the apparatus 1 according to the invention has a second device 6 generating the silk thread 7 from the protein rich phase 5 of the solution 3 especially the second device 6 is formed as a roll or a reel actuated by an actuating device which draws the silk thread 7 from a drop which is formed from the protein rich phase 5 of the solution 3 at the outlet 43 of the diffusion unit 4 the roll 6 especially draws the silk thread by means of a tensile force necessary for the protein assembly the actuating device actuating the roll 6 especially has a motor and or a gear box fig2 shows a more preferred exemplary embodiment of the diffusion unit 4 shown in fig1 the inside diameter d of the channel 41 serving for passing the solution 3 is preferably substantially constant the diffusion unit 4 is preferably formed as an exchangeable cartridge so that the diffusion unit 4 can especially be exchanged when it is saturated with the protein poor phase of the solution 3 the diffusion unit 4 especially has a third device by which the protein poor phase of the diffusion unit 4 can be.