Loading the player ...
As some shops have already discovered, femtosecond laser technology represents a new frontier in moldmaking. The aim of this new laser is not to replace traditional machining methods; instead, it complements them in a way that ultimately leads to increased productivity for mold shops and manufacturers alike.
Femtosecond lasers are, as the name implies, lasers with pulse durations in the femtosecond range (one quadrillionth of a second), a pulse length that puts these lasers in the category of ultrashort pulses. One prominent advantage of this extremely short pulse length is the reduction of heat absorption, a quality that made femtosecond lasers useful for medical applications, particularly ophthalmological procedures such as LASIK.
Featured Content
MMT Chats: How to Improve Efficiency in 3 Key Toolroom Areas
MMT Chats
Growing AM's Presence in Moldmaking
Naturally, the avoidance of heat transference and a high degree of precision make femtosecond lasers excellent tools for mold production. The ultra-short pulse duration of the laser prevents materials from reentering a fusion state resulting in true ablation while engraving is ongoing. The ablation process vaporizes the material, eliminates burr formation and provides an exceptional level of finish. While nanosecond lasers produce sufficient heat to harden the surface of materials and damage coatings, femtosecond lasers avoid these issues, making them ideal tools for heat-sensitive parts.
Today, the market offers a femtosecond laser machine with a working distance configurable from 73-300 mm, which makes for close work for traditional machining but incredibly generous for laser texturing and other moldmaking applications.
Laser-Focused on Working Distance
Unlike die-sinking EDM or conventional micromachining, laser micromachining has relatively few requirements. The first is simple line-of-sight, a far less restrictive requirement than one finds with other machining operations. As a non-contact tool, lasers can reach places otherwise impossible even with the smallest of diameter spindles and can create small mold features at working distances often unobtainable with ram EDM.
The second laser requirement involves working distance. Because lasers use amplified light as the cutting tool, they rely on lenses and their corresponding focal distances to the workpiece. Many of the ultrashort pulse laser options for micromachining on the market have a working distance of only a few millimeters owing to a working spot size just 1-3 microns in diameter. This allows for amazing detail when hole drilling, cutting or creating micro-structures on flat or tubular surfaces but constrains the laser movement to third or fourth axes, ultimately limiting their capabilities.
Today, the market offers a femtosecond laser machine with a working distance configurable from 73-300 mm, which makes for close work for traditional machining but incredibly generous for laser texturing and other moldmaking applications.
At these distances, laser pulse spot sizes range from 18-70 microns at full power, depending on the lens option, but refined parameters can yield spot sizes in the single-digit microns. These lasers also excel in terms of angles of attack, with full five-axis movement and high-quality cuts remaining possible at up to 70-degree angles.
Unlike the speeds and feeds one considers in milling and turning, the primary parameters used in laser operations involve the laser’s power output, its frequency and the speed of the galvo mirrors that control the laser’s movement across the workpiece.
Manipulating Laser Parameters
Laser ablation, whether used for engraving, texturing or machining part features in molds, requires a different approach to traditional material removal operations. Unlike the speeds and feeds one considers in milling and turning, the primary parameters used in laser operations involve the laser’s power output, its frequency and the speed of the galvo mirrors that control the laser’s movement across the workpiece.
Generally speaking, power is the most straightforward of these factors. If you set the laser’s power to 20 percent, in most cases, you get an output of 20 percent. Modifying the laser’s frequency, the oscillation of the laser’s energy controlling wavelength has a more complex relationship with depth of cut and detail.
To understand frequency, imagine ocean waves. Large waves have loads of power (energy) but occur less often, whereas you could see dozens of small, less powerful waves in the same period. So, low frequencies can remove material fast and aggressively, and higher frequencies will often create higher quality cuts with a slower material removal rate.
Similarly, there is a correlation with the speed of the galvo mirrors movement across the material surface, affecting both removal rate and surface quality. By managing these key factors, operators can vary the depths-of-cut per slice and impact the quality of the ablated surface significantly.
