Continuous and pulsed laser cleaning machines are two types of lasers for laser cleaning machines.

This article will focus on the working principle, laser characteristics, specific applications, etc. of pulsed laser cleaning machines and continuous laser cleaning machines. At the same time, the differences between the two will be analyzed in depth. At the end of the article, we will give professional laser cleaning machine purchase guidance.

1. What is a pulsed laser cleaning machine?

1.1 Working principle of pulsed laser cleaning machine

To understand what a pulsed laser cleaning machine is, you must first understand what a pulsed laser is.

Pulse laser can be understood as: every short time interval, the laser will be concentrated once, and the light will be continuously emitted repeatedly, so the pulsed light has a prominent time interval characteristic.

Pulse lasers can achieve high peak power precision laser cleaning tasks by adjusting the pulse width and pulse frequency.

1.2 Two output beam modes of pulsed laser cleaning machines: single mode and multi-mode

Pulse laser cleaning machines are divided into single-mode pulsed laser cleaning machines and multi-mode pulsed laser cleaning machines according to the beam quality, spot size, energy distribution, and output power.

Single-mode pulse laser beam quality is higher, M² value can be close to 1, the spot is smaller, the laser output energy is more concentrated, and the energy distribution of single-mode pulse laser is Gaussian distribution, high in the middle and low on both sides. These characteristics make the beam of single-mode pulse laser sharper, like a needle tip, and more effective in removing pollutants such as oil, rust, etc.

However, the fiber core used by single-mode laser is thinner, generally about 4-10 microns, so the output power of single-mode pulse laser is lower than that of multi-mode pulse laser.

Multi-mode pulse laser has larger spot size, wider beam distribution, and flat-top energy distribution, like a small flat-top house. When performing laser cleaning tasks, it sweeps back and forth like a wide broom. Compared with single-mode pulse laser, multi-mode pulse laser has softer beam. In addition, multi-mode pulse laser has greater output power, so the cleaning efficiency is faster.

Multi-mode pulse laser has high output power and large spot size, which is the best choice for cleaning large areas or thick layers.

1.3 Features of pulse laser cleaning machine:

High peak power: The pulse laser cleaning machine releases high energy in the form of short pulses, and can release high energy in a very short time, so it has a high peak power. When performing laser cleaning tasks, not only can the higher laser energy be used to remove oxide layers, oil stains, rust, etc., but the thermal impact on the substrate is also minimal and will not cause damage.

Adjustable pulse width: Our pulse laser cleaning machines all use MOPA (Master Oscillator Power Amplifier) lasers, so the pulse width can be adjusted according to demand. If you want to remove light rust, oxide layers or thin coatings or have higher requirements for the surface of the substrate, you can adjust to a shorter pulse width. If you need to clean thicker or stubborn contamination layers, such as paint, heavy rust or thick oxides, you can adjust to a longer pulse width.

Adjustable pulse frequency: The pulse frequency of the pulse laser cleaning machine is also adjustable. If you want to remove more stubborn contaminants, you can adjust it to a low frequency, but the cleaning speed will be relatively slow. If you want to clean a lighter contamination layer or have higher requirements for the surface of the cleaning material, you can adjust it to a high frequency by yourself.

1.4 Application of pulse laser cleaning machine:

Applicable materials: Pulse laser cleaning machine can clean most metal and non-metal materials. Generally used for metal materials. For example, ordinary iron, copper, aluminum alloy, stainless steel, etc.

Some metals come into contact with moisture and oxygen in the air, undergo oxidation reactions, and generate some oxides, oxide scales or rust; some metals come into contact with various lubricants and protective oils during production, processing, transportation, and use, and thick oil stains will form over time. Laser cleaning machines can clean them well.

Application industries: Pulse laser cleaning machines are widely used in various industries, such as the automotive manufacturing industry, mold industry, various transportation industries, etc. These industries are prone to the accumulation of oil stains, oxide layers, rust layers, sticky substances and other dirt.

Traditional cleaning methods take a long time and need to be more thorough, while pulse laser cleaning machines are more efficient, more detailed, and more non-destructive, and can quickly remove various surface dirt.

2. What is a continuous laser cleaning machine?

2.1 Working principle of continuous laser cleaning machine

Continuous laser cleaning machine refers to continuous wave laser (CW laser). By continuously emitting high-energy continuous beams to act on the surface of the workpiece, the laser energy instantly heats and vaporizes the oxide layer, rust, oil, coating and other pollutants on the surface of the workpiece, decomposing, vaporizing or peeling them off without damaging the substrate.

2.2 Characteristics of continuous laser cleaning machine

High power and continuous output: The continuous laser cleaning machine can continuously output high-energy laser beams. Suitable for large-area, high-efficiency cleaning.

Non-contact cleaning: No need to contact the workpiece to avoid physical wear.

Non-destructive cleaning: The cleaning process only targets pollutants and does not damage the substrate. It is suitable for a variety of metal and non-metal materials.

2.3 Application of continuous laser cleaning machine:

Application materials

Continuous laser cleaning machines are generally used for large metal materials. Especially suitable for removing heavy rust, thick coatings, and industrial-grade pollution.

Application industry

Continuous laser cleaning machines quickly remove pollutants on the surface of workpieces through high-power continuous beams, which is suitable for cleaning scenarios with large areas and thick layers of pollution. Combined with the single pendulum and double pendulum modes, efficient, environmentally friendly and non-destructive cleaning effects can be achieved for different workpiece shapes, cleaning areas and pollution levels.

Continuous laser cleaning machines play an important role in many fields such as automobiles, ships, rail transit, energy, etc.

