Netspinning

Netspinning is a polymer processing technique for forming net-like structures by extrusion through specially patterned spinnerets to create a mesh rather than a simple filament. The technique uses the principle of forming many filaments in a predefined arrangement that join at nodes, resulting in a two-dimensional net or a three-dimensional mesh as the polymer solidifies.

The process can employ different polymer states depending on the material: melt spinning for thermoplastics, or dry and wet spinning for solutions. A patterned spinneret deposits multiple filaments in a coordinated pattern, which are then drawn, cooled or coagulated, and often heat-set or crosslinked to stabilize the net geometry. Post-processing steps such as stretching, bonding, or lamination may be used to adjust pore size, porosity, and mechanical properties.

Materials commonly used in netspinning include various polymers such as polyolefins, polyamides, and polyesters, chosen for their solution or melt behavior and for the desired balance of strength and porosity. The geometry of the spinneret and the processing conditions determine the mesh size, filament thickness, and the distribution of junction strengths within the net.

Applications of netspun nets span several sectors. In filtration and membranes, nets act as supports or carriers for selective layers. In geotextiles and erosion control, nets provide reinforcement and drainage pathways. In agriculture and horticulture, they serve as shade or trellis components. Medical and tissue engineering uses include scaffolds with interconnected porosity, while industrial nets can function in packaging or protective coverings.

Netspinning is distinguished from traditional knitting, weaving, or braiding by its reliance on extruded filaments arranged in a net pattern through a spinneret, enabling high controllability of pore architecture and lightweight, high-porosity materials.