Lub hauv paus rau kev txiav txim siab precision txhaj tshuaj molding yog qhov tseeb ntawm kev txhaj tshuaj molded cov khoom, uas yog, qhov ntev kam rau ua, cov duab kam rau ua thiab nto roughness ntawm cov khoom. Yuav tsum muaj ntau yam xwm txheej rau kev txhaj tshuaj molding, tab sis qhov tseem ceeb tshaj plaws yog plaub yam tseem ceeb ntawm cov khoom siv yas, kev txhaj tshuaj pwm, txheej txheem txhaj tshuaj molding thiab cov cuab yeej txhaj tshuaj molding.
Thaum tsim cov khoom yas, cov ntaub ntawv yas engineering yuav tsum raug xaiv ua ntej, thiab cov yas yas uas muaj peev xwm ntawm kev txhaj tshuaj molding yuav tsum xaiv cov ntaub ntawv uas muaj cov khoom siv siab, qhov ntev ruaj khov, zoo creep tsis kam, thiab ib puag ncig kev ntxhov siab tawg. Qhov thib ob, lub tshuab txhaj tshuaj molding tsim nyog yuav tsum raug xaiv raws li cov khoom siv yas xaiv, qhov tseeb ntawm qhov khoom tiav, qhov hnyav ntawm daim, qhov xav tau zoo thiab cov qauv pwm xav tau. Nyob rau hauv tus txheej txheem ntawm kev ua, cov yam tseem ceeb cuam tshuam rau precision txhaj molding khoom mas yog los ntawm precision ntawm cov pwm, shrinkage ntawm txhaj molding, thiab ntau yam kev hloov nyob rau hauv lub ambient kub thiab av noo ntawm cov khoom.
Hauv kev txhaj tshuaj molding precision, cov pwm yog ib qho ntawm cov yuam sij kom tau txais cov khoom yas precision uas ua tau raws li qhov yuav tsum tau ua. Cov pwm siv rau kev txhaj tshuaj molding yuav tsum ua tau raws li qhov yuav tsum tau ua ntawm cov khoom loj, precision thiab cov duab. Tab sis txawm tias qhov tseeb thiab qhov loj ntawm cov pwm zoo ib yam, qhov loj ntawm cov khoom yas molded yuav tsis sib haum vim qhov sib txawv ntawm qhov shrinkage. Yog li ntawd, nws yog ib qho tseem ceeb heev kom tswj tau qhov shrinkage tus nqi ntawm cov khoom yas hauv precision txhaj molding tshuab.
Txawm hais tias tus qauv tsim pwm tsim nyog lossis tsis tuaj yeem cuam tshuam ncaj qha rau tus nqi shrinkage ntawm cov khoom yas, vim tias qhov loj ntawm cov pwm kab noj hniav yog tau los ntawm kev ntxiv qhov kwv yees shrinkage tus nqi rau qhov luaj li cas ntawm cov khoom yas, thiab tus nqi shrinkage yog pom zoo los ntawm cov yas. chaw tsim tshuaj paus los yog engineering plastics phau ntawv Nws tsis yog tsuas yog hais txog lub rooj vag daim ntawv, rooj vag txoj hauj lwm thiab tis ntawm cov pwm, tab sis kuj muaj feem xyuam rau cov siv lead ua orientation (anisotropy) ntawm engineering plastics, cov duab, qhov loj, qhov deb ntawm lub rooj vag thiab cov duab thiab qhov loj ntawm cov khoom yas. Qhov chaw ntsig txog.
