Extrusion molding txheej txheem ntawm PPH yeeb nkab. Kev xaiv cov khoom siv raw: resin rau extruded polypropylene kav, thiab nws melt flow rate yog nyob rau hauv thaj tsam ntawm {{0}}.2 mus rau 0.3 g/10min. Feem ntau, cov resins nrog cov yaj ntws ntawm qhov ntau ntawm 0.2 txog 0.4 g / 10min yog siv ntau dua. Cov txheej txheem ntau lawm kab ntawm polypropylene yeeb nkab: tib yam li cov txheej txheem ntau lawm ib ntus ntawm lub hom phiaj dav dav polyethylene yeeb nkab, cov txheej txheem ua raws li hauv qab no. Qhib lub hnab los xyuas qhov zoo ntawm cov ntaub ntawv raw → extruder plasticizes thiab melts raw cov ntaub ntawv → pwm tsim raj dawb paug → nqus sizing lub tes tsho txias thiab sizing → nqus tshuaj tsuag txias → yeeb nkab txias thiab txias → traction → txiav → zoo soj ntsuam → cia. Kev xaiv cov khoom siv: Cov kav dej polypropylene feem ntau yog tsim los ntawm cov hom phiaj ib leeg-ntsia hlau extruders. Cov qauv ntsia hlau yog qhov sib npaug ntawm qhov sib npaug thiab qhov sib npaug qhov tob gradient hom, qhov sib piv yog (25-30): 1, thiab compression piv yog 2.5-4. Cov qauv ntawm txoj kev tuag yog feem ntau ncaj-los ntawm hom, thiab qhov ntev ntawm qhov ncaj ntawm mandrel yog L=(2-5)D (D yog txoj kab uas hla ntawm cov yeeb nkab, tus nqi loj dua yog noj thaum txoj kab uas hla me me, thiab tus nqi me me yog noj thaum txoj kab uas hla ntawm cov yeeb nkab loj). Sab hauv txoj kab uas hla ntawm lub tes tsho loj yog d=D / (1-δ) (D yog txoj kab uas hla ntawm cov yeeb nkab, δ yog qhov shrinkage tus nqi ntawm cov yeeb nkab, feem ntau δ=2. 7 feem pua -4.7 feem pua ).
