Te Tūranga o ngā Whakapūmau PVC i roto i te Hanga Werohanga me te Whai Hua o te Tukanga

Ko te whakahāngai werohanga tetahi o ngā tukanga hanga tino whai hua, tino whai hua hoki mō teNgā hua PVC (polyvinyl chloride), e āhei ai te whakaputa i ngā āhua uaua me te tino tika - mai i ngā wāhanga motuka me ngā whare hiko ki ngā taputapu hauora me ngā taonga o te whare. Heoi, he wero motuhake te hanganga ngota o te PVC i te wā tukatuka: he kore pumau ina pāngia e ngā pāmahana teitei (te nuinga o te 160–220°C) me ngā kaha kutikuti e pā ana ki te hanga werohanga. Ki te kore he pumau tika, ka pakaru te PVC, ka puta te tae koretake (te kōwhai, te parauri rānei), ka heke ngā āhuatanga miihini, tae noa ki te tukunga o ngā hua taha kino. Koinei te wāhi e uru mai ai ngā kaiwhakaū PVC hei toa kāore i te mohiotia, ehara i te mea ko te aukati i te pirau engari ko te whakapai ake i te mahi tukatuka me te whakarite kia tutuki te hua whakamutunga i ngā paerewa kounga. I roto i tēnei tuhinga, ka rukuhia e mātou te tūranga nui o ngā kaiwhakaū PVC i roto i te hanga werohanga, ka tūhura i ngā momo tino noa, ka tirohia me pēhea te awe i ngā tawhā tukatuka matua me te mahi hua mutunga.

Hei mārama he aha ngā mea whakaū e kore e taea te whiriwhiri mō te hanga i te PVC, me mārama tuatahi ki te pūtake o te kore pumau o te PVC. Ko te PVC he pūmua winiru i hangaia e te whakapūmuatanga o ngā monomer vinyl chloride, ā, kei roto i tōna mekameka ngota he hononga chlorine-waro ngoikore. Ina werahia ki ngā pāmahana e hiahiatia ana mō te hanga i te weronga, ka pakaru ēnei hononga, ka tīmata he tauhohenga mekameka o te pirau. Ko tēnei tukanga, e mōhiotia ana ko te dehydrochlorination, ka tukuna he hau hauwai chloride (HCl) - he matū waikura e tere ake ai te pirau me te kino i ngā taputapu hanga. Hei tāpiri, ko te dehydrochlorination ka arahi ki te hanganga o ngā hononga takirua honohono i roto i te mekameka PVC, ka huri te rauemi ki te kōwhai, kātahi ka parauri, ā, i te mutunga ka pakarukaru. Mō ngā kaihanga inenga, ko te tikanga o tēnei he wāhanga kua parahia, he pikinga o ngā utu tiaki, me te kore e tutuki i ngā ture haumaru me te kounga. Ka whakakorea e ngā whakaū tēnei huringa pirau mā te mimiti i te HCl, te whakakore i ngā hua waikawa, te tango rānei i ngā rauropi kore utu e akiaki ana i te tauhohenga mekameka - e tiaki pai ana i te PVC i te wā tukatuka me te whakaroa i te roa o te mahi a te rauemi.

Ehara i te katoaNgā whakaū PVChe ōrite te hanganga, ā, ko te whiriwhiri i te momo tika mō te whakakoi werohanga e whakawhirinaki ana ki ngā āhuatanga maha: te pāmahana tukatuka, te wā huringa, te uaua o te pokepokea ai, ngā whakaritenga hua mutunga (hei tauira, te pa ki te kai, te ātete ki te UV), me ngā ture taiao. Kei raro nei he tirohanga whānui o ngā momo whakaū e whakamahia whānuitia ana i roto i te whakakoi werohanga, ā rātou tikanga mahi, me ngā painga me ngā huakore matua mō ngā tono tukatuka:

