3D Printing Speeds Up Vacuum Metallizing

Plastic-Metals Technologies uses 3D printing to bring efficiency to a unique metallizing technique.

Industrial-grade 3D printing has long proven itself as a prototyping technology and, more recently, demonstrated itself as a process for manufacturing end products. A more subtle use of 3D printing has increasingly taken hold within industry, however, which sees it moving to additive manufacturing (AM) as a means of fabricating custom jigs, fixtures (end-use tools) and additional components that aid in other manufacturing or service applications. In this regard, AM may be particularly useful for very specialized services and production techniques.

Plastic-Metals Technologies, Inc’s (PMT) shielding solutions are just such a specialized service—the fabrication of custom electromagnetic interference (EMI) and radio frequency interference (RFI) shields. This type of shielding is often necessary for electronics or electronic devices that would otherwise suffer from crosstalk or interference as a result of electromagnetic or radio signals from other components within the assembly or other devices used nearby.

Randy Raugust, president of PMT, developed his unique metallizing process as an alternative to the sometimes messy and heavy-handed electroplating technique, which sees parts submerged in a liquid and plated as a result of an electric current. This method makes it difficult to only metallize select portions of a component while also requiring potentially hazardous chemicals and electricity.

Vacuum metallizing, in contrast, sees parts enclosed in a vacuum chamber before metal particles are deposited onto select surface areas. The process is a fascinating one in which a metal such as nickel, copper, stainless steel or aluminum is attached to electric coils and heated to its boiling point. Once the metal becomes gaseous, the metal particles condense and float onto the parts, giving them a thin layer of metallic coating.

Currently, many of PMT’s customers are in the medical industry—manufacturers whose devices require a layer of copper and aluminum to prevent EMI and RFI. With a range of products that receive layers of shielding, PMT must mask the parts as they are attached to the metallizing rig so that the metal particles are not applied to areas that don’t require them. 

A medical device with a metallized interior to prevent EMI.

A medical device with a metallized interior to prevent EMI.

In some cases, simple squares of silicone are sufficient, but, with more sophisticated parts, PMT needs to have masks laser cut by a third party, a cost that has totaled roughly $30,000 so far this year. For one customer, Raugust pointed out that he shields about 90 parts at a time on a single rig. With a customer for whom he shields 1,000 parts a day, he needs to have six rigs, adding up to about 540 individual masks. For this reason, PMT has decided to 3D print custom masks in house.

In PMT’s search to find the right 3D printing platform, the dominant brand of fused filament fabrication printer (FFF) was too expensive to bring in house. Raugust, however, discovered a new generation of FFF 3D printers beginning to emerge that offered the quality expected from professional systems, but without the costs associated with the machines and materials. His choice was manufactured by 3ntr in Italy and brought to the United States by Plural Additive Manufacturing (AM) in Lake Oswego, Oreg.

A specialty 3D-printed part, with pre-metallization on the left and post-metallization on the right.

A specialty 3D-printed part, with pre-metallization on the left and post-metallization on the right.

To fabricate such a large number of custom masks, PMT purchased a 3ntr A2 3D printer. The 3ntr systems are capable of 3D printing a wide range of materials, but ABS was more than adequate for use with Raugust’s process and the A2 3D printer, which has a massive build volume of 24 in x 13.7 in x 19.7 in and is sizeable enough to print large batches of masks. PMT found the cost per part, quality of the parts, and overall price to be extremely attractive. Factoring in the annual costs of the printer, maintenance, and all the materials, PMT estimated the cost of 3D printing with the A2 to be 50 percent less than turning to a third-party laser cutting service and much less than many 3D printing service bureaus.

Enter the 3ntr 3D Printers

Plural AM Cofounders Tom McKasson and Ed Israel relayed in an interview with ENGINEERING.com the critical importance of fabricating parts within specific manufacturing tolerances. A key differentiator between an industrial-grade machine like those from 3ntr and the cheaper hobbyist machines is the high degree of accuracy and repeatability when 3D printing parts.

The A2 and A4 3D printers from 3ntr at Plural AM headquarters.

The A2 and A4 3D printers from 3ntr at Plural AM headquarters.

The design of the 3ntr systems can be attributed to Davide Ardizzoia, who worked tirelessly on developing the machines in Italy. The systems have been engineered with repeatability and accuracy in mind, including three water-cooled, all-metal hot end extruders and a sealed print chamber. This allows for precise control over the printhead temperature, which can reach up to 410 oC, making it possible to print such materials as polycarbonate (PC), high-impact polystyrene, nylon, polyethylene terephthalate (PETG), thermoplastic polyurethane (TPU), IGLIDE (a self-lubricating plastic), PC-ABS, acrylic-styrene-acrylonitrile (ASA), and nylon-carbon composites, as well as traditional ABS.

The A4 3D printing parts for a customer.

The A4 3D printing parts for a customer.

In addition to Ardizzoia’s designs, Plural AM has contributed a lot to the machines when bringing them to North American users. For instance, the firm works closely with Jonathan Dummer, chief programmer of KISSlicer, which the Plural AM team says is an extremely efficient and precise slicing software due to Dummer’s background as a mechanical engineer and mathematician. This relationship enables the regular enhancement of the slicer, extending significant print capabilities based on customer requests.

Display parts 3D printed by Plural AM with 3ntr machines.

Display parts 3D printed by Plural AM with 3ntr machines.

Plural AM also includes standard add-ons to its printer packages that may be essential for integrating the A2 and A4 systems into a modern office or factory, such as a HEPA filtration system eliminating fumes from printing, Wi-Fi capabilities for cloud control and print management, a webcam for remote monitoring, a one-year warranty and Plural AM’s expert support.

Some of these features, specifically filtration and remote monitoring, still have not been incorporated into the printers of more expensive brands. Other features, such as Wi-Fi capabilities, are only now being integrated into other systems. In this way, Plural AM, the exclusive representatives of 3ntr in North America, seems to understand what is needed if 3D printing is going to be transformed from a prototyping tool to an actual AM technology.

Plural AM has sponsored ENGINEERING.com to write this article. It has provided no editorial input. All opinions are mine. —Michael Molitch-Hou.