3. Main differences: continuous and pulsed laser cleaning machines

3.1 Output power intensity

Generally speaking, the greater the power of the laser cleaning machine, the higher the cleaning efficiency. The power range of the pulsed laser cleaning machine is 50 watts to 1000 watts, and the power of the continuous laser cleaning machine is 1500 watts to 3000 watts. In this way, the continuous laser cleaning machine has more advantages in cleaning efficiency.

However, it should be noted that during the cleaning process with excessive power, the substrate temperature will be too high, causing more obvious damage to the surface of the material.

3.2 Cleaning depth

For stubborn dirt, the cleaning effect of the pulsed laser cleaning machine will be more thorough.

Due to the working principle of the pulsed laser cleaning machine, the energy of the pulsed laser is more concentrated and the spot is smaller, so it can deeply clean the dirt accumulated for a long time. For example, oxides, rust, coatings, paint oil stains, etc.

3.3 Cleaning effect

After the pulse laser cleaning machine cleans the material, there is almost no damage to the bottom of the substrate. Not only that, after cleaning the material, it can also be very close to the original base color of the material. After the continuous laser cleaning machine is cleaned, a slight white mark will be left on the surface of the metal material. Although the cleaning is very good, its appearance effect may be better than that of the pulse laser cleaning machine.

3.4 Suitable cleaning for different materials

We used a 1000-watt pulse laser cleaning machine and a 1500-watt continuous laser cleaning machine to test rust and oil stains.

(1) For mild rust, both pulse and continuous lasers can easily remove it. Both have good cleaning speed and effect. However, for thicker rust and larger areas, continuous laser can provide better cleaning effect.

(2) For oil stains, pulse laser cleaning is more thorough and effective, and it hardly damages the material. Continuous laser is less effective in removing oil stains and may leave some black residue on the surface.

If you need to clean a thick rust layer, it is recommended to use a continuous laser cleaning machine. If you need to clean oil stains and thin rust layers, pulse laser is a better choice.

3.5 Effect of heat on materials

The pulse laser cleaning machine uses short pulses for cleaning, so the laser will not always irradiate the surface of the material, and the heat accumulation is minimal. It is suitable for processing heat-sensitive materials.

During the long cleaning process of the continuous laser cleaning machine, due to the large light cutting power, the accumulated heat is large, which may cause thermal effects on the cleaning materials.

3.6 Light uniformity

The laser of the pulse laser cleaning machine is continuously output at very short intervals, with a high peak power, while the laser output of the continuous laser cleaning machine is stable and continuous, so its beam uniformity will be better.

3.7 Price and cost

The cost of the pulse laser cleaning machine is higher because it requires a more complex control system to generate high peak power laser pulses, coupled with a high-precision optical system and cooling device, the overall price is higher than that of ordinary continuous laser systems.

The price of continuous laser cleaning machines is relatively cheap, especially the continuous laser system with mature technology, because the output power is stable and relatively simple, the production and maintenance costs are low.

4. How to choose a suitable laser cleaner?

Choosing a suitable laser cleaning machine is a process that requires comprehensive consideration of multiple factors. The following points can help you make the best choice:

4.1 Materials to be cleaned

Pulse laser cleaning machines are suitable for cleaning heat-sensitive or relatively expensive materials, such as thin metals, precious metals, composite materials, coating-sensitive materials, etc. Since the heat-affected zone of pulse lasers is small, deformation or damage of materials can be effectively avoided.

Continuous laser cleaning machines are more suitable for cleaning high-temperature resistant or thicker metal materials, such as steel, iron, cast aluminum, etc. The stable output of continuous lasers is very suitable for large-area, deep-level cleaning.

4.2 Expected cleaning effect

During the cleaning process, the pulse laser cleaning machine will basically not cause damage to the substrate. For the material itself, it is more protective. After cleaning by the pulse laser cleaning machine, the material will be closer to its own color, without coating and dirt.

Continuous laser cleaning machines use high-power lasers to quickly heat and evaporate pollutants during the cleaning process, which is suitable for the initial removal of large areas and stubborn stains. Thick rust and coatings can be efficiently stripped, but due to the large heat input, the protective effect on the substrate is relatively weak. Continuous lasers are more suitable for industrial cleaning tasks that do not require high material damage.

4.3 Procurement budget

The price of pulsed laser cleaning machines is generally higher than that of continuous laser cleaning machines, especially high-power pulsed laser equipment, but pulsed lasers can flexibly adjust parameters such as pulse width, and are suitable for a wider range of materials and applications.

On the other hand, continuous laser cleaning machines are more affordable than pulsed laser cleaning machines, especially medium and low-power models. If you have a limited budget and need to clean a larger area, and prioritize cleaning efficiency over cleaning accuracy, then a continuous laser cleaning machine may be a better choice.

Summary

Continuous and pulsed laser cleaning machines can meet various cleaning needs. Continuous lasers and pulsed lasers each have their own advantages and can be flexibly selected according to the application scenario.

Due to their working principle and laser characteristics, pulsed laser cleaning machines have extremely small heat-affected zones and can achieve deep cleaning. They are ideal for applications with high surface quality requirements or where substrate protection is critical.

On the other hand, continuous laser cleaning machines have the characteristics of high power and high efficiency, making them more suitable for large-scale cleaning tasks and handling stubborn contaminants such as severe rust or thick paint layers.

After reading this article, you can better understand the difference between continuous laser cleaning machine and pulse laser cleaning machine, and choose the most suitable laser cleaning machine according to your actual needs.