Images credits: Find Tape; Rose Brand; Wikimedia
Cable and electrical tapes are a variety of pressure-adhering adhesive tape specifically designed to wrap, shield, mask, mark, or insulate types of electrical cables, wiring harnesses, electric components, or circuit boards. Electric tapes come in many colors and materials, but black, vinyl tape has become the consumer standard.
Cable and Electrical Tape Operation
Electrical tapes operate differently depending upon the materials of construction. Essentially, a type of adhesive is applied to a carrier or backing that provides electrical insulation. Some tapes may by self-adhering, meaning no tacky adhesive is used but the tape sticks to itself by the use of a high-friction carrier. Electrical tape owes its versatility to its good tensile strength, UV-resistance, lack of residue upon removal, and that it can be easily torn by hand.
For most jobs, diagonal, half-lapping of the tape is considered the optimal application method. This consists of overlaying each turn of the tape by half of its width, as represented below. The final turn should have reduced tension.
Image credit: 3M
Cable and Electrical Tape Production
Like other adhesive and industrial tapes, the manufacturing process involves large rolls of backing that are coated with an adhesive. After cooling, the tapes are cut into proper-width rolls and sent for distribution. Though the video below shows the manufacturing process for shipping tape, the methodology is identical.
Video credit: Science Channel via Youtube
Cable and electrical tapes are usually evaluated for professional quality and safety by standards organizations like Underwriters Laboratories (UL) or the Canadian Standards Association (CSA). Products approved by standards organizations are branded with the organization's mark and ensure a superior product.
Cable and Electrical Tape Configurations
Cable and electrical tape manufacturers can use whatever permutation of carrier and adhesive they desire for the marketplace they serve.
||PVC-backed electric tapes can be applied as a tape, film, or laminate. It has similar properties when compared to rubber, but is less expensive and more chemically resistant. When used for electrical insulation, the PVC must be plasticized to enhance its insulating properties. This is the most common electrical tape carrier.|
||Cloth materials like cotton can be used as the carrier material to improve tensile strength, heat resistance, and electrical resistance.|
||These are similar to cloth carriers, but are reinforced with glass or fiberglass particles to enhance heat resistance to over 300° F.|
||Acrylic films can be transparent and UV resistant. These are made of plastic resins. Polyimide films have moderate heat resistance, can be applied at low temperatures, and are relatively thin. They can also be used for wave solder masking.|
||Metal foils have aluminum, aluminum reinforced, or lead backings. These shielding tapes are meant for applications needing point-to-point electrical contact, grounding, and static charge draining.|
||Adhesive-coated polyolefin foams include an adhesive that is protected by a liner in the form of a tape, film or laminate. These compressible, electrical tapes offer good electrical conductivity with cushioning/recovery attributes. They can fill gaps and are ideal for metal or metal-plated surfaces.|
||Plastic products incorporate one or more plastic layers, or consist of plastic film or sheets that can be clear or colored, printed or plain, single-layered or multilayered, and combined with materials such as aluminum and paper. There are two general categories of plastics: thermoplastics and thermosets.|
||Rubber-backed cable tape provides excellent insulation for wires up to 600V. Many types will bond to itself to create a solid, water-tight mass. This includes synthetic rubbers.|
||Fluoropolymer films, layers or coatings consist of plastics such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF). Fluoropolymer coatings are used in applications that require superior chemical resistance, good dielectric properties, and water and stain repellent characteristics. Fluoropolymers are also used in applications where the material handled must not stick to the belt, fabric or laminate. Polytetrafluoroethylene (PTFE) is an insoluble compound that exhibits a high degree of chemical resistance and a low coefficient of friction.|
||Polyethylene teraphthalate (PET)/polyester products use a PET or polyester backing in the form of tape, film or laminate. This tape is puncture resistant, conformable, and has good electrical qualities.|
||Polyimide film maintains excellent physical, mechanical, chemical and electrical properties over a wide range of physical environments. Kapton® tape is made of polyimide film and a heat-resistant, silicone adhesive. Kapton is a registered trademark of DuPont Teijin Films. Polyimide films are very useful substrates for the manufacture of flexible circuit materials.|
||These tapes will use a solid, silicone backing in the form of a tape, film, or laminate. They provide tight, void-free and moisture resistant electric insulation. This is optimal for splicing and stress cones.|
||Acrylic adhesives provide excellent environmental resistance and faster setting times than other resin systems. Surfaces require no pretreatment and the adhesive has good sheer and peel strength.|
||Heat activated, thermally activating, or heat bond adhesives become tacky or sticky when heat is applied. The adhesive may soften but not necessarily melt. Hot melt adhesives can be repeatedly softened and melted by heat and hardened or set by cooling. Cooling allows the removal or repositioning of parts during assembly.|
||Non-adhesive tapes, films, or laminates do not have an applied adhesive. These tapes are self-adhering and rely on a high coefficient of friction to remain adhered.|
