1. Introduction
As an essential tool in modern manufacturing, molds are widely used in metal casting, plastic injection molding, rubber compression and glass forming. However, during long-term operation, molds are exposed to high temperatures and repeated contact with materials, leading to contamination such as oil residues, oxides, burnt polymers, carbon deposits, release agent residues and corrosion layers. If these contaminants are not removed efficiently, they will cause product defects, dimensional deviations, surface quality issues, or even accelerate mold wear.
Traditional mold cleaning methods such as sandblasting, manual chemical cleaning, and dry-ice blasting present drawbacks including substrate damage, residual contamination, high downtime costs, and environmental burdens. In recent years, laser cleaning has emerged as an efficient, precise, and non-contact surface treatment technology in the mold industry, offering distinct advantages.
2. Technical Principle of Laser Cleaning
Laser cleaning utilizes a high-energy laser beam focused onto the mold surface. The contaminants absorb the laser energy and undergo vaporization, thermal decomposition, or brittle detachment, while the metal substrate remains unaffected due to its high reflectivity and thermal conductivity. The process requires no chemical additives and causes no mechanical abrasion, making it a purely physical cleaning approach.
Key characteristics include:
Selective removal: contaminants absorb energy while the substrate reflects it
Instantaneous action: layers are decomposed and detached rapidly
High precision: beam spot can reach micron-level diameters
No secondary pollution: residues are mainly dust or collectable particles
3. Advantages in Mold Industry Applications
(1) No Substrate Damage & No Dimensional Impact
Molds require strict control over dimensional tolerance, surface roughness, and texture integrity. Laser cleaning is a non-contact thermal process that:
Avoids abrasion from sandblasting media
Prevents chemical corrosion from solvents or acids
Preserves surface textures and microstructures
Thus, it is suitable for precision molds, mirror-polished molds, and coated molds.
(2) No Chemicals Required, More Environmentally Friendly
Conventional chemical cleaning uses solvents and acidic or alkaline solutions, which corrode molds and require wastewater treatment. Laser cleaning offers:
No chemical consumables
No volatile organic compounds (VOCs)
Minimal waste discharge
Dust removable via extraction systems
It complies with environmental regulations and green manufacturing standards, especially in food packaging molds and medical-grade molds.
(3) On-line Cleaning, Reduced Downtime
Traditional cleaning often requires mold disassembly, cooling, transfer, and soaking, resulting in significant downtime. Laser cleaning enables:
Localized on-line cleaning without removing the mold
Minimal thermal influence, no extended cooling time
Faster production recovery, lower idle cost
This is particularly beneficial for injection molding where release agents tend to carbonize during repeated cycles.
(4) Stable and Repeatable Cleaning Results
Laser parameters (pulse energy, frequency, scan speed, spot size) are adjustable, enabling consistent industrial performance:
Thorough cleaning without blind spots
Repeatable results independent of operator skill
Elimination of defects such as streaks, black spots, or gas marks
It enhances mold consistency and final product appearance quality.
(5) Wide Applicability Across Mold Types
Laser cleaning can handle various types of contaminants on molds, including:
Injection molds: burnt polymers, release agent residues
Rubber molds: vulcanized carbon layers
Die-casting molds: oxides, lubricants
Stamping molds: rust and oxide layers
Compatible mold materials include tool steel, aluminum alloys, chrome-plated surfaces, nitrided surfaces, etc., covering industries such as automotive, 3C electronics, medical, food packaging, and home appliances.
4. Conclusion
With its non-destructive, eco-friendly, automated, and high-efficiency characteristics, laser cleaning is rapidly becoming a preferred technology replacing traditional mold cleaning processes. As equipment costs decrease and intelligent control systems mature, the application scope will continue to expand, offering manufacturers a more reliable, economical, and sustainable surface treatment solution.