Laser Cleaning Process Parameters For Molds Of Different Materials
Steel has low thermal conductivity and high temperature resistance; aluminum and copper have high thermal conductivity and high reflectivity, are extremely prone to heat absorption and oxidation, and exhibit localized blackening due to melting pits. Therefore, these three materials cannot share the same parameters. The parameters described herein are suitable for 1000W/1500W/2000W pulsed fiber optic cleaning machines, and are compatible with specialized processes involving cavities, deep textures, and fine venting grooves. They are also suitable for injection molding, die casting, and rubber mold maintenance.
Table of Contents
Hardened steel/plastic steel/hot work steel molds
Material characteristics: High melting point, poor thermal conductivity, moderate laser reflection of the substrate; nitrided/chrome-plated layers are susceptible to discoloration under high heat; can withstand relatively high energy densities; the easiest mold material to control.
Uncoated bare steel molds
| Dirt Level | Total output power | Pulse frequency (kHz) | Scanning speed (mm/s) | Key points of the process |
|---|---|---|---|---|
| Slight carbon buildup, thin oil stains | 1000W ：40%~50%1500W：32%~42%2000W：25%~35% | 40~60 | 350~450 | Single uniform speed sweep, standard planar gun movement |
| Medium-cured mold release scale | 1000W：60%~70%1500W：45%~55%2000W：38%~48% | 30~45 | 280~350 | Two-stage layered cleaning, deep tank inclined side sweep |
| Heavy carbonization / die casting oxide scale | 1000W 1500W：70%~85%2000W：55%~70% | 20~30 | 180~260 | Perform 3-4 thin-layer cleanings, avoiding lingering in one spot. |
Chromium-plated/ion-nitrided steel mold
Overall power is reduced by 20%~30% from the bare steel base, frequency is increased by 10~15kHz, and speed is increased by 80~120mm/s; stubborn stains are removed by multiple thin-layer peelings with low power (3~5 times), and high-power one-time bombardment of the coating is strictly prohibited.
Aluminum alloy mold
Material characteristics: High thermal conductivity, high reflectivity, low melting point (660℃), extremely prone to localized overheating causing white spots, melting pits, and grain boundary oxidation; high reflectivity easily reflects laser light, damaging equipment lenses; strict control of heat accumulation throughout the process is necessary, prioritizing high frequency, high speed, low power, and multiple thin scans.
Aluminum mold full range parameters
| Dirt Level | Power ratio | Pulse frequency (kHz) | Scanning speed (mm/s) | Special Operations |
|---|---|---|---|---|
| Light oil stains and thin carbon deposits | 1000W：28%~35%1500W：22%~30%2000W：18%~25% | 70~90 | 500~650 | Two cleaning cycles, large light spot size 2.5~3mm |
| Medium-cured mold release scale | 1000W：38%~45%1500W：30%~38%2000W：24%~32% | 55~70 | 400~520 | Three layers were applied, and the slots were replaced with 1.0mm smaller spot sizes, resulting in a 10% power reduction. |
| Heavy aluminum dross + thick carbon deposits | 1000W：55%~65%1500W：42%~52%2000W：35%~45% | 40~55 | 300~380 | Perform 4-5 intermittent cleaning cycles (with a 20-second interval between each cycle to allow for heat dissipation). |
Copper/Beryllium Copper Mold
Material Characteristics: The most difficult to clean of all types; its thermal conductivity is 8 times that of steel; it has extremely high laser reflectivity; its melting point is 1083℃; heat is instantly conducted deep into the surface, making it extremely prone to localized melting and surface blackening/pitting; its power consumption under all operating conditions is 50%~60% of that of steel molds of the same thickness; it operates at full high frequency, ultra-high speed, and multiple thin-peeling passes. Full power operation is not recommended for copper molds.
Copper Mold Full Range Parameters
| Dirt Level | Power ratio | Pulse frequency (kHz) | Scanning speed (mm/s) | Process Details |
|---|---|---|---|---|
| Thin layer of oil and carbon float | 1000W：18%~25%1500W：15%~22%2000W：12%~18% | 80~100 | 650~800 | Three passes of low-speed, thin-layer cleaning, with a light spot size of 2.5mm. |
| Moderately cured carbon deposits | 1000W：28%~35%1500W：22%~30%2000W：18%~25% | 65~80 | 520~650 | Four layers were applied, the light spot size in the exhaust slot was 0.8mm, and the power was reduced by 10%. |
| Severe sulfidation/carbonization | 1000W：40%~50%1500W：32%~42%2000W：28%~35% | 50~65 | 420~500 | Perform 5-6 intermittent cooling and cleaning cycles; do not continuously spray the same area. |
Precautions for copper molds:
Start with 10% of the rated power for the first test run and gradually increase it;
If the copper surface turns black, immediately stop the machine and allow it to cool for 3 minutes;
If the surface is severely reflective and cannot be cleaned, a 532nm green laser can be selected to improve the absorption rate.
Conclusion
Steel mold: Medium power, low to medium frequency, moderate speed; power can be increased for thick deposits.
Aluminum mold: Low power, high frequency, fast speed; multi-layered sweeping prevents white spots.
Copper mold: Ultra-low power, ultra-high frequency, fastest speed; small-batch, multiple sweeps prevent melting pits.
We provide free mold sample cleaning test for steel, aluminum, copper molds, customize exclusive laser parameters according to your dirt thickness and cavity structure. Contact our technical team to get detailed parameter sheet.