Litaba

Kenyelletso ea Polyolefins le Film Extrusion

Polyolefin, sehlopha sa lisebelisoa tsa macromolecular tse entsoeng ho tsoa ho olefin monomers joalo ka ethylene le propylene, ke lipolasetiki tse hlahisoang haholo le tse sebelisoang ho fetisisa lefatšeng ka bophara. Ho ata ha tsona ho bakoa ke motsoako o ikhethang oa thepa, ho kenyeletsoa litšenyehelo tse tlase, ts'ebetso e ntle haholo, botsitso bo ikhethang ba lik'hemik'hale, le litšobotsi tse loketseng tsa 'mele. Har'a lisebelisoa tse fapaneng tsa polyolefin, lihlahisoa tsa lifilimi li na le boemo bo ka sehloohong, li sebeletsa mesebetsi ea bohlokoa ho pakang lijo, likoahelo tsa temo, liphutheloana tsa indasteri, lihlahisoa tsa bongaka le tsa bohloeki, le thepa ea letsatsi le letsatsi ea bareki. Li-resin tse tloaelehileng tsa polyolefin tse sebelisoang bakeng sa tlhahiso ea lifilimi li kenyelletsa polyethylene (PE) - e kenyeletsang Linear Low-Density Polyethylene (LLDPE), Low-Density Polyethylene (LDPE), le High-Density Polyethylene (HDPE) - le polypropylene (PP).

Ho etsoa ha lifilimi tsa polyolefin haholo-holo ho itšetlehile ka theknoloji ea extrusion, 'me Blown Film Extrusion le Cast Film Extrusion e le mekhoa e 'meli ea mantlha.

1. Ts'ebetso ea Extrusion ea Filimi e Blown

Blown film extrusion ke e 'ngoe ea mekhoa e atileng haholo ea ho hlahisa lifilimi tsa polyolefin. Molao-motheo oa mantlha o kenyelletsa ho phahamisetsa polima e qhibilihisitsoeng ka holimo ho ea holimo ka selemo sa selemo, ho etsa parishe e nang le mabota a masesaane. Ka mor'a moo, moea o hatelitsoeng o kenngoa ka hare ho parison ena, e leng se etsang hore o kene ka har'a bubble e nang le bophara bo boholo ho feta ea lefu. Ha bubble e nyoloha, e pholile ka likhoka ebe e tiisoa ke selikalikoe sa moea se ka ntle. Bubble e pholisitsoeng e ntan'o putlama ke sete ea li-nip rollers (hangata ka foreimi e putlang kapa A-frame) ebe e huloa ke lirolara tse hohelang pele e lemetsoa holim'a moqolo. Ts'ebetso ea filimi e fokang hangata e hlahisa lifilimi tse nang le biaxial orientation, ho bolelang hore li bonts'a ho leka-lekana ha thepa ea mochini ho tataiso ea mochini (MD) le tsela e fapaneng (TD), joalo ka matla a thata, ho hanyetsa meokho, le matla a ts'usumetso. Botenya ba filimi le thepa ea mochini e ka laoloa ka ho lokisa karo-karolelano ea ho phatloha (BUR - karo-karolelano ea bubble bophara ba bophara ba ho shoa) le tekanyo ea ho theoha (DDR - karo-karolelano ea lebelo la ho nka-ho ea ho lebelo la extrusion).

2. Cast Film Extrusion Process

Cast film extrusion ke ts'ebetso e 'ngoe ea bohlokoa ea tlhahiso bakeng sa lifilimi tsa polyolefin, tse loketseng haholo ho etsa lifilimi tse hlokang thepa ea boleng bo holimo (mohlala, ho hlaka ho hoholo, khanya e phahameng) le botenya bo bongata bo ts'oanang. Ts'ebetsong ena, polima e qhibilihisitsoeng e phahamisoa ka mokhoa o tšekaletseng ka T-die e bataletseng, ea mofuta oa slot, e etsa tepo e ts'oanang e qhibilihisitsoeng. Tepo ena e huleloa ka potlako holim'a leqhubu le le leng kapa a mangata a lebelo le phahameng, a pholileng ka hare. Melt e tiea kapele ha e kopana le sebaka se batang sa roll. Lifilimi tsa Cast ka kakaretso li na le lisebelisoa tse ntle tsa optical, maikutlo a bonolo, le ho thibela mocheso hantle. Taolo e nepahetseng holim'a lekhalo la molomo oa die, mocheso oa chill roll, le lebelo la ho potoloha li lumella taolo e nepahetseng ea botenya ba filimi le boleng ba bokaholimo.

