WHILE the engraving of rubber stamp dies is a relatively new technology, it is now a popular method of increasing laser productivity.
A number of dedicated stamp manufacturers have also installed CO2 laser engraving machines to make rubber stamps exclusively.
The traditional raw rubber used for vulcanising stamp dies is quite unacceptable for the production of laser stamp dies, as the laser process requires a very even thickness and blemish free surface to produce an acceptable printed image from a stamp die.
The rubber must also be subjected to a specific curing process before it can be exposed to the elevated temperature of a laser beam.
The depth of the engraving is determined by the laser speed, its wattage and the density of the rubber. For example, a 50 or 100W engraver will engrave the rubber deeper and faster than a 25W machine, which may require a second pass to achieve a similar result.
Usually supplied in an A4 size sheet form, a good quality laser rubber is mandatory for engraving stamp dies and must also have suitable compression strength and ink transfer properties.
To assist the engraving process, it is necessary to remove the excess dust which is constantly created by the laser cutting action with an efficient exhaust filtration system.
As very few, if any, CO2 laser engraving machines were initially purpose-built for engraving and cutting rubber, installing and maintaining an effective dust extraction system pays long term dividends.
Mirrors, lenses and any exposed bearing surfaces should be cleaned thoroughly as part of a regular maintenance program. Any neglect in this area will be detrimental to overall trouble free laser operation, as the build up of dust and residue will effect running efficiency and the quality of the finished stamp die.
Many stamp manufacturers use "Coral Draw" as a general purpose software package to create the art work necessary to engrave stamp dies. This program is compatible with most laser software drivers. There are also other rubber stamp software programs designed for specific makes of CO2 laser engravers.
Melbourne based Astron Industries supplies rubber stamp manufacturers throughout Australia and the Pacific area with high quality laser rubber and stamp mounts, and is happy to provide any advice, product, or technical assistance.