powerful laser rust removal



Laser Photonics (Orlando, FL), which makes fiber and CO2 laser machines for marking, cleaning, cutting, and engraving, has launched what the company says is the first 2000 W handheld laser cleaning machine that is fully capable of meeting health and environmental regulations in manufacturing environments.


Laser cleaning aims at minimizing chemical and abrasive usage in industrial environments to meet increasing compliance with OSHA and EPA requirements' the stricter compliance regulations require safer practices in addressing pollution and health concerns.


Laser Photonics says that the laser cleaning system, called Cleantech LPC 2000CTH, uses a high-powered, energy-efficient laser to clean a variety of materials and is well suited for industrial manufacturers operating with components that have to withstand high-temperature environments, such as maintenance and repair facilities for military, shipbuilding, and aircraft repair facilities as well as turbines, jet engines, and combustion motors.


The technology has seen a wave of adoption by big players in industries such as aerospace, automotive, military and defense, power generation, and marine and shipbuilding, says the company.


Laser cleaning works by directing a high-powered laser beam at a material ready for cleaning, rust removal, corrosion removal, decontamination, depainting, prewelding, or other surface preparation processes. This process can substitute for or replace industrial cleaning processes such as abrasive blasting, sandblasting, and wet chemical processes for decontamination or corrosion removal. The LPC 2000 CTH cleans materials made of aluminum, anodized aluminum, alloy metals, stainless steel, mild steel, copper, brass, nontransparent plastics, plaques, and others.


According to Laser Photonics, the LPC 2000 CTH is the fastest laser cleaner available in the market that does not damage the base material of components. Different modes of operations allow the laser to remove charring, rust, or paint at high speeds and volumes but is gentle enough to clean small, delicate parts.

 Laser ablation or photoablation is the process of removing material from a solid (or occasionally liquid) surface by irradiating it with a laser beam. At low laser flux, the material is heated by the absorbed laser energy and evaporates or sublimates. At high laser flux, the material is typically converted to a plasma. Usually, laser ablation refers to removing material with a pulsed laser, but it is possible to ablate material with a continuous wave laser beam if the laser intensity is high enough. Excimer lasers of deep ultra-violet light are mainly used in photoablation; the wavelength of laser used in photoablation is approximately 200 nm.

Fundamentals

The depth over which the laser energy is absorbed, and thus the amount of material removed by a single laser pulse, depends on the material's optical properties and the laser wavelength and pulse length. The total mass ablated from the target per laser pulse is usually referred to as ablation rate. Such features of laser radiation as laser beam scanning velocity and the covering of scanning lines can significantly influence the ablation process.


Laser pulses can vary over a very wide range of duration (milliseconds to femtoseconds) and fluxes, and can be precisely controlled. This makes laser ablation very valuable for both research and industrial applications.

Applications

The simplest application of laser ablation is to remove material from a solid surface in a controlled fashion. Laser machining and particularly laser drilling are examples; pulsed lasers can drill extremely small, deep holes through very hard materials. Very short laser pulses remove material so quickly that the surrounding material absorbs very little heat, so laser drilling can be done on delicate or heat-sensitive materials, including tooth enamel (laser dentistry). Several workers have employed laser ablation and gas condensation to produce nano particles of metal, metal oxides and metal carbides.


Also, laser energy can be selectively absorbed by coatings, particularly on metal, so CO2 or Nd:YAG pulsed lasers can be used to clean surfaces, remove paint or coating, or prepare surfaces for painting without damaging the underlying surface. High power lasers clean a large spot with a single pulse. Lower power lasers use many small pulses which may be scanned across an area. In industrial application, laser ablation is known as laser cleaning.



Industrial 500W laser cleaning equipment.

One of the advantages is that no solvents are used, therefore it is environmentally friendly and operators are not exposed to chemicals (assuming nothing harmful is vaporized).[citation needed] It is relatively easy to automate. The running costs are lower than dry media or dry-ice blasting, although the capital investment costs are much higher. The process is gentler than abrasive techniques, e.g. carbon fibres within a composite material are not damaged. Heating of the target is minimal.


Another class of applications uses laser ablation to process the material removed into new forms either not possible or difficult to produce by other means. A recent example is the production of carbon nanotubes.


Laser cleaning is also used for efficient rust removal from iron objects; oil or grease removal from various surfaces; restoration of paintings, sculptures, frescoes. Laser ablation is one of preferred techniques for rubber mold cleaning due to minimal surface damage to the mold.


In March 1995 Guo et al.[2] were the first to report the use of a laser to ablate a block of pure graphite, and later graphite mixed with catalytic metal.[3] The catalytic metal can consist of elements such as cobalt, niobium, platinum, nickel, copper, or a binary combination thereof. The composite block is formed by making a paste of graphite powder, carbon cement, and the metal. The paste is next placed in a cylindrical mold and baked for several hours. After solidification, the graphite block is placed inside an oven with a laser pointed at it, and argon gas is pumped along the direction of the laser point. The oven temperature is approximately 1200 °C. As the laser ablates the target, carbon nanotubes form and are carried by the gas flow onto a cool copper collector. Like carbon nanotubes formed using the electric-arc discharge technique, carbon nanotube fibers are deposited in a haphazard and tangled fashion. Single-walled nanotubes are formed from the block of graphite and metal catalyst particles, whereas multi-walled nanotubes form from the pure graphite starting material.


A variation of this type of application is to use laser ablation to create coatings by ablating the coating material from a source and letting it deposit on the surface to be coated; this is a special type of physical vapor deposition called pulsed laser deposition (PLD),[4] and can create coatings from materials that cannot readily be evaporated any other way. This process is used to manufacture some types of high temperature superconductor and laser crystals.


Remote laser spectroscopy uses laser ablation to create a plasma from the surface material; the composition of the surface can be determined by analyzing the wavelengths of light emitted by the plasma.


Laser ablation is also used to create pattern, removing selectively coating from dichroic filter. This products are used in stage lighting for high dimensional projections, or for calibration of machine vision's instruments.

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