ISO/TS 23927:2024

Laminates and moulding compounds - Prepregs - Determination of tack

This document specifies the test method for determining the tack in prepregs under defined conditions. This document is applicable to but not limited to unidirectional and multidirectional thermoset based prepregs made with glass fibres, carbon fibres, aramid fibres and other similar fibres included.

Stratifiés et composés à mouler — Préimprégnés — Détermination du tack

General Information

• Status: Published
• Publication Date: 21-Mar-2024
• ICS: 83.120 - Reinforced plastics
• Technical Committee: ISO/TC 61/SC 13 - Composites and reinforcement fibres
• Drafting Committee: ISO/TC 61/SC 13/WG 2 - Laminates and moulding compounds
• Current Stage: 6060 - International Standard published
• Start Date: 22-Mar-2024
• Due Date: 09-Dec-2023
• Completion Date: 22-Mar-2024

Overview

ISO/TS 23927:2024 - "Laminates and moulding compounds - Prepregs - Determination of tack" is a Technical Specification that defines a reproducible, quantitative test method for measuring the tack of thermoset-based prepregs (unidirectional and multidirectional) made with glass, carbon, aramid and similar reinforcement fibres. Published in 2024, it provides apparatus, specimen, conditioning and procedural requirements to obtain consistent tack measurements suitable for quality control and automated production.

Key Topics and Requirements

• Definition of tack: Tack is the maximum retracting (separation) areal force measured when a defined probe is pulled away from the prepreg surface; expressed in Newtons (N).
• Apparatus:
  • Probe: 304 stainless steel, 80 mm diameter, flat end machined at 90°, surface roughness ≤ 500 nm (≤ 250 nm RMS per ISO 21920-2), hardness ≥ 80 HRB; self-aligning probe recommended.
  • Support platen: same material as probe, at least 1.5× specimen size (≥ 100 × 100 mm), flatness deviation ≤ 0.01 mm over 100 mm.
  • Force measurement system: inertia-free, compliant with Class 1 of ISO 7500-1.
  • Tension/compression testing machine: meet ISO 7500-1 requirements; data acquisition frequency sufficient for accurate force/time capture.
• Specimens and conditioning:
  • Specimen size: 100 × 100 mm (±2 mm).
  • Minimum five specimens from the same roll; more can be used for precision (95% confidence per ISO 2602).
  • Condition per ISO 291; preferred atmosphere (23 ± 2) °C and (50 ± 10) % RH; conditioning time ≥ 4 h (or as agreed).
• Test cycle (compression/dwell/retraction):
  • Compress to (900 ± 10) N at 1 mm/min.
  • Hold compression for (100 ± 1) s (dwell).
  • Retract at 25 mm/min and record force–time curve; maximum retracting force = tack.
• Specimen seating and cleanliness: use thin-film double-sided tape or equivalent; probe cleaned with a solvent that leaves no residue; protective film handling guidance included.

Applications and Users

• Practical use cases:
  • Quality control of prepreg batches.
  • Process control for automated layup, AFP/ATL, and automated manufacturing where tack affects placement and consolidation.
  • R&D and material comparison for composite suppliers and OEMs (aerospace, automotive, wind energy, sporting goods).
• Typical users:
  • Test laboratories, composite material suppliers, manufacturing engineers, and QA/QC teams involved in prepreg handling and assembly.

Related Standards

• ISO 291 - Standard atmospheres for conditioning and testing
• ISO 7500-1:2018 - Verification of static uniaxial testing machines (force measurement)
• ISO 21920-2 - Surface texture: profile method (surface roughness parameters)

ISO/TS 23927:2024 delivers a standardized, quantitative tack test that improves repeatability and supports both manual and automated prepreg manufacturing workflows.

Standards Content (Sample)

Technical
Specification
ISO/TS 23927
First edition
Laminates and moulding
2024-03
compounds — Prepregs —
Determination of tack
Stratifiés et composés à mouler — Préimprégnés —
Détermination du tack
Reference number
© ISO 2024
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
5.1 Probe .3
5.2 Support platen .3
5.3 Force measurement system .3
5.4 Tension/compression testing machine .4
5.4.1 General .4
5.4.2 Test speed .4
5.4.3 Recording of data .4
6 Test specimens . 4
7 Number of test specimens . 4
8 Conditioning . 4
9 Procedure . 4
9.1 Test atmosphere .4
9.2 Probe setting .4
9.3 Specimen seating .4
9.4 Test .5
9.4.1 General .5
9.4.2 Contacting the specimen .5
9.4.3 Measurement of the tack force.5
10 Expression of result . 6
10.1 Tack .6
10.2 Tack strength .6
11 Test report . 6
Annex A (informative) Determination of tack — Example . 7
Annex B (informative) Example of a probe and a self-aligning jig. 8
Bibliography .10

iii
Foreword
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iv
Introduction
Tack is an important property of prepregs that relates to the integrity of the composite laminate being
produced. The practice of determining tack in prepregs is mostly qualitative as it is often done by the
experience of the personnel involved. On the other hand, in some automated manufacturing using prepregs,
tack needs to be measured as a part of the manufacturing process. This document is intended to provide
standing alone quantitative method for the measurement of tack in prepregs.

v
Technical Specification ISO/TS 23927:2024(en)
Laminates and moulding compounds — Prepregs —
Determination of tack
1 Scope
This document specifies the test method for determining the tack in prepregs under defined conditions.
This document is applicable to but not limited to unidirectional and multidirectional thermoset based
prepregs made with glass fibres, carbon fibres, aramid fibres and other similar fibres included.
2 Normative referenc
...