Today we made the first prototype for a rear floor panel for a bus. It is quite a big part. The mould was so big it didn’t fit our milling machine, so we had to make it in two pieces.

It is a relatively complex part as well, a sandwich construction with internal sound-dampening material and built-in stringers. It is around 2,5 m wide and 1,5 m long and contains around 20 kg of fiberglass and 30 kg of resin.

We chose vacuum infusion as the production process for this prototype. This process can reach a much higher fiber volume fraction then e.g. hand lay-up or vacuum bagging, thus giving much better laminate properties.

Below is a picture of the infusion process. The injection strategy was a real challenge due to the geometry of the part. I made several small test pieces beforehand to check several aspects of the process before committing to the big product.

In the end the infusion was successful. It took about an hour to fill completely.