D2838-18 – Standard Test Method Technical Guide

📐 Specimen Geometry and Types

The standard D2838−18 applies to heat‑shrinkable plastic film and thin sheeting. Strict geometric requirements govern the test specimens. Material thickness must be less than 1.0 mm (0.04 in.), while film (a sub‑category of sheeting) is arbitrarily defined as having a nominal thickness not greater than 0.25 mm (0.010 in.). Specimens are cut into strips with a clean, parallel width of 25.4 mm (1 in.) using the guidelines of Practice D6287. Conditioning of all test specimens must follow Practice D618 prior to testing.