Page 611 - Carrahers_Polymer_Chemistry,_Eighth_Edition

574 Carraher’s Polymer Chemistry

• Movement of the resin to the shaping apparatus through application of heat and/or pressure
and other flow aiding processes, and

• Removal and recycling of unwanted solvent, unreacted monomer(s), byproducts, and waste (fl ash)

The shaping step may include any single or combination of the following:
• Die forming (including sheet and film formation, tube and pipe formation, fi ber formation,

coating, and extrusion)
• Molding and casting

• Secondary shaping (such as film and blow molding, thermoforming), and
• Surface treatments (coating and calendering)

Postshaping processes include welding, bonding, fastening, decorating, cutting, milling, drilling,
dying, and gluing.
Polymer processing operations can be divided into five broad categories:

• Spinning (generally for fi bers)
• Calendering
• Coating
• Molding, and
• Injection
Table 18.1 lists some of the major shapes produced by each of these processing groups.

TABLE 18.1
Major Forms of Polymer Processing Groupings

Process Typical Form of Product
Calendering Films, sheets
Coating Film
Injection Solid
Reaction injected
Reciprocating screw
Two-stage
Molding
Blow Hollow
Displacement
Extrusion
Injection/transfer
Stretch
Cold Solid
Compression Solid, hollow
Rotational Solid, hollow
Thermoforming Hollow
Transfer Solid
Spinning Fibers
Dry
Gel
Melt
Reaction
Wet

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