The tension, break, elongation, seal strength test, etc. of plastic film usually uses a strip sample, or dumbbell shape. For convenience sampling, a strip sample is more common. A strip sample cutter is suggested to take sample with width 10mm, 15mm, 25.5mm etc.
User can choose according to standard.
For soft material, such as stretching film, it can be put between two pieces of paper to form a “Sandwich” sample. The cutting can be from the top paper to get good samples.
The sample should be no nicks, no tears and wrinkles.
Reference standard: ASTM D882
According to ASTM D882 Standard Test Method for Tensile Properties of Thin Plastic Sheeting. The test specimens have below requirement.
- The test specimens shall consist of strips of uniform width and thickness at least 50 mm (2 in.) longer than the grip separation used.
- The nominal width of the specimens shall be not less than 5.0 mm (0.20 in.) or greater than 25.4 mm (1.0 in.).
- A width-thickness ratio of at least eight shall be used. Narrow specimens magnify effects of edge strains or flaws, or both.
- The utmost care shall be exercised in cutting specimens to prevent nicks and tears which are likely to cause premature failures (Note 6). The edges shall be parallel to within 5 % of the width over the length of the specimen between the grips.