Micro tooling is a process that involves tools whose diameter is smaller than 0.015″ and tolerance is no more than a few-tenths. Typically, micro tooling is streamlined when the manufacturing of complex and very fine parts is required. To achieve high precision and complex design requirements, the diameter of micro tools might be as small as 0.001″.
Micro tooling is usually associated with micromachining. Primarily, micro tooling is used in serial productions in CNC centers and in all industries that include micro components. The sectors that include micro tooling are the aerospace industry, automobile industry, die and mold construction for the manufacturing of exceptional parts, and dental & medical industry. Moreover, prototype construction for small but complex geometries also involves micro tooling.
One significant application of micro tooling is micro injection molding. The basic concept of micro injection molding is entirely like the idea of regular injection molding. The micro-injection unit is integrated with an ordinary injection molding machine. However, micro-injection molding is a molding process that supports the manufacturing of plastic components whose weight range between 1g and 0.1g. Besides, the tolerance of the parts made by micro-injection molding falls between 10 to 100 microns.
The micro-molding activates in a tooling department where a micro mold is made with a cavity looking like the part anticipated. The material is quickly infused into the cavity, forming the component at high speed. Generally, micro injection molding is used when small-sized and very précised components are needed.
Overmolding cannot be left behind when talking about injection molding. The seamless process that combines multiple materials to form a single part is referred to as overmolding, and the concept of micro tooling can also be applied here. Similarly, medical injection molding is a specified micro injection molding application that manufactures medical equipment like syringes.
Micro tooling has diversified applications in various fields. Here are detailed steps that clearly explain the process of micro tooling:
The micro tooling process is specialized for high-profile applications, and the same is the case with their manufacturing. The first step belongs to designing the tool, triggered by the purpose for which it will get used. For example, their diameter ranges from 0.025″ to 0.001″ and is decided considering the demand.
Once the design of these micro tools is ready, the next step is building or manufacturing. High-speed machining processes are performed with the help of CNC machines to manufacture these tools and ensure their accuracy and precision.
Having manufactured the required micro tool, now it is time to inspect them. The tool inspection involves if it can match high-speeds of spindles or not. Their feed rates are defined to avoid troublesomeness when they are being used. Given that, the microscope is the only way to figure out if the tool is safe or not.
Cutting tiny parts using an end-mill smaller than a human hair rank is a susceptible task. However, the maintenance of such tools is even more sensitive. Thus, micro tools require excellent care when it comes to their protection and upkeep.
The inspection is possible with the help of a microscope only, and if there is any issue, repairing is also performed under a microscope to avoid any loophole left untouched.
Accordingly, these are five steps involved in the manufacturing of micro tools. Meanwhile, there is no limit for diameters for macro tools, which are made to serve moderate difficulty level jobs. Their inspection, maintenance, and repair are much more straightforward than micro tools.
Both micro and macro tooling are overwhelmingly used in diversified industries. However, micro tooling is preferred to be streamlined only for high-profile applications like in the satellite and aerospace industry. Due to the highly specialized use of micro tooling, the costs incurred are higher than that of macro tooling. The reason is the high precision and accuracy of the micro tooling, which is impossible to obtain from macro tools. The cost for even a minor micro tool starts from tens of dollars and might reach hundreds of dollars.
In contrast, macro tooling also has specialized applications, but the cost involved is genuinely lower than that of the expenses of micro tooling. Carbide tools are the most common example of macro tools used for high-speed machining. The second factor that reduces the costs for macro tools is that the repairing, maintenance, and inspection for the macro tools is not much specialized compared to micro tooling. Apart from this, if a macro tool breaks, it would not cost as much as micro tools do.
Consequently, both tools collectively have a significant impact on the cost of injection molding.
With the mainstreaming of advanced technologies, the use of micro tooling is becoming more and more specialized. Micro tools offer their explicit services from the manufacturing of die and mold for micro-components to manufacturing other micro parts. Statistically, the global market size for micro tooling or micromachining was $2.5 billion in 2019, which reached $2.7 billion by the end of 2020 with a CAGR of 7.3%. Due to the more advanced and specialized use of tools, the global market size is expected to explode in the coming few years.