It is a zone which screw takes polymer from the hopper. Main purpose of this section is taking polymer from the hopper and conveys it into the screw channel. Mainly this section has stable pitch depth. Polymers are pushed forward by this pitch. Solid conveying directly depends on material slipping on the screw and holding the barrel with the friction forces.
Simple Extruder Screw
Solid transport “Feeding Zone”
** Melting or transition zone
Main purpose of this section is to melt the feeding plastic. Along the section polymer granules melt and are formed melting pool. Polymers compress with decreasing depth in conventional screw design and it provides to melt the polymer. Then compressed material, have a high pressure, is pushed forward to pumping section.
** Dosing Zone (Metering or pumping zone)
It is the most important section on the screw. Pumping section builds up enough pressure for exiting the material from the die.
Volumetric quantity of feeding section over pumping section is known as Compression Ratio of the screw.
In conventional 3-stage-screw, pressure reaches the maximum value at the end of the screw but it is sensitive to the counter pressure coming from the mold and output capacity can decreases. In grooved feeding system, pressure reaches a maximum value in front of the groove channels.Best extrusion conditions are obtained by maximum molten and homogenous material pushing through the mould under stable pressure conditions.
Volumetric quantity of feeding section over pumping section is known as Compression Ratio of the screw.
In conventional 3-stage-screw, pressure reaches the maximum value at the end of the screw but it is sensitive to the counter pressure coming from the mold and output capacity can decreases. In grooved feeding system, pressure reaches a maximum value in front of the groove channels.Best extrusion conditions are obtained by maximum molten and homogenous material pushing through the mould under stable pressure conditions.
Contact
Contact
E-Mail
WhatsApp
Facebook
Linkedin
TOP