One of the critical factors for efficient water-jet cutting is the height of the jet nozzle from the workpiece. That's where Water Jet Sweden focused its attention with its new height-sensor setting system. WJS supplies profile cutting equipment in various sizes for different applications.

If the gap between the cutting nozzle and the material is too large or too small, cutting efficiency will be reduced, and as a result operating speed will be lessened, too. Another result is that the quality of the profiled edge deteriorates, requiring remedial or even product rejection.

The critical distance between the nozzle and the material should be just a few millimeters, but WJS says the new sensor is able to maintain this distance within a tolerance of +/- 0.1 mm. This ensures a position of 2.5-3.0 mm across the whole working area, which can be extended up to 4×12 meters.

For users, this brings benefits in greater cutting efficiency and cleaner edges at no extra cost.

When this operation is carried out through the CNC system, several functions are involved. The operator enters any desired figure for the distance that is to be held between the material and the cutting head. The measurements can be set on-line or, at specific time intervals e.g., every 10 seconds. The head will follow these instructions reliably throughout the cutting operation.

In addition, the new height sensor system can be fully-integrated with a new WJS anti-collision monitoring device. At the conclusion of each operating cycle the cutting system will automatically raise the head clear of the surface as a safety measure to help protect the expensive jet nozzle from accidental damage during workpiece retrieval.

The new system brings advantages to users who process profiles from large sheets of material. Such materials may have significant bows and buckles across their width or length, which significantly complicate the profiling process. Processors of smaller profiles also benefit from the system because it cuts down on the initial set-up time, improves productivity and reduces the need for skilled operator oversight of the cutting process.

New installation

A recent application of Water Jet Sweden's cutting technology is at ThyssenKrupp Materials International's Logistics Center in Dortmund, Germany, a stainless steel and nonferrous materials processing center. The operators there invested in new WJS cutting technology to increase throughput and lower operating costs.

The Dortmund plant processes up to 1,900 metric tons/day of material. It's described as a “first-stage processing center” for manufacturers and fabricators of stainless steel and nonferrous metals. It operates three shifts/day with up to 300 work cells arrayed over more than 50,000 m2. Available processes for finished or semi-finished parts include sawing, flame cutting, laser cutting, grinding, water-jet cutting, tubing laser, and foiling. All shapes and sizes of tubes, steel bars and sheets of stainless steel and nonferrous materials are processed.

Marcus Raback, Logistics Center Dortmund works director, explains that the plant “executes a significant portion of the total added value manufacturing in the whole of Germany in this sector.”

Traditionally, parts cutting has been done by sawing, or laser or plasma cutting. However, the rapid adoption of water-jet cutting throughout manufacturing over the past 10 years (since the first machines were widely installed), prompted ThyssenKrupp Materials to look at the comparatively new technology for heavy-duty cutting.

After reviewing bids from several water-jet cutting machine builders, ThyssenKrupp chose Water Jet Sweden based on its technical ‘know-how' and engineering skills, and for its demonstration of the ways that water-jet cutting could improve productivity and lower costs at Dortmund.

The management at the Logistic Center was impressed with the new system's efficiency, accuracy, speed, finish, flexibility and versatility, and reliability. In addition, they appreciated Water Jet Sweden's operator training and after-sales service, including the on-going supply of materials, replacement of worn parts, and future technological upgrades. (At Dortmund, the consumption of abrasive used in water-jet cutting of very hard materials totals to 1 metric ton/day.)

ThyssenKrupp Materials chose the WJS NC 3560 DL, with a 6-m long cutting table to achieve maximum profile lengths, and linear drives. The main advantages of these features are that they require virtually no maintenance, have the ability to move the two cutting heads independently in the X direction, accurate cutting to within 0.05 mm, and positioning speeds of up to 30 meters/min.

The NC 3560 DL also incorporates the advanced Siemens 840D CNC system, especially adapted for Water Jet Sweden machines.

Wastewater cleaning

One design feature of this installation that's particularly valued by ThyssenKrupp Materials is a special wastewater cleaning system, capable of cleaning 3,200 liters/day of wastewater prior to discharge into the drainage system.

According Marcus Raback: “The advantages of water-jet cutting over other methods go further than the first, obvious one of cold cutting. Laser and plasma cutting are only suitable to a limited extent for machining aluminum and titanium, and due to insufficient up-time capacity and expensive running cost they are not quite ideal. Water-jet cutting up-time capacity of 90% is outstanding.”

Raback stated that ThyssenKrupp Materials expects that its customers also will benefit from its use of water-jet cutting. “Many of them now, when placing their orders, specify that we use water-jet cutting in our processing preparation work before delivery. Advantages they appreciate are the beneficial effect of the cold cutting of the water jet on the material, accuracy, superior finish, absence of burred edges, and elimination of added preparation work, which previously they had to do for themselves.”

OMAX Unveils New Line of Abrasive Water-Jet Machines

OMAX Corp. is introducing a new line of abrasive water-jet machines that will appeal to operations where affordability is a guiding factor in the choice of equipment. It describes the MAXIEM line as machines that incorporate its proven technology for high-pressure cutting in an affordable, highly productive package.

“Through years of marketing the OMAX line of JetMachining Centers, we recognized the strong demand for a line of basic abrasive water-jet equipment,” OMAX CEO Dr. John Cheung explained. “With the new MAXIEM line, we meet this demand, as well as the varying performance needs required by the international community.”

MAXIEM will be a separate brand from the current OMAX offerings, with a different market profile in terms of cost and function.

“As water-jet technology has evolved, the precision and accuracy of OMAX machines has moved beyond the point of what some manufacturers require,” detailed Dr. John Olsen, co-founder and vice president of operations for OMAX. He described MAXIEM as an “entry-level line of abrasive water jets,” and one that is well timed to the financial concerns of the machine shop market.

The targeted MAXIEM users will be fabrication shops, metal service centers, trade schools, and job shops. OMAX further identifies shops that specialize in architectural work, signs, stone, and gaskets, or any operation that processes large parts or multiple parts from large stock, including metal, plastic, glass, ceramics, stone and composites.

The first machine to be available will be the 1530MX. It will have a 1.5×3-meter table size; a smaller, 1.5×1.5-meter version (MAXIEM 1515) will be introduced in the coming months, and other sizes will follow. All MAXIEM designs will have OMAX Intelli-TRAX™ traction-drive technology (developed to perform in the abrasive atmosphere) in the X-Y axis, and a motorized Z axis. The 50,000-psi pumps will be offered in 20 and 30 horsepower options.

The OMAX Intelli-MAX Basic control package will power the MAXIEM machines, including its proprietary control software.