Glossary
Below are some definitions to terms commonly used in our industry. If you still need help, please contact us.- Bowl
General term for pressed fibre covered rolls. Derived from the word ‘bole’ meaning ‘trunk of a tree’. Wooden bowls (usually Sycamore) were originally used for textile calendering and squeezing.
- Calendering
A finishing process whereby a material (eg paper or textile) is passed between two or more rollers (which usually apply heat and pressure to the material) to improve its surface properties.
- Camber
The convexity of a roll. Many calendering applications utilise a positive camber on the rolls to compensate for deflection.
- Cotton Roll
General term for pressed fibre covered rolls with cotton or cotton paper based covers.
- Crowning
A positive camber on a roll.
- Cutting Down
The process of removing the old cover from a fibre covered roll.
- Deflection
The extent to which a roll bends under its applied load.
- Elasticity
The extent to which deformation of the roll cover material from an applied load is reversible (measured as Modulus of Elasticity). Increased elasticity promotes improved resilience (resistance to surface marking and damage).
- Embossing
The process of creating a three-dimensional effect or design in paper and other ductile materials. Many embossing applications utilise an engraved roll running against an elastic backing roll.
- Filled Roll
General term for pressed fibre covered roll.
- Filling
The process of recovering a fibre covered roll.
- Filling Material
The cover material of a pressed fibre covered roll.
- Linear Pressure
The force applied within the nip of a calender, usually measured in kg/cm or kN/m.
- Nip
The area of contact between two rollers.
- Nomex®
Heat resistant man-made fibre based calender roll cover material.
- Oiling Rolls
General term for rolls used to apply a thin and even layer of oil to the surface of sheet metals.
- Press
Hydraulic pressing machine, custom built for the compression of the fibre based cover material on fibre covered rolls.
- Pressing
The process of compressing the cover material on a fibre covered roll.
- Profile
The shape of a roll or cylinder measured by the change in diameter over its length.
- PU
Polyurethane.
- Resilience
The ability of the roll cover to resist and recover from surface damage.
- Roberto™
RHL’s patented high expression squeezing rollers.
- Supercalender
Machine utilising a stack of alternating steel and fibre covered rolls through which paper is passed to improve its density, smoothness and gloss.
- Superelastic
RHL’s high performance cover material for embossing backing rolls.
- Syncast™
RHL’s new generation Polyamide textile calender roll sleeves.
- Wiper Rolls
General term for rolls used to remove or control the amount of oil or emulsion on a metal substrate.
- Wringer Rolls
General term for rolls used to remove or control the amount of oil or emulsion on a metal substrate.