The following relates to fabric calenders, both textile and steel cord only. Localized cord disturbance in cord distribution does not usually affect fabric weight, whereas overall cord distribution … [Read more...]
A Consistent Mill Feed Will Substantially Reduce Gauge Variations
September 9, 2008
A consistent feed to the calender will substantially reduce gauge variations. Consistent, uniform, dwell times on the break down and feed mills, as well as consistent bank size, will result in … [Read more...]
Calender Speed Changes Result in Undesirable Gum Wall Thickness Changes
September 8, 2008
When the calender is running there are forces generated that try to separate the rolls. These separating forces are proportional to calender speed, although the relationship is not linear. The … [Read more...]
Increase Roll Temperature when the Calender is Stopped
September 8, 2008
Increase the temperature by 20 to 40 degrees F when the rolls are stopped to maintain a more uniform roll surface temperature. The TCU (Temperature Control Unit) controls the temperature of the water … [Read more...]
Keep your Calender Running During Warm-Up and Cool Down
September 8, 2008
Severe thermal run-out can be introduced during warm-up of the calender if it is not kept running. Remember that the calender gap will be reduced as the rolls grow (get larger) as their temperature … [Read more...]
Limit Force Induced Gauge – Keep the Calender Running
September 7, 2008
Keep the calender running – stops cause the rolls to become egg shaped and introduce significant gauge thickness variation. When the calender is stopped, roll heat loss is not uniform around the … [Read more...]
Force Induced Calender Gauge Variations
September 7, 2008
Force induced variations result from the way the calender is operated and from previous process steps such as feed mill operation compound consistency from mixing In rubber calendering, … [Read more...]
Calender Roll End Actuator Wear -leads to inability to make small gauge corrections
September 7, 2008
Electric screw actuators are the most common type of calender roll end positioning system. The screw and nut operate under very high loads and thus experience significant wear even with proper … [Read more...]
More Calender Run-Out problems – Roll Water Passage
September 6, 2008
Most modern calender rolls are the drilled type. This means that water passages are drilled across the roll face under the surface. This effectively forms a radiator-like heat exchanger around the … [Read more...]
Calender Roll Surface Run-Out may actually be the bearings
September 6, 2008
Calender roll bearing smay have excessive run-out. The result is the same as, and will appear as calender roll surface run-out. Excessive bearing clearance will result in the roll shifting during … [Read more...]
