Chiyambi cha PBT

Polybutylene terephthalate (PBT mwachidule) ndi mndandanda wa ma polyesters, omwe amapangidwa ndi 1.4-pbt butylene glycol ndi terephthalic acid (PTA) kapena terephthalic acid ester (DMT) ndi polycondensation, ndipo amapangidwa ndi milky white kupyolera mu kusakaniza.Translucent to opaque, crystalline thermoplastic polyester resin.Pamodzi ndi PET, imadziwika kuti thermoplastic polyester, kapena polyester yodzaza.

PBT idapangidwa koyamba ndi wasayansi waku Germany P. Schlack mu 1942, kenako idapangidwa m'mafakitale ndi Celanese Corporation (tsopano Ticona) ndikugulitsidwa pansi pa dzina lamalonda la Celanex, lomwe linakhazikitsidwa mu 1970 ngati 30% ya pulasitiki yolimbitsa magalasi pansi pa dzina lamalonda X- 917, kenako idasinthidwa kukhala CELANEX.Eastman adayambitsa chinthu chokhala ndi magalasi owonjezera komanso opanda magalasi, pansi pa dzina la malonda Tenite (PTMT);m'chaka chomwechi, GE adapanganso chinthu chofanana ndi mitundu itatu yosalimbikitsidwa, yolimbikitsidwa komanso yozimitsa yokha.Pambuyo pake, opanga otchuka padziko lonse lapansi monga BASF, Bayer, GE, Ticona, Toray, Mitsubishi Chemical, Taiwan Shin Kong Hefei, Changchun Synthetic Resins, ndi Nanya Plastics adalowa motsatizana ndi kupanga, ndipo pali opanga oposa 30 padziko lonse lapansi.

Monga PBT ili ndi kukana kutentha, kukana kwa nyengo, kukana mankhwala, makhalidwe abwino a magetsi, kuyamwa kwa madzi otsika, gloss yabwino, yomwe imagwiritsidwa ntchito kwambiri pazida zamagetsi, zida zamagalimoto, makina, zinthu zapakhomo, ndi zina zotero, ndi zinthu za PBT ndi PPE, PC, POM, PA, ndi zina zonse pamodzi zimadziwika kuti mapulasitiki akuluakulu asanu akuluakulu a engineering.Kuthamanga kwa PBT crystallization, njira yabwino kwambiri yopangira jekeseni ndi kuumba jekeseni, njira zina ndi extrusion, kuwomba akamaumba, ❖ kuyanika, etc.

Kuchuluka kwazomwe mungagwiritse ntchito

Zipangizo zapakhomo (masamba opangira chakudya, zotsukira, mafani amagetsi, zipolopolo zowumitsira tsitsi, ziwiya za khofi, ndi zina), zida zamagetsi (ma switch, ma motor housing, mabokosi a fuse, makiyi a kiyibodi apakompyuta, ndi zina zotero), makampani amagalimoto (mafelemu owongolera nyali , mawindo a radiator grille, mapanelo thupi, zophimba magudumu, zitseko ndi mazenera zigawo, etc.).

Chemical ndi thupi katundu

PBT ndi imodzi mwazinthu zolimba kwambiri za engineering thermoplastics, ndi zida za semi-crystalline zokhazikika bwino pamakina, mphamvu zamakina, zida zamagetsi zamagetsi komanso kukhazikika kwamafuta.pbt ili ndi kukhazikika bwino pansi pazikhalidwe zachilengedwe.pbt ili ndi mphamvu yofooka kwambiri ya chinyezi.Kulimba kwamphamvu kwa PBT yosalimbitsa ndi 50 MPa, ndipo kulimba kwa magalasi amtundu wowonjezera wa fiber PBT ndi 170 MPa.Kuchuluka kwa magalasi owonjezera fiber kumapangitsa kuti zinthuzo zikhale zolimba.crystallization ya PBT imathamanga kwambiri, ndipo kuzizira kosagwirizana kumayambitsa kupindika.Kwa zinthu zomwe zili ndi galasi lowonjezera la fiber, kuchuluka kwa shrinkage m'njira yopitako kumatha kuchepetsedwa, ndipo kutsika kwapang'onopang'ono kolunjika sikuli kosiyana ndi zinthu zabwinobwino.Mlingo wocheperako wa zinthu za PBT wamba uli pakati pa 1.5% ndi 2.8%.Kuchepa kwa zinthu zomwe zili ndi 30% zowonjezera fiber fiber zili pakati pa 0.3% ndi 1.6%.

