We have been watching the 3D printing revolution for a long time. As a plastic injection mold and molding provider, we recognize the opportunity 3D printing offers. We also recognize that things are not as simple as they appear. We have had a number of customers inquire about it, and helped to facilitate experimenting with 3D printing to obtain their prototypes.
Problem is we make serious components in serious engineered thermoplastics. We see articles written about the marvel of 3D printing/additive manufacturing, and it seems when the printed component is described, there is usually a “but” attached. It is rough looking, it is not the final color, it is 70% of the actual strength, etc. The time saved in making design iterations is touted, but the actual total cost of the 3D part, including equipment cost, material, overhead, training, and support, we never see mentioned.
PlastiCert is still of the opinion that 3D printing is not yet the panacea that is being thrown about.
- The CAD designs are sometimes not a simple plug-n-play. Many CAD outputs requiring file manipulation to facilitate getting the printed part that you were actually seeking. Many times parts look fine in 3D on screen, but feature junctions cannot mate correctly, walls can be too thin, geometries can result in voided material areas, etc.
- You can design a part to run on 3D printing, but that does not mean you can injection mold that same part. To make some of the complex features that 3D printing is famous for, the mold would be either exorbitantly expensive, or impossible. For low volumes, the answer may be to do production on the 3D printer. For mid to high volume, it would mean back to the drawing board. If you are designing for injection molding but focused on using 3D printing, it can cloud your vision.
- The composites we use in injection molding are not available or yet possible to use in a 3D printer. There are initial reports of a new development by Arburg (the injection molding equipment company), but for now 3D printers require their special 3D printing versions of thermoplastics. While they are close representations of the thermoplastics you use for injection molding, they are not the same and they are quite expensive.
- The 3D parts are made of numerous layers upon layers. As such, the parts are not as strong as the injection molded version of the part. In addition, if you plan to use a glass filled composite for production, you cannot 3D print it as stated above. You will have a physically different part. You will not be able to do any definitive functional testing of the 3D part; only form, fit, and limited function.
- Lastly, 3D printing is now being used to make prototype molds, i.e. you need prototype parts out of the production composite resin that cannot be 3D printed. For less demanding parts/resins, this is an option. Naturally, the mold material must always be more robust than the part material or you end up with a giant block of melted mold and part together. Most of the parts we injection mold are high-end composites that melt at 400 to almost 700o F, too stressful for 3D resins.
3D printing is here to stay, but as with all manufacturing methodologies, it has its advantages AND disadvantages. Becoming part of the design evolution and allowing an engineer to double check his work does add value. The question is how much and is it worth the cost? Each OEM company will have to make that determination. In manufacturing, we have the mantras of doing it right the first time and eliminating steps to improve efficiency and cost. Should that be the same consideration in design as well? If you run off to the 3D printer with each design iteration anxious to see how the parts fit together, what are the odds you end up adding more time to the schedule than you intended to save? Moreover, you are still going to have to mold the final designed part(s) and then do your physical testing. Granted, the higher the mechanical complexity, the more potential exists for 3D printing to add value to your design process. Therefore, while 3D printing can help save a company some cost, it can also result in added time and expense if not managed correctly.
The salesperson in us says tell the customer what they want to hear. The business partner for our customer in us says be straight with the customer and tell them what we think. When 3D printing has a more direct correlation to injection molding, we will get even more excited about it. For now, we will work hard to help our customers get their designs and molds right the first time, and will leave making toy samples to the UPS and Staples stores.