Dip coating and dip molding are advantageous for some manufacturers because their concepts are simple and flexible, offering a variety of advantages.
Provide accurate internal dimensions
Since no shrinkage occurs during these processes, the required internal dimensions can be obtained exactly. Compared to other types of molding methods, cooling rate is not a critical parameter that needs to be controlled.
Produce durable parts
Dip coating and dip molding easily produce seamless, two-layer parts. The seams created by connecting two parts create stress points that greatly increase the durability of the part.
Limited restrictions on product size and design
With dip casting, large plastic parts can be made by using dip molding to surround large metal pieces. If similar large plastics were produced using an injection or blow molding process, large molds would be required; and become an expensive operation. The only limitations to dip molding are the size of the tool, the capabilities of the preheating and curing oven, and the capacity of the polymer solution tank. Dip coating and dip molding also have the ability to form complex designs with severe undercuts and corners.
Ease of modification and variability in product design
Because mold materials are easily modified, designers can easily add additional details to the final product. Different coating materials and thicknesses can be produced with the same mold, depending on the formulation of the polymer solution.
Low operating and investment costs
Dip coating and dip molding are ideal for short-run orders and lab-scale production because these processes involve a simple set of equipment, unlike injection molding and blow molding, which require complex machines and large amounts of floor space. In addition, it does not work under high pressure, and the dipped mold is also very cheap.
Reduce polymer material waste
In dip coating and dip molding, excess solution drips back into the dip tank, making it ready for reuse. In other types of molding, excess polymer material appears in the form of cuts and runners that require additional processing to be recycled. Dip coating has advantages over spray coating. In contrast to the spray method, some of the spray paint is transferred to the surrounding walls of the coating room or equipment and is wasted.
However, there are some limitations when using these processes, while other molding methods have advantages. Here are the disadvantages.
Difficulty obtaining accurate external dimensions
Although the resulting internal dimensions are accurate, it is difficult to obtain precise coating thickness because it depends heavily on many variables: residence time, temperature of the mold, speed of immersion, withdrawal of the mold from the polymer solution out and the properties of the polymer solution. This also makes good coating thickness distribution difficult to achieve.
Time consuming
Dip molding is a slow process as it requires long cycles of heating, dipping and cooling.