by Geoff Gould
SAMPE UK and Ireland Chapter, Annual Seminar and Tabletop Exhibition – Virtual 10th and 11th March 2021, Hosted by The University of Edinburgh
Due to the restrictions posed by the pandemic it was decided to go ahead as usual with our annual seminar, but in the form of a virtual event. Despite the new communications challenges, we are pleased to report that the seminar was a great success with over 120 registered delegates, 11 presentations and 10 tabletop exhibitors. Our special thanks go to our financial sponsors: Surface Generation, Bright Lite Structures, Materials and Manufacturing Technologies Magazine (M&MT), CNC Robotics Ltd and The University of Edinburgh (UoE). We acknowledge the important participation of all our tabletop exhibitors, the names of which are listed at the end of this report, and who provided pre-recorded short videos of their company’s activities, which were shown in breaks between the presentation sessions. Finally our thanks go to our SAMPE Events Team Sub-Committee headed by Conchúr O’Bradaigh (UoE) for organising the programme, and to Katrina Saridakis and Emily Martin (UoE, Research Institute Services) who provided and supervised the communications software platform which enabled the seamless interaction between delegates, speakers, sponsors, and exhibitors.
1. Session 1: Wind Energy
- Andrew is Senior Director of Manufacturing and Engineering leading a global team of 175 engineers. LMWP has 13 factories with a total of 13,000 staff, and has been manufacturing blades for 25 years. They have produced nearly 0.25 million blades in total, with 13 thousand blades in 2020, mitigating 250 million tonnes of CO2.
- The presentation highlighted the development of blade length from 7 metres to the current longest blade of 107 metres. Originally most wind turbines were on-shore but there is a shift to off-shore installations. The transport difficulties associated with the longest blades require a factory location close to the installation site, hence these factories are now at the coast.
- There has been an exponential rise in blade length from 20m (1980) to 107m (2020). LMWP is a large user of composite materials with a typical annual consumption of: Reinforcements (130k Tonnes), Resins (95k T), Cores (150k m3). The challenge of blade length is not restricted to transport logistics. The moulds are massive and are completely automated regarding tape-laying positioning, adhesive bonding of joints and closure. An operator can walk up to 5km per shift, in say 15 inspections of the mould, from hub to tip. Blade-handling requires special equipment because the longest blades are heavy (nearly 50T) but they are also delicate. The fast turn-around time is approximately one blade per mould per week. Production rate is driven by the world’s escalating need for transition to zero-carbon energy.
- For the future, increased tip speeds present a continuing design challenge. Longer blades require stiffer structures using H-glass fibres and carbon fibres in stiffness-critical parts of the blade, but never 100% CF due to cost. Further investment in advanced processes and automation is underway. Design life is of the order of 25 years but end-of-life issues aim for fully recyclable blades, with a probable greater use of thermoplastics.
- Shortly after the presentation GE Renewable Energy / LMWP announced publically that Teesside has been selected as the location for a new factory to build the 107m blades with the creation of 750 new direct jobs plus 1500 indirect jobs. We send our congratulations to LMWP.
2. Session 1: Wind Energy
- Peter is Chief Engineer for Energy at NCC Bristol with 13 years experience in composites R&D. Energy is a rapidly changing sector with the ambitious target for zero CO2 emissions. NCC is part of 7 R&D centres focusing on pre-production applied R&D in the development range TRL 4-6. The “Horizon” energy project is a 10 years programme involving many industrial partners, including the fossil fuel giants, Shell and BP.
- The presentation focused on three main areas: (1) Off-shore wind – Horizon 1 (work underway), (2) Pressure systems – Horizon 2, (3) Off-shore structures – Horizon 3 (10 years duration).
- Work is underway to define the technologies needed for the manufacture of giant turbines with very long blades in excess of 100m. This wide-ranging project includes design, materials, smart blades, reducing manufacturing waste, and recycling. Right now, more waste is incurred in manufacture than is recovered in recycling.
- Giant turbines require proportionately large support structures which in turn require novel designs, including XL Floating Turbines, together with improved anti-corrosion properties for extended lifetime. To date thermo-set resins are used mainly, and NCC advises that these materials still have development potential. Thermoplastic resins show great promise and will facilitate end-of-life, but more work is needed to exploit. To continue the “green theme” NCC is looking at recycled carbon fibres but more confidence is needed in their variability.
