The typical process of E-Coat Equipment pretreatment comprises of at least 12 stages. The first five stages include car wash, deluge, rinse, spray cleaner, and dip cleaner. These enumerated five stages clean the vehicle body by removing the oils as well as dirt before painting or coating the vehicle. These stages are then followed by a conditioner stage, five rinsing stages and phosphate stage before the process of electrocoating application. All of the aforementioned pretreatment stages are outfitted with the use of the filtration equipment and the primary objective is to provide three up to four tanks per hour with the use of the equipment.
However for many facilities, the cleaning processes are not really as effective as they should be. There are several problems that arise like the buildup of solids as well as oils in the cleaner stages and the inconsistent cleaner chemistry. Another thing is the insufficient dwell time devoted in the cleaning stages as well as the ineffective filtration cause oil, dirt and other contaminants to enter the subsequent stages of pretreatment. In one analysis of the cleaner, deluge, DI dip stages and rinse, dirt was indeed present in the bags used to filter the materials in different stages tested. Oil on the other hand was also discovered in the filtration bags of all of the stages which were tested and the largest amount of contaminant were found in the cleaner dip filtration bag. Additionally, the sealer was very much present in the filtration bags of stages 1 and 3 just before the process of e-coat.
Looking at the problem closely
An analysis conducted in the pretreatment system would indicate that a significant amount of the contaminants exist in the process like dirt, rust, oil, weld balls and sealer. These contaminants would need to be removed effectively in order to maintain the production of great quality vehicle. Most facilities will refresh their tanks at different pretreatment stages on a scheduled basis in order to reduce the buildup of various contaminants like oils and solids inside the tank but this is neither an environmentally friendly nor is it efficient. On the average, automotive plants will use about 180 million gallons of water annually with about 75 to 80 percent of the entire materials used in the paint operations. An important portion of the water used by operators of paints is used in pretreating the method. Although reduction in the water usage is being made with the use of varied techniques like counterflowing fluid before the stages in the process, these methodologies will save both chemicals and water as needed.