Written by Techni’s Service Staff
Check the abrasive flow rate is not too high for low pressure piercing.
An efficient cutting head can have a maximum of 0.5 lb/min (225 grams/min).
If the cutting head is not operating efficiently then this amount will be reduced.
The low pressure setting on the ESP should not be any lower than 12 000 psi.
To check your head is not receiving too much garnet, go into the jog window (F3) and select cut job at low pressure while the pump is running.
Select Waterjet On and adjust the garnet flow so that you do not produce a build up of garnet at the end of the garnet feed tube, as it goes into the cutting head. Ensure the garnet feed tube is completely dry before inserting it as far as it can go into the cutting head after a blockage.
Spread support bars (slats) as far apart as possible (support bars must have protective rubber strips on them). Try and position the slats so that you are not cutting along their length. Raise the tank water level to the underside of the glass.
These measures will minimize any ‘splash back’ on the underside of the glass.
Run the machine at the lowest pressure to achieve your production requirements.
By reducing the pressure down to 35,000 psi you will reduce damage due to ‘splashback’ or cracking at the edge of the sheet.
You will also increase the life of all your high pressure components. The down side is that your cutting speeds will also decrease.
Use long lead-ins instead of low pressure. To save time and reduce load on your machine, where possible you can use a long lead in (15mm or more), therefore if any shelling occurs it will be on the waste piece.
Set the Abrasive on delay in your system preferences to ‘zero’ and the Abrasive off delay to ‘0.2’ to reduce cracking when piercing.
A small amount of abrasive should be in the cutting head when starting to pierce.
If the head has been pulled apart, it will need to be turned on manually to prime the cutting head with abrasive.
If the cutting nozzle is turned on with no abrasive in the cutting head and feed tube the first fraction of a second will pierce with water only resulting in cracking or shelling the of the glass.
Avoid using the feed rate override in the cutting window when low pressure piercing.