Quality Tests

Testing is conducted at each of our European mills in accordance with recognised industry standards.

Isolated measurements are not sufficient to detect problems in time; it must be supported through continuous, reliable testing and analysis. Each of our mill is equipped for process and paper testing, with dedicated teams present 24 hours a day. This way we can guarantee high quality paper performance.

Testing climate

It is important to have a well-defined testing climate to ensure the reliability and repeatability of the different tests. The liners and flutings are moisture sensitive. Their strength and stiffness properties are dependent on the ambient temperature and relative humidity. Small changes in the moisture content of the sheet affect the paper properties considerably. The standard testing climate is 23°C and 50% relative humidity. Before testing, the sheets are pre-conditioned at 30% relative humidity for 24 hours. They are then conditioned in the testing climate according to ISO 187.

We also perform testing at high relative humidity, particularly for materials used in humid conditions such as wet strength liner. For lifetime testing, humidity is cycled between 30% and 90% relative humidity several times.

Compression strength properties are very sensitive to moisture variation. For example, if the moisture content of the material is increased by 1% the compression strength decreases by approximately 8%. A 1% change in the material's moisture content is associated with a change in relative humidity from 50% to 60%

Common properties and methods

A selection of our tests, methods and related procedures have been provided for you below. We also develop new methods when needed, for example, the lifetime measurements.

Mechanical properties

  • Bursting strength
  • Short Span Compression Test, SCT
  • Ring Crush Test, RCT
  • Tensile strength and stiffness
  • Z-strength
  • Scott Bond (Ply Bond)
  • Concora Medium Test, CMT
  • Corrugated Crush Test, CCT
  • Bending resistance
  • Fracture toughness

Surface properties

  • Roughness PPS
  • Roughness Bendtsen
  • Brightness and colour
  • Friction
  • Dennison
  • Taber
  • Cobb
  • Optical Profile Tester, OPT

Other properties

  • Basis weight
  • Caliper
  • Moisture
  • Ash content
  • Fibre orientation
  • Formation
  • Air Permeance Gurley
  • Air Permeance Bendtsen

Special properties

  • Hygro expansion
  • Creep measurements
  • Cracking
  • Z-toughness, DCB
  • Flexo printing
  • Tapio
  • TSO tester

Corrugated properties

  • Box Compression Test, BCT
  • Sagging
  • Corner compression tester
  • Edgewise Crush Resistance Test, ECT
  • Flat Crush Resistance Test, FCT
  • Bending stiffness
  • Torque test
Paper mills across Europe