Learn how to laser engrave a range of glass objects, such as bottles, mugs, glasses, vases, and plates. You are able to achieve a high degree of detail, regardless of whether your workpiece is flat or curved.
Using a C02 laser system, you can engrave a wide range of flat glass workpieces, such as plates, windows, and mirrors. However, with the use of a rotary attachment, you can also obtain high-quality engravings on round or conical objects, such as wine bottles, champagne flutes, water glasses, beer mugs, and vases.
Hand-blown or crystal glasses may fracture during laser processing due to stresses developed during the manufacturing process. Stress because a glass cools unevenly, as its exterior cools more quickly than its interior. Cast glasses, on the other hand, are well suited to laser engraving as they tend to have a relatively homogeneous structure. Commercial glassmakers use a process called "annealing" to minimize the impact of stress on their products. Typically, glasses will be heated in kilns and gradually cooled.
Mirror glass can also be processed using a fibre laser system. The laser will remove the reflective substrate on the back of a mirror, leaving the glass surface without any engravings.
The Trotec Speedy flexx contains both CO2 and fibre laser sources. Thus, using a single laser system, you can achieve different engravings on a large variety of glass workpieces.
When laser processing glass, rough engravings may be formed due to the interaction of the laser beam heat with the glass surface. The following are a few commonly used methods to prevent rough engravings:
Moist Paper Towel
White engravings are achieved with the use of a moist paper towel.
Prior to engraving your workpiece, apply a moist single-layer paper towel to the glass. Ensure that there are no air bubbles or overlaps, which would negatively impact the engraving quality. Turn the Air Assist function off to avoid drying the paper towel while the object is being engraved. When the workpiece is complete, you can wipe away residual paper towel pieces with a damp cloth
The use of application tape results in grey-coloured engravings.
As with the paper towel method, make sure that no air bubbles and overlaps are formed. Pieces of tape or adhesive that remain after processing can be removed with a damp cloth.
Engraving Without Supplementary Materials
The impact of the laser beam's heat on your glass workpiece can be reduced by configuting the design's colour in your graphics software or on JobControl®.
In your graphics software file, change the design's colour from 100% black to 70% grey before sending it to JobControl®.
In the JobControl® Print window, select the OrderedDithering option from the Halftone menu. Keep the same processing parameters for all other settings.
Glass workpieces with handles (e.g., coffee mugs) can also be processed using a rotary attachment. However, the object must be properly positioned so that the handle is not rotated into the engraving field. Ensure that the circumerence of the object is large enough for the size of the graphic. Otherwise, the design will be engraved on the handle. You can easily inspect the job preview in JobControl® by using the “What you see is what you get” (WYSIWYG) feature.
To prepare your workpiece for engraving, move the Y axis (rotary motion) to the very top, and clamp the object so that the handle is slightly above the laser beam. Since the workpiece is rotated backwards for the laser process, there is no risk of collision with the laser head. For safety, detach the nozzle in order to avoid collision with the rotary engraving attachment. Then focus onto the engraving area of the workpiece.
You can view the exact position of your design in JobControl® by using the “What you see is what you get” (WYSIWYG) or crosshairs features.
If you are using the crosshairs, simply move the Y axis into the desired position. Then place the job on the plate on the crosshairs. By moving the Y axis again, you can review the job dimensions and make any necessary corrections
Select the Minimize to Job Size option in the JobControl® Print window to more easily position the graphic on your workpiece.
Use 70% power (derived from your grayscale matrix) to achieve enhanced results when engraving glass. The lower amount of heat applied to the surface of the glass will create a finer engraving.
With regards to image specifications and JobControl® settings, we recommend using a resolution of 500 dpi and selecting the Ordered Dithering option in your Print settings.
Our technical support specialists would be glad to assist you with any glass engraving questions.