CNC machining and injection molding are common methods of manufacturing parts. Both processes are used to manufacture different types of parts and components. But each of them is different from the other and here we will tell you how.
The process of CNC usually starts with the material you want to use. CNC machining removes material layers, one at a time precisely, and you can use multiple materials with few limitations. And it can deliver extremely precise tolerance since it is computer controlled.
Injection modeling, as per its name, is a process where you inject the material into a mold by melting it and forcing it into the mold at high pressure. After it cools down, it is ejected from the mold and is repeated for the next part.
CNC machining is the fastest and if you want too much in too little time, this is your only way out. It takes time for injection modeling to make the mold along with making sure that the parts are in the line of tolerance. This is what takes time but once this part is over, creating the parts with molds is quite faster.
If you need a few hundred parts, CNC is the cheaper option. While it offers you some advantage of volume in the price, it is usually considered advantageous between a few and a hundred parts. Anything more than that and you won’t get any additional benefit. When it comes to the real cost for every part of injection molded parts, it is considerably cheaper as compared to machined parts. However, creating a mold can be very expensive for injection molding. But the more you create, the cheaper it gets.
You can use a variety of effective materials to create the parts with CNC machining. So, if you need to work with a specific plastic or a high-performance material, this is the process you must opt for. But when it comes to injection molding, the selection of materials can be quite stringent. However, companies are coming up with more and more high performing materials for injection molding.
With CNC machining, you can get a tighter tolerance and a better surface finish, but with injection molding, you can get the repeatability in every lot. You can make a million identical parts with one mold with minimal wear.
It is hard to change the design of a mold, so, if the design of the parts you are making has any chance of changing, you might not want to go with injection molding. It is impossible to modify the mold for any changes in design. On the other hand, CNC machining allows for more flexibility. You can make multiple features with machining as compared to injection modeling.
This is how CNC machining is different from injection molding. So, carefully consider each element before picking up what process you want for the parts you are manufacturing. A wrong decision can leave you with a lot of unwanted expenses.
This content is brought to you by Orton Watt.