The Role of 3D Printing within Industry
There have been many hypotheses made about how 3D Printing/Additive Manufacturing will revolutionise the way we make products and how companies will function. Before we examine these, we should clarify what the technology is and some of the terminology being used.
3D Printing or Additive Manufacturing is a method of producing objects by successively adding thin cross sections of material until a 3-dimensional shape is produced. The media tends to use the term 3D Printing whereas Additive Manufacturing is used more in industry. Many people use the terms 3D Printing and Additive Manufacturing interchangeably. There is a subtle difference but for most people it is not worth bothering about.
Additive Manufacturing is quite different to conventional manufacturing processes where:
· material is removed as in machining (subtractive)
· material has its shape changed to produce an object such as in casting, injection moulding, forging and sheet metal forming (formative)
· components are joined together to provide a more complex object (assembly)
There are 7 basic Additive Manufacturing processes but one of the earliest was launched in 1987 and involved the use of a laser to selectively solidify a UV sensitive resin. The commercial name was Stereolithography but the ‘family’ name for this process is now VAT Solidification as the resin is contained within a vat. When this process became popular in the early 1990’s it was mainly used to manufacture prototypes and alongside alternative processes became known as Rapid Prototyping. In the 1980’s it would typically take 6 to 9 months to make a prototype of a complex plastic part whereas a Stereolithography part could be made within a week. Hence the term ‘Rapid’.
However, a study in 1996 at the University of Nottingham showed that these processes could be economical for making plastic parts in volumes up to 6,000 and so the concept of Rapid Manufacturing was born. Given that the actual production speed was much lower than processes like injection moulding the name was soon changed to Additive Manufacturing. The assumptions made about Additive Manufacturing tend to be either technical or commercial.
A common technical assertion is that Additive Manufacturing can make any geometry. It is true that much more complicated shapes can be made within a single process and geometries can be now made which would have been impossible previously. However, it should be remembered that each process has its own capabilities and limitations, especially concerning accuracy and the surface finish of objects. Companies are using the technologies to reduce the number of parts within an assembly and to manufacture objects with much more efficient flow surfaces either internally or externally.
It is often believed that Additive Manufacturing is much ‘Greener’ and that there is no wastage of materials. Generally, Additive Manufacturing uses more energy during the production process but as parts can be more easily light-weighted their use in objects that accelerate or decelerate can lead to great energy savings which far outweigh the extra energy used in production.
There is a great deal of interest in using Additive Manufacturing to make objects in multiple materials and probably one of the ultimate examples of this is the work to build replacement organs such as liver, heart etc. Although there is much research being undertaken in this area it is likely to be decades before this is done successfully. However, the medical applications will ultimately be the main area for these technologies. In the short term, the more likely area for multiple materials will be parts that require different mechanical properties or embedded electronics.
A few leading industry people have predicted that Additive Manufacturing will replace conventional manufacturing processes such as Injection Moulding. This is certainly impossible in the foreseeable future as too many technical restrictions currently exist with Additive Manufacturing processes and there is no real indication of them disappearing.
There has also been speculation that the use of Additive Manufacturing will lead to large scale reconfiguring of supply chains where all manufacturing takes place close to the point of consumption. There is some limited evidence of this occurring such as where products are redesigned and several components amalgamated. For companies making just a few of these amalgamated components then a threat certainly does exist.
One of the wilder theories is that customers will undertake their own manufacturing and that this will take place within the home. This is unlikely to happen because the technical capabilities of a ‘home 3D Printer’ will not be sufficient and also there will be little motivation to do this. Why would anyone want to print a part at home when they can get it same day or next day from Amazon? However, there will be a small number of examples where it might make sense to print objects within the home. An example of this could be pharmaceutical pills. Research at the University of Nottingham has already led to the ability to print multi-drug pills where the sequence of release and also the rate of release can be controlled. It would be fairly easy to design a home printer the size of a small coffee maker that could print pills. The difficulty is mainly in determining the new business model for the pharmaceutical companies.
Custom manufacturing is also another area where people have suggested that products will be made for specific customers. This is already occurring in the medical area for implants. The area where this has become the norm is ‘in-the-ear’ hearing aids where over 90% of world production uses Additive Manufactured shells that fit a specific customer. The dental area is following closely and it is believed that about 30% of crowns, bridges and implants are now made by Additive Manufacturing. Other areas with activity in customised Additive Manufactured products are fashion, jewellery, home furnishings, automotive sports and defence.
Although many claims regarding Additive Manufacturing are overstated it is certainly true that the technology provides great opportunities for companies to make new products which are more efficient, have higher value and make more profit. The key to this is understanding where it makes sense to use Additive Manufacturing. The benefits are not just in a few sectors but almost every sector and they are also not company specific but individual part specific. I would strongly advise companies to gain an understanding of the various Additive Manufacturing technologies and then undertake and audit of where and how they can be used to produce products.
Director Added Scientific
Professor of Manufacturing Technology, Faculty of Engineering