Screw extrusion‐flow patterns and recent theoretical developments

Abstract

Flow patterns, screw geometry, non-isothermal conditions and non-Newtonian behavior are all considered for that part of the screw which contains molten polymer.

Fundamentals of Global Modeling for Polymer Extrusion

“…These basic studies analyzed one-dimensional flow through a rectangular channel of infinite width. Later, these models were improved by considering the transverse flow caused by the screw flights (Carley and Strub [145], Squires [146]), the effect of channel curvature (Booy [147], Squires [148]), and the effect of flight clearance (Mallouk and Mc Kelvey [149], Maddock [150]).…”

Melt Conveying in Single-Screw Extruders: Modeling and Simulation

“…To account for the effect of channel curvature, approaches were introduced for deep channels that are based either on cylindrical polar or helical coordinates. One of the first theoretical approaches that avoided the flat-plate model was presented by Squires [ 20 ], who derived a correction factor for the drag flow in the traditional Newtonian pumping model (Equation (46)), which is valid for the limiting case of zero helix angle and infinite aspect ratio. Booy [ 155 ] extended the theory by including the effect of helix angle and its variations with the radius; his model consisted of a screw channel bounded by the cylindrical barrel and screw root surfaces, as well as by the two sides of a helical flight.…”

“…Over the past century, the technical progress of extruders in polymer processing has gone hand in hand with extensive theoretical and experimental research summarized in numerous books [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] and reviews [ 19 , 20 , 21 , 22 , 23 , 24 ]. Recently, Wilczyńnski et al [ 25 ] provided a comprehensive literature survey of the modeling and simulation of single- and twin-screw extruders, placing special emphasis on global modeling aspects.…”

Nghiên Cứu Dòng Chảy Của Nhựa Nóng Chảy Trong Thiết Bị Đùn Trục Vít Đơn

“…Do đó, các lý thuyết về dòng chảy lưu chất trong máy đùn trục vít được mở rộng để xử lý lưu chất phi Newton. Từ đầu thập niên 60, đã có công trình nghiên cứu của P. H. Squires [11] giả thiết dòng lưu chất trong máy đùn trục vít là phi Newton và bất đẳng nhiệt. Vì lưu chất được đùn ra là phi Newton, độ nhớt sẽ thay đổi ở các vị trí khác nhau trong máy đùn do sự biến thiên của tốc độ cắt.…”