Popular cable types/materials in descending order of upper temperature rating
MICC Instrumentation Cables
MI Cable is manufactured from completely inorganic materials. Available in Pure Nickel (Nickel 200) or 27% Nickel Clad Copper conductors. The metallic sheath materials for instrumentation range from Stainless steel (least expensive) to Inconel, Nickel 200, alloy 825 and many others. The insulation is a compressed magnesium oxide powder. Applications include thermocouple pairs (common calibrations include J, K, T, E, etc.), and critical instrumentation circuits where extreme high temperature wire has to be replaced regularly or cable is expected to survive and provide circuit integrity in a fire situation. By their nature, MI cables tend to be inflexible and require to be "dressed" into position as one would a copper water pipe.
Nextel (Ceramic Braid) thermocouple wire
Nextel 312, is an Alumina-Borica-Silica fibre, which is braided directly onto thermocouple alloy; this insulation retains strength and flexibility at a continuous exposure to 1200°C, and short term exposure to 1425°C (2600°F). Most common metals (except molten tin and copper) do not attack the fibres. Furthermore, due to the fact that Nextel 312 Ceramic fibres contain no residual acids or chlorides, corroding and etching is eliminated. This particular product will outgas on first heat up. The first firing should be in air to oxidize out the sizing and lubricants etc. used to hold the yarn together and facilitate the spooling and braiding process. Once fired to the "use" temperature, it should be OK for vacuum or protection tubes; although, it is not recommended for use in abrasive environments, without the protection of Nickel or Inconel® overbraid.
Vitreous Silica Fibre Thermocouple Cables
Vitreous Aluminosilicate fibres are a family of high temperature fibres, designed to be used in a variety of industrial and commercial applications. Manufactured from alumina-silica materials, these fibres offer such characteristics as high temperature stability, low thermal conductivity, low heat storage, excellent thermal shock resistance, light weight, and superior corrosion resistance. Not recommended for abrasive applications at high temperatures without stainless steel, Nickel or Inconel® overbraid.
Fibreglass Insulated and Served thermocouple
Fibreglass insulated thermocouple wire, is low cost, high temperature wire. The glass braid serves as a flexible insulator for the thermocouple conductors, which are then impregnated with a heat and moisture resisting finish, thereby promoting fibre bonding, reducing fraying and providing ANSI coding specifications for pigmentation and calibration.
Glass Served Fibreglass Jacketed thermocouple
Glass served/Fibreglass Jacket thermocouple wire is low cost, high temperature wire. The glass serving is an excellent insulator and is augmented with an overall fibreglass braid that is treated with a high temperature, moisture resisting finish. The glass serving allows more insulation to be used on the alloys when opposed to a glass braid dielectric. The entire assembly can be colour coded per ANSI specifications.
Mica / Glass Composites (MGT, MGS, MGR and Instrumentation/Control Multiconductor cables)
Mica is applied as a tape, providing the primary insulation and first line of defense against deterioration of critical circuits. Additionally, an overall glass braid is applied over the mica tape, to hold it in place, and to provide conductor coloration. Much used as low voltage and instrumentation cables requiring specified Fire Resistance for the safe shutdown of process plant and equipment. "Lead wire" versions are unaffected by flame, fuels, solvents, most acids, alkalis and oils. Popular for the wiring of ovens and other high temperature equipment. "Flexing" oil resistant versions available for applications where cables will continuously move at high temperatures. Cleanstrip and non-fraying, anti-itch lead wire versions available for high-speed automated cut and strip machines.
300 or 600 Volt grade multicore/pair Instrumentation/Control cables available.
Sintered Kapton® Dupont / Polyimide Tape
Kapton® is a tough polyimide film, exhibiting an excellent balance of physical, chemical, and electrical properties, over a wide temperature range, with superior dimensional stability at elevated temperatures. It is a very thin insulating material, allowing wire to be installed where space and weight are at a premium in applications like airframe and satellites. Non-flammable and radiation resistant and mainly used as bunched single cores.
