Tensile Specification
International test method defines the methodology for testing the tensile properties of plastic films and sheets with a thickness of less than one millimetre. Adherence to iso 527-3 ensures that manufacturers and converters use the same parameters to measure the strength of flexible packaging. This consistency allows for the comparison of different polymer blends or laminated structures.
The standard covers the determination of breaking force and elongation at break.
Test Observation
Information gathered during the test reveals how a film will behave when subjected to the stresses of a filling line. Under the rules of iso 527-3, a universal testing machine pulls a strip of material at a constant speed until it fails. Sensors record the load and the change in length throughout the duration of the pull.
These values are used to calculate the stress and strain curves for the material.
Physical Preparation
Accuracy depends on the careful cutting of the test strips to avoid nicks or rough edges. The iso 527-3 protocol specifies several types of test pieces, including rectangular strips and dumbbell shapes. Cutting dies or laser cutters are used to produce uniform samples that meet the required dimensions.
Any imperfection in the sample edge acts as a stress concentrator and leads to a false low reading. Conditioning the samples in a controlled environment before testing is also a requirement. High quality blades are necessary to ensure the edges are smooth and free from micro tears.
