1. Kev npaj cov khoom nyoos
Thaum pib ntawm cov kab ntau lawm, PP resin pellets yog pub rau hauv lub hopper. Cov khoom siv raw yog feem ntau ntawm homopolymer lossis copolymer PP resin, nrog rau cov dej ntws ntws (MFR) feem ntau tswj ntawm 0.2 thiab 0.5 g / 10 min los xyuas kom meej cov txheej txheem zoo.
2. Extrusion thiab Plasticization - Kev hloov ntawm lub cev lub cev
Tom qab nkag mus rau hauv extruder, cov khoom siv raw tau hloov pauv los ntawm "lub xeev ruaj khov mus rau lub xeev molten" uas tau tsav los ntawm cov ntsia hlau:
Khoom-xeev thauj khoom: Cov khoom yog compacted thiab xa mus rau pem hauv ntej nyob rau hauv seem pub.
Melting thiab Plasticization: Los ntawm cov cua kub sab nraud (feem ntau 160-240 degree) thiab kev sib txhuam ntawm cov ntsia hlau thiab lub thoob, cov khoom maj mam yaj.
Homogenization thiab Pressure Build-up: Cov khoom molten yog ntxiv homogenized nyob rau hauv homogenization cheeb tsam, thiab txaus siab yog tsim los mus rau thaum kawg tsim ib tug nruam, kub-uniform melt flow.
3. Tuag Forming-Los ntawm "Formless" mus rau "Pib"
Lub plastified yaj yog yuam mus rau hauv extrusion tuag, uas yog ib qho tseem ceeb rau kev txiav txim siab cov yeeb nkab cov duab.
Tsim: Tuag tsim ua raws li cov dej dynamics thiab cov ntsiab lus thermodynamics ntawm "melt flow balance" los xyuas kom meej cov extrusion ntawm cov khoom PP.
Flow: Lub yaj nkag mus rau hauv ib lub cylindrical inlet thiab maj mam hloov raws cov ntws channel mus rau hauv ib qho annular sib txawv uas phim cov yeeb nkab cross-section.
Sizing: Raws li cov yaj tawm ntawm qhov sib txawv ntawm qhov tuag, nws tsim ib qho hollow parison nrog cov duab ua ntej, npaj nws rau tom qab shaping.
4. Sizing thiab txias - Lub tsev "Cov pob txha muaj zog"
Cov yeeb nkab parison tshwm sim los ntawm qhov tuag yog kub heev thiab nquag deformation, yuav tsum tau shaping tam sim ntawd thiab solidification los ntawm sizing thiab txias khoom.
Lub tshuab nqus tsev nqus tsev vacuum: Lub tshuab nqus tsev twj tsim lub siab tsis zoo ntawm 20.0-53.3 kPa hauv lub tes tsho loj. Atmospheric siab ces nias rau sab phab ntsa ntawm cov yeeb nkab kub dawb paug tiv thaiv lub puab phab ntsa ntawm lub tes tsho kom ua tiav shaping.
Forced Cooling: Kev khiav dej txias (feem ntau 15-25 degree) tshem tawm cov cua sov los ntawm kev txau los yog immersion, ua rau cov khoom PP kom khov sai thiab ruaj khov nws qhov ntev.
5. Rub thiab txiav -Rau qhov "Cov khoom tiav"
Cov yeeb nkab kho yuav tsum tau rub tawm ntawm cov kab ntau lawm thiab txiav kom loj raws li qhov xav tau.
Pulling: Ib qho kev khiav- hom rub lub tshuab tuav cov yeeb nkab thiab rub tawm ntawm cov kab ntau lawm ntawm qhov ceev tsis tu ncua. Qhov ceev yuav tsum phim qhov ceev extrusion; ruaj khov rub yog qhov tseem ceeb los xyuas kom meej qhov ntev ntev thiab phab ntsa thickness ntawm cov yeeb nkab.
Txiav: Ib qho encoder ntsuas cov yeeb nkab ntev hauv lub sijhawm. Thaum tus nqi preset tau mus txog, lub kaw lus tswj activates lub txiav mechanism. Kev tsim khoom niaj hnub no feem ntau siv cov nti- txiav dawb, uas ua rau lub ntsej muag du uas yuav tsum tsis muaj kev ua haujlwm thib ob.