When it comes to laser engraving, it is not all about captivating images and unique designs. Engravers need to be smart about what materials they are engraving on. This knowledge will help save money in the long run by eliminating unnecessary and costly mistakes.
One common practice among engravers is testing the material he or she will be working with before doing any large or costly runs. Especially in cases where a piece is uniquely shaped, one-of-a-kind, an expensive material or possesses a high arch or curve, testing will help ensure you don’t end up replacing a costly item that didn’t engrave the way you anticipated.
Some factors to consider when conducting a materials test include machine cleaning, beam alignment and resolution (generally speaking, higher resolution engraves turn out better, but there are some applications – such as direct fabric engraving – where a lower DPI produces better results). In addition, aspects that should be analyzed when testing a material are feasibility, processing speed, engraving or cutting quality.
Organic vs. Metallic Materials
According to Peck Sidara, Epilog Laser’s applications lab specialist, it is important to first identify the material type you will be engraving: is it metal or organic? If you are working with metal, you will likely want to consider a fiber laser. If you’re engraving or cutting wood, acrylic, leather, cork or other organic material, a CO2 laser should suffice. Also, if you are working with metal, consider whether the metal is bare or treated. Bare metals are better suited for marking with a fiber laser systems (they require no pre-treatment or metal coating), whereas treated metals, such as anodized aluminum or painted brass, often work with CO₂.
There are certain systems on the market that have been designed specifically for metals. When you set out to test materials, make sure you have the right equipment.
Another consideration is whether you need to cut or engrave the material, or both. You will need this information because certain systems cannot cut through metal, so if this is necessary, you would need to find a manufacturer who produces this type of equipment. For engraving and cutting organic materials, a CO₂ system will work for your applications.
If you are new to glass etching, you should test speed and power settings on the glass you are planning to use before starting the actual etching. It is always ideal to have a few extra pieces in case you encounter any problems. If you are concerned about artwork placement on the glass, you can always mask with tape and very lightly engrave your design; in such a testing application, the graphic appears on the tape so you know exactly where it will appear when you engrave the glass.
Thin sheets of polycarbonate can be cut with a system such as Epilog’s CO₂ laser, but the material tends to discolor when heated by the laser beam. A good rule of thumb: the thinner the sheet, the better the cutting results. When it comes to engraving, most colored polycarbonates can be marked with a system like Epilog’s FiberMark metal and plastic marking system.
Recruiting Epilog’s Expertise
If you already have the material you want to engrave (or cut), but have not nailed down the laser equipment to complete your project, Epilog has an in-house applications lab that will help you determine if its lasers are the right tools for your application. The experts send back an extensive report with your parts that discusses the techniques they used to mark them, along with their machine recommendation and other valuable details. All you will need to get started is a brief description of shape, size and location of mark. Graphics or logos are welcome, as long as they are high resolution.
Materials to Avoid
Most materials are relatively laser friendly. While not all materials produce the same depth or contrast with the laser, they are generally safe to engrave. Polyvinyl chloride is one exception to this rule as, when laser engraved, it can be harmful to both your machine and your laser operator. Engraving and cutting these materials can cause irreversible damage, so determining the components of your cutting and engraving materials is extremely important.
That’s where material data safety sheets (MSDS) come in handy – they are a great resource for laser engravers. These documents list the substances used to make up the material and will indicate whether or not it contains components that are potentially harmful to your engraving system—or to those in the immediate vicinity. To protect your health and the life of your machine, always obtain the MSDS for materials if you are uncertain of exactly what is in your engraving material.
What Happens if You Engrave or Cut Something Containing Hydrogen or Vinyl Chloride?
If you do not know what is in the material you are engraving or cutting, you leave yourself susceptible to unintentionally cutting or engraving items that contain polyvinyl chloride. If this happens once or twice, it will likely not drastically damage the machine, but continued engraving or cutting of this material will eventually corrode its components.
More importantly, these materials emit potentially hazardous fumes. Some materials are quite toxic when burned. Preventing damage to your health is more important than any damage your machine will endure. Keeping yourself safe should come first.
Unsure how your material will laser engrave?
If you are interested in Epilog Laser performing the materials testing for you, it is suggested you do your research beforehand. For example, watch some videos of the company’s lasers and how they work. If your piece size exceeds any of the table sizes available, a large-format system may be a more ideal choice. If you need to cut entirely through metal sheets, a higher-wattage laser may be your best bet. To help move the process along, be sure to order some scrap or test pieces of the material you will be working with the most. While the company probably won’t test every single material out there, it will be sure to accommodate all of the testing at once, so gather everything before starting. In addition, prepare your files. Have the files of the pieces or shapes you will want to cut, or if you are engraving, send over the logo or graphic you would want to try out.
Whether you do it yourself or recruit the help of the applications lab, testing is a valuable practice for you to implement during the course of your creativity.