Ol buk bilong skul long 'plasticizing' i save tingim plastik insait long strongpela hap bilong skru olsem wanpela strongpela bet we i no gat muvmen namel long ol plastik 'granules'. Bihain ol i save painimaut spit bilong karim samting i go het long rot bilong kalkuletim gutpela sindaun bilong muv na friksen namel long dispela strongpela bet na wol bilong baret, ples bilong givim kaikai long skru, na ples bilong skru senel.
Dispela rot i narakain tru long trupela rot na ol i no inap yusim long skelim kaikai bilong ol plastik granul i gat kain kain seip. Sapos ol plastik 'granules' i liklik, ol bai bruk na pundaun taim ol i pulim i go het long wol bilong barel, na isi isi ol bai kamap strong na kamapim ol strongpela 'plug'. Taim diamita bilong ol 'granules' i klostu wankain olsem 'screw channel depth', 'trajectory' bilong ol i olsem wanpela 'linear motion' long 'screw channel' long 'radial', na tu wanpela 'linear motion' wantaim liklik angle. Bikos plastik i stap isi long 'screw channel' taim ol 'granules' i bikpela, 'conveying speed' i isi. Taim ol 'granules' i kamap bikpela inap long 'diameter' bilong ol i winim 'screw channel depth' taim ol i go insait long 'compression section', plastik bai pas namel long 'screw' na 'barrel'. Sapos strong bilong pulim i go het i no inap long winim strong bilong mekim ol plastik 'granules' i kamap stret, plastik bai pas long 'screw channel' na i no inap long muv i go het.
Taim plastik i kamap klostu long mak bilong en long melt, plastik we i pas wantaim baret i stat long melt, na kamapim wanpela 'molten film'. Taim tiknes bilong dispela 'molten film' i winim spes namel long skru na baret, het bilong ol 'screw ribs' i save skrapim 'molten film' long insait wol bilong baret i go long as bilong ol 'screw ribs', na isi isi i save bungim i go insait long wanpela 'vortex-like flow zone-molten pul- i go antap long pes bilong ol 'screw ribs'.
Bikos long 'screw channel depth' bilong 'molten section' i wok long go daun isi isi na 'molten pool' i go daun, strongpela bet i go insait long wol bilong baret, na dispela i mekim hat i go hariap long hot barel i go long strongpela bet. Long wankain taim, rotesen bilong skru i save kamapim 'shearing action' long 'molten film' namel long strongpela bet na insait wol bilong baret, na dispela i save meltim strongpela samting long hap namel long 'molten film' na strongpela bet. Taim strongpela bet i spiral i go het, volium bilong en i go daun isi isi, na volium bilong molten pul i go antap isi isi. Sapos mak bilong go daun bilong 'solid bed thickness' i liklik long 'rate' bilong go daun bilong 'screw channel depth', 'solid bed' inap long pasim liklik o olgeta 'screw channel', na dispela inap long kamapim senis long 'plastisaisesen', o inap long kamapim 'localized overheating' bikos long bikpela presa na 'frictional heat' i go antap.
Long hap bilong 'homogenization' bilong skru, strongpela bet i bruk bikos em i liklik, na i kamapim ol liklik strongpela hap we i stap nabaut insait long 'molten pool'. Ol dispela strongpela hap i save melt long rot bilong 'friction' na 'heat transfer' wantaim melt i stap klostu. Long dispela taim, bikpela wok bilong skru em long kirapim plastik melt long mekim miks i kamap wankain. Melt velositi distribusen i stat long bikpela spit klostu long wol bilong baret i go long liklik spit klostu long daunbilo bilong skru senel. Sapos 'screw channel' i no dip tumas na 'melt viscosity' i antap, orait 'friction' namel long ol 'melt molecules' bai i strong tru.
Bikos long bikpela senis long 'melting rate', 'melt viscosity', 'melting temperature range', 'viscosity sensitivity' long 'temperature' na 'shear rate', 'corrosiveness' bilong ol 'high-tempereture decomposition gases', na 'coefficient of friction' namel long ol plastik patikel, ol nomol jeneral-pepos skru i save kisim bikpela 'shear section' taim ol i wok long stretim ol plastik ol pasin (olsem PC, PA, hai-molekula-weit ABS, PP-R, PVC, na ol narapela). Dispela samting inap long pinis sapos ol i daunim spit bilong skru, tasol dispela i save bagarapim wok bilong prodaksen. Long mekim gutpela wok bilong mekim ol dispela plastik i kamap plastik, kampani bilong mipela i kamapim ol spesel skru na baret bilong mekim ol dispela plastik i kamap plastik. Ol dispela spesel skru na barel i kamap bilong stretim ol bikpela hevi olsem 'solid friction coefficient', 'melt viscosity', na 'melting speed' bilong ol plastik we mipela i stori long en.
