Extruder Principles and Operation

Front Cover
Springer Science & Business Media, 1995 M10 31 - 494 pages
This book is intended to fill a gap between the theoretical studies and the practical experience of the processor in the extrusion of thermoplastic polymers. The former have provided a basis for numerical design of extruders and their components, but generally give scant attention to the practical performance, especially to the conflict between production rate and product quality. In practice extruders are frequently purchased to perform a range of duties; even so, the operator may have to use a machine designed for another purpose and not necessarily suitable for the polymer, process or product in hand. The operator's experience enables him to make good product in unpromising circumstances, but a large number of variables and interactions often give apparently contradictory results. The hope is that this book will provide a logical background, based on both theory and experience, which will help the industrial processor to obtain the best performance from his equipment, to recognize its limitations, and to face new problems with confidence. Mathematics is used only to the extent that it clarifies effects which cannot easily be expressed in words; ifit is passed over, at least a qualitative understanding should remain. The approximate theory will not satisfy the purist, but this seems to the authors less important than a clear representation of the physical mechanisms on which so much of the polymer processing industry depends. M. J. STEVENS J. A.
 

What people are saying - Write a review

User Review - Flag as inappropriate

one of my favorite ! I very liked the explanation about the energy lost in shear and extensional flow as well as the good description of the single screw behavior.

Contents

Introduction
1
12 METHOD
2
Practical extrusion processes and their requirements
4
21 SHAPING PROCESSES AND THEIR REQUIREMENTS
6
22 OTHER APPLICATIONS AND THEIR REQUIREMENTS
17
Flow behaviour relevant to extrusion
25
32 SHEAR FLOW
31
33 EXTENSIONAL FLOW
45
92 EFFECTS OF CONTROLLED VARIABLES
280
93 POLYMER PROPERTIES
286
94 SCREW DESIGN
289
95 OPERATIONAL STRATEGIES
293
Twinscrew extruders
310
101 NONINTERMESHING SCREWS
312
102 PARTIAL INTERMESHING
314
COUNTERROTATION
317

34 ELASTIC EFFECTS
46
35 MEASUREMENT OF VISCOSITY AND ELASTICITY
49
Thermal and energy properties in processing
52
42 THERMAL CONDUCTION
54
43 NONISOTHERMAL FLOW AND HEAT TRANSFER
57
44 MIXING
60
Extrusion dies
63
52 FACTORS INFLUENCING THE PERFORMANCE OF AN EXTRUSION DIE
65
53 EXTRUSION DIES FOR SOME PROFILES
75
54 GENERAL PRINCIPLES OF DIE DESIGN
89
55 SPECIFIC ASPECTS OF DIE DESIGN
101
56 OPERATIONAL STRATEGIES FOR PROBLEMSOLVING
117
Principles of melt flow in singlescrew extruders
125
62 DERIVATION OF FLOW EQUATION
127
63 LEAKAGE FLOW
138
64 OUTPUT EQUATIONS AND LONGITUDINAL PRESSURE PROFILES FOR COMMON SCREW TYPES
140
65 GRAPHICAL REPRESENTATION OF OUTPUT FOR SCREWDIE COMBINATIONS INCLUDING VENTING
149
66 OUTPUT CORRECTIONS
162
67 PSEUDOPLASTIC FLOW
165
68 NONISOTHERMAL FLOW
171
Solids conveying and melting in singlescrew extruders
173
72 PHENOMENOLOGICAL DESCRIPTION OF SOLIDS CONVEYING AND MELTING
177
73 THEORETICAL ANALYSIS
187
Principles of energy balance
223
NEWTONIAN ISOTHERMAL CASE
227
83 PSEUDOPLASTIC ISOTHERMAL APPROXIMATION
233
84 POWER IN NONISOTHERMAL FLOW
234
85 EFFECT OF VARIABLES ON ENERGY BALANCE
249
Operation of singlescrew extruders
268
COROTATION
324
105 COMPARISON OF MACHINE TYPES
342
Extruder operation as part of a total process
346
112 STABILITY
353
113 SHEAR HISTORY
358
114 CONTROL
360
115 SCALEUP
370
Practical extruder operation
378
122 COLOUR AND GRADE CHANGING
381
123 STARTUP AND SHUTDOWN
383
124 DISMANTLING AND CLEANING
386
125 WASTE RECOVERY
391
Application to the individual machine
393
Properties of polymers for heat and flow
399
Derivations of flow and pressure
407
B2 ESTIMATION OF LEAKAGE FLOWS
409
B3 LONGITUDINAL PRESSURE PROFILES
412
B4 PRESSURE GRADIENTS IN A STEPPED SCREW
414
B5 FURTHER EXAMPLES OF QP DIAGRAMS
417
Energy consumption and energy balance
421
C2 DERIVATION OF POWER ABSORBED IN SCREW
429
C3 HEAT FLOWS IN MELT PUMPING SECTION
432
C4 DISTRIBUTION OF SHEAR HEATING AND TRANSVERSE CIRCULATION
444
C5 TEMPERATURE VARIATION IN THE FLIGHT CLEARANCE
452
Stability of melt pumping section
461
List of tables
463
References
465
Index
471
Copyright

Other editions - View all

Common terms and phrases

Bibliographic information