Taw qhia rau PBT

Polybutylene terephthalate (PBT luv luv) yog ib tug series ntawm polyesters, uas yog ua los ntawm 1.4-pbt butylene glycol thiab terephthalic acid (PTA) los yog terephthalic acid ester (DMT) los ntawm polycondensation, thiab yog ua los ntawm milky dawb los ntawm kev sib tov.Translucent rau opaque, crystalline thermoplastic polyester cob.Ua ke nrog PET, nws yog hu ua thermoplastic polyester, los yog saturated polyester.

PBT yog thawj zaug tsim los ntawm German tus kws tshawb fawb P. Schlack hauv xyoo 1942, tom qab ntawd tsim kev lag luam los ntawm Celanese Corporation (tam sim no Ticona) thiab ua lag luam raws li lub npe lag luam Celanex, uas tau tsim tawm hauv xyoo 1970 ua 30% iav fiber reinforced yas raws li lub npe lag luam X- 917, tom qab ntawd hloov mus rau CELANEX.Eastman tau tsim cov khoom lag luam nrog thiab tsis muaj iav fiber ntau, raws li lub npe lag luam Tenite (PTMT);nyob rau hauv tib lub xyoo, GE kuj tsim ib yam khoom zoo sib xws nrog peb ntau yam ntawm unreinforced, reinforced thiab self-extinguishing.Tom qab ntawd, cov tuam txhab muaj npe nrov hauv ntiaj teb xws li BASF, Bayer, GE, Ticona, Toray, Mitsubishi Chemical, Taiwan Shin Kong Hefei, Changchun Synthetic Resins, thiab Nanya Plastics tau nkag mus rau qib ntau lawm, thiab muaj ntau tshaj 30 lub tuam txhab thoob ntiaj teb.

Raws li PBT muaj cov cua kub tsis kam, huab cua tsis kam, tshuaj tiv thaiv, hluav taws xob zoo, tsis tshua muaj dej nqus, zoo gloss, dav siv hauv cov khoom siv hluav taws xob, khoom siv tsheb, tshuab, khoom siv hauv tsev, thiab lwm yam, thiab PBT cov khoom thiab PPE, PC, POM, PA, thiab lwm yam ua ke hu ua tsib qhov loj loj engineering plastics.PBT crystallization ceev, txoj kev tsim nyog tshaj plaws yog kev txhaj tshuaj molding, lwm txoj kev yog extrusion, tshuab molding, txheej, thiab lwm yam.

Ib qho kev thov Scope

Cov khoom siv hauv tsev (cov khoom siv ua zaub mov, cov khoom siv lub tshuab nqus tsev, cov kiv cua hluav taws xob, lub tshuab ziab plaub hau, cov khoom siv kas fes, thiab lwm yam), cov khoom siv hluav taws xob (switches, motor homes, fuse boxes, computer keyboard keys, etc.), automotive industry (lamp trim frames. , radiator grille qhov rais, lub cev panels, log npog, qhov rooj thiab qhov rais Cheebtsam, thiab lwm yam).

Tshuaj thiab lub cev muaj zog

PBT yog ib qho nyuaj tshaj plaws engineering thermoplastics, nws yog ib tug semi-crystalline khoom nrog zoo heev tshuaj stability, txhua yam muaj zog, hluav taws xob rwb thaiv tsev zog thiab thermal stability.pbt muaj kev ruaj ntseg zoo nyob rau hauv ib puag ncig.pbt muaj qhov tsis muaj zog noo noo zoo heev.Lub zog tensile ntawm tsis muaj zog PBT yog 50 MPa, thiab lub zog tensile ntawm iav fiber ntau hom PBT yog 170 MPa.iav fiber ntau additive yuav ua rau cov khoom ua nkig.Lub crystallization ntawm PBT yog ceev heev, thiab tsis sib xws txias yuav ua rau khoov deformation.Rau cov khoom siv nrog iav fiber ntau additive hom, lub shrinkage tus nqi nyob rau hauv tus txheej txheem kev taw qhia yuav txo tau, thiab lub shrinkage tus nqi nyob rau hauv lub ntsug kev taw qhia yog yeej tsis txawv ntawm cov khoom ib txwm.Lub shrinkage tus nqi ntawm PBT cov ntaub ntawv yog nruab nrab ntawm 1.5% thiab 2.8%.Lub shrinkage ntawm cov ntaub ntawv uas muaj 30% iav fiber ntau additives yog nruab nrab ntawm 0.3% thiab 1.6%.

