Design for manufacturing highlights the advantages of additive manufacturingNovember 25, 2019
Design for manufacture (DFM) is being cognizant of both device performance and how it will be manufactured. Additive manufacturing (AM) opens up additional production options, with DFM strategies being almost limitless.
Different types of AM have inherent characteristics such as material, strength and design constraints, where each lends itself to different uses and considerations.
While many may think of AM as a direct method of making parts, other hybrid methods exist that may be more suitable to industrial applications.
Binder jetting is a method where an adhesive is jetted onto a powder substrate, causing the powder to bond. This method makes a mold for casting. Instead of printing the part directly, sand is printed with a void in the shape of the part to be cast. When multiple copies are needed, binder jetting can also create a part that is pressed into sand to form multiple molds. Binder jetting can also create parts directly, but they are often weak. With the right materials, parts are strengthened by putting them into an oven to fully bond. Another use of jetting is the ability to make tools for other processes, such as sheet metal press dies.
Direct part printing for metals and polymers
Different types of printers exist for metal, but selective laser sintering or selective laser melting techniques are the most common. These printers sinter or melt powders to create a part. Fused deposition modeling uses a filament that is fed through a hot nozzle, which adheres to itself layer-by-layer. Stereolithography uses optics and optically cured resin to create a finished part. Parts made by these processes are generally used as the finished part, but can also be utilized in secondary processes or as tools.
Printing of metal molds for injection casting
Injection casting is one of the more common ways to make plastic parts, but molds take time and are often expensive. When casting plastic, time is needed for each plastic part to cool, which limits a line’s throughput. Actively cooling the molds speeds up the casting process. Using AM and DFM improves the internal design dies with better cooling for faster production. In one example, this sped up the cooling time by six seconds.
Design and manufacturing go hand-in-hand
The entire supply chain benefits from eliminating inefficiencies. Inefficiencies are often due to a failure to look at performance and manufacturing methods up front. This could apply to manufacturing on the OEM side, or to specialists or analysts who all have common tools upfront to create great products that are efficient, lightweight and perform better than before.
New manufacturing requires new designs
The design aspect cannot be completed without planning for manufacturing – they go hand in hand. Taking an existing part done in traditional manufacturing and trying to replicate it with AM is a poor approach. Instead, it is best to look at the part and figure out how to improve and optimize it.
The goal should be to remove as much weight and material as possible while considering the needs of the downstream process. The result is a part that is lighter, stronger and that will likely look completely different from the original but is just as functional. This is the idea behind utilizing DFM, finite element analysis (FEA) and AM. Instead of replicating parts that exist, replicate the function with new designs that outperform the original.
Making designs easier to manufacture
AM opens up design freedoms that were not possible before. Methods that enable new designs are the generative and bionic process. Generative designs work by providing goals in the software, which creates many design evolutions. This method returns many permutations and may turn up variations that the designer did not initially consider. Bionic design also uses nature as the inspiration and follows biology-based algorithms to create structural designs.