Handbook of Nonwoven Filter Media

Irwin M. Hutten

• Publisher: Butterworth-Heinemann
• Year: 2015
• eBook ISBN: 9780080983028
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Industrial & Technical Chemistry
• Index: Technology & Engineering

The Handbook of Nonwoven Filter Media, Second Edition provides readers with a fundamental understanding of nonwoven filter media. It is one of the few books dealing exclusively with the subject, and is primarily intended as a reference for people in the nonwovens industry (industry and academic researchers, technical, marketing , and quality control personnel) and universities offering courses in filtration theory and practice and nonwovens technology.The book includes applications for gas, liquid, and engine filtration, and identifies the types of filter media used in these applications. The various separation technologies that can be achieved with nonwoven filter media are revealed and discussed. Theoretical presentation is based on flow through porous media, and is developed around a nonwovens or engineered fabrics orientation. - Presents the latest information on legislative, regulatory, environmental and sustainability issues affecting the nonwovens and filtration industries - Includes a comprehensive discussion of Computational Flow Dynamics (CFD) by Dr. George Chase, University of Akron, USA - Includes the latest Global and North American marketing statistics for filters and filter media prepared by Brad Kalil of INDA

Chapter 1

Introduction to Nonwoven Filter Media

Abstract

Chapter 1 introduces the reader to nonwoven filter media. Applications are mentioned and market statistics are provided. Filtration, nonwovens, and nonwoven filter media are all defined. Various separation phenomena are identified and briefly described. Nonwoven filter media are classified by process and the various processes described.

Keywords

filtration; separation; nonwovens; filter media; filtration market statistics; filtration applications; nonwoven processes

1.1 Introduction

1.1.1 The challenges of filtration and separation

A filter medium is that part of a filter that does the filtering or that part of a separator that does the separating. Two important goals of filtration and separation are to protect humankind from the environment and the environment from humankind. People need fresh water to drink, clean air to breathe, and healthy foods for nutrition. Often, the only way to achieve these requirements for filtration and separation to remove the toxic and dangerous contaminants that are inherent in these sources. To illustrate, most of the water on earth is undrinkable ocean and seawater that can only be made drinkable by using separation techniques such as desalinization to remove the overabundance of salts and minerals. The filters in heat, ventilation, air conditioning (HVAC) systems help remove allergens, microbes, toxic compounds, and other chemical irritants from the fresh air we breathe and in so doing makes the air more breathable, healthy, and comfortable. Grown and processed foods often contain chemicals, biocides, and preservatives that by themselves are unhealthy for human consumption. The technologies of filtration and separation are often necessary to clean up these foods and make them safer, healthier, and more tasteful.

Yes, much of the contamination in the environment is natural; however, humankind does its fair share in contributing to this contamination. Human activities that are a serious source of the contaminants in our environment include waste discharges into our streams, rivers, and lakes; air contamination from the burning of fossil fuels; and disposal of solid waste. It is a big challenge of the Filtration and Separation Industry to develop the filtration and separation technologies that prevent the discharge of dangerous and undesirable contaminants into the environment. It is also a goal to protect people from contaminant dangers in the environment, whether they are annoying chemicals, toxic drugs, disease-causing microorganisms, and/or corrosive fumes.

Environmental and safety concerns and the issues of sustainability are major factors driving the use of filtration and separation technology and application. However, non-environmental problems are also a challenge to the Filtration and Separation Industry. Lube oil filters help automobile engines run longer and more efficiently. Tea bags and coffee filters provide the consumer with better tasting tea and coffee. In industry many chemical and pharmaceutical recoveries, separations, and purifications can only be accomplished with the right type of separation medium.

Fortunately, the Filtration and Separation Industry is rising to the challenge. New designs in filters and separation devices are dealing with the ever-increasing complexities of separating contaminants from a fluid stream. More and more filters are being made from recyclable polymers and biodegradable biomaterials. Filter media being introduced into the market place demonstrate new technologies to remove a variety of particles from fluid streams. This includes separation of particles of all shapes, sizes, and forms. As an illustration, Figure 1.1 shows the sizes of some of the various contaminants in air. Note the range of particle sizes vary from eye-visible beach sand particles that are as large as 1 mm (1000 µm) to particles of molecular and element dimensions that are less than 1 nm (0.001 µm). Some test dusts and aerosols are also shown in Figure 1.1 for comparison purposes¹.

Figure 1.1 The Sizes of Contaminants in Air. Reproduced with permission of Donaldson Company, Inc. All rights reserved.

Technologies for removing these particles extend beyond simple mechanical filtration, that is, the separation is something more than just trapping random particles in the matrix fibers of a nonwoven mat. Other separation technologies such as adsorption, electrostatic effects, coalescence, reverse osmosis, ion exchange, antimicrobial effects are playing more and more important roles in meeting the challenges of modern-day separations. New materials and filter designs are greatly affecting the performance of modern-day filtration and separation media. The most significant of these are membrane technology, nanotechnology, adsorption media, coalescing media, and composite and impregnated medium structures. It should be noted that the terms filter and filter medium have become generic for many forms of separation that are in addition to the simple concept of mechanical separation of contaminant particles by a porous medium.

Like any other industry, the Filtration and Separation Industry is buried in a massive bureaucracy of laws, regulation, environmental and safety matters, and quality management systems that makes operations exasperating and expensive. Although the new regulatory activity provides increased demand on the manufacture and performance of filter/separators and their media, the opportunities are vast. New and emerging technologies, such as nanotechnology, electric vehicles, electronics and computer development, advances in medicine and medical practice, all require new kinds of thinking in the development of filters and filter media and it well may be worth it.

The marketplace for filters and filter media are growing at a rapid pace. This is evidenced by the marketing statistics reports in Sections 1.1.2 and 1.1.3. These reports were provided by Brad Kalil, Director of Market Research and Statistics at INDA. Reported in Section 1.1.2 are excerpts from the “Worldwide Outlook for the Nonwovens Industry” published by INDA/EDANA in 2012 (1).

It indicates that the global consumption of nonwoven filter media was 465,000 tons in 2011 and is projected to grow to 744,000 tons in 2016. Although filtration media are projected to be only 8.7% of the total global nonwoven market in 2016, it is the fastest growing segment. From 2011 through 2016 the growth rate for nonwoven filter media are projected to be 9.8% per year. The largest market growth will be in Asia, which in 2016 is projected to consume 48% of all nonwoven filter media.

Section 1.1.3 is the filtration section of the “North American Nonwovens Industry, 2013–2018” report that will be published by INDA in 2015 (2) roughly at the same time this “Handbook of Nonwoven Filter Media” are being published. It indicated the filtration market will grow from $5.4 billion in 2013 to $19.1 billion in 2018, with a growth rate of 4.4% per year. In tons, the growth rate is projected to be 3.5% per year. The report a...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Preface
• Chapter 1. Introduction to Nonwoven Filter Media
• Chapter 2. Filtration Mechanisms and Theory
• Chapter 3. Properties of Nonwoven Filter Media
• Chapter 4. Raw Materials for Nonwoven Filter Media
• Chapter 5. Processes for Nonwoven Filter Media
• Chapter 6. Testing of Nonwoven Filter Media
• Chapter 7. Liquid Filter Applications
• Chapter 8. Air Filter Applications
• Chapter 9. Engine Filtration (Transportation)
• Chapter 10. Federal Law and Regulatory Activity That May Relate to Nonwoven Filter Media
• Chapter 11. Standards for Nonwoven Filter Media
• Glossary
• Nomenclature
• Bibliography
• Index