subject: Modern Wire Wrapping Applications And Available Tools [print this page] Developed by Bell Laboratories in the 1950s, this technique involved wrapping a wire tightly around a terminal with two sharp edges (square cross-sectional area) which could form a consistent gas-tight electrical connection without soldering. With advancements in the electronic, telecommunication and aviation industries they also demanded more reliable and inexpensive means for solderless connections. Their problem was resolved perfectly by the technique now called Wire Wrapping. wire wrapping is now a common method to connect signal and power terminals in todays advanced industries.
It has been used in telephone exchanges, PCB Test Fixtures, Backplane Testers, control consoles, radios, radar, sonar, , and other complex pieces of equipment that are needed in small volumes.
Mechanical & Electrical Stability : Solderless wrapped connections have excellent mechanical and electrical stability due to their gas-tight contact area. They remain stable through exposure to severe temperature changes, humidity, corrosive atmospheres and vibration. The high shearing force of the wire at the corner of the terminal and high contact pressure remove surface contamination from the wire and the terminal, producing an intimate, clean oxidation free, metal-to-metal contact with large contact area. Initial pressure at the centre of the contact area may go as high as 100,000 psi. after the wrapping is complete cold flow causes pressure to drop to approx 30,000 psi at which point the metal stabilizes and the pressure remains constant. By bending the wire around the sharp corner of the terminal, the oxide layer on both wire and terminal is crushed or sheared, and a clean oxide-free, metal to metal contact is obtained.
Easy Removal: Although wire-wrapped connections are quick and permanent with superior mechanical and electrical qualities, they may be easily removed if necessary without damage to the terminal. To remove the connection, an unwrapping tool is placed over the terminal, engaging the first turn of the connection. Rotation of the tool removes the connection in seconds.
Types of Wraps: There are two types of wraps:
Standard Wrap Only the bare wire is wrapped around the terminal
Modified Wrap The first one and half to two turns (wraps) are made with the insulation wrapped around the terminal. These turns are in addition to the recommended turns (wraps) of bare wire. This wrapping process increases the ability of the connection to withstand vibration and reduced wire breakage.
For more information please log onto our site http://www.tycoproducts.co.uk and see the tools we can offer like Manual, Electric, Battery-Operated or Pneumatic wire wrap guns along with the wrapping bits and sleeves.
