What is high-pressure water jet?

The technology for cutting various materials using water jet or abrasivejet was developed at the end of the 1970s and beginning of the 1980s by the firm FLOW INTERNATIONAL (USA), mostly in the beginning for use in the military and aeronautics program. By the mid-1980s it was already widely used in America and later in countries of Western Europe. Today it has expanded worldwide to include all areas of industry.

The basis for each cutting system is a high-pressure pump that, with the use of a multiplicator, generates water pressure today of more than 400 Mpa (4000 Bar). In industry expirience, currently are being tested a machines with water pressure of 6000 Bar, even more. But this machines are compensated by lower lifetime of their many components. The highly pressurized water is led to the cutting head, where the "cutting tool" is created by a system of nozzles. It can be an approx. 0.15-0.30 mm wide water jet able to cut softer materials such as plastics, wood, rubber, cork, sealants, foodstuffs, etc. The other option most often used is an approx. 0.8-1.5 mm wide abrasivejet with an abrasive powder added (usually garnet "sand"). Thanks to its high energy, the abrasivejet is able to cut metals, stone, glass and other materials at a thickness of 100 mm or more.

We work with the modern technology of leading worldwide manufacturer FLOW International and czech manufacturer PTV.

Cutting machine FLOW

New cutting system PTV

The heart of water jet technology- the high pressure pump

High-pressure pump for the new cutting system PTV

Advantages and disadvantages of technology

Advantages

• Cutting takes place without using a heat medium (max. temperature approx. 40-50°C), thus the material shows no physical, chemical or mechanical changes and it's easy to machine afterwards. The work piece is not deformed by heat (deformation due to internal stress in the material cannot be excluded)
• For materials with a higher thickness, pieces can be put close to one another, which often saves on the material; it is even possible to use a so-called combined cut
• All materials can be cut, including metals and alloys, hardened or otherwise treated, as well as materials that are hard to work, such as fiberglass, glass, rubber textiles, soft and hard rubber, plastics, sealants etc.
• Not even surface treatments are a factor for cutting - polishing, grinding, komaxit ...
• The type of operation can be replaced (cutting, drilling, milling...) with one technological process
• The quality of the cut can be selected, from the best with a roughness of an Ra under 3.2 up to rough cuts that are significantly ribbed, with a significant change in price
• For higher quality of cuts there is usually no need for further machining
• The form of the cut is limited only by the circular cross-section of the jet; cutting very fine contours is also possible
• Mosaics and inlays can be created from all types of different materials (e.g., metals to stone or tile, glass to plastics or wood….
• No noxious fumes are created during the cut, so it involves a technology that is environmentally friendly

• The unavoidable contact with water and often with an abrasive material (without proper and immediate handling surface corrosion occurs quickly, moisture-absorbent materials require longer drainage, changes in color can occur, contamination, etc.)
• These limitations affect many small pieces (under approx. 3-5 cm) - this can possibly be solved with bridgework
• Lower qualities of cuts on stronger materials leads to a deformation of the contour of the cut on the bottom edge due to so-called drifts of the jet

Foraminiferous semi-finished steel products, thickness 60mm

Efective water-jet cutting by two heads ...

Use of bridgework for cutting small pieces from 9 mm stainless steel

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