Sprayed Carbon Fibre

As mentioned in previous posts, Light Black Design  have been working closely with Bentley Motors in the UK, to help them develop a possible process to produce components for future cars within the VW Group.

Key to the engineering of these parts are the use of PUR for the matrix and combining this with a process developed by Bentley Motors called DCFP (Directed Carbon Fibre Preforming).

Key to the potential success of this process is the ability to "spray" chopped carbon fibres (approx 100mm long) onto the mould or part surface whilst still keeping a high degree of alignment of the fibres. This effectively gives you a composite panels with approx 80% of the properties of a Uni-directional tape, but with a fraction of the labour and material costs.

Whilst this is still being developed by Bentley for their automotive products, they are very keen to look at other possible applications, such as marine. I have spoken to them about several possible uses, and I feel that this would be perfect for monolithic parts such as RIBS and tenders. Here, the use of carbon is usually restricted due to material and labour costs, but with this process both of these will be reduced (the labour could even be removed if robots are used). And when every 10% you save in vehicle weight (be it boats or cars) you can save 7% of the fuel. And when you consider the fact that fuel is costing around £1.80 per litre on the rivers now, the potential saving in running costs cannot be ignored.

If any further details are required or if you may have a possible application for this process, then please contact us at any time at Info@LightBlackDesign.com

some lightweight, low cost composite panels

Following on from the forum Dan sat on at the Yacht Racing Design & Technology Symposium in December 2010 www.yrdts.com, here are some of the details of the lightweight, cored and most importantly, cheap, high performance composite panels that were showed at the conference.

This process is one that was developed specifically for the automotive markets, and is traditionally used for rear parcel shelves and boot floors.

During a previous high volume, low-cost car program Dan worked closely with Bayer to develop the process and materials so that we could produce extremely complex 3D parts, that could be used to form the main panels of the chassis. Whilst we cannot obviously show these panels here, we have some small sample sections that will give you an idea of the type of geometry possible.





The process uses Polyurethane as the matrix (rather than the traditional Epoxies and Polyesters usually used in such products). This has an extremely fast cure profile and can be cured in about 90 seconds if required. In fact, from dry cloth on a roll to a fully cured, net edge part ready to be bonded in the chassis was just over 2 minutes... Where these high volumes are needed (up to about 300,000 parts per year) robots are always used to spray the PUR and can also be used to spray additional Chopped fibres into areas that require additional local reinforcements. Dan worked very closely with a company called Hennecke in Germany www.hennecke.com to ensure that all the possible avenues were explored to produce the most efficient (cost and performance) parts.

Whilst these throughput times are perhaps not appropriate for most marine applications, they may allow the designers to produce extremely lightweight, low cost panels such as doors, floorboards. Where a boat manufacturer may perhaps be producing a reasonable boats in a range, if every boat had the same size doors, and every boat has say 3 doors, then the volumes very quickly reach a number that is ideal for this type of process. In fact, on some super yachts, which can have 150m2 of floorboards which are traditionally made from 25mm ply wood, the weight saving could be over 5kg per m2 (i.e 50% of the baseline boards)

If any further details are required or if you may have a possible application for this process, then please contact us at any time at Info@LightBlackDesign.com