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Wednesday, December 10, 2008

History of Waterjets

Dr. Norman Franz is regarded as the father of the waterjet. He was the first person who studied the use of ultrahigh-pressure (UHP) water as a cutting tool. The term UHP is defined as more than 30,000 pounds per square inch (psi). Dr. Franz, a forestry engineer, wanted to find new ways to slice thick trees into lumber. In the 1950's, Franz first dropped heavy weights onto columns of water, forcing that water through a tiny orifice. He obtained short bursts of very high pressures (often many times higher than are currently in use), and was able to cut wood and other materials. His later studies involved more continuous streams of water, but he found it difficult to obtain high pressures continually. Also, component life was measured in minutes, not weeks or months as it is today.

Waterjet cutting Machine
Dr. Franz never made a production lumber cutter. Ironically, today wood cutting is a very minor application for UHP technology. But Franz proved that a focused beam of water at very high velocity had enormous cutting power — a power that could be utilized in applications beyond Dr. Franz's wildest dreams.



In 1979, Dr. Mohamed Hashish working at Flow Research, began researching methods to increase the cutting power of the waterjet so it could cut metals, and other hard materials. Dr. Hashish, regarded as the father of the abrasive-waterjet, invented the process of adding abrasives to the plain waterjet. He used garnet abrasives, a material commonly used on sandpaper. With this method, the waterjet (containing abrasives) could cut virtually any material. In 1980, abrasive-waterjets were used for the first time to cut steel, glass, and concrete. In 1983, the world's first commercial abrasive waterjet cutting system was sold for cutting automotive glass. The first adopters of the technology were primarily in the aviation and space industries which found the waterjet a perfect tool for cutting high strength materials such as Inconel, stainless steel, and titanium as well as high strength light-weight composites such as carbon fiber composites used on military aircraft and now used on commercial airplanes. Since then, abrasive waterjets have been introduced into many other industries such as job-shop, stone, tile, glass, jet engine, construction, nuclear, and shipyard, to name a few.

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