DIN ISO 11093-8 E 2018-05 PDF

Full title and description

STB DIN ISO 11093-8 E 2018-05 — Paper and board — Testing of cores — Part 8: Determination of natural frequency and flexural modulus by experimental modal analysis. This document specifies a laboratory method that uses experimentally measured natural frequencies (free‑free transverse vibration) to determine the flexural (bending) modulus of cylindrical paper and board cores used for reels and winding applications.

Abstract

ISO 11093-8 specifies how to determine the flexural modulus of cylindrical paper and board cores by measuring their natural frequencies in free‑free transverse vibration and converting those measurements into a bending modulus. It applies to cores that meet specific dimensional criteria (internal diameter, minimum wall thickness and minimum length). The part notes the alternative three‑point method in ISO 11093‑7.

General information

• Status: Published – international standard (ISO 11093-8:2017). National adoptions available (e.g., DIN adoption). STB listing shown for the DIN ISO English edition.
• Publication date: ISO edition published 15 June 2017; national/DIN adoption published 2018 (DIN listing 2018‑10); STB entry dated 2018‑05.
• Publisher: International Organization for Standardization (ISO); national adoption/publishers include DIN for the German edition.
• ICS / categories: 85.060 (Paper and board).
• Edition / version: ISO edition 3 (ISO 11093-8:2017). DIN published/adopted version referenced as DIN ISO 11093-8 (2018). STB naming often follows national cataloguing of the DIN/ISO text.
• Number of pages: ISO original: 8 pages; DIN German edition: listed as 13 pages (national foreword/translations can add pages).

Scope

The standard applies to cylindrical paper and board cores whose dimensions fall within defined limits (internal diameter typically 50 mm to 350 mm; minimum wall thickness and minimum length requirements are specified). It covers measurement of natural frequencies in the free‑free mode of transverse vibration and calculation of the flexural modulus from those measurements. Non‑standard procedures (for example specialized pore‑pressure-type tests — not applicable here) are outside its scope; the part is intended for use in laboratory quality control, material characterisation and comparative testing of cores.

Key topics and requirements

• Determination of flexural (bending) modulus by experimental modal analysis (measurement of natural frequencies in free‑free transverse vibration).
• Dimensional applicability criteria: internal diameter range, minimum wall thickness (expressed as a function of diameter or absolute minimum) and minimum core length.
• Test setup and specimen handling to ensure free‑free vibration conditions and repeatable modal measurements.
• Conversion/calculation method to derive bending modulus from measured natural frequencies.
• Reference to alternative determination by the three‑point bending (ISO 11093‑7) for applications where that method is preferred.

Typical use and users

Primary users are manufacturers of paper and board cores, packaging and winding engineers, material testing laboratories, quality assurance and R&D groups in the paper and converting industries, and standards bodies implementing national/adopted versions (e.g., DIN). The method is typically used for product specification, incoming/outgoing inspection, design validation and comparative evaluation of core stiffness.

Related standards

ISO 11093 is a multipart series on testing of cores; the most directly related document is ISO 11093‑7 (Determination of flexural modulus by the three‑point method). National adoptions (DIN ISO 11093‑8) provide translated/publisher‑specific editions; other parts of ISO 11093 cover alternative tests and related procedures for core evaluation.

Keywords

paper cores, board cores, flexural modulus, bending modulus, natural frequency, experimental modal analysis, free‑free vibration, core testing, ISO 11093, DIN adoption, quality control.

FAQ

Q: What is this standard?

A: It is ISO 11093‑8 — a part of the ISO 11093 series that specifies a method to determine the flexural modulus of cylindrical paper and board cores using experimentally measured natural frequencies (experimental modal analysis). The ISO edition was published in June 2017; national adoptions (for example DIN) followed in 2018.

Q: What does it cover?

A: The standard covers test specimen dimensional limits, the free‑free transverse vibration measurement procedure, equipment and specimen preparation guidance, and the calculation procedure to convert measured natural frequencies into a flexural modulus. It does not replace or cover three‑point bending methods, which are described in ISO 11093‑7.

Q: Who typically uses it?

A: Paper/board core manufacturers, packaging engineers, independent test laboratories, R&D and QA teams in the paper converting industry, and national standards bodies implementing the ISO text as a national standard (e.g., DIN).

Q: Is it current or superseded?

A: The ISO edition ISO 11093‑8:2017 is published and listed as the active/confirmed international edition; national adoptions (DIN) were published subsequently (2018). Users should check national catalogues for the latest national publication or amendment status before purchase or citation.

Q: Is it part of a series?

A: Yes — ISO 11093 is a multipart series covering testing methods for paper and board cores; ISO 11093‑7 (three‑point method) is the most closely related standard for flexural modulus determination.

Q: What are the key keywords?

A: flexural modulus, bending modulus, natural frequency, modal analysis, paper cores, board cores, free‑free vibration, ISO 11093, core testing.