Waterjet Cutting - The Ultimate Guide
Waterjet cutting industry is regarded as the fastest growing and most versatile industry due to cost-effectiveness. Additionally, waterjet cutter is considered among the most productive machines in the world. Thus, it is vital to learn more about waterjet technology to use the lowest cutting costs and create more profits, as you’ll find out in this article.
What Is Waterjet Cutting?
It refers to an accelerated erosion process within a selected sheet metal material. Alternatively, you can describe it as a versatile cutting process which uses a high-pressure water stream mixed with abrasive media to cut sheet metals into different designs.
Benefits Of Water Jet Cutting
This process guarantees a cutting accuracy of ±0.1 to ±0.2mm hence provides accurate results for internal cut outs and giving quality results.
Since it is a cold cutting process, it offers cost-effective solutions and minimizes time wastage, thus resulting in high profits.
Waterjet cutting offers smooth, even burr-free edge quality since the process combines pressure, water speed, abrasive flow rate, and nozzle size.
This material can cut different types of metals irrespective of the thickness or strength but still attain high quality results at an affordable rate.
It enhances efficiency since you will hardly need to change any operational tool such as nozzle head when cutting new material. Instead, you only need to adjust the feed rate to match required metal type and thickness.
During waterjet cutting, there is no heat-affected zone on the sheet metal material since it is a cold process. Ideally, cold cutting enables clean cuts and enhances operator’s safety by eliminating risks of burns.
It does not form hazardous waste in terms of gases or fumes, unlike other cutting methods used in the industry.
The immediate superior cutting quality ensures an accurate result making additional finishing quite unnecessary. Therefore, it significantly speeds up the cutting process, saves ample time, and increases overall efficiency.
History Of Waterjet Cutting Technology
This technology came into the scope in the mid-18th century, but it was initially used to excavate materials in coal mines. Commercially, it was first used by McCartney Manufacturing in the aerospace industry and later on in manufacturing paper tubes. In 1980, the first abrasive waterjet nozzle was introduced by an Egyptian researcher, and a Chinese company also introduced an efficient waterjet cutting machine.
Motion control system that would help locate waterjet streams effectively was also invented in 1990. Moreover, the development of this technology saw immense growth from the year 2000 when cutting speed was improved significantly. In the last decade, 3D tools and 6-axis machining were also introduced to enhance the efficiency of this cutting technology.
Abrasive Jet Cutting Vs. Waterjet Cutting
Here is how these two cutting methods compare;
- Abrasive jet cutting uses a high-velocity jet of air-abrasive mixture to remove material, while waterjet cutting uses high-velocity pure water for material removal.
- Working medium for abrasive jet cutting is dehumidified and dust-free air, whereas in waterjet cutting, the medium is clean water.
- Pressurized air is delivered using an air compressor in abrasive jet cutting, while in waterjet cutting liquid pump alongside an intensifier is used to deliver pressurized water.
- Air pressure in abrasive jet cutting typically remains within 2-10 bar, whereas in waterjet cutting, water pressure remains at 2500-4000 bar.
- Abrasive jet cutting is unsuitable for food processing given the inherent risk of abrasive contamination. Waterjet cutting, on the other hand, is ideal and hygienic for slicing food items.
Plasma Cutting Vs. Waterjet Cutting
Ordinarily, plasma cutting is quite a popular cutting method for sheet metals but is relatively limited compared to waterjet cutting. Plasma uses a series of gas or consumables to form a plasma arc that corrodes metals along a path. It can quickly cut through particular ferrous and non-ferrous metals hence more limited than waterjet cutting, which can cut through all types of metals.
Plasma introduces a great deal of heat hence limiting its cutting capabilities to specific sheet metals. Waterjet cutting, on the other hand, is a cold cutting process thus can cut any type of sheet metal irrespective of the thickness. Also, plasma cutters tend to emit fumes and gases when cutting materials, thus needing precaution and proper ventilation. On the contrary, waterjet cutting is an eco-friendly and safe process since it hardly emits any gas or fumes during the cutting process.
Waterjet Cutting Vs. Laser Cutting
Ideally, laser cutting and waterjet cutting guarantee more speed and high precision cuts. However, laser cutting is somewhat limited to the specific materials and thickness it can cut, unlike waterjet cutting, which can cut all types of metals. The laser can introduce heat into sheet metal that can easily lead to work hardening and melting material.
Waterjet cutting, on the other hand, is a cold cutting process and thus can never subject the material to possible melting or work hardening. Also, laser cutting is more suitable for cutting sheet metals with thin surfaces, whereas waterjet cutting is ideal for both thin and thick sheet metal materials.
How Waterjet Cutting Technology Works
The working principle of waterjet cutting is quite straightforward and usually involves the following aspects;
1) Water is pressurized using specially designed crankshaft pumps that produce water with immense high pressure. Depending on the specifications of the pump, some can produce a pressure of up to 90,000 psi.
