Standard Test Methods for Tensile Testing of Aramid Yarns
Theory:
ASTM D7269 covers several variations of procedures for testing aramid yarns and Kevlar type fibers. Aramid material was originally developed by Stephanie Kwolek at Dupont. The term stands for "aromatic polyamide".
There are several types of forms that these fibers can come in including individual fibers, wound yarns, cordage, and fabrics. Each type of sample requires a different type of grip.
Geometry:
The geometry of aramid or kevlar material can vary based on which stage in the manufacturing process it is in. Small, individual fibers can be tested as well as full woven fabrics.
Solution:
Several types of grip solutions can be used to test under this specification. In the video, wedge grips are used to test a thin strip of aramid material that will be used inside a racing tire.
If a longer piece of fabric is to be tested, the wrap grip is a much better solution. Individual fibers can be tested using our Wind Fixtures for small cordage, yarns and fibers.
Analysis:
Calculations for ASTM D7269 include Ultimate Tensile Strength and Elongation. Several other types of specification tabulations can be analyzed. They are laid out in the official ASTM publication.
Similar Specifications:
ASTM D885
ASTM D2970