||Pressure sensitive adhesives (PSAs) or contact adhesives are aggressively and permanently tacky at room temperature in dry (solvent free) form. They adhere firmly to a variety of dissimilar surfaces upon contact, requiring only the application of finger or hand pressure. PSAs do not require water, solvent or heat activation in order to exert a strong adhesive force on materials such as paper, plastic, glass, wood, cement and metal. PSAs have a sufficiently cohesive holding and elastic nature so that despite their aggressive tackiness they can be manipulated by hand and removed from smooth surfaces without leaving a residue. This is the most common adhesive of electrical tapes and as such, is not usually specified on product packaging.|
||Rubber-based adhesives provide highly flexible bonds and are usually based on butadiene-styrene, butyl, polyisobutylene or nitrile compounds.|
||Silicone adhesives and sealants have a high degree of flexibility and very high temperature resistance (600°F). While available as a pressure sensitive application, some silicone adhesives may require ventilation, UV or EB radiation to cure.|
Tape Colors and Patterns
Images credits: Find Tape; Suck UK
Due to the ease of manufacture and versatility for electrical tape, manufacturers may elect to produce tapes in color series or patterns. This type of electrical tape is called phasing tape. Other types may have spaces for marking letters or numbers. This will help users determine adjacent cables that supply separate sources, or for an aesthetic appeal. Common colors and designs include blue, brown, green, grey, orange, red, purple, rainbow, striped, poke-a-dot, and camouflage.
The following chart provides a common--but not universal--means of marking lines by color:
Table credit: Wikimedia
Cable and Electric Tape Specifications
There are only two important geometrical aspects to consider, width and thickness. Length is unimportant because this is determined by the user at the point of application.
Width is the measurement across predetermined edges of the tape. Tapes can be cut by the customer to smaller widths.
Thickness is the distance between the two, flattened surfaces of the tape (carrier and adhesive). It is usually expressed in mils or thousandths of an inch and is measured under pressure with a gauge.
The following performance attributes are common in certain tape configurations.
Cable or electrical tapes may feature increased thicknesses or proprietary properties to prevent damage to the wires.
Anti-static tapes or ESD control tapes consist of conductive, foil or metallized backings and are used in applications requiring control static charges or electrostatic dissipation (ESD).
Dielectric tape or electrically insulating tapes are used for marking, splicing and wrapping electrical power cable, power distribution wiring, and electrical connections. Dielectric tape aids in the prevention of shorting between phases or between the hot, common, neutral and ground wires in electrical wiring. Dielectric tapes typically have a voltage rating.
Electrically conductive products can conduct electricity and provide protection from electrostatic discharge (ESD). They may also provide shielding from electromagnetic interference (EMI) or radio frequency interference (RFI). Conductive tapes and films are used in electrical heating elements and other electronics applications.
Shielding tape consists of adhesive tape with a metal foil or metallized film backing. The shielding tape is wrapped around splices where shielding was removed or on sections of signal, video or electronic data cable with damaged shielding. EMI or RFI shielding tape may also be used around component or electronic devices. The metal layer provides shielding against noise generated by electromagnetic interference (EMI) or radio frequency interference (RFI).
Once applied, some tapes may become permanently bonded to the substrate. Tapes that are designed to be removable generally do not damage equipment, but may leave adhesive residue. Removable tapes are typically meant for one-time use.
Cable and electrical tapes particularly are used to form a protective layer on the wire or cable, and to provide protection against wear, corrosion, dust, water, electrical discharges, oil or grease, and other environmental conditions.
Safety film and tape products are used for flagging or as barricade tape. Reflective tapes are often used in safety applications. Multi-colored tapes can be used to differentiate similar wires.
Thermally insulating tapes provide electrical wire with insulation from heat. This is ideal for wiring near engines or furnaces.
Transparent products allow the transmission of light. A tape is rated as transparent if 10-point type can be read easily when the tape is applied directly over it.
Weather resistant tapes are suitable for outdoor use and resistant to ultraviolet (UV) light, cold, heat, water or other weather conditions. Common vinyl cable tapes provide quality UV resistance.
Cable and Electrical Tape Applications
Cable and electrical tapes are most commonly found on electrical wires and devices to enclose, insulate, or mark components. It can also be used to adhere mechanisms and heat sinks to circuit boards. Electrical tape is excellent for masking electronic devices during plating, soldering, cleaning, or etching. It can be used to assemble solar cell module parts and also for temporary wafer bonding. Integrated circuit packaging may utilize cable tapes, as might the inner wraps on motor and transformer windings and the overwrap on motor rewinds.
Electrical tape is commonly used as a stand-in for duct tape because of its similar properties.
Images credits: Topdown MX5 ; Vagabond Journey; Winslomb