerezedwa ndi eco-label (monga OEKO-TEX® 100).
• Kubwezeretsanso kwa moyo wonse:PVC yosakhazikika imawonongeka kwambiri panthawi yobwezeretsanso zinthu pogwiritsa ntchito makina, zomwe zimapangitsa kuti pakhale poizoni wotulutsa madzi ndikuchepetsa ubwino wa chakudya chobwezerezedwanso.
Kulimba Koipa Mu Mikhalidwe Yogwirira Ntchito
Ngakhale PVC-AL yosakhazikika ikapangidwa, imakalamba mofulumira:
• Kuwonongeka kwa UV:Kuwala kwa dzuwa kumayambitsa kupangika kwa kuwala kwa dzuwa, kuswa maunyolo a polima ndikupangitsa kuti chivundikirocho chikhale cholimba—chofunika kwambiri pa mipando yamagalimoto kapena yakunja.
• Kusamuka kwa pulasitiki:Popanda kulimbitsa matrix mothandizidwa ndi stabilizer, ma plasticizers amatuluka pakapita nthawi, zomwe zimapangitsa kuti kuuma ndi kusweka kukhale kovuta.
Udindo Wochepetsa Mavuto a PVC Stabilizers: Njira ndi Mtengo
Ma PVC stabilizers amathetsa mavutowa poyang'ana njira zowonongeka pamlingo wa maselo, ndi mapangidwe amakono ogawidwa m'magulu ogwira ntchito:
▼ Zolimbitsa Kutentha
Izi zimagwira ntchito ngati zowononga HCl ndi zowononga unyolo:
• Zimaletsa HCl yotulutsidwa (kudzera mu reaction ndi sopo wachitsulo kapena organic ligands) kuti ziletse autocatalysis, zomwe zimapangitsa kuti mawindo azitha kugwira ntchito bwino kwa mphindi 20-40.
• Zolimbitsa thupi za organic (monga ma phenols oletsedwa) zimasunga ma free radicals omwe amapangidwa panthawi yowonongeka, kusunga umphumphu wa unyolo wa mamolekyu ndikuletsa kusintha kwa mtundu.
▼ Zolimbitsa Magetsi
Pogwirizana ndi machitidwe a kutentha, amayamwa kapena kuwononga mphamvu ya UV:
• Zoyamwa UV (monga benzophenones) zimasintha kuwala kwa UV kukhala kutentha kosavulaza, pomwe zoletsa kuwala kwa amine (HALS) zimabwezeretsa magawo a polima owonongeka, zomwe zimapangitsa kuti ntchito yakunja ya chipangizocho ichuluke kawiri.
▼ Mafomula Osawononga Chilengedwe
Zokhazikika za Calcium-zinc (Ca-Zn)asintha mitundu yosiyanasiyana ya heavy metal, kukwaniritsa zofunikira pa malamulo komanso kusunga magwiridwe antchito. Amachepetsanso mpweya wa VOC ndi 15–25% pochepetsa kuwonongeka kwa kutentha panthawi yokonza.
Zokhazikika ngati Yankho Loyambira
Zokhazikika za PVC sizinthu zowonjezera zokha—koma zimathandiza kupanga PVC-AL. Mwa kuchepetsa kuwonongeka kwa kutentha, kuonetsetsa kuti malamulo akutsatira malamulo, komanso kulimbitsa kulimba, zimathetsa zolakwika za polima. Komabe, sizingathetse mavuto onse amakampani: kupita patsogolo kwa mapulasitiki opangidwa ndi zinthu zachilengedwe komanso kubwezeretsanso mankhwala ndikofunikira kuti PVC-AL igwirizane bwino ndi zolinga zachuma. Komabe, pakadali pano, machitidwe okhazikika okonzedwa bwino ndi njira yokhwima kwambiri komanso yotsika mtengo yopezera chikopa chopangidwa ndi PVC chapamwamba komanso chogwirizana ndi malamulo.
Nthawi yotumizira: Novembala-12-2025