Maurizio Bernini, Product manager for Additive Manufacturing and New Technologies at CMS SpA

After graduating from Politecnico di Milano with a degree in Nuclear Engineering, Maurizio Bernini dedicated himself to applied research and the technical and commercial development of products and technologies. From 2002, he contributed to the development of CMS in the composites industry.

JEC Composites Magazine: Why did you choose additive manufacturing?
Maurizio Bernini: “In 2016, a customer operating in the aerospace sector purchased an “aerospace-grade” CMS portal to machine large 3D-printed polymer parts. So we asked ourselves: Could we provide a complete solution, including additive manufacturing and milling?

From there, the story began: scouting to select an R&D partner, signing an agreement with Fraunhofer IWU in September 2017, developing R&D packages, launching CMS Kreator Ares in 2021 and starting sales.

Now we are about to launch a Kreator version equipped with a 100 kg/h extruder (the current extruder has a massflow of 10 kg/h), installed on a Poseidon portal.”

JEC Composites Magazine: What type of parts can be produced with LFAM and what are the economic benefits of this technology?
Maurizio Bernini: “LFAM (Large Format Additive Manufacturing) technology is used to manufacture tooling (machining jigs, lamination masters and direct moulds for composites) and other parts in order to replace epoxy, ureol or similar materials as well as deposition modelling (FDM) processes.

The main economic benefit is material saving. The images show some parts exhibited at Formnext 2021, JEC World 2022 and Formnext 2022. The material savings are highlighted in some captions.”

JEC Composites Magazine: What are the mechanical characteristics of the material and the durability of the moulds? Which technical problems does AM solve?
Maurizio Bernini: “Basically, the material used is plastic, thus the mechanical features are not adequate to withstand high stresses. Just to have an idea, the Young’s modulus of steel is around 200 GPa, that of aluminium is around 70 GPa while that of polypropylene, a polymer widely used in automotive applications, is less than 2 GPa.

The addition of short carbon fibre can increase mechanical properties (for example, the Young’s modulus of PA6/CF40 is 13.6 GPa), but not that much. On the other hand, it adds anisotropy due to the fibre orientation. Therefore, you can realize why the most popular use of LFAM is tooling manufacturing.

A crucial feature of the materials used for LFAM is the glass transition temperature (Tg). That is, the point at which the material starts to weaken when the temperature rises. The Tg of a material tells us if it is suitable for use in an autoclave (typical temperatures: 75°C, 120°C or 180°C). Therefore, there are basically three classes of materials for AM: room- or low-temperature, intermediate-temperature or high-temperature materials.

The durability of moulds depends on the material used. According to suppliers, intermediate- and high-temperature materials can be used for hundreds of cycles.

The technical advantages of LFAM are different depending on the sector where it is used.

Using LFAM to produce machining jigs not only results in material savings, but also in energy, time and labour savings due to the shortening of the process. For instance, it is no longer necessary to roughen the boards, glue them, wait for the glue to solidify, etc. Machining is reduced because the resulting workpiece is “near-net-shape”.

LFAM manufacturing of direct moulds for composites dramatically shortens the process, skipping the composite mould manufacturing step.

In an FDM replacement context, LFAM reduces the cost of materials (filaments are about 5 times more costly than granulates, with the same polymer) and the number of subparts due to the larger build volume. Which implies less energy, time and labour.”

JEC Composites Magazine: What is the environmental impact of AM? 
Maurizio Bernini: “Everything we have previously talked about suggests that LFAM should have a lower environmental impact than traditional manufacturing methods. But in a holistic view, with supporting data, what about the overall environmental impact of a process using LFAM?

We commissioned the consulting company RINA for a study focused on direct moulds for CFRP, 3D printed and milled with CMS Kreator. The study compared the usual CFRP mould manufacturing process and LFAM production of the polymer mould, examining all the incoming energy streams and outgoing waste to be disposed of.

The results are interesting. The process using LFAM reduces the environmental impact of production by 55% and when considering the product recycling, the environmental impact is more than 60% lower.

The greater sustainability of processes using CMS Kreator is certified.”

JEC Composites Magazine: How do you see future developments in the aerospace, automotive and marine sectors? 
Maurizio Bernini: “It takes up to ten years to validate materials and technologies for the aerospace sector. Since LFAM was born in 2014, we will have to wait some time to see its widespread use in the sector. Priority will be given to the least critical process, the production of large jigs.

Due to their extensive use of CFRP, luxury vehicles and racing cars should be rapid growth sectors for LFAM.

The production of luxury yachts should also greatly benefit from the manufacturing of direct moulds with LFAM, but the sector has orders to fulfil until the end of 2024, so widespread use of the process will take place gradually over this period.”