PTFE is the original cablemaking fluoropolymer. It provides outstanding mechanical, electro-chemical (inert to nearly all industrial chemicals and solvents), temperature and friction resisting characteristics. Furthermore, PTFE is a thermoset material, which will not melt or flow; this unfortunately also means that cable insulations are normally applied in an expensive taping operation and require "sintering" to seal the tape edges after application or in non-continuous presses, which prevent the production of long reel lengths. Due to its outstanding dielectric properties less insulation is required in comparison to most other insulations (except Kapton®); typically about .005" for 30 AWG-18 AWG, permitting cable with a smaller overall diameter, to be used where space or the lack of space, is essential. Temperature ranges of this particular wire range from -70°C to +260°C. UL/CSA certified lead wire.
Extruded Teflon PFA® Dupont
Teflon® PFA, is a high-performance, melt extrudable, fluoropolymer resin, developed to extend the range of uses of PTFE fluorocarbons, by providing an easily extruded thermoplastic, with outstanding properties. PFA is especially useful to designers and end-users, who require a thermoplastic with excellent chemical stability, outstanding electrical properties, and mechanical strength for use in non-stick, thin-wall, high and low temperature environments from -70°C to +260°C. Teflon single lead wires (600 and 300 Volt). Shielded or unshielded, multiconductor/pair/triad sensor and instrumentation cables with silicone sheaths for added flexibility also available.
Extruded Tefzel FEP® Dupont
FEP Teflon® is a high-performance fluoropolymer resin and was developed to extend the range of uses of the Teflon family by providing an easily extruded thermoplastic with outstanding properties. FEP is especially useful to designers and end-users who require a thermoplastic with excellent chemical stability, electrical properties, and mechanical strength for use in high and low temperature environments -70ºC to 200ºC. Less expensive than PFA whilst retaining most of the same characteristics. Much used in lead wires or as shielded or unshielded, multiconductor/pair/triad sensor and instrumentation cables with silicone sheaths for added flexibility. Generally built in sizes from 26 AWG to 4 AWG.
Fluorosilicones cope well with temperature extremes and a wide range of chemicals. Fluorosilicone has a high resistance to flame, weather, oxidation, ozone; plus a better resistance to silicate hydraulic fluids, alkalis, alcohol and synthetic lubricants than ordinary silicone compounds. Generally used in enclosed applications where not subjected to extreme vibration or mechanical abrasion. Good for temperatures as low as -150° C . Applications for hielded or unshielded, multiconductor/pair/triad sensor and instrumentation cables include lighting, rotating machines, plastics machinery, etc.
Extruded Tefzel ETFE® Dupont
Tefzel® insulated and jacketed cables offer a wide service temperature. Tefzel® insulated cables cost less than conventional PTFE/PFA insulated cables. Tefzel® ETFE meets the need for outstanding dielectric and mechanical properties for lightweight insulation in satellite cabling. Tefzel® retains high levels of strength, toughness and dielectric properties upon long-term exposure to radiation in the space environment.
Silicone Rubber, Glass Braided
UL Recognized for use in electronic ignition or similar application in gas ranges or gas or fuel oil burner systems where protected from damage during handling, installation and servicing of the appliance. Silicone rubber is a very flexible, easily to terminate, relatively low cost, high temperature insulating material -80°C to +200°C (with glass overbraid) insulation. The silicone rubber compound is typically augmented with a braid for added abrasion resistance and increased flammability characteristics. Typical insulation thicknesses range from .020" to .045". Silicone rubber compounds are available which provide flame resistant insulation capable of passing Underwriters Laboratories vertical flame test VW-1, and the Mil-W-16878 specifications for flammability. Furthermore, silicone rubber compounds are fungus resistant, resistant to weathering, and because they are extremely stable and contains no sulphur, chlorine or other acid producing chemicals, do not not cause staining, corrosion or deterioration to other materials with which they come in contact ~ and have outstanding electrical characteristics.