Mathata a kaholimo ho 6 a Polyolefin Film Extrusion

Ho sa tsotellehe khōlo ea theknoloji ea extrusion, bahlahisi ba atisa ho kopana le letoto la mathata a ts'ebetsong tlhahisong e sebetsang ea lifilimi tsa polyolefin, haholo-holo ha ba leka ho fumana lihlahisoa tse phahameng, tse sebetsang hantle, litekanyo tse fokolang, le ha ba sebelisa li-resin tse ncha tse sebetsang hantle. Litaba tsena ha li ame feela botsitso ba tlhahiso empa hape li ama ka ho toba boleng ba sehlahisoa sa ho qetela le litšenyehelo. Mathata a mantlha a kenyelletsa:

1. Qhibiliha Fracture (Sharkskin): Ena ke e 'ngoe ea liphoso tse atileng ka ho fetisisa polyolefin filimi extrusion. Ka makhroscopic, e bonahala joalo ka maqhubu a nako le nako kapa sebaka se mahoashe ka mokhoa o sa tloaelehang filiming, kapa maemong a matla, ho khopama ho hlakileng haholoanyane. Qhibiliha fracture haholo-holo ha lebelo la ho kuta ea polymer qhibiliha exiting lefu feta bohlokoa bohlokoa, e isang ho thupa-slip oscillations pakeng tsa lerako la shoa le ho qhibiliha ka bongata, kapa ha khatello ea kelello e atolositsoeng ho tsoa lefung e feta matla a ho qhibiliha. Phoso ena e senya haholo thepa ea optical ea filimi (ho hlaka, gloss), boreleli ba holim'a metsi, hape e ka senya thepa ea eona ea mechine le ea thibelo.

2. Die Drool / Die Build-up: Sena se bolela ho bokella butle-butle ha lihlahisoa tsa polymer degradation, likaroloana tse tlaase tsa boima ba molek'hule, li-additives tse sa qhalakantsoeng hantle (mohlala, li-pigments, li-antistatic agents, li-slip agents), kapa li-gel tse tsoang ho resin metseng ea molomo oa die kapa ka har'a sekoti. Li-deposit tsena li ka ikhula nakong ea tlhahiso, tsa silafatsa bokaholimo ba filimi le ho baka likoli joalo ka li-gel, li-streaks kapa likhopo, ka hona, li ama ponahalo le boleng ba sehlahisoa. Maemong a boima, ho hakanngoa ha lefu ho ka thibela tsela ea ho tsoa, ​​​​e lebisang ho phapano ea likhakanyo, ho taboha ha lifilimi, 'me qetellong ea qobella ho koaloa ha mohala oa tlhahiso bakeng sa tlhoekiso ea lefu, ho baka tahlehelo e kholo ts'ebetsong ea tlhahiso le tšenyo ea thepa e tala.

3. Khatello e Phahameng ea Extrusion le Fluctuation: Tlas'a maemo a itseng, haholo-holo ha u sebetsana le li-resin tse nang le li-viscosity tse phahameng kapa ho sebelisa likheo tse nyenyane tsa ho shoa, khatello e ka hare ho tsamaiso ea extrusion (haholo-holo hloohong ea extruder le ho shoa) e ka ba e phahameng haholo. Khatello e phahameng ha e eketse tšebeliso ea matla feela empa e boetse e beha kotsi ho nako e telele ea lisebelisoa (mohlala, screw, barrel, die) le polokeho. Ho feta moo, ho feto-fetoha ho sa tsitsang ha khatello ea extrusion ka ho toba ho baka phapang ea tlhahiso ea ho qhibiliha, e lebisang ho botenya ba filimi e sa tšoaneng.

