Powering the Automotive Industry: The Preference for Carbon Dioxide Lasers in Automotive Manufacturing
A typical vehicle contains components that have undergone carbon dioxide laser processing in every location.
Plastics, metals, fabrics, glass, and rubber are a few of the numerous materials used in contemporary car manufacture. Modern carbon fiber may be used in high-end and luxury vehicles in addition to more conventional materials like wood and leather. The carbon dioxide (CO2) laser is a versatile tool that can process many materials. The CO2 laser, one of the earliest technologies, was created in 1964. Despite this, it is still a staple of contemporary production and has numerous applications in the automobile sector.
CO2 lasers are available with output powers ranging from a few tens of watts to many kilowatts, making them useful for a variety of different processes; low power levels are used primarily to mark and engrave, while higher powers can cut and weld with ease and precision. As a result, laser-processed components find their way into almost all areas of a typical vehicle, both interior and exterior (FIGURE 1).
Plastic cutting
The processing of plastic parts, including dashboard and interior panels, pillars, bumpers, spoilers, trims, license plates, and lamp housings, is frequently done using CO2 lasers for plastic cutting. Thermoplastic polyolefin (TPO), polypropylene, polycarbonate, high-density polyethylene (HDPE), acrylic, and different composites and laminates, are just a few of the many plastics that are employed. Plastics can be plain or painted, and they can be combined with other materials to create trim panels made of composite or veneered materials, fabric-covered interior pillars, and support systems reinforced with carbon or glass fibers.
Lasers can be used to cut and drill holes or trim extra plastic left over from the injection molding process and to cut or drill holes for fixing points, lights, switches, parking sensors, and other components. Clear plastic headlamp housings and lenses frequently require laser trimming to get rid of tabs of leftover waste plastic from the molding process. Polycarbonate is typically used to make lamp parts because of its optical clarity, strong impact/shatter resistance, weather resistance, and resistance to UV rays. The laser cutting technique gives this particular plastic a rough appearance; however, after the headlamp is built correctly, it is impossible to see the rough edges. The smooth edges of many different polymers can be cut with a high-quality finish, eliminating the need for additional modification or cleaning during the post-processing stage.
Depending on the amount of time available to accomplish the task, laser power for plastic cutting operations ranges from 125 W and more; the SR, SCX, and OEM series from Luxinar are all suited for these applications. For most plastics, the relationship between laser power and processor speed is linear, so double the laser’s power is required to double the cutting speed. When calculating the overall cycle time for a sequence of operations, handling time must also be considered so that the laser power can be selected appropriately. Robotic technology excels in managing complex handling needs and cutting procedures that commonly require the laser beam or the component to move in three dimensions.
Robotics
Robots have long been a staple of the automotive industry, and modern production is highly automated. In conjunction with this technology, lasers are now employed to replace traditional tools and bring a variety of additional advantages to the production process.
A distinct set of difficulties are presented by robotic laser integration. The laser can be used in robotic applications in one of three ways:
- A sophisticated articulated beam delivery system transfers the laser’s beam to the workpiece after being installed directly onto the robot arm. The robot is then trained to carve reasonably intricate designs while continuously maintaining the focus of the beam (FIGURE 2).
- The component can also be moved by the robot while it is in front of a stationary laser beam. The maximum size of the components is restricted, but this is a mechanical technique that is simpler and may be employed with smaller robots.
- The robot mounts an articulated arm to the laser and moves the arm to the precise location where the pieces are to be cut.
The laser must survive the G-forces generated by the robot’s motion for the first of them to work. The robot must be strong and powerful enough to support and move the laser. Or, to put it another way, the laser must be small and light enough to be mounted directly on the robot arm. The SR series lasers from Luxinar are perfect in this regard. In the second technique, the laser beam is frequently guided by a galvanometer scanner as the robot offers up the component. High-speed cutting of holes and microscopic features often involves many cuts at each robot position. Drilling tiny holes across the surface of an instrument panel, typically 1 mm in size, is a typical application. This enables a vacuum on the back side to eliminate air spaces as the cover stock is bonded to the outer surface. Similar techniques can be used to cut larger holes and features, such as those needed for installing switches and sensors.
