3D printing technology is getting more and more mature, not only plastic
parts but also metal parts can be made.
Can 3D printing replace injection molding? The short answer is "no".
Firstly, the accuracy of each layer is a problem, and the printed parts,
either plastic parts or metal parts, their surface need to be polished, and
the manual polishing itself will increase the deviation of dimensional
accuracy. Because the working principle of 3D printing is to accumulate materials layer by layer or sintering and curing layer by layer.
Secondly, the selection of the material is quite limited. In the past, the
materials used in 3D were relatively photosensitive resins, With the
progress of 3D printing technology, now there are more choices, such as
ABS, nylon, POM, aluminum alloy, stainless steel, etc., but compared with
injection molding, there are still big limitations in the optional
materials.
Thirdly, making several pieces is ok, but for more quantity, the
cost of 3D printing will be expensive. In most cases, the 3D printing
technology is mainly used in prototyping and is not suitable for volume
production.
Lastly, material properties and strength problems
Although a few metal powders used in 3D printing can approach the material
properties of traditional metal materials, the 3D printing materials can
not meet the properties requirements of the standard material used in
injection molding, While the process condition is also a big difference
between 3D printing and injection molding, the Injection molding parts
forming process involves Melting solid plastic pallets into molten liquid
status by high temperature- Injecting the molten plastic fluid into the
mold by large pressure-Cooling and Solidifying Forming-Cooling, and the
forming melt temperature is mostly more than 200 degrees. 3D printing is an additive manufacturing process that builds parts and prototypes layer by
layer in the printer, with no need for such high-temperature conditions.
