Waterjet technology changed drastically in the 1980s. Up until then, waterjet machines had mostly been used to cut soft goods. But in 1980, Dr. Mohamed Hashish, now senior vice president of technology at Flow International Corp., Kent, Wash., discovered that adding abrasives to the water stream allowed the machines to cut harder materials, changing the waterjet industry forever.

Curiosity leads to invention
While studying for his Ph.D. in fluid mechanics at Concordia University in Montreal, Hashish came across what he describes as an intriguing topic. "I found out what [Dr. Norman] Franz had been doing with waterjet technology in the 1960s and 1970s," he says. "I decided I wanted to study that for my Ph.D."

Franz, a forestry engineer, was the first person to experiment with ultra-high- pressure water to cut wood. His research and findings were used to develop the first industrial waterjet cutting machine, which gained rapid popularity for its clean and fast cutting of various materials. Thanks to Franz, the waterjet found a niche application in cutting soft goods like leather, tissue, cardboard and food.

Inspired by Franz’s discoveries, Hashish wrote his thesis on the theory of waterjet cutting. "I built my own little waterjet unit and cut different materials, including wood, coal and soft goods," he says. After receiving his Ph.D., Hashish was working on postdoctoral research when the idea of an abrasive waterjet came to him.

"One day, I filled a Styrofoam cup with sand from an ashtray and put it underneath the waterjet, on top of a piece of wood," he explains. "When I fired the jet, it drilled through the wood much faster. That confirmed my idea that adding abrasives to the waterjet would improve it."

Finding success
Hashish was hired by Flow Research, known today as Flow International Corp., to develop his idea of an abrasive waterjet. He used garnet abrasives, a material commonly used in sandblasting and on sandpaper. Hashish says he used every abrasive material he could find, even the ash from the volcanic eruption of Mount St. Helens. With this method, the waterjet could cut almost any material. In 1980, abrasive waterjets were used for the first time to cut steel, glass and concrete.

In 1983, Flow sold the world’s first commercial abrasive waterjet system. Libby Owens Ford Co. was the first company to use the machine for cutting glass for automobile windows and windshields. John Deere, Kodak and Rohr Industries, now a part of Goodrich Aerostructures Group, soon followed as the early adopters of the abrasive waterjet.

The technology took off in many industries, most notably the job shop, stone and tile, glass, electronics, automotive and aerospace industries. Companies like Boeing and Airbus found the abrasive waterjet ideal for cutting high-strength materials like Inconel, stainless steel and titanium, as well as high-strength, lightweight composites like carbon fiber used on military aircraft and commercial airplanes. Most recently, abrasive waterjets were used to cut the SanDisk micro Sd card used in cell phones and digital cameras. "So you probably have an abrasive waterjet-cut part in your pocket," says Hashish.

Hashish’s abrasive waterjet technology allowed the machines to cut materials like concrete and steel up to 2 ft. thick. For example, a nuclear facility in West Valley, N.Y., was decommissioned using abrasive waterjets to cut up to 10-ft. concrete walls. What makes the technology even more unique, however, as Hashish points out, is that the waterjet can cut both thick and thin materials without distorting them or changing them metallurgically.

Waterjet technology became one of the fastest-growing machine tool technologies over the past decade. And it doesn’t show signs of slowing down any time soon, either. "We’ll keep increasing the pressure to maximize its use," says Hashish. "We’ll also try to make the waterjet with a finer, smaller beam to increase cutting capability. It will become more powerful but also more affordable and easy to use." FFJ