- Pressure systems comprise both cylinders and pipes and whilst originally the containment requirement was for hydrocarbon gas / fuel, development is needed for the transport of H2 and captured CO2. Off-shore H2 pipes need a hydrogen-resistant matrix with thermoplastic repair capabilities.
- Success in the energy transition industry requires three prerequisites: (1) quantified sustainability (2) robust data and communication (3) mature and reliable delivery.
3. Session 2: Sustainability
- Dipa is a Senior Lecturer at UoE with 23 years’ experience in composites. Her presentation described two projects aimed at enhancing thermoplastic properties: (1) modified acrylic matrix (2) bi-component fibres.
- Thermoplastics have many useful properties but high viscosity is a major drawback in fabrication. Work focused on ELIUM thermoplastic acrylic matrix which has a useful low viscosity but is amorphous and therefore has attendant poor properties: solvent resistance, creep, thermal mechanical instability and embrittlement.
- The effect of adding 5% polyphenylene ether (PPE) was examined .The solvent resistance is excellent using a soak test of 72 hours in acetone: Acrylic 28% weight loss; Modified Acrylic 2% weight loss. This excellent solvent resistance is due to molecular cross-linking with the PPE, which did NOT adversely affect either the thermo-formability /recyclability of the mixed resin, or the viscosity compared with the base-line pure acrylic.
- The second part of the presentation summarised work on thermoplastic bi-component fibres, a project run in conjunction with I Comp, Limerick. Bi-component fibres were spun with a non-melting core (i.e. a higher m.pt.) and an easy-melting sheath. Polyester (PET) and polyolefins (PO) were studied as the core material, with a sheath of PPE. Composites were made from both 100% self-reinforced bi-component fibres and with added glass fibres: 18% GF / 32% PET core / 50% PPE sheath. An optimum level of composite strength, modulus and toughness is produced from an appropriate blend using conventional thermoplastic processing.
4. Session 2: Sustainability
- Kevin has a strong automotive background in the luxury car sector (e.g. Aston Martin) and since moving to FAR-UK is involved with a broad range of automotive and aerospace projects. He stressed three prime inter-connected factors which underpin all sustainable composite applications: (1) Made by Robots – i.e. don’t just consider automation (2) Led by Analysis – from initial design and onwards (3) Circular Economy – make the most of what resource we have.
- The rapidly changing trend for vehicles is: Standard →Low Weight →Electric. It is important to recognise that in this trend towards a green environment, CO2 emissions often actually increase in manufacture, whereas in use they fall as expected. This is the equation to balance to achieve the required net effect; it is not just about choosing the “best” materials with the highest mechanical properties and operating temperature range. For materials, the factors to balance are Energy Use / Mechanical Performance / Cost. The true cost and environmental impact of a product is given by the total energy in lifetime. Here is where the “circular economy” is important.
- Kevin advised that the “business model” is more important than Government legislation. The business model starts with the design – for extended use, re-use / re-manufacture, and recycling, with the latter as a last resort.
5. Session 3: Automotive
- Tom is Head of Technology and Applications based in Durham, with an impressive background in automotive with Volvo, BMW and others. Gestamp is a Spanish company with manufacturing in 24 countries, 13 R&D centres, sales of €7.5 bn and 40,000 employees. They make bodies, mechanisms and chassis. Their core business is steel and hot pressing, but they are also large users of aluminium.
- Gestamp has a 3-5 years project to address chassis development for electric vehicles, which includes composite materials. The chassis is a safety-critical structure in which stiffness, strength, durability all affect driveability and safety. These requirements are common to both I.C. engines and electric / battery cars. The battery adds from 250 to 600 kg to the weight of the car. Noise needs addressing – the engines are quieter, so the road noise increases (although composites will mitigate NVH).
- The light-weighting project to reduce CO2 is in three areas: (1) Innovation and Design (2) Materials Selection (3) Design for Manufacture. Gestamp acknowledge that composites have made significant inroads into automotive design: Luxury Supercars → Luxury volume Cars → more Mainstream, but cost is a limiter to volume use. Composite chassis parts were shown made by compression moulding and over-moulding. Multi-structures and hybrid structures (steel / composite) were shown with 35% and 44% weight saving compared with 100% steel.
