UPF Rating Setting It Correctly on a Tech Pack
UPF Rating should be written into the tech pack with a value, a tolerance and a method. This removes ambiguity from quotations.
Definition to agree
ultraviolet protection factor of fabric. Working figures for UPF Rating normally sit around UPF 50+ blocks over 97.5% UV in mainstream production. Note AATCC 183 or EN 13758 on the tech pack so nobody tests against an older revision.
Target value
Open the specification at UPF 50+ blocks over 97.5% UV, adjusted to the end use. Record elastane content alongside UPF Rating, because blends shift the measured value. A result outside UPF 50+ blocks over 97.5% UV usually points to process drift rather than to the fibre itself.
Method line
Always pair the target with AATCC 183 or EN 13758 so the mill and the laboratory test the same way. Keeping reference values for UPF Rating lets suppliers quote without extra sampling rounds. Ask for conditioning details together with AATCC 183 or EN 13758, since both affect the reading.
Tolerance line
State plus or minus limits to keep production realistic while protecting the requirement. Working figures for UPF Rating normally sit around UPF 50+ blocks over 97.5% UV in mainstream production. Note AATCC 183 or EN 13758 on the tech pack so nobody tests against an older revision.
Approval step
Approve the result on pre-production bulk rather than on development fabric only. Record elastane content alongside UPF Rating, because blends shift the measured value. A result outside UPF 50+ blocks over 97.5% UV usually points to process drift rather than to the fibre itself.
