ABSTRACT
I. Extrusion .......................................................................................................................... 79
A. Monolayer Extrusion ................................................................................................ 79
B. Coextrusion .............................................................................................................. 81
II. Calendering ...................................................................................................................... 83
III. Coating and Laminating ................................................................................................... 83
A. Coating Processes ..................................................................................................... 83
B. Laminating Processes ............................................................................................... 84
IV. Metallization ..................................................................................................................... 85
V. Orientation ........................................................................................................................ 88
A. Orientation Process .................................................................................................. 89
B. Shrink Films ............................................................................................................. 90
C. Stretch Films ............................................................................................................ 91
VI. Cross-Linking ................................................................................................................... 91
VII. Microperforation .............................................................................................................. 92
VIII. Injection Molding ............................................................................................................. 93
IX. Blow Molding .................................................................................................................. 93
A. Extrusion Blow Molding .......................................................................................... 94
B. Injection Blow Molding ........................................................................................... 95
C. Stretch Blow Molding .............................................................................................. 95
X. Thermoforming ................................................................................................................ 97
XI. Foamed (Cellular) Plastics ............................................................................................... 98
XII. Heat Sealing ..................................................................................................................... 98
A. Conductance Sealing ................................................................................................ 98
B. Impulse Sealing ........................................................................................................ 99
C. Induction Sealing ................................................................................................... 100
D. Ultrasonic Sealing .................................................................................................. 100
E. Dielectric Sealing ................................................................................................... 100
F. Hot-Wire Sealing ................................................................................................... 101
G. Testing of Heat Seals ............................................................................................. 101
References ................................................................................................................................... 101
Extrusion is one of the most important plastics processing methods currently in use. Most plastic
materials are processed in extruders, and commonly pass through two or more extruders on their
way from the chemical reactor to the finished product. All thermoplastics are formed into sheet or
film (commonly ,100 mm) by the process of screw extrusion. The first screw extruder designed
specifically for thermoplastic materials appears to have been made by Paul Troesterin in Germany
in 1935.
