Understanding Dynamic Properties of Rubber and Rubber Products

Course Number: AP5221
Date: 06/03/2013 - 06/04/2013
Time: 8:00 AM - 4:00 PM
Location: Akron Polymer Training Center, Akron, OH 44325-5404
Cost: $900 USD
CEU's: 1.5
Instructor: John Dick and Karl Winkler

Course Overview

This two-day course gives a thorough review of dynamic properties from A to Z. It defines rubber dynamic properties in practical terms. Special attention is given to performance applications of rubber components and parts. Also, a review of different properties of rubber itself and how these different properties are affected by formulation changes are also discussed. This course includes an effective balance between the practical and theoretical aspects of rubber dynamic properties.

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

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