Hello all! I want to do a project about recycling 50cm plastic juice bottle and pepsi metal cans.So i was thinking to use a inductive sensor to detect the cans and a capacitive sensor to detect the bottles , but i think that the capacitive sensors will detect my cans too so i have another ideea to use a optical sensor and when the both sensors are sensing the object ,then its metal and when only the optical sensor is sensing the object then its the bottle. But i am searching a sensor that cam detect the plastic .I found that the IR sensors can detect various types of plastics but i dont know whici IR sensor to buy and how to configure it to sense the bottle. Can you help me ?