One of the factors which can affect the price of wire and industrial cable is the insulation. In the wire world, there are always new innovations and different types of alternatives, each contributing to a specific role for different wire products. One of the most important parts of electrical products today is the type of insulation, also known as electrical insulators. Before delving into insulating materials of various chemical formulations, let us first review the purpose of electrical insulation. As the name suggests, it is an insulator, meaning it keeps things (electricity) inside. Wikipedia defines it as "a material through which an internal charge cannot flow freely or with little current under the influence of an electric field (Wikipedia)." There are quite a few wire insulation materials, ranging from nearly identical connections to completely different connections. Many similar structures are basically the same, but some manufacturers slightly change some of the features of the structure because it allows them to trademark the material. This makes it increasingly difficult to cover a large number of very similar compounds. 
Therefore, the most effective way to destroy these insulations is to use their basic and most popular composite structures. A cable is a group of one or more wires twisted together, insulated by a material and responsible for transmitting electricity. Cables are used for wiring inside buildings, buried in the ground, etc. Flexible power cords are used in portable devices. Today, there are different types of cables with different materials and sizes depending on the purpose. Power cables are very important in electrical installations. Today, the bold role of the cable can be seen in all walks of life. A large part of the energy transfer in the electricity industry takes place through cables. The importance of cables is so great that every day a new type of cable is introduced to the world. What are the components of the cable? In general, the components of a cable are conductors and insulators. The cable conductor is the main component of the cable and is a metal made of copper or aluminum in the form of wire, single strand, twisted, round and triangular. There are different types of managers; among them: single wire conductor, ordinary twisted circle, and ordinary twisted circle compact, flexible ordinary twisted sector compact. Conductor selection is based on usage, standard recommendations, and even consumer taste. They are suitable for fixed installations, single stranded and multi stranded conductors, for flexible applications, and highly flexible conductors. 
Types of wire insulation
Insulation of wire is a critical outer layer applied to different types of wires and cables to protect the wires from external conditions. The insulation or jacket also prevents current from leaking from the wire into the surrounding area. To meet the needs of a variety of wire materials, setups and applications, wire insulation is available in a variety of types and materials. Common materials for wire insulation Depending on the application, wire insulation can be composed of many different materials, including plastic, rubber, and fluoropolymers. Plastic Plastics have many useful properties that are ideal for wire insulation, including ductility, electrical resistance, UV resistance, and fire resistance. The following are popular plastic materials for wire insulation: Polyvinyl Chloride (PVC): PVC is one of the most commonly used insulation materials due to its cost-effectiveness and high durability. It is highly fire and chemical resistant and retains its shape and durability in temperatures from -55°C to 105°C. Semi-rigid PVC (SR-PVC): SR-PVC can withstand abrasion and has a high resistance to acids, bases, water, and heat. Plenum Polyvinyl Chloride (Plenum PVC): Plenum PVC is designed to be more fire resistant for use in fire retardant spaces. Polyethylene (PE): PE is denser and harder than PVC. It is highly electrically insulating and particularly resistant to cracking at temperatures of -65°C and 80°C. Polypropylene (PP): Polypropylene has a higher temperature resistance than PE, with an operating temperature of between 30°C and 80°C. Polyurethane (PUR): PUR is flexible and has high water, chemical, and abrasion resistance. It offers excellent performance in marine applications and low temperatures from -62°C to 93°C. 
Chlorinated Polyethylene (CPE): CPE is a cost-effective insulation material with excellent resistance to oil, heat, and outdoor conditions. Nylon: Often used as a secondary insulator for softer insulation materials. Nylon provides a soft layer of protection but is less water resistant. Rubber Rubber materials are more flexible than plastic, especially at lower temperatures. Rubber materials used for wire insulation include: Thermoplastic rubber (TPR): TPR is resistant to a wide range of temperatures, UV radiation and abrasion. Neoprene (polyneoprene): Neoprene has excellent abrasion and cut resistance, as well as oil and solvent resistance. Styrene Butadiene Rubber (SBR): SBR has higher temperature resistance than neoprene and is typically used in MIL cables with temperatures from -55°C to 85°C. Silicones: Silicones are valued for their high flexibility, excellent flame retardant properties, and heat resistance up to 180°C. Fiberglass: Fiberglass is used for very high-temperature applications up to 482°C. It is also resistant to chemicals and water. Ethylene Propylene Rubber (EPR): EPR is highly resistant to heat, oxidation, water, acid, alkali, alcohol, and electric current. Chlorosulfonated Polyethylene (CSPE): Ideal for low-pressure applications, CSPE has good chemical and UV resistance and operates over a wide temperature range. Ethylene Propylene Diene Monomer (EPDM): EPDM has low conductivity, is extremely flexible, and can operate at temperatures from -45°C to 177°C. 
Types of cable insulation
Cable and wire both need an insulation which can be covered by two types of insulation. Insulating materials commonly used to cover copper wire (and other) electrical conductors fall into two broad categories: thermoplastics and thermosets. What is the difference? If we take a look at our Roman Wire and Cable Basics Handbook (yes, it is a long time ago, but yes, it is still fully applicable), we have the following description: Thermoplastic: This material softens or even melts when exposed to high enough temperatures. In other words, once the material is put together, it becomes relatively hard but flexible, like most plastics we encounter in our daily lives. However, if it is exposed to heat sometime in the future, it will soften and melt. The main reason for choosing thermoplastic is that it is the most economical type of insulation. Some common thermoplastic insulation materials in use today:
- PVC (polyvinyl chloride)
- PE (Polyethylene)
- ECTFE
- Polyvinylidene fluoride
- nylon
Thermoset materials: On the other hand, this material does not soften at high temperatures. When mixed and cured, it becomes "rubber" and retains its properties even when exposed to high temperatures... Thermoset insulation is often used where wires or cables are exposed to high temperatures. 
