«I see a bright future for composites»

by NICOLA CATENARO

Our portal continues the journey to discover the future of composites and the links that these still innovative materials have with the issues of sustainability and the environment. We interviewed Professor Christian Kukla from the Industrial Liaison Department of the Montanuniversita in Leoben (Austria). Here's what he answered.

Professor Kukla, what are the current strengths and weaknesses of additive manufacturing?
«There are several strengths of additive manufacturing. The first one is the freedom in design. This freedom can be used to tackle with the technical performance of a product, e.g. complex inner geometries for nozzles or insert for injection moulding tools, or with the aesthetical performance. A second one is the flexibility of this way of manufacturing, which is best shown by its planned use on Moon or Mars. There additive manufacturing allows the production of a wide variety of parts with one machine. One weakness is that additive manufacturing is basically expensive and in production a slow manufacturing process. Therefore, if a product with a certain design can be manufactured economically with more traditional manufacturing processes then it makes usually no sense to think about additive manufacturing. A second weakness is that additive manufacturing is still a developing manufacturing method, regardless which type of additive manufacturing. I expect a first maturity around 2030, meaning that you don’t get much better solutions nearly every year».

Biomaterials and recycling became an essential topic when it comes to sustainability. How important are these issues and how do you approach them?
«Both topics are important but have to be approached with common sense. Biomaterials nowadays have a certain variety of meanings. If one sees them as biodegradable materials then they will occupy a certain niche but would not be the main stream of materials. The point is different when biomaterials are defined by being based on renewable resources at the same time including recycling to ensure that materials are not lost as waste but forming a new source at the end of their lifetime. Regarding this circularity, which is realised in nature already, we are at the beginning. This means that even with big efforts it will take years and decades to achieve major improvements. Nevertheless, we have to undertake these big efforts because the longest journey starts with the first step. Or the other way round, if we do not make the first step we will not reach the goal».

Plastics or composites like carbon or glass fibre are both materials of the future?
«If you look at nature, there you will find, more or less, only composites usually consisting of polymers and ceramics, e.g. our bones and teeth. Metals are only used as trace elements, but play an important role here, e.g. iron in our blood. Based on this view, I see a bright future for composites. They are also used to process metals and ceramics like in metal injection moulding or in additive manufacturing where highly filled polymers are used in filament printing or also in vat photopolymerisation».

What are the sectors in which the use of composite materials could grow in your opinion? And for the plastics?
«We have the long-term trend of integration of functions since decades. This trend involves that each of our parts and products are showing more and more functions. Therefore, this development is observed in nearly every sector. I want to emphasise two key developments here. The first one is the development of smart materials, which could be single materials or composites. A lot of them are in the labs of universities and research institutions but will come more and more into the market to realise smart products or at least smart functions in a product. The second development is the combination of especially polymers with electronics, sensors, and actuators. A key word here are the so-called wearables. A lot of them are already in the market, e.g. in augmented reality. Also here, we are at the beginning. Thus, we can await a lot of innovations and new products».

What kind of additive manufacturing process will we use in twenty years? Try to imagine also what kind of products we could make with AD.
«For the coming twenty years I expect that the existing additive technologies will be improved and adapted to certain markets or ranges of products. These improvements include real innovations not to be foreseen now but will be based on the core additive technologies we have already nowadays. A key line of innovation is the development of materials especially for certain additive manufacturing technologies. This kind of development started already for SLM of metals and VPP, but will be the case for the other technologies, too. In twenty years, we will have a new trend in manufacturing. This will be the first line of manufacturing technologies similar to the way nature is doing it. The part is produced at the same time when the material is produced as a tree is growing».

WHO IS

Christian Kukla is working since more the 25 years in the fields of injection moulding, Powder Injection Moulding and Additive Manufacturing. There he is doing research and technology & knowledge transfer. Here he is engaged in many national and international projects dealing with plastics, compounds, plastics processing especially Powder Injection Moulding (material development and rheology of highly filled polymers), Additive Manufacturing and the development and implementation of sensors/actuators into the injection moulding process. One core expertise lies in the development and characterisation of polymer mixtures used for processing of metal or ceramic powders.