The short answer Injection molding is a repeating process that melts thermoplastic pellets in a heated barrel, injects the melt into a closed steel mould under 60 to 150 MPa, holds it under pressure while it shrinks, then cools and ejects the finished part. One cycle takes 15 to 120 seconds, cooling is 50 to 80 percent of that time, and the cycle then repeats automatically. A machine is three ...

The short answer Injection molding fills a machined steel cavity with molten resin under 60 to 150 MPa, so it holds plus or minus 0.025 to 0.05 mm, delivers Class A surfaces and keeps 95 to 100 percent of the resin's rated strength. 3D printing builds the part layer by layer with no tooling, holding plus or minus 0.1 to 0.5 mm and retaining 60 to 85 percent of rated strength. The physical diff...

The short answer The main advantage is unit cost at volume. Injection molding needs a mold costing USD 2,000 to 40,000 and takes 2 to 8 weeks to build, but then a part costs USD 0.10 to 2.00 and leaves the machine every 15 to 60 seconds. Additive manufacturing has no tooling but a part price of USD 1 to 40. One number carries the whole argument Every other difference between the two processes ...