Los ntawm qhov kev xav ntawm peb yam uas txiav txim siab cov khoom ntawm PTFE cov khoom - qhov hnyav molecular, crystallinity thiab voidage, qhov voidage feem ntau cuam tshuam los ntawm lub siab ua ntej, thiab qhov hnyav molecular thiab crystallinity tag nrho cov kev hloov pauv nrog qhov sib txawv sintering.Yog li ntawd,txheej txheem sinteringCov xwm txheej ua lub luag haujlwm txiav txim siab hauv cov khoom kawg ntawm cov khoom xws li ntom, hardness, permeability thiab txhua yam khoom.
Los ntawm qhov kev xav ntawm peb yam uas txiav txim siab cov khoom ntawm PTFE cov khoom - qhov hnyav molecular, crystallinity thiab voidage, qhov voidage feem ntau cuam tshuam los ntawm lub siab ua ntej, thiab qhov hnyav molecular thiab crystallinity tag nrho cov kev hloov pauv nrog qhov sib txawv sintering.Yog li ntawd, cov txheej txheem sintering ua lub luag haujlwm txiav txim siab hauv cov khoom kawg ntawm cov khoom xws li ntom, hardness, permeability thiab txhua yam khoom.
Wang ping pom tias covCov txheej txheem sintering ntawm PTFEtau cuam tshuam los ntawm qhov nce thiab poob ceev, sintering kub thiab sintering lub sij hawm.Qhov loj ntawm cov khoom, qhov qeeb qeeb ntawm kev nce thiab txias, lub sij hawm sintering ntev dua.Lub sintering kub ntawm ncua kev kawm ntawv resin yog siab dua li ntawm dispersion resin.Lub sintering kub ntawm cov khoom siv ntshiab yog siab dua li cov khoom ntim khoom.Nyob rau hauv dav dav, tus nqi ntawm kev ua kom sov yog sai dua tus nqi ntawm cov cua txias.Hauv tib lub sintering rauv, cov khoom siv ntshiab thiab cov khoom ntim tsis tuaj yeem sib xyaw;Cov khoom siv sib txawv sintering tsis tuaj yeem sib xyaw.Cov khoom ntawm cov khoom sib txawv tsis tuaj yeem sib xyaw.Noj cov khoom ntawm 3-txheej molded voj voog phaj nrog txoj kab uas hla ntawm 1 m, thickness ntawm 20 hli, ob txheej li ntshiab ptfe thiab nruab nrab txheej raws li sau ptfe ua piv txwv, lub compression zog, dabtsi yog khoov zog, hardness thiab lwm yam mechanical zog ntawm lub ncig laminated phaj ua los ntawm cov cuab yeej no tau zoo heev.
Liu xianlan kawm txog cov txheej txheem txheej txheem, kev tsim qauv thiab pwm tsim cov yam ntxwv ntawm PTFE, txheeb xyuas qhov tsis xws luag thiab ua rau PTFE cov khoom tsim los ntawm txias nias thiab sintering, thiab muab tso rau pem hauv ntej txoj kev kho mob.PTFE tuaj yeem molded los ntawm ntau yam txheej txheem preforming, xws li molding, extrusion, hydraulic molding, thawb molding thiab lwm yam kev ua, thiab ces sintered mus rau qhov kawg khoom.PTFE molding feem ntau yog ua los ntawm suspended resin.Thaum lub thickness ntawm daim ntawv tsawg dua 1.5 hli, disperse resin yog siv.Nws cov txheej txheem thev naus laus zis: resin - sieve (sab laug resin tom qab pounding, xoob, thiab 20 mesh mesh sieve) - xovxwm (PTFE hmoov loading pwm nyob rau hauv siab ntawm 20 mus rau 35 MPa, tom qab xovxwm compaction forming) - sintering (hauv 370 ~ 380 "C kub sintering nyob rau hauv sintering rauv) - molded khoom (nyob rau hauv lub xeev dawb nyob rau hauv lub pwm los yog tom qab txias kom tiav tus tsim raws li yuav tsum