H1: Seam slippage

Seams sometimes give way completely, even though the stitching remains intact, and a hole in the seam results. If an undesired opening suddenly occurs under tensile load in the seam area of the fabric, the problem is “seam slippage”, which can be seen on the following pictures.

Bild/Grafik 1: Bad seam slippage Foto kommt von Herrn Esche

The cause for this occurrence is not, as often assumed, the seam or the sewing thread, but the fabric itself that shows poor seam slippage behavior. This means that the warp and weft threads of the fabric only have little adhesion towards each other and thus, shift each other. The cause for this can either be the fabric finishing (e.g. special anti-slippage finishing), or the construction of the fabric (e.g. linen weave, twill weave, satin weave). These parameters can only be optimised by the fabric manufacturer.

Bild/Grafik 2: Poor fabric slip-resistance

Within the context of a testing procedure that was specially developed by AMANN, different processing parameters were tested and compared with fabrics that tend to seam slippage regarding their effect on seam slippage. The seam strength recommendations of Euratex TCG (Technical Clothing Group) and DTB Produktinfo (Dialog Textil Bekleidung) served as the basis for this testing procedure. In none of the cases, the desired level of strength could be achieved. With the following measures, seam slippage may be minimised.

Use of a suitable stitch type: o 301 lockstitch

o 401 double chainstitch

Bild/Grafik 3: Stitch type 301Bild/Grafik 4: Stitch type 401Hinweis Adextra: Kein Bilduntertitel, da Beschreibung (z.B. 301 lockstitch) bereits im Text

Use of a suitable seam type: o double felled seam

o safety seam (Stitch type 401+504)

Bild/Grafik 5: Double felled seam Bild/Grafik 6: Safety seam (stitch type 401+504)Hinweis Adextra: Kein Bilduntertitel, da Beschreibung (z.B. double felled seam) bereits im Text

Secure closing seams by additional topstitching or, e.g. o fold seam allowance on one side and topstitch

o Unfold seam allowances and topstitch on both sides

Bild/Grafik 7: Additional topstitching 1

Bild/Grafik 8: Additional topstitching 2Hinweis Adextra: Keine Bildunterschrift, da bereits im Bullet Point genannt

Before sewing, bonding of the seam line with an inlay

Bild/Grafik 9: Bonding of the seam line with an inlay

Seam allowance of at least 1 cm width Stitch density of at least 4 stitches/cm / 10 stitches/inch Possibly additional serging of the individual layers as a protection for the seam edges

These measures my affect the feel of the seams, their appearance, and lead to increased production costs.

H2: Summary

The cause of seam slippage is usually in the fabric and can be only corrected in collaboration with the fabric manufacturer. With further working steps and ideal processing parameters, the seam grinning can be maybe slightly improved, but not fully eliminated. Moreover, it needs to be considered that any additional production efforts also lead to higher production costs at the same.

To achieve the best possible sewing result, it is recommended to conduct individual tests first. The AMANN Sewing Technology Center is available for further information or concrete recommendations.