Makhalidwe a PBT jekeseni ndondomeko akamaumba

Njira ya polymerization ya PBT ndi yokhwima, yotsika mtengo komanso yosavuta kuumba ndi kukonza.Kuchita kwa PBT yosasinthika sikuli bwino, ndipo kugwiritsa ntchito kwenikweni kwa PBT kuyenera kusinthidwa, komwe, magalasi opangidwa ndi magalasi osinthidwa amakhala oposa 70% ya PBT.

1, PBT ili ndi malo osungunuka oonekera, malo osungunuka a 225 ~ 235 ℃, ndi crystalline chuma, crystallinity mpaka 40%.kukhuthala kwa PBT kusungunuka sikukhudzidwa ndi kutentha monga kupsinjika kwa shear, kotero, mu jekeseni wopangira jekeseni, kuthamanga kwa jekeseni pa PBT kusungunula fluidity kumaonekera.PBT mumkhalidwe wosungunuka wa madzi abwino, kukhuthala pang'ono, yachiwiri kwa nayiloni, popanga mosavuta "PBT yopangidwa ndi PBT ndi ya anisotropic, ndipo PBT ndiyosavuta kuipitsa pansi pa kutentha kwakukulu pokhudzana ndi madzi.

2, jekeseni akamaumba makina

Posankha makina opangira jekeseni wamtundu wa screw.Mfundo zotsatirazi ziyenera kuganiziridwa.

① Kuchuluka kwazinthu zomwe zimagwiritsidwa ntchito pazogulitsa kuyenera kuyendetsedwa pa 30% mpaka 80% ya kuchuluka kwa jakisoni wamakina omangira jekeseni.Sikoyenera kugwiritsa ntchito makina akuluakulu opangira jekeseni kuti apange mankhwala ang'onoang'ono.

② iyenera kusankhidwa ndi wononga pang'onopang'ono magawo atatu, kutalika mpaka m'mimba mwake chiyerekezo cha 15-20, psinjika chiŵerengero cha 2.5 mpaka 3.0.

③Ndi bwino kugwiritsa ntchito podzitsekera nokha ndi chipangizo chotenthetsera komanso chowongolera kutentha.

④Popanga PBT yoletsa moto, magawo ofunikira a makina opangira jakisoni ayenera kuthandizidwa ndi anti-corrosion.

3, Mankhwala ndi nkhungu kapangidwe

①Kukula kwazinthuzo sikuyenera kukhala konenepa kwambiri, ndipo PBT imakhudzidwa ndi notch, chifukwa chake malo osinthira monga mbali yoyenera yazinthu ayenera kulumikizidwa ndi ma arcs.

②Kupukutira kwa PBT yosasinthika ndi yayikulu, ndipo nkhungu iyenera kukhala ndi malo otsetsereka.

③Nkhungu iyenera kukhala ndi mabowo otulutsa mpweya kapena mipata yotulutsa mpweya.

④Diyace la chipata liyenera kukhala lalikulu.Ndibwino kuti mugwiritse ntchito othamanga ozungulira kuti muwonjeze kutengerapo kuthamanga.Mitundu yosiyanasiyana ya zipata ingagwiritsidwe ntchito ndipo othamanga otentha angagwiritsidwe ntchito.Dera la chipata liyenera kukhala pakati pa 0.8 ndi 1.0 * t, pomwe t ndi makulidwe a gawo la pulasitiki.Ngati zipata zomizidwa ndi madzi, m'mimba mwake osachepera 0.75mm akulimbikitsidwa.

