Effect of inter-needle distance on jet roping and laydown structure in solution blowing

Here, a model lab-scale solution blowing setup was developed. Experiments were carried out in a model situation of two needles at several inter-needle distances and air velocities to investigate jet roping. Polymer jets issued from two needles were employed at the inter-needle distances of L = 4.5, 4, 3.5, 3, and 2.5 mm. Polymer jet intersections and merging near the needle tip and at a distance of ∼150 mm from the needle tip and near the collector were recorded employing a high-speed camera. The laydown images captured for each inter-needle distance were analyzed using scanning electron microscopy to link the laydown morphology to roping, which stems from the polymer jet–jet intersection in flight.