by Melissa Donovan
Three-dimensional (3D) printing is used in appliance manufacturing. Prototyping various parts of a refrigerator, stove, or washing machine prior to mass production using 3D printing methods offers flexibility, cost effectiveness, and quicker time to market.
Beyond prototyping, custom parts for one-off or replacement items are common and additive manufacturing (AM) is a great way to produce them. Appliance manufacturers no longer have to hold a wide inventory of spare parts. If one is broken or goes missing, they can print a replacement at a location local to the customer, and send it out on demand.
Five of the seven ISO/ASTM 52900 standard categories of 3D printers—powder bed fusion, material extrusion, vat photo polymerization, binder jetting, and material jetting—are used in appliance part production. The most prominent is fused deposition modeling (FDM), which is considered material extrusion and selective laser sintering (SLS), which is part of the powder bed fusion family. Both are mature technologies, hence the popularity.
That being said, other processes in 3D printing are also favored when it comes to manufacturing appliance parts as technology advances and more manufacturers realize that many other types of materials—or filaments—can be used for prototyping as well as spare parts.
Serving The Supply Chain
Appliance manufacturers benefit from 3D printing. While it is still a slower process compared to other manufacturing methods, it is useful for the creation of prototypes and spare parts.
3D printing is ideal for appliance manufacturers because it can provide quick, accurate prototypes. “AM gives the most flexible solution for appliance manufacturers to prototype and create parts. Advanced rapid prototyping technologies enable them to produce parts that can’t be done in established manufacturing methods, or speed up this process several times. It also makes it more cost effective,” explains Maxime Polesello, CEO, Sinterit.
“There are hundreds of small components manufactured via CNC machining, stamping, casting, and other traditional methods that could be consolidated into one component that is better performing and has improved durability and functionality,” notes Winthrop Sheldon, VP of sales and marketing, SLM Solutions Americas.
Quickly creating prototypes is important for manufacturing and the foundation of any design improvements, according to a representative from HP Personalization and Industrial Business. “Unlike traditional methods, 3D printing does not create product design constraints—such as design structure or shape—and allows users to print prototypes directly and quickly, which shortens the design period. It also allows manufacturers to take new concepts that can immediately be printed and tested in 3D, saving time when it comes to launching new products.”
“The ability to print functionally appropriate parts that improve both overall design and performance as well as identify potential downstream manufacturing issues has significant value. Creating functional prototypes facilitates an iterative process for part design before committing to high-cost tooling traditionally associated with the sector,” explains Colin Blain, application development engineer, 3D Systems, Inc.
Gregory Elfering, president, Ultimaker Americas, considers 3D printing as a complement to other manufacturing processes. “It is a useful complement to the portfolio of production technologies to stay productive and ahead of the game with innovative product design. 3D printing is ideal for appliance manufacturers since it offers more design freedom and quicker prototypes.”
Appliance manufacturers also rely on AM to quickly create spare parts. “Replacement parts for end customers are a huge challenge for any manufacturer. For any given system, there can be hundreds of spare parts that a manufacturer would need to produce, stock, and manage—which creates high inventory and carry costs,” shares Michael Mignatti, VP of engineering, MakerBot.
“3D printing these parts on demand can provide significant cost relief. The parts can be printed in hours and shipped to the customer. With advancements in materials, parts have moved beyond ABS to include functional parts for the end product,” continues Mignatti.
Reducing stock, minimizing cost, faster production, as well as less waste as a by product of the manufacturing process are additional reasons appliance manufacturers work with 3D printers, says Laura Longoni, sales manager, Sharebot srl.
Using 3D printing for spare parts provides an extra service for the appliance customer. “3D printing offers appliance manufacturers the opportunity to provide an extra service to their customer who can benefit from the technology by ordering specific spare and customized parts or accessories,” explains Elfering.
Having immediate access to a 3D printer is helpful in times of crisis. “All manufacturers experienced first hand in 2020 that a global pandemic does not only disrupt supply chains, but it also impacts what appliances customers want and need. 3D printing can help an appliance manufacturer create the parts needed to adapt their production line from building vacuum cleaners to respirators,” adds Elfering.
“It doesn’t matter if manufacturers need a quick prototype, individual objects, or want to start a series production, AM can serve every area. Compared to conventional production like injection molding, appliance manufacturers won’t have high setup costs or long lead times before they can start the production,” affirms Andrea Berneker, marketing manager, InnovatiQ GmbH + Co KG.
