Why is the zip is curved/humpy after pressing?
Spiral/coil zips have an S twist and Z twist in the teeth creating a “smile” or “frown” appearance when the teeth are joined. The left and right teeth should be both in the same direction/condition. If this is not the problem check the sewing tension is equal on both sides of the zip. Also check […]
Why are sewn coil zips sometimes called nylon zips?
Previously these zips may have been made from a range of manmade materials like nylon, polyester, polypropylene, poly butyl phthalate (PBT). Nylon was a common material used for zips due to its smoother feel and so this remained as a name for this category of zips.
Can Coats test results be used for all footwear brands?
No, each major brand normally has own test procedures and requirements. However, for brands that request tests under ISO test procedures then Coats test results can be used. Coats labs are also able to perform tests following major brands’ test procedures and requirements.