General Questions
Cutting Costs
Safety
Enviromental issues |
| GENERAL QUESTIONS |
| Perché dovrei utilizzare il taglio ad acqua rispetto al laser ? |
| |
Laser is an high productive cutting system but water jet has many advantages over laser:
- No thickness limits
- No mechanics and heat change
- No material limits
- Maximum manufacturing and application flexibility (starting from rubber to titanium , from sponge to ceramic, from polystyrene to stone metal 60 Roc, from glass to stones, from gasket to the composites)
- No environmental problem (no smog and pollution) because is a clean technology that use just ecological abrasive and water
- Low manufacturing process cost
- High performances
- Minimum hole diamater from 0.1 (0,004” water only) and 1 mm (0,040”) hydro-abrasive
- Accuracy from 0.05 – 0.15 mm. (0,002” – 0,006”)
- No holding devices request for many applications
- Multiple synchronized heads usage to increase production
- Easy maintenance directly on end user's site
- Relevant saving
|
| ..... respect milling?
|
| |
There is no piece holding process and it performs a through-cutting, so it is possible to realize any kind of shape with a single cut, either internal or external, without moving the piece, and with no further operations. |
| ..... respect plasma or oxycut ?
|
| |
Plasma or Oxycut are hot processes, that causes thermal material deformation, creating an heat-affected zone. Using a water jet cutting the result is a cold, clear and sharp-cut breaking on the material.
The water-abrasive cutting has also no thickness limits because it uses a 1 mm (0,040”) cutting tools (jet diameter). It optimizes the material reducing the scrape.
|
|
….. respect wire (EDM)? |
| |
EDM is extremely precise, but very slow: using the new I.T.C. technology (Intelligent Tapering Control) it is possible to create parts with an accuracy near to the EDM ones, but with a 50-80% reduction of time and cost |
What is the maximum thickness able to cut ? |
| |
Up to 150 mm(6”)
We have been able to cut up to 300 mm (12”) in a lab environment.
However good results will be achievable by applications in the 5-50 mm (1/2” – 2”) thickness range. |
|
Which accuracy can we obtain with waterjet cutting? |
| |
The majority of the users are expecting a tolerance of ± 0.1 mm (± 0.004”): if you need this range to be reduced, you should choose the new advanced I.T.C. control system. |
Which is the better performance pressure? |
| |
Using just a water jet, the cutting thickness starts from 0.1mm (0,004”), instead with the hydro-abrasive one it starts from 0.5 to 1.5 mm (0,020” – 0,060”), because the water jet becomes the transport vehicle of the abrasive tool that will be mixed and ejected from a focusing tube with a diameter 3 times the orifice's one |
What taper does Waterjet cutting generate? |
| |
In a standard working process through a water jet cutting the taper depend by a cutting speed; more speed more taper because the jet closed down on the thickness increasing the taper from a minimum of 0, 1 mm (0,004”) up to 0,4 mm (0,016”) for each side of the cut; this means that the bottom parts will be bigger respect the top one. By the I.T.C. (Intelligent Tapering Control ™ ) system is possibile to control the taper compensating by a 4 axis inclination system |
How much water does the process consumes ? |
| |
The water consumption is related to the orifice diameter and it is directly related to the power of the intensifier pump.
0,25 mm = 0,010' orifice uses 1.9 lt/min = 0,6 GPM
0,35 mm = 0,014” orifice uses 3.63 lt/min = 0,9 GPM
0,381 mm = 0,015” orifice uses 4.1 lt/min = 1 GPM
0,40 mm = 0,016” orifice uses 4.69 lt/min = 1,2 GPM |
Why is it better to cut underwater? |
| |
The underwater cutting allows to reduce the noise of the process under 75 dB but you can't see the process: by the optional automatic submerged cutting device it is easy to control and change the level in a few seconds in order to check the quality of the process |
Which is the time frame for the standard maintenance ? |
| |
The high pressure pump seals will need to be replaced after 400 to 1000 hours
The ceramic carbide focusing tube must be replaced after 80 to 120 hours of usage
The diamond orifice will be replaced after 500 to 1000 hours of usage, while the ruby or sapphire one will last 60 to 100 hours |
|
What kind of abrasive is suitable to use? |
| |
The most common is the Garnet one (see Abrajet ™ ) and it is the best in terms of performances, components duration, manufacturing costs, and environmental impact.
