Polyethylene (PE)
1. Hana o ka PE
ʻO PE ka palakika i hana nui ʻia ma waena o nā palakika, me ka nui o kahi 0.94g/cm3. Hōʻike ʻia ia ma ke ʻano translucent, palupalu, ʻaʻohe ʻawaʻawa, makepono, a maʻalahi hoʻi e hana. He polymer crystalline maʻamau ʻo PE a he hanana post-shrinkage. Nui nā ʻano o ia mea, ʻo nā mea i hoʻohana pinepine ʻia ʻo LDPE ka mea palupalu (i ʻike nui ʻia ʻo ka rubber palupalu a i ʻole ka mea pua), HDPE ka mea i ʻike nui ʻia ʻo ka rubber palupalu paʻakikī, ʻoi aku ka paʻakikī ma mua o LDPE, he haʻahaʻa ka transmittance māmā a me ke kiʻekiʻe o ka crystallinity; He hana maikaʻi loa ʻo LLDPE, e like me nā plastics ʻenekinia. He kūpaʻa kemika maikaʻi ko PE, ʻaʻole maʻalahi ke popopo, a he paʻakikī ke paʻi. Pono e oxidized ka ʻili ma mua o ka paʻi ʻana.
2. Ka hoʻopili ʻana o PER
HDPE: nā ʻeke palaki e hoʻopili ana, nā mea pono o kēlā me kēia lā, nā bākeke, nā uea, nā mea pāʻani, nā mea kūkulu hale, nā ipu
LDPE: nā ʻeke palaki e hoʻopili ana, nā pua palaki, nā mea pāʻani, nā uea alapine kiʻekiʻe, nā pepa hana, a pēlā aku.
3. Nā ʻano hana PE
ʻO ka hiʻohiʻona kaulana loa o nā ʻāpana PE, ʻo ia ka nui o ka emi ʻana o ka hoʻoheheʻe ʻana a he maʻalahi hoʻi i ka emi ʻana a me ka hoʻololi ʻana. He haʻahaʻa ka omo ʻana o ka wai o nā mea PE a ʻaʻole pono e hoʻomaloʻo ʻia. He ākea ka laulā o ka mahana hana o ka PE a ʻaʻole maʻalahi ka palaho (ʻo ka mahana palaho ma kahi o 300°C). ʻO ka mahana hana he 180 a 220°C. Inā kiʻekiʻe ke kaomi injection, e kiʻekiʻe ka nui o ka huahana a e liʻiliʻi ka wikiwiki o ka emi ʻana. He wai waena ko PE, no laila pono e lōʻihi ka manawa paʻa a pono e mālama mau ʻia ka mahana o ka hoʻoheheʻe (40-70°C).
Pili ke kekelē o ka crystallization o PE i nā kūlana o ke kaʻina hana hoʻoheheʻe. Loaʻa iā ia kahi mahana paʻa kiʻekiʻe. ʻO ka haʻahaʻa o ka mahana o ka mold, ʻo ka haʻahaʻa o ka crystallinity. . I ka wā o ke kaʻina hana crystallization, ma muli o ka anisotropy o ka shrinkage, hana ʻia ka nui o ke kaumaha kūloko, a maʻalahi nā ʻāpana PE e hoʻololi a haki. ʻO ka hoʻokomo ʻana i ka huahana i loko o ka ʻauʻau wai i loko o ka wai wela 80℃ hiki ke hoʻomaha i ke kaumaha kūloko i kekahi ʻano. I ka wā o ke kaʻina hana hoʻoheheʻe, pono e ʻoi aku ka mahana o ka mea ma mua o ka mahana o ka mold. Pono ke kaomi injection e like me ka hiki me ka hōʻoia ʻana i ka maikaʻi o ka ʻāpana. Pono nui ka hoʻomaʻalili ʻana o ka mold e wikiwiki a kaulike, a pono e wela iki ka huahana i ka wā e wehe ʻia ai.
