The Effect of Oven-Heat Flux on Powder-Coating Issues of Sheet Molding Compound Panels

Abstract

The effects of variations in the powder bake temperature profile on the paint popping defect of sheet molding compound (SMC) panels was investigated by subjecting powder-coated panels to various heating rates using IR heaters and convective ovens, and by using a mathematical model of heat transfer and curing reaction. It was found that overheating the SMC than that required for optimum powder curing can cause high rates of outgassing of absorbed moisture and, therefore, excessive popping. It was further found that higher quantity of moisture outgassing per unit time through the molten primer layer during a fast temperature ramp causes more popping compared to a slow temperature ramp. Therefore, it is expected that any plant that is experiencing paint popping would benefit from slowing down the rate of temperature rise of the panels during the initial 5−10 min of the heating cycle.

A numerical simulation of a line-type paint drying furnace

“…A line-type paint drying furnace among the various types of drying facility is widely used in the mass production system in many industries such as automotive, food, and chemical industries because this line-type paint drying furnace is best for mass production with a shorter drying process time. However, the line-type drying furnace can exhibit a lower painting quality compared to a stationary infrared light oven (Basu et al , 2009; Blanc et al , 1997; Dufour et al , 2004) or a hybrid oven with infrared light and convective equipment (Drying paint faster, 2001; Parrouffe et al , 1997) because the process can be terminated before the paint film is dried to a satisfactory level for the next process because of the limitations in line length. When the natural drying type paint is used, this half-drying problem is much more severe.…”

Synthesis, Characterization and Antimicrobial Screening Mixed-Ligand Cu(II) and Zn(II) Complexes; DNA Binding Studies on Cu(II) Complex

“…In this regard, mixed-ligand metal complexes were found to be particularly useful because of their potential to bind DNA via a multitude of interactions and to cleave the duplex by virtue of their intrinsic chemical, electrochemical, and photochemical reactivities [3][4][5][6][7][8][9]. A singular advantage in the use of these metallo-intercalators for such studies is that the ligands or the metal ion in them can be varied in an easily controlled manner to facilitate individual applications [10,11]. although DNA interactions of number of mixed-ligand complexes previously appeared in the literature, there is still scope to design as study Schiff base with metal salt as new chemical nucleases.…”