Njira ndi Mitundu ya Polyethylene Yopangira
(1) Polyethylene Yochepa (LDPE)
Pamene kuchuluka kwa mpweya kapena ma peroxides akuwonjezeredwa ngati zoyambitsa ku ethylene yoyera, yokanikizidwa kufika pafupifupi 202.6 kPa, ndikutenthedwa kufika pafupifupi 200°C, ethylene imasintha kukhala polyethylene yoyera, yonga sera. Njira imeneyi nthawi zambiri imatchedwa njira yopanikizika kwambiri chifukwa cha momwe ntchito ikuyendera. Polyethylene yomwe imachokera imakhala ndi kuchuluka kwa 0.915–0.930 g/cm³ ndipo kulemera kwake kumakhala pakati pa 15,000 ndi 40,000. Kapangidwe kake ka mamolekyu ndi nthambi zambiri komanso kosasunthika, kofanana ndi mawonekedwe "ofanana ndi mtengo", omwe amachititsa kuti ikhale yochepa, motero imatchedwa polyethylene yocheperako.
(2) Polyethylene Yokhala ndi Kuchuluka Kwapakati (MDPE)
Njira yogwiritsira ntchito mphamvu yapakati imaphatikizapo kupanga polymer ya ethylene pansi pa mlengalenga wa 30-100 pogwiritsa ntchito zitsulo zotchedwa metal oxide catalysts. Polyethylene yomwe imachokera imakhala ndi kuchuluka kwa 0.931–0.940 g/cm³. MDPE ingapangidwenso posakaniza polyethylene yapamwamba kwambiri (HDPE) ndi LDPE kapena kudzera mu copolymerization ya ethylene ndi ma comonomers monga butene, vinyl acetate, kapena acrylates.
(3) Polyethylene Yokhala ndi Kachulukidwe Kakakulu (HDPE)
Pansi pa kutentha ndi kupanikizika kwabwinobwino, ethylene imapangidwa ndi polymer pogwiritsa ntchito ma catalyst ogwira ntchito bwino kwambiri (mankhwala a organometallic opangidwa ndi alkylaluminum ndi titanium tetrachloride). Chifukwa cha ntchito yayikulu yothandiza, polymerization reaction imatha kuchitika mwachangu pamavuto otsika (0–10 atm) ndi kutentha kochepa (60–75°C), motero amatchedwa njira yotsika ya kupanikizika. Polyethylene yomwe imachokera ili ndi kapangidwe ka molekyulu kopanda nthambi, komwe kumathandizira kuti ikhale ndi kuchuluka kwakukulu (0.941–0.965 g/cm³). Poyerekeza ndi LDPE, HDPE imawonetsa kukana kutentha kwambiri, mphamvu zamakanika, komanso kukana kupsinjika kwa chilengedwe.
Katundu wa Polyethylene
Polyethylene ndi pulasitiki yoyera ngati mkaka, yofanana ndi sera, yowonekera pang'ono, zomwe zimapangitsa kuti ikhale yotetezera kutentha komanso yophimba mawaya ndi zingwe. Ubwino wake waukulu ndi monga:
(1) Makhalidwe abwino kwambiri amagetsi: kukana kutentha kwambiri komanso mphamvu ya dielectric; permittivity yochepa (ε) ndi dielectric loss tangent (tanδ) pamitundu yosiyanasiyana ya ma frequency, yokhala ndi kudalira kochepa kwa ma frequency, zomwe zimapangitsa kuti ikhale dielectric yoyenera kwambiri pa zingwe zolumikizirana.
(2) Makhalidwe abwino a makina: osinthasintha koma olimba, komanso okana kusintha kwa masinthidwe.
(3) Kukana kwambiri kukalamba kwa kutentha, kufooka kwa kutentha kochepa, komanso kukhazikika kwa mankhwala.
(4) Kukana bwino madzi ndi chinyezi chochepa; kukana kutenthetsa nthawi zambiri sikuchepa ikamizidwa m'madzi.
(5) Popeza si chinthu chofanana ndi polar, chimakhala ndi mpweya wochuluka wolowa, ndipo LDPE imakhala ndi mpweya wolowa kwambiri pakati pa mapulasitiki.
