When some types of cables are made, filler materials are used as part of their construction. These materials are added for a variety of reasons, from increasing the cable’s life to providing protection from high temperatures. There are several types of fillers used in cable construction, and they have their own individual advantages and disadvantages.
Keep reading to find out why using filler materials is the best practice for cable construction and which materials you should use and avoid.
Table of Contents
What Is Cable Filler?
Simply defined, cable filler is the material inside multi-conductor cables that takes up extra space around the conductors to form the cable core into a certain shape. It’s most commonly used as a way to create a shape for the cable. Usually, cables are circular, allowing for maximum protection and flexibility, but manufacturers may also create other shapes.
While filler materials are essential for some cables, filler isn’t included in all types of cables. When manufacturing cable, it’s important to identify the purpose and function of the cable to evaluate whether filler is needed, and if it is, which material should be used. Before cable construction, manufacturers consider the following elements:
- Industry or application of the cable
- Filler type (if needed)
By working through specific focus points, it becomes clear which type of filler material — if any — is necessary for the cable type.
Reasons Why Some Cables Require Filler
There are different situations in which filler material is required for cables. It’s become increasingly standard for filler to be included in cables because of the materials’ effectiveness and the functional improvements they give to cable. Some cables need filler to do the following:
- Retain the shape of a cord: It’s common to see filler in cables for shaping and sizing. Many people like products that are aesthetically pleasing, and cable filler adds to the visual appearance of cords.
- Reduce friction: When a cable is already capable of conducting electricity, extra friction will increase the risk of electric shock. Luckily, cable fillers help reduce friction and, in turn, increase safety.
- Decrease heat: Many cable applications require the use of high or extreme heat. Therefore, filler needs to be included in certain cable designs for the purpose of protecting internal wiring from temperature damage.
- Protect from moisture: Sometimes, cables need to be protected from moisture exposure, whether from condensation or a sink. It’s obvious that electricity and liquid are a dangerous combination. For that reason, an essential aspect of cable construction ensuring the inside of the cable always stays dry.
- Increase flex life: No matter why you need to use cables, you want to ensure they last a long time. It’s not in anyone’s best interest for cables to split when flexed. With the help of cable filler material, cables can last much longer, resulting in better product performance.
9 Common Types of Filler Material Used in Cables
There are numerous types of cable filler material. Typically, cable filler falls into one of two categories depending on their intended environment — high-temperature fillers and low-temperature fillers. In other words, cables meant for use in extremely hot applications will have different filler material than other cables. From there, you’ll find cables with tape and other materials used as filler.
Here are nine of the most common filler materials you’ll find in different cable designs:
- Polyimide tape: This tape is made for high-temperature applications. It’s the perfect tape to protect against water damage and abrasion.
- Water-swelling tape: This tape is a filler that swells to the cable size to protect internal conductors in case of damage. It’s more expensive than other filler materials but can save money in the long run by protecting wires against water damage and shorts.
- PTFE tape: This tape is also effective in high friction and temperature applications. It’s very durable and capable of handling rugged, industrial applications.
- Foam: This filler material is versatile, perfect for filling in small spaces between wiring. It’s also easily moldable, which makes it great for keeping the shape of the cable.
- Cotton: Softer materials such as cotton are typically the cheapest filler options, and they can easily fill in space that harder materials like plastic can’t. While cotton shouldn’t be used for applications that require durability, you can find it in long strands of wiring.
- Paper: These fillers are typically twisted into round designs to fill space in high-voltage power cables. However, they can easily fail if exposed to heat or water, so they have to be treated for flame and moisture resistance. Additionally, paper filler breaks down more easily during motion and flexing.
- Plastic: This is a common material used for filler and is widely available in various sizes. The use of plastic as a cable filler is ideal for reducing crosstalk and other electrical interference. However, plastic as a filler tends to be more expensive and can greatly reduce cable flexibility. Within the plastic filler category, polyethylene is a standard filler material used for cable. It’s thermoplastic, making it moldable, lightweight and perfect for longer cables.
- Steel: This filler is best when the application requires high levels of strength. Steel can be “tied off” at the end of an assembly, which will transfer force away from the conductors.
- Kevlar®: Even stronger than steel is Kevlar®. It provides high strength for long cables and is commonly used to improve the performance of fiber optic cables. However, because of its durability, it can also come with a higher price tag.
These are just a few of the cable filler materials you may find in cable design.
Trust AerosUSA for High-Quality Cable Protection
Whether you have a flat or round cable or a cable with or without filler, you must ensure it’s protected so it can perform. AerosUSA offers cable protection and filler materials for every industry. AerosUSA’s versatile AIRflex plastic cable protectors are available for several applications and strengths. Or, if you need the most durable metal to protect your conductors, check out our protective metal conduits. No matter the application, our products will help keep your systems running even in extreme conditions.
Contact us at AerosUSA today to learn more about cable filler and protection options. Get a product that will last longer and perform for your needs.