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Plastic Film Testing Guide: ASTM D882, D1938, D1894, F88, F1306 and D5458

Writer: Chris Thomas
Chris Thomas
4 days ago
3 min read

Plastic film and flexible packaging go through a standard set of mechanical tests: tensile strength and elongation, tear resistance, puncture resistance, coefficient of friction, seal strength and, for stretch wrap, cling. Each has its own ASTM method and fixture. This guide walks through the film tests most labs run and what you need to run them on one testing machine.

The core film tests

Tensile testing film to ASTM D882

D882 covers plastic sheeting and film less than 1.0 mm thick. Specimens are straight strips, typically 5 to 25.4 mm wide, with a 100 mm initial grip separation for general testing and 250 mm when tensile modulus is measured. Test speed is chosen from the material's expected elongation at break, so a brittle film and a stretchy film run at very different rates.

  • Grips: pneumatic grips with smooth or rubber-coated faces clamp evenly and avoid tearing at the jaw.

  • Specimen cutting: nicks on strip edges start premature breaks. Use a sharp cutter, not scissors.

  • Thickness: measure at several points; film thickness variation is a major source of scatter.

Tear resistance: ASTM D1938

D1938 uses a trouser-shaped specimen: a strip with a 50 mm slit down the middle. The two legs are clamped in opposite grips and pulled apart so the tear propagates along the specimen. The average force to propagate the tear is reported. It applies to film and sheeting up to 1 mm thick.

Coefficient of friction: ASTM D1894

D1894 measures static and kinetic friction of film sliding against itself or another surface. A sled about 63.5 mm square with a total weight of 200 g (1.96 N normal force) is pulled across a plane covered with film, and the friction force is measured. Static COF comes from the force to start motion, kinetic COF from the average force while sliding. A COF fixture mounts to a universal testing machine and converts vertical crosshead motion into horizontal sled travel.

Puncture: F1306 and D5748

F1306 pushes a small hemispherical probe slowly through clamped film and is common for medical and food packaging. D5748 is the stretch wrap version, using a rounded probe to simulate pallet-load corners. See our puncture testing standards comparison for details.

Seal strength: ASTM F88

F88 measures the force to peel apart a heat seal in 25 mm wide strips cut across the seal. The unsealed tails can be held unsupported, or supported at 90° or 180°, and the choice changes the result, so record which technique you used. Seal strength is reported as maximum and often average force per width, along with the failure mode (peel, tear, delamination).

Stretch wrap cling: ASTM D5458

D5458 measures how strongly stretch wrap clings to itself. A film strip is applied to a film-covered inclined plane and peeled off, and the peel force is reported as cling. Cling and puncture together describe how well stretch wrap holds a load.

One frame, many fixtures

All of these tests run on a low-capacity electromechanical universal testing machine or motorized force tester with a 100 N to 1 kN load cell. The difference is the fixture: pneumatic grips for D882, D1938 and F88; a COF fixture for D1894; puncture fixtures for F1306 and D5748; and an inclined-plane fixture for D5458.

Common mistakes in film testing

  • Jaw breaks from serrated faces: use smooth or rubber-coated faces on film.

  • Edge nicks: a single nick can halve measured elongation. Inspect strips before testing.

  • Wrong speed: D882 speed depends on elongation, and F88 allows a range. Record what you used.

  • Static charge and contamination in COF: handle film by the edges and condition specimens; fingerprints change friction.

  • Oversized load cell: many film forces are only a few newtons. Size the load cell for resolution.

Film testing FAQ

Can I use ASTM D638 for plastic film?

No. D638 is for plastics 1 mm thick and above, using dogbone specimens. Film and sheeting under 1 mm thick should be tested to D882 with straight strips.

What load cell do I need for film testing?

Most film tests need a 100 N to 1 kN load cell. Very thin films and COF tests may need even lower capacity for good resolution. Contact us with your materials and we will recommend a frame, load cell and fixtures.

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