Melt Blowing: Equipment, Technology, and Polymer Fibrous Materials

ISBN-13: 9783642627859 / Angielski / Miękka / 2012 / 212 str.

L. S. Pinchuk; VI a. Goldade; A. V. Makarevich

Opis

One of the recently emerging techniques of fibrous materials production, melt blowing, consists of forming fibers from substances heated above their melting (crystalline) or glass transition (glass-like) point with further blowing by gas flow. The sprayed fibrous mass is then cooled to solidification either in a gas flow or upon deposition on the forming substrate. Realized from polymers and then ceramics, the melt blowing technique has enriched materials science, engineering, and all commodity products by novel types of fibrous materials and products made from them with a unique combination of properties. The reasons for the popularity of melt blowing are the following. The shape stability and strength of melt-blown materials and products are controllable technological parameters that depend on the diameter and the intensity of the adhesive interaction between fibers and the number of contacts between them. The greater area of fiber surface in contrast to negligible clearances in between is the source of the uniqueness of melt-blown materials as systems whose properties are governed to a great degree by surface phenomena. Dielectric materials manufactured by melt blowing are subjected to the rigorous effects of heat, deformation, and friction during processing which is accompanied by natural electrical polarization of fibers. The fibers are transferred into an electret state (an electret is a dielectric that preserves its electrical polarization for a long time), which makes melt-blown materials the source of a permanent electrical field.

Spis treści

1. Introduction (Historical Review).- 2. Melt Blowing Techniques.- 2.1 Main Technological Procedures.- 2.2 Modern Trends in Melt mowing Techniques.- 3. Equipment.- 3.1 Spray Heads.- 3.1.1 Basic Designs.- 3.1.2 Modified Heads.- 3.2 Auxiliary Equipment.- 4. Structure of Melt-Blown Polymer Fibrous Materials (PFM).- 4.1 Major Structural Parameters.- 4.2 Effect of Different Technological Regimes on PFM Structure.- 5. Specific Properties of Melt-Blown PFM.- 5.1 Physicochemical Characteristics.- 5.2 Electret Charge in Melt-Blown Materials.- 6. Fibrous Materials in Filtration Systems.- 6.1 Efficiency of Filtration Systems.- 6.2 Filtration Mechanisms.- 6.2.1 Mechanisms of Particle Precipitation.- 6.2.2 Surface and Depth Filtration.- 6.2.3 Electrostatic Precipitation.- 6.2.4 Precipitation and Coagulation in a Magnetic Field.- 7. Electret Filtering PFM.- 7.1 Mechanism of PFM Polarization.- 7.2 Capillary Phenomena.- 7.3 Production Process and Properties of Electret PFM.- 7.4 Applications.- 8. Magnetic Filtering PFM.- 8.1 Backgro.- 8.2 Simulation of Magnetic Deposition in PFM.- 8.3 Theory versus Experiment.- 8.4 Magnetization of PFM.- 8.5 Magnetic Coagulation of Particles in PFM.- 8.6 Magnetic Capillary Phenomena.- 8.7 Serviceability of Magnetic PFM-Based Filters.- 9. Adsorptive and Microbicidal PFM.- 9.1 PFM Modified by Porous Adsorbents.- 9.2 PFM as Adsorbents of Oil Product8.- 9.3 Complex-Forming PFM.- 9.4 Adsorptive-Microbicidal PFM.- 10. PFM as Carriers of Microorganisms.- 10.1 Biofilters with Polymer Fibrous Biomass Carriers.- 10.2 Effect of Magnetic Fields on the Growth Proce8ses of Microorganisms.- 11. Other Applications of PFM.- 11.1 Household Uses.- 11.2 Industry.- 11.3 Construction.- 11.4 Medicine.- 11.5 Packing.- 11.6 Protection of Products and Environment.- 12. Ecological and Social Problems.- 12.1 Solution of Ecological Problems.- 12.1.1 Purification of Indu8trial Gases.- 12.1.2 Wa8tewatcr Purification.- 12.1.3 Melioration.- 12.1.4 Oil and Chemical Sorbents.- 12.2 Regeneration, Utilization, and Burial.- 12.3 Economic Estimates.- 13. Conclusion.- References.

Blurb

This book is devoted to a nontraditional class of materials which are manufactured by the melt-blowing process - i.e. by extrusion of polymer melt followed by fiber stretching with a gas stream. For the first time extensive data on classical and modern modifications of this technology are generalized and a review is given of extrusion head dies and subsidiary equipment. The text examines the structure and main properties of melt-blown materials as conditioned by peculiarities of overheated polymer melt spraying in oxidizing medium. Information is given about filtering mechanisms and the main types of polymer fibrous filtering materials: electret, magnetic, adsorptional, bactericidic and about carriers of microorganisms in biofilters. Social and ecological aspects of the application of melt-blown materials are analyzed.