Setup requires the import of a graphic file; the machine generates the marking program.Click image to enlargeShop Metalworking Technology discusses laser marking with Thomas Burdel, national sales manager for TRUMPF Inc., Farmington, CT.

How does laser marking differ from industrial laser cutting?
Laser cutting uses a tremendous amount of power–several thousand watts is not uncommon–to melt a narrow line in sheet steel or aluminum. The molten material is then ejected through the bottom of the kerf using compressed air or gas, separating the finished workpiece from the raw material. With laser marking, you don’t cut through the part, so the power levels are far lower, typically 50 watts or less is sufficient. Both processes may use solid state lasers, but marking generally employs wavelengths of 355,532, or most often 1064 nanometers (ultraviolet and green light) compared to a laser cutter’s 1064 nm infrared wavelength only. Finally, almost all laser markers use pulsed light rather than continuous wave, and are much smaller, stand-alone devices, roughly the size of a shoebox.

What materials can be laser marked?
Simply put, nearly everything. Laser marking works on metal, plastic, silicon, glass, rubber, textiles, and even organic material such as paper and wood. Depending on the amount of power being applied and its duration, it’s possible to remove substantial amounts of material, or touch it only gently enough to change its colour. For example, laser light can be used to bleach or blacken a wide range of polymers. There’s no heat or ink involved, and it’s extremely fast. The colour change is similar to what happens when plastic is left in sunlight for a long period of time, except here it’s instantaneous. Annealing is a similar process, one that is frequently used on metal. The workpiece is heated enough to create a colour change, but there is no material removal, leaving the surface smooth. Apply slightly more power and ablation occurs, which removes a thin top layer of material. This works very well on parts that have been painted or anodized. Engraving removes even more material. By using a high power laser (or moving slowly with a low power one), very deep marks are possible. Some less common processes include foaming, which uses a laser to create small gas bubbles beneath the surface of a plastic workpiece to create a raised mark, and surface conditioning, where marking lasers are used to remove rust and corrosion from various materials.

 

Who uses laser marking, and why?
Anyone that wants to mark something quickly and needs it to be difficult to remove. Compared to inkjet markers, laser marking is far more permanent. Mechanical marking is noisy and limited to metals. Lasers are the perfect tools for marking nearly anything. Many of our systems are used for placing an identification mark–a logo or serial number, for example–on medical components. These might be for pacemakers, or knee and hip implants, and are typically low volume applications, so are done on stand-alone stations. Another medical example is pharmaceuticals, where testing kits or pill bottles are sold to large retail chains and must be marked with a data matrix for traceability. This is a perfect use for laser coloring on an automated packaging line, since it is very fast and has no impact on the base material. Of course, we also provide systems to aerospace and defense companies, consumer products manufacturers, and especially the automotive industry, where cost effective solutions are always an important concern.

 

How much do they cost, and what should I know before buying one?
It all comes down to what you’re marking, and how fast you need to mark it. Laser power is probably the first question. You can engrave most any metal with a very low power laser, but it won’t be very fast. Higher power lasers, however, cost more. For simple applications such as basic marking of metal or plastic, you’re probably looking at $30,000 for a basic system. For those doing special marking, say the UV colour changing mentioned previously, it could get up in the $150,000 range. Integration to a high volume production system may cost substantially more than that. Granted, these are substantial investment amounts, but offsetting that are the very low operating costs down the road, often just a few dollars per hour. As for any application concerns, there really aren’t any. Some aerospace suppliers may be anxious over the heat affected zone (HAZ) associated with laser use, but even deep engraving operations create only a small amount of annealing.

 

Aren’t lasers difficult to operate?
Lasers were once considered “laboratory only” instruments, but that viewpoint has changed considerably over the past 30 to 40 years. Cutting lasers today require some small amount of maintenance and a higher skill level to operate, but laser markers are very simple; they’re almost like using a laser printer. These machines are shipped with predetermined operating parameters for different materials, so setup requires little more than an import of the desired graphic file such as a DXF, JPG, or PDF, and then generate the marking program. It’s very quick. About the only maintenance that’s required is to keep the operating area and the workpieces fairly clean. There’s no motor or moving parts to worry about, and the laser typically has a lifetime of at least 35,000-50,000 hours. Unless there is some accidental physical damage to the lens, there’s really nothing to ever fix.

 

What does the future hold for laser marking technology?
The market is really growing, pretty much across the board. Automotive, medical, electronics–everybody wants their parts marked cleanly and easily. Companies used to get by with labeling their products, but found that counterfeiters were peeling them off and replacing the labels with their own brand name. And the US FDA has some new requirements about unique part identification, where every part in an assembly had to be identified, rather than just the entire part. We have injection moulding companies that serialize their parts as they pop out of the mould. That’s all done with lasers. The market growth is really fueled by two things: the need, some of which I’ve just described, and the fact that lasers are getting smaller, less expensive, and more flexible. Some of the newer systems have adjustable focal points, making it easy to mark multiple levels on a workpiece. And they’re very easy to integrate with other systems. Considering the increased need for traceability, accountability, and foolproof product information, laser marking has a bright future. SMT

 

Uncoiling industry challenges

Addressing the need for faster coil changing times, better quality materials

by Mary Scianna

At its best, coil handling is a challenge for fabricators, whether they’re using coils with roll forming machines,

You Get What You Pay For

When people think about the old adage

2018 SHOP TALK

by Andrew Brooks

Job shops in Canada discuss challenges and successes

Top 10 Biggest Design Errors Engineers & Architects Made

A top ten countdown of bizarre and noteworthy errors made by engineers and architects.

Hypertherm re-launches contest for North American schools

Hypertherm is holding its "Spark Something Great" education grant program again in 2017. The contest is open to Canadian and US schools and 10 North American winners will receive Hypertherm's new Powermax45 XP plasma cutting and gouging system and the company's Plasma Cutting Technology: Theory and Practice curriculum kit.

Large refrigeration manufacturer eyes new Guelph location

An Ontario fridge and freezer manufacturer is considering a new facility in Guelph, Ont. that would employ up to 250 people.

Solid state fiber laser

The TRUMPF TruLaser Tube 7000 fiber solid state laser in action.

Grinder Safety

Walter Surface Technologies presents its range of grinder safety features.

Why graphene hasn’t taken over the world...yet

Graphene is a form of carbon that was supposed to revolutionize materials science, medicine, engineering and more. Why hasn’t it taken over the world?

Montreal show post report: 4000+ attendees

The Montreal Manufacturing Technology Show (MMTS) pulled in more than 4000 manufacturing professionals during the three-day event held May 12-14 at Place Bonaventure in downtown Montreal, QC.

Plasma productivity in Alberta: A Solid Foundation

by Nestor Gula

Alberta screw piles manufacturer spurs growth with new tube and pipe cutting equipment

Natural Talents

by Andrew Brooks

Canada’s strength in natural resources is being matched by its winning hand in renewable energy

Mustang GT contest winner announced

Walter Surface Technologies has announced the grand prize winner of its “Test Drive Flexsteel. Take Home a Mustang GT” contest.

Building Machines In Canada

Canada gets first OEM of oxy, plasma cutting systems

by Mary Scianna

Paul Bhogal thinks we’re selling ourselves short in the manufacturing realm in Canada and that we can compete with the best of the global players.

Stay In Touch

twitter facebook linkedIn