Ukwenza Ukuthi Ukuhlelwa Kwakho Kwe-Blown Film Kufanele Kukhethwe Ngokwesilinganiso Ngamathuba Ama-Plastic (LLDPE, LDPE, HDPE)

Izinsizakalo zesibonelo sesiqondiso: Ukuthi i-LLDPE, i-LDPE, ne-HDPE ziyakhuluma njani kusukela kweblown film extrusion

Ukuhambisana kwesifunda, i-MI, nokuphambuka kwebhobhuli: Kungani i-LLDPE ibuyela phambili kumsebenzi wokubhala isithuthu

Ukuzinza kwamabhamuza ekukhiqizeni ifilimu yokwelula yomshini ophefumulelwe kuncike emandleni okucibilika kanye ne-Melt Index (MI). Ngenkathi i-LDPE's long-chain branching inikeza amandla okuncibilika aphezulu kanye nefasitela lokucubungula elixolelayo, i-LLDPE iyisinqumo esiyinhloko sefilimu yokwelula esebenza kahle ngenxa yokuqina kwayo okuphezulu, ukumelana nokuqhekeka, nokuqina. Isakhiwo sayo sezinhlayiyana esinolayini sinikeza amandla okucibilika aphansi kodwa lokhu kulawulwa ngempumelelo ngokukhetha amabanga anezinani le-MI phakathi kuka-0.52.0 g/10 min. I-MI ephansi yandisa ukuhlangana kwamaketanga, ithuthukise ukuzinza kwe-bubble ngaphandle kokudela ukucubungula. Kuye kwaboniswa ukuthi amafomula e-LLDPE alungiselelwe anciphisa ukuhluka kwe-film gauge ngo-15% uma kuqhathaniswa ne-LDPE engashintshiwe ekusetshenzisweni okufanayo, okuthuthukisa ngqo isivuno nokuvumelana kwemishini.

I-crystallinity ne-freeze-line dynamics: Imiphumela yokulawulwa kwe-gauge nokucaca okubonakalayo

Ukukhanya kuyisibonelo sokugcina umsebenzi wokufika emva kokuhlwa—futhi ngakho ukubaluleka kwesilinganiso sesithembiso nesilinganiso sesibonelo. Ukukhanya kwe-HDPE (kusho kusukela ku-80%) kuyenza ukuhlwa kushisa kakhulu nokufika emva kokuhlwa okuphelele, okunqamuka ukubaluleka kwesilinganiso sesithembiso sokubhekana nesilinganiso sesibonelo. Ukubhekana kwe-LDPE kuyenza ukukhanya kushisa, kwenza ukufika emva kokuhlwa okungafanele, okuncongatha ukubaluleka kwesilinganiso sesithembiso futhi ukuthola ukubaluleka okuphelele. Kusuka emasheeni e-machine stretch film, i-LLDPE iyasebenzisa indlela eyodwa: ukukhanya okusemthwakathini kuyavumela abasebenzi ukuphakamisa ukufika emva kokuhlwa—ukuvumela izihlangu zokubhekana ukuzilahlela kabusha emva kokuhlwa—ngakho ukunciphisa ukubaluleka kwesibonelo ngaphezu kwe-20% lapho kubhalwa ngokuhle kwe-cooling.

Izinkulungwane zomsebenzi oziningi zokwenza i-machine stretch film efanele

Ukuhlaziyisa isikhathi sokudla (190–230°C) ukuze ubalancise ukubaluleka kwesikhathi sokudla nesilinganiso sesiphumo

