Automotive E-Coat Paint Process Simulation Using FEA
Finite element analysis (FEA) is widely utilized in the automotive industry to study a variety of engineering design activities such as crash test simulations and optimization of manufacturing processes. One of the latest areas to benefit from FEA technology is the E-coat paint process. E-coat paint provides for excellent corrosion resistance and is the first of several different protective paint layers applied to an automotive body. During the E-coat paint process, an entire automotive body is immersed in a liquid bath. By applying an electrical current, a thin paint film forms over all the surfaces in contact with the liquid, including those surfaces in recessed portions of the body.
The E-coat paint process deposits a thin paint film on the automotive body under the influence of a voltage gradient of about 200 to 300 volts. The water-based E-coat paint bath is conductive with an array of anodes that extends into the bath delivering a DC current. The paint film that forms has physical properties that resist corrosion (these appear only after the automotive body has been cured in an oven). However, as the paint film forms, its electrical resistance increases.
In the past several years, two-dimensional (2-D) FEA models of the E-coat paint process have been developed for specific or limited applications. In this paper, we discuss a general three-dimensional (3-D) FEA method using ALGOR software. This method can simulate the formation of the E-coat film and can thus predict its thickness at any point on the surface of the automotive body. Operational variables, such as voltages and process duration, are used to simulate the time-dependent interaction among the automotive body, the increasing paint layer and the liquid within the E-coat bath.
The method is based on a quasi-static technique that accounts for the changing material properties of the paint layer. A quasi-static approach is appropriate because the time required for the electric field to be established
The E-coat paint process deposits a thin paint film on the automotive body under the influence of a voltage gradient of about 200 to 300 volts. The water-based E-coat paint bath is conductive with an array of anodes that extends into the bath delivering a DC current. The paint film that forms has physical properties that resist corrosion (these appear only after the automotive body has been cured in an oven). However, as the paint film forms, its electrical resistance increases.
In the past several years, two-dimensional (2-D) FEA models of the E-coat paint process have been developed for specific or limited applications. In this paper, we discuss a general three-dimensional (3-D) FEA method using ALGOR software. This method can simulate the formation of the E-coat film and can thus predict its thickness at any point on the surface of the automotive body. Operational variables, such as voltages and process duration, are used to simulate the time-dependent interaction among the automotive body, the increasing paint layer and the liquid within the E-coat bath.
The method is based on a quasi-static technique that accounts for the changing material properties of the paint layer. A quasi-static approach is appropriate because the time required for the electric field to be established