How to Protect Your Fiber Laser Cutter in Cold Weather: Antifreeze Guide

As cold fronts sweep in and temperatures plummet—sometimes below freezing—it’s not just people who need protection; your precision fiber laser cutting equipment does too. Most fiber laser cutters use water-cooling systems, and if the coolant freezes, it can cause pipes and seals to crack, leading to serious damage to the chiller, laser source, or QBH output head. This risk is especially high for machines left idle or operating in unheated environments. In this guide, we’ll walk you through essential winter maintenance steps: anti-freeze methods, proper antifreeze usage, draining procedures, and safe startup protocols in low temperatures—helping you prevent costly downtime and ensure reliable operation all year round.

Cold Weather? Protect Your Fiber Laser Cutting Machine from Freezing

With the arrival of a cold front, temperatures have dropped sharply—almost without warning. While everyone should stay warm, it’s equally important to protect your fiber laser tube cutter from freezing during winter.

Fiber laser cutting machines use water cooling systems. When the liquid temperature falls below its freezing point, it solidifies into ice, which can easily damage cooling system pipes, seals, and connections. In severe cases, it may even destroy the laser source, QBH output head, or chiller unit. During cold winters—especially in northern regions where indoor temperatures can be very low—users must pay special attention to anti-freeze maintenance for their laser equipment.

Here are several key anti-freeze maintenance tips:

1. Run the chiller 24/7: Moving water is less likely to freeze.
2. Install air conditioning or heating systems to maintain an ambient temperature above 5°C, ideally around 10°C.
3. If the laser machine will be idle for a long time or during power outages, completely drain the water from the chiller and store the equipment in an environment above 5°C.
4. When temperatures fall below 5°C, add specialized antifreeze designed for laser equipment.

Antifreeze Usage Instructions

1. If there is any chance of temperatures dropping below 5°C, we recommend replacing the cooling water with pre-mixed antifreeze. If temperatures go below 0°C, antifreeze must be used. See the recommended mixing ratios below. (Image: Recommended Antifreeze Mixing Ratios)
2. When temperatures remain consistently above 5°C, completely drain the antifreeze, then flush the chiller multiple times with purified or distilled water. Finally, refill with standard purified or distilled water.

Recommended Mixing Ratios for Antifreeze Solution

Mixing ratios should be based on the local minimum ambient temperature.

Ratio (Antifreeze:Water)	Local Minimum Temperature
6:4 (60% antifreeze, 40% water)	-42°C ~ -45°C
5:5 (50% antifreeze, 50% water)	-32°C ~ -35°C
4:6 (40% antifreeze, 60% water)	-22°C ~ -25°C
3:7 (30% antifreeze, 70% water)	-12°C ~ -15°C
2:8 (20% antifreeze, 80% water)	-02°C ~ -05°C

How to Drain Water from the Chiller

1. Turn off all power before draining. Open the drain valve at the back of the chiller to empty the water.
2. Remove the inlet and outlet water pipes (label them clearly for correct reinstallation).
3. Unscrew the chiller’s filter cartridge and drain any remaining water inside.
4. Connect a 0.2 MPa (2 kg) air supply to one end of the water pipe to blow out residual water from the laser unit.

⚠️ Note: If using compressed air to assist drainage:

• Open all connection points (including the fill port) first.
• Blow air in from the inlet side only—never from the outlet.
• Use low pressure to avoid damaging the laser.
• Ensure all water is completely removed to prevent freezing damage to internal components.

Laser Equipment Startup Precautions in Winter (Water-Cooled Systems)

1. Only start the laser equipment when the indoor temperature is between 5°C and 35°C.
2. Check whether the water-cooling pipes are frozen. Do not power on the machine if ice is present.
3. If freezing has occurred, turn on air conditioning or heating to raise the ambient temperature to 5–35°C. Let the machine sit for at least 4 hours until the ice melts naturally. Never attempt forceful defrosting, as this may damage hardware.
4. Once you’ve confirmed no ice remains, turn on the chiller first to begin preheating.
5. Wait until the chiller’s circulating water reaches normal operating temperature (recommended: 25 ± 3°C) before turning on the laser source.
6. After normal startup, set the laser power to below 30%, perform a no-load beam test for about 10 minutes to warm up the system, then resume regular production.

Winter is a high-risk season for laser cutting equipment failures—especially those caused by frozen coolant, which often lead to expensive repairs and production delays. By taking proactive measures—such as keeping the chiller running, adding heating systems, replacing water with antifreeze, or fully draining the system—you can prevent over 90% of cold-weather-related damages. Additionally, strictly following pre-startup checks and warm-up procedures ensures safe and stable operation. We hope this anti-freeze maintenance guide helps you and your team get through the winter smoothly, extending your machine’s lifespan and improving production reliability. Remember: Prevention is better than repair—a small maintenance step today could save a major loss tomorrow.