Case Study E

E-coat Paint Process Simulation using Finite element analysis

Case Studies
The following case studies are meant to be representative of the many different types of investigative work that can be accomplished by Finite Element Analysis (FEA) with the Parametric Module. These include examples from rocker panel design optimization to visualization of the E-coat paint process in operation.

Several PC work stations were used to create and run simulations for the case studies, including a Dual Intel Xeon 3.06 GHz PC with 4.5 GB RAM and an Intel Pentium 4 3.06 GHz with 1.5 GB RAM.

The typical elapsed time per iteration was related as a function of the total number of elements and the number of Boundary Conditions. The range of time required for one iteration varies from < 20 seconds for the simpler models to as much as ~25 minutes for the larger ones.

Case Study E:
Simulating the Painting Process to Determine a Price Quote

An E-coat job shop has been asked to prepare a quote on the custom coating of a new product. The E-coat painter creates an E-coat simulation that predicts how the parts will be racked, what the expected voltages are, and what the part-to-part variation might be so the cost of the coating can be accurately estimated.

Ware to be E-coated

Situation
Manufacturer has requested a quote for an E-coat job shop to paint this new part.

E-coat film thickness range is 15µ − 20 µ.

Model
The 3D FEA model was started from the manufacturer's Inventor drawing file and imported to the simulation program. A feaChamber™ was constructed that employed the standard E-coat tank geometry for the E-coat job shop. In addition, standard E-coat paint process conditions were also used.

E-coat Film E-coat   Thickness (microns) Mass volts Min Max Avg (grams) 160 12 16 14 1.617 200 16 19 18 2.079 240 18 22 19 2.195
Table of Results for various voltages	E-coat film thickness distribution (@ 200V)

Results
While the primary output of the simulation is the thickness of the E-coat film, the mass of the paint is also calculated as well. The table above shows the results for several simulation runs where the voltage was changed. The best voltage appears to be 200 volts since the minimum and maximum thickness are within the expected range.

Conclusions
The simulated mass of E-coat paint solids is ~2.1 grams per part. After choosing the best voltage level, the job shop painter can offer a price to the manufacturer that more accurately reflects the true variable cost. The simulation provided an easier method of analyzing the new product without wasting time and money creating a physical test model in the preliminary design stages.

Case Study A    |    Case Study B    |    Case Study C    |    Case Study D    |    Case Study E    |   Case Study F