Ukukhulisa ukuthi isikhathi sokugqamisa kwezinkundla zokugqamisa kuyisisekelo sokubaluleka kokubaluleka kwesilinganiso nesibonelo sokubaluleka kwesilinganiso. Isilinganiso sesikhathi sokugqamisa se-190–230°C sivumela ukuzimela okujwayelekile kwezinkundla zokugqamisa ngokuvimbela izinkinga zokuphakama okuzosetha izinkinga zokuguquka kwezilinganiso. Kuma-LDPE, ukusebenza kwi-ndawo eyisiphakade yalesilinganiso sivumela ukuphakama kokugqamisa futhi kusivumela ukubaluleka kokubaluleka kwesilinganiso sokubhubha. LDPE isebenza kahle kwezinkundla ezincinci ukuze kuvikeke ukugqamisa kwesikhathi, ngakho-ke HDPE ikhomba ukukhulisa kakhulu ukuze kuvikeke ukubaluleka kwesilinganiso phambi kwesikhathi sokugqamisa. Ukukhulisa kwezinkundla zokugqamisa ngokuhambisana kuyavumela ukuvikeka kwesilinganiso sokugqamisa, ukunciphisa ukwakha kwezinkundla zokugqamisa, nokuthuthukisa isikhathi sokusebenza—ngaphandle kokunqula ukukhulisa ukukhulisa kwezinkundla zokugqamisa. Lokhu kuyisibonelo sokukhulisa isikhathi sokugqamisa sokuvikeka ukubaluleka kwesilinganiso sokubhubha, okuyisibonelo sokubaluleka kwesilinganiso nokubaluleka kwesilinganiso sokubaluleka kwesilinganiso.

Ukukhulisa isilinganiso sokubhubha (BUR) nokukhulisa isikhathi sokubhubha sokufaka isilinganiso sokubhubha nokubaluleka kwesilinganiso sokubhubha

I-BUR nezintando zokuphakamisa izinkomba zokufika kwezinkambu ziyizinto eziningi ezingenela ukuthi i-molecular orientation nezindlela zokusebenza zokugcina kwezinkamba. I-BUR yoku-2:1 ku-3:1 iyathuthukisa ukuthintana kwesikhathi sokubuka kwezinkamba—okuyisisekelo sokugcina izilwanyana—ngakholwa ukuthi ukuphakamisa izinkomba zokufika kwezinkamba kusinika isikhathi esingaphezulu sokuzimela kwezinkamba zokubuka, okuthuthukisa ukuthi izinkamba zokubuka ziyahlukana ngokulinganayo futhi kususa ukuthi kunezinkinga zokuzimela. Kodwa, ukuphakamisa kakhulu izinkomba zokufika kwezinkamba kungasiza ukuthi izinkamba ziyadlula futhi kungasiza ukuthi kunezinkinga zokuhlukaniswa kwezinkamba. Abengineya bavumela lezi zinto ngokuhlanganisa: i-LLDPE ibonakala ngezinkinga eziningi zokubuka kwezinkamba futhi ngezinkinga eziningi zokuphakamisa izinkomba zokufika kwezinkamba ngokwesibonelo sokuthi inikezela ukuthi izinkamba ziyabona ngokuphelele; i-HDPE inqoba ukuthi kubekwe ukuthi i-BUR ibe ngaphansi kwe-2.5:1 futhi izinkomba zokufika kwezinkamba zibe phansi futhi zibe zilungile ukuze kungabi nesikhundla sokudlula. Ukubona ngokushesha kwenza ukuthi izinkamba zokugcina ziyathola ukuthi kunezinkinga zokuthintana, ukuthi kunezinkinga zokuthintana ngokwesibonelo, nokuthi kunezinkinga zokuthintana ngokwesibonelo—lezi zinto ziyisisekelo sokuthi izinkamba ziyathola ukuthi kunezinkinga zokuthintana ngokwesibonelo, ukuthi kunezinkinga zokuthintana ngokwesibonelo, nokuthi kunezinkinga zokuthintana ngokwesibonelo.

