Understanding Nonwoven Technical Specifications: Tensile, MD/CD, MVTR

A deep dive into reading and evaluating a technical data sheet (TDS). Master breaking strength, elongation at break, wicking time, and air permeability test methods.

Decoding the Technical Data Sheet (TDS)

When purchasing industrial or medical roll goods, the Technical Data Sheet (TDS) serves as the primary engineering contract between supplier and buyer. Knowing how to interpret these parameters ensures you receive the correct material performance.

Critical TDS Parameters Explained

• Tensile Strength at Break (N/5cm): Tested under ISO 9073-3 / ASTM D5035 using constant-rate-of-extension (CRE) tensometers. Represents the maximum pulling force a 50mm strip withstands before tearing. Higher values mean higher durability on high-speed converting machinery.
• Elongation at Break (%): The percentage stretch before rupture occurs. Cross-lapped spunlace typically exhibits 30-45% in MD and 60-85% in CD, offering flexibility without snapping.
• Air Permeability / Frazier (L/m²/s): Measures volume of airflow through the fabric under specified pressure drop (ISO 9237). Critical for breathable medical drapes and filtration media.
• Moisture Vapor Transmission Rate (MVTR): Measures grams of water vapor escaping per square meter over 24 hours (g/m²/24h). Essential for wound dressings to prevent skin maceration.

Ensuring Standard Test Methods

Always check which testing body standard is referenced on the TDS: ISO (International), EDANA/INDA (Global Nonwovens Association), or ASTM (American Standards). Compare values only under identical test conditions (such as clamp width and pulling speed).