Powders comprising solid waste materials

A method of making a powder composition, the method comprising:

• heating, in a process vessel, a solid waste composition in a negative pressure environment, the solid waste composition comprising:
• mixed plastics in an amount of about 2 wt. % to about 60 wt. % of the solid waste composition;
• and
• organic materials;
• melting, in the process vessel, at least a portion of the mixed plastics of the solid waste composition;
• combining a polymer with the solid waste composition to form a composite resin, wherein a total amount of plastics in the composite resin is greater than 65 wt. %, wherein the composite resin has a tensile strength of about 40 MPa to about 150 MPa;
• cooling the composite resin;
• and
• reducing the cooled composite resin to yield a plurality of particles having an average maximum dimension of about 100 μm to about 1600 μm.