80 Mesh is the most common grain with 7,5 Mohs scale: we use 120 Mesh to increase the cutting quality; for special applications we use the 180 up to 220 Mesh to cancel the burrs on a very small thickness or for ultra small piercing (0.5 mm = 0,020”) on hard materials
Olivine is not used anymore because of the lower hardness (5 Mohs scale) and lower performance. |
|
How much abrasive consume ? |
| |
The abrasive consumption depends on the pump range but overall on the orifice diameter and its focusing tube which will be utilized for cutting ( Ø Foc. = 3 x Ø Orif.)
- Øo 0,25 mm (0,010“) / Øf 0,76 mm (0,030“) = 300 gr/min (0,7 lb/min)
- Øo 0,38 mm (0,015“) / Øf 1,02 mm (0,040“) = 450 gr/min (1 lb/min)
|
|
How long the grids will last ? |
| |
The support grids will last for hundreds of hours before it will be completely destroyed. The grids are all same and they can be interchanged, reversed and moved to extend the total supporting table life. |
How is the pre-drill hole executed? |
| |
The water jet automatically pierces all materials of all the thickness, with a diameter ranging from 1mm to 2mm (0.040” – 0.080”), and pressure can be managed in case of soft materials. If the materials are composite, an automatic pre-piercing mechanical device pneumatically controlled is required to avoid the delamination during the piercing process. |
Are Water jet machines easy to use and manage ? |
| |
The water jet cutting system is basically an easy system that, thanks to the CNC automatic control can transform a design made by a WaterCad-Cam Ô software into a finished part
This software is compatible with other Cad software through DXF and has all the technological parameters so you can create a customized cutting program with just a click, completely optimized by an automatic nesting. |
 |
| COSTS |
How much cost the water jet cutting? |
| |
The cutting price basically includes 5 cost elements for about 12 Euro/hour value : (not included manpower, depreciation and disposal costs)
Electric Power (depending on pump power)
Garnet Abrasive (depending of the world location)
Focusing Tube
Diamond Orifice
Pump Maintenance
This cost can differ from country to country due to the different cost of the electric power and the transport of the abrasive |
How much is the sell price for Water jet cutting? |
| |
The job shop cutting centers sell the hydro-abrasive cutting at about 80 to 150 Euro, depending on the application . |
 |
| SAFETY ISSUES |
|
What happens if you put your hand in the direction of the jet? |
| |
It will get cut.
However the water jet cutting system is one of the most safe technologies because, during the working process, a protective covering is mounted surrounding the cutting zone and the water jet distance from the worked material is about 1-2mm. (0,040” – 0,080”) |
|
How noisy is it? |
| |
The noise depends on the gap between the nozzle and the material: If you are cutting underwater the noise level will be less than 75 dB, while if you are cutting above the water level it will increase up to 85-95 dB. |
 |
| ENVIRONMENTAL CONCERNS |
|
Where we can dispose of water/garnet abrasive? |
| |
Neither water nor garnet abrasive are toxic, they are ecological.
The water, when properly filtered, can be put down the drain, while the abrasive must be dumped with not toxic materials.
Instead, if you are cutting toxic materials (as steel) it is mandatory to dump it in an a special areas. |
|
Which water is used for cutting ? |
| |
The softened drinkable water filtered up to a 1 micron is perfect: further clean through an INVERSE OSMOSIS is not needed, because the water will become too aggressive |
|
It is possible to recycle the water? |
| |
Closed-loop recycling systems are available. However, because waterjet systems use a low amount of water, these kinds of installations are not convenient . |
 |
| |
|