Kev tshawb fawb thiab kev siv PBT engineering plastics hloov kho

PBT yog ib hom crystalline linear saturated polyester ua los ntawm terephthalic acid (PTA) lossis dimethyl terephthalate (DMT) thiab 1,4-butanediol (BDO) los ntawm polycondensation reaction, nrog cov khoom siv kho tshuab zoo, nws cov qauv molecular symmetric tuaj yeem ua tiav ze stacking, nrog crystallinity siab, tuaj yeem crystallized sai sai ntawm qhov kub qis. Nrog cov khoom siv kho tshuab zoo, nws cov qauv molecular symmetrical kom ua tiav ze stacking, nrog crystallinity siab, tuaj yeem crystallized sai sai ntawm qhov kub qis. PBT qhov chaw ua tiav yog yooj yim rau ntws molding thiab molding lub sijhawm luv luv, tuaj yeem txo cov nqi tsim khoom, thiab PBT muaj cov dej noo-resistant, abrasion-resistant, roj-resistant thiab lwm yam zoo, creep kuj me me.

Vim tias PBT muaj cov khoom siv crystalline thiab cov khoom tsis yog crystalline, nws yooj yim hloov kho nws los ntawm kev ntxiv lwm yam khoom. Txawm li cas los xij, PBT kuj yooj yim hlawv, thiab cov khoom siv refrigerant sib cuag nrog cov khoom me me, cov khoom dielectric tsis txaus ntawm cov khoom nyias-phab ntsa uas yooj yim rau warping thiab lwm yam tsis zoo, txwv nws qhov kev siv. Txhawm rau them rau qhov tsis muaj kev ua tau zoo ntawm PBT resin ntshiab, PBT resin tau tshawb fawb txog kev hloov kho.

1. PBT engineering plastics extrusion tshuab Tam sim no qhov xwm txheej ntawm kev hloov kho kev tshawb fawb

Nyob rau xyoo tas los no, cov tuam txhab lag luam tsim ntau yam kev siv thev naus laus zis tshiab thiab cov khoom tshiab, PBT engineering plastics kom muaj kev ua haujlwm siab, ua haujlwm tau zoo, thiab muaj ntau yam kev coj ua. Rau cov kev xav tau ntawm kev lag luam, kev hloov kho kom txhim kho kev ua haujlwm ntawm PBT, uas tau txais kev nyiam los ntawm kev ua lag luam. Tam sim no, kev hloov kho copolymerization, kev hloov kho cov khoom siv inorganic filling, nanocomposite technology, kev hloov kho sib xyaw thiab lwm txoj hauv kev feem ntau yog siv hauv tsev thiab txawv teb chaws los txhim kho kev ua tau zoo ntawm PBT. Kev tshawb fawb txog kev hloov kho cov ntaub ntawv PBT feem ntau tsom mus rau lub zog siab, hluav taws kub tsis kam, tsis tshua muaj warpage, tsis tshua muaj nag lossis daus, tsis tshua muaj dielectric thiab lwm yam.

txhua yam khoom

Lub zog tensile ntawm PBT resin ntshiab, lub zog flexural thiab flexural modulus qis, hauv kev lag luam tsis tuaj yeem siv dav, yuav tsum tau hloov kho kom txhim kho cov khoom siv kho tshuab. Cov iav fiber muaj qhov zoo ntawm kev siv tau zoo, cov txheej txheem yooj yim thiab tus nqi qis, thiab lwm yam. Kev ntxiv cov iav fiber rau PBT ua rau cov txiaj ntsig qub ntawm PBT resin tuaj yeem coj los ua si, thiab lub zog tensile, flexural thiab notched impact strength ntawm PBT cov khoom tau zoo dua.

Ntxiv rau cov iav fiber, lwm cov fibers tuaj yeem raug qhia los txhim kho cov khoom siv kho tshuab ntawm PBT. Zeng Deming et al. siv cov basalt luv luv los txhim kho PBT resin, tom qab lub luag haujlwm ntawm tus neeg sawv cev txuas ntawm basalt tuaj yeem sib xws zoo dua nrog PBT, zoo txhim kho cov khoom siv kho tshuab ntawm PBT composites.