Textile cutting
Several different textile materials are frequently used in car interiors, with upholstery cloth being the most noticeable. In some instances, lasers can be used for patterning and cutting fabric. The kind and thickness of the cloth will affect the processing speed. However, a more powerful laser will cut at a proportionately faster rate. Most synthetic fabrics are neatly cut, and the edges are sealed to prevent fraying during later stitching and car seat installation (FIGURE 3). Real and fake leather can both be cut similarly for car upholstery. Lasers are routinely used to complete the fabric coverings, frequently found on many consumer vehicles’ interior pillars. Lasers are routinely used to complete the fabric coverings, frequently found on many consumer vehicles’ interior pillars. Fabric is fused to these plastic components during the molding process, necessitating the trimming of surplus fabric from the edges before assembly in the car. Once more, this is a five-axis robotic operation, and the cutting head precisely trims the fabric while following the part’s contours. For these purposes, moderately powered CO2 lasers are frequently employed.
Technical textiles are employed in a vehicle’s safety systems, such as seat belts and airbags. Therefore fabrics are used for more than just aesthetics and comfort. Modern cars often come equipped with numerous airbags as standard equipment to protect both the driver and passengers. To achieve the appropriate air permeability, airbag materials are typically constructed from tightly woven nylon or polyester fibers that are frequently silicone-coated. When an airbag is flat-woven, the bag’s structure is formed on the loom and then sewn together. The structure is entirely constructed on the loom when an airbag is one-piece-woven (OPW). Both types need trimming, and a CO2 laser is the best tool for the job. The laser cutting method is effective and dependable, minimizing waste by constantly producing high-quality cuts. Due to the method’s noncontact nature, handling of the fabric is limited. As a result, the silicone coating is less likely to sustain damage that could jeopardize the airbag’s integrity.
The fact that the same technology can be used to score lines in the dashboard and door skins of automobiles, selectively weakening the structure so that a flap bursts apart to release the airbag in the case of a collision, is evidence of the CO2 laser’s adaptability. The reverse side of the interior panels is used for this laser scoring, which must be done with incredibly tight tolerances and has no noticeable aesthetic influence on the vehicle’s passengers.
Surface texturing
Cutting, drilling, and trimming with lasers are not the only laser processing methods used in the automotive industry; CO2 laser ablation is also widely used in this sector. An excellent illustration is the surface alteration or removal of paint from specific plastic or composite sections. When fixing a component with adhesive to a painted or lacquered surface, it is frequently essential to remove the top coat of paint or to roughen the surface to encourage strong adhesion. The laser is utilized with a galvanometer scanner to quickly run the laser beam over the desired region in a raster or cross-hatched pattern. The laser delivers enough energy to ablate the surface without causing substantial material damage. It is simple to create precise geometries, adjust ablation depth and surface texture, and change ablation patterns as needed with the least amount of effort. In some circumstances, a process previously carried out by hand may be replaced by laser technology, resulting in significant time savings and enhancements to quality and consistency.
Contrary to popular belief, laser-based manufacturing is not just for high-end autos and future concept cars. When examined closely, any current consumer automobile will have several parts impacted by a CO2 laser. Perhaps security information has been carved into the tires’ rubber or marked on the windows. To improve water flow while in operation, small drainage holes might be drilled in the wiper blades, or even smaller ones could be formed in the rubber door seals. A hybrid or electric vehicle’s braking discs might have undergone an ablation cleaning procedure, or copper hairpins inside the motor might have had enamel selectively removed. Number plates, instrument panels, door skins, lamp covers, interior pillars, filter housings, and air intake ducts are just a few plastic components that might have been cut or trimmed with a CO2 laser. The CO2 laser is incredibly versatile, and automakers continuously develop new applications for this age-old technology.