Study on the possibilities of detecting recyclable waste using the dielectric properties of materials

The present paper is presenting a study on the possibilities of sorting recycling wastes by using the dielectric properties of the materials they are realized with the purpose of using for an automatic sorting system. Daily we produce a lot of waste coming from our food, drinks, cosmetics, goods, etc. A part of the packages are using the same material, but other are using various combinations of materials, stacked in layers or side by side pieces. Usual recycling packages contain plastic, paper, glass, metal. These materials have different dielectric properties, different textures and different specific weight. The toughest problem is to separate paper and plastic, due to their similar weight and dielectric properties. The present study presents some measurements of various recycling packages on their electric permittivity while being tested as dielectric in a capacitive sensor. Results of the measurements and discussions are presented in the paper together with some useful conclusions.