Slicer that exports vectors or pics for every slice For a large scale project, I need a slicer which gives me the slices as image (BMP or vector). 
I have a 3d model and want to assemble it manually using large printouts on  cardboard. For this I need my 3d model somehow sliced into 2mm layers, get a silhouette of the outline for every layer  and print it in cardboard. Later all cardboard layer will be cutted manually and glued  in the right order.

Does somebody know a slicer, which gives me as output images for every slice?
Or any different idea how to geht my large cardboard 3d model?
Your approach is one of many and you may find that Slic3r will do as you require.

There's a direct reference to generating SVG files (vector) at this link:
http://manual.slic3r.org/advanced/svg-output

You may have to create a printer profile based on irrational figures when compared to conventional 3d printers. Your 2mm "layer height" should be matched in the printer settings to an appropriate nozzle diameter for the desired result.

You may find also that Simplify3d will create such files, but it's not a free program.

An alternative to 3d printer slicing software would be to use OpenSCAD to import your model (or create it directly in code) and use the Projection command to generate the individual layers. I've done this and found it works well, but the process to learning the necessary code was time consuming, as I'm not a programmer.

You would also want to incorporate some form of registration in your model, cylindrical holes or external tabs to enable you to properly align each cardboard layer.

If you have a makerspace nearby or know someone with a suitably sized laser cutter, you may also save some labor cutting each panel, as the laser will accept the vector files easily.