Nhanganyaya kuPBT

Polybutylene terephthalate (PBT kwenguva pfupi) inoteedzana yepolyesters, iyo inogadzirwa ne 1.4-pbt butylene glycol uye terephthalic acid (PTA) kana terephthalic acid ester (DMT) ne polycondensation, uye inogadzirwa nemukaka muchena kuburikidza nekusanganiswa.Translucent kune opaque, crystalline thermoplastic polyester resin.Pamwe chete nePET, inozivikanwa pamwe chete se thermoplastic polyester, kana saturated polyester.

PBT yakatanga kugadzirwa nemusayendisiti wekuGermany P. Schlack muna 1942, ndokuzogadzirwa mumaindasitiri neCelanese Corporation (yava kunzi Ticona) uye yakatengeswa pasi pezita rekutengesa reCelanex, iro rakavambwa muna 1970 se30% yegirazi fiber yakasimbiswa pasi pezita rekutengesa X- 917, yakazoshandurwa kuita CELANEX.Eastman yakatanga chigadzirwa chine uye chisina girazi fiber reinforcement, pasi pezita rekutengesa Tenite (PTMT);mugore rimwe chetero, GE yakagadzirawo chigadzirwa chakafanana chine marudzi matatu asina kusimbiswa, akasimbiswa uye anozvidzima.Mushure mezvo, vagadziri vane mukurumbira pasi rose vakaita seBASF, Bayer, GE, Ticona, Toray, Mitsubishi Chemical, Taiwan Shin Kong Hefei, Changchun Synthetic Resins, uye Nanya Plastics vakapinda zvakatevedzana muzvikamu zvekugadzira, uye kune vanopfuura makumi matatu vagadziri pasi rese.

Sezvo PBT ine kupisa kwekupisa, kupikisa kwemamiriro ekunze, kushandiswa kwemakemikari, maitiro akanaka emagetsi, kunyura kwemvura shoma, kupenya kwakanaka, kushandiswa zvakanyanya mumidziyo yemagetsi, zvikamu zvemotokari, michina, zvigadzirwa zvemumba, nezvimwewo, uye PBT zvigadzirwa uye PPE, PC, POM, PA, etc. pamwe chete anozivikanwa seashanu makuru einjiniya mapurasitiki.PBT crystallization kumhanya, iyo yakanyatsokodzera kugadzirisa nzira ndeye jekiseni kuumba, dzimwe nzira ndeye extrusion, kuvhuvhuta kuumba, kupeta, nezvimwe.

Yakajairika application scope

Midziyo yemumba (chikafu chekugadzira bladhi, vacuum cleaner components, magetsi mafeni, hair dryer shells, midziyo yekofi, nezvimwewo), zvinhu zvemagetsi (switch, motor housings, fuse boxs, computer keyboard keys, etc.), indasitiri yemotokari (marambi anocheka mafuremu. , mahwindo eradiator grille, mapaneru emuviri, zvivharo zvemavhiri, magonhi nemahwindo, nezvimwe).

Kemikari uye zvinhu zvemuviri

PBT ndeimwe yeakaomesesa einjiniya thermoplastics, ndeye semi-crystalline zvinhu zvine kugadzikana kwakanaka kwemakemikari, simba remuchina, zvivakwa zvemagetsi uye kugadzikana kwekupisa.pbt ine kugadzikana kwakanaka pasi pemamiriro ekunze.pbt ine hunyoro hwakanyanya kunyura zvivakwa.Kusimba kwekusimba kwePBT isina kusimbiswa 50 MPa, uye kusimba kwegirazi fiber additive type PBT i170 MPa.yakawandisa girazi fiber additive inokonzeresa kuti zvinhu zviite brittle.iyo crystallization yePBT inokurumidza, uye kutonhora kusina kuenzana kunokonzeresa kubhenda deformation.Kune izvo zvinhu zvine girazi faibha yekuwedzera mhando, iyo shrinkage chiyero munzira yekuita inogona kuderedzwa, uye shrinkage mwero munzira yakatwasuka haina kusiyana kubva kune yakajairika zvinhu.The shrinkage rate yezvakawanda zvePBT zvinhu zviri pakati pe1.5% ne2.8%.Iyo shrinkage yezvinhu zvine 30% yegirazi fiber additives iri pakati pe0.3% ne1.6%.

Hunhu hwePBT jekiseni molding process

Iyo polymerization process yePBT yakakura, yakaderera mutengo uye iri nyore kuumba uye kugadzirisa.Kuitwa kwePBT isina kugadziriswa hakuna kunaka, uye kushandiswa kwePBT chaiyo kunofanira kuchinjwa, iyo, girasi fiber yakasimbiswa zvikwereti zvakagadziridzwa zvinodarika 70% yePBT.

1, PBT ine nzvimbo yekunyungudika iri pachena, nzvimbo yakanyunguduka inosvika 225 ~ 235 ℃, icrystalline material, crystallinity inosvika 40%.iyo viscosity yePBT yakanyunguduka haina kukanganiswa nekupisa sekunge kushushikana kweshear, saka, mukuumbwa kwejekiseni, kudzvanywa kwejekiseni paPBT kunyungudika fluidity kuri pachena.PBT mune yakanyungudutswa mamiriro emvura yakanaka, yakaderera viscosity, yechipiri chete kune naironi, mukuumba nyore kuitika "PBT yakaumbwa zvigadzirwa ndeye anisotropic, uye PBT iri nyore kudzikisira pasi pekushisa kwepamusoro pakusangana nemvura.

