Can I use additive manufacturing to mass produce custom plastic parts?

The answer is, it depends on what you mean by production parts. If you are making 15 sets of parts for a pilot - then absolutely, 3d printing, or SLA, or any of the other rapid prototyping processes would be appropriate. We would argue that that is not production - that is a typical prototyping run, and rapid prototyping processes are very appropriate.

If, instead, you are making 50,000 parts, then you really need to look into injection molding. This is because you cannot wait 24 hours for each part to finish printing. You probably also cannot accept the fit/finish and material properties of a plastic part made with any of the common 3d printing techniques in 2020 - especially for consumer electronics applications. In that event, you might be looking into a process that can make thousands of parts per 8 hour shift in the contract manufacturer's facility. 5000 parts a day over an 8 hour shift means the process needs to produce 10+ parts per second. That is not a financially viable proposition even with a farm of 3d printers.

The best way to understand the difference between prototyping and mass production is to look at what Stratasys, a leading provider of on-demand parts, offers. As of 2020, they offer both rapid prototyping processes for design validation and for making one-off fixtures, as well as short-run options with mass production style processes such as injection molding.

Now this is a rapidly evolving field. We are excited to see what the next decade will bring in terms of new manufacturing techniques that can make additive manufacturing fast and cost effective.