Scribd
Upload
689 views11 pages

Seminar 1 Rheometer

This document discusses rubber rheometers and rheographs. It explains that rheometers measure the rheological properties of rubber as it is heated from uncured to fully vulcanized. A rheograph plots shear stress over time at constant temperature and strain. The document then discusses oscillating disk rheometers and the typical torque curve generated. It explains the significance of values on the curve like minimum torque, maximum torque, scorch times, and cure times. Finally, it lists some practical applications of rheometers in quality control and process optimization in the rubber industry.

Uploaded by

Swapnil Ahire
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PPT, PDF, TXT or read online on Scribd
689 views11 pages

Seminar 1 Rheometer

This document discusses rubber rheometers and rheographs. It explains that rheometers measure the rheological properties of rubber as it is heated from uncured to fully vulcanized. A rheograph plots shear stress over time at constant temperature and strain. The document then discusses oscillating disk rheometers and the typical torque curve generated. It explains the significance of values on the curve like minimum torque, maximum torque, scorch times, and cure times. Finally, it lists some practical applications of rheometers in quality control and process optimization in the rubber industry.

Uploaded by

Swapnil Ahire
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PPT, PDF, TXT or read online on Scribd
You are on page 1/ 11

RUBBER RHEOMETER &

RHEOGRAPH

:
Presented By
SWAPNIL S. AHIRE
Roll No : 10MS60R02
INTRODUCTION
 RHEOLOGY:Mechanism of flow behavior
 Rubber/elastomer is viscoelastic material:- Its
rheological properties are govern by viscosity
& elasticity
 RHEOMETER: Is the instrument which predict
total rheological behavior of rubber
compound when it is heated from uncured
form to total vulcanized form
 RHEOGRAPH:Shear stress Vs Time at constant
shear strain & constant temperature
Rheological properties are function of :-

Applied stress

Degree of strain

Time

Temperature and chemical composition of stock


TYPES OF RHEOMETER

For ODR :
Oscillating frequency:- 100 cycles/min
Arc of oscillation :- ± 3º
Air pressure :- 60 psi(4.2kg/cm2)
Rotor used in ODR
What is a rubber compound ?
Ingredients PHR Role

Natural rubber 100 Base polymer

GPF Black 60 Reinforcing filler

Aromatic oil 10 Plasticizer

Zinc oxide 5 Activator

Stearic acid 2 Co-Activator

TMQ 1.5 Anti-oxidant

Wax 1.5 Anti-ozonant

CBS 1.5 Accelerator (delayed


action)
TMTD 0.2 Accelerator(ultra fast)

Sulphur 1.8 Vulcanizing agent


Marching

Phase I Phase 2 Phase 3 physical


Processing Curing properties
Rheometric Torque(lb/in)

Plateau

Reversion

MI MH

ML

ts2 ts5 tc50 tc90 RT

Time(min)

TYPICAL RHEOMETER CURVE


Significance of typical rheometric curve values:-
Torque values:-

1. MI(initial torque).
2. ML(minimum torque) :- It is a measure of the stiffness and viscosity
of unvulcanized compound.
3. MH(maximum torque) :- Highest value recorded in plateau or
reverting curve.

Time values:-

1. ts2(induction time). It is scorch time for viscosity to rise two units


above ML.
2. ts5(scorch time) :- It is time for viscosity to rise five units above ML.
3. tc50 :- time at which 50% curing has taken place.
4. tc90(optimum cure time) :- Time at which 90% curing has taken
place.
Significance of typical rheometric curve
values:-

Derived values:-
1. Cure rate :- CR=100/(tc90-ts2). It is the rate at which cross linking
and development of stiffness of compound occurs after scorch point
i.e compound changes from soft plastic to tough elastic material.

2. Thermo plasticity:- TP=(MI-ML)

3. Reversion time:- RT it is time to reach 98% MH after passing MH


Practical applications of Rheometer:-

 Tocheck quality of raw materials


 To check quality of mixing
 To check rheological behavior of given compound
 To set processing parameters
 To study different curing systems with respect to time and
temperature.
 To predict properties of final product

Rheometer test is essential quality control


parameter in rubber industry.

You might also like