Glass fibres plant
Additives for Polymers · 1988
Fully intermeshing, corotating twin-screw extruders (TSEs) are frequently used in many operations that involve polymer blending, devolatilization, or the incorporation of solids such as fillers or reinforcing agents into a polymeric matrix. This is largely due to their flexible screw design, which can be fitted ‘to the job,’ good mixing capacity and self-wiping action. Besides, the advantage of TSEs over conventional single-screw extruders is their high solids intake rate and melting capacity.The contribution will cover three aspects of twin-screw extrusion: (i) the axial pressure profile caused by the presence of subsequent zones which are partially filled, combined with locally pressurized zones, (ii) the mechanisms involved in the so-called dissipative mix-melting process, and (iii) the importance of screw geometry and typical sequence of screw elements required for optimal mixing.