Motor housings, gearbox bodies and water pump parts mostly use cast iron or aluminum castings. Castings have porous, complex surfaces and require high coating adhesion and anti-rust performance. E-coating can penetrate the inner cavity of castings and provide a uniform, dense protective film. Taizhou Yufeng Intelligent Equipment Co., Ltd. designs e-coating lines for casting products.
E-coating characteristics of castings
Castings have rough surfaces with micropores. Pretreatment must fully remove oil and rust so that residues do not affect adhesion. During e-coating, the porous structure of castings helps the paint penetrate and form a good anti-corrosion film. After e-coating, baking cures the film and improves density. For cast iron parts, anti-rust performance is the main evaluation indicator of the coating.
Rack and hanging design
Castings are heavy and irregularly shaped. Rack design considers convenient hanging and uniform e-coating. The number of contact points between the rack and workpiece is reasonable to ensure current conduction and film uniformity. The rack uses materials with good conductivity and is cleaned regularly to remove paint accumulation. Hanging density is optimized while ensuring quality to increase output per tank.
Bath and film thickness control
E-coating bath parameters such as solid content, pH, temperature and conductivity affect film thickness and appearance. The system is equipped with circulation, filtration and temperature control devices, and the bath is inspected and replenished regularly. Voltage and current are set by product, and film thickness is controlled through online inspection and periodic sampling. The ultrafiltration system recovers rinsing water and reduces wastewater.
Testing and quality verification
E-coated castings undergo film thickness, adhesion, impact and salt spray tests. Cast iron parts focus on salt spray corrosion and impact performance, and aluminum castings focus on adhesion. Test data is bound to the product number to form a quality file. Non-conforming products are reworked according to the process.
Project services
We provide solution design, equipment manufacturing, installation and commissioning and training for motor gearbox and water pump e-coating lines. When planning, provide the product material, size, output and coating requirement. We design the tanks, racks, power supply and environmental facilities.
For a motor gearbox and water pump e-coating line proposal, contact Taizhou Yufeng Intelligent Equipment Co., Ltd. for a technical evaluation.