Water Jet Cutting – What Is Water Jet Cutting

What Is Water Jet Cutting? Water Jet Cutting, also known as water jet, is a high-pressure water jet cutting technology. It is a machine that uses high-pressure water to cut. Under the control of the computer, the workpiece can be sculpted at will, and the material texture is less affected. Because of its low cost, easy operation, and high yield rate, water cutting is gradually becoming the mainstream cutting method in industrial cutting technology.

The Classification of water cutting

1. Divided by sand addition: water cutting is divided into two methods: no sand cutting and sand cutting.
2. Divided by equipment: Divided into large water cutting machine, small water cutting machine, three-dimensional water cutting machine, dynamic water cutting machine.
3. Divided by pressure: divided into high pressure type and low pressure type, generally with 100MPa as the limit. Above 100MPa is a high-pressure type, and below 100MPa is a low-pressure type. The ultra-high pressure type is above 200MPa.
4. Divided by technical principles: divided into pre-mixed and post-mixed.
5. Divided into safe cutting: divided into safe cutting and non-safe cutting, the difference is mainly in the water pressure, low pressure water cutting below 100MPa can be applied to special industries such as: hazardous chemicals, petroleum, coal, hazardous materials treatment, etc. aspect

The Features of water cutting

• Numerically controlled forming various complex patterns;
• It is cold cutting and does not produce thermal deformation or thermal effects;
• Environmental protection, no pollution, no toxic gas and dust;
• It can process various high hardness materials, such as glass, ceramics, stainless steel, etc., or relatively soft materials, such as leather, rubber, paper diapers, etc.;
• It is the only method for complex processing of some composite materials and fragile porcelain materials;
• Smooth cut, no slag, no need for secondary processing;
• Drilling, cutting and forming can be completed at one time;
• Low production cost;
• High degree of automation;
• 24 hours of continuous work

The Development Path Of Water Jet Cutting

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Dr. Norman Franz has always been recognized as the father of waterjets. He is the first person to study ultra-high pressure (UHP) waterjet cutting tools. The definition of ultrahigh pressure is higher than 30000 psi. Dr. Franz is a forestry engineer and he wanted to find a new way to cut large tree trunks into wood. In 1950, Franz put a heavy weight on the water column for the first time, forcing the water through a small nozzle. He obtained a brief high-pressure jet (which exceeded the current pressure many times) and was able to cut wood and other materials. His later research involved a more continuous flow of water, but he found it very difficult to obtain continuous high pressure. At the same time, the life of parts is also calculated in minutes, rather than weeks or months.

Dr. Franz has never made a mass-produced wood cutter. But wood cutting is one of the least important applications of UHP technology. But Dr. Franz proved that high-speed convergent water flow has great cutting energy-the application of this energy far exceeds Dr. Franz’s dream. In 1979, Dr. Mohamed Hashish worked in the Flow Research Laboratory and began to study ways to increase waterjet cutting energy in order to cut metals and other hard materials. Dr. Hashish is recognized as the father of sanding waterjets. He invented the method of adding sand to ordinary waterjets. He used garnet (a material commonly used on sandpaper) as the sand material. With this method, the water jet (containing sand) can cut almost any material. In 1980, abrasive waterjets were used for the first time to cut metal, glass and concrete. In 1983, the world’s first commercialized abrasive waterjet cutting system came out and was used to cut automotive glass. The first users of this technology were the aerospace industry. They found that water jets were ideal tools for cutting stainless steel, titanium, high-strength lightweight synthetic materials and carbon fiber composite materials used in military aircraft (already used in civil aircraft). Since then, sanding waterjets have been adopted by many other industries, such as processing plants, stone, ceramic tiles, glass, jet engines, construction, nuclear industry, shipyards, and so on.

The rise of technology

At the end of the 20th century, water cutting technology was introduced to China, and it has experienced nearly 5 years of market application and equipment improvement. It is mainly used in construction ceramics, stone, metal processing, automobile industry, aerospace, military, petrochemical and other industries and has been well developed. .　At the beginning of the 21st century, in response to the related problems in the market application of water cutting technology and the unity of technology, portable water cutting technology came into being.　Portable water cutting technology belongs to low pressure water jet technology, that is, the cutting operation of metal and other materials can be realized by using lower pressure (25 Mpa ~ 50Mpa). The emergence of this technology has strong practical application significance. The birth of portable waterjet technology has opened a historic page for the development of waterjet technology. It is another new breakthrough in the field of waterjet technology, marking that waterjet technology has entered the research stage of portable waterjet technology.　The portable water cutting technology draws on the basic principles of water cutting technology, aside from the post-mixed cutting principle of traditional water cutting technology, and carried out technological reforms and innovations. The technology was mainly used in the destruction and treatment of dangerous goods such as ammunition in the initial stage. With the continuous improvement of portable waterjet technology, its application fields have also been further expanded. It is mainly used in EOD, petrochemical, underground mine operations, engineering construction, and ships. Manufacturing and other related industries.

