The dip/spin process is ideally suited for small parts that have contours so that the parts can be coated in bulk to prevent adhering to each other. Examples of such parts are: fasteners, spring clamps, screws, bolts, motor mounts, O-rings, nails, clips, muffler hangers, body mounts, etc.
Government regulations and product performance requirements are causing plating processes to be converted to coating processes. These regulations have practically eliminated the use of chrome, lead and other elements which are unfriendly to the environment.
In addition, component manufacturers must adhere to more stringent specifications which provide far higher salt spray performance and more consistent torque tension capabilities.
The answer is dip/spinning coatings onto parts that are pre-treated with a zinc-phosphate coating. Hi-Tech Coatings is authorized and license to apply a wide variety of coatings which will improve salt spray performance requirements and torque tension relationships. In addition, the dip/spin process significantly reduces the problem of hydrogen embrittlement.
The dip/spin process is a very cost effective process since it is a bulk process. The transfer efficiency of the coatings are upwards of 90 percent which is far superior to spray coating. PFG currently applies dry film lubricants, zinc rich coatings and molydisulfides using the dip/spin process.
The Dip/Spin Process
Parts are placed on a conveyor and then metered by weight into a 24" wire mesh basket. The basket (full of parts) is submerged into a coating vat. The basket is then raised out of the coating solution, yet still remains in the vat, and spun up to 600 rpm. The excess coating that is spun off is caught by the paint vat and reused.
Depending upon the application, the coating viscosity, temperature, spin velocity and curing time can be varied to provide the desired mil thickness and consistent repeatability. Once the process is developed, a specific process control data sheet can be assigned to the specific part to insure proven predictable performance.
The dip/spin process is a three step process for one coat and a five step process for two coats: