Case: Ink jet printing is being used to produce identification markings on the customers Nylon extruded tubing and Nylon coated electrical cable products. They are assessing the improvements they could expect if they were to change to laser marking. The extruded Nylon materials are produced in a variety of different colours including Black, Opaque, Yellow and other colours also. The speed of extruding ranges from 8 – 100 metres per minute, so any potential system needs to be able to mark 'on the fly' at these fast speeds.
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Laser Marking Systems: Test marks were performed on all the materials supplied using a Laservall Violino-II Nd:YVO4 (Vanadate) DPSS laser marking system fitted with a 160mm F-Theta Objective and running on Smartist 4.1.1 software. Test Marks were also produced using a Synrad 25W 10.64um CO2 laser system fitted with a 370mm F-Theta objective, running on WinMark software.
Application Results: The marks performed using a CO2 laser did not give a great contrasting mark. This laser wavelength is readily absorbed by polymer materials and the action of marking on this material created an engraved mark rather than a discoloration that the customer prefers.
Using the 1064nm laser gave a much better level of contrast on both material colours. The mark on the black material was a high contrast sharp white mark, that was highly legible. The mark on the yellow material did not have the same high level of contrast but was neat and legible.
Marking Times: We did establish that the mark produced on the black Nylon material could be marked in times of under 100 milliseconds, which strongly suggests that marking this material 'on the fly' at the speeds required should be possible, though we may suggest stepping up to a slightly higher laser power to reduce the marking times further. The trials strongly indicate that the marking speeds required can be achieved.
Note: When laser marking Nylon material, fumes do evolve that can be harmful. We would recommend that the customer would need to introduce some form of fume extraction to remove these fumes when the materials are marked. We can supply a fume extraction and purification unit as part of the system if required.
June 2010 Laser Marking on Powder Coating, Acrylic and Lacquered Brass
Case:Our customer has been looking at introducing new products that will require marking with identification and compliance information. The parts they are looking to mark are made from materials including Acrylic, Powder Coated Metal and Coloured Lacquer coated brass. We have being asked to mark samples of these parts to establish which laser technology will produce the best quality of mark on these new materials and to establish the likely marking times.
Acylic Part (CO2)
Colour Lacquer (CO2)
Powder coating (1064nm)
Powder Coating (CO2)
Laser Marking Systems: Test marks were performed on all three materials using a Datalogic Violino1064nm Nd:YVO4 (Vanadate) DPSS laser marking system fitted with a 160mm F-Theta Objective and running on Smartist 4.1.1 software.The parts were also marked using a Synrad 10.64um 25W CO2 laser marking system fitted with a FLA200mm F-Theta Silicon Nitride lens and running on Synrad WinMark software.
Application Results:The software was programmed to mark an arc inscription with the marking produced on the curved face at the entry point of the part. The curvature on these faces was relatively small and would not represent a problem to maintain focus on to these faces
Using a 1064nm laser on the Grey Acrylic materials gave marks that were slightly lacking in contrast and using a 10W laser marking times of around 5 - 10 seconds per part were recorded. A number of marking techniques were used to try to optimize the contrast level but we expect the results achieved were not to a suitable quality. Using this laser on the coloured lacquered brass parts we know from previous trials creates a mark on the underlying material with this wavelength passing through the transparent lacquer. The 1064nm wavelength did produce a neat dark mark on the powder coated parts, with samples marked with a 'double line font' that was fast to mark and a 'True Type Font' that was more prominent.
Using the 10.64um CO2 laser gave notably better results on all three materials. The lacquered parts looked exceptionally good, as did the powder coated parts. The Acrylic part created an engraved mark rather than a contrasting mark. This was however very neat and easy to read.
Marking Times: The marks produced on the parts using 1064nm lasers ranged from 4 – 10 seconds; The marks produced on the parts using the 10.64um CO2 laser were all under 2 seconds.
Note: Due to the materials being marked fume extraction was required for marking all three materials, which could all potentially produce harmful fumes during laser marking.
Case: Our customer currently uses an ink printing process to mark information and symbols on to gas cylinders. This information can consist of large symbols and designs along with alphanumeric text and regulatory information, it also requires significant amounts of cleaning, is very time consuming and gives inconsistent results. Following the initial laser marking trials performed on the cylinders, further trials were requested to remove the paint and to see what colour the underlying zinc layer appeared – once all of the paint was removed.
Laser Marked ‘Orange Painted’ Cylinder
Laser Removal of Orange Paint
Laser Marking Systems : The cylinder was laser marked using the same setup as used for the first trials which was a Synrad 48-2 20W 10.6um CO2 Laser Marking System, fitted with a 200mm F-Theta Objective. This lens was used to give extra depth of field to enable us to mark on the curved surface without the need to rotate the cylinder. The marking programme was created using Synrad WinMark software. The Cylinders were located in a basic v-block fixture to ensure that they were stationary during the marking trials performed.
Application Results: Following the feedback from the customer on the first trials we initially attempted to remove the orange paint by using more laser power. This resulted in a black high contrast mark that was much more legible and clear than the first marks produced – with a comparable level of contrast to the white marks presently printed. Further trials marking square shapes enabled us to reveal the underlying colour of the zinc that is used as a protective covering for the cylinder underneath the painted layer. This layer was a dull grey / silver in colour as shown in the second photograph.The tests performed revealed that a black mark could be produced on these cylinders. This is achieved by using a slightly higher power level.
Marking Times:The marks on the orange and blue cylinders were both produced using the same settings, with the laser running at only 50% of its power and with a very fast scan speed. Consequently the marks were produced in 15.7 seconds per mark.
Note: As previously reported it was noted that when the cylinders were marked that some fumes do evolve during marking that may be harmful, so a fume extraction system would be required should the customer look to introduce laser marking. The marking area would need to be enclosed, but a simple enclosure could be designed to suit the customer’s application.
Case: Our customer has a requirement to laser mark an automotive component with a 2D DataMatrix code (encoded with up to 18 characters). The encoded characters do also need to marked next to the code as human readable characters.The part to be marked is die cast Aluminium and may be marked on either a flat pad or longitudinally on the part.
Laser Marking Systems: Test marks were produced using a Datalogic 10W DPSS 1064nm laser marking system, fitted with a 160mm F-Theta objective. The same type of marking could be produced with any of the 1064nm laser marking systems in our range, the different systems power would give faster or slower marking times.
Application Results: The inscription was created using an 8mm square DataMatrix code with the module ratio optimised to give near identical sized black and white cells. The human readable characters were marked as double line characters, at a character height of 3mm. Aluminium cannot be marked to create a black mark due to the properties of the material, the darkest mark that can be achieved is a dark grey colour. The samples supplied marked very well.
Marking Times: The complete inscription was marked in a cycle time of 6.64 seconds. Using a 20W laser would reduce the marking time by around 50%, to get the cycle time below the 5.0 second target time we were given.
