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ASTM D3826 Tensile Test Degradation End Point in Degradable Polyethylene & Polypropylene

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ASTM D3826 is a standard test method that determines the tensile properties of a plastic sample before and after degradation. Degradation is an important property for plastics because it determines how much time is needed to recycle a material.

What Is ASTM D3826?

ASTM D3826 measures a degradation end point, or brittle point for degradable polyethylene and polypropylene films and sheeting. Brittle point, in testing degradable polyethylene and polypropylene film is that point in the history of a material when 75% of the specimens tested have a tensile elongation at break of 5% or less.

What Other Standards Relate to Testing Thin Film & Sheet Plastic?

ASTM D882 tensile test of thin film plastic to monitor tensile elongation during the degradation process.

Why Use a Standard Test Method Like ASTM D3826?

ASTM D3826 is useful for support of engineering design and development, to confirm internal quality assurance, to compare one material versus another, to provide a clear specification for commercial transactions, and to provide insights for first time test developers.

What Test Machines Are Recommended for Plastic Thin Film & Sheet?

Our universal test machines serve multiple plastic testing applications and are capable of performing virtually all quasi static tension/compression tests, such as tensile, peel, and adhesion. Our machines feature a uniform constant rate of extension (CRE), or constant velocity control mode, with a speed range between 1 and 500 mm/min (0.04 to 20 in/min). Force measurement complies with ASTM E4. Consider the 240 family test machine for higher speeds and extended crosshead travel applications.

The majority of rigid plastics tests can be performed at loads under 4.5 kN (500 lbs).

What Grips Are Recommended for Testing Thin Film & Sheet?

Contact line grips have faces designed to concentrate the entire gripping force along a single line perpendicular to the direction of testing stress.

Plastic film tensile tests of parallel strips generally need a grip that features contact line jaws where one side features a radius contact line across the width of the test sample, accompanied with a flat surface jaw. In the case of fragile film, a rubber coating is used on the smooth jaw.

Pneumatic grips are popular in the cases where the sample shrinks as it is pulled, requiring the jaws to adjust automatically. In the case of rigid film, a mechanical vise grip may suffice. Spring loaded eccentric rollers are the most popular because they feature contact line jaw with a spring loading that adjusts automatically.

Mechanical Vise Grips are affordable solutions featuring a wide variety of interchangeable jaws and accessories. Most mechanical grips feature a side opening vise design with smooth, serrated, and corrugated (wave) surface jaws.

For this application consider our G227 model. Also consider our G7 eccentric roller model.

Pneumatic Vise Grips offer ease of sample loading, consistent clamping force, self alignment, and interchangeable jaws with smooth, serrated, and corrugated (wave) surfaces. For this application, consider our G149 pneumatic vise grips.

Important Considerations When Testing per ASTM D3826

The tensile elongation property determined by ASTM D3826 is of value for the characterization of degradable materials. Tensile elongation can vary with specimen thickness, method of preparation, speed of testing, type of grips used, and manner of measuring test extension. Consequently, where precise comparative results are desired, these factors must be carefully controlled.