Nplaim retardant zog

Lub tshuab PBTpelletizing ntshiab tsuas yog ncav cuag HB theem, yooj yim hlawv thiab hlawv tas mus li, nplaim taws yooj yim kis, nws daim ntawv thov hauv tsheb, khoom siv hluav taws xob thiab ntaub thiab lwm yam yog txwv. Cov tshuaj halogenated nplaim taws thiab cov tshuaj halogenated nplaim taws feem ntau ntxiv rau PBT rau kev hloov kho nplaim taws. Cov tshuaj halogenated nplaim taws tso tawm cov pa lom uas muaj hydrogen halide thaum hlawv, uas ua rau tib neeg noj qab haus huv thiab ib puag ncig ecological, thiab qee cov tshuaj halogenated nplaim taws tau raug txwv hauv European Union. Kev hloov kho nplaim taws ntawm PBT feem ntau siv cov tshuaj phosphorus nplaim taws thiab cov tshuaj inorganic nplaim taws.

Thaum siv cov khoom siv hluav taws xob uas tsis muaj zog, ntxiv cov ntsiab lus ntau dhau yuav ua rau cov khoom siv kho tshuab poob qis; tab sis cov khoom siv hluav taws xob phosphorus tsis muaj qhov tsis zoo no, thiab muaj cov pa luam yeeb tsawg, tsis muaj tshuaj lom, thiab muaj zog hluav taws xob ntau. Cov khoom siv hluav taws xob phosphorus feem ntau yog sib xyaw nrog cov tshuaj nitrogen kom ua tiav cov txheej txheem hluav taws xob zoo dua. Cov khoom siv hluav taws xob phosphorus hauv cov txheej txheem combustion tsim cov phosphoric anhydride los ua kom cov roj hlawv tau, cov txheej carbon tuaj yeem txo cov cua sov, ncua lossis tiv thaiv kev tsim cov pa roj hlawv, thiab phosphoric anhydride tom qab cua sov los tsim cov khoom siv molten uas npog qhov chaw ntawm cov khoom siv hluav taws xob, cuam tshuam kev tso tawm cov pa roj hlawv.

Kev hloov pauv ntawm cov khoom siv

Cov khoom siv PBT molecular slip yog yooj yim rau kev taw qhia, crystallization, ua rau cov khoom shrinkage loj, ua rau PBT qhov chaw, tshwj xeeb tshaj yog cov khoom loj nyias-phab ntsa ntawm warping deformation. Rau cov iav fiber reinforced PBT, vim yog ntxiv cov iav fibers nrog anisotropy, ua rau cov khoom shrinkage tus nqi sib txawv hauv kev txhaj tshuaj molding, ua rau cov khoom warping deformation ntawm cov khoom, tsis tsuas yog cuam tshuam rau qhov zoo ntawm cov khoom yas thiab kev ua haujlwm ntawm kev teeb tsa, tab sis kuj cuam tshuam rau lub zog ntawm cov yas.

Rau qhov kev hloov pauv ntawm PBT qhov chaw, ntxiv rau kev txhim kho cov duab ntawm cov khoom, kev tsim pwm thiab cov txheej txheem molding, kuj tseem tuaj yeem hloov kho kom qeeb qhov kev hloov pauv ntawm PBT cov ntaub ntawv. Nyob rau hauv xyoo tas los no, qhov kev hloov pauv ntawm PBT cov ntaub ntawv feem ntau yog txhim kho los ntawm kev sau inorganic thiab kev sib xyaw kub. Kev sau inorganic suav nrog ib qho kev sau inorganic thiab kev sib xyaw ua ke nrog iav fiber, thiab cov ntaub ntawv inorganic siv rau kev sau feem ntau suav nrog talc, mica, wollastonite, iav hlaws dai, kaolin, calcium sulfate whiskers thiab lwm yam.