4. Nako e Lekanyelitsoeng: Ho thibela kapa ho fokotsa litaba tse kang ho qhibiliha ha ho qhibiliha le ho bokellana ha lefu, hangata bahlahisi ba qobelloa ho fokotsa lebelo la extruder screw, kahoo ba fokotsa tlhahiso ea mohala oa tlhahiso. Sena se ama ka kotloloho katleho ea tlhahiso le litšenyehelo tsa tlhahiso yuniti ka 'ngoe ea sehlahisoa, ho etsa hore ho be thata ho fihlela litlhoko tsa 'maraka bakeng sa lifilimi tse kholo, tse theko e tlase.

5. Bothata ba Taolo ea Gauge: Ho se tsitse ha phallo ea ho qhibiliha, ho ajoa ha mocheso o sa tsitsang ho pholletsa le lefu, le ho haha ​​​​mafu kaofela ho ka tlatsetsa ho fapana ha botenya ba filimi, ka bobeli le ka nako e telele. Sena se ama ts'ebetso e latelang ea ts'ebetso ea filimi le litšobotsi tsa tšebeliso ea ho qetela.

6. Phetoho e Thata ea Resin: Ha u fetola pakeng tsa mefuta e sa tšoaneng kapa limaraka tsa li-resin tsa polyolefin, kapa ha u fetola li-masterbatches tsa mebala, lisebelisoa tse setseng ho tloha nakong e fetileng hangata ho thata ho li hloekisa ka ho feletseng ho tsoa ho extruder le ho shoa. Sena se lebisa ho kopanngoeng ha lisebelisoa tsa khale le tse ncha, ho hlahisa thepa ea phetoho, ho lelefatsa nako ea phetoho, le ho eketseha ha likhahla.

Liphephetso tsena tse tloaelehileng tsa ts'ebetso li thibela boiteko ba baetsi ba lifilimi tsa polyolefin ho ntlafatsa boleng ba sehlahisoa le katleho ea tlhahiso, hape li beha litšitiso ho amoheloa ha thepa e ncha le mekhoa e tsoetseng pele ea ho e lokisa. Ka hona, ho batla litharollo tse sebetsang tsa ho hlola mathata ana ho bohlokoa bakeng sa nts'etsopele e tsitsitseng le e phetseng hantle ea indasteri eohle ea polyolefin extrusion.

Litharollo tsa Polyolefin Film Extrusion Process: Polymer Processing Aids (PPAs)

Polymer Processing Aids (PPAs) ke li-additives tse sebetsang tseo boleng ba tsona bo ka sehloohong bo leng ho ntlafatseng boitšoaro ba rheological ea polymer e qhibilihisang nakong ea extrusion le ho fetola tšebelisano ea bona le bokaholimo ba lisebelisoa, kahoo ba hlola mathata a mangata a ho sebetsa le ho ntlafatsa katleho ea tlhahiso le boleng ba sehlahisoa.

1. Li-PPA tse thehiloeng ho Fluoropolymer

Sebopeho sa Lik'hemik'hale le Litšobotsi: Hona joale tsena ke lihlopha tse sebelisoang ka ho fetisisa, tse hōlileng ka ho fetisisa tsa theknoloji, 'me li bonahala li sebetsa hantle ka ho fetisisa tsa li-PPA. Hangata ke li-homopolymers kapa copolymers tse ipapisitseng le fluoroolefin monomers joalo ka vinylidene fluoride (VDF), hexafluoropropylene (HFP), le tetrafluoroethylene (TFE), 'me fluoroelastomers ke eona e emelang haholo. Liketane tsa limolek'hule tsa li-PPA tsena li na le matla a phahameng a matla, a tlaase a polarity CF, a fanang ka thepa e ikhethang ea physicochemical: matla a tlaase haholo a holim'a metsi (ho tšoana le polytetrafluoroethylene / Teflon®), botsitso bo botle ba mocheso, le ho se sebetse ha lik'hemik'hale. Hantle-ntle, li-PPA tsa fluoropolymer ka kakaretso li bonts'a tšebelisano e mpe le matrices a polyolefin a seng polar (joaloka PE, PP). Ho se lumellane hona ke ntho e ka sehloohong e hlokahalang bakeng sa ho falla ha bona ka mokhoa o atlehang ho ea libakeng tsa tšepe tsa lefu, moo ba etsang seaparo se matla sa lubricating.