Technological development

The portable water cutting system is a new type of water cutting equipment, which has the characteristics of small size, light weight, convenient transportation, and high cutting efficiency. It can cut steel plates, ceramics, marbles, cement products, etc. with lower water pressure. Therefore, the portable water cutting system has broad market application prospects, which can meet the different requirements of customers for cutting ability and operating environment.　In the past actual market applications, the portable waterjet cutting system showed excellent results. It is mainly used in the destruction of aerial bombs, petrochemical pipeline cutting, hazardous materials disposal, and cutting of flammable and explosive materials. The application effect is obvious, and the hidden safety hazards can be easily eliminated during the cutting process. It has become the first choice for aerial bomb destruction, petrochemical pipeline cutting, oil tank cutting, and oil tanker drilling.

The Features And Advantages Of Water Jet Cutting

• Wide cutting range: It can cut most materials, such as metal, marble, glass and so on.
• Good cutting quality: smooth incision, will not produce rough, burr edges.
• No heat processing: Because it uses water and abrasive cutting, no heat (or very little heat) is generated during the processing. This effect is very ideal for materials affected by heat. Such as: titanium.
• Environmental protection: This kind of machine uses water and sand to cut, this kind of sand will not produce poisonous gas during the processing process, and it can be discharged directly, which is more environmentally friendly.
• No need to change the cutter: You don’t need to change the cutting machine device, one nozzle can process different types of materials and shapes, saving cost and time.
• Reduce burrs: water jet cutting with abrasive sand, the incision has fewer burrs.
• Fast programming: The program is mainly generated by CAD drawing software. You can design the line drawing in the layout at will, or input the DXF file generated from other software. In addition, the machine supports third-party software, such as nesting software ( It is used to fill up the graphics in the workpiece, which can minimize the loss of the workpiece).
• Fast programming: The program generated by other software can be transferred into the machine, it can establish the tool path from CAD, and can calculate the precise positioning and cutting speed of the cutter head at more than 2000 points/inch (800 points/cm) After that, all you need to do is specify the material and thickness you want to cut, and leave the other work to the machine to complete.
• It can be combined with other equipment and can be operated separately: the water cutting machine can be combined with other processing equipment (such as drilling head) to make full use of its performance and optimize the degree of material utilization.
• Reduce the number of adjustments: the workpiece can be fixed with only a small side pressure, reducing the trouble caused by complex clamping.
• No restriction on cutting direction → Various cutting shapes can be completed.
• The generated horizontal and vertical forces are extremely small → The setting time and the cost of using fixtures can be reduced.
• The drilling and cutting functions can be completed with the same machine → process time and cutting cost can be reduced.
• No thermal effect or deformation or fine cracks → No secondary processing is required, which can save time and manufacturing costs.
• Will not produce toxic gas → It can provide a better working environment for operators.
• No burrs → can shorten the time and cost of workpiece manufacturing.
• Thin cut → can reduce the generation of a large amount of waste materials and save direct manufacturing costs.
• The cutting of the workpiece can be completed at one time and has good trimming quality → It can reduce the process time and cost.
• Flexible adjustments can be made according to different designs and workpiece materials → The time from order acceptance to finished product output can be shortened, productivity can be increased, and more business opportunities can be brought to the enterprise

The Related Questions Of Water Jet Cutting

Due to the effect of energy gradient, the deeper the cutting surface (the farther from the nozzle), the worse the cutting ability of cutting methods such as laser, gas plasma, and jet, so the formed cutting surface is often not perpendicular to the surface of the workpiece, which is called cutting Slope, which is an inherent defect of all cutting methods. Although the cutting slope can be partially reduced by increasing the cutting energy or reducing the cutting speed, there is still the problem of not being able to cut completely vertically. Therefore, the idea of ​​a tiltable cutting head was proposed in 1997, and there are commercial products in the world. This is the most direct and effective way to solve the cutting slope and improve accuracy. The principle is that by adding 2 more rotating axes on the basis of the original three-axis platform, the cutter head can swing in any direction, and using the pre-set slope model in the system, through real-time calculation of the cutting trajectory, and then according to the cut The material and thickness of the workpiece are corrected, and the cutting head is constantly oscillated during the cutting process, so that the cut workpiece reaches a perfect non-slope state.

• Cutting material: Ultra-high pressure waterjet can cut various thick and hard materials: such as stainless steel, aluminum, copper, steel, marble, alloy metal, glass, plastic, ceramics, tiles and various visible materials.
• Cutting accuracy: The accuracy of cutting the workpiece is between 0.1mm and 0.25mm. The accuracy of the workpiece is determined by the accuracy of the machine, the size and thickness of the workpiece to be cut.
• Cutting gap width: it depends on the size of the cutting material and the nozzle used. Generally speaking, the incision of sand cutting is about 1.0mm to 1.2mm. As the diameter of the sand knife tube expands, the incision becomes larger.
• Cutting bevel: The cutting speed of the rotation determines the quality of the bevel. Most of the single-sided bevels with good cutting quality are about 0.1mm.
  Scope of application: Generally speaking, with complex patterns, thick, difficult to cut, fragile and heat-resistant materials, water jet cutting is most suitable for processing equipment