tau los ntawm lub rooj tsavxwm, rods, hlab, gaskets thiab packing khoom, thiab lwm yam). Txoj kev sib npaug lossis roj hmab molding hauv nws cov txheej txheem kev khiav hauj lwm yog: muab lub hnab roj hmab tso rau hauv qhov tuag - txuas nrog lub twj tso kua mis dej, sau cov dej swell lub hnab roj hmab rau hauv lub cylindrical - resin sib npaug ntawm lub hnab thiab sab nraud pwm kaw - txuas ntxiv mus maj mam nce. dej siab, dej puv mus txog 12 ~ 13 mpa siab tswj 30 min: tom qab dej - decompression, ripping, sintering, txias yog siv cov ci thiab huv si tsos.Push tseem hu ua paste extrusion molding, 20 ~ 30 mesh sieve dispersion resin thiab organic kua (xws li toluene, petroleum ether, cov roj hnyav) sib tov 1: 5 paste sib tov, preloading rau hauv tuab phab ntsa cylinder billet, thawb rau hauv lub tog raj kheej compressor. , cua sov, nrog lub plunger laub molding, tom qab ziab hauv 360 ~ 380 ° C kub sintering, tom qab txias cov khoom muaj zog thawb lub raj, pas nrig, thiab lwm yam.Extrusion molding yuav muab faib ua ob hom: ntsia hlau extrusion thiab plunger extrusion.Lub pre-sintered resin tom qab crushing thiab sifted yog ntxiv rau cov khoom cylinder.Los ntawm kev sib hloov ntawm cov ntsia hlau los yog reciprocating thawb ntawm plunger, cov khoom siv raw yog thauj mus rau lub extruder tib lub sij hawm ntawm compaction.
Wang ping tau kawm txog cov txheej txheem tsim ntawm PTFE ua npuas ncauj khoom.Suspended polytetrafluoroethylene yog siv los ua raw khoom, thiab condensed cyclic aromatic hydrocarbons raug xaiv los ua tus neeg sawv cev pore.Tom qab sib tov, preforming khoom yog preformed thiab sintered.Nyob rau hauv thawj theem ntawm sintering, ziab txheej txheem yog saws los ua kom pore-forming tus neeg khiav dim, thiab ces resintering theem yog nkag mus.Cov ntaub ntawv ua npuas ncauj nrog cov dielectric sib txawv tuaj yeem npaj tau sib txawv kom tau raws li ntau yam kev xav tau.
Chen Xu et al.ua compression test thiab sintering test ntawm PTFE, tham txog kev sib raug zoo ntawm qhov ceev, compression zog thiab compression modulus, thiab soj ntsuam lub compression zog ntawm cov qauv nyob rau hauv txawv sintering txheej txheem, thiab tau ntau tsim nyog molding siab thiab sintering txheej txheem.Cov txiaj ntsig tau pom tias lub zog compression ntawm PTFE txo qis nrog qhov nce ntawm kev nias siab, thiab cov compression modulus tau nce nrog qhov nce ntawm kev nias.Lub molding siab yog 27.5mpa, sintering kub yog 380 C, thiab lub sij hawm rwb thaiv tsev yog 4h.
Txhawm rau kov yeej qhov tsis zoo ntawm cov ntshiab ptfe, xws li kev puas tsuaj tsis zoo thiab cov thermal expansion coefficient loj, Raytheon tau kawm txog bronze-filled particles hauv ptfe, thiab nthuav dav daim ntawv thov ntawm ptfe.Cov pa sov nias molding ntawm ptfe yog tus cwj pwm los ntawm lub voj voog ntev, kev ua haujlwm tsis zoo, qhov tsis zoo ntawm qhov raug thiab du, thaum lub sij hawm sov molding molding hauv txoj kev tshawb no muaj tsawg dua cov txheej txheem ua haujlwm, lub voj voog luv luv thiab txhim kho cov cuab yeej zoo.
Post lub sij hawm: Mar-14-2017