Glass-coating is a process invented in 1924 by G. F. Taylor and converted into production machine by Ulitovski for producing fine glass-coated metal filaments only a few micrometres in diameter.
In this process, known as the "Taylor-wire" or "microwire process" or "Taylor-Ulitovski process", the metal to be produced in microwire form is held in a glass tube, typically a borosilicate composition, which is closed at one end. This end of the tube is then heated in order to soften the glass to a temperature at which the metal part is in liquid state and the glass can be drawn down to produce a fine glass capillary containing a metal core. In recent years the process was converted to continuous one by continuously feeding the metal drop with new material.
Metal cores in the range 1 to 120 micrometres with a glass coating a few micrometres in diameter can be readily produced by this method. Glass-coated microwires successfully produced by this method include copper, silver, gold, iron, platinum, and various alloy compositions. It has even proved possible to produce amorphous metal ("glassy metal") cores because the cooling rate achievable by this process can be of the order of 1,000,000 kelvins per second.
Applications for microwire include miniature electrical components based on copper-cored microwire. Amorphous metal cores with special magnetic properties can even be employed in such articles as security tags and related devices. Cobalt and iron base alloys are used to produce antishoplifting labels and security papers.
The Taylor-Ulitovsky process has been proven successful in academic environments however it was never duplicated for high volume mass production. The modified Adar-Bolotinsky process has made it possible to produce micro bonding wire directly from the melt, by casting instead of the traditional drawing and take this capability to mass production. This special manufacturing process also makes it possible to develop RED micro wire, for example RED Copper wire which is unique composite wire with a thin glass coating and a soft copper core.