Lihlahisoa tsa Moemeli: Lihlahisoa tse hlahelletseng 'marakeng oa lefats'e bakeng sa li-fluoropolymer PPA li kenyelletsa letoto la Chemours' Viton™ FreeFlow™ le letoto la 3M's Dynamar™, le laelang karolo e kholo ea mmaraka. Ho feta moo, limaraka tse ling tsa fluoropolymer ho tloha ho Arkema (Kynar® series) le Solvay (Tecnoflon®) le tsona li sebelisoa e le, kapa ke likarolo tsa bohlokoa, litlhahlobo tsa PPA.

2. Silicone-based Processing Aids (PPAs)

Sebopeho sa Lik'hemik'hale le Litšobotsi: Likarolo tse ka sehloohong tse sebetsang sehlopheng sena sa li-PPA ke li-polysiloxane, tseo hangata li bitsoang silicones. Mokokotlo oa polysiloxane o na le silicon e fapaneng le liathomo tsa oksijene (-Si-O-), tse nang le lihlopha tse phelang (hangata methyl) tse khomaretsoeng liathomong tsa silicon. Sebopeho sena se ikhethang sa limolek'hule se fana ka lisebelisoa tsa silicone tse nang le tsitsipano e tlase haholo ea holim'a metsi, botsitso bo botle ba mocheso, ho tenyetseha hantle, le thepa e sa khomaretseng lintho tse ngata. Ho tšoana le li-PPA tsa fluoropolymer, li-PPA tse thehiloeng ka silicone li sebetsa ka ho fallela libakeng tsa tšepe tsa lisebelisoa tsa ho sebetsa ho etsa lera la ho tlotsa.

Likarolo tsa Ts'ebeliso: Leha li-PPA tsa fluoropolymer li laola lefapha la polyolefin extrusion, li-PPA tse thehiloeng ho silicone li ka bonts'a melemo e ikhethang kapa tsa theha litlamorao tse kopaneng ha li sebelisoa maemong a itseng a ts'ebeliso kapa li kopane le lisebelisoa tse itseng tsa resin. Mohlala, li ka nahanoa bakeng sa lits'ebetso tse hlokang likhokahano tse tlase haholo tsa khohlano kapa moo ho batloang sebopeho se ikhethileng bakeng sa sehlahisoa sa ho qetela.

Ho tobana le Lithibelo tsa Fluoropolymer kapa Liphephetso tsa Phepelo ea PTFE?

Rarolla Liqholotso tsa Polyolefin Extrusion Film ka Litharollo tsa PFAS-Mahala tsa PPA- SILIKE's Fluorine Free Polymer additives

SILIKE e nka mokhoa o ts'oanelang ka lihlahisoa tsa eona tsa SILIMER, tse fanang ka mekhoa e metleLithuso tsa ho sebetsana le li-polymer tse sa lefelloeng tsa PFAS (PPAs). Mohala ona o felletseng oa sehlahisoa o na le li-PPA tsa mahala tsa PFAS tse 100%,Lisebelisoa tsa PPA Polymer tse se nang fluorine, lePFAS-mahala & fluorine-mahala PPA masterbatches.Kaho felisa tlhoko ea li-additives tsa fluorine, lithuso tsena tsa ts'ebetso li ntlafatsa haholo ts'ebetso ea tlhahiso ea LLDPE, LDPE, HDPE, mLLDPE, PP, le mekhoa e fapaneng ea extrusion ea lifilimi tsa polyolefin. Li hokahana le melaoana ea morao-rao ea tikoloho ha li ntse li matlafatsa ts'ebetso ea tlhahiso, li fokotsa nako, le ho ntlafatsa boleng ba sehlahisoa ka kakaretso. Li-PPA tse se nang PFAS tsa SILIKE li tlisa melemo ho sehlahisoa sa ho qetela, ho kenyeletsoa ho felisoa ha fracture e qhibilihang (letlalo la lishaka), boreleli bo ntlafalitsoeng, le boleng ba boleng bo holimo.

Haeba u ntse u loana le tšusumetso ea lithibelo tsa fluoropolymer kapa khaello ea PTFE lits'ebetsong tsa hau tsa polymer extrusion, SILIKE e fana kamefuta e meng ho feta fluoropolymer PPAs/PTFE, Li-additives tsa mahala tsa PFAS bakeng sa tlhahiso ea lifilimitse etselitsoeng ho fihlela litlhoko tsa hau, ntle le liphetoho tse hlokahalang.