ABSTRACT
I. Introduction .................................................................................................. 334 A. Raw Materials Handling ....................................................................... 334 B. Mixing ................................................................................................... 335 C. Forming ................................................................................................. 336 D. Vulcanization ........................................................................................ 336
II. Physical and Chemical Peptizers .................................................................. 338 A. Mastication ............................................................................................ 338 B. Processing with Peptizing Agents ......................................................... 341 C. Inuence of Peptizing Agents on Vulcanizate Properties .................... 342
III. Lubricants .....................................................................................................344 A. General Discussion................................................................................344 B. Properties and Mode of Action of Lubricants .......................................346 C. Processing with Lubricants ...................................................................348 D. Inuence of Lubricants on Vulcanizate Properties ............................... 350
IV. Homogenizing Agents .................................................................................. 351 A. Examples and Function ......................................................................... 351 B. Processing with Homogenizing Agents ................................................ 354
V. Dispersing Agents ......................................................................................... 355 A. Properties of Dispersing Agents ........................................................... 355 B. Processing with Dispersing Agents....................................................... 355
VI. Tackiers ...................................................................................................... 355 A. Denition and Manufacturing Importance ........................................... 355 B. Theories of Autohesion and Tack.......................................................... 356 C. Processing with Tackiers .................................................................... 359
VII. Plasticizers .................................................................................................... 359 A. Functions of Plasticizers ....................................................................... 359 B. Plasticizer Theory .................................................................................360 C. Compatibility ........................................................................................ 361 D. Selection of Plasticizers ........................................................................ 361 E. Processing of Plasticizers ...................................................................... 363
In conjunction with the chemicals used in a rubber formulation to ensure acceptable product characteristics, a number of ingredients may be incorporated to allow or improve processing with the manufacturing equipment available in the plant. The stages of rubber processing may be broken down into raw materials handling, mixing, forming, and vulcanization. Some of the factors that may inuence the process economics and product acceptability in these stages are listed in Table 8.1. The function of the processing additives is to minimize or overcome any problems associated with product fabrication while maintaining, or even improving, product performance. Before going into detail, some examples of acceptable performance criteria for processing additives at the four stages in product manufacture are presented briey.
