Our Insight video series will help you master digital manufacturing.
Every Friday we’ll post a new video – each one giving you a deeper Insight into how to design better parts. We’ll cover specific topics such as choosing the right 3D printing material, optimising your design for CNC machining, surface finishes for moulded parts, and much more besides.
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Insight: Covid-19 Case Study
Hello and welcome to this week’s Insight.
Over a great number of Insight videos I’ve given you all sorts of information to help you design prototypes or parts for injection moulding, CNC machining and 3D printing. There have been do’s and don’ts, advice about material selection, how to bridge supply gaps and lots more besides.
But this week I’m going to do something a bit different. You’ve heard all about the theory, but what about the practice? I’m going to show you how we helped Mercedes-AMG use rapid prototyping and on demand manufacturing to produce urgent CPAP devices for Covid-19 hospital patients to help meet the tightest of critical deadlines.
We talk about speed to market all the time, but never has it been so crucial as for the development of medical equipment to fight this pandemic. I think that some of the lessons that we have all learnt could change the way that supply chains operate in the future.
But back to the case study…
When we were in lockdown, Mercedes-AMG High Performance Powertrains worked with University College London to develop a new Continuous Positive Airway Pressure system or CPAP. These devices work by pushing an air oxygen mix into the mouth and nose to keep airways open and increase the amount of oxygen getting into the lungs.
The devices are less invasive than ventilators and helped ensure that only the most serious cases used the limited number of ventilators available.
The challenge was always going to be how fast Mercedes could develop such devices. To meet this challenge Mercedes needed a supply chain that could rapidly develop the tooling and then injection mould and deliver the parts in a really short time span.
At Protolabs we got a call to develop two new tools to make ten thousand brackets that hold the device next to the patient’s bed and a tool to manufacture a cap to shield the air entry for this new equipment.
Our software analysed the CADs for all these parts for manufacturability and we calculated the automated turn time developing the tools. We managed to speed this up on manual inspection due to the urgency of the project.
There were four quick prototype iterations for the brackets and some slight adaptions to the cap. We needed to produce parts that would both work and that we could manufacture rapidly to meet the demand for 1100 daily parts. In the end we used one tool with two cavity moulds to meet the production run schedules and give Mercedes complete control of accuracy, something that is vital in the medical sector.
When the team was happy with the prototypes, our software designed the tool and used ‘Mouldflow’ to determine the best location for gating.
Toolpathing then created the cavities for the moulds using a wide variety of carbide cutting tools on 3 axis CNC machining centres.
Moving from prototyping to production had to be rapid for this one. We sent initial sample parts in nylon 30% glass fibre and Acetal copolymer for inspection and then agreed the run rates of 1100 parts per day for each component.
When production started, a time and motion study identified how to optimise the cycle time so that we could produce all the parts needed in just 72 hours and deliver them in five intervals to support the lineside production at Mercedes.
Now here’s the thing, it took fewer than 100 hours from the initial meeting to production of the first device for evaluation and regulatory approval. This approval was fast tracked so the time from that first meeting to full delivery of all the components was just 14 days.
Just stop and think about how long it takes for you to normally get tooling for injection moulded parts. It was possible because we use software to check the CAD for manufacturability and had a team examine the whole process from prototyping through to manufacture.
We then managed to produce moulds for injection moulding so quickly because we use aluminium instead of steel. You probably know that most suppliers will quote you delivery times of 10 to 12 weeks for steel moulds. In the future If you don’t need hundreds of thousands of parts, then ask whether you need steel moulds. Or perhaps you need a lower run for bridge manufacturing?
The best thing about this whole story must be that these CPAP devices were sent to 250 hospitals across the UK and helped frontline staff provide the best possible care for Covid-19 patients.
This pandemic has been truly terrible, but it has shown how quickly industry and its supply chain can respond when really challenged. I think that manufacturing has learnt some lessons and that product development times will shorten dramatically.
That’s it for this week. I look forward to seeing you again next Friday.
With special thanks to Natalie Constable.