[Mitundu ya matumba oluka]

Kupanga kwakunja makamaka ndi polyethylene (PE), kupanga kwapakhomo makamaka ndi polypropylene (PP), ndi mtundu wa utomoni wa thermoplastic wopangidwa ndi ethylene polymerization. Mu mafakitale, imaphatikizaponso ma copolymers a ethylene okhala ndi -olefin yaying'ono. Polyethylene yopanda fungo, yopanda poizoni, imamveka ngati sera, imakhala ndi kukana kutentha kochepa (kutentha kotsika kwambiri komwe kumagwiritsidwa ntchito kumatha kufika -70 ~ -100℃), kukhazikika kwabwino kwa mankhwala, imatha kupirira kukokoloka kwa asidi ndi alkali (palibe okosijeni wa asidi), kutentha kwa chipinda sikusungunuka mu zosungunulira zonse, kuyamwa pang'ono kwa madzi, magwiridwe antchito abwino kwambiri amagetsi; Koma polyethylene imakhudzidwa ndi zovuta zachilengedwe (mankhwala ndi zotsatira za makina) ndipo imakana kukalamba kutentha. Katundu wa polyethylene amasiyana malinga ndi mitundu, makamaka kutengera kapangidwe ka mamolekyulu ndi kuchulukana. Zogulitsa zomwe zimakhala ndi kuchuluka kosiyana (0.91 ~ 0.96g/cm3) zitha kupezeka pogwiritsa ntchito njira zosiyanasiyana zopangira. Polyethylene imatha kukonzedwa pogwiritsa ntchito njira yopangira thermoplastic (onani pulasitiki). Amagwiritsidwa ntchito kwambiri popanga filimu, chidebe, chitoliro, waya umodzi, waya ndi chingwe, zofunikira za tsiku ndi tsiku, ndi zina zotero, ndipo angagwiritsidwe ntchito ngati zipangizo zotetezera ma TV, radar, ndi zina zotero. Ndi chitukuko cha mafakitale a petrochemical, kupanga polyethylene kwakula mofulumira, kutulutsa pafupifupi 1/4 ya kupanga pulasitiki konse. Mu 1983, mphamvu yonse yopangira polyethylene inali 24.65Mt, ndipo mphamvu ya fakitale yomwe ikumangidwa inali 3.16Mt.

Polypropylene (PP)

Utomoni wa thermoplastic wokonzedwa ndi polymerization ya propylene. Pali mitundu itatu ya zinthu zosasinthika, zosalamulirika komanso zosakanikirana, ndipo zinthu zosasinthika ndi zinthu zazikulu zomwe zimapangidwa m'mafakitale. Polypropylene imaphatikizaponso ma copolymer a propylene ndi ethylene yochepa. Nthawi zambiri imakhala yowala yopanda utoto, yopanda fungo, yopanda poizoni. Chifukwa kapangidwe kake ndi koyera komanso kolimba kwambiri, kotero malo osungunuka mpaka 167℃, kukana kutentha, zinthu zingagwiritsidwe ntchito kuyeretsa nthunzi ndi ubwino wake waukulu. Ndi kuchuluka kwa 0.90g/cm3, ndi pulasitiki yopepuka kwambiri padziko lonse lapansi. Kukana dzimbiri, mphamvu yokoka 30MPa, mphamvu, kuuma ndi kuwonekera bwino ndikwabwino kuposa polyethylene. Choyipa chake ndi kukana kutentha kochepa komanso kukalamba mosavuta, komwe kumatha kuthetsedwa mwa kusintha ndi kuwonjezera antioxidant motsatana.

Mtundu wa thumba lolukidwa nthawi zambiri umakhala woyera kapena imvi, suli ndi poizoni komanso wopanda kukoma, nthawi zambiri suvulaza thupi la munthu, ngakhale kuti umapangidwa ndi mapulasitiki osiyanasiyana a mankhwala, koma chitetezo chake cha chilengedwe ndi champhamvu, ndipo mphamvu yobwezeretsanso zinthu ndi yayikulu;

Matumba opangidwa ndi nsalu amagwiritsidwa ntchito kwambiri, makamaka popakira ndi kulongedza zinthu zosiyanasiyana, ndipo amagwiritsidwa ntchito kwambiri m'makampani;

Chikwama chopangidwa ndi pulasitiki chimapangidwa ndi polypropylene resin ngati chinthu chachikulu chopangira zinthu, chomwe chimatulutsidwa ndikutambasulidwa kukhala silika wathyathyathya, kenako n’kusokedwa ndikupanga matumba.

Chikwama chopangidwa ndi pulasitiki chopangidwa ndi zinthu zosiyanasiyana chimachokera ku nsalu yopangidwa ndi pulasitiki, yomwe imapangidwa pogwiritsa ntchito njira yozungulira.

Zinthu zingapozi zimagwiritsidwa ntchito polongedza ufa kapena zinthu zolimba zopangidwa ndi granular komanso zinthu zosinthasintha. Chikwama chopangidwa ndi pulasitiki chopangidwa ndi pulasitiki chimagawidwa m'matumba awiri mkati mwa chimodzi ndi atatu mkati mwa chimodzi malinga ndi kapangidwe kake ka zinthuzo.

Malinga ndi njira yosokera, ikhoza kugawidwa m'magawo awiri: thumba la pansi losokera, thumba la pansi losokera, thumba lolowetsa ndi thumba losokera lomangirira.

Malinga ndi kukula kwa thumba, lingagawidwe m'magulu 350, 450, 500, 550, 600, 650 ndi 700mm. Mafotokozedwe apadera ayenera kuvomerezedwa ndi onse awiri.