Seam Strength Setting It Correctly on a Tech Pack
Seam Strength should be written into the tech pack with a value, a tolerance and a method. This removes ambiguity from quotations.
Definition to agree
force needed to break a sewn seam. Working figures for Seam Strength normally sit around above 100 N specification in mainstream production. Note ISO 13935-2 grab method on the tech pack so nobody tests against an older revision.
Target value
Open the specification at above 100 N specification, adjusted to the end use. Record elastane content alongside Seam Strength, because blends shift the measured value. A result outside above 100 N specification usually points to process drift rather than to the fibre itself.
Method line
Always pair the target with ISO 13935-2 grab method so the mill and the laboratory test the same way. Keeping reference values for Seam Strength lets suppliers quote without extra sampling rounds. Ask for conditioning details together with ISO 13935-2 grab method, since both affect the reading.
Tolerance line
State plus or minus limits to keep production realistic while protecting the requirement. Working figures for Seam Strength normally sit around above 100 N specification in mainstream production. Note ISO 13935-2 grab method 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 Seam Strength, because blends shift the measured value. A result outside above 100 N specification usually points to process drift rather than to the fibre itself.
