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L. D. COLLEGE OF ENGINEERING

RUBBER TECHNOLOGYSub:- r.e.(rubber engineering)

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Name:-Yogesh Malani

Topic:-Calender Roll Floating

Guided By:-Prof. A.D.Bhatt Prof. P.C.Chavda

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Content

What is calender??Difficulties to achieve accuracy in CalenderingCalender Roll FloatingDisadvantages of calender roll floatingSolution for Calender roll floatingReferences

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What is calender??

Calender is a machine having two, three or four revolving rolls, which are

fixed on a frame and used in Rubber manufacturing likes, Sheeting CoatingLaminatingProfilingEmbossing

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Difficulties to achieve accuracy in Calendering

1.Calender related Causes Calender bowl deflection Calender roll floating Variation in calender roll temperatures

2.Coumpound Related Causes Variation in feed stock temperatures Variation in compound volume flow Variation in compound viscosity Compound composition.

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Calender Roll Floating

Calender Machine

Calender Roll Floating

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Calender Roll Floating

This problem is particularly observed with vertical stack calenders having plain journal bearings.

Bearing require larger clearances than roller bearings to operate.

Clearances is necessary because the allowance for expansion due to rise in temperature must be provided.

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Calender Roll Floating• Roll float up or down, within the bearings

clearances.

• It occurs that because the balance of nip forces and roll weight.

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Calender Roll Floating

• The magnitude of floating increases with the increase in bearings wear.

• The roll float is at maximum in the triangular and horizontal “Z” configurations.

• Nip forces act in planes at 90° to each other.Z

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Disadvantages of calender roll floating

• Its occurs to the variation in the rubber sheet.

• Due to its weight, floating roll causes more difficulties to the softer compounds.

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Solution for Calender roll floating

Preloading Device:-• By using this device top roll of the

calender is held at the top the bearings by hydraulic pressure while calendering, to reduce roll “floating”.

• Particularly useful for soft compound sheet

accuracy.

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ReferencesCalendering Technology by :

Arun V. Apte http://www.google.com/ http://www.wikipedia.com/ http://www.youtube.com/ http://www.ggengg.com/

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