Ask The Expert
Seam slippage minimum requirement
Dear Sylvia...hello...how are you?
I have received some recent test reports (based on ISO 13936 1 2004) whcih says 200newton on warp and 200newton on weft. But when I physically pull the fabrics at seam the yarns give way and windows are formed. I have noticed this phenomenon only on the pajamas as they are cut on straight grain. Underbust seams are stable and so are bias cut dresses. I would like to know about the minimum requirement of a woven satin and chiffon fabric in 100GSM to pass the seam slippage test. And what is the tolerance level? Thanks for your time. Regards...Parvez.
Hi Parvez, Difficult one to answer with out seeing the fabric and garment seams. I would say that EN ISO 13636-1 uses a basic 301(lockstitch type) seam with a 12 mm seam byte and is constructed with the seam running paralell to the warp and weft directions which will give you a worse case result. Iif the seam is running at a slight angle to the weave you will get a considerably higher results. Satin fabrics are known to be critical for seam slippage due to the weave construction likewise chiffon fabrics. Are you looking at production seams on the garment as opposed to laboratory produced seams? If you are, you will see a difference as it is probably not a 301 type seam and the byte may be considerable less than 12 mm, and the stitch density will be less. Typically a European Retailer would be looking for a minimum result of 80 N for a 6 mm seaming opening with a seam strength of 120 N based on the standard laboratory seam. The finishing process and seam construction are critical when cutting and designing these type of fabrics for the lingerie market. I would suggest you test the final garment seams using EN ISO 13936-2.
If I have not answered you question sufficiently please re contact. Sylvia