4.1 Introduction

The raw materials for nonwoven filter media are divided into the following categories:

1. Polymers.

2. Fibers.

3. Binders.

4. Additives.

The choice of materials for the design of nonwoven filter media depends on performance, processability, and economics. The web must have the right combination of physical properties such as thickness, strength, flexibility, and tear resistance to be processed into its final filter form. It must have a raw material structure that optimizes its performance as a filter medium. Finally, the medium must be composed of materials that give it durability, chemical resistance, and environmental stability in its intended application.