Protection against radiation
The progress rate with laser welding is considerably higher than with TIG welding. With laser welding, a welding speed can be achieved that is at least four to six times faster than TIG welding.
Preventing fire hazards
The basic skills of laser welding can be learned within a few hours. The welder must develop a feeling for the high speed and properly position the laser spot in the right place. Welding I-seams is often easier when a stop is used. The welding gun can then easily be advanced in the correct line.
Limit toxic fumes
Due to the high speed and the small melt pool, the surface area affected by the heat is also small. In almost all cases the weld seam can be cleaned in one go with a non-woven abrasive.
Training and knowledge
Due to the very low heat input during laser welding, the deformation of material is often negligible. By applying manual laser welding, you can save the time required for clamping the product. Less time will also be required to align products after welding.
Laser safety for laser cleaning and welding
Safety when laser welding deserves great attention. The welding process offers important advantages and can achieve higher quality of products in combination with more efficient production. As a guideline for safe laser welding we should look at EN 60825-1:2014. This standard classifies lasers and sets requirements for the safety features associated with a particular laser class.
Laser welding machines and laser cleaning machines are class 4 lasers. In the classification of laser equipment, class 4 is the category with the most risks. Despite the risks, safe laser welding and laser cleaning is certainly possible.
Lasers with a power greater than 500 MW where humans have access to the laser radiation fall under class 4. The powers used for manual laser welding and laser cleaning often have a power of 1000 to 2000 Watts. Lasers with this power can easily ignite materials or cause very serious injuries.
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Characteristics of laser light
The laser light used in manual laser welding is in the non-visible infrared spectrum (IR –A). As a result, in addition to the direct laser beam, the reflections of the laser light are also not visible. The direct laser light and laser light that reflects specularly diverges to a limited extent, which means that the intensity of the laser can be dangerous and harmful even at great distances.
When striving for a high degree of laser safety, it is therefore essential to also take (diffuse) reflections into account.
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Risks of laser light
The laser light released during laser welding and laser cleaning is harmful to the skin and eyes. Since the eyes do not detect the invisible infrared light, the eye will not close as it does with strong visible light.
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Risks for the skin
Laser radiation can cause serious injuries to the skin. The severity obviously depends on the power of the laser beam. Another factor that determines how deeply the laser burns into the skin is the wavelength. The wavelength of 1080 nm that is used in most cases for manual laser welding and laser cleaning causes a deep penetration into the skin. The skin will heal after a burn, but may develop scar tissue depending on the severity of the injury.
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Risks to the eyes
Depending on the wavelength of the radiation, the human eye can be damaged in different locations when exposed to radiation at power levels above safe levels. This damage can vary depending on the wavelength, because the eye is more sensitive to certain wavelengths than others.
Radiation is absorbed in the cornea (Cornea)
Resulting in snow blindness/welding eyes
Wavelength 400-1400 nm visible light and infrared (IR-A)
Radiation is projected onto the retina
Can cause burns resulting in blindness
Absorption of light in the lens, the damage builds up slowly
Wavelength 1400 nm-1 mm Infrared light (IR-B & IR-C)
Most radiation is absorbed by the cornea
Results in burn marks on the retina
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Occupational hygiene strategy
With regard to limiting risks within companies when dealing with hazardous substances or processes, following the work hygiene strategy is good practice.
This methodology can also be used to create an environment in which laser welding can be done safely.
The following steps from the occupational hygiene strategy help to increase laser safety:
Apply technical measures, work processes, equipment and materials that eliminate or limit risks.
Take collective protection measures at the source or take organizational measures.
Provide personal protective equipment for employees who are (or may be) exposed to hazardous substances.
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Practical steps laser safety
Safe laser equipment
Laser equipment, like all other machines, must comply with several European standards and regulations, such as the Machine Directive and the Low Voltage Directive.
EN 60825-1:2014 also applies to equipment that incorporates laser technology. This standard describes the different types of lasers as well as the safety measures to be taken that are associated with a particular type of laser.
Requirements that must be met for class 4 lasers:
Fail safe control
Key security
Fail safe Interlock facility
Warning stickers
Fail safe warning lighting
Shielding
Preferably, a laser welding installation should be used in a closed space. Such a space can be provided with an interlock circuit. Lighting can be installed on the outside to indicate the status (on/off) of the laser.
In this way, safe laser welding or laser cleaning can best be guaranteed. However, it is not possible in all cases to work with a fixed space.
If you want to weld laser safely on location or in a large workshop, this can usually be achieved with mobile shielding. This shielding must comply with EN 12254:2014-04. To select the correct laser workshop shielding, the power and wavelength of the laser radiation must be taken into account. LAZRZ offers various products that can contribute to safe laser welding on location or in a workshop.
Knowledge and skills in Laser safety
Users and other involved parties must be well informed about the safety aspects required when using laser welding equipment. Within the company, people must be aware of work instructions that guarantee safety. The (Dutch) practical guideline NPR-CLC/TR 50448:2005 states that when using a class 4 laser, a person in the organization must be designated and trained as a Laser Safety Officer (LSO).
Personnel protection
Personal protective equipment is indispensable when working safely with hand lasers. Many protective equipment cannot sufficiently withstand the direct (and long-term) laser radiation from a handheld laser welding machine or laser cleaner. However, the right protective equipment does provide good protection against short-term direct radiation or reflections. The right protective equipment makes safe working very possible.
Laser safety glasses
The selection of the right type of safety glasses must be done with the necessary care. On the page regarding laser safety glasses we further explain the selection of the right product..
Laser Safety Gloves and Clothing
To select the right laser safety products, it is important that the welder’s clothing is tailored to the type of laser. The standards for protective clothing are not yet sufficient for many applications. Protective clothing against laser radiation is available, and leather welding clothing is also in many cases sufficiently protective against (short-term) laser radiation..