Three-dimensional mesh fabric is a special type of knitted spacer fabric with sandwich structure consisting of two separate meshed multifilament outer layers linked together with a layer of spacer monofilaments. Nowadays, many sells and buyers would like to call it Sandwich mesh fabric because it can better be understood by people. 

It has found wide applications in home textiles and automotive industry due to its good energy-absorbing performance and ventilation property. 

The real geometric structure was reconstructed by scanning the fabric via Micro X-ray computed tomography. The spacer monofilaments and meshed outer layers were analyzed quantitatively based on the Micro X-ray computed tomography reconstruction. 

It was found that the spacer monofilaments are different in length, curvature, and torsion. The spacer monofilament lengths can be ranging from 9.43 to 10.77 mm. Their curvatures varied from around 0.1 to 0.3 mm⁻¹. The torsions of spacer monofilaments can be positive and negative with different directions of twisting and had a certain degree of symmetry between two adjacent wales. The monofilament loops in the outer layers also varied in height, width, and enclosed area. Three-dimensional mesh fabric is a periodic but highly inhomogeneous structure.