Applications of additive manufacturing in tool and mould making
26.11.2018
No, additive manufacturing will not replace mass production processes any time soon. However, as a supporting technology, it can improve mould-making processes drastically, upgrading manufacturing efficiency.
For several years now, there has been a lot of talk about disruptive innovations and technologies. A number of trends are said to be able to change the manufacturing industry forever. Smart manufacturing, digitisation, Industry 4.0 and lately also 5G are set to disrupt how we work. In all these cases, what is meant is that if the technology succeeds, it will change and transform existing markets and value networks. The problem is that no one can truly say whether a technology succeeds or not.
In 1996, Nokia presented the first smartphone to a world that was just not ready for it yet – or maybe Nokia's marketing team was not able to convince the world that it needed the smartphone. The company that was able to successfully launch the smartphone was, of course, Apple, nine years later. Many innovations have failed the test of time. Another example is Google Glass. Once praised as the next leap in consumer technology, it was discontinued in 2015 (There is however still a so-called Enterprise Edition for working environments.).
There are countless stories like this in technology – products that failed almost immediately. The interesting thing about the story of Google Glass is that it was hyped so much and finally had to surrender to real concerns: People did not like to be secretly recorded. That is the thing with disruptive technology. It might be groundbreaking and it might be innovative. But it is only disruptive if it eventually manages to change or displace existing markets.
Additive manufacturing and the hype
Additive manufacturing has also been praised many times as a game changer for the supply chain. It was said that 3D printing would lead to household production of goods, that there would be more local production instead of centralised plants. One very common news title was “3D printing will change the world”, followed by texts stating that “life on earth will soon change radically” and “instead of customers, we are now creators”. Those headlines are now more than five years old and it seems that the world is still pretty much the same. The hype was exaggerated, expecially concerning the influence 3D printing would have in our private lives. However, there are areas in which 3D printing is widely accepted as an important technology. It just has not reached the point where it replaces existing markets. Rather it enhances them. One reason for this is that additive manufacturing is not quite as simple as you might imagine. There are several reasons for this.
Additive manufacturing needs a broader knowledge base:
In many cases, knowledge of the various technologies and the associated advantages and disadvantages and applications is simply not available. Since many of these technologies have not been on the market for decades, it will take quite some time before the knowledge has spread. For example, only a few universities are really specialised in AM technology.
Additive manufacturing demands a rethinking of design:
It is very important to be familiar with this process. Before actual production, there is construction – and this differs clearly from the traditional subtractive methods, so much so that the design process looks completely different. This starts with the fact that support structures have to be included in the planning phase and continues with the fact that the company takes nature as its model and imitates bionic structures completely removed from the usual forms.
Post-processing: It doen't stop with printing:
Another building block is the knowledge of the process itself. How time-consuming are the construction phase, the production phase and the post-production phase really? How quickly can you hold a finished part in your hands? How long will it take to achieve the surface finish that is needed?
Additive Manufacturing in tool and mould-making
In toolmaking, additive manufacturing can be applied in different stages of the process.
Rapid Prototyping:
Rapid Prototyping is used to create physical models to review and validate a design. It is a typical application for additive manufacturing technologies as other methods are more cost-intensive. The advantage of using additive manufacturing here is that the model's design and functionality can be reviewed very quickly, thus reducing lead times.
Rapid Tooling:
Rapid Tooling is the method of producing a tool using additive manufacturing. This is especially useful when the tool is used to produce small series. A traditionally manufactured tool is often much too cost-intensive. If a tool is manufactured additively, it also has the same advantages as in rapid prototyping, namely, design changes can be applied more quickly.
Rapid Manufacturing:
Rapid Manufacturing does not apply additive manufacturing per definition. However, this manufacturing method stands for quick and flexible methods to produce parts without using tools. Nevertheless, it often involves additive manufacturing. Rapid Manufacturing especially makes sense when a part not only needs to be produced quickly but also has a geometry that is hard to realise with traditional methods.
Other applications in toolmaking:
Particularly in toolmaking, there are many other possible applications of additive manufacturing. While the aforementioned applications describe the direct production of either finished part or finished (prototype) tool, additive manufacturing can also be applied to manufacture components or parts. This may include producing mould inserts or even equipment needed to optimise the manufacturing process.
Another common application is the optimisation of the mould itself. Here, speed is not the decisive factor but rather the added possibilities that additive manufacturing offers. With additive manufacturing, cooling channels can be added to injection moulds that cannot be produced with traditional methods like millling and drilling. Using additively manufactured cooling channels within the tool, even areas that are difficult to access – for example, those surrounding the ejector and slider – can be cooled conformally. The injection moulding cycle can run much more quickly than before. As a consequence, cycle times in injection moulding can be reduced by up to 40% if the temperature profile is homogenised simultaneously.
Application examples for an efficient use of AM
These applications all represent extremely individual processes and solutions. The decision as to whether such an implementation is worthwhile for a company must always be made on a case-by-case basis.
In order to convey a good idea of what is possible, the case studies presented on this double page are evidence of how different companies use additive manufacturing in prototype, mould and toolmaking. The full stories of these use cases have been published on etmm-online.com and can be found there.