Fillers, Binders & Identification Methods

Fillers are generally used for three reasons:

  1. To fill gaps in a cable for a more attractive appearance.
  2. To create and maintain a sequence or lay-up of components.
  3. To add strength to a cable.

Types of Fillers

Solid Plastic

Typically TVC, and to a lesser degree, Polyethylene. These fillers are available in any size and are commonly used in the cores of many cables.


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.


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


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.

Cable Identification Methods

ID Threads

Each manufacturing company has identification threads which can be run inside the cable should the need arise to identify the manufacturer.

Printed ID Types

ID tapes with a manufacturer’s legend printed with appropriate UL and CSA information can be run in the cable.

Surface Marking

a) Indent Print – Physical impressions of appropriate information in the cable jacket.

b) Surface Ink – Inked information on the jacket surface.

c) Embossed Legend – Raised lettering on the cable jacket.

d) Sequential Printing – Printing occurs every foot in ascending numerical order.