what IS AM AND WHY IS IT APPEALING?
It does what it says on the tin: AM is the process of making a 3D object of virtually any shape from a digital model, through an additive process where layers of material are laid down. This differs from more conventional subtractive manufacturing methods like machining a larger block of material down into the required shape. 3D printing makes use of certain materials, like plastics and resin, and different methods to lay them down, like PolyJet printing, which drops liquid photopolymer and uses UV light to solidify them, or Selective Laser Sintering (SLS), in which a laser essentially melts the printing material, which then fuses to form the designed part.
Though the list of materials and printing methods can be overwhelming to grasp at once, it still helps to get familiar with them, in order to discern what material or method might be suited to what you want to produce. For example, PolyJet and Stereolithography (SLA), another printing method similar to PolyJet printing, can produce products with smooth surface finishes, and are usually used for rapid prototyping. SLS, on the other hand, lacks the need for support structures during the printing process, and thus can also be used for more complex parts along with prototyping.
AM can be appealing to some manufacturers because of its flexibility and usefulness in producing high-cost lowvolume parts, as on-demand manufacturing that AM provides allows for that. For example, Align Technology, the creator of Invisalign dental aligners, has partnered with 3D Systems, a company that deals with 3D printing products and
services, to produce 320,000 custom aligners a day.
Another reason is that, if used right, it can shorten time-to-market, as you could quickly prototype and test a product by submitting a CAD file to a printer and altering the design afterwards. This also allows you to be more marketresponsive as well, as changes in response to feedback can be made, fast. In that sense, design can be thought of as having an outsized role in AM.
Of course, there’s also the cost factor, though this is more complicated. The most obvious one is materials, but there’s also stock management costs and operational costs, like maintenance and labour. The cost of keeping your machine up and running is one to consider, but so is the lack of tooling costs compared to subtractive manufacturing, for example. Acquiring design expertise is also important as well. Overall, if you’re looking to adopt AM, other costs might come from obtaining design expertise and accounting for early mistakes.
If you have any form of manufacturing in your supply chain, like producing a lowvolume product to be sold or supplying a product to other companies, adopting AM can help streamline the manufacturing process by consolidating multiple parts into a simpler assembly line (like making the whole product rather than sub-parts to be assembled), potentially reducing lead times and costs while increasing market responsiveness. Or, if you’re just simply looking for a way to get a quick cosmetic prototype, AM can help achieve that.
That’s not to say that the AM workflow isn’t obstacle-free. If you’re early in the AM adoption process and the lack of design expertise can mean an un-optimised workflow and parts that come out flawed; the ability to quickly edit the design in CAD software helps, but mistakes will still increase lead time. There’s also the issue of material sensitivity; for example, metal 3D printing needs a carefully controlled environment involving inert gases to meet design standards. These are just some examples to consider when beginning the process of adopting AM.
It should also be important to note what parts of the manufacturing process are suited to AM, and what parts are suited to more traditional methods. AM is restricted to the size of the printing area, for example. But at the same time, AM may be more suited to prototyping than something like CNC machining, as 3D printing doesn’t require a skilled operator outside of someone who can prepare a CAD file. The best way to look at it then might be to think of subtractive and additive manufacturing as complementary. One such example is 3D printing a mould for injection moulding.