Fiber Motion near the Collector during Melt Blowing: Part 2 — Fly Formation

Abstract

On-line and off-line measurements were obtained to gain an understanding of fly production during multi-hole melt blowing at commercial speed. These measurements allowed us to describe the effects of common processing parameters on fly production and develop a model for fly formation that begins to account for experimental measurements.

Fiber and web formation of melt‐blown thermoplastic polyurethane polymers

“…On the other hand, the air velocity was measured at 50 cm from the die without polymer extrusion with 60% opening of the air valve, and on the basis of the experimental study of the MB PP process, air velocity was calculated with mathematical models. For the fiber‐ and web‐formation study of the MB TPU process, the sigmoidal curve of logged data fit was used on MB PP experimental data sets 12, 13…”

“…Air temperature and speed were measured by a Series 471 digital thermo‐anometer produced by Dwyer (Chicago, IL), and the die temperature was measured by an IR thermometer MX2 provided by Rasytek (Santa Cruz, CA). The TPU fiber velocity and temperature during the MB process were calculated on thebasis of a polypropylene (PP) fiber velocity and air velocity spin line study by Breese and Qureshi 12, 13…”

“…The concept of the melt‐blown (MB) process was first introduced in 1956 through a Naval Research Laboratory project initiated by Wente to produce filters composed of microfibers for collect radioactive particles from the atmosphere during the early years of the cold war 1–12. Zhao2 reported that only 20 U.S.…”

“…The most important advantage of the MB process is that, fundamentally, all thermoplastics polymers can be processed by MB technology 3, 4, 8. Recently, elastomers, including thermoplastic polyurethanes (TPUs), have been a focus of MB research because of their unique properties, including high elasticity in all directions, good shore hardness for a given modulus, high abrasion/chemical resistance, excellent mechanical/elastic properties, low stress relaxation, and resistance to long‐term cyclic flex failure 11–19…”

“…Although numerous studies have been performed to determine the relationships between the MB process and the product parameters of polyolefin polymers, additional studies are needed to understand the melt blowing of TPUs and to make further improvements in MB TPU web performance properties 12, 13…”