Some common defects in spunbond nonwoven fabric making machine include:
Yarn or fiber breakage
If the fiber or yarn breaks during spinning, it can lead to spots or thin areas in the fabric. It reduces the thickness and strength of the fabric.
Uneven fabric thickness
If the fiber spinning process is not uniform across the web width, it can result in variations in fabric thickness and basis weight. This impacts properties like softness and strength.
Pin holes or tears
Small holes or tears in the fabric can develop due to damaged spun fibers, improperly entangled fibers or mechanical abrasion during processing. This can allow fine fibers to escape.
Loose fibers
Extra loose fibers protruding from the fabric surface can irritate the skin or get tangled. This is a sign that the fibers are not properly bonded together.
Lint
Short fibers or fiber fragments left on the fabric surface are undesirable and can be easily shed. Proper filtration and cleaning is needed.
Non-uniform fiber distribution
If the fiber feed rate or opening of the spinnerets is not properly controlled, it leads to variations in the number and diameter of fibers across the web width. This influences properties like thickness, softness and strength.
Fabric non-uniformity
Issues with the spinning process, fiber feeding or web formation can ultimately result in variations in basis weight, thickness, fiber distribution across the web width leading to a non-uniform fabric.
Pilling
Small fiber balls on the surface of the fabric form due to mechanical abrasion and rubbing. This is an issue for fabrics subjected to high stresses. Proper fiber selection and entanglement can reduce pilling.