Association study between basis weight distribution of melt-blown web and air velocity distribution on the collector

Abstract

Basis weight distribution of melt-blown fibrous web is attracting considerable interest because it directly affects the application performance of nonwovens. Basis weight distribution is strongly determined by the air velocity distribution on the top surface of the collector. However, how the mentioned air velocity distribution affects basis weight distribution is still unknown. Measurement of the mentioned two distributions is the first step to investigate the influence mechanism. Thus, this work measures air velocity distribution on the collector under different processing conditions. Then the fibrous web is fabricated under same conditions. After fabrication, the basis weight distribution of fibrous web is analyzed by using image analysis method. The effects of processing conditions, including velocity of air jet and suction, die-to-collector distance, and pore size of the collector, on the air velocity distribution and basis weight distribution are quantitatively analyzed. The results demonstrate that higher suction speed and air jet velocity, smaller die-to-collector distance, and larger pores of the collector result in higher air velocity on the top surface of the collector. On the other hand, higher suction speed and air jet velocity, larger die-to-collector distance, and smaller pores of the collector create evenly distributed basis weight. In addition, the correlation between basis weight distribution and air velocity distribution is discussed based on the Spearman correlation analysis method. High correlation demonstrates that air velocity and basis weight display similar distribution on the collector. Namely, both of air velocity and basis weight in the central zone are larger than those in the fringe zone on the collector.

Formation Mechanism of Fibrous Web in the Solution Blowing Process

“…Continuous filaments fell on the moving collector and covered the thin part of the MD during SB. We have mentioned the uniformity difference of the basis weight in the MD and CD during MB in our previous work. − In this study, we also found a similar distribution of the basis weight during SB.…”

“…In this study, the air velocity should be simulated in advance. In some of the published simulations, − the fluent module of ANSYS software was employed to simulate the air velocity. To simulate the fibrous web on the collector, once the free end of the solution reached a given XY plane (a hypothetical collector), its XZ coordinates and diameter were frozen, whereas its Y coordinate was varied following the translational motion of the collector in the Y direction.…”

“…The model achieved its solution in an iterative algorithm using MATLAB software. We have provided the solution protocol in our previous articles. − To calculate the structural parameters of the fibrous web, the program should export the fiber position on the collector, as well as the fiber mass and diameter. The solution procedure of these numerical equations has been reported in our previous work − and is not discussed in this article (Table ).…”

Modeling and experimental study of pore structure in melt-blown fiber assembly

“…Herein, the air velocity and temperature were simulated in advance. In some published works [19][20][21][22], the Fluent module in the ANSYS software was employed to simulate the air velocity and temperature. However, most MB air flow simulations usually involve high-speed air jets.…”