BOOK_CONTENT
From Handbook of Nonwoven Filter Media

4.2 Polymers

Polymers are used for the fibers in nonwoven webs and for the resins and additives used to bond, coat, and provide other properties to the fiber formed web.

In meltblown, spunbonded, and electrospinning processes the polymer is the fundamental raw material supplied to the process and the forming of filament fibers is an intermediate stage in the forming of the web. Web properties for these processes are determined by the appropriate choice of polymer based on its properties and selection of the process conditions for forming that polymer into a fibrous form.

On the other hand, formation of webs by the air laid, dry laid and wet laid processes begins with a raw material that is already in fiber form. These are shorter nonfilament types of fibers provided by some form of outside supplier. The choice of fiber properties is the guiding criterion in the design of the web.

Organic fibers and resin binders are composed of polymers. Their properties and processability are very much dependent on the chemistry and properties of the polymers from which they were made. A listing of the structures of many of the polymers used for nonwoven materials is tabulated in Table 4.1.

Table 4.1: Structures of polymers used in nonwovens

Polymer

Type(s) & trade name(s)

Chemical name

Application

Structure

Cellulose

Woodpulp

Vegetable

Fibers

  • ? Abaca

  • ? Manila hemp)

  • ? Hemp

  • ? Esparto Grass

  • ? Sisal

  • ? Jute

  • ? Kenaf

  • ? Flax

Cotton

Repeat unit:anhydro-beta-cellobiose

Copyright Elsevier Ltd. 2007 under license agreement with Books24x7

Products & Services
Specialty Fibers, Fabrics, and Textiles
Specialty fibers, fabrics and textiles are based upon a unique composition, weave, or technology, and are designed for specialized applications.
Natural Fibers and Fabrics
Natural fibers and fabrics consist of bulk fibers, yarns, or woven cloth manufactured from plant materials such as cotton, wool, linen (flax), sisal, jute, hemp, or silk.
Industrial Fabrics
Industrial fabrics consist of woven or non-woven cloth made from natural or synthetic materials.
Coated Fabrics
Coated fabrics consist of woven and non-woven cloth with a coating or resin applied to the surface or saturated into the bulk of the material to provide some additional property.

Topics of Interest

4.3 Fibers 4.3.1 Classification Fibers are classified by their source as follows: Natural fibers wood pulp, vegetable fibers, cotton, animal fibers (wool). Synthetic polymer fibers polyester,...

Fiber reinforced polymers (FRPs) are a relatively new category of composite materials that combine stiffness and strength with weight reduction and corrosion resistance. Known also as polymer matrix...

3.1 Characteristics and Properties of Air Laid Webs Air laid webs tend to be bulky structures designed for absorbency The major markets are diaper padding, feminine hygiene pads, incontinence pads,...

7.1 Introduction to Liquid Filter Applications Liquid filtration applications are concerned with the filtration of either aqueous or hydrocarbon fluids. A large use of liquid filter media made from...

Natural-fiber feedstock is an attractive alternative to glass fiber for reinforcing thermoplastic composites. Using natural fibers to reinforce thermoplastics produces composites that are low cost,...

Product Announcements
Mid-Mountain Materials, Inc.
Lydall Performance Materials
Mid-Mountain Materials, Inc.