Cov yam ntxwv ntawm PBT txhaj tshuaj molding txheej txheem

Cov txheej txheem polymerization ntawm PBT yog cov paub tab, tus nqi qis thiab yooj yim rau pwm thiab txheej txheem.Kev ua tau zoo ntawm PBT tsis hloov kho tsis zoo, thiab daim ntawv thov tiag tiag ntawm PBT yuav tsum tau hloov kho, ntawm cov iav fiber ntau hloov kho cov qib suav nrog ntau dua 70% ntawm PBT.

1, PBT muaj qhov pom tseeb melting point, melting point ntawm 225 ~ 235 ℃, yog crystalline khoom, crystallinity mus txog 40%.Lub viscosity ntawm PBT yaj tsis cuam tshuam los ntawm qhov kub thiab txias ntau npaum li kev ntxhov siab shear, yog li ntawd, hauv kev txhaj tshuaj molding, kev txhaj tshuaj siab ntawm PBT yaj fluidity yog pom tseeb.PBT nyob rau hauv lub xeev molten ntawm zoo fluidity, tsawg viscosity, thib ob tsuas yog nylon, nyob rau hauv molding yooj yim tshwm sim "PBT molded cov khoom yog anisotropic, thiab PBT yog ib qho yooj yim degrade nyob rau hauv high kub nyob rau hauv kev sib cuag nrog dej.

2 、 Txhaj tshuaj molding tshuab

Thaum xaiv cov ntsia hlau hom txhaj tshuaj molding tshuab.Cov ntsiab lus hauv qab no yuav tsum xav txog.

① Tus nqi ntawm cov khoom siv hauv cov khoom yuav tsum raug tswj ntawm 30% mus rau 80% ntawm qhov ntsuas siab tshaj plaws ntawm cov tshuaj txhaj tshuaj molding tshuab.Nws tsis tsim nyog siv lub tshuab txhaj tshuaj loj loj los tsim cov khoom me me.

② yuav tsum tau xaiv nrog ib tug maj mam peb-theem ntsia hlau, ntev rau txoj kab uas hla ntawm 15-20, compression ratio ntawm 2.5 mus rau 3.0.

③Nws yog qhov zoo tshaj plaws los siv nws tus kheej-locking nozzle nrog cua sov thiab ntsuas kub.

④ Hauv molding nplaim taws retardant PBT, qhov cuam tshuam ntawm lub tshuab txhaj tshuaj molding yuav tsum tau kho nrog kev tiv thaiv corrosion.

3 、 Khoom thiab pwm tsim

① Lub thickness ntawm cov khoom yuav tsum tsis txhob tuab heev, thiab PBT yog rhiab heev rau lub notch, yog li ntawd lub transitional chaw xws li lub kaum sab xis ntawm cov khoom yuav tsum tau txuas nrog arcs.

② Lub molding shrinkage ntawm unmodified PBT yog loj, thiab cov pwm yuav tsum muaj ib tug tej yam nqes hav ntawm demoulding.

③ Cov pwm yuav tsum tau nruab nrog lub qhov tso pa tawm lossis qhov tso tawm.

