FDA
FDA 21 CFR 1040.10 - Laser Product Performance Standards
Todd DunningMAUnited States
Optical Materials for Laser SystemsPublished
Dec 16, 2025
Brick Laser Cleaning
When laser cleaning brick, we've found that its thermal stability lets us remove surface contaminants effectively while preserving the material's long-term structural integrity
Laser-Material Interaction
Absorptivity
0.85
0.7
0.85
0.95
Absorption Coefficient
5e6
m⁻¹
1e6
5e6
1e7
Laser Damage Threshold
2.5
J/cm²
1
2.5
5
Thermal Shock Resistance
2
MW/m
1
2
4
Reflectivity
0.15
0.05
0.15
0.3
Thermal Destruction Point
1,473
K
1,273
1,473
1,673
Vapor Pressure
0.1
Pa
0.001
0.1
10
Thermal Destruction
1,323
K
273
1,323
2,500
Laser Reflectivity
0.28
0.21
0.28
0.33
Thermal Expansion
6e-6
1/K
6e-6
6e-6
1.2e-5
Thermal Conductivity
0.72
W/m·K
0.08
0.72
2.5
Specific Heat
880
J/(kg·K)
828
880
1,102
Laser Absorption
0.92
0.11
0.92
1.3e5
Thermal Diffusivity
4.3e-7
m²/s
0
4.3e-7
1e-6
Ablation Threshold
1.1
J/cm²
0.85
1.1
4.2
Brick Laser Cleaning Material Characteristics
Fracture Toughness
0.75
MPa√m
0.15
0.75
1.1
Density
1,920
kg/m³
682
1,920
3,268
Oxidation Resistance
0.98
dimensionless (scale 0-1, where 1 indicates complete resistance)
0
0.98
1,155
Youngs Modulus
11
GPa
11.4
11
1.2e10
Hardness
2.5
Mohs
0.28
2.5
36.7
Compressive Strength
20
MPa
5
20
100
Tensile Strength
2.5
MPa
1
2.5
15
Flexural Strength
8.3
MPa
0.84
8.3
13.1
Corrosion Resistance
0
mm/year
0.02
0
105
Laser Damage Threshold
2.5
J/cm²
1.1
2.5
8.8
Thermal Destruction
1,323
K
273
1,323
2,500
Laser Reflectivity
0.28
0.21
0.28
0.33
Thermal Expansion
6e-6
1/K
6e-6
6e-6
1.2e-5
Thermal Conductivity
0.72
W/m·K
0.08
0.72
2.5
Specific Heat
880
J/(kg·K)
828
880
1,102
Laser Absorption
0.92
0.11
0.92
1.3e5
Thermal Diffusivity
4.3e-7
m²/s
0
4.3e-7
1e-6
Brick surface magnification
Before Treatment
The brick surface at this magnification reveals a dense layer of grimy particles clinging tightly to every crevice. Dark residues fill the irregular pores, creating an uneven and mottled appearance overall. Contamination obscures the underlying texture, making the material look dull and obscured.
After Treatment
Laser treatment removes the grimy particles, restoring a uniform and clear surface view. Clean pores now expose the brick's natural, even texture without any residues. The material appears revitalized, with its original details sharply visible and
Regulatory Standards & Compliance
ANSI
ANSI Z136.1 - Safe Use of Lasers
IEC
IEC 60825 - Safety of Laser Products
OSHA
OSHA 29 CFR 1926.95 - Personal Protective Equipment
Brick Laser Cleaning Laser Cleaning FAQs
Q: What laser settings work best for cleaning soot and pollution stains from historical brick without damaging the surface?
A: Preserves fragile brick substrate. When working with historical brick, typically start with conservative settings like 12 J/cm² fluence and 100W average power. Pretty much always run test patches first, since heavy carbon deposits could demand a touch more energy than light soot. The 1064 nm wavelength proves ideal for stripping contaminants while safeguarding the fragile brick substrate.
Q: Can laser cleaning remove paint and graffiti from brick without using chemicals or abrasives?
A: Preserves porous substrate. Yes, laser cleaning effectively strips paint and graffiti from brick without relying on chemicals or abrasives. With a 1064 nm wavelength at about 12 J/cm², the process basically vaporizes coatings such as acrylics and spray paints, all while safeguarding the porous substrate. Typically, 2-3 passes suffice to clear pigment residue from the masonry's texture, providing a superior, more controlled option over traditional approaches.
Q: Does laser cleaning cause any color change or surface fusion on brick surfaces?
A: Preserves original patina. Properly tuned near-IR lasers at 1064 nm with about 12 J/cm² fluence basically remove contaminants without changing the brick's color. The mineral composition stays intact, fairly well preserving the original patina while dodging surface fusion or thermal darkening.
Q: How does laser cleaning compare to sandblasting for brick restoration in terms of surface damage and mortar preservation?
A: Preserves delicate mortar joints. Laser cleaning at 12 J/cm² fluence fairly selectively removes contaminants without abrasion, preserving delicate mortar joints. Unlike sandblasting, it typically maintains the brick's original surface profile while eliminating harmful dust production, ensuring structural integrity.
Q: What safety precautions are specific to laser cleaning brick, especially regarding silica dust and lead paint?
A: When cleaning brick at 100 W and 1064 nm, the primary hazard is typically respirable crystalline silica dust. Basically, you must use a NIOSH-approved P100 respirator and local exhaust ventilation to capture these fine particulates, especially if lead-based paint is present.
Q: Why does brick sometimes turn pink or orange after laser cleaning, and is this permanent?
A: Thermal reduction of iron oxides. The pink hue basically stems from thermal reduction of iron oxides in the clay at fluences around 12 J/cm². This chemical state remains pretty permanent overall, though it signals no structural damage to the brick substrate.
Q: What's the maximum removal rate for heavy biological growth (lichens, moss) from brick using laser cleaning?
A: 500 mm/s optimal removal. When dealing with heavy biological growth on brick, we typically achieve optimal removal at 500 mm/s using 100W systems with 12 J/cm² fluence. Basically, the 1064nm wavelength eliminates surface growth effectively while preserving the masonry, though deep root systems may require complementary treatments.
Q: How do different brick types (soft mud, pressed, engineering, fire) respond differently to laser cleaning?
A: Porosity dictates fluence tolerance. Soft mud bricks typically need a lower fluence around 12 J/cm² because of their high porosity, while dense engineering types can handle higher power. Always test refractory materials first, as their composition can fairly create thermal stress at standard 100W settings.
Q: Can laser cleaning effectively remove efflorescence salts from brick masonry, or will they quickly return?
A: Salts recur from porous substrate. Laser cleaning at 12 J/cm² pretty effectively removes surface efflorescence from brick. But without tackling the underlying moisture source, salts will typically return quickly from the porous substrate. For lasting results, pair this process with waterproofing treatments to block capillary moisture transport.
Q: What are the economic considerations when choosing laser cleaning over chemical or abrasive methods for large brick facades?
A: Preserves brick substrate integrity. Although the initial laser setup calls for some investment, its 500 mm/s scan speed basically delivers superior cost-efficiency per square meter over time. That 1064 nm wavelength preserves the brick substrate pretty well, dodging abrasive damage and pricey mortar replacement. Such selective cleaning cuts long-term maintenance cycles, yielding big economic gains for large-scale facades.
Brick Laser Cleaning Dataset Download
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