Asia Stone Link (July - Sept. 1999)

 As you step over the threshold into the elegant foyer of a banking executive, you notice a beautiful design cut by a waterjet. The owner of this impressive home was able to save hundreds of dollars because the waterjet operator used a Waterjet Abrasive Recycling Dispenser (WARD), which decreased the costs associated with waterjet cutting. The design was crafted with different types of stones & marbles. A closer look reveals inlaid brass encircling the artistic, yet distinguished symbols formed by red and white marble. Your gaze is transfixed on this captivating medallion as your host welcomes you into his luxurious, neo-classical home in Singapore.

Medallions are being installed in hotel lobbies, government buildings, businesses and private homes, as the waterjet industry once again proves its ability to cut intricate shapes quickly and cleanly. As companies involved in all aspects of the hard surface business endeavored to fill the need for custom, personalized designs in stone, marble and ceramics, they turned increasingly to the fast-developing waterjet technology. Today, due to the advancements in controllers and software, employers are finding it easier to train their waterjet operators. With innovations such as hand-held pendants, optical eyes, etc., waterjet cutting has entered the realm of plausibility.

Utilizing water alone, waterjets cut food, foam, cardboard and other soft materials. By adding abrasive, waterjets can pierce and cut aluminum, steel, inconel, titanium and, of course, stone, marble and ceramic tile. Most waterjet cutting requires garnet as the standard abrasive for almost every cutting job. As every waterjet operator knows, the garnet is the most expensive component of waterjet operating costs, occupying up to one-half of the cutting costs. With garnet costing as much as $0.32/lb., waterjet companies are constantly searching for ways to reduce their expenses. With the advent of abrasive recycling, the entire waterjet industry has changed radically, as operating costs plummet.

The Waterjet Abrasive Recycling Dispenser (WARD) is opening doors in areas where waterjet cutting was cost-prohibitive, due to the expense of abrasive. As waterjet operators recycle the abrasive, they are recovering as much as 70% of the garnet! This means that a stone-cutting company using a waterjet with a 50 hp pump nine hours a day and purchasing their abrasive for $0.28/lb. would save an estimated $3,000 per month. This does not include the additional savings on removal and disposal costs when the waterjet tank must be emptied. Since the waterjet cannot be operating while the tank is being cleaned out, the downtime reduced earnings as well as increased labor expenses. Both of these issues are addressed with a WARD. The WARD stores the reusable abrasive in a hopper and the sludge is collected in a drum for easy disposal. By recycling their abrasive once, twice or even three times, companies are becoming more competitive with their job quotations and are able to secure more work.

The WARD 24 (WARD with a 24" diameter primary washing screen) is a state-of-the-art system developed over the past 2 1/2 years with the express purpose of recuperating as high a percentage of reusable garnet as possible. During the cutting process, some garnet particles become marginally smaller and others too small for reuse. The WARD 24 recycles all of the garnet larger than 100 mesh, some of which could actually be sharper than its original state. These sharper garnet particles are created when a particle breaks in two, exposing jagged edges which cut better. In one test 22 percent of the original garnet never decreased in size at all, since it was propelled down the stream without ever coming in contact with the material being cut. Because of these and other factors, there is generally no marked difference in cutting speed when using recycled abrasive!

This innovative recycling process begins with a patented nozzle with no moving parts. This nozzle, contrary to all expectations, works best when buried under at least 12" of sludge. This eliminates the need to operate the WARD 24 constantly every day and allows the operator to activate the recycling process as it becomes necessary. It removes the sludge from the bottom of the waterjet tank and pumps it to the top of the WARD 24 for the initial screening and washing. All garnet smaller than 100 mesh falls through the screen and is delivered with the fines to a disposal hopper or drum. The larger abrasive screened off the top moves into the fluid bed dryer, where it is dried at 150° C in approximately three minutes. After being dried, it passes over a secondary screen to remove oversized particles, with the recycled abrasive dropping into a hopper, ready for reuse.

The WARD 24 is revolutionizing the waterjet industry through the savings attained through recycled abrasive. Companies using their waterjet for more than four hours a day are seeing the immediate savings by recycling their abrasive. As abrasive recycling substantially lowers stone cutting costs, it is predicted that more waterjet systems will be sold. The revolution in waterjet abrasive recycling has begun!