BS EN ISO 3376_{Leather. Physical and mechanical tests. Determination of tensile strength and percentage extension}

Test summary

This International Standard specifies a method for determining the tensile strength , elongation at a specified load and elongation at break.  It is applicable to all types of leather.

Test apparatus

Force testing stand with suitable loadcell capable of measuring displacement while applying a constant speed of grip separation.  Complimentary software for recording load and displacement and calculating results.

Grips with minimum length of 45 mm in the direction of the load designed to apply a constant clamping force by mechanical of pneumatic means.

Cutting apparatus

A thickness guage

Preparation

From the sample, cut at least six test pieces to the dimensions given in the standard with the long axis parallel to the backbone, and six test pieces perpendicular to the backbone.

Measure the width and thickness of each test piece as instructed in the standard and calculate mean values for the width and the thickness of the sample.

Test method

Set the jaws of the grips to 50 mm separation for standard size test pieces, or 100 mm separation for large size test pieces, and clamp the test piece securely.

Record the initial grip separation, and start the test stand moving at a constant speed of grip separation at 100 mm/min.

Continue applying force at a constant speed until the sample breaks

Determine the tensile length (Tn) as calculated from:

Tn = F/w.t

  Where

    F = highest force recorded

    w = mean width in mm

    t = mean thickness in mm

Percentage elongation at a specified load (El)

El = (L1-L0/L0) x 100

  Where

    L1 is the separation of the jaws at the specified load

    L0 is the initial separation of the jaws

Percentage elongation at break (Eb)

El = (L2-L0/L0) x 100