By means of this high-performance stitch-bonding machine for additional mechanical bonding, three-dimensional nonwovens with a double-sided plain-knit exterior surface (spacer nonwovens) and high production output can be produced. When Kunit nonwovens are fed, the fibres oriented inside perpendicular to the fabric run essentially contribute to excellent properties as regards air permeability and compressive elasticity. Thanks to the combination of various materials as well as the possibility of partial stitch formation only, a wide variety of variants can be obtained.