Smithfield, Rhode Island-based Providence Texture is one shop that mastered the manipulation of laser parameters and has already begun taking femtosecond laser technology used to the next level with its machine for micromachining part features. The shop produces a vast range of textures, including those with extremely low Ra-value surface finishes, and generates numerous laser-only textures and patterns.
Many of these part features are deceptively simple, such as a V-shaped groove to add additional pressure to a gasket seal that may be as little as 0.005 inches deep, or one to two-millimeter thread features on a plastic syringe barrel mold. Both femtosecond and nanosecond lasers can create these features faster and more economically than typical die-sinking operations. Furthermore, femtosecond lasers can create micron-level features that demand tolerance ranges too difficult or even impossible with traditional techniques.
Providence Texture has also found that a strategic key to achieving the highest levels of part precision and laser machine production is automation. With its palletized automation system and custom fixturing designed around the laser’s capabilities, the shop keeps its repeatability within ±3 microns. Automation also makes it possible for this shop to handle a high-mix, low-volume manufacturing environment while maintaining the capacity for high-volume production when necessary.
Read: MoldMaking Technology's Most-Viewed Content 2022: Products
The combination of laser technology and a robot automation solution are critical for the shop. “With our custom fixtures, we can program a reference offset and know that we’re within two to three microns of accuracy when that fixture goes back in front of the laser. That kind of precision is key when you’re working at the micron level. We maintain the ambient shop temperature within four degrees to ensure the greatest possible accuracy,” President and CEO Matt Melonio says.
Throughout only a few decades, lasers have become an indispensable tool for moldmakers who have used this technology to achieve textures and precision beyond the capabilities of traditional milling or EDM machines. Today, laser micromachining and texturing have taken another big step forward thanks to femtosecond lasers, but laser technology pioneers will continue forging ahead in search of methods for pushing the limits of the technology.
About the Author
Jon Carlson
Jon Carlson is Product Manager, Advanced Manufacturing for GF Machining Solutions.
For More Information
Providence Texture
401-642-9490 /matt.melonio@providencetexture.com /https://providencetexture.com/
GF Machining Solutions LLC
847-955-7145 / jon.carlson@georgfischer.com / www.gfms.com/us
RELATED CONTENT
-
How to Choose the Right Plated Coatings for Improved Mold Performance
With a basic knowledge of plating types, moldmakers can make an educated coating choice that will improve mold performance.
-
Mold Cleaning Done Right Takes a Systematic Approach
Mold cleaning is just one part of a systematic and comprehensive approach to mold maintenance. Here’s one moldmaker’s strategy for injection mold cleaning and an explanation of where and why different techniques are employed.
(Video) How Lasers Work | Laser Micromachining | Lasers in Industry | Picosecond Lasers | Ultrafast Lasers -
How Surface Treatments Keep Molds Operating Longer
Important tips and information about mold coatings to help you achieve the level of production that you and your customers desire.
FAQs
Which laser is used in Micromachining? ›
Direct ablation using UV lasers is particularly attractive for micromachining polymers, and is increasingly used in manufacturing microfluidic bulk substrates.
What are the capabilities of laser Micromachining? ›Ultra-short-pulse, high-repetition-rate lasers are particularly well suited for micro-machining because of their ability to vaporize matter without generating heat, making them ideal for machining very small, very precise patterns, especially in materials that are difficult or impossible to machine by other methods.
What is laser beam micro machining? ›Laser micromachining (also laser beam micro-machining) means laser machining of very fine structures, typically on a scale between a few microns and a few hundred microns. The machined parts are not always very small, but at least the structures (e.g. holes, grooves or patterns) made on them.
What is Pico vs Femto laser? ›A picosecond (PS) laser emits optical pulses with a pulse duration around 10 PS – just over one trillionth (10-12) of a second, or one millionth of a microsecond. A femtosecond (FS) laser emits pulses that are one around 400 FS, less than one trillionth of a second in duration.
What is the need for Micromachining? ›Micromachining and nanotechnology play an increasingly decisive role in miniaturizing components ranging from biomedical applications to chemical microreactors and sensors. Millions of micromachined devices are used in automobiles and many other mechanical and electronic systems throughout the world.
