Unlocking the secret to reliable leather test results: the importance of proficiency testing in establishing metrological traceability

Leather is a versatile and widely used material, employed in various products such as fashion, footwear, furniture and automotive industries. The quality of leather products is critical in ensuring their safety, durability and aesthetic value verified through reliable and accurate testing. However, obtaining reliable leather test results can be challenging due to the complexity of the material and the test methods involved. Metrological traceability is a significant aspect of quality assurance, for ensuring results are comparable, consistent and accurate over time and across different laboratories. This paper will look at how the Polymer Laboratory of Kenya Bureau of Standards' Testing Services Department demonstrates metrological traceability of leather tear tests results.The Laboratory identified ISO 3377-1:2011 [IULTCS/IUP 40 Leather-physical and mechanical tests-determination of tear load. International Organization for Standardization, Geneva, Switzerland] as the appropriate reference measurement procedure for determination of tear load. Leather fibre material obtained from cowhide was tested for single-edge tear, result obtained was 6.6 +/- 0.7 N. This result was then compared to assigned value for tear (8.1 +/- 0.64 N) obtained through consensus of results from participating laboratories all using reference measurement procedure ISO 3377-1:2011|IULTCS/IUP 40 [8]. This comparison allowed the Laboratory to establish a traceability chain that connects its measurement result and any associated uncertainties to the SI unit of force, i.e. newton (N) through calibrated equipment.