Wider industrial adoption of additive manufacturing likely is revolutionizing manufacturing: as of 2Q 2019, around 51% of enterprises have used 3D printing for part production. Obviously, many of businesses believe 3D printing boosts performance and simplifies fabrication of parts, and optimizes supply chains.
But, the other 49% apparently are yet to be persuaded, and the various AM/3D printing processes still have drawbacks that are critical to acknowledge. Some of those problems involve the production processes, while others concern their effects on the enterprise.
Here are a few reasons that 3D printing might not be the right production process for your enterprise.
1. Machines and materials are expensive — As an emerging technology, additive manufacturing systems can be expensive, with some machines costing hundreds of thousands of dollars. Selective laser sintering (SLS) and laser melting (SLM) machines, for example, are extremely capital-intensive. The high price is easier to understand if you consider the process of additive manufacturing and what it requires.
In contrast to subtractive manufacturing in which excess material is cut or carved away from a workpiece, 3D printing adds material layer by layer to form the workpiece. Although 3D printing can produce parts with many materials, including various metal powders, ceramics, thermoplastics, composites and glass, some printers are compatible only with proprietary materials, which add to the cost and may limit design variables, like color and texture.
Even if your AM process can use the same materials as the analogous subtractive manufacturing operation, you cannot make a simple 1:1 part comparison. For example, if you’re manufacturing molds or dies, you’re unlikely to see any degree of success producing such parts by additive manufacturing.
It’s important to remember that 3D printing works well in certain niches, but not all. Because 3DP still an expensive and time-consuming process in regard to cost-per-finished part, you will have to determine whether the value added value by the production process justifies the high capital and/or operating cost.
2. 3D printing requires specific conditions — A 3D printer requires specific conditions for proper usage. For example, printer bed must be aligned properly, so that as the object is built, each layer matches the preceding one, and no defects are built into the part. However, printers can fall out of alignment over time as operation may cause the bed to move.
As a machine comes out of alignment, the operators have to stop production to "re-level" the 3D printer. This may lead to downtime on production projects. Operators must periodically check the alignment and recalibrate the 3D printer to ensure this does not happen, which can be another unnecessary expense for related manufacturing processes.
Although it's possible to design virtually anything on a 3D digital canvas, it's impossible to print everything. The machine must produce each layer over an underlying material, since it can't print on thin air. If you don't follow this guideline, and the layers of your part don't receive support from the underlying layers, you'll produce an “overhang” and create a weak object.
Each 3D printer has a different maximum angle it can produce without the need for support material, so it’s important to decide which angles you'll need to produce for your parts.
3. Managing the software can get confusing — What makes 3D printing unique is the software involved in the design process. After you have defined the object through computer-aided-design (CAD) software, the data is converted into a .stl file that slices the object into super-thin layers, and that information becomes the basis for the 3D printer’s production program — comparable to a toolpath program for a CNC machine. The data guides the print head or nozzle to deposit the material layer by layer.
While the software allows for highly customizable designs, it's often difficult to master. Makerbot, one of the leading 3D printer manufacturer companies, boasts over a million downloadable files that customers can use within the CAD software, but still acknowledges that users must educate themselves fully on the process and technology for using them.
4. It’s a time-consuming process — Many 3D printing processes are very time-consuming that do not make sense for high-volume parts production, nor the enterprise schedule. Depending on the technique and the complexity of the design, creating parts and objects by additive manufacturing can take from 6 minutes to over 11 hours per item.
The time necessary to produce a part depends upon the 3D printer, rather than the operator. To operate the machines, you must load the 3D files, allow the machine to preheat, and build each layer. But, you must also allow time for quality control during production.
If you are considering switching to 3D printing process, it’s imperative to consider the number of parts you need to form and whether it will be time-efficient to 3D-print them. Consider too that many parts may require post-processing to smooth the rough edges or excess material after printing.
5. Parts can warp or distort after production — Even after cleaning up your 3D-printed workpieces’ rough edges, it is possible that residual stress and shrinkage may induce warpage or distortion. For 3DP metal parts, internal stress may lead to warping of the build plate, resulting in fusion problems.
Another issue is layer delamination caused by rapid cooling, residual stress, and incomplete melting. Unlike cosmetic surface defects, these macroscopic defects are impossible to fix through post-processing. Considering the time it takes to produce the part, along with the time needed for post-production, additive manufacturing may not be the most efficient solution for your production needs.
Is 3D Printing Right for You?
While 3D printing continues to develop and change to fit the manufacturers’ needs, there are still some key issues that can hinder your production process. You'll have to consider the previous points as you determine the value of additive manufacturing for your business.
After thinking about the types of parts and systems you are trying to create, the number of objects you want to produce, the time constraints of your company, the costs of the AM machines and upkeep and the possibility of part distortion after production, you can then decide if 3D printing is the best production technique for your business.
Kayla Matthews writes about the IoT, IIoT, automation and smart technologies for publications like InformationWeek, Manufacturing.net, Robotiq others. To read more from Kayla, follow her personal tech blog, Productivity Bytes.