we have a part which is 220mm long x 100mm wide, it incorporates 2 living hinges along the 220mm length, the part has varying thicknesses, from 1mm thick to 3mm.

problem, we have some depression in the thicker areas and the length is out by 2mm, not shorter though longer, the width of the part is perfect.

the living hinges are ok though a little stiff, hinge thickness is 250um.

material we have used is a polypropylene, it is a bit to rigid, we have changed the mould following suggestions which is working

can anyone make some suggestion on the best Polymer mix to use,

I have read many articles about mixing PE with PP etc.

Michael

PS or supplier that can give us the required material spec