Zinthu zopangidwa ndi PVC thovu zimakhala zoyera, koma nthawi zina zimakhala zachikasu zikasungidwa kwa nthawi yayitali. Chifukwa chake ndi chiyani?

Choyamba, muyenera kudziwa ngati pali vuto ndi chotsukira thovu chomwe mwasankha. Chotsukira thovu cha PVC chimagwiritsa ntchito chotsukira thovu kuti chiwole ndikupanga mpweya womwe umayambitsa ma pores. Pamene kutentha kwa chotsukira kumatha kufika kutentha kwa chotsukira thovu, mwachibadwa sichidzatulutsa thovu. Mitundu yosiyanasiyana ya zotsukira thovu imakhala ndi kutentha kosiyana kwa kuwonongeka, ngakhale mtundu womwewo wa chotsukira thovu utapangidwa ndi opanga osiyanasiyana, kutentha kwa kuwonongeka sikungakhale kofanana kwenikweni. Sankhani chotsukira thovu cha PVC chomwe chikuyenererani. Si PVC yonse yoyenera kutsukira thovu, kotero ndikofunikira kusankha zipangizo zomwe zili ndi digiri yotsika ya polymerization. Zipangizo zotere zimakhala ndi kutentha kochepa kwa processing, monga S700. Ngati mukufuna kugwiritsa ntchito 1000 ndi 700, zitha kukhala zosiyana. Chotsukira thovu chikhoza kukhala kuti chavunda kale ndipo PVC sinasungunukebe.

Kuphatikiza apo, pali zowonjezera zina. Kutentha kwa chopangira thovu chachizolowezi kumakhala kokwera kuposa kutentha kwa PVC. Ngati zowonjezera zoyenera siziwonjezeredwa, zotsatira zake ndi zakuti PVC imawola (imasintha kukhala yachikasu kapena yakuda) ndipo ACR sinawolebe (thovu). Chifukwa chake, ndikofunikira kuwonjezera zokhazikika kuti PVC ikhale yokhazikika (siiwola kutentha koyeserera kwa AC). Kumbali ina, zowonjezera zomwe zimalimbikitsa thovu la AC zimawonjezeredwa kuti zichepetse kutentha kwa AC ndikuyigwirizana nayo. Palinso zowonjezera kuti zipangitse ma pores a thovu kukhala ang'onoang'ono komanso okhuthala, zomwe zimapangitsa kuti ma pores akuluakulu a thovu asamapitirire ndikuchepetsa mphamvu ya chinthucho. Popeza kutentha kuli kotsika ndipo sikusandukanso achikasu, ndikutsimikizira kuti kutentha kwanu kwapamwamba kunapangitsa kuti PVC iwole ndikukhala yachikasu. Kuwola kwa PVC ndi njira yodzipangira yokha, zomwe zikutanthauza kuti zinthu zowola zimalimbikitsa kuwola kwina. Chifukwa chake, nthawi zambiri zimawoneka kuti zili bwino ngati kutentha sikuli kokwera, koma ngati kutentha kuli kokwera pang'ono, kudzawola kwambiri.