Stone World

Specialized Stoneworking: <br>Waterjet technology leads fabricator into the stone industry

September 18, 2001
Over recent years, advances in waterjet cutting systems have offered firms the ability to cut diverse materials with a single machine, prompting firms from other sectors to enter into the stone fabrication industry. An example of this can be found in PIW, Inc., of Lockport, IL, which introduced its waterjet cutting services four years ago. Since then, the company has seen this area of business grow to 20% to 30% of its overall business, and open up a whole new line of work in the stone industry.

The company began as iron workers and miscellaneous metal contractors, but chose to take a different route in the 1980s, specializing in architectural metals. Later, in the 1990s, they found themselves providing the same fabricating services to the contractors they used to compete against. The shop has acquired a substantial line of metalworking and fabricating equipment, including CNC vertical machining centers, milling machines, cutting machines and more. "We like to say we have a very large tool box," said company Vice President John D. Shepherd, adding that the waterjet machine has proven to be the most flexible and useful tool in the box. "We use the waterjet for just about everything. It's the most useful tool I've ever seen. If you took away everything in the shop, the last thing I'd give up is the waterjet."

In addition to traditional straight-line cutting, PIW uses waterjet for etching a wide variety of materials - from metals to marble, granite, glass and all types of tile. "The waterjet etching process has been perfected at PIW and is now replacing many of our CNC machine operations," Shepherd said. PIW's waterjet machines cut everything from 1-foot-thick slabs of marble to intricate interior cuts and small, nested pieces of stone to be joined in floor designs and logos. The machines have also been used to fabricate bevels for countertops and stairs.

"A lot of people think of waterjet as cutting only flat material," Shepherd said. "We have a programmable Z-axis that allows us to follow a contour. The Z-axis offers 12 inches of vertical adjustment, so we can cut thick materials." Additionally, the waterjet has provided the company with a very high level of precision in its cutting. "With waterjet, you get such a narrow kerf you can use both sides of the part. With marble and granite, the contractors often look for a very tight joint for grouting. We can hold very tight joints of 40 or 50 thousandths of an inch.

PIW uses an ESAB Hydrocut high-rail waterjet system featuring a 12- x 12-foot table and three cutting heads. The ultra-high pressure intensifier pump produces output pressure up to 60,000 psi. The Hydrocut comes in low, mid, high and pedestal rail configurations. The high rail model offers the size and mass to stand freely without a horizontal brace, allowing ease of access for loading and unloading, according to Shepherd. "It's a very substantial machine with a big work envelope," he explains. "It's also very open for easy handling of large material."

PIW uses a crane to manipulate the large, heavy slabs of stone needed for larger jobs, such as cutting sink cutouts and round corners for granite countertops. The open structure makes it much easier to manipulate the material into position, according to Shepherd. "The table grating can hold a 5,000-pound piece of material," he said.

After obtaining positive results with their first ESAB waterjet system, PIW had the company retrofit an 8- x 30-foot plasma cutting system into a second waterjet system, and a third machine was retrofit with a new ESAB Vision PC control. The Vision PC control offers definite advantages over competitive controls, according to Shepherd. "The Vision control allows better control of the waterjet stream," he said. "Special software from ESAB automatically programs the cut speed, automatically ramping at the corners to ensure the quality of the waterjet cutting stream for better cut quality. This software allows you to cut a variety of materials without the difficulty of reprogramming for each material."

Additionally, the ESAB control's unique "Process Data Generator" automatically creates parameter files for optimum cut quality on any material. The operator simply selects the desired parameters, and all the process variables are adjusted automatically. Kerf, speed, dynamic axial piercing, corner deceleration and acceleration are all set automatically by the control, greatly reducing process set-up time and eliminating guesswork. "It's a very easy control to use," Shepherd said.

PIW does its programming off-line, transferring the file to the cutting machine via network cable or floppy disk. The Hydrocut provides a 125 MB floppy disk drive, which PIW uses for program storage as well as transfer operations. The company can create the program from its customer's sketches or from CAD files or vector art, and nesting software helps maximize material usage.

Although architectural metals are still its main business, PIW looks forward to expanding its business even further in the stone industry. "We're looking for a possible partner in the stone area to work with in developing metal inlay/stone combinations," Shepherd said, adding that he is looking to promote the company more heavily in the stone industry.