COMPRESSION MOLDING 391
• Crack resistance
• Thermal stability
• Density, etc.
These must be somehow related to fundamental polymer properties such as:
• Composition
• Branching
• Cross-linking
• Stereo-regularity etc.
Unfortunately process variables affect properties and the relationship between the pro¬cess variables and end-use properties is generally very difficult and not well established. In situ real-time monitoring of compression molding IS of crucial importance to polymer scientists and engineers engaged in efforts to optimize processes and products. Moreover, many process variables that affect product quality namely non-ideal mixing and conveying, and strong process non-linearity related to limited cycles and multiple steady states.
Two big expenses for any processing are:
• Failure to quickly and accurately troubleshoot process upsets and equipment problems
• Failure to realize the operating potential of its process through optimization
• Minor upsets and equipment problems which are not identified and resolved quickly can progress into much larger problems potentially resulting in:
๐ lost production
๐ off-spec product
o equipment loss
o catastrophic accidents.
Additionally, operating a process at suboptimal performance results in elevated operat¬ing costs due to:
• Increased energy costs
• Equipment reliability costs
• Lower yields
• Longer startups, etc.
Therefore, the ability to troubleshoot and optimize process operations are two of the most valuable skills operation personnel can possess.
Troubleshooting requires a comprehensive analysis of:
• The process
• Mold design
• Material
Compression molding tends to focus on process modifications to solve problems. There may be longer cycle times, secondary rework operations or formulation modifications that