The Art of Owning & Operating Rubber Calenders

| CALENDERS |
2. Increase the temperature by 5 degrees
Celsius when you stop the rolls.
loop. In this condition the roll surface
temperature is below the water temperature.
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Because this helps to maintain a more
uniform roll surface temperature.
You need to realize that the TCU
(Temperature Control Unit) of your rubber
calender controls the temperature of the
water exiting the rolls and not the 'roll
surface temperature'. This is an important
distinction.
Visualize these two scenarios –
Scenario 1 – When the calender is not
processing rubber (i.e. during warm-up and
when the calender is stopped), the roll
surface is losing heat to the atmosphere.
Here, the TCU is actively heating the water
Scenario 2 – When the calender is running
and processing rubber, heat is being
generated. Here, the TCU is cooling the water
loop. In this condition the roll surface
temperature is above the water temperature.
From the above, you will realize that for a
constant water circuit temperature, the roll
surface temperature swings (above & below
the water temperature) between the
calender normal running condition and
when the calender is stopped. This
difference in roll surface temperature
means that your rubber compound is being
processed under varying conditions.
Shrinkage and other properties of your
processed compound will therefore vary.
Image Source: Pelmar Engineering Ltd.
Rubber & Tyre Machinery World | JUL 2016