You have plenty of choices in jacketing materials for cable assemblies. You need to see what features you need to pick and what to leave to make it suitable for your job. Sometimes, you may not get desired properties from a single material. In such cases, it is better to go for composite insulations. Two or more materials combine to suit a particular application in composite insulations. However, sometimes, a composite with desired properties may not be economically viable and commercially feasible. This blog will help you choose a proper one.
Table of Contents
- What are a Cable Jacket and its Purpose?
- What Jacket Properties and Characteristics do You Need?
- Types of jacket materials
- Cable Insulation vs. Jacketing
- Custom Wire & Cable Insulation & Jacket Materials
What are a Cable Jacket and its Purpose?
A cable comprises different layers to protect its inner components, and a cable’s outer covering or the first line of defense is the jacket. A cable jacket does not contribute to its electrical performance. It mainly protects the insulation and conductor from physical stresses, acts as a moisture barrier, and offers protection to the cable against flame and chemicals. Also, the jacket minimizes physical damage during and after installing a cable.
Caption: Tell cable jacket from wire insulation
What Jacket Properties and Characteristics do You Need?
Sometimes, manufacturers add certain fillers, inhibitors, activators, and plasticizers to enhance these properties. These properties make a cable suitable for different industrial applications.
Besides these properties, some other properties of the jacket make them easy to use and handle. For example, the cable jackets have specific colors. These colors allow easy identification, provide safety, and enhance appearance. Also, the jacket has elastic memory and a smooth outer surface texture. These features make it easy to handle and install, especially in coil cords.
Types of jacket materials
There are different types of cable jacketing materials used for industrial cables and cords, but you have to choose one compatible with your application. A cable jacket is either a thermoplastic or a thermoset material, and different types of materials belong to these two categories.
- Thermoplastic materials
Thermoplastic materials have a linear molecular structure, and thus, you can melt and remold them by heating. The common thermoplastic materials used for cable jackets are
PVC or Polyvinyl chloride
The PVC jackets do not have a broad range of thermal features. However, they are resistant to sunlight, heat, weather, abrasion, acids, and oils. The PVC jackets are innately flame-resistant, making them excellent for electronic wires. These jackets are suitable for street light cable systems, direct burial cables, and control cables with this high mechanical strength.
A PUR or Polyurethane jacket has outstanding ozone, oil, and oxidation resistance. They are long-lasting and perfect for use in retractile cables or cords. Sometimes, PUR jackets are specially formulated, making them excellent flame resistant.
This polyethylene polymer has chlorine in place of some hydrogen atoms. It is available in thermoplastic and thermoset versions. The thermoplastic version has excellent heat, flame, weather, oil, and oxidation resistance. In the thermoset version, it has cross-linking of molecules.
- Thermoset materials
Unlike thermoplastic materials, you can mold thermoset materials just once. If you continue to apply heat, these materials will burn. A thermoset polymer forms a cross-link with other molecules and comprises natural or synthetic rubber during the curing process. Due to these cross-links, you will often find the abbreviation XL before the name of these materials. The most commonly used thermoset materials for cable jackets are
Neoprene, synthetic rubber, and a rugged jacket. A cable with a neoprene jacket does not deform permanently when exposed to high heat, oxidation, aging, and sunlight. Thus, you can use these jackets for cables is highly rough environments. Examples are mine trailing cables and dredge cables.
It is also a synthetic rubber. This ethylene polymer is resistant to abrasion, oxidation, and heat. Also, it can survive in cold climates up to -60 degrees Celsius. If formulated correctly, it becomes flame retardant too.
Thermoset CPE is the cross-linked version of CPE. This polymer is suitable for cable jacket applications due to its excellent physical properties. This cross-linked polymer shows resistance against UV exposure, ozone, and prolonged water immersion. Also, it has high resistance to alkalis, acids, and solvents, suitable for the chemical processing industry.
Cable Insulation vs. Jacketing
Often, you use the terms insulation and jackets in the same spirit. Although both of these comprise the same materials, they have different meanings.
- Insulation is material in direct contact with the conductor, solid or stranded. On the other hand, a jacket is an outer layer protecting insulation and conductors.
- The purpose of insulation is electrical, i.e., to prevent electricity and heat loss. On the contrary, the jacket holds the cable together and provides excellent physical and chemical resistance to the cable.
- Makers generally use PVC (cheap, bonds well, and easy to strip), PP, PE, and polyurethane for insulation. For cable jackets, manufacturers typically use thermoset materials like rubber.
- When selecting jacketing material, manufacturers look to the environmental condition. When a cable is subject to harsh chemicals, moisture, heat, cold, and abrasion, it requires rugged material. As a result, makers pick the best thermoset and thermoplastic materials with high abrasion resistance. Also, the materials can withstand a wide temperature range (-67degree Celsius to 392 degrees Celsius). However, manufacturers look to the voltage, and current a cable will carry while choosing insulation materials. Not all insulation materials can bear high currents. For these, you need foamed materials like polyethylene. Sometimes, makers induce bubbles chemically in these materials, which allow the easy flow of high-speed signals.
Caption: ETFE jacket
Custom Wire & Cable Insulation & Jacket Materials
Selecting an insulating or jacketing material for a wire/cable is critical for its successful use in any application. Before picking any jacketing material, you need to consider factors such as temperature, fire resistance, UV resistance, flexibility, durability, chemical resistance, etc. The table below mentions some of the common jacketing materials with their characteristics.
The selection of correct insulation or jacket material is essential to use wires and cables for their intended application successfully. We are a leading manufacturer of ropes and cable harnesses. We can assist you if you are confused about many jackets’ material choices.