Waterjet cutting has been one of fastest growing machine tool processes worldwide over the past two decades. It’s a cold-cutting process that can easily and effectively cut almost any material without adding additional heat or stress. This lets manufacturers produce batches of any size quickly, even for the toughest projects.
Ultra-high-pressure (UHP) jet streams guarantee higher cutting speeds and faster travel rates, increasing the speed at which abrasives hit the material. Flow is – and always has been – on the leading edge of UHP waterjet cutting.
High Pressure vs. Lower Pressure
When first introduced, UHP waterjets had pressures around 36,000 PSI, moving up to 55,000 PSI by the end of the 1980s and 60,000 PSI by the mid-1990s.
In 2004, Flow took us into the age of hyper-pressure – introducing the HyperJet Pump, which boasts 94,000 PSI.
With abrasive waterjet cutting, the particles in the waterjet stream erode the material, making the cut. Higher pressures increase the kinetic energy of abrasive particles within the waterjet stream. As water and abrasive particles move faster, the jet diameter decreases while the power density and efficiency increase. Essentially, more energy is focused on a smaller area, making the abrasive particles more efficient.
Alternatives attempted to boost productivity include:
- Increasing Horsepower: This method lets the waterjet move faster, but requires additional abrasive.
- Using Multiple Cutting Heads: This approach splits power between the heads, which negatively impacts throughput and requires the operator to consistently make sure both are cutting at the same level.
- Using More Aggressive Abrasives: This drives up operating costs and causes premature wear-and-tear on the mixing tube nozzle (5-10 times faster than normal)
The only non-UHP option that actually increases productivity is optimizing toolpaths. Modern, advanced waterjet machines feature built-in toolpath optimization to speed up on straight lines and slow down on tighter turns, controlling anomalies with the finished part and shortening part cycle times.
Increasing pressure remains, however, the best way to boost productivity. Running at or above 87,000 PSI cuts abrasive use in half and dramatically reduces pierce time. Shorter cycle times also mean you can produce more parts per hour and day, increasing profitability and reducing cost per inch.
Higher Pressure Means More Productivity
As pressure increases, so too does the speed of the stream. The water pressure converts into velocity when it exits the cutting head. A faster waterjet stream means the abrasive particles will move more quickly and remove more material, helping you use less material per length of cut.
Boost Pressure, Not Horsepower
Every pump will have a maximum operating pressure, which means to really gain the benefits associated with a higher velocity stream, you need a pump engineered to operate at higher pressures.
As an example, a 60,000 PSI running at 50 HP has the same abrasive consumption as an 87,000 PSI pump running at 100 HP. The key difference is that the higher pressure pump produces a faster moving stream, which cuts at roughly twice the speed. This cuts the garnet use – the main cost driver – in half. With consistent horsepower, the higher pressure pump will use nearly half the abrasive and cut faster.
It is expected that we will see a 25-30% increase in pump pressure over the next 5-10 years. Waterjet velocity will rise accordingly, boosting cutting efficiency. Manufacturers will need to boost productivity, relying on higher pressure systems to remain competitive.
Westway Machinery is the exclusive distributor of Flow machinery – the global leader in waterjet cutting solutions – in Ontario, Quebec, and the Maritimes and the exclusive parts depot for Flow products Canada-wide. Contact us today to learn more about our products and services!
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