Waterjet Machining 101: How a Waterjet Cutting Machine Works

The waterjet machine is quite a marvel 21st-century technology. However, as early as the 1800s, the waterjet was a critical part of many operations in the United States. It was used in the mining and manufacturing industry for precision cutting of the manufactured products.

We credit Dr. Norman Franz for inventing and commercializing the waterjet machine in the 1950s. He realized that waterjet machining was a way easier and cheaper method to cut lumber. Since his invention, there have been many iterations and improvements to the waterjet machine.

In this piece, we’ll delve into the nitty-gritty of water jet machining. Exploring the types, their mechanisms, and also look at some of the pros of waterjet machining. That way, you’ll make a well-informed decision when you’re in the market for a new waterjet machine.

Quick Facts About the Waterjet Machine

The waterjet machine has broad applications in lots of industries. Depending on the machine technology, the waterjet machine can cut through almost every material known to man. Quite ironic, if you consider water, a liquid that’s not too dense is the material that cuts through the hardest rocks.

Waterjet machining saw its technological boom between the 1970s and 1990s. The principles, however, remained the same from the 1950s with a few tweaks to make it more efficient and more powerful.

Water jet cutting is an excellent alternative to blade cutting. It is very precise, plus the technique also leaves no residue. Here are a couple of facts about waterjet machining:-

Has an Accuracy of About 0.0001 Inches and Even Lesser

Waterjet machining can create extremely sharp corners with an equally extremely high degree of accuracy. This accuracy is partly because waterjet cutting doesn’t involve heat.

You see, when a material heats up, it expands, and that expansion ruins the cutting accuracy. That’s why most people prefer waterjet because of its high degree of accuracy.

Cuts Through Most Material

Again, most materials can’t withstand the cutting power of a waterjet machine. Waterjet machines cut through iron, rubber, plastic, and glass. The only thing the machine can’t cut through is diamond and tempered glass.

Produces Pressure Reaching up to 1600 Psi

Your typical waterjet machine will produce between 500-700 PSI. However, some machines can produce up to 1600PSI for more advanced waterjet machines.

Can Use Upto a Gallon of Water by the Minute

Usually, a waterjet machine will use about half a gallon to a gallon by the minute. That’s really a small amount of water compared to your average garden hose or sprinkler system, which uses almost 15 maximum per minute.

It’s a Centuries-Old Invention

Despite all the bells and whistles, the waterjet machine is actually centuries old. However, the waterjet machine of back then didn’t have all the modern features we see today. Plus, of course, it wasn’t programmable like the waterjet machines of today.

The Principles Behind Waterjet Machining

Waterjet cutting involves jetting water at incredibly high speeds under very high pressure through a small opening. The resulting water jet cuts through where it’s aimed at by eroding the material where it contacts.

Sometimes to increase the effectiveness of the waterjet cutting, we add some abrasive material to the water. That way, the waterjet can cut through hard materials like rocks and aluminum.

Types of Waterjets

Waterjets come in two types: pure waterjets and abrasive waterjets. The former cut through light materials like plastic, rubber, and foam. The latter is for harder materials like rocks and metals.

Pure Waterjet

From the “Pure” name, it means that the waterjet is only composed of water. Thus it has no added compounds. Cutting through plastic and rubber with a pure waterjet is a breeze.

Abrasive Waterjet

The abrasive waterjet starts just like a pure waterjet. However, when the water reaches the nozzle, a venturi vaccum pulls in a garnet abrasive that mixes with the water. The resulting waterjet is now a mixture of water and abrasive.

This waterjet can cut through tough materials like iron, rock and glass with ease.

The Basics of How a WaterJet Machine Works

How a waterjet machine works roughly breaks down into three main processes. These processes are simple, so you don’t need to get your physics textbook or open a new Google tab for that matter.

The processes are as follows:-

Pressure Generation

The waterjet must be under pressure to move at high velocity. A pump produces pressure that could reach 94,000 PSI. That’s about 78 times the pressure a typical firehose produces.

Pressure Converts to Speed

To convert this pressure into ultra-high velocity, the machine water passes the water through a tiny orifice. The water jet it creates can sometimes be as thin as human hair.

Garnet for Cutting Harder Materials

To create abrasive waterjets, your waterjet machine must have a garnet that will pull into the waterjet. It will increase the jet velocity by quite a significant margin.

Parts of a Regular Waterjet Machine

You can break down the components of a regular waterjet machine into three parts. These are:-

1. The pressure system- Contains the head, pump and the piping
2. The machine system- Contains the cutting axes
3. The control system-Consists of the motors, operating system and the programming software

Advantages of a Waterjet Machine

1. It cuts cold- That way, there’s better accuracy and no hardening of the material you’re cutting.
2. Environmentally-friendly- produces no harmful gases.
3. Faster- It’s faster than most cutting tools, hence gets more work done in a shorter time.
4. Easy-to-use- Almost anyone can program a waterjet machine.
5. Versatility- The waterjet machine has broad applications and cuts through most materials.

All these advantages must have you thinking when and where did you last see that waterjet for sale sign. Getting a waterjet cutter is almost always a good idea. We advise you to go for it.

Waterjet Machines Will Never Let You Down

Hopefully, you now have a firm understanding of the basics of waterjet machining. Now it might seem like a good idea to get your hands on one of these babies. However, make sure you know how to use the machine first.

However, one thing’s clear; this beauty of modern technology will never let you down.

For more insightful reads, be sure to check out our other pieces.