| 摘要 |
<p>A centripetal extrusion unit where the relatively smooth stationary face features a spiral rib with just enough clearance from the opposing face to avoid seizure. Pref. the clearance between the faces is adjustable in the range 50-100 mu. Pref. an ancillary face rotates at a rather high rate near the focus of the main rotary plate to smooth the discharge rate into an axial exit passage. Pref. the stationary plate has peripheral annular groove with venturi bulges to obtain force feeding from the adjacent base of a feed hopper. The compression ratio along the spiral flow path is pref. 2:1. The surface roughnesses of the various zones in the unit are critical. The plasticisation unit is for use in conjunction with ancillary machinery for profile or coating extrusion, injection or intrusion moulding, or blow moulding of thermoplastics. Can generate output pressures ca 200 bars, with good homogenisation and degassing characteristics. Injection moulding or pulse extrusion machines may include a separate pressure intensification chamber with an independent injection ram.</p> |