⑤ Chikombolecho chiyenera kukhala ndi chipangizo chowongolera kutentha.Kutentha kwakukulu kwa nkhungu sikuyenera kupitirira 100 ℃.

⑥Pakuumba kwa PBT, pamwamba pa nkhunguyo kuyenera kukhala ndi chrome kuti zisawonongeke.

Kukhazikitsa magawo a process

Kuyanika chithandizo: Zinthu za PBT zimapangidwa mosavuta ndi hydrolyzed pa kutentha kwakukulu, kotero ziyenera kuumitsidwa musanakonze.Ndi bwino kuti ziume mu mpweya wotentha pa 120 ℃ kwa maola 4, ndi chinyezi ayenera kukhala osachepera 0.03%.

Kutentha kosungunuka: 225 ℃～275 ℃, kutentha kovomerezeka: 250 ℃.

Kutentha kwa nkhungu: 40 ℃ ~ 60 ℃ pazinthu zosalimbitsa.Kuziziritsa nkhungu kuyenera kukhala yunifolomu kuti muchepetse kupindika kwa mbali zapulasitiki, ndipo m'mimba mwake mwa njira yoziziritsira nkhungu ndi 12mm.

Kuthamanga kwa jekeseni: sing'anga (nthawi zambiri 50 mpaka 100MPa, yochuluka mpaka 150MPa).

Kuthamanga kwa jekeseni: Kuthamanga kwa jekeseni PBT kuzirala kumathamanga, kotero jekeseni wachangu ayenera kugwiritsidwa ntchito.Mlingo wofulumira kwambiri wa jakisoni uyenera kugwiritsidwa ntchito (chifukwa PBT imalimba mwachangu).

Liwiro la screw ndi kupanikizika kumbuyo: Kuthamanga kwa screw poumba PBT sikuyenera kupitirira 80r / min, ndipo nthawi zambiri kumakhala pakati pa 25 ndi 60r / min.Kuthamanga kumbuyo nthawi zambiri kumakhala 10% -15% ya kuthamanga kwa jekeseni.

Chidwi

①Kugwiritsa ntchito zinthu zobwezerezedwanso Chiŵerengero cha zinthu zobwezerezedwanso ndi zinthu zatsopano nthawi zambiri chimakhala 25% mpaka 75%.

②Kugwiritsa ntchito kutulutsa nkhungu Nthawi zambiri, palibe chotulutsa nkhungu chomwe chimagwiritsidwa ntchito, ndipo chotulutsa silicone chingagwiritsidwe ntchito ngati kuli kofunikira.

③Shutdown processing Nthawi yotseka ya PBT ili mkati mwa 30min, ndipo kutentha kumatha kutsitsidwa mpaka 200 ℃ mukatseka.Mukapanganso pambuyo pozimitsa kwa nthawi yayitali, zinthu zomwe zili mumgolo ziyenera kukhuthulidwa ndiyeno zatsopano ziyenera kuwonjezeredwa kuti zipangidwe bwino.

④ Pambuyo pokonza zinthu Nthawi zambiri, palibe chithandizo chofunikira, ndipo ngati kuli kofunikira, chithandizo cha 1 ~ 2h pa 120 ℃.

PBT special screw

Kwa PBT, yomwe ndi yosavuta kuwola, yokhudzidwa ndi kukakamizidwa ndipo ikufunika kuwonjezera ulusi wa galasi, phula lapadera la PBT limapanga kupanikizika kosasunthika ndipo limagwiritsa ntchito alloy iwiri kuti likhale lolimba kuti likhale lolimba la zinthu zomwe zili ndi galasi (PBT + GF).