Review this brief list of calendering terms and definitions

General terms

Back side

Side opposite to the front; side facing away from the reel or windup.

Cigarette holder (crane lift extension tubes)

Special calender roll lifting tools; typically used in supercalenders. These tools are placed onto the ends of the roll shaft before lifting the roll in/out of the stack.

Cross machine direction

Side to side movement, along the face of the roll; from the tend side to drive side or the drive side to tend side.

Drive side (DS)

Side of machine with main drive.

Front side

Windup or reel side of the calender; side facing outgoing paper; lead-out side of calender.

Inboard

Between the frames.

Inside

Typically used with supercalenders to identify threading platforms. Synonymous with "front side"; windup or reel side of the calender; side facing outgoing paper; lead-out side of calender.

Lead-in rolls

Carry rolls, spreader rolls, etc. which lead the web from the previous machine into the calender.

Lead-out rolls

Carry rolls, spreader rolls, etc. which lead the web out of the calender and into the next machine.

Machine calender

An on-line calender. Typically consists of all hard rolls.

Machine direction

Movement forward or back along the web path.

Off machine (off-line)

The calender stack section is combined with an unwind and windup/reel, and is located independently from any paper machine. The group of three machines can also be referred to as the calender.

On machine (on-line)

The calender stack section is a single machine within a paper machine or coater line. On-machine calenders do not have an unwind or windup.

Outboard

Outside the frames.

Outside

Typically used with supercalenders to identify threading platforms. Synonymous with "back side"; side opposite to the front; side facing away from the reel or windup.

Steam shower

A device used to apply steam to the paper as it enters nips of the calender stack.

NOTE: A steam shower located in the pocket between a calender stack roll and its corresponding fly roll may be referred to as a "pocket" steam shower.

Stack

The calendering section of the calender. Although this term is typically used to refer to a vertical stack of 3 or more rolls, this term will also be used for single nip calenders.

Tend side (TS)

Side opposite the main drive. Typical location for operator controls and operator access.

Threading platform

A moveable platform, typically located on a supercalender, and used to reach the stack section for threading or maintenance. May be accessed by stationary platforms.

Temperature control system terms

Process water

De-mineralized boiler quality water (like condensate) which is pumped through the rolls in a closed loop system to heat, cool, or distribute the temperature of the rolls. Refer to supplier datasheets for specifications.

Mill water

Typical mill cooling water; non-processed water which is typically used to cool the process water. Heat is transferred from the process water to the mill water within a heat exchanger, then returned to the general mill circulation.

Steam

Typically, 150 PSI steam at less than 465 °F. Steam is typically used to heat the process water in a heat exchanger. It may also be used as a direct heating medium in some calender designs.

Condensate

Water created from cooling steam.

Oil

A heat transfer fluid which is pumped through the rolls in a closed loop system to heat or cool the rolls. Refer to supplier datasheets for specifications.

NOTE: The type of "oil" is selected specifically at design time and may not be substituted with any other variety or warranties will be voided.

Cooler

A heat exchanger which cools the process water or oil by transferring the heat to mill water.

Chiller

A refrigerating unit.

Heater

Depending on the system:

• A heat exchanger which heats the process water using steam.
• An electric heater which heats the oil.

Frame Design terms

C type

Calender configuration in which the windup and unwind stands are on the same side of the calender stack.

Z type

Calender configuration in which the windup and unwind stands are on opposite sides of the calender stack.

In-line

Calender configuration in which the windup and unwind stands are on opposite sides of the calender stack but in the same horizontal plane.

Open-face

Rolls in the calender stack are guided by ways, one on each end of the roll.

Closed-face

Rolls in the calender stack are guided by ways, two (2) on each end of the roll.

For more information on calender terminology or assistance with calender maintenance, contact your Valmet representative.