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Nhanganyaya kune Polyolefins uye Firimu Extrusion

Polyolefins, kirasi yezvigadzirwa zvemacromolecular zvakagadzirwa kubva kuolefin monomers senge ethylene uye propylene, ndiwo mapurasitiki anogadzirwa zvakanyanya uye anoshandiswa pasi rose. Kuwanda kwavo kunobva mukusanganiswa kwakasarudzika kwezvivakwa, zvinosanganisira mutengo wakaderera, kugona kwakanakisa, kugadzikana kwemakemikari, uye hunhu hunogoneka. Pakati pemashandisirwo akasiyana e polyolefins, zvigadzirwa zvemafirimu zvine chinzvimbo chepamusoro, zvichishandira mabasa akakosha mukurongedza chikafu, zvekufukidzira zvekurima, kurongedza mumaindasitiri, zvigadzirwa zvekurapa nehutsanana, uye zvinhu zvemazuva ese zvevatengi. Mapolyolefin anonyanya kushandiswa pakugadzira mafirimu anosanganisira polyethylene (PE) - inosanganisira Linear Low-Density Polyethylene (LLDPE), Low-Density Polyethylene (LDPE), uye High-Density Polyethylene (HDPE) - uye polypropylene (PP).

Kugadzirwa kwemafirimu epololefin kunonyanya kutsamira pane tekinoroji yeextrusion, neBlown Firimu Extrusion uye Cast Firimu Extrusion ari iwo maviri makuru maitiro.

1. Yakaputika Firimu Extrusion Process

Blown film extrusion ndiyo imwe yenzira dzakatekeshera dzekugadzira polyolefin mafirimu. Iyo yakakosha musimboti inosanganisira kuburitsa polima yakanyungudutswa yakatwasuka kumusoro kuburikidza neanular kufa, kugadzira yakatetepa-yakavakirwa tubular parison. Mushure mezvo, mweya wakamanikidzwa unopinzwa mukati mechechi iyi, zvichiita kuti ipinde mububble rine dhayamita rakakura zvakanyanya kupfuura iro rekufa. Sezvo bubble richikwira, rinotonhodzwa nechisimba uye rinosimbiswa nemhete yekunze yemhepo. Bubble rakatonhodzwa rinobva radhirika neseti yenip rollers (kazhinji kuburikidza nefuremu inodonha kana A-frame) uye yozodhonzwa nema traction rollers isati yakuvadzwa pamupumburu. Iyo firimu yakafemerwa maitiro anowanzo kuburitsa mafirimu ane biaxial orientation, zvichireva kuti anoratidza chiyero chakanaka chemichina mumativi ese emuchina (MD) uye inochinjika nzira (TD), senge simba rekusimba, kuramba kubvarura, uye simba rekukanganisa. Firimu ukobvu uye michina zvivakwa zvinogona kudzorwa nekugadzirisa kuputika-up reshiyo (BUR - chiyero chebubble dhayamita kusvika kufa dhayamita) uye dhirowa-pasi reshiyo (DDR - chiyero chekutora-up kumhanya kune extrusion kumhanya).

2. Cast Film Extrusion Process

Cast firimu extrusion ndiyo imwe yakakosha kugadzirwa kwemafirimu epololefin, anonyanya kukodzera kugadzira mafirimu anoda epamusoro ekuona zvinhu (semuenzaniso, kujeka kwepamusoro, kupenya kwepamusoro) uye kuenzana kwakakura kwakafanana. Mukuita uku, iyo polima yakanyungudutswa inoburitswa yakatwasuka kuburikidza nefurati, slot-mhando T-die, ichigadzira yunifomu yakanyungudutswa web. Dandemutande iri rinobva rakweverwa pamusoro peimwe kana anopfuura anomhanya-mhanya, akatonhodzwa mukati mechill rolls. Iyo inonyungudika inoomesa nekukurumidza kana yasangana neinotonhora roll pamusoro. Mafirimu eCast anowanzo kuve neakanakisa optical zvimiro, kunzwa kwakapfava, uye yakanaka kupisa-sealability. Kudzora kwakaringana pamusoro pefa lip gap, chill roll tembiricha, uye kumhanya kwekutenderera kunobvumira kurongeka kwakaringana kwekukora kwefirimu uye kunaka kwepasi.

