Using Composites for Custom Electrical Insulation

Safety, efficiency, and durability are crucial for custom electrical insulation. The insulated material keeps users safe by preventing direct contact with live electricity and minimizing electricity loss while protecting equipment against chemicals, dust, moisture, and other contaminants. Electrical infrastructure often requires insulation against shocks, fire, and short circulation to protect people and machinery. However, deciding on the best material for custom electrical insulation depends on the application, as not all insulating materials have the characteristics to handle certain conditions or environments.

Materials Used for Insulating Electrical Infrastructure 

Electrical infrastructure relies on insulating materials that ensure the efficiency and safety of these systems. Often, this will include integrating two or more materials to create a novel substance with different properties, essentially a type of custom electrical insulation. These composites will often serve their purpose better than homogenous materials, with each integrated material augmenting a composite’s properties.

Materials commonly used to insulate electrical infrastructure include: 

• Ceramics: With high dielectric and heat-resistant properties, ceramics don’t conduct electricity at all, making them ideal for high-voltage applications like power lines and circuit boards in laptops, smartphones, and tablets.
• Elastomers: Due to their flexibility and dielectric properties, elastomers like EPDM (ethylene propylene diene monomer) rubber, neoprene, and silicone make excellent insulating materials for cable jackets, connectors, gaskets, seals, wiring, and other components found in electronic equipment.
• Epoxy resin: Commonly used for transformers, switching equipment, printed circuit boards and bushings, and insulated coatings on cables and wiring, epoxies protect conductive components from short circuiting while also acting as a seal against moisture.
• Fiberglass: Offering good insulation and mechanical strength characteristics, it’s usually used as woven tubing made with glass fibers that wraps around cabling as “fiberglass sleeving.” These sleeves protect against abrasion, heat, and electricity, making them ideal for industrial applications like electrical enclosures and insulating paneling.
• Mica: With excellent dielectric strength and heat resistance, mica can be used as custom electrical insulation in high-heat conditions for capacitors, electrical coils, heating elements, motors, transformers, wiring, and other electrical components.
• Phenolic composites: With excellent dielectric qualities, phenolic composites are ideal for circuit boards, electrical panels, switching equipment and other electronic components where electrical isolation is necessary.
• Polyamides: Known more commonly as nylon, polyamides are decent and inexpensive insulators on their own, with high dielectric strength and good mechanical traits; when infused with glass fibers, these nylons work well in high-heat conditions for applications like cabling and wiring insulation, circuit breakers, connectors, electrical housings, and switching equipment.
• Polycarbonate: Transparent and highly resistant to impacts, polycarbonate is used to insulate circuit boards, electrical enclosures and protective covering for electronic components.
• Polyimide: Also known by the brand name Kapton, polyimide tape is made from polyimide film. Its chemical stability, flexibility, and heat resistance, combined with excellent dielectric properties, make it ideal for aerospace and electronic applications; applications include insulating circuit boards, wiring, and other electrical components in high-heat environments.
• PTFE (Polytetrafluoroethylene): Also known by the brand name Teflon, PTFE is used for insulating high-voltage wires and insulator components and for capacitor separation due to its resistance to heat and chemicals; often, PTFE comes as tubing, tapes, and sheeting that wrap around and insulate electrical conductors.
• PVC (Polyvinyl chloride): An economical and effective insulating material, PVC is often used for lower-voltage wiring and cable sheaths in residential households due to its resistance to abrasion, chemicals, and moisture. 

The electrical infrastructure’s prime purpose is to transmit and distribute electricity to the residential, industrial, and commercial spaces that require it. Electrical engineers must accustom themselves to the critical role these materials play in modern society. When composite materials are used, electrical insulation can often be better tailored to meet specific applications.

