Additive manufacturing (AM) allows us to meet these demands with almost no limitations on geometry and material selection.
The benefits of AM have never been more essential than they are now. As industries move to respond rapidly to the dangers and challenges presented by Covid-19, AM’s speed and flexibility has stepped centre stage. 3D printing (3DP) has been key to aiding car manufacturers, for example, to suddenly switch to producing ventilators or fashion companies to create PPE in place of handbags and suits.
From the start, AM claimed the crown as the most flexible production method going. And whilst 3DP is still considered a gimmick by the general public, new developments mean the possibilities are almost limitless.
A wide choice of materials, high speed, and the extensive possibilities for post- processing and measurement make 3DP an indispensable tool for making prototypes and small series – and an invaluable one in the fight against Covid-19.
Material choice
The various AM processes, be it the Multi Jet Fusion process, stereolithography or direct metal laser sintering, have led to an explosion of possible materials that can be processed using 3DP. The range extends from plastics to elastomers, such as silicones, and metals. Common to all processes is that the workpiece is created layer by layer and in most cases has to be additionally held by supporting structures.
The wide range of materials also means that prototypes produced by means of AM can be used in almost any field. Workpieces made of the particularly heat-resistant metal Inconel 718 by means of direct metal laser sintering are used, for example, in the aerospace industry. Copper shaped by the same process can be used if good electrical conductivity is required.
Most recently, AM came to the rescue when 3D printed valves for life-saving emergency ventilation masks were urgently needed. AM saw these parts rapidly manufactured and delivered to Lombardy, Italy, a hot spot in the fight against the virus.
High speed and creative freedom
3DP also enjoys such high regard within manufacturing due to the comparably high speed for rapid prototyping.
Where injection moulding requires creating a mould suitable for the respective workpiece then a great deal of time and technological effort to produce injection moulds tailored to the component, the desired part can usually be produced directly via 3DP with relative ease.
The only thing to be considered here is that the respective shape is optimised for AM, and more precisely for the specific 3DP technology being used. If, for example, there are overhangs, it is advisable to keep these as small as possible by using obtuse angles. By doing so, the required supporting structures can be kept as marginal as possible and the required material and the resulting costs are lower.
AM offers more flexibility than injection moulding or CNC machining. Tunnels located in the workpiece can be implemented during additive production, enabling geometries that cannot be realised any other way. This is especially beneficial in the production of prototypes, giving engineers and designers a great deal of freedom in the design of parts.
Though the demands on prototypes can vary, it is important that parts made by 3DP are checked after production and reworked if necessary. Most suppliers of 3D printed parts offer special testing and inspection services for this purpose, which identify even the smallest tolerances – sounding the alarm in the event of excessive deviations.
For example, at Protolabs, a specialist in the production of prototypes, 3D laser scanning technology and coordinate measuring machines can be used for this purpose, if required. With coordinate measuring machines, the physical geometry of an object can be precisely calculated by a sensor detecting points on the surface along three spatial axes. The volumetric accuracy here is (2.1 + 0.4 l/100) μm. With 3D laser scanning technology, the workpiece is scanned with a laser and compared directly with the CAD file used. The accuracy here is 0.01 mm at a sampling rate of 32,000 measurements per second.
Think freely
Rapid prototype production is increasingly vital. Ideas can go from brand new to essential for an entire industry within days. AM already provides cross-industry support in this area and can help in unlikely places by quickly providing prototypes. Whether for individual parts for use in essential goods or valves for emergency ventilators, AM allows the imagination of designers to realise the previously impossible. And this is exactly what the digital transformation is all about: to be able to think freely in every possible direction.
Find out more at protolabs.co.uk
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.