Dip coating is a production approach that involves the application of some type of protective coating onto the finished product. The main function of this process is to increase the useful life of the product, although it may also be used for decorative purposes as well. Products that are routinely subjected to dip coating are found in both the home and in the workplace.
The most common form of dip coating involves covering metal with plastic. A good example of this type of application is the simple wire hanger. In order to protect clothing from the possible development of rust on the bare metal of the hanger, the hangers are coated with a thin layer of plastic. The plastic protects the metal from exposure to the open air and limits the possibility of rust. At the same time, the protective coating prevents direct contact between the fabric of the clothing and the metal, and thus minimizes the chances of some sort of stain developing on the material.
In actual practice, the process of dip coating is not difficult. In fact, it can be broken down into a simple three-step process. First, the object is cleaned thoroughly and the immersed in a vat or container of the hot plastic. By immersing the object, there is a better chance of achieving an even coating all along the surface of the product.
Once the object is immersed, the next phase of dip coating involves determining how long to leave the object in the hot plastic. This is known as the dwell time. Depending on the construction of the object and the type of melted plastic in use for the coating, the dwell time may vary anywhere from a few seconds to several minutes.
The final phase of this process is known as the withdrawal cycle. This involves methodically removed the object from the hot plastic. Care is taken to remove the object as a constant rate of motion. This helps to minimize the chances for the development of judders along the surface of the object. The actual speed helps to determine how thick the final coat dip coat actually is. Generally, faster withdrawal from the plastic will result in a thicker coating along the surface of the object.
Dip coating is often added as a protecting coat to electrical wiring and other items that need to be insulated for safety purposes. At other times, the coating may be used to add color to the finished product, making it more visually appealing. In both situations, the presence of the coating usually extends the life of the object, allowing consumers to enjoy more of a return for their investment in the product.