As technology now allows manufacturers to create really small parts using injection molding, micro molding is quickly becoming a niche industry. Inventors and manufacturers alike have an increased interest in producing highly precise and consistent micro-featured plastic parts. So, what exactly is micro molding and why is it on the rise in demand?
What is Micro Molding?
Micro molding is a specialized type of injection molding. Injection molding is a manufacturing process in which parts are made by injecting plastic into a mold. Not just any type of plastic will do however. A special type of plastic, called thermoplastic, is required. Thermoplastic comes in two forms; it is manufactured in the form of tiny, colored pellets or in long, thin strands on a spool. The process is the same, however, no matter which form is used. The thermoplastic is fed into a barrel, heated until it is melted, and then shot into a mold. When the plastic cools, it conforms to the shape of the mold and hardens. After the plastic part is removed from the mold, it is then trimmed and/or sanded to make it smooth. Micro molding, then, is a type of injection molding in which tiny parts are made.
Why is Micro Molding is in Demand
Micro molding is popular for three main reasons. First, the size is impressive. Micro molding can create detailed parts that weigh a milligram. Let’s put this in perspective. A paper clip, a feather, and the United States’ dollar all weigh approximately one gram. A milligram is 1/1000 of a gram. So, what types of things weigh a milligram? A worker honeybee’s brain weighs approximately one milligram. The typical raindrop weighs around thirty milligrams. One kernel of popcorn weighs about sixty milligrams. So, it is simply amazing that technology now permits the injection molding of such tiny parts.
Micro molding is precise. The technology is so precise that barely visible gears actually work. When you think again about the process – heated thermoplastic being shot into a mold – you realize how amazing this high level of precision actually is.
Last, but not least, micro molding virtually microscopic parts can be molded with two different materials at the same time. Both materials are shot into the molds at the same time which means only one mold cycle is needed for two materials. This saves time and labor, which, in turn, saves both the designer and manufacturer money. It also increases the aesthetic of the part, as well as its functionality.