2) The highly pressurized water moves to the cutting head through high-pressure tubing. Water then passes through a hard jewel with a relatively smaller hole than a pinhole, often known as an orifice. As water presses through the orifice, it converts pressure to velocity, which can be up to 2500mph depending on the type of pressure you are using.
3) Waterjet cutters come with a mixing chamber and nozzle located below the orifice in the cutting head assembly. In the mixing chamber, the abrasive media is derived into the water stream. Hence, the abrasive elements cut the material, whereas the water accelerates it to form a fine, sharply defined stream that can cut any type of metal.
Notably, different waterjet cutting machines may operate in different ways. However, the basic working principle of waterjet cutting remains the same.
Factors Affecting Quality Of Waterjet Cutting Metals
Several elements tend to determine the overall quality of waterjet cutting in metals. However, the notable ones include the following;
Ordinarily, nozzle plays an integral role in determining the actual quality of finished waterjet cutting metals. Hence, you need to look into some of its parameters, such as chamfer radius, nozzle diameter, mixing pipe length, and its diameter among others.
Mixing State Of Abrasive
The nature of abrasive you are using in conjunction with pressure water also determines the overall quality. In essence, some metals surfaces are best suited with dry powder, whereas others are ideal with slurry powders.
The notable features of abrasive substance used in this process that determine overall quality include actual abrasive material, flow, diameter, and shape.
In this case, the metal properties such as density, strength, and hardness are among the factors that affect the quality of the process.
Ordinarily, the waterjet system pressure is a considerably finished quality determinant. The higher the pressure, the speedier the process and the better the quality.
Usually, aspects such as feed speed, cutting times, target distance, and jet angle are among the cutting parameters that influence the quality of waterjet cutting metals.
Types Of Waterjet Cutting
It is an interior surface finishing ideal for deburring and honing interior surfaces, which conventional deburring techniques can hardly reach. This method erodes part surface by eliminating unwanted particles as water and abrasive make contact with raised interior workpiece surfaces.
It is a waterjet cutting method that includes a high-pressure water stream with an abrasive. Technically, it blasts and erodes the sheet metal and removes particulate matter, materials and burrs. The particles used in cutting are exceptionally fine and often applied at relatively high velocity. This technique is ideal for cutting and shaping brittle, hard metal materials into intricate shapes to form smooth and even edges.
This process involves using intensifiers to radically increase pure water pressure to enable its shape and create soft materials without leaving water residue. The hydraulic pump intensifies water flow, harnesses water force, and converts it to mechanical energy.
It uses same principles of high-pressure waterjet cutting, only that it is programmed to conduct multiple operations during a single pass. CNC waterjet cutting is mainly used in circumstances where material to be shaped and cut is somewhat sensitive to high-temperature processes. The notable cycles of this process include cutting, forming, deburring, reaming, and honing.
Types Of Waterjet Cuts
These are stationary cuts carried out in a single metal workpiece pass through a waterjet cutting mechanism. They are pretty simple and entail the operator feeding the metal into cutting tool while water and debris are caught in the other section.
Also known as XY, it needs the use of CNC programming and has a servo motor with closed-loop feedback to regulate positioning and cutting velocity. This method is suitable for the rapid cutting of various metal parts.
XYZ, cutting entails use of X-axis, which moves from left to right, Y-axis moving back and forth, and Z-axis moving up and down. The workpiece remains stationary in this three-axis process as the cutting tool moves along the three planes.
XYZA cutting involves processing workpiece by three-axis of XYZ, but a fourth-dimensional rotary motion is included around the X-axis. Cutting along A axis enables the workpiece to be cut along B axis. Ordinarily, the additional A-axis provides an option of flipping the workpiece automatically to allow waterjet to remove material from all sides of a workpiece.
XYZAB cutting allows manipulation of the workpiece on five sides simultaneously. Ideally, the metal workpiece still moves along XYZ axis with additional axis movements performing 180-degree rotations around X, Y, and Z axes.
Applications Of Waterjet Cutting
Waterjet cutting is regarded as the safest and most hygienic method for precision and portion control. It cuts fish, meat, frozen foods, pastries, and poultry into accurate and perfect shapes.
People Also Ask:
Orifice failure – Occasionally, waterjet orifices may break down and disrupt the process hence consuming more time and lost productivity.
Higher investment capital – The initial cost of investing in this technology is quite expensive compared to conventional processes.
Once the process begins, waterjet cutting machine can attain a part tolerance of +/- 0.001” with consistency.
Practically, the ideal upper limit thickness that a waterjet can cut ranges from 2-3 inches. However, cutting steel of more than 3 inches tends to consume more time and is quite cost-effective.
- Making parts for aircraft
- Creating automotive parts and components
- Shaping medicinal devices and components
- Industrial cleaning
- Food processing and portion control
- Making electronic parts and components
It cuts all types of metals, including aluminum, titanium, hardened tool steel, and various exotic metals.
It only allows cutting.