- But the role of metal in bulk electric cars is far from over. Steel continues to give excellent weight / cost performance for volume cars and continues to be the majority material in the total market. Work on the sustainability of aluminium technology, metal corrosion resistance and manufacturing innovation continues in parallel with composites development. Gestamp focus on whole life cost for the time when electric vehicles become standard at volume.
6. Session 4: Transportation
- Mark is Chief Operating Officer for Technology at Artemis. Originally engaged in aerospace, he has automotive experience with both road cars and racing cars with Williams F1. He joined Artemis full-time in Year 2020.
- Maritime transport contributes 2.5% of total global emissions equivalent to 1000m tonnes CO2 per year. The International Maritime Organisation (IMO) legislates that emissions must reduce by 50% by Year 2050. Maritime needs to catch up with aerospace and automotive.
- Artemis is the lead in the Belfast Maritime Consortium Partners involving a £53m programme with 12 partners, with the aim of producing zero-emissions commercial vessels. The test-case is the first “autonomously controlled, fully submerged, electric hydrofoil” for service as a commercial ferry. (note, “fully submerged” means a ferry which spends all of its time in the water, as opposed to a conventional ferry which discharges, loads and parks on shore).
- A video was shown of the Artemis eFoiler, a racing composite catamaran which incorporates a number of features used in the hydrofoil. A primary environmental advantage of a hydrofoil is that because it flies over the water, there is very low drag and increased engine performance resulting in up to 90% fuel saving. Since the vessel is lifted up, the use of lightweight composites is essential. The design is based on future-proofed technology and is easily scalable. Other advantages include: a comfortable ride (compared with a bouncing conventional ferry), no wake and hence no bank erosion, and zero emissions using a hydrogen fuel cell.
- An 11 metre demonstrator will be complete by the end of 2021. Artemis has invested $250k in the project which will produce the first full-size vessel in 2025. The specification is: Length 25-40m; Weight 90-100 tonnes; Speed 35 knots.
7. Session 4: Transportation
- Elspeth is a Research Fellow and has been at WMG for 10 years. This project grew from the acknowledgement of the sharp decline in the use of public transport, especially since the start of the pandemic, due to the general public’s perceived danger in exposure to the virus from touching much-used surfaces. The grab poles on buses were selected as a most appropriate focus for development. Composites lend themselves to accommodating additives and have the added advantage of low weight.
- WMG lead a team including Composite Braiding (Derby), Heath and Safety Executive (HSE), Transport Design international (TDI), and two bio-companies: Bio Cote and Promethean Particles. Braiding was selected as the best method for producing tubes in high volume.
- Glass fibre / Nylon PA6 was selected for ease of manufacture, cost, and performance. Pre-impregnated tows are wound and then consolidated by rapid vario-thermal moulding.
- Two types of anti-microbial chemicals are being investigated. The first contains silver ions and is applied to the surface as a bio-coat. The second contains copper nano-particles which are mixed in with the paint.
- The anti-microbial efficiency of the composites is being tested at HSE laboratories. The effectiveness against both bacteria and viruses will be tested; most expertise at HSE is with the former.
8. Session 5: Innovating – Part 1
- Antony has a strong automotive background starting with March Engineering in1985, and later with McLaren and Bentley. He founded BLS in 2015.
- The fabrication techniques used in earlier production successes with BMW, Zenos, aircraft seats and parts for trucks and buses were summarised. Essentially the breakthrough technology is how best to make a precise complex 3–D shape from a flat panel. The use of recycled short carbon fibres in the skins facilitates fibre slip and enables controlled 3-D contouring. The skins are typically on a PU core and a special spray head delivers up to 7 components including epoxy and PU resins, pigments and mould release agent.
- This presentation focused on a recent development with Tesco supermarket delivery trucks. The component is the floor of the truck, and must be perfectly flat. Two fundamental criteria must be met: the maximum truck weight is 3.5 tonnes and therefore a standard driving licence can be used. A total of 39 prototype floors have been made, 4.2m x 2.2m. Some small metal fixtures are required and these are easily melt-bonded in to the core. Advantageous drip channels are inserted in the composite floor, which the metal floor does not possess. Robotic trimming and drilling is used.
- The composite floors save a remarkable 60 kg weight. The trucks are weight-limited, not volume limited. Since the average shopping lot is just 6 kg the payload is greatly increased. Tesco has placed an order for 1500 floors during 2021. Right now the floors are stiffer than the chassis, and springs are used to control the chassis roll movement. The next floors will be thinner and therefore even lighter.
