求助：面板设计

公司最近让我做一款塑胶钣金结合的面板，可是我没有塑胶的经验，让我写需要工时，我连做都没做过，也不知道开模要多长时间，具体怎么做，设计要多长时间……总之是上了烤炉了，各位大虾帮帮忙啊！

suggestions:

Due to different thermal dilatation between metal sheet and plastic sheet we suggest to USE ONLY HIDDEN MECHANICAL CONNECTIONS

i.e.: it’s possible to fix the internal side of plastic sheet on metal front panel with screws and hide them behind the aluminium extruded profile