Cast Polyurethane Elastomer Processing and Troubleshooting Guide

Click here to access the Baytec Cast Elastomer Processing and Troubleshooting guide in the RESOURCES section of this Web Site. The table of contents below outlines the information contained in the guide.

Table of Contents

• Calculations
• Mold Design
• Material Handling Procedures
  • Prepolymer Storage and Handling
  • Curative/Chain Extender Handling
  • Health & Safety Information
  • Regulatory Compliance
• Process Overview
• Mold Preparation
  • Mold Cleaning
  • Release Agents and Their Application
  • Mold Conditioning
  • Adhesive Application for Metal Bonding
  • Substrate Preparation
  • Adhesive Application
• Molding Techniques
  • Conventional Open Cast Molding
  • Centrifugal Molding
  • Closed Mold/Injection Molding
• Preparation for Processing
  • Ratio Control
  • Flow Calibration
  • Temperature and Pressure Effects
• Prepolymer Degassing
  • Batch Degassing
  • Continuous or On-the-Fly Degassing
• Casting Operations
  • Metering and Mixing
  • Mold Preheating and Mold Release
  • Mold Filling
  • Mixhead Flashing
  • Initial Cure and Demold
  • Postcure
  • Maturation
• Finishing and Machining
  • Straight-Turning with High-Speed Tool Steel
  • Parting-Off
  • Milling
  • Drilling
  • Grinding
  • Cutting
• Quality Control
  • Statistical Process Control
  • Process Analysis
  • Standard Operating Procedures
• Troubleshooting
  • Material Handling
  • Ratio Control
  • Reactivity Control
  • Mixing and Incompatibility
  • Air and Porosity
  • Preparation Problems
    • High-Viscosity Prepolymer (Still Processable)
    • High-Viscosity Prepolymer (Unprocessable)
    • Gelled material in Container
    • Skin on Surface of Prepolymer
    • Solids in Prepolymer
    • Dark Prepolymer Color
    • Prepolymer foams too much
  • Processing Problems
    • Bubbles in the Mix Stream or Foaming in the Mold
    • Fast Reactivity
    • Slow Reactivity
    • Excessive Vapors
  • Post-Processing Problems
    • Excessive Shrinkage
    • Soft Parts
    • Hardening Parts
    • Clear Parts
    • Voids in Parts from Air Entrapment
    • Cracking, Fissures, Striations, Severe Shrinkage in Parts
    • Ferning/Snowflake Effect on Surface
    • Blistering, Skinning on Surface
    • Wet Spots on Part or Areas of Uncured Material
    • Poor Tear Resistance and Cheesy Appearance at Demold
    • Poor Adhesion
    • Inconsistent Color
    • Poor Green Strength
• Development and Technical Support
• Appendix
• Chain Extender Tables