The document discusses calendering in rubber manufacturing, explaining the function of calenders and the challenges associated with achieving accuracy, particularly focusing on calender roll floating. It outlines the causes of inaccuracies, the disadvantages of roll floating, and presents a solution involving a preloading device to mitigate this issue. References include notable texts and web resources on calendering technology.

1. L. D. COLLEGE OF
ENGINEERING
RUBBER TECHNOLOGY
Sub:- r.e.(rubber engineering)
1Prepared By:-Yogesh Malani

2. Name:-Yogesh Malani
Topic:-Calender Roll Floating
Guided By:-Prof. A.D.Bhatt
Prof. P.C.Chavda
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3. Content
 What is calender??
Difficulties to achieve accuracy in
Calendering
Calender Roll Floating
Disadvantages of calender roll floating
Solution for Calender roll floating
References
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4. 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
Coating
Laminating
Profiling
Embossing
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5. 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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6. Calender Roll Floating
Calender Machine
Calender Roll Floating 6Prepared By:-Yogesh Malani

7. 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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8. 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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9. 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.
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10. 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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11. 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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12. References
Calendering 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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