Despite how useful 3D printing can be in regards to the appliance industry, Mignatti cautions that users must be targeted in their utilization. “The cost and time to produce a 3D printed part still lags behind most mass production processes such as injection molding. It can be a great tool for last minute changes—printing parts while hard tooling is getting updated can allow the manufacturer to produce and continue to sell their products.”
Bits and Pieces
Appliance parts small and large are prime candidates for 3D printing. Blain says that appliance manufacturers rely on 3D printing to create everything from high precision components within complex functioning mechanisms to large format external case parts—and everything in between.
“Just think about the almost endless demand for industrial seals made of liquid silicone rubber and the miniaturization of electronic devices where seals are commonly used. With 3D printing, manufacturers can quickly adapt the market,” notes Berneker.
Some specific examples of parts that could be manufactured using 3D printers, according to Trent Allen, CEO, Tethon 3D, are small connectors, catalytic converters, heat sinks, and thermocouples. “This keeps inventory space down by being able to 3D print on demand or for lower batch productions.”
These types of customers of SLM Solutions focus on heat transfer devices with improved thermal performance. Sheldon says heat exchangers in particular are becoming a leading application to build with metal AM.
Based on Elfering’s experience, 3D printing is mainly used to create useful production equipment and tools, however more parts are created in small batches as well as customized pieces and other accessories.
For example, he points to high-end domestic appliances and commercial equipment manufacturer, Miele. “Besides using the technology to be more productive and efficient, it also helps design and redesign products.
Furthermore, Miele already allow customers to download files of certain accessories for their appliances for free so customers can print them locally,” shares Elfering.
One benefit of 3D printing in manufacturing is the ability to create geometries impossible to construct with traditional technologies. “In appliances, this provides great benefit in producing fluidic parts—such as manifolds, ducts, and valves—due to the difficulties of injection molding for those types of parts. Most often, you can replace the assembly of several different parts with a single 3D printed part, which makes digital manufacturing faster and more cost effective,” explains HP.
Technologies at Work
Popular processes used to manufacture appliance parts include material extrusion—FDM; powder bed fusion—SLS, selective laser melting (SLM), direct metal printing (DMP)/direct metal laser sintering; vat photopolymerization—stereolithography (SLA), digital light processing (DLP), and liquid AM (LAM); binder jetting—multi jet fusion (MJF); and material jetting—multi jet printing (MJP).
Part of the material extrusion category, FDM is popular for its ease of use, inexpensiveness, and a variety of material availability. Mignatti says that the polymer-based process is preferred for internal parts and part replacements.
“The investment in an FDM printer is manageable, a range of materials can be printed, the material properties and quality are close to injection molding material, and easy post-processing is possible. The cost-benefit ratio is therefore optimal,” adds Berneker.
Alex Riestenberg, AM product manager, Cincinnati Incorporated, agrees, saying FDM is preferred because of its ease of use and ability to create parts for a range of applications and uses.
Adding to the popularity of FDM, it’s an inexpensive entry into the market, admits Peter Durcan, VP, 3DCeram Sinto, Inc. He notes that it can be limited in regards to industrial applications.
FDM 3D printers work with a variety of materials, according to Mignatti, like acrylonitrile butadiene styrene (ABS) and polycarbonate—both solid candidates for appliance parts. Advanced materials—such as nylon carbon fiber—are also possible, which result in stiff, functional parts for a variety of challenging environments.
ABS is a common, standard material in FDM printing, notes Berneker, as it can be post-processed well and is inexpensive. Acrylonitrile styrene acrylate (ASA) is another filament used in FDM. Its processing and properties are comparable to those of ABS, but ASA stands out for its UV resistance.
“Polylactic acid or PLA and polyethylene terephthalate glycol (PETG) are popular materials since they are easy to print. PETG is a tough material and since it is slightly bendable it is more suitable for functional parts. It also has high chemical, temperature, and wear resistance, making it the preferred material for industrial environments,” shares Elfering.
Polycarbonate is another FDM filament. It features good mechanical properties like high impact strength and heat resistance. “The material is suitable for a wide temperature range,” says Berneker.
