What is an Air Knife?
The Sonic XE Air Knife was the first extruded "tear drop" shaped air knife in the industry. Developed by Sonic in 1995, its modular design and infinitely adjustable gap have emerged as the standard design for industrial applications.
The term air knife is derived from a device called a doctor blade, a mechanical scraper used to control ink thickness in rotary printing presses beginning in the year 1900, and in most of today′s desk top printers. The doctor blade concept was later implemented in a few other industries to control the thickness of viscose solutions (oil, paint, water, etc) in the manufacturing of steel, textiles and paper but, it soon became obvious that mechanical scrapers for coating control in these other applications was not effective enough and required far too much maintenance, except in printing presses.
The ″air″ doctor blade was born in the 1940′s, which later became known as just ″air knife″, as the first non-contact method for coating control or complete solution removal when needed. High pressure compressed air was pumped into metal tubes having holes or slots thereby producing a thin curtain of high velocity air to uniformly remove excess coating from the base material as it passed by without any physical contact. Until the 1980′s, because air knives were only used in a few specialized textile and steel mill applications, the majority of all other industries had little knowledge of or any use for an air knife. The 1987 Montreal Protocol resulted in the worldwide elimination of hydrofluorocarbons in most industries so, the blower driven air knife was born.
Initially, blower driven air knives were round tubes with holes or slots just as it had been with compressed air. The poor efficiency of the round tubes was soon replaced when Sonic created the single piece extruded aluminum XE (eXtra Efficiency) air knife with a tear drop shape having a 0.95 coefficient of discharge (95% air efficiency). Today Sonic air knives are the standard for all air knife manufacturers and are available in six profile sizes from 1 - ½ to 10 ″ tall, lengths from 2 ″ to 144″ in assorted materials and with dozens of features and add-ons to suit different industries. Sonic Air Systems provides the air engineering to ensure that Sonic blowers and Sonic XE air knife combinations are both effective and with the highest energy efficiency.
By combining Sonic′s XE air knife technology with compact Sonic centrifugal blowers (3Hp to 50Hp), plus our comprehensive air engineering, Sonic provides our customers with air knife solutions. Sonic provides our customers with air knife solutions. Sonic is often copied but, our success is rarely imitated.