Figure 1.

Schematic of the area under investigation (for samples 2–4; for sample 1 an additional row of 4 squares was added). The white nanofiber mat is spun on the light-blue PP nonwoven, where the spinning area is restricted at the top and bottom by the borders of the PP substrate, and at the left and right side by the geometry of the spinning chamber and the substrate speed. The left and right borders are usually thinner due to the decreasing electric field in these areas.