9. Session 5: Innovating – Part 2
AFP Pre-forming for Improved Impact Tolerance. Rutger Kok, University of Edinburgh.
- Rutger won 1st prize in the 2020 student seminar presentation (virtual) and was invited to present today. Second prize was awarded to Jasmine Bone, University of Surrey.
- Out-of-plane impact damage (ID) often limits the increased use of composites, especially in aerospace. The three normal remedies: 3-D weaving, Z-pinning, stitching, are difficult to introduce and often reduce in-plane ID. Rutger introduced “Interlaced Composites” using Automated Fibre Placement (AFP).
- In a multi-directional composite some of the mechanical benefits of the anisotropy do not fully translate. AFP is easily modified to leave gaps between the tows; then fibre layers in different orientations are introduced, before the gaps are then filled with 0° fibre, and then the process repeats. Quasi-isotropic and 0 /+60 / -60 lay-ups were studied. Interlacing had the desired effect with only a small reduction in strength, modulus and in-plane ID, which shows interlacing to be a much superior process to the three normal remedies.
- Modelling of the lay-ups shows no easily identified repeating patterns, so care is taken to select a “typical” section of composite for testing. Numerical modelling was explained and the model was shown to be in good agreement with test results for strain effects, strain failure and mode of failure.
10. Session 6: Innovating – Part 2
- Alasdair is a mechanical engineer formerly with Advanced Composites Group but for the past 5 years he has been a Director of SG, which has 25 employees. SG’s business is in making and selling process equipment for plastics and FRP for enhancing product performance. They service right across the different markets with predominantly export sales. Their special expertise is in localised and rapid thermal control.
- The equipment comprises three parts: Control Panel; Tool Base; Zoned Tool Face. The latter is the only bespoke part, tailored to the geometry and nature of the component. The zoned, independently temperature controlled, tool face enables, for example, the uniform cure of a variable cross-section thermo-set part. In this presentation SG focused on the use of their technology in the uniform thermal control of thermoplastics, in both injection moulding (IM) and thermoplastic over-moulding (TPO).
- AR explained the fabrication of an aerospace component using thermoplastic bulk moulding compound (BMC) in which the long chopped fibres offer a bridge in performance between IM and conventional compression moulding. There are two challenges to uniformity: the high resin viscosity (melt 350°C to 420°C) and the fact that the material is initially thermally insulating. Localised thermal control mitigates these problems, facilitates mould- filling and elevates the properties of the composite.
- A separate project was described to evaluate the effect in the TPO process of improved thermal control of melt temperature (and related pressure) on joint strength. Bindatex tapes were injection over-moulded by SG using three different tools: flat pack, spiral pack and joint pack, and the panels were tested at Nottingham University which showed the high integrity of the joint.
- AR ended by describing current work on “wearable technology” which means, virtual reality (VR), augmented reality (AR) and mixed reality (MR). These products are used for a whole range of applications including the arts / design, electronic interactive games, and in the industrial market for on-the-job training. A huge growth in the combined market is forecast which demands thinner optics, reduced mass and very low warp. SG’s technology addresses these requirements very well, in addition to accommodating component complexity and scale-up. Thermo-sets will be used for prototyping and thermoplastics will be used for volume.
11. Session 6: Innovating – Part 2
- David is a chemical engineer and is Head of Materials and Processing at Lilium GmbH which he co-founded in 2015 and which has 600 employees. His has an aerospace background including a former senior position with EPIC Aircraft in USA.
- Lilium is addressing the challenges of a world increasingly urbanised, congested and polluted. Some 29% of emissions derive from transport. There is expected to be large growth in the need for green air travel. Having considered all options for aircraft type (fixed / rotary wing) and flight range, Lilium selected a short-haul regional fixed wing aircraft with electric / zero emissions power, low noise, and with the capability for vertical take-off and landing, i.e. eVTOL.
- A video was shown of a flying 5–seater prototype, range 300km, speed 300 km/hr. Conventional ailerons make the aircraft highly manoeuvrable. Safety is paramount, and successful design, rapid prototype development, and volume production rely on a number of key features: ease of inspection, which facilitates quality control, automation, and an established public data base. Automated processes, as currently used for automotive are envisaged.