Hoʻohālikelike ʻana o LLDPE a me LDPE.

ʻO ka polyethylene haʻahaʻa linear, ʻokoʻa ke ʻano mai ka polyethylene haʻahaʻa maʻamau, no ka mea, ʻaʻohe lālā kaulahao lōʻihi. Aia ka linearity o LLDPE i nā kaʻina hana like ʻole a me ka hana ʻana o LLDPE a me LDPE. Hoʻokumu pinepine ʻia ʻo LLDPE e ka copolymerization o ethylene a me nā alpha olefins kiʻekiʻe e like me butene, hexene a i ʻole octene ma ka mahana a me ke kaomi haʻahaʻa. ʻOi aku ka haiki o ka hoʻolaha kaumaha molekala o ka polymer LLDPE i hana ʻia e ke kaʻina hana copolymerization ma mua o ka LDPE maʻamau, a i ka manawa like he ʻano linear e hana ai i nā waiwai rheological like ʻole.

nā waiwai kahe heheʻe

Hoʻololi ʻia nā ʻano kahe heheʻe o ka LLDPE i nā koi o ke kaʻina hana hou, ʻoiai ke kaʻina hana extrusion kiʻiʻoniʻoni, hiki ke hana i nā huahana LLDPE kiʻekiʻe. Hoʻohana ʻia ʻo LLDPE ma nā mākeke kuʻuna āpau no ka polyethylene. ʻO ka hoʻonui ʻia ʻana o ka hoʻolōʻihi, ke komo ʻana, ka hopena a me nā waiwai kū'ē i ka haehae e kūpono ai ʻo LLDPE no nā kiʻiʻoniʻoni. ʻO kona kūpaʻa maikaʻi loa i ka haki ʻana o ke kaiapuni, ke kūpaʻa haʻahaʻa o ka hopena a me ke kūpaʻa warpage e hoʻolilo iā LLDPE i mea hoihoi no ka paipu, ka extrusion pepa a me nā noi hoʻoheheʻe āpau. ʻO ka hoʻohana hou loa o LLDPE he mulch no nā landfills a me nā linings no nā loko ʻōpala.

Hana a me nā ʻano

Hoʻomaka ka hana ʻana o LLDPE me nā mea hoʻouluulu metala hoʻololi, ʻoi aku hoʻi o ke ʻano Ziegler a i ʻole Phillips. ʻO nā kaʻina hana hou e pili ana i nā mea hoʻouluulu metala cycloolefin kekahi koho no ka hana ʻana o LLDPE. Hiki ke hoʻokō ʻia ka hopena polymerization maoli i loko o nā reactors solution a me ke kinoea. ʻO ka maʻamau, ua copolymerized ʻia ʻo octene me ka ethylene a me ka butene i loko o kahi reactor solution phase. Ua polymerized ʻia ʻo Hexene a me ethylene i loko o kahi reactor gas phase. ʻO ka resin LLDPE i hana ʻia i loko o ka reactor gas phase aia ma ke ʻano particulate a hiki ke kūʻai ʻia aku ma ke ʻano he pauka a i ʻole e hana hou ʻia i loko o nā pellets. Ua hoʻomohala ʻia kahi hanauna hou o ka super LLDPE e pili ana i ka hexene a me ka octene e Mobile, Union Carbide. Ua hoʻomaka ʻia nā ʻoihana e like me Novacor lāua ʻo Dow Plastics. Loaʻa i kēia mau mea kahi palena paʻakikī nui a loaʻa iā lākou ka hiki hou no nā noi wehe ʻeke aunoa. Ua ʻike ʻia hoʻi ka resin PE density haʻahaʻa loa (density ma lalo o 0.910g/cc.) i nā makahiki i hala iho nei. Loaʻa iā VLDPES ka maʻalahi a me ka palupalu ʻaʻole hiki iā LLDPE ke hoʻokō. Hōʻike nui ʻia nā waiwai o nā resins i ka helu kuhikuhi heheʻe a me ka nui. Hōʻike ka helu kuhikuhi heheʻe i ke kaumaha molekala awelika o ka resin a ua kāohi nui ʻia e ka mahana hopena. Kūʻokoʻa ke kaumaha molekala awelika mai ka hoʻolaha kaumaha molekala (MWD). Hoʻopilikia ke koho Catalyst i ka MWD. ​​Hoʻoholo ʻia ka nui e ka nui o ka comonomer i loko o ke kaulahao polyethylene. Hoʻomalu ka nui o ka comonomer i ka helu o nā lālā kaulahao pōkole (ʻo ka lōʻihi o ia mea e pili ana i ke ʻano comonomer) a no laila e kāohi i ka nui o ka resin. ʻO ke kiʻekiʻe o ka nui o ka comonomer, ʻo ka haʻahaʻa o ka nui o ka resin. Ma ke ʻano kūkulu, ʻokoʻa ka LLDPE mai ka LDPE ma ka helu a me ke ʻano o nā lālā, he mau lālā lōʻihi ko ka LDPE kaomi kiʻekiʻe, ʻoiai he mau lālā pōkole wale nō ko ka LDPE linear.

ka hana ʻana

Loaʻa i ka LDPE a me LLDPE ka rheology maikaʻi loa a i ʻole ke kahe heheʻe. ʻOi aku ka liʻiliʻi o ka ʻike shear o LLDPE ma muli o kona hoʻolaha kaumaha molekala haiki a me nā lālā kaulahao pōkole. I ka wā o ka shearing (e laʻa me ka extrusion), mālama ʻo LLDPE i kahi viscosity nui a no laila ʻoi aku ka paʻakikī o ka hana ʻana ma mua o LDPE me ka helu hoʻoheheʻe like. I ka extrusion, ʻo ka ʻike shear haʻahaʻa o LLDPE e ʻae ai i ka hoʻomaha wikiwiki ʻana o ke kaumaha o nā kaulahao molekala polymer, a no laila e emi ana ka ʻike o nā waiwai kino i nā loli i ka lakio pahū. I ka hoʻonui ʻana o ka heheʻe, loli ʻo LLDPE ma lalo o nā ʻano like ʻole. Loaʻa i ka maʻamau ka viscosity haʻahaʻa i ka wikiwiki. ʻO ia hoʻi, ʻaʻole ia e paʻakikī ke kīkoʻo ʻia e like me LDPE. Hoʻonui me ka helu deformation o ka polyethylene. Hōʻike ka LDPE i ka piʻi kupanaha o ka viscosity, kahi i hoʻokumu ʻia e ka entanglement o nā kaulahao molekala. ʻAʻole ʻike ʻia kēia hanana ma LLDPE no ka mea ʻo ka nele o nā lālā kaulahao lōʻihi ma LLDPE e mālama i ka polymer mai ka entanglement. He mea nui loa kēia waiwai no nā noi kiʻiʻoniʻoni lahilahi. No ka mea hiki i nā kiʻiʻoniʻoni LLDPE ke hana maʻalahi i nā kiʻiʻoniʻoni lahilahi me ka mālama ʻana i ka ikaika kiʻekiʻe a me ka paʻakikī. Hiki ke hōʻuluʻulu ʻia nā waiwai rheological o LLDPE e like me "paʻakikī i ka ʻokiʻoki" a me "palupalu i ka hoʻolōʻihi".