Ukuthatha isikhathi sokuchitha futhi ukuphakamisa izinkomba zokufika kwezinkamba kwezinye izinhlobo zezinkamba zokubuka

Ukuzwela kokupholisa kwe-LDPE kuqhathaniswa ne-HDPE yokuqhakaza okusheshayo: Ukwehlisa ukuhluka kwe-gauge

Ukusabalala okukhulu kwesisindo samangqamuzana e-LDPE kwakha uhla olubanzi lokuthamba, okwenza ibhola libe liguquguquka kahle ngaphezu komugqa weqhwa. Lokhu kuzwela kokupholisa kudinga ukuphohla kancane kancane, okufana nomngcele, okuvame ukufezwa ngokunciphisa ijubane lendandatho yomoya nokukhulisa umugqa weqhwa ngo-10% ukuze kuzinze ibhola ngaphambi kokuqina. Ngokuphambene, i-HDPE i-crystallization esheshayo ngaphansi kuka ~ 130 °C ivala noma yikuphi ukungafani okukhona ekuphumeni kwe-die. Ukuze kulungiswe lokhu, opharetha basebenzisa ukuyekelela okuqinile kwezikhala ze-die (± 2%) futhi bagcine umugqa oqinile, ozinzile weqhwa ku-200300 mm ngaphezu kwe-die. Izindandatho zomoya ezinemilomo emibili ziqinisekisa ukupholisa okuqhubekayo kwe-radial, kuvimbela ukuhluka kwe-gauge ngaphansi kuka-3%. Lezi zindlela ezihlukile zibonisa impendulo yokushisa engaphakathi kwe-resin ngayinye futhi zibalulekile ekugcineni ukusebenza kwefilimu yokwelula ezinhlotsheni ze-polyolefin.

Ukubeka isiphumo sokusebenza nokuhlelisa kwezinhloso zokusebenzisa i-stretch film

Ukuhlanza kwakho, ubukhulu bekuphuma kwezinye izinto, nokubheka kwakho: Ukulandela ukwahluka kwezinkambo ngokwesikhundla sokugcina umsindo

Ukugcina umthwalo ungaphakathi kudinga ukuqina okulinganiselayo, ukumelana nokudabuka, nokumunca amandla. I-HDPE inikeza i-modulus ephakeme ye-secant (> 800 MPa), inciphisa ukugoba ngaphansi komthwalo ohlala njalokodwa ukudabuka kwayo kukhawulela ukumelana nomthelela: amanani ajwayelekile okuwa kwe-dart ewela ngaphansi kuka-100 g, futhi amandla okudwengula e-Elmendorf ngokuvamile I-LLDPE inikeza ukumelana nokugqwala okuphawulekayoamandla okugqwala kancane ngokuvamile adlula i-15 J/mmngenxa yokusabalalisa kwayo isisindo samangqamuzana esincane nokufakwa kwe-comonomer elawulwayo, okukhuthaza ukuguqulwa kwe-ductile nokusakazeka kwamandla. Ukuze kuhloswe izinhlelo zokusebenza ezifuna imithwalo esindayo noma enobunjwa obungajwayelekile, izakhiwo ezinezendlalelo eziningi (isb., i-HDPE noma i-LDPE core enezikhumba ze-LLDPE) zihlanganisa ukuqina nokuqina ngempumelelo kunefilimu ye-monolayer

Ukucaca, ukuvaleka nokuqina: Kungani i-LLDPE ilawula ifilimu yokwelula yomshini ophefumulelwe esebenza kahle

