Seam strength

ISO 10321 Geosynthetics Tensile Test for Joints/Seams by Wide-Width Strip Method. 

ASTM D4884 Standard Test Method for Strength of Sewn or Bonded Seams of Geotextiles. 

The seam strength of a GTX is mainly relevant for bags or containers made of GTX-N or GTX-W in marine applications or for containers for the dewatering of slurry Ailed in containers. The seam efficiency shall be sufficient to be able to withstand the loads, eg, when the container or bag will be dropped into the sea. For such products the seam strength is an essential characteristic (Table 7.5 and Fig. 7.7). 

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Diverse appHcations for the fabric sometimes demand specialized tests such as for moisture vapor, Hquid transport barrier to fluids, coefficient of friction, seam strength, resistance to sunlight, oxidation and burning, and/or comparative aesthetic properties. Most properties can be deterrnined using standardized test procedures which have been pubHshed as nonwoven standards by INDA (9). A comparison of typical physical properties for selected spunbonded products is shown in Table 2. 

PS heat-sealable film has extensive use in different marketable products with its major emphasis in packaging. They produce good sealing seam strength, tear resistance, and tear propagation strength. 

Seam strength is often referred to as seam efficiency, which is an expression of seam strength as a function of fabric strength. 

Seam strength does not only apply to stitched seams but also to non-stitched seams whether they are bonded or welded. In a research paper by Hayes and McLoughlin (2007), the relationship between welded and stitched seams is examined and statistical analysis is used to compare their properties. 

This stitch formation consists of one needle thread and two looper threads with the looper threads forming a purl on the edge of the fabric (Figure 6.28). The needle thread provides the seam strength and the looper threads provide cover on the edge of the fabric that prevents frayed edges and creates a neat appearance on the seam. 

As part of the stitching process, it is very important to have the correct stitch density for the garment this has a direct influence over seam strength, seam appearance and seam extensibility. The factors affecting stitch density are ... 

Seam strengths in uniaxial tests parallel to the threads... 

Determination of seam strength at 23°C at the seam width established by the fabric manufacturer ... 

The quality of the seam depends on its strength, elasticity, durabihty, stabihty, and appearance. These characteristics can be measured by seam parameters such as seam strength, seam pucker, seam shppage, seam appearance, and seam damage. Each of these parameters is influenced by various material and machine variables, and can be quantitatively measured. 

If a double-layer hollow area of the fabric is surrounded by a joint weave, the borderline between the two could be regarded as a woven seam. Unfolding of this hollow area can be done, for example, by inflating, and this may require a certain level of seam strength. The details of weave design have a significant influence on the strength of woven seams. 

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