Definition of Rheology o Rheology TXVTC [Greek rheos -"to flow"]is the study of deformation and flow of matter ● Name was coined by Dr. Marcus Reiner instead of the more obscure “continuum mechanics” Motto of the Society of Rheology:“Panta Rhei”or “everything flows” after Heraclitus :l
Definition of Rheology • Rheology [Greek rheos - “to flow”] is the study of deformation and flow of matter • Name was coined by Dr. Marcus Reiner instead of the more obscure “continuum mechanics” • Motto of the Society of Rheology:“Panta Rhei” or “everything flows” - after Heraclitus
THE VISCOSITY OF LIQUIDS SOME SIMPLE EVERYDAY IDEAS 'Everything should be as simple as possible,but not simpler',Einstein English rheology words:viscosity,consistency,and texture Thick,creamy,watery,runny Gluey,gelatinous,sticky,tacky,gooey,gummy,cohesive kitchen laundry liquids,surface cleaning liquids ● bathroom cabinet personal products ● garage oils,greases pantry sauces,salad dressings ● tool shed paints,glues,mastics
English rheology words: viscosity, consistency, and texture Thick, creamy, watery, runny Gluey, gelatinous, sticky, tacky, gooey, gummy, cohesive
Sugars ·Flavours ·Polysaccharides ●Vitamins ·Lipids ●Preservatives ·Proteins ·Minerals ●Colours 。Water
Having considered the consistency of a product,we now need to think about its packaging and means of delivery.These probably range over the following sequence of packaging,consistency and delivery action: Package Consistency Action Example pressure cans thin and watery Spray paint,hair spray bottles,cans oily Squirt washing-up liquid,oil tubes pasty Squeeze toothpaste,tomato paste tubs soft-solid like Scoop face cream, Clearly anyone interested in these areas should be thinking very carefully about rheology
WHAT IS FLOW AND DEFORMATION? Insufficient facts always invite danger,Captain',Mr Spock SHEAR FLOW 4—。 0◆ Adjacent particles moving over or past each other original shape EXTENSIONAL FLOW ←-00→ I Adjacent particles moving away from or towards each other T 1 Particle motion in shear and extensional flows