Summary
When it comes to buying a cutting machine for your company or personal use, you may consider buying a laser, plasma, or waterjet cutter. But determining which one is suitable for you can be pretty confusing. In this article, I’m going to explain everything about waterjet, laser, and plasma cutters so that you can easily decide which one suits your needs.
But if you are in a hurry then take a look at the table given below that practically summarizes this article.
Quick Navigation
| Machines | Purchase Cost | Operating Cost | Cut Quality and Precision | Cutting Speed |
|---|---|---|---|---|
|
Waterjet |
Expensive |
High |
Excellent |
Very Slow |
|
Laser |
Expensive |
High |
Excellent |
Fast |
|
Plasma |
Cheap |
Low |
Good |
Very Fast |
How Does Waterjet Cutting Work?
A waterjet cutter is an industrial tool that is used for cutting a wide range of materials with high precision. This is a cold cutting process that utilizes a high-pressure water jet or a combination of water and abrasive (usually garnet), which cut down materials crossing its path. It is more like an erosion process that is occurring at a very high speed.
Only water or the mixture of water and abrasives with high pressure is sprayed out over the target material through a ceramic nozzle. This immense pressure (usually more than 50,000 psi) creates a fine cutting stream at the tip of the nozzle. This will break down any material that stands in its way.
The nozzle will move along a predetermined path that is set through the associated CNC software.
How Does Laser Cutting Work?
Laser cutting is an advanced method of cutting materials. This uses focused beams to cut through metals.
The nozzle of the laser cutter utilizes curved lenses to create a spherical focus point of light on the material. The beam of light melts or evaporates the metal, leaving behind an accurate cut with a high-quality edge finish. The cutting process is also aided by compressed gases.
How Does Plasma Cutting Work?
Plasma cutters utilize electricity and compressed gases (usually Argon, Nitrogen, Oxygen, etc.) to cut metals. The gas is forced through the nozzle of a torch at high pressure. At the same time, an electric arc is sent through the nozzle. This will heat the gas to the point where the gas will enter the fourth state of matter, known as plasma.
The plasma is extremely hot which melts metals that are in the way. The excess metal will be blown away by the plasma gas stream. Which gas you should use will depend on the type and the thickness of the metal.
Advantages & Disadvantages of Waterjet, Laser, and Plasma Cutting
Each of these cutters have some advantages and disadvantages. Let’s take a look at them one by one:
Advantages & Disadvantages of Waterjet Cutting:
| Advantages | Disadvantages |
|---|---|
|
Can cut almost anything. |
Abrasive materials are usually very costly. |
|
Doesn't produce any heat-affected zone (HAZ) which is perfect for cutting heat-sensitive materials. |
The cutting process produces a lot of noise if it is not done underwater. |
|
Doesn’t produce any hazardous fumes or waste. |
Has slow cutting speed for most metals. |
|
Produces highly accurate cuts. |
|
|
Works perfectly even on rough surfaces |
|
Advantages & Disadvantages of Laser Cutting:
| Advantages | Disadvantages |
|---|---|
|
Can cut a variety of non-metal and metals. |
Can create microfractures on some metals. |
|
Very energy efficient compared to waterjet cutting. |
Compressed gases are expensive. |
|
Requires minimal human involvement which minimizes the possibility of accidents. |
Can produce hazardous and toxic fumes. |
|
Suitable for cutting thin sheets and complex patterns. |
Laser-cutting machines are significantly costly. |
|
Has a faster cutting speed and is suitable for bulk production. |
|
Advantages & Disadvantages of Plasma Cutting:
| Advantages | Disadvantages |
|---|---|
|
Can cut a wide range of metals. |
Produces large heat-affected zones (HAZ). |
|
Easy to learn and operate. |
Less accurate compared to waterjet and laser cutting. |
|
Faster cutting speed. |
Can produce micro fracturing to some metals during the process. |
|
Great hole quality. |
Produces toxic fumes. |
Waterjet vs Laser vs Plasma Cutting Costs (Purchasing cost & Running/Operating cost)
The initial purchase cost for plasma cutters is the lowest compared to waterjet and laser cutters. The cost of a plasma cutter can range from 15,000 USD to 300,000 USD. However, most of the plasma cutters cost below 100,000 USD. For a waterjet cutter, the price is between 100,000 USD to 350,000 USD.
As for laser cutters, they are the most expensive among the bunch. The cost of a new laser cutter starts from 350,000 USD and can go all the way up to a million USD, depending on the features of the machine.
Other than the purchase cost, plasma cutters are also cheaper when it comes to operating costs. They cost approximately 15 USD/hour whereas waterjet cutters cost 20 USD/hour and laser cutters cost around 30 USD/hour.
Waterjet vs Laser vs Plasma Cutting Quality & Precision
When it comes to the edge quality of the cut, waterjet is undoubtedly the winner. You can get the highest quality cut from the waterjet. The laser cutter is the second best. This is because although it provides a very square cut, it generates some pierce spatter and leaves some dross behind while cutting thick metal pieces.
The plasma cutter has the worst cutting quality among them.
