Water Jet Cutting Machine



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    What is water jet?

    Water jet is generated when water flows from a high pressure pump, through plumbing and out from a jewel nozzle with tiny opening. At approximately 276 MPa (40,000 PSI), the water jet exits out of the jewel orifice at Mach 2 (680 m/s or 2,450 Km/hr) while it is over Mac 3 (1,021 m/s or 3,676 Km/hr) when pressure goes up to 414 MPa (60,000 PSI). This remarkable water jet bears considerable amount of energy which turns into forces for cutting, scoring, trimming, slicing, slitting and cleaning as well.

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    Why is water jet extensively used in numerous industries?

    Water jet cutting systems are the world’s most versatile machine tools. Water jet process is also recognized as the most versatile and fastest growing process in almost all industries. The process provides many unique capabilities and advantages. Waterjet has shown that it can do things that other technologies simply cannot. It is proven to be more beneficial and cost effective than traditional technologies such as, machining, laser, plasma, EDM wire cut, oxy-fuel cut and diamond tool, etc. There are virtually no limits to what water jets are capable of cutting and machining. The machines are extremely easy to use. Operators can handle the machines after few hours training and produce high quality parts in hours. Our water jet system are suitable for production of high volumes, short runs or prototype parts.

    The versatility makes abrasivejets drastically popular in the markets in the last few years. Advance technologies, include control, high pressure pumping, high pressure parts and components, has suddenly made everything possible that could not previously be achieved.

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    How is water jet developed?

    Low pressure water jets were firstly used for gold mining in California, USA in 1852. Steam and hot water jets were used in the early 1900s for cleaning purposes. High pressure water jets were used for mining in the 1960s.

    After numerous trials and errors, in early 1970s, it was discovered that water pressure at between 276 MPa and 414 MPa (40,000 PSI to 60,000 PSI) at approximately 0.1mm water jet stream could neatly cut everything from cardboard to disposable diaper. This revolutionary technology was developed for industrial purposes and was applied in those areas that had been failed to cut with knives or mechanical processes. Water jets were then extensively applied in following applications,

    • Cardboard
    • Disposable diaper
    • Insulating material
    • Foam rubber
    • Gasket material
    • Carpet material for automotive applications
    • Food products
    • Fabric
    • Leather

    These were all soft materials. This was because cutting of hard materials, for example glass, metal, stone and ceramic, was unsatisfactory. Industrialists and scientists continued to investigate.

    In early 1980s, in addition to standard water jets components, special nozzle was developed and little amount of abrasive powder was introduced into the water jet and the abrasive such as garnet, ejected out from the nozzle traveling as fast as the water jet. This, so called “abrasive jets”, was able to cut any hard and tough materials such as titanium, stainless steel, glass and ceramics with satisfactory results.

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    What are applications of water jet?

    Water jet cutting systems are widely used, but not limited to, following industries,

    • Aerospace
    • Architectural and construction
    • Automotive
    • Marine
    • Electrical and electronic
    • Solar
    • Elevators
    • Film
    • Food processing
    • Gasket
    • Glass
    • Carpentry
    • Lighting
    • Sporting goods
    • Medical
    • Communication
    • Machining and tool
    • Education facilities
    • Prototype development
    • Musical instrument
    • Plastic and rubber
    • Chemical
    • Recreational equipment
    • Semiconductor
    • Computer
    • Optics
    • Wood
    • Metal
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    How does water gain enough energy for cutting?

    Water is pumped to high pressure by means of high pressure generators. The pressurized water passes through plumbing tubing running to the end where a jewel is affixed. The jewel has a tiny hole on it. When the pressurized water runs through the tiny opening, the pressure energy is transformed into velocity energy such that the water travels at high speed at the exit of the jewel. This extremely high speed water stream is what we call waterjet. The outstanding velocity of waterjet stores huge amount of energy. When water hits on material, this velocity energy is instantaneously transformed to those energies which are sufficient enough to tears away microscopic pieces or grains of work piece. This supersonic water stream erodes the work piece materials in pure waterjet process.

    However, work piece materials are eroded by abrasive particle, not water stream, in abrasive waterjet process. In abrasive waterjet, the waterjet stream accelerates abrasive particles. These abrasive particles gain huge amount of velocity energy which is sufficient enough to tear away microscopic pieces or grains of work piece and hence, erodes the material. Since abrasive is harder and has higher density than water, so the abrasive’s momentum energy is higher than pure water stream’s, resulting in much powerful eroding capability. The water jet drags the abrasive through workpiece in a curved path and the resulting centrifugal forces press the abrasive against the work piece. The abrasive thus, “grind” the work piece. So the jet cutting action is practically a “grinding” process, but rather than using solid grinding wheel. The forces and motions of the cutting or grinding action is provided by water. Consequently, abrasive waterjet can cut harder and thicker material than pure water jet.

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    What stops the water jet?

    Generally, 900mm of water in the catcher would be good enough to dissipate the energy of the jet

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    Is secondary finish required after water jet cutting?

    When there are no special applications, secondary finishing after water jet cutting is not required. For example, the cutting finish of steel after water jet cutting is as high as Ra3.2. Satin smooth surface or edge finish are obtained in most of the cases.

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    Are there different types of water jet?

    There are two types of waterjets. They are pure waterjet and abrasive waterjet. Each of the processes has its own unique features.

    Pure Waterjet
    Water jet cutting process was firstly launch in the market in the way of pure water jet in middle of 1970s. It was used for the cutting of corrugated cardboard. Then it was widely applied to cut disposable diapers, tissue papers and automotive interiors. This was because less moisture were created on materials during waterjet cutting than touching or breathing on it. Advantages of pure water jet are,

    • Very thin water stream
    • Very little material wastage during cutting
    • No heat is generated during cutting
    • Applicable to both thin and thick materials
    • Fast cutting
    • Extremely low cutting force
    • Very suitable for light and soft materials cutting

    Abrasive Waterjet (Abrasivejet)
    Abrasive waterjet is develop base on pure waterjet system. When abrasive materials, such as garnet, are feed in the cutting head of pure waterjet system, they are mixed together properly with water inside the cutting head, the water-abrasive jet becomes more “sharper” with higher cutting ability. This abrasive characteristic enables the water jet to cut almost any kinds of hard, delicate and thick materials.

    Abrasive water jet can cut as hard as aluminum oxide ceramic or alumina (AD 99.9). Advantages of abrasive waterjet are,

    • Extremely versatile process
    • No heat is generated
    • No mechanical stresses
    • Thin stream
    • Thin and thick material cutting
    • Little cutting material wastage
    • Low cutting force
    • One jet setup is almost applicable for all abrasive jet jobs
    • Quickly switch between abrasive waterjet to pure waterjet
    • Little or almost no burr
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    Why do I need water jet machine?

    Water jet machine is very suitable to cut,

    • Complex outlines and profiles such as figures, patterns, alphabets and symbols, etc.
    • Brittle materials such as glass and ceramic
    • Hard and thick materials
    • Heat sensitive materials
    • Composite materials
    • Any other materials that traditional machines could not achieve or perform satisfactory such as cutting, slitting, slicing and sawing.