What Materials Can a CNC Waterjet Cut?

Professionals often wonder about the capabilities of CNC waterjet cutting. Some common queries are what is CNC waterjet, its types, the different materials that undergo this process, and its performance. This article will explore all these answers and more.

What is a CNC Waterjet?

CNC waterjet is an automated cutting machine based on waterjet cutting technology that uses the force of highly pressurized water for material cutting.

The waterjet is controlled with Computer Numerical Control (CNC) technoogy. CNC programs are pre-written for the particular part beforehand. CNC waterjet is a fully automated, high-precision industrial cutting process.

For cutting soft materials, the force of the water is sufficient. However, for hard materials, the force of the water can lead to a slower cutting process. Therefore, abrasive material is added to the water stream to speed up the cutting action. The process is then called abrasive water jet cutting. CNC can control both pure and abrasive water jet cutting.

How Does a CNC Waterjet Cutter Work?

CNC waterjet cutting is a multistage process. The steps involved are:

1. Designing the Part
An engineering design of the part is created before cutting it. For simple cuts in a straight line, this step can be skipped. However, a detailed graphical design with the measurements is required for complex parts. The graphical design is made in Computer Aided Design (CAD) software.

2. Converting Design to CAM
A CNC waterjet machine does not understand graphical design. It understands CAM language (g-code and m-code). Therefore, the CAD design is converted to CAM in Computer Aided Manufacturing (CAM) software. The CAM file is loaded to the machine control panels.

3. Machine Setup
The operator starts the machine setup for the operations. The workpiece is clamped on the worktable. All the necessary settings are selected and preliminary checks are done.

4. Machine Startup
The machine startup process takes place according to the particular CNC waterjet model. Startup includes the generation of pressure in the hydraulic pump. The hydraulic pump provides pressurized hydraulic oil of around 50 psi to the intensifier. The intensifier increases the hydraulic pressure to 50,000 psi and even more.

5. Execution of Waterjet Cutting
Once the pressure is ready, the cutting operator starts. The water jet cutting head moves around the part while forcing the high-pressure stream of water. The G-code of the CAM file controls the movement. The stream of water is very narrow with a thickness less than a human hair.

6. Unmounting of Part
Once the machining is completed, the part is unmounted from the machine. If the part requires any further machining, the operator mounts it on the worktable again. Otherwise, the part is sent for secondary machining.

What are the Parts of a CNC Waterjet Cutter

CNC waterjet cutting machine comprises of industrial-grade parts that can handle the ultra-high erosion forces at play. The various components of water jet cutting machines are:

CNC Controller
The CNC controller is the brain behind the machine. It reads the commands provided by the software and the settings made by the operator. The combined interpretation is sent to the machine cutting head.

High-pressure Pump
A high-pressure pump creates the necessary force required for the cutting action. It is an assembly of a hydraulic pump and intensifier. The hydraulic pump creates a small pressure which is amplified by the intensifier. The cost of the water jet heavily relies on this part. High-pressure pumps come under multiple settings to adjust the pressure according to part requirements.

Cutting Head
The cutting head is the assembly that moves the stream of water around the work table. A nozzle present in the cutting head focuses the stream of water. There is a mixing chamber before the nozzle in abrasive water jet cutting. The mixing chamber mixes the abrasive material with the water stream.

Abrasive Hopper
The purpose of an abrasive hopper is to store and feed the abrasive material to the mixing chamber. A good quality abrasive hopper can deliver the abrasive material uniformly. Abrasive hoppers can generally store enough material for hours of waterjet cutting.

Gantry
The gantry is the bridge system in the waterjet cutting machine. It provides support to the cutting head and mobile parts of the machine. The gantry bridge system supports the cutting head movement in the X-axis, Y-axis, and Z-axis.

Cutting Table
The cutting table provides a stable base for mounting the workpiece. The workpiece is held securely on the cutting table. Modern waterjet cutters have the feature of underwater cutting. The workpiece can be submerged underwater to provide noiseless and splatter-free cutting.