Precision is a measure of the resulting part size compared to the programmed size in the CNC software. Waterjet also holds the top spot when it comes to precision. The laser cutter holds second place as it generates some heat distortion during the process, especially in the case of thick metal pieces.
Plasma cutter again becomes the last place holder because it generates high heat distortion. But this distortion can be reduced greatly by cutting under-water.
Waterjet vs Laser vs Plasma Cutting - What Can It Cut?
From wood to hardened steel or titanium, waterjet cutters can cut almost anything. It is not limited by the thickness of the material or the flatness of the material surface. The waterjet cutter only uses the fine stream of high-pressure water to cut soft materials like rubber or wood.
Abrasives are added to the high-pressure waterjet to deal with tough metals like aluminum or steel.
Laser cutters can also cut a wide variety of materials like plastic, glass, wood, rubber, ceramics, and most types of metals. It is also good for cutting complex patterns on sheets, boxes, or tube sections.
Plasma cutters are less versatile compared to waterjet and laser cutters. You can’t cut wood and any other material that is heat-sensitive using this. You can only cut mild steel, stainless steel, Aluminum, Copper, Brass, and Carbon steel. However, cutting anything thicker than 1 inch using plasma cutters can be a bit tricky.
Waterjet vs Laser vs Plasma Cutting Speed (Speed of Operation)
The speed of operation can vary depending on how many cutting tools you have on your machine. For example, if you have 3 waterjet cutting heads on your machine, it will significantly increase the cutting speed. However, for the sake of the evaluation, I will only compare the cutting speed of smaller machines that have only one cutting tool.
When it comes to cutting speed, waterjet and laser cutters fall far behind plasma cutters. Plasma cutters can cut most of the metals at an unprecedented speed that ranges from 60 to 200 inches per minute. A laser can cut 20 to 70 inches per minute and a waterjet can cut with a speed of 1 to 15 inches per minute depending on the thickness and type of the material.
Waterjet vs Laser vs Plasma - Common Uses
Waterjets can cut almost anything. But this type of cutter is mostly used to cut heat-sensitive materials like plastic or aluminum and when precision is of utmost importance.
Laser cutters can cut metals and non-metals. But the most common use of such type of cutters is to engrave patterns or serial numbers on the material surface. As for plasma cutters, they have the lowest cut quality. This cutter is mostly used in scrapping and salvage industries, automotive repair and restoration shops, metal fabrication shops, and industrial constructions.
Waterjet vs Laser vs Plasma - Max Cutting Thickness
When it comes to the maximum cutting thickness, waterjet beats plasma and laser cutters by a lot. Waterjet cutters can cut up to 12 inches of thick materials. Plasma cutters come in second place with the ability to cut up to 6 inches thick mild steel or stainless steel sheets.
As for laser cutters, their maximum cutting thickness is up to ¾ inches for carbon steel, ⅝ inches for stainless steel, and ⅛ inches for aluminum sheets. One thing to remember here is that the maximum cutting thickness of these cutters varies depending on the material you are cutting.
Waterjet vs Laser vs Plasma - Waste Production
When waste production is a matter of concern between these three, laser cutters come out on top. They produce a very small amount of waste in the form of dust. You can easily clean it off after the cutting procedure is finished. However, both waterjet and plasma cutters produce a huge amount of waste compared to laser cutters.
The mess that water jets leave behind requires quite a bit of cleanup work. And you will need to take extra measures to dispose of the abrasive waste produced during the cutting process. As for plasma cutters, they will produce a lot of waste in the form of slag and dross and require extensive post-cut cleanup.
Waterjet vs Laser vs Plasma - Requirement of Secondary Finishing
Waterjets provide very smooth, precise cut edges with a more sand-blasted look that is free of any sort of burnt edges or slag. As a result, waterjet cuts are considered a finish cut and don’t require secondary finishing. Laser cutting also doesn’t require secondary finishing in most cases.
On the other hand, plasma cutters generally require secondary finishing operations. This type of cutter uses high temperature to cut through materials. Although the flow of ionized gases blows away excess materials from the cut edge, some stay behind.
As a result, the cut edge appears a bit rough. To get a clean and smooth edge, you will need to perform secondary finishing operations in this case.
Common Issues Caused by Each Cutting Method
When it comes to waterjet cutters, they create a lot of noise during the cutting procedure that can damage your hearing. So, wearing ear protection is a must during the entire time when operating a waterjet. Apart from that, there are no known issues with waterjet cutting.
Laser cutters will leave some burn marks at the cut edge and can produce toxic fumes during the cutting process. When it comes to plasma cutters, they will leave a large Heat Affected Zone (HAZ) and produce dross & slag in the cut edge. This type of cutter also produces fine particulate dust and fumes that are hazardous to human health if not controlled.
Conclusion
When it comes to determining the best among waterjet, laser, and plasma cutters, there is no clear winner. There are just too many variables involved that you will need to consider before choosing one. And this article gives you a quick overview of the relative comparison between these cutters so that you can make the decision for yourself. However, the result will depend solely on your priorities.
