Elongation at Break

property

The percentage increase in length of a plastic specimen at the point of tensile failure, measured from original length to final length before breaking during a tensile test.

In Simple Terms

Think of elongation at break as how much you can stretch a plastic sample before it snaps. A material with 500% elongation can stretch to five times its original length before breaking, while one with 5% elongation is quite brittle and breaks with minimal stretching.

Why It Matters

This property determines if a resin can handle bending, stretching, or impact without breaking. High elongation materials work well for flexible packaging and films, while low elongation indicates rigidity suitable for structural parts.

Technical Details

Measured per ASTM D638 using standardized test specimens under controlled strain rates. Calculated as ((final length - original length) / original length) × 100%. Values range from <10% for rigid materials like PS to >500% for flexible materials like TPE. Temperature and strain rate significantly affect results.

Real-World Examples

LLDPE film grade evaluation

A blown film processor requires LLDPE with >600% elongation at break to ensure the film can withstand bag filling and handling without tearing during packaging operations.

Rigid PVC compound selection

A pipe manufacturer specifies PVC with 50-80% elongation at break to provide sufficient toughness while maintaining rigidity for structural integrity in plumbing applications.

TPU grade comparison

An automotive supplier evaluates TPU grades with 400-800% elongation at break for airbag covers, ensuring the material can stretch adequately during deployment without premature failure.