Fillers are generally used for three reasons:
- To fill gaps in a cable for a more attractive appearance.
- To create and maintain a sequence or lay-up of components.
- To add strength to a cable.
Types of Fillers
Solid Plastic. Typically PVC, and to a lesser degree, Polyethylene. These fillers are available in any size and are commonly used in the cores of many cables.
Paper. These fillers are used extensively in power cables (SJT, SVT, etc.). They are available in flame moisture resistant versions.
Foamed & Fibrillated Polypropylene. Used mainly for the ability to mold to the gap to be filled. These are the most commonly used cable fillers for computer based cable.
Cotton, Rayon. Cotton or rayon fillers are used as a good middle choice between solid and fibrillated polypropylene fillers due to their "filling" ability and low cost.
Kevlar. Used mainly as a strength member, Kevlar is very expensive and should be used when longitudinal strength is required. Kevlar is commonly used in Fiber Optics cables to improve impact and strain resistance.
Types of Binders
Tapes. Polyester and polypropylene tapes are commonly used to hold cable bundles together and are frequently used to provide isolation between conductors and shields.
Nylon & Textile. Nylon binders are mainly used when flexibility of a cable must be maintained. They are also used in telephone cables to separate bundles and are supplied color coded for that purpose. Textiles can be braided or served.