Micro-Injection Molding: Process and Benefits Explained

Micro-injection molding is a highly specialized manufacturing process that offers micro-sized and précised thermoplastic parts with tolerance in microns or sub-microns. The whole process of micro molding starts in a tooling department.

A micro-structured mold made up of aluminum or steel is prepared (CNC machined or EDM machined) with a cavity in the shape of the part that needs to be designed. The thermoplastic or resin gets directly and promptly injected into the cavity, and the component gets ready at high speed.

The principal distinction between micro-injection molding and conventional molding is the precision and the shot size of injection molding machines. Micro molding uses smaller and micro-featured molds, cores, and cavities as well. Moreover, the micro-injection molding process needs broader regard for packaging and QC (quality control) measures.

When is Micro-Injection Molding Used?

The following are the situations when micro-injection molding gets used:

1. Low-Volume Manufacturing

Micro-injection molding is suitable for low-volume manufacturing or even prototyping. It is because of reduced tooling and operating costs, which makes low-volume production possible at low budgets. The reason for reduced operating and tooling expenses is that the molding machines are smaller.

In addition, the micro mold used in micro-injection molding usually gets made up of aluminum, which is less expensive, faster, and flexible for small changes in designs.

2. Small Parts Needed

Micromolding might be considered the most instrumental factor when it is about the manufacturing of small but highly précised components or parts.

Usually, the final products attained using micro molding weighs around 10 to 0.1 grams, and the tolerance remains between 10 to 100 microns. These small-in-size parts get commonly used in high-profile applications like aircraft, electronics, medical and healthcare, and automotive industries.

Benefits of Micro-Injection Molding

Amid a lot of benefits of micro-injection molding, here are some of the most significant ones:

1. Manufacturing Costs Reduction

As compared to conventional injection molding costs, the cost of micro molding is much lower. The tools required and used in the micro-injection molding are more diminutive and available at a low price. For example, smaller and less expensive machines are required for reduced clamping force. If compared with the full-priced tool, the cost of micro-injection molding is around 40% down.

Simultaneously, micro molding involves much shorter cycles than the traditional plastic injection molding process, which massively helps in reducing the costs of production. Micro molds made up of aluminum bring about faster and inexpensive machining. Typically, compact barrels, fewer mold cavities, small-sized runners also play a pivotal role in reducing the cost of the process.

2. Plastic Waste Minimization

The foremost factor that considerably reduces plastic waste in the micro molding process is that the process is related to the manufacturing of small-sized products and consumes less raw material. For instance, shorter runner systems help minimize the waste compared to conventional injection molding.

Usually, the product’s design is not extraordinarily complex, so the chances for wastage are less evident. However, another reason includes consuming the leftover raw material in runners, gate systems, and barrels. In traditional injection molding, the leftover in gateway systems and barrels goes to wastage. But the wastage is brought to use in micro-injection molding.

3. Flexibility Assurance

The molds used in micro molding are usually made up of softer materials like aluminum. The micro-injection molds made up of any softer material conveniently allow designers to introduce changes and improvements in the existing design of the product.

The reason is that this kind of material offers faster and lower-cost mold machining. Due to this facility of easy modifications, the applications of micro-injection molding are considerably expanding.

4. Shorter Time to Market

The parts and components made using micro-injection molding have a shorter lead time. First, the size of the parts is small, so their manufacturing takes little time, offering faster cycles. Secondly, micro molding machines have compact and short-length barrels that quickly transfer the molten material into the mold, where it gets solidified.

Even multi-cavity micro-injection molds can get cycled faster than their counterparts larger in size using the micro molding process. Due to these reasons, the time to market the micro-injection molded parts is shorter. It can be said that micro-injection molding is one of the critical processes leading towards rapid injection molding. It plays a crucial role in being successful in a saturated and competitive market landscape.

Conclusion

Conventional plastic injection molding is a valuable process. Still, it might not be suitable for specific applications, and micro-injection molding is a glaring example of this fact.

By now, micro-injection molding has started sharing a considerable portion of the revenue generated by plastic molding, and the streamlining of this process has eased and précised the production of parts with small sizes. While having huge applications and benefits, micro-injection molding has become part of almost every industry, especially for high-profile applications.

Furthermore, micro molding must remain imaginative and innovative to overcome the new market challenges where parts and components become smaller and smaller. New technologists are doing just that!