HPC LASER
Laser Engraving Options
Engraving
In recent years the subject of engraving has witnessed the migration of many industries away from the traditional methods of rotating cutters , chemical etching and many other established means of permanently marking components . One of the causes of this migration is the way in which more advanced methods have become much more affordable and therefore accessible to a much wider audience .
CO2 Laser Engraving
The most accessible and affordable means of laser engraving is with a CO2 laser source .
Typically based around a water-cooled glass tube and machine bed sizes from A4 upwards , CO2 machines will usually cut non-metals as well as engrave them and offer impressive results on plastics , woods and leather . They also produce fine results on coated metals such as anodised aluminium and power coated steel . However , they are unable to engrave onto uncoated metals without first applying an aerosol or brush applied ceramic marking compound .
Available in several colours , once dried the compound can be burnt into the surface of the material using a CO2 laser . The excess compound is simply washed away to produce an impressive contrasting finish , particularly on shiny metals such as stainless steel and brass .
Because of their relatively large bed sizes , CO2 engraving and cutting machines are well suited to engraving large numbers of small components using a located jig arrangement . Because of the machines cutting capability it can even manufacture its own jig !
HPC recommend that for CO2 engraving , a maximum laser tube power of 80W is chosen which offers a typical working life of around 3,000 hours . Larger tubes can prove difficult to control when engraving intricate designs and some of the detail may be lost . This traditional method of CO2 engraving involves the laser head repeatedly moving left to right whilst indexing forward with each pass , much like an inkjet printer . Whilst extremely accurate and well suited to large batch runs it is a time-consuming process .
Galvo Laser Heads
The next generation of CO2 laser engraving machines utilise a “ Galvo ” static laser head fitted with a series of dynamic internal mirrors that direct the laser beam with incredible accuracy and precision . The machine typically utilises a conventional 60W or 80W water cooled CO2 tube and so will not engrave onto uncoated metals unless the ceramic marking compound is applied first and allowed to dry .
... continued on page 8
6 APRIL 2021 twitter / facebook / instagram : @ trophexlive