Water Filtration System
The water filtration system purifies the water and removes any debris from it. This prolongs the life of the components used in the waterjet cutting machine. A water filtration system usually includes a softener for fixing the hardness of the water. The filtration system should be designed based on the type of water source you will use.

Control Panel
The control panel provides a medium for the operator to interact with the machine. Various settings of the waterjet machine can be selected through the control panel. Control panels also come with a display for viewing relevant information.

Software
Waterjet machines come with a software that acts as the language between the controller, the operator, and the machine. The functionality of the software can vary based on the machine. Every Techni Waterjet cutting machine comes with complimentary software. The software contains many basic cutting shapes preloaded in the system.

Different Types of CNC Water Jet Cutting Machines
CNC water jet cutting machines are available in many different configurations. The use of a particular type is based on the requirement of the operation. These different types of machines are:

One-dimensional Waterjet Cutting
One-dimensional waterjet cutting can also be seen as single-axis cutting. In this method, the waterjet cutting heads can only move in one direction. This method is used for straight linear cuts. Generally, this technique is applied to the processing of raw materials.

Two-dimensional Waterjet Cutting
Two-dimensional waterjet cutting is also known as 2-axis waterjet cutting. The cutting head can move on the X-axis and Y-axis. These machines can cut linear as well as circular cuts. However, they cannot create inclined surfaces or curved cuts in the vertical plane.

3-axis Waterjet Cutting
3-axis waterjet cutting machine can move the cutting head in the X-axis, Y-axis, and Z-axis. The X-axis is left and right movement across the worktable. The Y-axis is the top and bottom movement across the worktable. The Z-axis is the vertical movement perpendicular to the worktable.

4-axis Waterjet Cutting
4-axis waterjet cutter can move in the linear X-axis, Y-axis, and Z-axis. In addition, it can also move in the rotary A-axis. A-axis is the circular axis around the X-axis. 4-axis waterjet cutting can make curved cuts and machine five sides of the workpiece.

5-axis Waterjet Cutting
A 5-axis waterjet cutting machine is the most capable option among the different types. It can cut linearly in the X-axis, Y-axis, and Z-axis. In addition, the cutting head can also move in any two of the A-axis, B-axis, and C-axis. A-axis is rotary around the X-axis, the B-axis rotary around the Y-axis, and the C-axis rotary around the Z-axis. 5-axis cutters can create linear, curved, and inclined parts. It can also craft parts with internal features and geometries.

What Materials Can a CNC Waterjet Cut?
Waterjet cutting can cut through virtually any material except for only diamond and tempered glass. Some of the common materials that undergo waterjet cutting process are:

Metals
Metals and metal alloys commonly undergo waterjet cutting process. Some of the common metals utilizing this technique are:

Stainless Steel (all grades)
Aluminum
Carbon Steel
Mild Steel
Tool Steel
Copper
Brass
Iron
Chrome
Nickel
Titanium
Platinum
Gold
Glass
Glass can be delicate to cut through traditional means. However, waterjet cutting can pierce and smoothly cut any type of glass with ease. Some common examples are:

Plain glass
Frosted glass
Reinforced glass
Mirrors
Glassware
Stone
Waterjet cutting stone and tiles is a very common application of the method. It finds common application in kitchen countertops, flooring, cladding, and other areas. Some of the common stone and tiles cut by CNC waterjet cutting process are:

Marble
Granite
Tiles
Porcelain
Silestone
Caesarstone
Composites
Composite metals are made by fusing multiple materials together. Composites can be tough materials for conventional cutting processes. However, waterjet cutting can easily cut it. Some of the common composites cut with water jet cutting are:

Fiberglass
Fibre Reinforced Plastics
Carbon Fiber
Plastics
Water jet cutting provides a lot of benefits when cutting plastics. CNC waterjet is a cold cutting method. Therefore, plastics do not release toxic fumes on being cut with water jet cutting. Some of the common plastics that undergo water jet cutting are:

ABS
Styrene
Polythene
LHDP
UHDP
Nylon
Rubber
CNC waterjet cutting also shows exceptional performance when cutting rubber. While rubbers are soft materials, conventional cutting processes create heat which can cause the rubber to harden. However, waterjet causes no such issue. It can cut any rubber with extreme precision.