Polypropylene (PP)
1. Hana o PP
He polymer crystalline ʻo PP me ka density o 0.91g/cm3 wale nō (ʻoi aku ka liʻiliʻi ma mua o ka wai). ʻO PP ka māmā loa i waena o nā plastics i hoʻohana pinepine ʻia. Ma waena o nā plastics maʻamau, ʻo PP ka mea e kū'ē i ka wela maikaʻi loa, me ka mahana deformation wela o 80 a 100°C a hiki ke hoʻolapalapa ʻia i ka wai e paila ana. Loaʻa iā PP ke kū'ē maikaʻi i ka haki ʻana o ke koʻikoʻi a me ke ola luhi kūlou kiʻekiʻe, a ua ʻike nui ʻia ʻo "100% plastic".
ʻOi aku ka maikaʻi o ka hana piha o PP ma mua o nā mea PE. He māmā nā huahana PP, paʻakikī a kūpaʻa i nā kemika. ʻO nā hemahema o PP: pololei haʻahaʻa, paʻakikī lawa ʻole, kūpaʻa maikaʻi ʻole i ka wā, maʻalahi ka hana ʻana i ka "pōʻino keleawe", loaʻa iā ia ka hanana post-shrinkage, a ua maʻalahi nā huahana i ka ʻelemakule, lilo i mea palupalu a hoʻololi ʻia.
2. Hoʻopili ʻana o PP
Nā mea hale like ʻole, nā poʻi ipu aniani, nā paipu lawe kemika, nā ipu kemika, nā lako lapaʻau, nā pepa, nā mea pāʻani, nā filaments, nā kīʻaha wai, nā pahu hoʻololi, nā paipu, nā hinges, a pēlā aku.
3. Nā ʻano hana o PP:
He maikaʻi ka wai o PP i ka mahana hoʻoheheʻe a me ka hana hoʻoheheʻe maikaʻi. ʻElua mau ʻano o PP:
ʻO ka mua: emi nui ka mānoanoa o ka PP heheʻe me ka piʻi ʻana o ka wikiwiki shear (ʻaʻole i hoʻopilikia ʻia e ka mahana);
ʻO ka lua: Kiʻekiʻe ke kekelē o ke kuhikuhi molekala a nui ka helu emi ʻana.
ʻOi aku ka maikaʻi o ka mahana hana o PP ma kahi o 200 ~ 250 ℃. Loaʻa iā ia ke kūpaʻa wela maikaʻi (ʻo ka mahana decomposition he 310 ℃), akā i ke kiʻekiʻe o ka mahana (280 ~ 300 ℃), hiki ke hōʻino inā noho lōʻihi i loko o ka barela. No ka mea, emi nui ka viscosity o PP me ka piʻi ʻana o ka shear rate, ʻo ka hoʻonui ʻana i ke kaomi injection a me ka wikiwiki o ka injection e hoʻomaikaʻi i kona fluidity; no ka hoʻomaikaʻi ʻana i ka shrinkage deformation a me nā dents, pono e hoʻomalu ʻia ka mahana o ka mold i loko o ka laulā o 35 a 65 °C. ʻO ka mahana crystallization he 120 ~ 125 ℃. Hiki i ka PP heheʻe ke hele ma waena o kahi āpau mold haiki loa a hana i kahi lihi ʻoi. I ka wā o ke kaʻina hana heheʻe, pono ʻo PP e omo i ka nui o ka wela heheʻe (wela kikoʻī nui aʻe), a e wela iki ka huahana ma hope o ka puka ʻana mai ka mold. ʻAʻole pono e hoʻomaloʻo ʻia nā mea PP i ka wā o ka hana ʻana, a ʻoi aku ka haʻahaʻa o ka shrinkage a me ka crystallinity o PP ma mua o PE.
Ka manawa hoʻouna: Dec-28-2023
