What is ISO 5628 — Bending stiffness of paper and board about?
ISO 5628 is an international standard that deals with paper and paperboard. ISO 5628 specifies three test methods for determining the bending stiffness of paper and paperboard. The test methods differ in the type of loading mode, thus giving rise to the two-point, three-point, and four-point bending test methods.
ISO 5628 gives technical specifications terms, definitions, symbols, theory, different bending test methods, apparatus, sampling and preparation of test pieces, procedure, evaluation, and calculation and states the test reports for determination of bending stiffness.
Who is ISO 5628— Bending stiffness of paper and board for?
ISO 5628 on bending stiffness of paper and board is useful for:
- Paper and paperboard manufacturing companies
- Suppliers and distributors for paper and board
- Paper and pulp industries
- Laboratories for paper and board
Why should you use ISO 5628— Bending stiffness of paper and board?
Bending stiffness is regarded as an important property of paper and board, and many test methods have been used for its determination. For paper and board in the grammage range of 50 g/m2 to 500 g/m2, bending stiffness might vary by a factor of over 1000. This wide variation is reflected in the design of instruments intended for the measurement of this property.
ISO 5628 sets an approach to help you measure the bending stiffness and describes it in a consistent way, despite the variations in material type and instrument design. It can be used as the basis for preparing detailed methods for determining bending stiffness, using a particular instrument.
ISO 5628 defines the measurement conditions in such a way that the test piece is not subjected to any significant permanent deformation during the test, nor is the range of validity of the formulae for calculating the bending stiffness exceeded. It also recommends the users, the type of method suitable according to the thickness range of paper and board.
What’s changed since the last update?
BS ISO 5628:2019 supersedes BS ISO 5628:2012, which is withdrawn. This includes the addition of a note to clarify the measurement of F.