ISO 3616:2022

Textile glass - Chopped-strand and continuous-filament mats - Determination of average thickness, thickness under load and recovery after compression

This document specifies a method for the determination of the average thickness, the thickness under load and the recovery after compression of chopped-strand and continuous-filament textile-glass mats.

Verre textile — Mats à fils coupés et mats à fils continus — Détermination de l'épaisseur moyenne, de l'épaisseur sous charge et de la recouvrance après compression

La présente Norme internationale spécifie une méthode de détermination de l'épaisseur moyenne, de l'épaisseur sous charge et de la recouvrance après compression de mats de verre textile, à fils coupés et à fils continus.

General Information

• Status: Published
• Publication Date: 18-Dec-2022
• ICS: 59.100.10 - Textile glass materials
• Technical Committee: ISO/TC 61/SC 13 - Composites and reinforcement fibres
• Drafting Committee: ISO/TC 61/SC 13 - Composites and reinforcement fibres
• Current Stage: 6060 - International Standard published
• Start Date: 19-Dec-2022
• Due Date: 05-Oct-2023
• Completion Date: 19-Dec-2022

Relations

• Revises: ISO 3616:2001 - Textile glass - Chopped-strand and continuous-filament mats - Determination of average thickness, thickness under load and recovery after compression
• Effective Date: 06-Jun-2022
• Revises: ISO 3616:2001/Amd 1:2017 - Textile glass - Chopped-strand and continuous-filament mats - Determination of average thickness, thickness under load and recovery after compression - Amendment 1
• Effective Date: 06-Jun-2022

Overview

ISO 3616:2022 specifies a standardized test method for measuring the average thickness, thickness under load, and recovery after compression of textile glass reinforcement mats - specifically chopped‑strand mats and continuous‑filament mats. The procedure defines specimen preparation, conditioning, measurement apparatus (dial micrometer and two calibrated steel plates), and calculation rules so results are reproducible and suitable for process and quality control in composite manufacturing.

Key Topics

• Scope: Method applies to chopped‑strand and continuous‑filament textile‑glass mats used as reinforcement in polymer matrix composites.
• Specimen preparation: Cut test samples and specimens using templates (e.g., 316×316 mm or 400×250 mm samples; specimens 158×158 mm or 200×125 mm) following ISO 3374 sampling guidance.
• Conditioning: Condition specimens for at least 2 hours in a standard atmosphere per ISO 291; testing atmosphere must match conditioning.
• Apparatus:
  • Dial micrometer readable to 0.01 mm with ≥70 mm stem.
  • Polished steel plate A (light plate) and plate B (heavy plate) with specified areas and masses to apply nominal light and heavy pressures (or equivalent hydraulic system).
  • Positioning jig and stand for repeatable alignment.
• Procedure: Measure stack thickness under light pressure (plate A), under heavy pressure (plate A + plate B), and after specified recovery interval following removal of heavy load.
• Calculations & expression:
  • Average thickness (mm) = (h1 − h2) / n; express to three significant figures.
  • Thickness under load and recovery after compression expressed as percentages of average thickness; express to two significant figures.
• Test report requirements: Include reference to ISO 3616:2022, material ID, specimen dimensions, conditioning, apparatus details, and averaged results.

Applications

• Quality control and acceptance testing of textile glass mats used as reinforcement in composite parts.
• Process design and tooling specification in composite manufacturing (hand lay‑up, resin infusion, molding) to predict final laminate thickness and part dimensions.
• Supplier specification and comparison: ensures consistent reporting of average thickness, thickness under load, and recovery after compression.
• Relevant to industries using glass‑fiber reinforcements: marine, automotive, aerospace, wind energy, and construction.

Related Standards

• ISO 291 - Standard atmospheres for conditioning and testing (conditioning requirements).
• ISO 3374 - Reinforcement products - Mats and fabrics - Determination of mass per unit area.
• Prepared by ISO/TC 61 (Plastics), SC 13 (Composites and reinforcement fibres).

Keywords: ISO 3616, textile glass, chopped‑strand mats, continuous‑filament mats, average thickness, thickness under load, recovery after compression, composite manufacturing, test method.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 3616
Third edition
2022-12
Textile glass — Chopped-strand
and continuous-filament mats —
Determination of average thickness,
thickness under load and recovery
after compression
Verre textile — Mats à fils coupés et mats à fils continus —
Détermination de l'épaisseur moyenne, de l'épaisseur sous charge et
de la recouvrance après compression
Reference number
© ISO 2022
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Published in Switzerland
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
6 Preparation of test specimens . 4
7 Conditioning of test specimens . 4
8 Procedure .4
9 Calculation and expression of results . 5
9.1 Average thickness . 5
9.2 Thickness under load . 6
9.3 Recovery after compression . 6
10 Test report . 7
iii
Foreword
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13,
Composites and reinforcement fibres.
This third edition cancels and replaces the second edition (ISO 3616:2001), which has been technically
revised. It also incorporates the Amendment ISO 3616:2001/Amd. 1:2017.
The main changes are as follows:
— an “Introduction” has been added;
— the sampling method (former Clause 6) has been deleted and subsequent clauses have been
renumbered;
— the duration for conditioning test specimens has been changed to from at least 16 h to at least 2 h.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
Chopped-strand and continuous-filament mats are mainly used as reinforcement materials for polymer
matrix composites. The average thickness, thickness under load and recovery after compression of the
mat are the most basic parameters provided for the composites process design and the final product
structure and size design.
v
INTERNATIONAL STANDARD ISO 3616:2022(E)
Textile glass — Chopped-strand and continuous-filament
mats — Determination of average thickness, thickness
under load and recovery after compression
1 Scope
This document specifies a method for the determination of the average thickness, the thickness under
load and the recovery after compression of chopped-strand and continuous-filament textile-glass mats.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 291, Plastics — Standard atmospheres for conditioning and testing
ISO 3374, Reinforcement products — Mats and fabrics — Determination of mass per unit area
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
average thickness
thickness of a mat, in millimetres, measured in accordance with the specified method, under a specified
nominal light pressure
Note 1 to entry: The average thickness determined by this met
...