| 摘要 |
FIELD: process engineering.SUBSTANCE: invention relates to extrusion of plastics, particularly, to production of polycarbonate. Extrusion is performed in two-screw or multiple-shaft extruder using screw elements with paired unilateral rotation and paired scraping screw shafts. Note here that screw profiles, both active and passive, feature the pattern "compaction section - transition section - channel section - transition section". Note that compaction section feature the pattern "ledge are - side area -ledge area" while channel section feature the pattern "clearance section - side section - clearance section". Transition section represents as sequence of screw profile areas starting with side area and ending also in side area. Note that screw element compaction section is described by side area location relative to screw profile rotational axis at angle ?_fb1 larger than half the opening angle between housing angles (?_fb1 ?arccos(0.5*a/ra)) or equal thereto. Ledge area is located relative to screw profile rotational axis at angle ?_kb1 smaller than or equal to angle difference of screw one-way Erdmenger profile on subtracting opening angle between housing angles (?_kb1??-4*arccos(0.5*a/ra)). Another ledge area is located relative to screw profile rotational axis at angle ?_kb2 smaller than or equal to angle difference of screw one-way Erdmenger profile on subtracting opening angle between housing angles (?_kb2??-4*arccos(0.5*a/ra)). Note that screw element compaction section is described by side area location relative to screw profile rotational axis at angle ?_fb1 larger than half the opening angle between housing angles (?_fb1 ?arccos(0.5*a/ra)) or equal thereto. Clearance area is located relative to screw profile rotational axis at angle ?_nb1 smaller than or equal to angle difference of screw one-way Erdmenger profile on subtracting opening angle between housing angles (?_nb1??-4*arccos(0.5*a/ra)). Another clearance area is located relative to screw profile rotational axis at angle ?_nb2 smaller than or equal to angle difference of screw one-way Erdmenger profile on subtracting opening angle between housing angles (?_nb2??-4*arccos(0.5*a/ra)).EFFECT: higher extrusion pressure, reduced power consumption.16 cl, 76 dwg, 17 tbl, 19 ex |
