• Recognize dynamic properties of rubber and rubber products
• Identify performance applications of rubber components and parts
• Compare how different properties are affected by formulation changes

Course Outline

Day 1: Part 1 – Basic Principles of Rheology and Dynamic Properties of Rubber

ELASTIC QUALITY
– Hooke’s Law
– Modulus
– Exercises

VISCOUS QUALITY
– Flow
– Viscosity
– Calculation of Viscosity
– Newtonian Fluids
– Non-Newtonian Behavior
– Exercises

VISCOELASTIC QUALITY
– Voigt and Maxwell Models
– Illustrations
– Creep Experiments
– Stress Relaxation Experiments

SINUSOIDAL DEFORMATION AND RESPONSES
– S’, S”, S*, Phase Angle, Tan
– Rebound
– Uncured tan
– Cure tan
– Exercise

INSTRUMENT CONFIGURATIONS AND MEASURE UNITS
– Ranges of test conditions
– Types of tests
– Frequency Sweep
– Strain Sweep
– Temperature Sweep
– Cure Test
– Time Sweep
– Test configurations for polymer characterization
– Test configurations for Processability
– Test configurations for cure and after-cure dynamic property measurements
– Die cavity vs unsealed cavity
– Calculation of % strain for angle of oscillation
– Laminar movement
– Estimating Pressure
– Exercise

SHEAR MODULUS
– G’, G”, G*
– Calculations and Use of Conversion Factors
– Vector Analysis
– Use of G’ vs S’ in High Strain Sweep
– Exercise

DYNAMIC VISCOSITY
– eta’, eta”, eta *
– Calculation from G’, G” and G*
– Calculation of Shear Rates
– Cox-Merz Rule
– Exercise

COMPLIANCE
– J’, J”, J*
– Calculation from G’, G”, and G*
– Relevance
– Exercise

EXTENSION/COMPRESSION MODULUS
– E’, E”, E*
– Relation of E to G
– Poisson’s Ratio
– MTS vs RPA Testing
– D’, D”, D*
– Calculation of D from E
– Exercise

SPRING RATE CONSTANTS AND DAMPING COEFFICIENTS
– Spring Rate Definition
– K’, K”, K*
– Vector Analysis
– Damping Coefficients

TIME AND TEMPERATURE DEPENDENT PROPERTIES
– Definition of WLF
– Examples of WLF with Polymers and Mixed Stocks

TEST ANALYSIS
– Test Sensitivity – S/N Ratio
– Minimum Detectable Level (MDL)
– Correlation Studies

Day 1: Part II Applications – Testing and Evaluating Dynamic Properties in Rubber Materials and Rubber Products

WHICH DYNAMIC TEST METHOD TO USE
– Free Vibration – Yerzley, Rebound, Bayshore, Lupke
– Forced Vibration – DMS, DMTA, RSA, RPA

SYSTEM APPLICATION TESTS
– Frequency
– Natural frequency
– Damped Natural Frequency
– Forced Vibration
– Free Vibration
– Mode of Vibration
– Single Degree of Freedom System
– Multiple Degree of Freedom System
– Resonance
– Harmonic

AUTOMOTIVE NVH TERMS
– Lateral, Fore & Aft
– Longitudinal
– Pitch
– Yaw
– Roll
– Buzz
– Boom
– Roar
– Crowds
– Harshness
– Plushness
– Shake
– Shuffle, Bobble
– Road Noise, Buzz

Day 2

AUTOMOTIVE APPLICATIONS
– Transverse Engine Six Degrees of Freedom
– Vertical Bounce Mode Effect on Vehicle
– Single Degree of Freedom System
– Natural Frequency of Resonant Frequency
– Inertance Transfer Function
– Evaluating Rubber Damping – Log Decrement Technique
– Two Degrees of Freedom Systems

VIBRATION DAMPER DESIGN PROCEDURE
– Tuned Vibration Absorbers
– Shear Modulus vs. Durometer Hardness
– Mass Ratio
– Tuning Ratio
– Damping Level

FORCED VIBRATION TESTING OF RUBBER MATERIALS AND PRODUCTS
– Examples
– Mold Bonded Compression
– Quad Lap Shear (QLS)
– Dynamic Stiffness
– MTS Shape Factor
– Strain Sweeps
– Compressive Static Graphs
– Effects of Surface Conditions, Bonding, Sandpaper, Dry/Clean, Talc, Vasoline
– Frequency Sweep
– Material Transmissibility
– Pre-strain Sweep
– Temperature Sweep
– Heat Build Up

MECHANICAL FATIGUE TESTING OF RUBBER
– Fatigue Life and Crack Growth
– Primary Failure
– Secondary Failure
– Fatigue Test Control Methods
– Stress Control (Load Control)
– Strain Control (Displacement Control)
– Indirect Control
– Calculated Variables
– Spectrum
– Remote Parameter Control (RPC)
– Engine Mount Fatigue Graphs
– Crack Initiation and Growth, Micro Cracking, Strain Energy and Crack Propagation

Day 2: Part III – Compounding Rubber for Dynamic Properties

ELASTOMERS
– Important Elastomer Properties (Tg, MW, MWD, LCB)
– Plastic vs. Rubber
– Kinetic Theory of Rubber Elasticity
– Molecular Motions in Different Regions of the Master Curve
– Time Temperature Superpositioning (WLF Equation)
– Effects of Chemical Structure on Glass Transition (Tg)
– Main Chain Flexibility, Steric Hindrance, Symmetry, Branching, MW
– Effects of Blending
– Natural Rubber (NR)
– Polyisoprene (IR)
– Polybutadiene (BR)
– Styrene Butadiene Rubber (SBR)
– EPDM
– Polychloroprene (CR)
– Butyl Rubber (IIR)
– Nitrile Rubber (NBR)
– Silicone Rubber (Q)

PLASTICIZERS
– Predictive Equation for Tg
– Compatibility

VULCANIZATION
– Optimal Cure
– Effects of Crosslink Type

CARBON BLACK
– Carbon Black Reinforcement
– Effects of Surface Area
– Effects of Structure
– Effects of Surface Activity

COMPOUND MIXING
– Effects of Mixing on Strain Amplitude Dependence of G’ and Tan delta
– Dispersion vs. Fill Factor