Kev ua tau zoo ntawm nag los

Vim tias cov khoom siv raw ntawm PBT cov khoom siv tsis tuaj yeem ua haujlwm tag nrho thaum lub sijhawm tsim khoom, cov khoom me me, oligomers, thiab lwm yam raug tsim tawm, thiab cov khoom ua los ntawm cov khoom siv PBT tsis tau hloov pauv tsim cov nag lossis daus nyob rau hauv qee qhov xwm txheej, uas cuam tshuam rau qhov ua tau zoo ntawm cov khoom. Thaum cov khoom siv PBT siv rau hauv lub tshuab ntsiag to hauv lub tub yees compressor, lub cev muaj zog coil pob txha thiab lub tshuab cua txias rwb thaiv tsev pob txha, thiab lwm yam, vim muaj cov xwm txheej ua haujlwm tshwj xeeb, cov nag lossis daus ntawm ntau cov khoom me me hauv cov tub yees (Freon, dichlorodifluorodichloromethane) yaj hauv lub raj tub yees yooj yim thaiv lub raj tub yees, yog li nws lub tub yees tsis ua haujlwm.

PBT feem ntau yog ua rau cov molecule me me zwitterion ntawm cov resin nws tus kheej thiab me ntsis ntawm cov additives uas muaj nyob hauv. Kev siv cov iav fiber thiab cov resin viscosity siab, uas muaj qee qhov adsorbent tuaj yeem txo qhov ntau ntawm PBT nag lossis daus. Tam sim no, cov khoom siv inorganic porous tseem ceeb adsorption tsim thiab ntxiv cov neeg sawv cev thaiv, saw extender, 1,4 cyclohexanedimethanol (CHDM) thiab lwm yam tshuaj rau kev hloov pauv nag lossis daus PBT.

Dielectric zog

Cov ntaub ntawv PBT hauv kev sib xyaw ua ke thiab kev tiv thaiv hluav taws xob thiab lwm yam kev siv, cov khoom dielectric ntawm qhov ceev ntawm kev xa xov tooj cua, kev poob teeb liab thiab lwm yam ua lub luag haujlwm tseem ceeb. Nyob rau xyoo tas los no, cov khoom dielectric ntawm cov ntaub ntawv insulating tau muab tso rau pem hauv ntej ntau qhov kev cai nruj dua, qhov yuav tsum tau ua ntawm dielectric tas mus li ntawm cov ntaub ntawv insulating resin tsis pub tshaj 2.8. Thaum cov khoom dielectric ntawm cov ntaub ntawv PBT ntshiab tsis tuaj yeem ua tau raws li qhov yuav tsum tau ua ntawm kev sib txuas lus, kev tsim cov khoom dielectric tsawg, kev poob dielectric qis ntawm cov ntaub ntawv PBT yog qhov tseem ceeb heev.

Tam sim no, cov khoom dielectric ntawm PBT feem ntau yog hloov kho los ntawm kev sau thiab sib xyaw cov copolymers dielectric qis, thiab cov khoom siv fillers feem ntau yog polytetrafluoroethylene hmoov thiab cov hlaws iav khoob. Cov pa roj carbon nanotubes kuj muaj qee qhov zoo rau cov khoom dielectric ntawm PBT cov ntaub ntawv, tab sis ntxiv cov ntsiab lus siab dhau ntawm cov khoom siv dielectric tas li thiab dielectric poob nce.

Nrog rau kev loj hlob sai ntawm cov tsheb fais fab, nws cov kev sib kis hluav taws xob siab ntawm cov khoom siv sib txuas dielectric zog xav tau siab dua, txawm hais tias PBT arc tsis kam zoo, yooj yim kom paub txog kev kub ceev molding tab sis lub zog dielectric qis, tsis tuaj yeem paub txog hauv cov tsheb fais fab rau kev sib kis hluav taws xob siab. Los ntawm chav kawm conductor lossis ceramic filler ntawm PBT dielectric cov khoom ntawm kev hloov kho kom txhim kho lub zog dielectric ntawm cov khoom kom ntseeg tau tias muaj kev nyab xeeb ntawm cov tsheb fais fab.