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ABC's of Package Tests : Tensile and elongation

The testing machine consists of clamps to hold the sample, some means of gradually increasing the load on the specimen until it breaks and indicators which show the load and the amount of elongation.


To perform the test, measured, gauged speciments are clamped into the testing machine and streteched until the break. Tensile strenth is usually reported in Kilo Newton per meter necessary to pull the papaer spart. For films, the usual units are kgs per sqcm of original cross-sectional area. Tensile strength is quite literally the amount of force necessary to pull a material apart. The elongation is the amount a material will stretch before breaking.


Tensile strength is a most important value for materials used in applications such as heavy-duty bags. A large value for elongation is an index of toughness, since it indicates a material will absorb a large amount of energy before breaking.