Waterjet technology, when used with an abrasive additive, creates a clean, burr-free cut that does not require secondary finishing and does not leave a heat-affected zone.
A typical water jet system comprises of an intensifier, Cutting heads, 2D cutting machine, and CAD programming centre.
The intensifier produces the 3,800 bar ( 55,000 psi ) high pressure water required for water jet cutting. There are two main methods of producing this high pressure, either by a mechanical pump with a AC motor driving a geared arrangement of pistons or by a hydraulic pump producing 200 bar driving a 20:1 intensifier. Both systems have their merits however the long service intervals offered by hydraulic pumps offset the slight cost increase, as a result we have specified a hydraulic pump supplied by Hypertherm.
The machine is specified with one cutting head and can operate as either a pure water or abrasive cutter.
Pure water cutting
The high pressure water is constricted by an orifice ( typically 0.1mm diameter ) creating a thin beam of water travelling at very high speed and is suitable for cutting most soft materials such as foam, rubber, fibreglass, fabrics etc.
The force of the water cutting light materials may cause them to move slightly also the bubbling back of the water in the tank can cause issues so some clamping the material to the cutting bed will be necessary.
The high pressure water is passed through a diamond orifice ( typically 0.25mm diameter ) into a venturi chamber, the resulting high speed jet of water causes the air pressure in the chamber to be reduced, drawing metered abrasive garnet into the venturi which is then entrained in the water jet stream. This combined water and abrasive jet then passes through a hardened tube, 0.7mm diameter, to stabilise and focus the beam, creating a abrasive jet approximately 0.8mm diameter travelling at high speed (1000km/hour). This stream will cut virtually all materials upto about 100mm thick. The cutting is carried out by the abrasive wearing away the material, the water in this case is acting as a carrier for the abrasive. Materials that can be cut include, metals including aluminium, titanium, armour plating, ceramics, glass, wood, plastics, stone. etc
2D cutting Machine
Techserv manufacture a range of 2d cutting machine from our base in Mirfield West Yorkshire, with over 500 machine installations worldwide, ranging from gas cutting machines to plasma and water jet along with special purpose manufacturing and monitoring equipment. Please see machine details in our quote below.
Typical running costs for a waterjet cutting machine are about £15 per hour.
This includes the following
electricity, 29 kW
water ( about 2 litres/min )
abrasive ( approx 500 g / min, cost £300 tonne )
pump seals ( these last about 500 hours, £120 a set)
diamond orifice ( life of 1000 hours, cost about £1000 )
focusing nozzle ( life of 70 hours, cost £100 )
Quotation to supply an AcuCut water jet machine
The machine to cut an area of 2.4 m x 1.2 m. It is fitted with a Techserv PC based CNC controller. The Hypertherm HyPrecision 30HP water jet cutting system is fitted with one abrasive water cutting head mounted on a motorised lifter.
Cutting width 1200mm
Cutting length 2400mm
Overall width 2800mm
Overall length 3800mm
Speed 15,000 mm / min
The machine runs on precision guide rails, floor mounted to the sides of the catcher tank. The hose/cable supply to the machine is by drag chain conveyor.
The heavy duty mild steel fabricated tank catches the water and is fitted with a cutting frame.
Main and Outboard carriages
These are robust waterjet cut aluminium assembly running on a pair of linear bearings. The Y and YY axis drive motors are fitted to this carriage .
Extruded aluminium box section beam, with two precision guide rails onto which the cutter carriage is mounted. The entire beam assembly is encased in stainless steel covers to protect the moving parts from the ingress of abrasive.
This heavy duty aluminium fabrication is fitted with four linear bearings to create a rigid base to mount the cutting head. The cutter carriage is fitted with a drive motor and gearbox assembly.
The Techserv CNC is a PC based shape cutting controller, particularly suitable for water jet cutting application.
The controller is based on a PC system running Windows 10
The software is designed to be easy to learn and use with many built in features and is operated using a 15” LCD touch screen.
128 Gbyte solid state hard disc.
Start, Stop, Go To and Reverse.
Vector moves and circular interpolation built in
Eight direction Jog.
Graphic display of nest to be cut, with zoom.
Real-time graphics. A cursor and path line change shows progress on job.
Download files from USB memory stick or network.
Touch screen file selection.
Select job preview, intuitive part program display.
Alpha numeric file name capability.
Standard shapes with graphical display.
Row and column nesting.
Common line cutting.
Program rotate, mirror and scale.
Graphical touch screen plate alignment.
Status displays for speed , X & Y position, program name & status and messages.
Auto or manual cutting mode.
Pierce times can be taught via the screen.
Job interrupt and return, permits move off to replace consumables, with return.
Full reverse along cut.
Off path lead in allows easy restart anywhere along the program.
Test run facility with joy stick repositioning.
Feed rate override 5 – 200% of set speed.
Sealed motor mounted encoders with 2500 lines per revolution.
Three axis brushless drives with rack and pinion drive in all three axis.
This is an electrically operated unit, controlled from the operators panel.
The moving parts are protected by bellows.
Hypertherm HyPrecision 30 hp intensifier
The system has a 4,000 bar ( 55,000 psi ) 30hp intensifier that operates at a working pressure of 3,800 bar. This PLC controlled intensifier has a variable displacement, pressure compensated hydraulic pump. The HyPrecision pump also comes with a cartridge type hydraulic seal for easier maintenance.
A pressure compensated hydraulic radial piston pump is powered by a 22kW, 3 phase electrical motor.
To compensate for the slight pressure drop while the system is switching, the system has an integrated accumulator with a capacity of 2 litres to reduce the pressure fluctuations of the intensifier.
A hydraulically operated safety valve is installed within the high-pressure water system This is opened to release the “high pressure” water in the event of the intensifier being switched off.
The complete intensifier is fitted to a integrated powder coated sheet metal cabinet, with separated catcher trays for the water and hydraulics. It is fitted with removable panels for easy access for maintenance.
Max working pressure 4000 bar
Max continuous pressure 3600 bar
Intensifier ratio 20:1
Max oil pressure 200bar
Require inlet pressure 6-7bar