Jacketing is a cable’s first line of defense. In the latest edition of Northwire’s eCURRENT newsletter, the authors explain that users should consider several parameters before selecting a jacket material for a cable.
A cable’s outer jacket is its primary means of protection against environmental and application demands. It is a crucial part of the cable and can be the determining factor for the longevity and durability of the cable or cable assembly. Choosing a jacket material can seem complicated, they explain, so users should by consider these questions regarding fundamental requirements.
What is the end application, its environment and does it require approvals?
The application is the number-one influencing factor when selecting materials for any component of the cable. Certain specifications or characteristics may be determined by the end use. For example, if the cable will be in a medical device, the jacket may need to be biocompatible and/or sterilizable, which will quickly narrow down the list of material options.
Material options will differ depending on the environment that the cable and end application will be exposed to—such as extreme temperatures or continuous flexing. Furthermore, time, temperature, and frequency of the exposure to the extreme environment will be important to know as well. And if the cable needs to be UL listed or have a CSA marking, select the materials depending on those requirements.
Will the connector be over-molded to the jacket?
It is important to consider both the over-mold material and the jacket material to ensure that they will adhere to each other. In addition to material consideration, shape is an important factor as well. If the cable assembly includes an over-mold, the cable must be round to ensure a clean shutoff and a pressured jacket is preferred over tubed.
Does the assembly process involve jacket stripping and if so, to what length?
When evaluating jacket materials, factor in any downstream processes such as stripping—including what tooling will be used—as some materials are easier to work with than others. For example, a polyurethane is more difficult to score and strip than a PVC. If the strip length is going to be considerable on the end of the cable, a tubed jacket will offer a quicker, easier strip.