Lub ntsiab yam tseem ceeb cuam tshuam rau shrinkage ntawm plastics yog tshav kub shrinkage, theem hloov shrinkage, orientation shrinkage, compression shrinkage thiab elastic rov qab, thiab lwm yam, thiab cov influencing yam tseem ceeb muaj feem xyuam rau molding tej yam kev mob los yog kev khiav hauj lwm tej yam kev mob ntawm precision txhaj molded khoom. Yog li, kev sib raug zoo ntawm cov kev cuam tshuam no thiab kev txhaj tshuaj molding thiab nws cov tsos mob yuav tsum tau txiav txim siab thaum tsim pwm, xws li kev txhaj tshuaj siab thiab kab noj hniav thiab ntim ceev, txhaj tshuaj kub thiab pwm kub, pwm qauv thiab rooj vag daim ntawv thiab kev faib tawm, thiab kev cuam tshuam ntawm cov khoom xws li lub rooj vag cross-sectional cheeb tsam, cov khoom phab ntsa thickness, cov ntsiab lus ntawm reinforcing muab tub lim nyob rau hauv cov ntaub ntawv yas, crystallinity thiab orientation ntawm cov khoom yas. Kev cuam tshuam ntawm cov khoom saum toj no kuj sib txawv nrog cov ntaub ntawv yas sib txawv, lwm yam molding tej yam kev mob xws li kub, av noo, txuas ntxiv crystallization, kev ntxhov siab sab hauv tom qab molding, thiab kev hloov hauv kev txhaj tshuaj molding tshuab.
Txij li cov txheej txheem txhaj tshuaj molding yog txheej txheem ntawm kev hloov cov yas los ntawm cov khoom (hmoov lossis pellets) rau cov kua (melt) rau khoom (khoom). Los ntawm cov pellets mus rau yaj, thiab tom qab ntawd los ntawm cov yaj mus rau cov khoom, muaj qhov kub thiab txias, thaj chaw kev ntxhov siab, qhov chaw ntws, thiab qhov chaw ntom ntom hauv nruab nrab. Raws li kev sib koom ua ke ntawm cov teb no, cov yas sib txawv (thermosetting lossis thermoplastic, crystalline) Los yog non-crystalline, reinforced lossis non-reinforced, thiab lwm yam) muaj cov qauv polymer sib txawv thiab cov khoom siv rheological. Txhua yam uas cuam tshuam rau saum toj no "thaj chaw" yuav muaj kev cuam tshuam rau lub cev thiab cov khoom siv kho tshuab, qhov loj me, cov duab, precision thiab zoo li zoo ntawm cov khoom yas.
Nyob rau hauv txoj kev no, kev sib raug zoo ntawm cov txheej txheem txheej txheem thiab kev ua haujlwm ntawm cov khoom siv polymer, cov qauv tsim thiab cov khoom yas yuav raug qhia los ntawm cov khoom yas. Kev txheeb xyuas cov kev sib txuas sab hauv no yog qhov tseem ceeb heev rau kev tsim cov txheej txheem kev txhaj tshuaj molding tshuab, rationally tsim thiab tsim pwm raws li kev kos duab, thiab txawm tias rationally xaiv txhaj tshuaj molding ua khoom siv. Precision txhaj tshuaj molding kuj txawv ntawm kev txhaj tshuaj molding zoo tib yam nyob rau hauv cov nqe lus ntawm kev txhaj tshuaj siab thiab kev txhaj tshuaj. Precision txhaj molding feem ntau siv high-pressure los yog ultra-high-pressure txhaj thiab high-speed txhaj kom tau ib tug me me molding shrinkage.
Raws li cov laj thawj saum toj no, ntxiv rau kev xav txog cov qauv tsim ntawm cov pwm dav dav thaum tsim cov pwm txhaj tshuaj precision, cov ntsiab lus hauv qab no kuj yuav tsum tau txiav txim siab:
① Txais qhov tsim nyog pwm loj kam rau ua;
② Tiv thaiv molding shrinkage yuam kev;
③ Tiv thaiv kev txhaj tshuaj deformation;
④ Tiv thaiv kom tsis txhob deformation;
⑤ Txo qhov kev tsim pwm ua yuam kev;
⑥ Tiv thaiv qhov yuam kev ntawm pwm precision;
⑦ Tswj pwm precision.