While FDM is popular for its ease of use, cost effectiveness, and vast material selection, a second popular 3D printing process used in appliance part production is SLS, shares Durcan.
According to Polesello, SLS is at the beginning of its development. “The potential of this technology is amazing and therefore we forecast further dynamic growth. SLS provides a wider material range, better material properties, and the freedom of design. This technology doesn’t need any supporting structures, and it is possible to print movable elements.”
SLS, a powder bed fusion technology, is preferred because it offers good surface finishing. It isn’t the only type of 3D printing to offer this. SLA and DLP—vat photopolymerization processes—also do so.
“SLS, SLA, and DLP are more appropriate for larger components where higher precision with a higher degree of surface finish and properties such as optical clarity are requirements,” explains Blain.
SLA is a polymer-based 3D printing method, which Mignatti says can produce high cosmetic and accurate parts due to the feature resolution achievable on these machines.
DLP is favored thanks to the durability reflected in the material used. “It is ideal for complex, high-fidelity components in a range of materials that can now be realistically used for long-term functional prototyping as well as creating opportunities for production parts. This is largely due to the long-term stability and long-term mechanical properties of the materials, which better satisfy the requirements of the end use part,” explains Blain.
Berneker points to LAM as a vat photopolymerization process gaining relevance in the manufacturing of appliance parts. “It is not only possible to 3D print liquid silicone rubber but also other liquid materials like polyurethane. Other materials can also be processed in this way, for example epoxy resins, adhesives, waxes, or ink.”
Sheldon believes SLM, a powder bed fusion technology, is gaining ground on polymer-based technologies like FDM and SLA. This is particularly true for metal AM, with aluminum and steel materials gaining in popularity.
“Powder bed fusion with metals enables printing of final dimensioned metal parts without the need for subsequent de-binding and sintering. In most instances, acceptable parts are printed in the first iteration,” shares
Dave Jankowski, commercial operations leader, Xact Metal, Inc.
Jankowski notes that while metal powder bed fusion is not a high-quality or high-volume process, it is best used for prototyping; tools used in stamping, machining, and robotic handling; and printing of small-quality customized parts.
DMP, another powder bed fusion method, is ideal for parts with metallic components—either prototypes or end user components—when the economics are appropriate, according to Blain.
“MJF is a best fit for industries looking to speed up product development and time to market, create final parts with best-in-class isotropy and mechanical properties, as well as the scalability and unique productivity opportunities that the technology brings,” notes an HP representative.
MJP is also used for functional prototyping, “as there are great materials for high-temperature applications, optical clarity, as well as the capability to print sacrificial wax patterns that will be used to produce metal components,” adds Blain.
In the long term, Elfering sees more companies offering design files of spare parts for customers to print on their own, similar to the aforementioned Miele example. “By storing these high-quality files in a digital library, it becomes easier to print them locally at the moment when it’s needed, achieving a just-in-time inventory system.”
“We are seeing a move away from prototypes and into more end user production parts. As AM becomes a more trusted, mainstream form of making parts, we believe more end user parts will be made using AM. Additionally, jigs, fixtures, and other manufacturing aids will continue to be popular in AM,” agrees Riestenberg.
3D printing’s usage in creating appliance parts “will continue to change and advance in the future with the ever growing industry of 3D printing. We are getting closer to production quality right off of 3D printers, which will cut time and material costs,” notes Allen.
“I believe 3D printing will continue to advance in the future as the materials and material delivery systems advance. Economics will always be a factor—especially when compared to current processes like injection molding. However, the ability to customize and have virtual inventory, as well as print on demand, will help drive the adoption of AM as an end use manufacturing process for this category of product,” concludes Blain.
3D printing’s move into appliance manufacturing is slow but steady. More manufacturers of vacuums, washing machines, and air conditioners will begin to understand the benefits of utilizing on-demand printing in house—whether for prototyping or spare/replacement parts. As technology advances, eventually these production facilities will utilize 3D printing in some way in their actual production lines.
If you are interested in learning more about 3D printing in appliance manufacturing, be sure to visit our website and register to view the archived broadcast of our webinar on this topic.
Throughout the month of April, check back on industrialprintmagazine.com to read up on actual appliance manufacturers utilizing 3D printing in house. Some of their experiences are depicted in images throughout this article. IPM
Apr2021, Industrial Print Magazine