What is micromachining used for? ›Micromachining allows engineers to create small, intricate parts. These parts can then be used in experiments, recreating large-scale processes at a tiny scale. Organ on a chip and microfluidics are two examples of uses for micromachining.
How can lasers be used for material processing? ›Laser Material Processing uses laser energy to modify the shape or appearance of a material. This method of material modification provides a number of advantages such as the ability to quickly change designs, produce products without the need for retooling, and improve the quality of finished products.
What is the most important feature of laser? ›Properties of laser light are: monochromacity (the same color), coherence (all of the light waves are in phase both spatially and temporally), collimation (all rays are parallel to each other and do not diverge significantly even over long distances).
Which of the following are the three most widely used micromachining processes? ›This assessment is to determine your knowledge and understanding of the three most common MEMS micromachining processes: surface, bulk, and LIGA.
Can we use the laser for the purpose of machining operation? ›During the machining process, a high-energy laser beam falls on the workpiece surface and removes the workpiece material by heating, melting, and vaporizing. Compared with other types of machining processes, LBM is the best method for the machining of brittle materials with low conductivity.
How many lasers are used in machining? ›
Types of lasers used for laser beam machining: Gas lasers such as CO2 and excimer lasers, along with solid-state lasers such as Nd:YAG and YAG lasers and femtosecond lasers, are some of the most popular lasers.
What is femto laser used for? ›Femtosecond-assisted (Femto) laser in-situ keratomileusis (LASIK) is a type of laser eye surgery. This method, along with other refractory surgeries, is used to reshape the cornea of the eye in an effort to resolve vision problems.
What does a femto laser do? ›What is Femto Laser-Assisted Cataract Surgery? Femtosecond laser-assisted cataract surgery (FLACS) allows surgeons to to use a laser to make bladeless corneal incisions that are more precise than the cuts made in traditional cataract surgery. The laser is the same technology that has been used in LASIK since 2001.
Which is better PicoWay or PicoSure? ›Power. The PicoWay laser also outshines the PicoSure laser with its superior peak power. While the PicoSure only peaks at 0.36GW, the PicoWay has a peak power of 0.9GW. This is important because more power ultimately means more effective removal of a tattoo.
What is the process of micromachining? ›The term 'micro-machining' refers to a machining process by which small ('microscopic') bits of material are removed in order to achieve a high geometrical accuracy that otherwise is unattainable.
What is the major problem in micromachining? ›Thermal deformation of the workpiece is the major problem in micromachining.
What is micromachining explain the steps involved? ›Step 1: Deposition of sacrificial layer • Step 2: patterning of the sacrificial layer • Step 3: deposit structural layer (conformal deposition) • Step 4: liquid phase removal of sacrificial layer • Step 5: removal of liquid - drying. Sacrificial. wet etching.
What are surface micromachining techniques? ›The surface micromachining processes - deposition, pattern and etch – are used to create the electronic sensing circuit by depositing chrome, then gold thin films on top of the silicon nitride, patterning the chrome/gold layers, then etching the chrome/gold to form the electronic circuit.
What are the advantages of surface micromachining? ›The main advantage is that the moveable structures are made from a single crystalline device layer hence have excellent, well-defined mechanical properties and high reliability. The SOI-wafer-based surface micromachining technology has been developed for capacitive inertial sensors.
What is the conclusion for micromachining? ›13.7 Conclusion
The fabrication of high quality and precise microfeatures and 3D microstructures can be effortlessly done using EMM. Smoother and more stable material removal process means greater control over process outcome than most other techniques.
Which is the most common laser material processing application? ›
CO2 and Nd:YAG lasers are the most common ones used in micromachining [15]. Improvements in the quality of the cutting, drilling, and micromachining of materials through the use of lasers have enabled us to produce finer details using laser-machining compared to more conventional engraving techniques.
What material absorbs lasers? ›Black Aluminum Foil
This durable, lightweight foil has a matte black finish to absorb light from any ambient or conventional light source. It can be molded quickly to form blackout covers, dark rooms, laser channels, or other configurations so as to mask light leaks or eliminate unwanted reflections.
Short pulse lasers can be used to process materials while producing virtually no heat affected zone. This allows them to machine plastics and brittle materials as well as they do metals.
