Micro molding is a type of fabrication process that creates detailed structures in polymers on a micro scale using molds. The micro molds are made in a micro-tooling department where a cavity is carved into each mold that matches the shape of the part to be manufactured. The component or item can then be swiftly created by the micro-injection molding process. Here, thermoplastic or resin is injected into the cavity at a high speed.

When making micro parts, one factor to consider is “micro tolerance.” This refers to the minimal distance between the required measurements and design size that must be met in order for the micro component to be utilized. The concept assesses whether the margin of error is narrow enough to still work.

The stack-up tolerances must be within 1/100th of an inch in a micro molding process, though in certain situations the molded component must be within 1/1000th of an inch. Traditional injection molding can frequently produce small fragments that do not require such tight tolerances.

With traditional or conventional molding, it’s difficult to manufacture microscopic parts that measure less than a millimeter across. However, with micro-mold-enabling technology and specialized micro machining, we can create highly intricate and detailed plastic components at any size needed!

The Difference Between Micro Molding and Traditional Injection Molding

The procedure for micro-injection molding appears to be similar to conventional injection molding. A mold design and prototype are made, followed by the creation of a double-sided mold. However, there is a difference between the two injection molding processes.

Conventional injection molding is the process of forcing thermoplastics into a mold. Thermoplastic materials are melted in a furnace and then injected with a highly pressurized injection tool. When the molded parts have cooled and hardened, the item is removed.

Micro molding can be completed in the same way as conventional molding, but with a different micro-injection unit (built in the machine) necessary to accommodate the micro components.

Micro Molding Materials

Micro molding is often carried out with thermoplastics, thermosets, polymers, resins, and elastomers. Fortunately, there is a plethora of molding materials to select from when making micro molded parts. It is feasible to make a mold that is smaller than a dime by picking the appropriate material for the item you have in mind.


In many situations, handling and packaging seem to be an afterthought, but in reality, they’re often as essential as producing the part. Handling and packaging micro-sized devices is significantly more difficult than handling and packing macro-sized components, and the solutions are different. Molding and packing micro items so that they are useful to the end user is an important aspect of production.

Custom automation and packaging services may be provided in a variety of ways. They might range from reel-to-reel packaging to light subassemblies, high-speed automated packaging, lead frame die-forming and singulation, in-line automation, and a wide range of other packaging processes. These services go a long way to determine the success of a project.

How Extensively Is Micro Molding Used Across Industries?

Micro molding is used across several industries. It has become an important part of the manufacturing of numerous essential devices that make the modern world work.

In a lot of procedures in today’s medicine, such as minimally invasive surgery, precision is required. As a result, many medical equipment items must be tiny and highly sophisticated. Medical device manufacturing, therefore, relies heavily on micro molding processes.

There’s also a higher demand for high-precision, sophisticated work in the engineering industry. This is because modern electronic devices are getting much smaller and need tiny parts with extremely tight tolerances. Micro molding advantages may be applied to a variety of electronic component manufacturing such as micro-optics, hair-sized core pins, and so on.

These are just a few examples of industries where micro molding processes have became a critical factors.

For all your micro molding or other custom molded urethane and rubber products, reach out to Uniflex. Our company has specialized in custom molded urethane and rubber since 1979, and is a trusted supplier for the aerospace, automotive, robotics, military, oil, gas, mining, and marine industries. We have the ability to design, machine, and manufacture all under one roof, which helps keep prices low and lead times short. Request a quote online or call us at 248-486-6000 to speak with one of our dedicated team members about your order.