Enhance Paint Drying Efficiency with Carbon Fiber Heating Elements

In the initial stages of production, many people believed that the drying mechanism of paint coatings is similar to that of drying wet materials, which is primarily a heat transfer process unrelated to chemical changes, purely a process of thermal transmission. However, further research has revealed that besides the pure physical process of converting thermal radiation into heat energy within the paint layer, chemical reactions also play a crucial role, especially in thermosetting paint films.

The curing process of paint coatings can be divided into two stages: diffusion stage and curing stage. The diffusion stage involves the input of thermal radiation into the coating, mainly preheating and warming up the workpiece and the evaporation of sufficient volatiles. The curing stage, also known as the kinetic stage, is where chemical bonds are actively cured. Effective temperature control is crucial during this stage, as the rate of chemical reactions dictates the progress of the drying process. According to the laws of chemical kinetics, increasing the temperature by 10°C can accelerate the chemical reaction rate by 1-3 times.

Research conducted at a university validated the use of carbon fiber heating elements with a surface temperature of around 600°C. Placed 10 cm away from the heating element, these elements irradiated the surface of automotive steel rim paint with infrared rays for 3 minutes, achieving drying effects equivalent to those obtained in traditional factory ovens in 30 minutes. Consequently, countries like the United States and Australia have adjusted their automotive steel rim production processes to adopt directional infrared radiation heating, reducing the heating cycle to 10 minutes and significantly conserving electrical energy resources.

For automotive steel rim paint, which predominantly uses acrylic clearcoat paint with its strongest absorption peak at 600°C, employing carbon fiber heating elements corresponding to this surface temperature maximizes the utilization of infrared radiation. Comparative experiments between carbon fiber heating elements and conventional drying methods yielded the following results:

1. Factory Using Resistance Strip Radiators
   • Installation power: 256 kW
   • Drying cycle: 30 minutes
   • Length of drying channel: 30 meters
   • Surface humidity after drying: 6%-7%
2. Using Carbon Fiber Heating Elements at 10 cm Distance
   • Drying cycle: 2 minutes
   • Surface temperature after drying: 151°C
   • Surface humidity after drying: 6%-6.8%

The experimental results demonstrate that using carbon fiber heating elements as infrared radiation sources for drying acrylic paint coatings significantly reduces drying times and enhances drying efficiency.

A Chinese automotive company replaced its hot air circulation drying channel with an infrared directional radiation drying channel. This modification reduced the installed capacity from 288 kWh to 216 kWh, decreased the drying cycle from 30 minutes to 25 minutes, and lowered overall equipment power consumption. Despite the costs of equipment modification being offset against electricity savings and increased production efficiency, the benefits are substantial.

GlobalQT is a leading manufacturer of carbon fiber heating elements, offering efficient infrared heating solutions. For more information, visit our vefsíðu eða hafðu samband við okkur á contact@globalquartztube.com.