When the air temperature is lower than zero ℃, the liquid water will condense into a solid, and during the solidification process, the volume will become larger, which will "crack" the pipes and components in the water cooling system of the fiber laser cutting machine (the cold water system includes the chiller, the laser and the output head). How to avoid laser frostbite is the key problem of maintaining optical fiber cutting machine in winter.

（1） Add professional brand antifreeze into the water cooler, such as AntifrogenN antifreeze from Clariant, with the proportion of 3:7 (3 for antifreeze, 7 for water). After adding antifreeze, it can resist minus 20 degrees Celsius without freezing. If the temperature is lower than this range, please consult the chiller supplier to confirm the antifreeze proportion.

If it is not convenient to purchase professional brand antifreeze, you can purchase large bottles of automotive antifreeze Shell OAT-45 ℃, which is directly used in the water-cooling system of the optical fiber laser cutting machine. Due to the use environment and the configuration of the water cooler, please contact the manufacturer of the laser cutting machine for technical support in case of abnormal temperature during use.

Any antifreeze cannot completely replace deionized water and cannot be used for a long time all year round. After winter, the pipeline must be cleaned with deionized water or purified water, and the use of deionized water or purified water as coolant must be resumed.

（2） Please drain the water in the relevant pipeline of the optical fiber laser cutting machine during holidays such as the Spring Festival holiday or long power outage.

The specific operation method is as follows:

1. Turn off the power supply of the chiller and the laser, unplug the corresponding power plug or disconnect the switch;

2. Disconnect the water pipe of the laser and drain the water into the empty bucket naturally;

3. Blow compressed air from one end of the water pipe (the pressure is not more than 0.4MPa or 4kg) for auxiliary drainage. After the first drainage, it is recommended to repeat this step at least twice every 10 minutes to ensure that all residual water inside is drained;

4. The output head and processing head of the laser, as well as the cooling water in the middle pipe, shall be drained according to the above method; The cooling water inside the water cooler should also be drained. Consult the fiber laser cutter manufacturer for specific methods.

5. After the water is drained, the output optical cable head shall be filled with antifreeze and short circuited with a hose.

Optical fiber cutting machine equipment is an important productivity and valuable asset of our enterprise. Careful maintenance can help us make better use of it, and it will also create more value for us.