④ Txoj kab uas hla ntawm lub qhov rooj yuav tsum loj.Nws raug nquahu kom siv cov kev sib tw khiav los ua kom lub zog hloov pauv.Ntau hom rooj vag tuaj yeem siv tau thiab cov neeg ua haujlwm kub kub kuj tseem siv tau.Lub rooj vag txoj kab uas hla yuav tsum nyob nruab nrab ntawm 0.8 thiab 1.0 * t, qhov twg t yog lub thickness ntawm cov yas.Nyob rau hauv cov rooj vag submerged, qhov tsawg kawg nkaus txoj kab uas hla ntawm 0.75mm yog pom zoo.

⑤ Cov pwm yuav tsum tau nruab nrog kev tswj qhov kub thiab txias.Qhov siab tshaj plaws ntawm cov pwm yuav tsum tsis pub tshaj 100 ℃.

⑥ Rau cov nplaim hluav taws kub qib PBT molding, qhov saum npoo ntawm cov pwm yuav tsum yog chrome plated los tiv thaiv corrosion.

Kev teeb tsa cov txheej txheem parameter

Kev kho kom qhuav: PBT cov khoom yog yooj yim hydrolyzed ntawm qhov kub thiab txias, yog li nws yuav tsum tau qhuav ua ntej ua.Nws raug nquahu kom qhuav hauv huab cua kub ntawm 120 ℃ rau 4 teev, thiab cov av noo yuav tsum tsawg dua 0.03%.

Melting kub: 225 ℃ ~ 275 ℃, pom zoo kub: 250 ℃.

Pwm kub: 40 ℃ ~ 60 ℃ rau cov khoom siv tsis muaj zog.Pwm cua txias yuav tsum zoo ib yam los txo qhov khoov deformation ntawm cov yas qhov chaw, thiab qhov pom zoo txoj kab uas hla ntawm pwm txias kab noj hniav channel yog 12 hli.

Txhaj tshuaj siab: nruab nrab (feem ntau 50 txog 100MPa, siab tshaj plaws rau 150MPa).

Kev txhaj tshuaj nrawm: Tus nqi txhaj tshuaj PBT txias ceev yog ceev, yog li yuav tsum tau siv qhov kev txhaj tshuaj sai dua.Kev txhaj tshuaj sai tshaj plaws yuav tsum tau siv (vim tias PBT solidifies sai).

Screw ceev thiab rov qab siab: Cov ntsia hlau ceev rau molding PBT yuav tsum tsis pub tshaj 80r / min, thiab feem ntau yog nyob nruab nrab ntawm 25 thiab 60r / min.Lub siab rov qab yog feem ntau 10% -15% ntawm kev txhaj tshuaj.

Nco ntsoov

① Kev siv cov khoom siv rov ua dua Qhov piv ntawm cov khoom siv rov ua dua rau cov khoom tshiab feem ntau yog 25% mus rau 75%.

② Kev siv cov pwm tso tawm feem ntau, tsis muaj pwm tso tawm tus neeg sawv cev, thiab silicone pwm tso tus neeg sawv cev tuaj yeem siv yog tias tsim nyog.

③ Shutdown processing Lub sijhawm kaw ntawm PBT yog nyob rau hauv 30min, thiab qhov kub thiab txias tuaj yeem txo qis rau 200 ℃ thaum kaw.Thaum ua dua tom qab kaw lub sijhawm ntev, cov khoom siv hauv lub thoob yuav tsum tau muab pov tseg thiab tom qab ntawd cov khoom siv tshiab yuav tsum tau ntxiv rau kev tsim khoom ib txwm muaj.

④ Tom qab ua tiav cov khoom Feem ntau, tsis tas yuav muaj kev kho mob, thiab yog tias tsim nyog, 1 ~ 2h kev kho mob ntawm 120 ℃.

PBT tshwj xeeb ntsia hlau

Rau PBT, uas yooj yim rau decompose, rhiab heev rau lub siab thiab xav tau ntxiv iav fiber ntau, PBT tshwj xeeb ntsia hlau ua kom ruaj khov siab thiab siv ob lub alloy los txhim kho hnav tsis kam rau cov khoom siv iav fiber ntau (PBT + GF).