ISO 1890:2009 Overview
ISO 1890:2009 is an international standard established by the International Organization for Standardization (ISO) that specifies a precise method for determining the twist in reinforcement yarns made from textile glass, carbon, aramid, or other reinforcement fibres. This standard is applicable to both single yarns (one twist) and folded or cabled yarns (two or more twists), primarily focusing on package-wound yarns.
The method outlined is crucial for quality control, product consistency, and performance validation in composites and reinforced materials manufacturing. Twist measurement is essential for understanding yarn properties that affect the mechanical behavior of composite materials.
Key Highlights:
- Applicable to single, folded, and cabled yarns.
- Primarily applies to package-wound yarns; indicative results for yarns from warp beams or fabrics.
- Not suitable for staple fiber products.
- Based on removal of twist by untwisting a standardized specimen length.
- Covers yarns made from glass, carbon, aramid, and other reinforcement fibers.
Key Topics in ISO 1890:2009
Scope and Applicability
- The standard covers reinforcement yarns comprising continuous filaments of varied materials such as glass, carbon, and aramid.
- Instructions address the measurement on package-wound yarns, with caveats on measurements from warp beams or fabric.
- Staple fiber products are excluded due to their structural differences.
Measurement Principle
- Twist determination is conducted by untwisting a yarn specimen until all filaments lie parallel.
- Twist is expressed in turns per meter based on the number of turns removed.
- Direction of twist is classified per ISO 2:1973 into Z twist or S twist.
- The method accounts for different take-off systems, emphasizing the tangential take-off to avoid twisting errors.
Testing Apparatus and Specimens
- Requires a twist tester equipped with clamps, providing precise measurement of turns and specimen length.
- Use of dissection needle or thin blade and magnifying glass aids in verifying full twist removal.
- Specimens should be taken consecutively from elementary units or laboratory samples, with standard length guidelines.
- Conditioning is generally not required, but testing in standard atmospheres (ISO 291) is recommended for dispute resolution.
Test Procedure
- Yarn tension adjustment is recommended but not mandatory for single yarns.
- The yarn is taken off tangentially from the package, clamped under just taut tension, and untwisted.
- Twist direction and value are recorded for at least three specimens, allowing calculation of average twist.
Results and Reporting
- Twist is calculated as the ratio of turns removed to yarn length under test.
- The report must include yarn identification, test conditions, twist values, and any deviations from the standard procedure.
- Enables consistent data reporting and comparability across laboratories and production batches.
Applications of ISO 1890:2009
- Ensuring quality control in the production of reinforcement yarns used for composites.
- Designing composite materials with predictable mechanical performance based on yarn twist properties.
- Supporting research and development in textile reinforcements for aerospace, automotive, construction, and sporting goods industries.
- Assisting manufacturers in verifying yarn specifications and maintaining process control.
- Facilitating supplier and customer verification through standardized testing.
By providing a uniform method to quantify twist, ISO 1890:2009 helps streamline the manufacturing process, minimize defects, and optimize composite reinforcement properties.
Related Standards
- ISO 2:1973 - Textiles - Designation of the direction of twist in yarns and related products: Defines terminology used for twist direction (Z or S).
- ISO 291 - Plastics - Standard atmospheres for conditioning and testing: Details the standard environmental conditions for conducting tests.
- ISO 1889 - Reinforcement yarns - Determination of linear density: Relevant for determining yarn linear density, which may be needed alongside twist measurement.
Adhering to ISO 1890:2009 in conjunction with these standards ensures comprehensive characterization of reinforcement yarns for advanced composite applications.