Pamusoro 6 Polyolefin Firimu Extrusion Matambudziko

Zvisinei nekukura kwe tekinoroji yeextrusion, vagadziri vanogara vachisangana nematambudziko ekugadzirisa mukugadzirwa kwemafirimu epololefin, kunyanya pavanenge vachivavarira kubuda kwepamusoro, kushanda zvakanaka, mageji matete, uye kana vachishandisa marezeni matsva ekuita kwepamusoro. Idzi nyaya hadzingokanganisa kugadzikana kwekugadzirwa chete asiwo dzinokanganisa zvakananga chigadzirwa chekupedzisira mhando uye mutengo. Matambudziko makuru anosanganisira:

1. Melt Fracture (Sharkskin): Ichi ndicho chimwe chezvakanyanya kukanganisa mu polyolefin film extrusion. Macroscopically, inotaridza seperiodic transverse ripples kana isingaite hutsinye hwepamusoro pafirimu, kana mumatambudziko akaomarara, zvakanyanya kutaurwa kukanganisa. Melt fracture inonyanya kuitika kana shear rate yepolymer inonyunguduka ichibuda mufa yakadarika kukosha kwakakosha, zvichitungamira kune stick-slip oscillations pakati pemadziro efa uye kuwanda kunyungudika, kana iyo yekuwedzera kushushikana pakubuda kwefa kunodarika simba rekunyungudika. Ichi chikanganiso chinokanganisa zvakanyanya maitiro emufirimu (kujeka, kupenya), kutsvedzerera kwepamusoro, uye kunogonawo kushatisa mashandiro ayo uye zvipingamupinyi.

2. Die Drool / Die Build-up: Izvi zvinoreva kuunganidzwa zvishoma nezvishoma kwezvigadzirwa zvepolymer degradation, zvikamu zvishoma zvehuremu hwema molecular, zvinowedzerwa zvisina kuparadzirwa zvakanaka (semuenzaniso, pigments, antistatic agents, slip agents), kana gels kubva kune resin pamucheto wemuromo wefa kana mukati mekufa. Aya madhipoziti anogona kuvharika panguva yekugadzira, achisvibisa iyo firimu pamusoro uye kukonzera kuremara senge gels, mitsetse, kana makwara, zvichizokanganisa kutaridzika kwechigadzirwa uye kunaka. Muzviitiko zvakakomba, kufa kwekuvaka-up kunogona kuvharira kubuda kwekufa, zvichitungamira mukusiyana kwegeji, kubvarura firimu, uye pakupedzisira kumanikidza kuvharwa kwemitsara yekugadzira yekuchenesa kufa, zvichikonzera kurasikirwa kukuru mukugadzirwa kwekugadzira uye kutambisa zvinhu.

3. High Extrusion Pressure uye Fluctuation: Pasi pemamwe mamiriro ezvinhu, kunyanya kana uchigadzira ma-high-viscosity resin kana kushandisa maduku maduku ekufa, kudzvinyirira mukati me extrusion system (kunyanya pamusoro we extruder uye kufa) inogona kuva yakanyanyisa. Kudzvinyirirwa kwepamusoro hakungowedzere kushandiswa kwesimba chete asiwo kunoisa njodzi kuhupenyu hurefu hwemidziyo (semuenzaniso, screw, mbiya, kufa) uye chengetedzo. Uyezve, kusagadzikana kuchinjika mukumanikidzwa kweextrusion kunokonzeresa mutsauko mukunyungudika kubuda, zvichitungamira kune isina-uniform firimu ukobvu.

