3D printing or AM (Additive Manufacturing) technology is growing rapidly on a global basis, particularly in industrial sectors. According to Wohlers, which gathers statistics on the AM sector, in recent years the value of AM business activities has risen by over 30 percent per year. The sector was worth more than five billion dollars last year.
– This development has its origins in the research-intensive automotive, aerospace and pharmaceutical industries. We in Finland have caught up quickly, despite missing out on the initial stages. The industrial sector is extremely interested and new commercial printers are on their way, says Pasi Puukko, Research Team Leader of Advanced Manufacturing Technologies. The team’s special research areas include challenging development, design, processes and business activities associated with the 3D printing of industrial metals.
3D printing materials can be divided into various alloys, polymers and ceramics, and other materials such as food or concrete. There are great differences between professional and so-called home printing. Home printers for plastics vary in price and quality. The range of industrial printers and materials is wider and more expensive.
– 3D printing of metals is an area of strength for Europe. Pioneer countries include Germany, Italy and the United Kingdom. Strong expertise is also emerging in countries such as China, Singapore and Australia. The USA has strong competencies in the 3D printing of polymers and has invested in metal AM on a national basis.
From printing to manufacturing: Prototype, tools and finished products
Puukko stresses that 3D printing tends to progress in three stages in many sectors. First, 3D prototypes and visual models, made of plastic for example, are printed out. Unlike the following stages, this phase is already widely used by industry. In the next stage, tools and production equipment are printed for the company’s own needs. For example, VTT has collaborated with ABB in the 3D printing of parts used in an injection moulding tool for the production of grommets for frequency converters. In the third stage, end products are 3D-printed directly – these can be new products which could never have been imagined, let alone made, before.
Manufacturing for Design
The 3D manufacturing process still takes a fairly long time and the equipment is costly, which makes single products expensive. There are also limits to the size of printed objects.
– 3D enables the production of just about any shape without the limitations set by traditional production methods, providing completely new visualisation and design opportunities during product development. Additive manufacturing brings notable savings in materials compared to traditional methods, which may discard as much as 80 percent of the metal. Lighter and more sustainable components which, for example, reduce the fuel consumption and life cycle costs of aircraft, also save energy and the environment. Performance is improved, assembly streamlined and expedited, and local manufacturing is enabled. It is becoming easier to compare various 3D models and move on to the prototype testing stage. When problems are eliminated at the prototype phase, the entire product development chain is streamlined.
– Cost-effective use can be made of 3D printed prototype models in advance sales and marketing. Intensive work phases and expensive investments are introduced when sales have begun. The technology enables small, one-off production runs.
A shift is under way from production to design-centred models and holistic production management. In the future, there will be a continuous need for more experts in various new forms of production technology. 3D design should be included in the early stages of product design.
VTT’s vision – from products into bits
– The printing of metals is a major area for us, whereas 3D-printed food is an interesting, new direction. Our most-used 3D printer is a metal printer a couple of years old, but we also have others, says Puukko.
VTT’s vision is to go digital with all of its product life cycle planning and the related materials. In the future, there will be no need for physical prototypes. Products will be simulated and modelled on computers.
The Digital Spare Parts project, involving VTT, Aalto University and 14 Finnish companies, is currently under way. The project will involve the 3D remote printing of the spare parts of the future – according to need in the recipient’s warehouse. This will make them quickly available at the preferred location, releasing valuable capital tied up in stock. New commercial activities and revenue models are also being investigated. Cost-effectiveness is increased when, for example, spare parts for large machines can be obtained quickly.
Finland needs to be involved in such development, since the world is advancing fast in the use of 3D technology. Growth in printing speeds will reduce costs and provide new opportunities for industrial sectors in which the use of 3D printing was not previously rational.
ABB solved a cooling problem affecting a manufacturing tool
Senior Specialist Vesa Palojoki has been designing mechanics and products for 20 years at ABB. His duties also involve the design of 3D models and prototypes
– In the public Manu project belonging to the FIMECC spearhead programme, we collaborated with VTT on investigating whether we could use 3D to design and produce new cooling functions for a metal tool mould. Matti Mielonen of Aalto University completed his Masters thesis for ABB on the same subject. Solving this cooling problem would enable a major improvement in the manufacturing process and a leap forward in production.
A conical, injection-moulded rubber-like grommet with a diameter of 40 millimetres is needed, to enable the feeding through of ABB’s frequency converter cable. The part in question is critical, and it was selected for the first case study of ABB, from the group of many other parts alike. Manufacturing it is challenging, due to the softness of the thermoplastic rubber material, since the mould-injection tool used to make it could not be cooled sufficiently. The tool was originally produced using traditional processing techniques, i.e. metal was cut away. This placed limitations on the production of the required shape. In turn, the speed and quality of production were affected.
Production output triples
The complex channel part inside the tool has now been modelled. In collaboration with VTT, 3D printing was used to create various channel shapes and investigate their effects. 3D enabled the production of the tool’s cooling channels as a single structure. This clearly improved the cooling properties, since the cooling channels could made to run conformally with the product, inside the tool.
The cooling time was markedly shortened, and even cleaning of the inner channels of the tool was possible to retain. This has relevance from the tooling maintenance point of view.
Four rubber parts could be made per minute using the traditional method. Using the new technique, the same number could be made in 15–20 seconds. This is a major improvement.
– We solved the complex production process and the challenges involved in cooling the tool. Traditional methods do not present options as good as this.
– The Master’s thesis and VTT’s efforts have provided us with a sound knowledge base for the next application of this technique. We also know what we can ask for. We aimed to explore the possibilities of 3D printing because we are designers of finished products above all. You need to understand certain laws of design and technology in order to make product parts work. We now have a better understanding of what to order and demand from subcontractors and designers. The business aspect, such as the price and production time, are also relevant. Following the first case study made in cooperation with VTT, there have been three new tools under work by ABB using the same 3D printing technology.
This is no ivory tower exercise – it’s an investment in production.
CM Tools Oy, SLM Solutions GmbH and Vossi Group Oy also participated in the project.
ABB is a leading Swedish-Swiss concern in power and automation technology, which employs around 135,000 people in about 100 countries. The company has around 5,100 employees in Finland, where it has operations in 20 towns and cities.
ABB has a turnover of around EUR 2.2 billion and invested EUR 138 million in research and development in 2015.
We need to be able to question old ways
Veli Kujanpää, a professor at VTT, works as the Research Team Leader of the future-oriented Additive manufacture project under FIMECC’s Manu programme. He also participated in ABB’s project, on behalf of VTT. The programme involves promoting issues such as the utilisation of 3D printing by industry, in collaboration with Aalto University, Tampere University of Technology and Lappeenranta University of Technology.
– VTT was responsible for the 3D printing and parameters for the ABB project, and participated in planning and design. The thesis involved the design of channels and testing, which was done by ABB. Made of many parts, the previous version of the tool was laborious to implement as a test design solution. The H13 tool-grade steel proved challenging in 3D printing due to its hardness, the delicate nature of its smelting process and the precision of the required parameter control. These challenges were solved together. The result was a hard, durable and heat-resistant tool, which enables long mass-production runs.
Kujanpää believes that we must now question old approaches.
VTT Metal manufacturing: 3D-printing and Powder Bed Fusion
3D food printing:
Photographs: Sirpa Posti, Pasi Puukko, Asta Nurmela, Katariina Torvinen