Kev xaiv cov txheej txheem kub kub ua kom haum rau cov khoom siv yas yog qhov tseem ceeb rau kev ua kom cov khoom zoo thiab kev ua haujlwm zoo, nrog rau qhov kub thiab txias, viscosity, thermal stability, thiab abrasiveness raws li qhov tseem ceeb. Rau qhov dav - cov hom phiaj yas (PP, PE, ABS, PS), qhib- hom kub khiav yog qhov zoo vim lawv cov nqi qis, kev saib xyuas yooj yim, thiab sib haum nrog qhov kub thiab txias (180-250 degree). Cov yas no muaj cov dej ntws zoo, tsis muaj viscosity, thiab tsawg kawg thermal degradation txaus ntshai, ua rau qhib - hom nozzles txaus rau tsis yog - qhov tseem ceeb xws li cov khoom siv hauv tsev thiab ntim khoom. Multi-kab kab noj hniav qhib tshuab yog qhov zoo tagnrho rau siab- ntim ntawm lub raj mis thiab cov thawv ntim khoom pov tseg.
Rau engineering plastics (PA66, PBT, POM, PC), uas yuav tsum tau kub dua melting kub (250-320 degree) thiab muaj viscosity ntau dua, valve-gated kub runners yog nyiam. Cov yas no yooj yim rau stringing thiab txias weld kab, thiab valve -gated nozzles kom huv si kaw lub rooj vag thiab meej yaj tswj. High- kub resistant kub khiav nrog npib tsib xee-chromium cua kub ntsiab lus thiab insulating Cheebtsam yog tsim nyog los tswj qhov kub thiab txias thiab tiv thaiv degradation. Rau cov khoom siv hluav taws xob puv (PA+30%GF, PPS+40%GF), uas yog abrasive heev, kub khiav nrog hardened steel nozzles thiab hnav- cov coatings resistant yog qhov tseem ceeb rau kev ua haujlwm ntev.
Rau siab - cov yas ua tau zoo (PEI, PEEK, PPSU) xav tau 320℃+ yaj kub, tshwj xeeb siab - kub khiav nrog ceramic rwb thaiv tsev thiab platinum-rhodium thermocouples yog yuav tsum tau. Cov yas no muaj qhov tsis zoo thermal stability, yuav tsum tau tswj qhov kub thiab txias (± 0.5 degree) kom tsis txhob degradation. Kev kho mob- qib plastics (PP, PE, PVC rau kev siv kho mob) yuav tsum tau siv lub tshuab kub kub kom huv si nrog du, corrosion- cov chaw tiv taus thiab tsis muaj qhov chaw tuag los tiv thaiv cov kab mob loj hlob, nrog valve-gated nozzles kom muaj kev sib kis{11}}dawb qhov chaw.