4. Kuburikidza Nenguva Yakaganhurirwa: Kudzivirira kana kudzikisira nyaya dzakaita senge kunyunguduka uye kufa kuvaka-up, vagadziri vanowanzomanikidzwa kuderedza extruder sikururu kumhanya, nekudaro vachidzikamisa kubuda kwemutsara wekugadzira. Izvi zvinokanganisa zvakanangana nekugadzira uye mutengo wekugadzira pachikamu chimwe nechimwe chechigadzirwa, zvichiita kuti zviome kuzadzisa zvinodiwa pamusika zvemafirimu akakura, ane mutengo wakaderera.

5. Kuoma muGauge Control: Kusagadzikana mukunyunguduka kwekunyunguduka, kugoverwa kwekushisa kusina kufanana mukufa, uye kufa-up-up zvose zvinogona kuita kuti kuve nekusiyana kwemukobvu wefirimu, zvose zvakachinjika uye kureba. Izvi zvinokanganisa firimu rinotevera kugadzirisa kuita uye magumo ekushandisa maitiro.

6. Yakaoma Resin Shanduko: Paunenge uchishandura pakati pemhando dzakasiyana kana mamakisi e polyolefin resins, kana pakuchinja mavara masterbatches, zvinhu zvakasara kubva kune yapfuura kumhanya kazhinji zvakaoma kuchenesa zvachose kubva kune extruder uye kufa. Izvi zvinotungamira mukusanganiswa kwezvinhu zvekare uye zvitsva, kugadzira shanduko yezvinhu, kuwedzera nguva yekuchinja, uye kuwedzera mitengo yezvinhu.

Aya matambudziko akajairwa ekugadzirisa anomanikidza kuedza kwevagadziri vemafirimu epololefin kuti vawedzere kunaka kwechigadzirwa nekubudirira kwekugadzira, uye zvakare zvinoisa zvipingamupinyi pakutorwa kwezvinhu zvitsva uye nzira dzepamusoro dzekugadzirisa. Naizvozvo, kutsvaga mhinduro dzinoshanda dzekukunda matambudziko aya kwakakosha pakusimudzira uye kune hutano kusimudzira kweindasitiri yese yepololefin firimu extrusion.

Solutions for Polyolefin Film Extrusion Process: Polymer Processing Aids (PPAs)

Polymer Processing Aids (PPAs) zviwedzere zvinoshanda zvine kukosha kwacho kuri mukuvandudza rheological hunhu hwepolymer inonyungudika panguva yekuwedzeredza uye kugadzirisa kupindirana kwavo nenzvimbo dzemidziyo, nekudaro kukunda kwakasiyana-siyana kuomerwa kwekugadzirisa uye kuwedzera kunaka kwekugadzira uye kunaka kwechigadzirwa.

1. Fluoropolymer-based PPAs

Kemikari Yakaumbwa uye Hunhu: Aya pari zvino ndiwo anonyanya kushandiswa, tekinoroji akakura, uye anoratidza anoshanda kirasi yePPAs. Iwo anowanzo mahomopolymers kana copolymers akavakirwa pafluoroolefin monomers akadai sevinylidene fluoride (VDF), hexafluoropropylene (HFP), uye tetrafluoroethylene (TFE), ine fluoroelastomers iri iyo inomiririra zvakanyanya. Cheni dzemamorekuru dzeaya maPPA dzakapfuma mu-high-bond-energy, low-polarity CF bond, iyo inopa yakasarudzika physicochemical properties: yakanyanya kuderera pamusoro pesimba (zvakafanana nepolytetrafluoroethylene/Teflon®), kugadzikana kwekupisa kwakanyanya, uye kusagadzikana kwemakemikari. Nekutsoropodza, fluoropolymer PPAs kazhinji anoratidza kusaenderana neasiri-polar polyolefin matrices (sePE, PP). Kusapindirana uku ndicho chinhu chakakosha chinodiwa kuti vafambe zvakanaka kuenda kunzvimbo dzesimbi dzefa, uko vanogadzira dhizaini yekuzora.

