Lub plhaub ntawm lub plhaub kev txhaj tshuaj (lub nrawm sab nraub qaum thiab sab hauv sab hauv) yog vim qhov tsis zoo ntawm cov khoom tsis txaus ua kom tiav thaum lub qhov txias dua. Peb feem ntau ntsib cov xwm txheej uas muaj kev ntxhov siab ntxiv, cov dej nkag tau ntxiv, lub sijhawm txhaj tshuaj ntxiv, thiab qhov teeb meem ntsws tsis tuaj yeem daws tsis tau. Ntawm qhov feem ntau siv cov ntaub ntawv raw, vim yog qhov ceev txias npaum li cas, lub shrinkage ntawm PC khoom yog qhov nyuaj tshaj los daws kom tau, thiab lub shrinkage thiab shrinkage ntawm cov ntaub ntawv PP kuj tsis yooj yim. Yog li, thaum muaj teeb meem loj ntawm shrinkage ntawm tuab qhov chaw, nws yog ib qhov tsim nyog yuav tau txais qee cov kev txhaj tshuaj tiv thaiv kev tsis sib haum, txwv tsis pub nws yuav nyuaj rau daws qhov teeb meem. Nyob rau hauv kev xyaum ntau lawm, peb tshawb txog cov txheej txheem pab tau zoo kom ua tiav qhov teeb meem ntawm kev txhaj tshuaj molding.
Ua ntej tshaj plaws, nyob rau hauv lub hauv paus ntawm kom ntseeg tau tias cov yas txhaj molded tsis yog deformed, txais txoj kev los ntawm qhov ua kom lub sij hawm txias, thiaj li hais tias cov yas txhaj molded cov tshuaj yuav tuaj yeem tso tawm ntawm kev kub. Ntawm lub sijhawm no, qhov ntsuas kub ntawm txheej txheej ntawm cov yas txhaj tshuaj yog tseem siab, thiab daim tawv nqaij tsis dhau zog, yog li qhov txawv ntawm qhov kub ntawm qhov txawv me me, uas yog siv rau tag nrho kev txo, ua li txo qhov txo qis hauv lub plhaub molded txhaj tshuaj. Txij li cov txheej txheem ntim txheej txheem ntawm qhov kev txhaj tshuaj tiv thaiv pwm no tas li, qhov ntau qhov ua kom luv, ua kom tsawg zog, thiab sab hauv lub qhov ntswg thiab qhov chaw sab nrauv shrinkage degree yog li txo. Qhov teeb meem ntawm kev txav thiab cov yeeb nkab yog tshwm sim los ntawm qhov kub ntawm qhov pwm thiab lub peev xwm txias. Cov tsos ntawm cov yas molded yas tsuas solidified yog tseem mos (tsis zoo li qhov nyuaj ntawm lub PC tom qab cov pwm raug tso tawm, nws yog qhov yooj yim kom shrink lub qhov), thiab nws tsis tag tshem tawm. Txij thaum lub tshuab nqus cov kaus hniav ua rau lub tshuab nqus tsev, qhov zoo li ntawm cov quav tshuaj tiv thaiv cov txheej txheem yog nruj nruj hauv qab hauv siab ntawm atmospheric siab, thiab nrog cov quab yuam, qhov teeb meem ntsws tshwm sim. Ntxiv mus, qeeb qeeb ntawm qhov chaw zom zaws ceev, qhov feem ntau nws yuav tsum ntsws, xws li cov ntaub ntawv PP, thiab qhov feem ntau nws yuav tsum thawb lub qhov.
Yog li, tom qab lub hnab yas txhaj molded yog prematurely tso tawm, lawv yuav tsum tau zoo kom txias, thiaj li hais tias cov yas molded yam koom rau ib yam hardness, yog li ntawd lawv yog cov tsawg dua yuav shrink. Txawm li cas los xij, yog tias qhov teeb meem ntawm kev txav yog loj dua, tsis muaj cua txias yuav tsis raug tshem tawm. Nws yog ib qho tsim nyog yuav tau txais txoj kev los ntawm cov dej khov dej kom ua rau cov khoom ntim ntawm cov yas nrawm nrawm nrawm kom tsis txhob txav, tab sis sab hauv lub qhov ntswg tseem yuav muaj nyob. Rau cov khoom siv ntom ntom xws li PP, vim cov nyom thiab nqus cov qog, vim cov yas txhaj molded yuav muaj ib cov duab ntxoo los yog cov yeeb yaj kiab, tab sis cov qib ntawm shrinkage tau raug txo kom tsawg.