Waterjets

Mulitaxis heads, high-pressure pumps, new software spur waterjet technology

December 1, 2009

A 60-degree multiaxis head allows operators to create highly complex, extremely accurate parts that could never before be made on a waterjet.

Like any technology, manufacturing equipment is constantly evolving.

In the world of waterjets, this evolution generally has been the result of the need for better parts, increased cutting speed, and reduced taper. These three needs also are very closely linked. As taper is reduced, for example, better-quality parts are produced.

Also, an interesting byproduct of higher cutting speed is reduced costs. Increased cutting speed can be accomplished, in part, by increasing the pressure at the pump. This produces a smaller, faster stream of water that uses less abrasive.

History shows us that pump pressures are constantly going up because it’s no secret that pressure equals productivity. Pumps in the waterjet industry typically are rated at 55,000 to 60,000 PSI. However, new products are emerging that are pushing the envelope in high-pressure technology.

One example is Flow International’s recently introduced HyperJet® 94i™, a 94,000-PSI pump.

“Parts are produced 40 percent faster with 40 percent less abrasive, allowing for increased productivity with a significantly lower per-part cost than traditional intensifier pumps,” said Tim Fabian, market manager for Flow.

In addition, the company also has introduced a line of hybrid pumps called HyPlex®. These pumps incorporate technology from the 94i pump in a direct-drive pump package.

“The result is 60,000-PSI pressure, the highest for a direct-drive pump in the world, with seal life never before experienced in a crankshaft pump,” said Fabian.

With abrasive costs comprising more than two-thirds of an abrasive waterjet’s operating costs, it quickly becomes apparent why this is such a significant step forward.

“The waterjet industry is always after the same things,” said Fabian. “They want parts cheaper, faster, better, and they want to create them with an operator using an intelligent control that is exceptionally easy to use.”

Software and Control Technology

A dual pressure valve enables low-pressure piercing operations without waiting for the pump to raise or lower to the desired pressure.

Waterjets use a flexible stream to cut, and this produces a unique challenge when compared to other machining processes such as milling and turning, which use a rigid tool.

“Flow has a team of engineers that work solely on predicting stream behavior during the cutting process,” said Fabian. “The result of this effort is Flow’s SmartStream™ technology, which features the cutting models for over 100 lab-tested materials built right into our control.”

With the control, operators simply select the material they wish to cut, enter the thickness and desired surface finish, and the software and control generates the desired part. Predicting stream behavior is vital to producing accurate parts in a timely manner.

Also important is designing the right control software. According to Fabian, it is no longer enough to be easy to use, if power is sacrificed.

“Designing something simple yet powerful is the key to successful waterjet cutting software,” said Fabian.

Flow offers distinct software packages with its Mach 2, Mach 3, and Mach 4 waterjet lines. Mach 2 and Mach 3 have FlowMaster®, the easiest-to-use package, according to Fabian. FlowXpert™ software, used on the Mach 4 waterjet line, has 3-D modeling capability, and the company’s FlowConnex® package sends text messages or e-mails to alert users of potential machine problems while running unattended.

“FlowConnex also monitors productivity and generates weekly utilization reports. Most importantly, it still uses SmartStream technology and allows a user to produce a fully functional program in less than one minute,” said Fabian.

New machine technology must also keep up with these changes.

Flow has created the Dynamic Waterjet® line. With this machine, novice operators with no training simply click a button and the software automatically tilts the jet to eliminate cut part errors common to all waterjet machines - specifically, taper and stream lag.

Dynamic Waterjet, now standard on nearly all Flow abrasivejet machines, was designed to reduce cycle time and improve tolerances.

The latest machine development from Flow is the newly introduced Dynamic Waterjet XD. This takes all the features of previous Dynamic models and applies them to 3-D shapes and bevel parts.

“A user can now program a 3-D shape in less than one minute, and cut it to tolerances as accurate as 0.001 in. for many patterns,” said Fabian. “This product marries the advancements of Dynamic Waterjet to a 60-degree multiaxis head with FlowXpert software. Using the Dynamic XD, [operators can create] highly complex, extremely accurate parts that could never before be made on a waterjet.”

Emerging Markets

As manufacturers look for new supply chains to enter, new technology often can provide a means of entry.

The aerospace market has embraced waterjet technology easily because these machines are not limited by the type of material they can cut.

“Extreme-pressure waterjet’s ability to hold better tolerances make waterjet a better choice for the extremely tight-tolerance operations inherent in the aerospace industry,” explained Scott Wirtanen, Jet Edge Northeast regional manager.

Extreme pressure, designated xP by Jet Edge, addresses what has been considered the two major drawbacks of waterjet technology - speed and taper.

“With increases in speed and reduction in taper in percentages of 30 to 40 percent, customers are finding that extreme-pressure waterjet technology is the best fit for their application,” said Wirtanen.

Other market sectors also can find waterjet technology of use, especially in high pressures.

“The increased cutting speeds associated with extreme-pressure technology allow our customers to compete with technologies that had advantageous positions prior,” said Wirtanen. “This provides many more opportunities for them to take on work associated with the growing energy industry as well.”

New technology from Jet Edge is also allowing its customers to work at high pressures but also reduce the pressure for piercing operations.

The company’s Dual Pressure Valve® can increase waterjet cutting productivity by allowing operators to control water pressure independent of the waterjet pump.

With the remotely mounted system, waterjet operators can run multiple waterjet tables simultaneously at various pressures with a single pump. They also can perform low-pressure piercing operations without waiting for the pump to raise or lower to the desired pressure, saving time and reducing wear and tear on pump components.

This technology will operate with any manufacturer’s waterjet pump, cutting head, or waterjet cutting system, and it is configurable for pressure change ratios. The system is pneumatically operated and must be used in conjunction with another normally closed on/off valve or cutting head.

For more information, visit www.flowcorp.com and www.jetedge.com.