What are the advantages of laser technology? ›No design limitations, no post-processing requirements, a high level of accuracy, easy to automate, and environmentally friendly.
What are the 5 properties of laser? ›- Coherence.
- Directionality.
- Monochromatic.
- High intensity.
Micromachining is often utilized to fabricate components for miniaturized sensors, medical, optical, and electronic devices. Common engineering materials for these applications include stainless steel, aluminum, titanium, copper, and tool steel for miniature molds and dies.
What materials are micromachining? ›Stainless steel is one of the most popular raw materials used for micromachining. This material is favored for its strength and resistance to corrosion over time. One of the benefits of stainless steel is that it can be welded vacuum tight.
What are the key challenges in fabrication of microstructures using surface micromachining? ›Technology. There are three key challenges in fabrication of microstructures using surface micromachining: Control of stress and stress gradient in the structural layer to avoid bending or buckling of the released microstructure. High selectivity of the sacrificial layer etchant to functional layers.
Which type of laser is used in microscopy? ›The lasers commonly employed in optical microscopy are high-intensity monochromatic light sources, which are useful as tools for a variety of techniques including optical trapping, lifetime imaging studies, photobleaching recovery, and total internal reflection fluorescence.
Which laser is used in laser cutting machine? ›CO 2 lasers are used for industrial cutting of many materials including titanium, stainless steel, mild steel, aluminium, plastic, wood, engineered wood, wax, fabrics, and paper. YAG lasers are primarily used for cutting and scribing metals and ceramics.
Which laser is used in laser beam machining? ›
Types of lasers used for laser beam machining: Gas lasers such as CO2 and excimer lasers, along with solid-state lasers such as Nd:YAG and YAG lasers and femtosecond lasers, are some of the most popular lasers.
Which laser is most commonly used? ›CO2 lasers are probably the most widely known gas lasers and are mainly used for laser marking, laser cutting, and laser welding.
What is the best type of laser? ›Diode: The diode laser is very effective for light and dark skin. Alexandrite: This laser is the fastest of all laser types and works best for treating larger body areas among patients who are have light-to-olive complexions. Nd:YAG: This long pulse laser can be used safely on all skin types, including tanned skin.
What are the three most common types of lasers used in part production manufacturing? ›The three main types of lasers include: a CO2 laser (best suited for cutting and boring); a Nd or neodymium laser (for boring and welding materials requiring high energy and low repetition); Nd-YAG or neodymium yttrium-aluminium-garnet laser (for high-power engraving, welding and boring).
Which laser is widely used in mechanical industry? ›Ultrafast lasers are typically used for various types of metals and polymers because they cut clean edges and do not create heat-affected zones. Lasers can cut a wide variety of materials, including aluminum, titanium, and steel, with micron-level tolerances.
What is the most powerful cutting laser? ›Known as the Zetawatt-Equivalent Ultrashort pulse laser System (ZEUS), it produces an ultra-short, extremely powerful pulse of just 25 femtoseconds. A femtosecond is a quadrillionth of a second – or to put it another way, a femtosecond is to a second what a second is to about 31.71 million years.
What software do most laser cutting machines? ›Adobe Illustrator is the gold standard against which all other design software is measured. One feature that makes Adobe Illustrator shine as a program for laser cutting is its Artboards setup.
What are the two main types of lasers cutting machine for sheet metal processing industry? ›There are three different types of laser technology used for sheet metal machinery; carbon dioxide, Nd:YAG and fibre. In this article, we take a closer look at the various laser technologies available. First developed in 1964, CO2 lasers are the highest powered type of laser on the market.
Why laser is used for machining? ›Due to higher coherency of laser beam, materials can be machined very precisely than conventional machining processes. Generally, the laser-based material processing is suitable for a brittle type of material with minimum conductivity. However, this laser machining can be used for all kinds of materials in most cases.
Which laser is used most widely in industrial materials processing applications? ›With installations in the thousands, the AVIA is the most widely adopted high power Q-switched laser for materials processing. This family of diode-pumped, solid-state products, is available in wavelengths of 355 nm and 532 nm.