(PVC) he thermoplastic kaulana ʻole, paʻa, palupalu, a keʻokeʻo maʻamau.Aia i kēia manawa ke kolu o ka plastic i hoʻohana nui ʻia ma ka honua (ma hope o ka polyethylene a me ka polypropylene).Hoʻohana pinepine ʻia ʻo PVC i ka paipu a me nā noi wai, ʻoiai ke kūʻai ʻia nei ma ke ʻano o nā pellets a i ʻole he resin i kona ʻano pauka.
Hoʻohana i ka PVC
ʻO ka hoʻohana ʻana o PVC ka mea nui i ka ʻoihana kūkulu hale.Hoʻohana mau ʻia ʻo ia ma ke ʻano he pani a i ʻole nā mea ʻē aʻe no nā paipu metala (ʻoi aku ke keleawe, ke kila galvanized, a i ʻole ka hao hao), a ma nā noi he nui kahi e hiki ai i ka corrosion ke hoʻololi i ka hana a hoʻonui i nā kumukūʻai mālama.Ma waho aʻe o nā noi noho, hoʻohana mau ʻia ʻo PVC no nā ʻoihana kaona, ʻoihana, pūʻali koa, a me nā ʻoihana kalepa.
Ma keʻano laulā, ʻoi aku ka maʻalahi o ka PVC ma mua o ka paipu metala.Hiki keʻokiʻia i ka lōʻihi i makemakeʻia me nā mea hana lima maʻalahi.ʻAʻole pono e wili ʻia nā paipu a me nā paipu.Hoʻopiliʻia nā paipu me ka hoʻohanaʻana i nā hono, ka mea hoʻoheheʻe cement, a me nā glues kūikawā.ʻO kekahi mea maikaʻi o PVC ʻo ia kekahi mau huahana i hoʻohui ʻia i nā plasticizers ʻoi aku ka palupalu a ʻoi aku ka maʻalahi, e kūʻē i ka paʻa, e maʻalahi ai ka hoʻouka ʻana.Hoʻohana nui ʻia ʻo PVC i nā ʻano maʻalahi a paʻa hoʻi e like me ka insulation no nā mea uila e like me ke uea a me ke kaula.
Ma ka ʻoihana mālama ola, hiki ke loaʻa ka PVC ma ke ʻano o nā paipu hānai, nā ʻeke koko, nā ʻeke intravenous (IV), nā ʻāpana o nā mea dialysis, a me nā mea ʻē aʻe.Pono e hoʻomaopopo ʻia he hiki ke hoʻohana wale ʻia i ka wā e hoʻohui ʻia ai nā phthalates - nā kemika e hana ana i nā māka maʻalahi o PVC a me nā plastics ʻē aʻe - i ka hana PVC.
ʻO nā huahana mea kūʻai maʻamau e like me ka ua, ʻeke ʻeke, nā mea pāʻani a nā keiki, nā kāleka hōʻaiʻē, nā kīhāpai kīhāpai, nā pani puka a me nā puka makani, a me nā pale ʻauʻau-e inoa i kekahi mau mea āu e ʻike ai i loko o kou ʻohana ponoʻī-ua hana pū ʻia me PVC i loko. kekahi ʻano a i ʻole kekahi.
Pehea i hana ʻia ai ka PVC
ʻOiai ʻo ka plastics he mea i hana ʻia e ke kanaka, ʻo nā mea nui ʻelua i komo i loko o ka PVC-paʻakai a me ka ʻaila-he mea kūlohelohe.No ka hana ʻana i ka PVC, ʻo ka mea mua āu e hana ai, ʻo ia ka hoʻokaʻawale ʻana i ka ethylene, kahi kumu kinoea maoli, mai ka mea i kapa ʻia ʻo "ka mea hānai."Ma ka ʻoihana kemika, ʻo ka ʻaila ka meaʻai i koho ʻia no nā kinikini he nui, me ka methane, propylene, a me ka butane.(ʻO nā meaʻai kūlohelohe nā algae, kahi meaʻai maʻamau no nā wahie hydrocarbon, me ka kulina a me ke kō, ʻo ia nā meaʻai ʻē aʻe no ka ethanol.)
No ka hoʻokaʻawale ʻana i ka ethanol, hoʻomehana ʻia ka ʻaila wai i loko o ka umu mahu a hoʻokomo ʻia ma lalo o ke kaomi loa (kahi kaʻina i kapa ʻia ʻo thermal cracking) e hoʻololi i ke kaumaha molekala o nā kinikona i loko o ka meaʻai.Ma ka hoʻololi ʻana i kona kaumaha molekala, hiki ke ʻike, hoʻokaʻawale ʻia a ʻohi ʻia ka ethylene.Pau kēlā, hoʻomāʻalili ʻia i kona ʻano wai.
ʻO ka ʻaoʻao aʻe o ke kaʻina hana ʻo ia ka unuhi ʻana i ka ʻāpana chlorine mai ka paʻakai i loko o ka wai kai.Ma ka hoʻokuʻu ʻana i kahi au uila ikaika ma o ka wai paʻakai (electrolysis), hoʻohui ʻia kahi electron hou i nā molekala chlorine, e ʻae iā lākou e ʻike, hoʻokaʻawale ʻia, a unuhi ʻia.
I kēia manawa iā ʻoe nā mea nui.
I ka hui ʻana o ka ethylene a me ka chlorine, ʻo ka hopena kemika a lākou e hana ai e hana i ka ethylene dichloride (EDC).Ke hana nei ka EDC i ke kaʻina hana hoʻoheheʻe wela ʻelua, ʻo ia hoʻi, hoʻopuka i ka vinyl chloride monomer (VCM).A laila, hoʻoili ʻia ka VCM i loko o kahi reactor i loko o ka catalyst, kahi e hoʻopili ai nā molekala VCM (polymerization).Ke loulou nā molekala VCM, loaʻa iā ʻoe ka resin PVC—ke kumu no nā pūhui vinyl āpau.
