Strength Evaluation for Polyester Film

Figure 1 Overview of the SHIMADZU Autograph Model AG-X

●Introduction
Functional polymer films offer excellent mechanical, electrical and thermal properties. As a result, widespread applications continue to be developed, including everything from packaging to electronics materials.
The Shimadzu precision universal testers (Autograph AG-X series) and other materials strength testers are capable of multifaceted evaluations for the mechanical properties (particularly strength and elongation) of these polymer films.
This report introduces a static tensile test (generally a low speed test) of a dumbbell-shaped (regular sample shape) polyester film. The tensile speed was changed, and the polyester film’s tensile strength and elongation quantity were measured.

●Static Tensile Test

[Sample]

(1) Sample:

Polyester film

(2) Sample shape:

Dumbbell shape

(3) Sample dimensions:

Total length 70 mm, Flat region 15 mm (W) x 20 mm (L) Depth 0.038 mm

 

[Load Conditions]

(1) Tensile speed:

600 mm/min

(2) Distance between chucks:

40 mm

(3) Ambient conditions:

Room temperature 26 °C

(4) Tester:

Autograph AG-X (Fig. 1)

(5) Test force measurement:

500 N load cell

(6)Displacement measurement:

Tester crosshead movement

(7) Data sampling interval:

50 ms

Diagram of Stress Versus Displacement

●Test Results
The sample was gripped at both ends by flat resin plate grips, and the tensile test was performed under the abovementioned conditions. The results are shown in Fig. 2 as a diagram of stress versus displacement.
An extensometer was not used for these measurements. Instead, sample elongation was obtained from the tester crosshead movement (indicated by piston displacement in Fig. 2). These results show that the tensile strength is 138 MPa, and the elongation at time of fracture is approx. 31 mm.