(6) Mphamvu yokoka yochepa, yonse ili pansi pa 1. LDPE imadziwika kwambiri pa pafupifupi 0.92 g/cm³, pomwe HDPE, ngakhale kuti ndi yochuluka kwambiri, ili pafupi 0.94 g/cm³ yokha.
(7) Makhalidwe abwino ogwiritsira ntchito: zosavuta kusungunula ndi kusungunula pulasitiki popanda kuwola, zimazizira mosavuta kukhala mawonekedwe, ndipo zimathandiza kuwongolera bwino mawonekedwe ndi kukula kwa zinthu.
(8) Zingwe zopangidwa ndi polyethylene ndi zopepuka, zosavuta kuyika, komanso zosavuta kuzithetsa. Komabe, polyethylene ilinso ndi zovuta zingapo: kutentha kochepa kofewa; kuyaka, kutulutsa fungo lofanana ndi parafini ikawotchedwa; kukana kupsinjika kwa chilengedwe komanso kukana kukwawa. Chisamaliro chapadera chikufunika mukamagwiritsa ntchito polyethylene ngati chotetezera kutentha kapena chophimba cha zingwe zam'madzi kapena zingwe zomwe zimayikidwa m'malo otsetsereka otsetsereka.
Mapulasitiki a Polyethylene a Mawaya ndi Zingwe
(1) Pulasitiki ya Polyethylene Yoteteza Zinthu Zonse
Yopangidwa ndi polyethylene resin ndi ma antioxidants okha.
(2) Pulasitiki ya Polyethylene Yosagwedezeka ndi Nyengo
Makamaka zimapangidwa ndi polyethylene resin, ma antioxidants, ndi carbon black. Kukana kwa nyengo kumadalira kukula kwa tinthu, kuchuluka kwake, ndi kufalikira kwa carbon black.
(3) Pulasitiki ya Polyethylene Yolimbana ndi Kupsinjika kwa Zachilengedwe
Imagwiritsa ntchito polyethylene yokhala ndi chiŵerengero cha kusungunuka kwa madzi pansi pa 0.3 ndi kufalikira kochepa kwa kulemera kwa mamolekyulu. Polyethylene ingathenso kulumikizidwa kudzera mu kuwala kapena njira za mankhwala.
(4) Pulasitiki ya Polyethylene Yoteteza Mphamvu Kwambiri
Kuteteza chingwe chamagetsi amphamvu kwambiri kumafuna pulasitiki ya polyethylene yoyera kwambiri, yowonjezerapo ma voltage stabilizers ndi ma extruders apadera kuti apewe kupangika kwa void, kuletsa kutuluka kwa resin, ndikuwonjezera kukana kwa arc, kukana kukokoloka kwa magetsi, komanso kukana korona.
(5) Pulasitiki ya Polyethylene Yosapanga Magesi
Yopangidwa powonjezera kaboni wakuda woyendetsa ku polyethylene, nthawi zambiri pogwiritsa ntchito tinthu tating'onoting'ono tating'onoting'ono ta kaboni wakuda kwambiri.
(6) Thermoplastic Low-Smoked Zero-Halogen (LSZH) Polyolefin Cable Compound
Chomerachi chimagwiritsa ntchito utomoni wa polyethylene ngati maziko ake, kuphatikizapo zinthu zoletsa moto zopanda halogen, zinthu zoletsa utsi, zinthu zolimbitsa kutentha, zinthu zoyambitsa bowa, ndi zinthu zopaka utoto, zomwe zimapangidwa kudzera mu kusakaniza, pulasitiki, ndi pelletization.
Polyethylene Yolumikizidwa (XLPE)
Pogwiritsa ntchito mphamvu yamagetsi amphamvu kwambiri kapena zinthu zolumikizirana, kapangidwe ka molekyulu ya polyethylene kamasanduka kapangidwe ka magawo atatu (network), zomwe zimapangitsa kuti zinthu za thermoplastic zikhale thermoset. Zikagwiritsidwa ntchito ngati chotenthetsera,XLPEimatha kupirira kutentha kosalekeza mpaka 90°C ndi kutentha kwafupipafupi kwa 170–250°C. Njira zolumikizirana zimaphatikizapo kulumikizana kwa thupi ndi mankhwala. Kulumikizana kwa radiation ndi njira yeniyeni, pomwe mankhwala olumikizirana kwambiri ndi DCP (dicumyl peroxide).
Nthawi yotumizira: Epulo-10-2025