I roto i te ao ture o ēnei rā, ko te ārahi me teNgā kaiwhakaū Ba-Cdkua whakakorea te nuinga o te wā, ā, kua whakamahia ngā momo kē atu o te organotin me te Ca-Zn, inā koa mō ngā hua e aro ana ki te kaihoko me ngā hua hauora. Mō ngā kaihanga pokepoke werohanga, ko te tikanga o tēnei panonitanga he urutau ki ngā āhuatanga tukatuka ahurei o ēnei whakaū haumaru ake—hei tauira, te whakarerekē i ngā pāmahana, i ngā wā huringa rānei hei whakauru i te pumau wera iti o te Ca-Zn, te whakataurite rānei i te utu me te mahi ina whakamahia ana ngā organotin.

Ko te pānga o ngā mea whakaū ki te mahi tukatuka PVC i roto i te whakahāngai werohanga he nui atu i te aukati noa i te pirau. Ka pā tika ki ngā tawhā tukatuka matua pēnei i te taupū rere rewa, te wā huringa, te whakakī pokepokea ai, me te whakapaunga pūngao—e pā ana ēnei ki te pai o te whakaputa me te kounga o ngā wāhanga. Me wehewehe ēnei pānga ki te horopaki o te ao tūturu: hei tauira, he mea nui te rere rewa kia pai ai te whakakī a te matū PVC i ngā kōhao pokepokea ai uaua, me te kore he hapa pēnei i te pupuhi poto, i ngā raina whakarewa rānei. Nā te iti o te horopeta me te hototahitanga pai ki te PVC, he iti noa te pānga o ngā mea whakaū organotin ki te MFI, e āhei ai te rere o te rewa kia maeneene ahakoa i roto i ngā wāhanga angiangi, i ngā āhuahanga uaua rānei.Ngā mea whakaū Ca-Zn, i tētahi atu ringa, ka paku piki ake pea te matotoru o te rewa (ina koa i ngā horopeta teitei ake), me whakarite e ngā kaihanga pokepoke te pēhanga werohanga, te pāmahana rānei kia mau tonu ai te rere pai. He mea nui tēnei hei whakaaroaro ina huri mai i ngā organotin ki te Ca-Zn kia tutuki ai ngā ture—ka taea e ngā whakarerekētanga iti ki ngā tawhā tukatuka te hanga rerekētanga nui ki te kounga o te wāhanga.

Ko te wā huringa tētahi atu mea nui mō ngā kaihanga pokepoke werohanga, nā te mea ka pā tika ki te nui o te whakaputanga. Mā ngā mea whakau me te pumau wera kaha, pērā i ngā organotin, i te mata rānei (ahakoa kua whakawhāitihia inaianei), ka taea te whakapoto i ngā wā huringa mā te whakahohe i ngā pāmahana tukatuka teitei ake me te kore e pirau. Ka whakaitihia e ngā pāmahana teitei ake te matotoru rewa, ka tere ake te whakakī i te pokepoke, ka whakapoto i ngā wā whakamatao—ka whakanuia katoatia e ēnei te hua. I tetahi atu taha, ko ngā mea whakau me te pumau wera iti ake, pērā i te Ca-Zn, me roa ake pea ngā wā huringa kia kore ai e wera rawa, engari he maha ngā wā ka whakamanahia tēnei taurite e ō rātou painga taiao me te tutuki i ngā ture. Ka taea e ngā kaihanga pokepoke te whakaiti i tēnei mā te arotau i ētahi atu tawhā, pērā i te whakamahi i ngā kaiwhakahaere pāmahana pokepoke, te whakarerekē rānei i te tere o te tīwiri hei whakaiti i te wera i puta mai i te kutikuti.

He mea nui anō hoki te pumau o te kutikuti, inā koa mō ngā tukanga whakakoi werohanga e whakamahi ana i ngā tere tīwiri teitei. Ka puta he wera tāpiri i roto i te rewa PVC nā ngā kaha kutikuti, ka piki ake te mōrearea o te pirau. Ko ngā whakau ka taea te tu atu ki te kutikuti teitei—pērā i ngā organotin me ngā ranunga Ca-Zn mahi teitei—ka āwhina ki te pupuri i te pumau o te rewa i raro i ēnei āhuatanga, ka ārai i te tae kerekere me te whakarite i ngā āhuatanga wāhanga ōrite. He rerekē, ka pakaru pea ngā whakau kounga iti i raro i te kutikuti teitei, ka hua ake he rere rewa kore taurite me ngā hapa pēnei i ngā koha mata, ngā ahotea ā-roto rānei.

