2. Spray blowing process parameters

1) The blowing pressure should be matched with the diameter and length of the capillary tube, ensuring strong blowing and sufficient combustion, while preventing any incompletely burned deoxidizer from being blown away by the airflow from the capillary tube.  

2) The blowing time should be adjusted according to the direct and length of the capillary tube, with the standard being that there is no suspended metal oxide in the capillary tube before it is blown out.  

3) The nozzle height should be adjusted according to the diameter of the capillary tube to ensure good alignment. Each shift needs to clean the nozzle once, and if the machine is stopped for a long time, the nozzle should be removed for cleaning. To ensure uniform blowing of the oxide removal agent on the inner wall of the capillary tube, an optional device is used at the spraying station for the oxide removal agent, accompanied by a rotating air pressure.  

3. Core rod lubrication

Poor lubrication effect of the core rod or low temperature of the core rod lubricant can cause internal scarring. To increase the temperature of the core rod, a method of cooling with only one cooling water can be adopted. During the production process, it is necessary to strictly control the temperature of the core rod to ensure that the surface temperature of the core rod is between 80-120 ℃ before spraying lubricant. The core rod temperature cannot be higher than 120 ℃ for a long time to ensure that the lubricant on its surface is dry and dense before pre threading. The operator should regularly check the lubrication condition of the core rod.