Zvinomiririrwa Zvigadzirwa: Mabhureki anotungamira mumusika wepasi rose wefluoropolymer PPAs anosanganisira Chemours 'Viton™ FreeFlow™ akatevedzana uye 3M's Dynamar™ akatevedzana, ayo anoraira yakakosha musika. Pamusoro pezvo, mamwe mamakisi efluoropolymer kubva kuArkema (Kynar® akatevedzana) neSolvay (Tecnoflon®) anoshandiswawo se, kana kuti zvikamu zvakakosha mu, PPA maumbirwo.

2. Silicone-based Processing Aids (PPAs)

Kemikari Yakarongeka uye Hunhu: Iwo ekutanga anoshanda zvikamu mukirasi ino yePPAs mapolysiloxanes, anowanzo kunzi silicones. Iyo polysiloxane musana ine alternating silicon uye maatomu eokisijeni (-Si-O-), ine organic mapoka (kazhinji methyl) akasungirirwa kumaatomu esilicon. Iyi yakasarudzika mamorekuru dhizaini inopa silicone zvinhu zvine yakaderera kwazvo pamusoro petension, yakanyanya kugadzikana yekupisa, yakanaka kuchinjika, uye isina-inonamatira zvimiro kune zvakawanda zvinhu. Zvakafanana nefluoropolymer PPAs, silicone-based PPAs inoshanda nekutamira kune simbi nzvimbo dzemichina yekugadzirisa kugadzira dhizaini yekuzora.

Zvishandiso Zvishandiso: Kunyangwe fluoropolymer PPAs ichitonga iyo polyolefin firimu extrusion chikamu, silicone-based PPAs inogona kuratidza yakasarudzika mabhenefiti kana kugadzira synergistic mhedzisiro kana ichishandiswa mune chaiwo mamiriro ekushandisa kana pamwe chete nemamwe masisitimu eresin. Semuyenzaniso, anogona kutariswa sezvikumbiro zvinoda kuderera zvakanyanya coefficients yekukwesha kana painodiwa chimiro chepamusoro pachigadzirwa chekupedzisira.

Kutarisana neFluoropolymer Bans kana PTFE Supply Challenges?

Gadzirisa Polyolefin Firimu Extrusion Matambudziko nePFAS-Mahara PPA Solutions-SILIKE's Fluorine Yemahara Polymer additives

SILIKE inotora maitiro ekuita neayo SILIMER akatevedzana zvigadzirwa, inopa hunyanzviPFAS-yemahara polymer kugadzirisa aids (PPAs) Iyi yakazara chigadzirwa mutsara inoratidza 100% yakachena PFAS-isina maPPA,fluorine-isina PPA Polymer additives,uyePFAS-yemahara & fluorine-isina PPA masterbatches.Bykubvisa kudiwa kwe fluorine additives, izvi zvinobatsira zvekugadzirisa zvinosimudzira zvakanyanya maitiro ekugadzira LLDPE, LDPE, HDPE, mLLDPE, PP, uye akasiyana polyolefin firimu extrusion maitiro. Ivo vanoenderana neazvino mirau yezvakatipoteredza uku vachiwedzera kugadzirwa kwakanaka, kuderedza nguva, uye kuvandudza huwandu hwechigadzirwa. SILIKE's PFAS-yemahara PPAs inounza mabhenefiti kuchigadzirwa chekupedzisira, kusanganisira kubviswa kwekunyunguduka kutsemuka (sharkskin), yakakwidziridzwa kutsvedzerera, uye yemhando yepamusoro yepamusoro.

Kana iwe uchinetsekana nekukanganisa kwefluoropolymer kurambidzwa kana kushomeka kwePTFE mune yako polymer extrusion maitiro, SILIKE inopa.dzimwe nzira dzefluoropolymer PPAs/PTFE, PFAS-yemahara yekuwedzera yekugadzira mafirimuizvo zvakagadzirirwa kusangana nezvido zvako, pasina shanduko inodiwa.