The AM Sustainability Issue. Dr Chris Tuck University of Nottingham

Transcription

1 The AM Sustainability Issue Dr Chris Tuck University of Nottingham

2 Agenda How do we answer the question: Is AM sustainable? What do we mean by AM? Are all systems the same? Key Attributes of AM Complexity of Design Location of Manufacture Example Concluding Remarks

3 What is AM? ASTM F42 defines AM as: Additive manufacturing is a process of joining materials to make objects from 3-D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies. Synonyms: additive fabrication, additive processes, additive techniques, additive layer manufacturing, layer manufacturing, and freeform fabrication. (ASTM F )

4 Industrial or Home Manufacturing? Muddied waters I am discussing AM in the industrial context not the Home Maker Movement For the following reasons: Does the average consumer make a sustainable manufacturer? On current evidence no waste food statistic 7.2 million tonnes p.a. Control of production and resource is dissipated Logistics and supply Manufacturers have a key requirement Efficiency is key in production, material, energy and design etc.

5 The Sustainability Question? Is AM Sustainable when compare to traditional manufacturing technologies? As ever it s not quite as simple as it seems &

6 Machine Type Variants The misconception There is no single AM or 3D Printing Technology This makes it difficult to give an accurate answer

7 Why is AM important for Sustainability? Traditional Manufacturing AM Subtractive Results in waste material and suboptimal geometries Formative Efficient material but sub-optimal geometries and tooling requirements Supply chains globalised logistics chains, movement of material and value all over the world Waste streams affected but not eliminated Geometry affected Supply chains affected

8 Holistic Analysis Process energy consumption in Life Cycle Analysis (LCA) Design Affects the Cycle Adapted from PAS 2050 MJ per kg deposited

9 Manufacturing Energy Consumption Single part build One part placed in the centre of the work space Full build As many parts as possible placed in the work space 2D or 3D build volume packing

10 AM Machine Energy Consumption - Polymers and Capacity Full capacity utilization has a dramatic effect in LS ( % energy consumed per kg) This is due to significant warm-up and cool-down energy (135 MJ) Full capacity utilization has a small effect on FDM energy consumption (-3.17 %) This indicates that FDM can be used efficiently in a serial mode of production Left columns: Single part builds / Right columns: Full builds

11 Sustainability issues for polymer AM systems Energy consumption of the machine is not the whole story Laser Sintering Material feedstock recyclability Not 100% reused or utilised contains huge embodied energy Fused Deposition Modelling (FDM) Support material wastage Speed of system Mode of Serial manufacturing

12 Metallic AM Machine Energy Consumption Metals systems: Left columns: Single part builds / Right columns: Full builds

13 Sustainability issues for Metallic AM systems Energy consumption of the machine is not the whole story Material feedstock is generally recyclable However, there is support material wastage and surface finish requirements Normally requiring post-production steps Speed of system E-Beam systems show this in their productivity Laser Systems need, and are, catching up

14 Effect of Efficiency Efficiency gains are realised through operation at full capacity for all platforms, especially those with warm-up and cool-down cycles Parallel production rather than serial is a key benefit

15 Key Attributes - Design Complexity of Design Significantly enhanced Design can make or break the sustainability case for any AM component / case study

16 Key Attributes - Location Location of Manufacture All you need are a machines, personnel, materials and energy. AM can be localised but should it be? Global supply chains are efficient Localise on necessity and capability rather than as a default Standards and manufacturing control / quality Are product miles the new food miles?

17 Example for SLM - Virgin Monitor Arm

18 CNC vs SLM Compare CNC with optimised AM (Long haul aircraft 30 year lifetime) Through lifecycle saving of 54.3tCO 2 e equivalent to 20,000 litres of JetA1 over lifetime of the aircraft ($22k of fuel) 40 seats on a 747 ($880,000 fuel saving) Original Part Optimal for 68kg Material Route Weight Raw (kg) Part Weight (kg) BTF Phase GHG Emissions ( 000 kg CO 2 e) Raw Material Man f Trans p Use Disp Total Ti6Al4V CNC % 0 Al CNC Ti6Al4V SLM % 0 Al SLM

19 Conclusions Manufacturing energy consumption is not enough to make the case A holistic viewpoint is essential to show the validity of the approach AM allows material efficiency and design efficiency that has a much greater effect on the product lifecycle AM can enable sustainable manufacture But only when the case (business and technical) is right The environmental benefits for AM can be significant

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