Metal, or Plastic, and the 4th Industrial Revolution

After about 30 years of 3D printing and after adopting Additive Manufacturing as the more correct name for this wide offering of different technologies, allowing for the creation of objects from scratch, with no any intermediate tooling and directly from digital data, the common holy grail is, moving additive manufacturing into real, mainstream manufacturing.

While being dominated for over two decades by small companies that became big, in the last decade the real industrial giants understood the potential of additive manufacturing for manufacturing and entered the space, some through M&As and some through organic R&D. These giants are stating, very clearly, that manufacturing is their only interest in additive manufacturing, and there is no need to explain why.

Another recent decade additive manufacturing phenomenon is the emerging of new companies, that became additive manufacturing unicorns by also, aiming at providing industrial additive manufacturing solutions to enable the fourth industrial revolution to happen.

There are many challenges that additive manufacturing must overcome to allow penetration into the manufacturing space; materials, productivity, meeting and adapting regulations, integration in the manufacturing management workflow, etc. Here I will focus on the materials’ barrier.

Another characteristic of the recent decade in additive manufacturing is the “metal fever”. It is true that using the “real” materials in additive manufacturing is one of the important factors to open the road to manufacturing, but is metal really the only answer, from the materials’ aspect, for this need?

I am not underrating the need for metal to meet the industrial needs to adopt additive manufacturing as a mainstream manufacturing method for the present and the future. My claim is twofold: 1. There are many products that are now made of metal, even though, an advanced polymer-based additive manufacturing solution could add significant functional and additional advantages to those products, 2. Trying to make metal additive manufacturing a usable industrial solution is great, but kind of being “counter-revolutionary”.

Plastic started its industrial phase at the beginning of the 20th century. In 1907, Bakelite, the first completely synthetic plastic was invented by Leo Baekeland. Following the invention, various chemical companies invested in research for invention of new plastic polymers. World War II further created a surge in plastic production thereby expanding the plastic manufacturing industries throughout the globe.

Around the 1950s, plastics began to replace metals in various manufacturing industries. The invention of new plastic resins changed the scenarios, bringing to light the clear advantages of using plastics over metals.

Various factors like durability, flexibility, reliability, cost efficiency, faster production rates, etc., made plastics a preferred material for creating industrial parts.

Plastics are made from different resins. While each plastic resin has its own properties, all polymers in general offer superior flexibility when compared to metals. For industries that need more options in terms of designs, textures, and geometry, plastics are a better choice. And weight – there is no comparison with metal when weight is of the essence, and its is getting more and more important.

My 1969 VW Karmann Ghia’s body was all metal. In today's cars, many parts, even the bumpers are made of polymers. Under the hood of the Karmann Ghia, there were only a few plastic parts, while today, when you want to jump-start a car, you need to look for metal. No doubt about it, when plastic can do the work, manufacturers will always prefer it over metal.

But not in additive manufacturing. In additive manufacturing, we have inherent limitations that do not allow us to meet the real industrial needs when polymers are concerned. We see “real” polymer materials in use (such as Ultem, Peek, Nylon, etc.), but additively manufacturing them to the required industrial standards is still complicated and prohibitively expensive, thus limiting their use to unique applications. When elastomers are needed, we only have “like” materials and not the real thing.

There is a huge space of applications that are still manufactured in the traditional methods because there is no good enough additive manufacturing method to make them. On the other hand, there are many metal parts that could benefit being made of polymers, if only there was a viable additive manufacturing method to make them.

I have recently been exposed to two concepts that could address the matter I elaborated on here.

One concept is to metal plate additively manufactured parts. In this way manufacturing is significantly cheaper than of metal, 50-70% of the weight is saved, advantages of additive manufacturing advantages are gained (complex geometries, less assembly needed, short lead time, customization, etc.), while advantages of metal are achieved to an extent: part strength, thermal and electric conductivity and heat durability. This is not a complete metal substitution method, but has its own advantages and can address many cases where metal could be replaced.

The other concept is an innovative additive manufacturing method that overcomes many of the constraints of current technologies. This technology will print different materials with no material viscosity and particle size limitations. This will allow to print the “real” and not the “like” polymers. This innovative technology also allows for “on the fly” creation of new different multi-material structures, that will enhance properties impossible to achieve with traditional, non-additive polymer manufacturing methods.

Between plastics and metal, there is also an additional immense opportunity for additive manufacturing in composite materials. There are beginnings, such as a technology developed by Markforged, but that is only an initial step.

My bottom line is, therefore, that there is a 200% justification to pursue the holy grail of real industrial metal additive manufacturing, but when manufacturing is concerned, then industries have no less need for advanced polymers additive manufacturing in their day to day business. A fourth industrial revolution will not be complete before industrial additive manufacturing solutions exist in metal, polymers, and composite materials. There is an endless room to further invent.