LLDPE yisibonelo esihlukile sokufuna ukusetyenziswa kwezikhathi zokuphakama zokubhala isifilm sokugcina ngokuphakama, ngoba yinombolo yezindlela ezihlukene zokubona, ukugcina ngokuchitha, nokugcina ngokuzenzakalelayo. Izigaba zesibonelo se-LLDPE esisebenzisa i-hexene noma i-octene zifika emaphakathini okubona okungafani nge-2%, okunconywa ukusondeza amabharikhozi nokubona ngokwesibonelo—ngaphandle kwe-LDPE, okwesibonelo kuyasebenza ngaphezulu kwe-5% yokubona. Ukuncane kwakho kwe-crystallinity kwenza ukuthi ukugcina ngokuchitha kwenzeke kusheshile futhi ukugcina kwenzeke ngemvume yamandla angafani ngezinye izinhlobo, okuyisidingo sokugcina ngokushesha kwezinhlobo zokuphakama zokuphakama zokuphakama zokuphakama. Kuvumelwe ukuthi i-LLDPE ibuka ukugcina ngokuzenzakalelayo (50–100 g/cm) ngaphandle kokusetshenziswa kwamadoda okugcina, ngokusebenzisa ukuthi ukuthi umkhawulo wokugcina wakho uyasebenza ngokushesha futhi ukuthi ukuthi umkhawulo wokugcina wakho uyasebenza ngokushesha—ukuthi ukuthi umkhawulo wokugcina wakho uyasebenza ngokushesha kuyasebenza ngokushesha kwezinhlobo zokuphakama zokuphakama zokuphakama. Lezi zinhlobo zokuhlanganisa zinconywa ukuthi izifilm ezingaphansi kanye nezinkulu ziyasebenza ngokushesha futhi ziyagcina ukuthi izinto ziyagcina ngokushesha kwezinhlobo zokuphakama zokuphakama zokuphakama.

Imibuzo Evame Ukubuzwa

Yini umbingelelo wezivinini zokugcina (MI) kwezinhlobo zokubhala isifilm?

Izivalelo se-Melt Index (MI) sisebenza kakhulu ekuvumelaneni kwemvelo yokuqondisa nokubulawa kokuphuma kwesithuthi sokufakwa. Izivalelo eziphansi ze-MI zihlela ukugxilwa kweziqu, zihlela ukubulawa ngaphandle kokukhula kwezinhlelo zokusebenza. Lokhu kubalulekile kakhulu kwezifomula ze-LLDPE, ozikwazi ukuzisiza ngamathuba amahle we-MI ukuze bafanele kakhulu.

Ukuthi ukusobala kuyaphinda kuthintana nendlela yokubulawa kweziqu zezopolime ezahlukene?

Ukusobala kuyaphinda kuthintana nokubulawa kweziqu nokubulawa kweziqu. Izopolime ezinjenge-HDPE ezenzima ukusobala kuzoba kusha, futhi isithuthi se-LDPE esinamagqabi asihlukene asibulawa ukusobala, okuhlela ukulawula kahle nokubona kahle. I-LLDPE inombolo yokuquketha, isinika izindaba zokubona kanye nokubulawa kweziqu.

Ngani ukulawula kwesikhathi sekhalini kubalulekile kwenziwa kwezithuthi zokubulawa?

Ukukhanyisa ukukhokhela kwezinkambo zokugcina isikhathi esifanayo nokuphatha ukuguqula kwesithunzi. Amapolimeya amahlanu ayidinga izikhathi ezithile ukuze kuvikeke ukugcina kwezinkambo noma ukubhala kabusha phambi kwesikhathi, ngakho-ke kubuyisela ubukhulu bokugcina kwezinkambo nezinkambo zokuziphatha.

Yini amaph advantages okusebenzisa amasithrakcha amaningi emvelo ekusetshenziseni kwemvelo yokuthwala?

Amasithrakcha amaningi ayilungiselela amapolimeya amahlanu ukuze akhululeke ngokuphelele. Isibonelo, amakhophi we-HDPE noma we-LDPE asinika ubukhulu, ngakho-ke amasithrakcha we-LLDPE asinika ubukhulu bekhona nokukhanya kokuthwala, okwenza ukuthi isithrakcha sibe yilokho okuhle kakhulu kumalume omkhulu noma amalume angafane.

Kungani we-LLDPE ibhekwa ngokuphelele kumalume okuphelele yokuthwala?

We-LLDPE ibhekwa ngokuphelele ngokukhanya kakhulu kwayo, ukukhokhela kwezinkambo zokugcina, nokukhanya kokuthwala. Kusinika ukuthwala okuphelele okuphansi, kunciphisa ukusebenzisa izinto, nokuphatha ubukhulu bekho ngaphandle kokusebenzisa izinto eziningi, okwenza ukuthi kube yilokho okuhle kakhulu kumalume wokuphatha amathuba ehlakweni.