Ko te mahi a te hua whakamutunga e whakawhirinaki ana ki te whiriwhiri i te mea whakaū. Hei tauira, ko ngā hua PVC o waho (hei tauira, ngā taonga māra, te whakakikorua o waho) me whakamahi i ngā whakaū me te ātete ki te UV hei ārai i te pirau mai i te rā. He maha ngā whakaū Ca-Zn me te organotin ka taea te hanga me ngā mimiti UV, ngā whakaū mārama amine ārai rānei (HALS) hei whakarei ake i te ātete ki te huarere. Mō ngā hua PVC pakari pērā i ngā hononga paipa, i ngā whare hiko rānei, he mea nui ngā whakaū e whakapai ake ana i te kaha pānga me te pumau o ngā āhuatanga. Ko ngā organotin, ina koa, e mōhiotia ana mō te tiaki i ngā āhuatanga miihini o te PVC pakari i te wā tukatuka, kia taea ai e ngā wāhanga te tu atu ki te ahotea me te pupuri i tō rātou āhua i roto i te wā.

Ko ngā whakamahinga e pā ana ki te kai me te rongoā e hiahia ana ki ngā whakaū kāore e paitini, ā, e tutuki ana i ngā paerewa o te ao. Ko ngā whakaū Ca-Zn te paerewa koura i konei, nā te mea kāore he konganuku taumaha, ā, e tutuki ana i ngā whakaritenga haumaru tino kaha. Ka whakamahia hoki ngā organotin i roto i ētahi whakamahinga e pā ana ki te kai, engari ko ngā momo motuhake anake (hei tauira, te methyltin, te butyltin) kua whakaaetia mō taua whakamahinga. Me āta manatoko e ngā kaihanga pokepoke e mahi ana i roto i ēnei rāngai te tutuki o ā rātou hanganga whakaū kia kore ai e puta he take ture, kia mau ai hoki te haumaru o te kaihoko.

I te wā e whiriwhiri ana i tētahiWhakapūmau PVC mō te whakakoi werohanga, he maha ngā whakaaro mahi hei maumahara atu i tua atu i te momo me te mahi anake. He mea nui te hototahi ki ētahi atu tāpiringa—he maha ngā wā kei roto i ngā matū PVC ngā mea hanga kirihou, ngā hinu whakahinuhinu, ngā whakakī, me ngā tae, ā, me mahi tahi te kaiwhakaū me ēnei wāhanga. Hei tauira, ka taea e ētahi hinu whakahinuhinu te whakaiti i te whai huatanga o ngā kaiwhakaū mā te hanga i tētahi arai i waenga i te kaiwhakaū me te anga PVC, nō reira me whakarerekē pea e ngā kaihanga te taumata hinu whakahinuhinu, te whiriwhiri rānei i tētahi kaiwhakaū he pai ake te hototahi. Ko te inenga tētahi atu mea nui: mā te whakamahi i te iti rawa o te kaiwhakaū ka hua ake he koretake te tiaki me te pirau, ko te whakamahi nui ka arahi ki te pua (te wāhi e heke ai te kaiwhakaū ki te mata o te wāhanga) te heke rānei o ngā āhuatanga miihini. Ko te nuinga o ngā kaihanga kaiwhakaū e whakarato ana i ngā awhe inenga kua tūtohutia i runga i te momo PVC (pakari vs. ngāwari) me ngā tikanga tukatuka, ā, he mea nui kia whai i ēnei aratohu i te wā e whakahaere ana i ngā oma whakamātautau hei arotau i te mahi.