Hoʻokumu ʻia nā pūhui vinyl paʻa, ʻoluʻolu, a hui pū ʻia paha e ka hui ʻana i ka resin me nā ʻano hana like ʻole o nā plasticizers, stabilizers, a me nā mea hoʻololi e hoʻokō ai i nā waiwai i makemake ʻia e komo i nā mea āpau mai ka waihoʻoluʻu, ka ʻano, a me ka maʻalahi i ka lōʻihi i ka wā wela a me nā kūlana UV.
Nā pōmaikaʻi o PVC
ʻO PVC kahi mea kūʻai haʻahaʻa he māmā, malleable, a maʻalahi hoʻi e mālama a hoʻokomo.Ke hoʻohālikelike ʻia me nā ʻano polymers ʻē aʻe, ʻaʻole i kaupalena ʻia kāna kaʻina hana i ka hoʻohana ʻana i ka aila ʻaila a i ʻole ke kinoea maoli.(Ke hoʻopaʻapaʻa nei kekahi e hoʻolilo kēia i ka PVC i "plastic plastic sustainable" no ka mea ʻaʻole ia e hilinaʻi i nā ʻano ikehu ʻole.)
He lōʻihi nō hoʻi ka PVC a ʻaʻole pili ʻia e ka corrosion a i ʻole nā ʻano hoʻohaʻahaʻa ʻē aʻe, a no laila, hiki ke mālama ʻia no nā manawa lōʻihi.Hiki ke hoʻololi maʻalahi i kāna hoʻolālā i nā ʻano like ʻole no ka hoʻohana ʻana ma waena o nā ʻoihana like ʻole a me nā noi, ʻo ia ka mea hoʻohui.Loaʻa i ka PVC ke kūpaʻa kemika, he mea nui ia i ka wā e hoʻohana ʻia ai nā huahana PVC i nā kaiapuni me nā ʻano kemika like ʻole.Hōʻoia kēia ʻano i ka mālama ʻana o PVC i kāna mau waiwai me ka ʻole o ka hoʻololi nui ʻana i ka wā e hoʻokomo ʻia ai nā kemika.ʻO nā pono ʻē aʻe he:
● Biocompatibility
● Mākaʻikaʻi a me ka ʻike
● Kū'ē i ka pohā koʻikoʻi kemika
● Haʻahaʻa thermal conductivity
● Pono liʻiliʻi a mālama ʻole
Ma ke ʻano he thermoplastic, hiki ke hana hou ʻia ka PVC a hoʻololi i nā huahana hou no nā ʻoihana like ʻole, ʻoiai ma muli o nā ʻano hana like ʻole i hoʻohana ʻia no ka hana ʻana i ka PVC, ʻaʻole ia he hana maʻalahi.
Nā hemahema o PVC
Hiki i ka PVC ke komo i ka 57% chlorine.Hoʻohana pinepine ʻia ke kalapona—i loaʻa mai i nā huahana ʻaila—i kāna hana ʻana.Ma muli o nā toxins i hiki ke hoʻokuʻu ʻia i ka wā o ka hana ʻana, i ka wā e ʻike ʻia ai i ke ahi, a i ʻole i ka pohō ʻana i loko o nā ʻāina, ua kapa ʻia ʻo PVC e kekahi mau mea noiʻi olakino a me nā mea hoʻokele kaiapuni ʻo ia ka "poison plastic."
ʻAʻole i hōʻoia ʻia nā pilikia olakino e pili ana i ka PVC, akā naʻe, ua hoʻopili ʻia kēia mau mea ʻawaʻawa i nā kūlana e pili ana akā ʻaʻole i kaupalena ʻia i ka maʻi kanesa, ka hoʻomohala ʻana o ka fetal, ka hoʻopau ʻana i ka endocrine, ka hānō, a me ka emi ʻana o ka hana māmā.ʻOiai ke kuhikuhi nei nā mea hana i ka paʻakai kiʻekiʻe o PVC ma ke ʻano he kūlohelohe a ʻano ʻino ʻole, ʻōlelo ʻia ka ʻepekema ʻo ka sodium-me ka hoʻokuʻu ʻana o ka dioxin a me ka phthalate-ʻo ia ka mea e hiki ke kōkua i nā pōʻino o ke kaiapuni a me ke olakino a PVC.
ʻO ka wā e hiki mai ana o PVC Plastics
ʻO nā hopohopo e pili ana i nā pilikia pili i ka PVC a ua hoʻoikaika i ka noiʻi ʻana i ka hoʻohana ʻana i ka ethanol kō no ka meaʻai ma mua o ka naphtha (he ʻaila puhi i loaʻa ma ka hoʻomaloʻo maloʻo o ka lanahu, shale, a i ʻole ka aila).Ke hana ʻia nei nā haʻawina hou ma nā plasticizers bio-based me ka pahuhopu o ka hana ʻana i nā koho phthalate-free.ʻOiai aia kēia mau hoʻokolohua i ko lākou pae mua, ʻo ka manaʻolana e hoʻomohala i nā ʻano PVC i hoʻomau ʻia e hōʻemi i ka hopena maikaʻi ʻole i ke olakino kanaka a me ke kaiapuni i ka wā o ka hana ʻana, hoʻohana a me ka hoʻokuʻu ʻana.
Ka manawa hoʻouna: Apr-07-2022