2, Jekiseni kuumba muchina

Pakusarudza screw type jekiseni rekuumba muchina.Pfungwa dzinotevera dzinofanira kufungwa nezvazvo.

① Huwandu hwezvinhu zvinoshandiswa muchigadzirwa zvinofanirwa kudzorwa pa30% kusvika 80% yeyakayerwa yakanyanya jekiseni vhoriyamu yemuchina wekuumba jekiseni.Hazvina kukodzera kushandisa jekiseni guru rekuumba muchina kugadzira zvigadzirwa zvidiki.

② inofanira kusarudzwa zvishoma nezvishoma-nhanho nhatu sikuruu, kureba kusvika kudhayamita reshiyo ye15-20, compression reshiyo ye2.5 kusvika 3.0.

③Zvakanakisa kushandisa yekuzvivharira nozzle ine kudziyisa uye tembiricha yekudzora mudziyo.

④Mukuumba murazvo unodzoreredza PBT, zvikamu zvakakodzera zvemushini wekuumba jekiseni unofanirwa kurapwa neanti-corrosion.

3、Chigadzirwa uye mold dhizaini

①Ukobvu hwezvigadzirwa hahufanire kunge hwakanyanya kukora, uye PBT inonzwa kune notch, saka nzvimbo dzekuchinja dzakadai sekona chaiyo yezvigadzirwa dzinofanirwa kubatanidzwa nearcs.

②Iyo yekuumba shrinkage yePBT isina kugadziriswa yakakura, uye mold inofanira kunge iine kumwe kutsetseka kwekudhirowa.

③Iyo mold inoda kuve yakashongedzerwa nemakomba ekuburitsa kana exhaust slots.

④Kuyera kwegedhi kunofanira kunge kwakakura.Inokurudzirwa kushandisa denderedzwa vamhanyi kuti uwedzere kudzvinyirira kuendeswa.Mhando dzakasiyana-siyana dzemagedhi dzinogona kushandiswa uye dzinopisa dzinomhanya dzinogona kushandiswawo.Iyo dhayamita yegedhi inofanirwa kunge iri pakati pe0.8 ne1.0 * t, uko t ndiko ukobvu hwechikamu chepurasitiki.Kana iri magedhi akanyura, dhayamita shoma ye 0.75mm inokurudzirwa.

⑤ Iyo mold inoda kuve neyakagadzirirwa tembiricha yekudzora mudziyo.Iyo yakanyanya tembiricha ye mold haifanirwe kudarika 100 ℃.

⑥Pakuumbwa kwePBT yegiredhi retardant retardant, iyo mold inofanira kunge yakapetwa chrome kudzivirira kuora.

Setting ye process parameters

Kuomesa kurapwa: PBT zvinhu zviri nyore hydrolyzed pakupisa kwakanyanya, saka inoda kuomeswa isati yagadziriswa.Inokurudzirwa kuoma mumhepo inopisa pa 120 ℃ kwemaawa mana, uye hunyoro hunofanira kunge huri pasi pe0.03%.

Kunyunguduka tembiricha: 225℃～275℃, inokurudzirwa tembiricha: 250℃.

Mold tembiricha: 40℃～60℃ yezvinhu zvisina kusimbiswa.Kutonhodza moudhi kunofanirwa kunge kuri yunifomu kudzikisa kubhenda kwezvikamu zvepurasitiki, uye dhayamita yakakurudzirwa ye mold inotonhorera chiteshi chiteshi ndeye 12mm.

Jekiseni pressure: yepakati (kazhinji 50 kusvika 100MPa, yakawanda kusvika 150MPa).

Jekiseni kumhanya: jekiseni mwero PBT kutonhora kumhanya inokurumidza, saka kukurumidza jekiseni chiyero chinofanira kushandiswa.Muyero wejekiseni wekukurumidza unobvira unofanirwa kushandiswa (nekuti PBT inosimba nekukurumidza).

Screw kumhanya uye kumashure kumanikidza: Iyo screw speed yekuumba PBT haifanirwe kudarika 80r/min, uye kazhinji iri pakati pe25 ne60r/min.Iyo yekumashure dzvinyiriro inowanzo 10% -15% yekumanikidza jekiseni.

Attention

①Kushandiswa kwezvinhu zvakadzokororwa Huyero yezvinhu zvakadzokororwa kune zvitsva zvinowanzoita 25% kusvika 75%.

②Kushandiswa kwe mold release agent Kazhinji, hapana mold release agent inoshandiswa, uye silicone mold release agent inogona kushandiswa kana zvichidiwa.

③Shutdown kugadzirisa Nguva yekuvhara yePBT iri mukati me30min, uye tembiricha inogona kudzikiswa kusvika ku200℃ kana yadzima.Paunenge uchigadzira zvakare mushure mekuvharwa kwenguva refu, zvinhu zviri mudhiramu zvinofanirwa kudururwa uyezve zvinhu zvitsva zvinofanirwa kuwedzerwa kuti zvive zvakajairika.

④ Post-kugadzirisa zvigadzirwa Kazhinji, hapana kurapwa kunodiwa, uye kana zvichidikanwa, 1 ~ 2h kurapwa pa120 ℃.

PBT yakakosha sikuru

Kune PBT, iri nyore kuora, inonzwa kumanikidzwa uye inoda kuwedzera girazi fiber, iyo PBT yakakosha sikuru inoburitsa yakatsiga kudzvanywa uye inoshandisa kaviri alloy kuvandudza kupfeka kuramba kwezvinhu negirazi fiber (PBT + GF).