Some commonly use Thermoset insulation materials are:
- XLPE
- CPE
- EHR
Thermoplastic compound Thermoplastic compounds use additives to improve specific properties of thermoplastics. Depending on the project you are working on, you may want to choose wire insulation that specifically uses one of the following thermoplastic compounds to better suit your needs. Polyvinyl chloride PVC, sometimes called vinyl or polyvinyl chloride consists of three types of vinyl compounds - standard, semi-rigid, and irradiated. Depending on the recipe, the temperature rating can vary from -55C to 105C. Typical dielectric constant values can range from 2.7 to 6.5 Standard PVC, rated 1000 volts or less, for connection, computer, and control wiring. Various compounds are used in 60C, 80C, 90C, and 105C service as well as commercial and military applications. Semi-rigid PVC (SRPVC) is harder than standard vinyl. It has higher wear and penetration resistance and provides more stable electrical performance. Irradiated PVC has improved resistance to abrasion, cutting, welding, and solvents. Irradiation changes vinyl from thermoplastic to Thermoset. Polyethylene (PE) is a very good insulating material due to its low dielectric constant, stable dielectric constant over all frequencies, and very high insulation resistance. In terms of flexibility, polyethylene can range from rigid to very rigid, depending on molecular weight and density. The low density is the most flexible, while high density, high molecular weight formulations are very rigid. Moisture resistance is very good, however, both types are flammable. Brown and black formulas have excellent weather resistance. Solid insulation has a dielectric constant of 2.3 and cellular (foam) designs have a dielectric constant of 1.5. RULAN is a flame retardant polyethylene-containing additives that inhibit the rate of combustion. These additives have little effect on the physical or electrical properties of the insulation. 
The electrical properties of propylene (solid and honeycomb) are similar to polyethylene. This material is mainly used as an insulating material. In general, it is harder than polyethylene, so it is suitable for thin-walled insulation. UL's maximum temperature rating can be 60C or 105C. Solids have a dielectric constant of 2.59 and cellular (foam) designs have a dielectric constant of 1.55. KYNAR has excellent mechanical strength, excellent wear and penetration resistance, and significantly reduced cold flow, making it an excellent backplane wire insulation. Kynar is self-extinguishing, radiation resistant, and rated to 135C. Rated at 150C, TEFZEL (ETFE) has very good electrical properties, chemical inertness, high flex life and excellent impact strength. Tefzel can withstand unusual physical abuse and is self-extinguishing. HALAR (ECTFE) has a unique gravity rate of 1.68, the lowest of all fluorocarbons. Halar charcoal but does not melt or burn in direct contact with the flame and extinguishes as soon as the flame is removed. Its other electrical, mechanical, thermal and chemical properties are almost identical to Tefzel. It can withstand a temperature rate between -70C to 150C. TEFLON (FEP) can be extruded in the same way as PVC and polyethylene, allowing longer wire and cable lengths. FEP has excellent electrical properties, chemical inertness and an operating temperature of 200C. Teflon is a registered trademark of DuPont. TEFLON (TFE) can be extruded in a piston type hydraulic process. The length is limited due to the amount of material in the piston, the thickness of the insulating layer and the size of the preform. TFE must be extruded on silver or nickel-plated wire, rated at 260C and 200C respectively. Teflon is a registered trademark of DuPont. Like other products, PFA has excellent electrical properties, high operating temperature (250 C), resistance to almost all chemicals, and flame retardancy. Thermoplastic rubber (TPR) has similar properties to vulcanized (Thermoset) rubber. The advantage is that it is treated as a thermoplastic, it is extruded onto the conductor. Like many traditional rubber materials, TPR is highly resistant to oils, chemicals, ozone, and other environmental factors. It has low water absorption and excellent electrical properties and is very flexible with good wear resistance. 
Thermoset compounds Thermoset compounds are often used in applications involving higher temperatures because they do not melt when heated. They also keep their shape better in cooler environments. The commonly used Thermoset types include: Chlorosulfonated polyethylene (CSPE) is sometimes used as insulation for motor cables rated at 105C but is most commonly used as a jacket compound. CSPE has excellent tear and impact strength, excellent abrasion resistance, ozone resistance, oil and chemical resistance, and good weather resistance. This material also has low moisture absorption, excellent flame and heat resistance and good dielectric properties. SILICONE is a soft insulating material with a typical temperature range of -80C to 250C. It has excellent electrical properties as well as ozone resistance, low moisture absorption, weather resistance and radiation resistance. Silicones generally have low mechanical strength and poor wear resistance. While silicone rubber burns slowly, it forms a non-conductive ash that can in some cases preserve circuit integrity. Ethylene propylene rubber (EPR) is a chemically cross-linked Thermoset high temperature rubber insulation. It has excellent electrical properties as well as excellent thermal stability and flexibility. EPR has good compression, cutting, impact, tearing and wear resistance and is not attacked by acids, bases and many organic solvents. It is also very moisture resistant. EPR is classified up to 150C. Cross-linked polyethylene (XLP) is a material that is more resistant to environmental impact, cracking, penetration, ozone, solvents and welding than low-density or high-density polyethylene. Sometimes referred to as XLPE. Chemical cross-linking or radiation cross-linking is possible. 
Semi-butyl rubber (SBR) is flexible and offers good heat and moisture resistance at an economical price. It must be coated for mechanical and chemical protection. SBR is for a maximum temperature rating of 75C. There are many different factors when choosing wire and cable, including the type of wire insulation. Read on to learn more below, or search our catalog to find the right wire for your next product or project.