Waterjet is one of the most versatile cutting processes around. Well suited for high-performance cutting of metals, ceramics, plastics and most other materials, water jet technology, when used with an abrasive additive, creates a clean cut that does not require secondary finishing, other than removing a slight burr on some soft materials and does not leave a heat-affected zone.
A typical water jet system comprises of an intensifier, Cutting head(s), 2D cutting machine, and CAD programming centre.
Techserv manufacture a wide range of waterjet cutting machines from the Protojet, with its fully enclosed 900 mm x 900 mm cutting area, ideal for education and prototyping. Through to the heavy duty Accucut with a cutting area of 2 m x 6 m and multiple cutting heads.
We also manufacture multi process waterjet and plasma cutters featuring automatic process switching and offset control.
Intensifier
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 KMT.
Cutting heads
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.
Abrasive Cutting
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 700 machine installations worldwide, ranging from gas cutting machines to plasma and water jet along with special purpose manufacturing and monitoring equipment.
Running costs
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 )