Interlock stitch

A needled felt, on the other hand, is a fabric composed of natural, synthetic, or a combination of natural and synthetic fibers physically interlocked by the action of a needle loom with or without combination of other textile fabrics and with or without suitable combination of mechanical work, chemical action, moisture, and heat, but without weaving, knitting, stitching, thermal bonding, or adhesives (16). 

A machine with approximately 1000 needles continuously produces a fabric 5-m wide. The assembly process is more complex, slower, and more expensive than tufting. The pile yam and stitch yam are inserted into the knitting needle, and the stuffer yam is interlocked with the others through a separate feed mechanism of the machine. As with tufting, the loops of the pile fabric formed are sHt, creating the desired individual blades. 

The four-thread overlooking stitch 514 exhibits very good strength due to the nature of its formation and interlocked properties. When the seam is put under tensile pressure, the interconnected nature of this stitch formation exhibits high strength and resistance to force thus being able to withstand excessive energy placed upon the seam. 

Stitching two layers of fabric together in interlocked 3D loops is an old technique, long used to make 3D garments but adaptable to technical products. Pieces are cut to the required shapes and sewn together to make a 3D form. 

Structures Unidirectional (roving, yam) Nonwoven (felts, papers, filament wounded or placement) weave (plane, triaxial) hi- and triaxial braides knitted Z-pinned, needled punched, stitched Tridimensional braids, 3D weave (orthogonal, angle interlock, multilayer), nD multi axial weave... 

They create stitches by interlocking the upper thread (from a spool that winds through the needle) with the lower thread (that comes up through the bobbin). 

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