Why Use Composites for Custom Electrical Insulation 

Composites integrated into electrical infrastructure offer advantages over ceramics, glass, metals, or even polymers on their own. When combined with other characteristics like durability, heat resistance, and strength, the insulating properties of composites make them better than many traditional materials used for insulation. Custom electrical insulation that utilizes composite materials enhances the safety and performance of systems used to transmit and distribute electricity while also ensuring longer lifecycles for electrical equipment. The material properties composites offer make them ideal for custom electrical insulation.

Corrosion & Weather Resistance

While metals and their alloys are prone to corrosion or degradation due to sun ultraviolet (UV) radiation, composites resist these conditions far better. For this reason, composite insulation is often used for applications such as cable trays, cross arms for power lines, utility poles, or other applications that commonly expose materials to chemicals, damp conditions, or weather.

High Dielectric Strength 

Polymers reinforced with fiberglass and epoxy-based composites help prevent power loss and short circuiting in electrical equipment. With strong dielectric properties, these composite insulators help make high-voltage applications safer. For this reason, they’re often used for switching equipment, transformer components and transmission insulators.  

Lightweight Yet High Strength

With a higher strength-to-weight relationship, composites can maintain mechanical loads better than conventional materials. For this reason, composites used for custom electrical insulation often are integral to substations and other electrical infrastructure, as they’re generally more economical and easier to install.

Low Maintenance & Longer Lifespans

Because of their greater resistance to chemicals, wear and other environmental factors, composites need only minimal maintenance. This in turn extends the lifespan of electrical infrastructure while also ensuring a more dependable system.

Resistance to Fire & Heat

Composites used in electrical infrastructure often exhibit fire resistance and thermal stability. Additionally, some custom electrical insulation can even self-extinguish to provide extra protection in case of electrical equipment failure.

Composite Insulation Solutions for Electrical Infrastructure

Numerous insulators made from composite materials can be used to safeguard electrical infrastructure. Among these, composites that contain fiberglass have considerable potential as custom electrical insulation. These materials are already found in fuse cut-outs, electrical tools, substations, transformers, transmission lines for electricity, and other sensitive electrical infrastructure.

However, composites containing carbon fibers are more appropriate for other applications like conductor cores due to their exceptional mechanical traits. For custom electrical insulation, composite materials containing carbon fiber tolerate high-heat environments well because of their lower thermal expansion and higher stiffness-to-weight relationship. The use of carbon fiber in conductors enables greater distribution capacity, allowing them to handle higher electricity demand and increasing the conductor’s cross-section.

Continuous manufacturing processes like pultrusion are often used to produce custom electrical insulation. These processes are used for high-volume production of cross arms for power lines, conductor cores, conduits, insulator rods, and other electrical infrastructure. With pultrusion, custom electrical insulation is fabricated by pulling together resin-soaked strands of carbon or glass fibers, fabrics, mats, or other materials. These are then fed into a heated die where the composite cures, after which it’s cut to the required dimensions.

Another manufacturing method is pull-winding, a continuous process that’s used for fuse cutouts, utility poles, and other components. This method’s manufacturing throughputs can reach over ten times that of more traditional methods like filament winding for fabricating composites. Pull-winding allows more precise control over the orientation of fibers during composite fabrication, making it ideal for reinforcing the walls of composite tubing. This results in a lightweight product, leading to less waste when compared to processes like filament winding.

Custom Electrical Insulation from Spaulding Composites

Spaulding Composites Inc. manufactures advanced composite materials for custom electrical insulation. Our engineered thermoset composites are tailored to meet or exceed the needs of our customers globally. Additionally, our engineering team has considerable design knowledge that enables us to work with customers from development to product delivery. Spaulding offers the highest quality cottons and papers with reliable dielectric characteristics for producing composite insulators. We also work with resilient glass epoxies for utility tools, tube bodies, and similar applications, while bringing considerable experience with custom electrical insulation requiring a machine. To learn more about our capabilities for producing custom composite insulators for electrical infrastructure, contact the composite experts and Spaulding today.