Paper Products
CNC waterjet cutting is common in the paper industry. It applies to paper, paper reams, and paper based products like cardboard. Due to the softness of paper products, pure water jet cutting is enough to accomplish the task.

Wood
CNC waterjet cutting of wood is usually implemented in the furniture industry. Water jet cutting process can create intricate shapes from wood, such as carvings. Waterjet cutting can also cut plywood without causing any delamination issues.

What is the Maximum Thickness of CNC Water Jet Cutting For Different Materials?
Waterjet can cut most materials up to 24″ in thickness. The range of maximum thickness of water jet cutting varies based on the type of material. For instance, it can cut hard metals and alloys up to a thickness 12″ to 18″ (depending on the machine). It can cut soft materials many times that thickness.

The maximum thickness does not mean that a water jet machine is limited to that value. Theoretically, the water jet cutting process can cut any thickness of any material. However, the cutting time increases significantly beyond a certain thickness. Additionally, thicker materials lead to slower cutting speed. The maximum thickness is the value after which the cutting speed and time can become unfeasible.

How Accurate is CNC Waterjet Cutting?

CNC waterjet cutting can have a tolerance as low as ± 0.002”. This makes CNC waterjet cutting one of the most accurate cutting methods. The exact tolerance of water jet cutting process depends on the particular material being cut. Maintaining the machine and doing the setup right can increase the precision of waterjet cutting.

Applications of CNC Water Jet Cutting
CNC water jet cutting is used in many different industries and sectors. Some of these areas are:

Aerospace: Water jet cutting can create the niche parts required in the aerospace industry. The high precision of water jet cutting technology makes it an attractive option for the aerospace sector.
Automotive: Automotive industry relies on the waterjet cutting process to create precise and consistent parts. This includes everything from car frames to engine components.
Medicine: The Waterjet cutting machine makes surgical equipment and other medical devices. Waterjet creates clean and hygienic cuts, leading to great demand in the healthcare industry.
Electronics: The narrow thickness of waterjet cutting makes it ideal for use in the electronics industry. It commonly applies to cutting frame parts for electronic products like phones and smartphones.
Art: The customization offered by waterjet cutting makes it ideal for cutting art products. For instance, waterjet cutting can create sculptures and architectural installations.
Signage: Waterjet provides a smooth surface finish to the material along with superior edge quality. The signage industry uses these qualities to create brand logos, nameplates, signs, and more.
Food and Beverage: Water jet cutting is a no-contact technology. The high hygiene of the process makes it ideal for cutting food products and in the food packaging sector.
Benefits of CNC Waterjet Cutting
The CNC water jet cutting process provides many advantages that are unmatchable with other cutting techniques. Some of these benefits are:

No Heat-affected Zones: Heat-affected zones are caused by localized heating due to cutting friction. Water is a coolant in itself. Therefore, water jet cutting causes no heat-affected zones.
Preserving Material Integrity: The material integrity remains intact due to the absence of heat zones. There are no burn marks on the material surface.
Precision: The narrow stream of water results in a very high-precision cutting process. Water jet cutting has higher accuracy than alternative cutting methods.
Edge Quality: Water jet cutting has a superior edge quality. This is the result of the material erosion that takes place on a particle level. Waterjet cut parts require no secondary finishing.
No-contact Cutting: Water jet cutting does not require the contact of the tool with the workpiece. The high-pressure stream is enough to make the incision. This reduces the tool wear and calls for less frequent tool changes.
Costs: Water jet cutting keeps the cost of operation manageable. Pure water jet cutting is a very cheap process. Abrasive water jet cutting has the cost of abrasive as the primary operational cost.
Versatile: Waterjet cutter is the most versatile cutting option out there. It can handle all cutting materials regardless of their shape or form. This includes metals, non-metals, ceramics, composites, glass, paper, etc.

