Method and apparatus for detecting recyclable items concealed within solid waste

A device for detecting the presence of items made of recyclable materials randomly located and arranged within a target of randomly arranged material having random characteristics by detecting the composition of the items made of recyclable materials, comprising:

• means to excite a target suspected of containing at least one recyclable item with acoustic energy, said acoustic energy causing said randomly located and arranged items made of a recyclable material present within said target of randomly arranged material having random characteristics to resonate and thereby produce resonated acoustic energy;
• means to measure said resonated acoustic energy;
• means to compare said measured resonated acoustic energy with known resonated acoustic energies corresponding to items made of known recyclable materials, thereby detecting composition of the items made of recyclable materials based upon interactions of the materials with the acoustic energy;
• and
• means for indicating a substantial correspondence of said measured resonated acoustic energy from the items made of recyclable materials with at least one of said known resonated acoustic energies, thereby indicating the presence of said items made of recyclable materials.

A method for detecting items made of recyclable materials randomly arranged and located in randomly arranged solid waste having random characteristics, comprising the steps of:

• generating acoustic energy of at least one predetermined wavelength;
• directing said acoustic energy in the direction of solid waste, thereby causing items made of recyclable materials within the solid waste to resonate and thereby produce resonated acoustic energy;
• receiving said resonated acoustic energy with a receiver;
• calculating a signature of said resonated acoustic energy by analyzing said resonated acoustic energy, thereby detecting composition of the items made of recyclable materials based upon interactions of the materials with the acoustic energy;
• and
• comparing said calculated signature with known signatures of items made of recyclable materials;
• and
• indicating when said calculated signature substantially corresponds to at least one of said known signatures, thereby indicating the presence of items made of recyclable materials.