Thermoplastic elastomers (TPE), sometimes referred to as thermoplastic rubbers, are a class of copolymer i.e. a physical mix of polymers (usually a plastic and a rubber). TPEs have outstanding flexibility and mechanical strength up to their continuous use temperature of 150°C, whilst a flexible choice of processing options (tube extrusion and pressure die coating) makes TPE a popular the choice for wire and cable applications. It has high temperature resistance: 3000 hrs at 160 °C for TPE U (peak temp up to 200°C) yet also exhibits excellent low temperature ductility and impact strength. Good copper stability (both TPE-E and U).
E and P grades provide extra fatigue resistance, good chemical and abrasion resistance and are popular for robotics and machine applications.
Polyethylene is one of the most widely used polymers for cable insulation and jacketing. Its excellent properties make it useful in many telecom and power applications. During the compounding process, additives can be introduced to improve resistance to ageing and to UV light, or to produce cellular insulation, thus improving the dielectric properties needed for some telecom applications. Polyethylene can also be cross-linked to improve its thermo-mechanical and water resistance for power applications. Cross-linking changes polyethylene from a thermoplastic to a thermoset material, which creates a high resistance to stress cracking, cut-through, soldering, and many solvents. Polyethylene is a very flammable material that can be controlled by the use of special flame-retardant additives. These additives, however adversely affect many of polyethylene's electrical properties, such as the dielectric constant, power factor, and dielectric strength. Low cost, chemically cross-linked polyethylene insulation, can be used for internal wiring of appliances. It is available in all colour, stripes, hash marks etc. UL listed fixture wire 18 AWG - 14 AWG.
DuPont™ Hytrel® thermoplastic polyester elastomer can meet multiple requirements. These include flex-fatigue resistance, flexibility at low temperatures, resistance to chemicals, to UV exposure and to impact; it is also a good electrical insulator, and has good processing characteristics that permit cost-effective manufacturing of thin wall extrusions for use in robotic applications. TPE materials have the potential to be recycled because they can be extruded and reused like plastics, but they have typical elastic properties of rubbers which are not recyclable owing to their thermosetting characteristics
High Temperature PVC
Because of its wide range of properties, PVC is typically used either as a dielectric or sheathing or both in applications such as: power distribution cables, building wiring, appliances wiring, flexible cords, high temperature wiring, industrial wiring, coaxial cables. The maximum temperature range for the best PVC formulations is -55°C to 105°C with general purpose vinyls ranging -20°C to 80°C. PVC has excellent flame, moisture and abrasion resistance, as well as, alcohol, ozone, acids and solvent resistance. High temperature PVC (Polyvinyl Chloride) is an inexpensive thermoplastic material typically used in the process industries for thermocouple extension cables that are used outside the heat source area.
Polyurethane sheathed cables can be very flexible, have outstanding electrical performance, ageing characteristics, resistance to oils, and survive mechanical abuse. Polyurethane cables are popular for their wide ambient temperature range (-25°C to +80/110°C); UV, oil and water resistance; enhanced memory in curly cords, good abrasion resistance, retractability and strength.
Polypropylene brings attributes needed for many wire and cable applications, including high service temperature with good mechanical and electrical properties but is considerable harder and stiffer than polyethylene. It also has relatively poor low-temperature flexibility. Polypropylene has properties almost identical to that of polyethylene and is used almost exclusively for thin wall primary insulations. Polypropylene can be rated for -30°C to 80°C. Polypropylene can be foamed for improved electrical properties.
Polyethylene is the compound most widely used in coaxial and low capacitance cables due to its excellent electrical properties. All of the polyethylenes are excellent dielectrics. Outstanding electrical properties include high insulation resistance, high dielectric strength, low dielectric constant, and low dielectric loss at all frequencies, excellent resistance to cold flow, and good abrasion resistance. Although polyethylene is flammable, additives can be used to make the polyethylene flame retardant at the expense of the dielectric constant and power loss characteristics. Usable temperature ranges from a low of -65°C to as high as 80°C. Polyethylene (in high, medium and low densities) is generally very hard and stiff, and these properties typically do not change over the usable temperature range. Polyethylene can be used by for primary insulation as will as the cable jacketing compound so is widely used for insulation on telephone signal and control cables, high frequency electronic cables, high and low voltage power cables.
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