What is the Cost of a CNC Waterjet Machine?

The average cost of a good CNC waterjet machine is $100,000. You can find cheaper models starting at $50,000. However, these models will lack the quality and features that any job requires. Therefore, if buying a new waterjet CNC machine, $100,000 can be a good initial investment. The exact cost of CNC waterjet cutting machine can vary based on several factors.

What is the Expected Lifespan of a CNC Waterjet Cutting Machine?
Waterjet cutting machines can easily last for over 25 years. However, some parts of the machine have a shorter lifespan and require frequent replacement. These parts include the nozzle, seals, valves, tubes, and other components dealing with the high pressure stream.

What are the Safety Considerations For a CNC Water Jet Cutting Machine?

A CNC water jet cutting machine is an industrial tool. The forces it generates can cut the hardest material. Therefore, it requires extreme safety considerations. No human tissue should come under the machine during equipment operations. The machine should be operated by skilled professionals only. The operator requires safety training on the machine before using it.

Maintenance Schedule For CNC Waterjet Cutting Machine
Following the correct maintenance process for waterjet cutter can result in high quality operation and long equipment life. Some of the important maintenance considerations are:

Check the degree of wear for parts such as nozzle before operations. A worn out nozzle can result in poor quality cuts.
Drain the pneumatic filter regulator of the machine every week.
Release the build-up gases in the waterjet machine every week. Water vapor buildup can be a common issue in a waterjet cutting tool.
Regularly clean the water strainer. The frequency depends on the type of materials you cut.
Grease the various bearings of the machine once every year.

How to Choose a CNC Water Jet Machine?

Going through a detailed buying guide for water jet machine can help in making an informed decision. Some of the important factors to consider when choosing a new water jet are:

Pump Pressure: Pump pressure depends on the type of materials you want to cut. Required cutting speed also plays a crucial role in this.
Abrasive vs. Pure Water Jet Cutting: Pure water jet cutting can be cheaper for soft materials. However, hard materials require abrasive waterjet technology.
Brand Value: It is better to go with a reputed brand, even if it costs you a little extra. Machines with good build quality can avoid downtimes and operational losses.
Spare Parts: Ensure that the spare parts for the machine are available when required.
Techni Waterjet’s G2 series is often considered the best by professionals in many different industries. These machines come with a rugged build quality and the features of waterjet machines that are twice the price range. The machines come with a complimentary software with preloaded programs for basic cut shapes.

What is the Difference Between CNC Laser and CNC Waterjet?

CNC laser and CNC waterjet both utilize Computer Numerical Control. However, there are vast differences between CNC laser and CNC waterjet cutting. The waterjet process is considerably better than laser cutting. A laser uses high-energy light rays to melt the material. This leads to adverse heat effects on the material. The materials can require secondary finishing due to burn marks.

However, the waterjet process does not create any adverse effects. Additionally, the waterjet can cut through virtually any material. CNC lasers have shortcomings in this area. Materials like plastics release toxic fumes when heated. This can damage the laser tubes, rendering CNC laser cutting unusable.

Endnotes
CNC waterjet is a breakthrough technology for cutting hard materials and soft materials. The precision and versatility of the process are very incomparable. Additionally, being a cold-cutting process, a waterjet cutter is a more attractive option than alternatives such as plasma cutting.

If you are considering getting a new machine for your fabrication shop, CNC waterjet can be the perfect choice. Get in touch with Techni Waterjet to know the right fit for your requirement.

XTJ is a leading OEM Manufacturer  that is dedicated to providing one-stop manufacturing solutions of Machining 6061 Aluminum  from prototype to production. We are proud to be an ISO 9001 certified system quality management company and we are determined to create value in every customer relationship. We do that through collaboration, innovation, process improvements, and exceptional workmanship.