Kei te hangaia hoki e ngā ia o te taiao me ngā ture te heke mai o ngā whakaū PVC mō te whakakoi werohanga. Nā te akiaki o te ao mō te oranga tonutanga kua piki ake te hiahia mō ngā whakaū e ahu mai ana i te koiora, e pirau rānei, ahakoa kei ngā wāhanga tōmua tonu o te whanaketanga. Hei tāpiri, ko ngā ture e aukati ana i te whakamahinga o ētahi matū (hei tauira, REACH i te EU) kei te akiaki i te auahatanga ki ngā hanganga haumaru ake, e pai ake ana ki te taiao. Me noho mōhio tonu ngā kaihanga mō ēnei ia kia mau tonu ai ā rātou tukanga ki te tutuki i ngā whakaritenga me te whakataetae. Hei tauira, mā te huri ki ngā whakaū Ca-Zn ināianei ka āwhina i te karo i ngā raruraru mēnā ka whakatinanahia ngā ture pakari ake mō ngā organotin a muri ake nei.

Hei whakaatu i te pānga o te whiriwhiri i te pūmau i te ao tūturu, me whakaaro tātou ki tētahi rangahau take: he kaihanga pokepoke e hanga ana i ngā ārai hiko PVC pakari mā te pokepoke werohanga i pāngia e te kōwhai tonu o ngā wāhanga me te tere para nui. I whakaatuhia e ngā rangahau tuatahi kei te whakamahi te kaihanga pokepoke i tētahi pūmau Ba-Cd utu iti, ehara i te mea kāore i te tutuki i ngā ture a te EU engari kāore hoki i te tino tiaki i te PVC i te pāmahana tukatuka teitei (200°C) e hiahiatia ana mō te hoahoa pokepoke uaua. Whai muri i te huri ki tētahi pūmau organotin mahi-teitei, i whakakorea te take kōwhai, i heke ngā tere para mā te 35%, ā, i tutuki ngā wāhanga i ngā paerewa haumaru a te EU. I kite anō te kaihanga pokepoke i te pai ake o te rere rewa, i whakaiti i te pēhanga werohanga me te whakapoto i ngā wā huringa mā te 10%, i whakanui ake i te hua whānui. I tētahi atu tauira, i huri tētahi kaihanga o ngā ipu PVC kai-kai mai i ngā organotin ki tētahi pūmau Ca-Zn hei whakatutuki i ngā whakaritenga a te FDA. Ahakoa i tika kia paku whakarerekētia te pāmahana tukatuka (mā te whakaheke i te 195°C ki te 185°C) kia mau tonu ai te pumau, he maeneene te pana, he iti noa te pānga ki te wā huringa, ā, i mau tonu te mārama me ngā āhuatanga hangarau o ngā wāhanga.

He mea nui ngā whakaū PVC mō te angitū o te hanga whakarewa, hei ārai i te pirau, hei āwhina hoki i te mahi tukatuka tino pai. Ko te whiriwhiri i te whakaū—ahakoa he organotin, he Ca-Zn, he momo rānei—me whakarite ki ngā tikanga tukatuka motuhake, ki ngā whakaritenga hua mutunga, me ngā here ture. Ko ngā kaihanga whakarewa e whakapau ana i te wā ki te whiriwhiri i te whakaū tika me te arotau i ngā tawhā tukatuka i runga i taua kōwhiringa ka whai hua mai i ngā reiti para iti ake, te hua teitei ake, me ngā wāhanga kounga teitei e tutuki ana i ngā paerewa haumaru me te mahi. I te haere tonu o te ahumahi ki te whanake ki te pumau me ngā ture pakari ake, ko te noho mōhio ki ngā hangarau whakaū hou me ngā ia o te mea nui hei pupuri i te painga whakataetae. Ahakoa kei te whakaputa koe i ngā wāhanga PVC pakari, ngāwari rānei, mō te whakamahinga kaihoko, ahumahi rānei, ko te whakaū tika te tūāpapa o te tukanga hanga whakarewa angitu.