improvements through material development• characteristics are consistent throughout the material...

Improvements Through Material DevelopmentENGINEERED ELASTOMERIC MATERIALS

© ABBA Roller, LLC, 2012—Presented at AIMCAL 2012 Technical Conference


AGENDA

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What Is Rubber?

Dual Durometer Cover

Summary

Single Durometer Cover

Hybrid Material Cover


• Rubber is a spring– Governed by the same laws of

vibrations, dynamics, and physics as a coil spring would be

– F=k*x• F = Force• k = spring rate (think of durometer)• x = displacement/deflection

– For a linear spring, durometer is analogous to spring rate

WHAT IS RUBBER?

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• Based upon usage on a roll, a rubber cover acts like a compression spring– Common types of compression springs

• Linear/Constant• Progressive• Progressive with knee• Degressive• Dual Rate

• Just like there are multiple types of springs, there are many types of rubber covers

• The demands/requirements of the process will determine the type of spring needed

WHAT IS RUBBER?


• Durometer affects the characteristic– Acts either like linear spring or slightly

progressive

• General roll applications– Most processes will work fine with a single

layer of a constant durometer material– Consistent web material

• Durometer is varied for process control

SINGLE DUROMETER COVERCharacteristics

SINGLE DUROMETER COVERMultiple Durometer Comparison


80 Durometer60 Durometer40 Durometer

Forc

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Displacement

• Characteristics are consistent throughout the material

• Transitions will occur when loads increase to the point where the core starts to influence the spring rate– Compared to an elastomeric material the core has an

infinite spring rate– Cover thickness needs to be adjusted so the desired

influence is achieved

SINGLE DUROMETER COVEROverview


DUAL DUROMETER COVERCharacteristics

• Acts like a linear spring with knee• General roll applications

– Used primary when large variations in web thickness occur– Process requires the ability to change between spring rates with small

changes in displacement

• The ratio of thicknesses are used to control the desired effective rate


Soft Rate Firm Rate

DUAL DUROMETER COVEROuter Cover Thickness Variation


Displacement

Forc

e

• Test was conducted with a cover thickness such that the effects of the core were not introduced

• All samples had the same initial spring rate to the same displacement– The cover thickness only effected the spring rate after

the transition point• For thin covers, the difference in ratio

performances will mean that a process might not be able to handle a lot of wear or regrinds

DUAL DUROMETER COVEROverview


HYBRID MATERIAL COVERCharacteristics

• Hybrid materials are a combination of compounds mixed to provided customized characteristics

• Multiple compound options– Can be compounded to act like a Dual Durometer or even

a variable durometer cover– Different elastomeric materials can be combined to adjust

for physical, chemical, or exposure requirements


HYBRID MATERIAL COVER


Displacement

Forc

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• Advantages of Engineered Materials– The “knee” in the spring rate can be customized to

meet different applications– The characteristics are homogeneous throughout the

material– The roll is able to be reground without effecting the

rate characteristics unlike a Dual Durometer

HYBRID MATERIAL COVEROverview


SUMMARY


• There are an unlimited amount of options when it comes to rubber coverings.– Not limited by single durometers or even

dual durometers• Your process might not lend itself to a

standard material, but there is a material that can be formulated for it!

THANK YOU!


Contact InformationDevin FrostABBA [email protected]

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