What Are the Different Types of Water Jet Cutting Machines?

Water jet cutting is a plane cutting machine which combines the ultra-high pressure water jet generator and two-dimensional numerical control processing platform. It raises the pressure of the water flow to a sufficiently high level (above 200 MPa), so that the water flow has great kinetic energy, and can penetrate chemical fibers, wood, leather, rubber, etc. When a certain proportion of abrasive is mixed in a high-speed water flow, it can penetrate almost all Hard materials such as ceramic, stone, glass, metal, alloy, etc. Under the guidance of the two-dimensional numerical control processing platform, start processing or end processing at any position of the material, and move at an appropriate speed according to the set trajectory to achieve plane cutting processing of arbitrary graphics.

As an independent and complete processing technology, the production of high-pressure water jets (wj) and abrasive water jets (awj) has been in the last thirty years. The use of high-pressure water to serve people's production began in the 1870s. Right and left, it was used to mine gold ore and to peel bark. Until World War II, the phenomenon of "rain erosion" during aircraft operation destroying the radar cabin inspired people's thinking. Until the 1950s, the possibility of high-pressure water jet cutting originated from the Soviet Union, but the first cutting technology patent was generated in the United States, which was obtained by Dr. Norman Franz, a professor of forest science at the University of Missouri in 1968. In the past ten years, water jet cutting technology and equipment have made great progress, and its application has covered all aspects of industrial production and people's lives. Many companies and factories compete in research and development, and new thinking, new theories, and new technologies continue to emerge, forming a momentum that you can catch up with. At present, many sets of water jet cutting equipment have been applied in dozens of industries, especially in aerospace, ships, military, nuclear energy and other high, sharp and difficult technologies. It can cut more than 500 kinds of materials, and its annual growth rate of equipment exceeds 20%. ^[1]

1. There is no restriction on the cutting direction, and various special-shaped processing can be completed;

2.

1. Can easily cut stainless steel plates or hard marble, granite, etc.

Difficult to cut materials such as aramid, titanium alloy and other composite materials are even more ideal or the only processing means.

2. It does not produce cracks when cutting, it can cut materials with very narrow gaps. Generally speaking, the cut of pure water is about 0.1mm to 1.1mm, and the cut of sand is about 0.8mm to 1.8mm. As the diameter of the inner hole of the sand nozzle increases, the cutout becomes larger.

3 Can be cut in all directions, including various shapes, angles or slopes;

4 No secondary processing such as edging is required, and fly dust can be reduced during cutting to improve work

The form of water cutting is divided from water quality, there are pure water cutting and abrasive cutting; from the pressurization method, there are hydraulic pressure and mechanical pressure; from the machine tool structure, there are gantry structure and cantilever structure.

A complete set of water cutting equipment is composed of ultra-high pressure system, waterjet cutting head device, waterjet cutting platform, CNC controller and CAD / CAM cutting software.

Laser cutting equipment has a large investment. Currently, it is mostly used for cutting thin steel plates and some non-metallic materials. The cutting speed is fast and the precision is high, but laser cutting will cause arc marks at the slit and cause thermal effects. Laser cutting of materials is not ideal, such as non-ferrous metals and alloys such as aluminum and copper, especially for thicker metal plates. The cutting surface is not ideal, and it is impossible to cut. So far, people's research on high-power laser generators is trying to solve the cutting of thick steel plates, but the cost of equipment investment, maintenance and operation consumption is also considerable. Water cutting has small investment, low operating cost, wide range of cutting materials, high efficiency, and convenient operation and maintenance ^[2]

For metal processing, wire cutting has higher accuracy, but the speed is very slow. Sometimes other methods need to be perforated and threaded to cut, and the cutting size is greatly limited. Water cutting can punch and cut any material. , Fast cutting speed, flexible processing size.

Plasma cutting has obvious thermal effects, low accuracy, and it is not easy to perform secondary processing on the cutting surface. Water cutting is cold cutting, no thermal deformation, good cutting surface quality, no secondary processing is needed, and secondary processing is easy if necessary.

Water jet cutting, ultra high pressure water jet cutting machine is to pass ordinary water through an ultra high pressure pressurizer, pressurize the water to 3000bar, and then pass a water nozzle with a diameter of 0.3mm to produce a water jet of about 3 times the speed of sound Under the control of the computer, it can easily cut any graphic soft materials, such as paper, sponge, fiber, etc. If sand is added to increase its cutting force, almost any material can be cut.

Compared with the traditional "hot" cutting process, the ultra-high pressure water jet cutting machine tool uses water flow as the cutting medium, which is a "cold" cutting process. It has the following functions and advantages:

1. No thermal deformation during cutting, avoiding physical and chemical changes of the material;

2. It is widely applicable to the cutting processing of various materials and has the reputation of "universal cutting machine";

3. The incision is smooth and burr free, and generally no further processing is required;

4. Controlled by CNC system, high cutting accuracy;

5. The cutting seam is less than 1.2mm, which is convenient for nest cutting and saves material;

6. The process will not produce waste that pollutes the environment.

CNC waterjet is an ideal or only processing method for materials that are difficult to cut by other methods, such as Kevler, titanium alloys and various composite materials.

Strictly speaking, although CNC waterjets can cut more accurately than flame and plasma cutting machine tools, they are not yet precision machining machines and should not be marked with accuracy. When cutting a sheet below 10mm, the cutting speed and compensation are properly controlled, and the error can be + -0.1mm.

Because the target distance of the water jet is uncertain or changed, the maximum cutting thickness of the CNC waterjet is not well defined. The daring, dare to call 400, 500mm, the conservative said that within 100mm, are reasonable. The existing numerical control waterjet generally has a flow rate of 2 to 3 liters and a working pressure of 200 to 380 MPa. The jet passes through air resistance and the energy decay is extremely fast. When it reaches 400 or 500 mm, it will basically drift with the wind and there will be no impact.

For general applications, it is recommended that the thickness of the cut metal sheet does not exceed 100mm, and the thickness of foamed materials such as sponge is recommended not to exceed 300mm ^[3] .