Hi everybody,

I am new here and I would like to start with a problem we are having.

We are building carbon fiber boxes“alveoles”. We have already manufactured some, but the final dimensions are noacceptable, they are 600-700 microns bigger than they should and not straight.At the end some pictures of the results and manufacturing procedure.

200 microns prepreg (Fiber/fabric: Torayca M46J /plain weave, 43% of epoxy E022, Cured ply thickness: 0.180mm) was selected.

We wrap inner moulds “mandrels” andpress them with the outer mould. All wall must be 300microns thick.

We used aluminium for the innermoulds 7075 and for the outers stainless steel 304 (1.4301).

Now the idea is designing a newmould. Attached some pictures. We want to use different material with lowerthermal expansion coefficient. We heard about THYROPLAST 2738 EHT plus,but I couldn’t find a supplier (in Germany).

I read about plastic injectionmoulds. There are many types, with low CTE and hard. My first question is therecommendation for the material. We tighten with many screws, very strong. Themould will be used like 100 times.

The tolerances in the drawings are20microns. And surface finishing Ra 0.1 /N3

I appreciate any inputregarding the design.

Thank you

regards

PS: the pictures are from the mould we've been using so far and the drawing of the future we want to build.