Electrical tape was created by the 3M company in the 1940s. Though it can be made from a variety of plastics, vinyl is most commonly used in its production because it has a greater stretching ability than its counterparts. Consequently, electrical tape is more effective in maintaining good insulation for a long period of time. Electrical tape also must hold a certification that it not burn when overheated.
Reasons For Using Electrical Tape
Electrical tape has a twofold job to do. When wrapped around an electrical wire, its job is to stop electrical current passing to or from another wire by mistake, as this could create a short which could lead to the circuit breaker turning off and stopping electrical flow to the electrical device. Also, more dangerously, the short could start an electrical fire. Electrical tape's second purpose is to stop any possible electrocution if the wire happens to be live (hot) and is touched by someone.
Application of Electrical Tape
Electrical tape is applied to bare wire by rolling the tape both around and along the wire in a coillike fashion. No gaps should be present to ensure good insulation and to keep moisture or condensation from reaching the wire. While wrapping the tape, it should be slightly pulled at the same time so its elastic property is engaged. The tape's elasticity helps keep it tight and snug to the wire. However, if the tape is stretched too much, its ability to hold to the wire will be greatly diminished.
Color-Coded Electrical Tape
Black is the electrical tape color used most often, as it points to no particular color code. Black electrical tape is also impervious to ultraviolet radiation, which can damage other colored tapes. As a result, black tape is used on wires that will be in direct sunlight. Other colored tapes are used to indicate neutral wires (white or light gray tape), grounding wires (green or yellow/green striped tape), or wires at both ends of a long conduit for the sake of identification.
If wrapped several times around two or more objects, electrical tape is very strong and is hard to break. It also resists certain corrosive acids. It has a very long life before it loses its elasticity and needs to be replaced. Even though it is strong, most electrical tape can be torn off the roll by hand, though some permanent stretching around the break should be expected. Because of this, a knife or scissors cut is more desirable.
Due to its durable properties, people use electrical tape for reasons other than electrical insulation: bandages can temporarily be held in place by tape, drummers in bands tape their finger to help stop blisters, athletes use tape to stop shin guards from slipping, actors mark stage floors with tape to help them recall stage positions, and rugby players even pin back their ears to keep them being pulled by the opposition.