Images depicting items in a waste flow on a conveyor belt are provided to two analysis systems. The first system processes images to decode digital watermark payload data found on certain of the items (e.g., plastic containers). This payload data is used to look up corresponding attribute metadata for the items in a database, such as the type of plastic in each item, and whether the item was used as a food container or not. The second analysis system can be a spectroscopy system that determines the type of plastic in each item by its absorption characteristics. When the two systems conflict in identifying the plastic type, a sorting logic processor applies a rule set to arbitrate the conflict and determine which plastic type is most likely. The item is then sorted into one of several different bins depending on a combination of the final plastic identification, and whether the item was used as a food container or not. A variety of other features and arrangements are also detailed.

A plastic item, such as a beverage bottle, conveys two distinct digital watermarks, encoded using two distinct signaling protocols. A first, printed label watermark conveys a retailing payload, including a Global Trade Item Number (GTIN) used by a point-of-sale scanner in a retail store to identify and price the item when presented for checkout. A second, plastic texture watermark conveys a recycling payload, including data identifying the composition of the plastic. The use of two different signaling protocols assures that a point-of-sale scanner will not spend its limited time and computational resources working to decode the recycling watermark, which lacks the data needed for retail checkout. In some embodiments, a recycling apparatus makes advantageous use of both types of watermarks to identify the plastic composition of the item (e.g., relating GTIN to plastic type using an associated database), thereby increasing the fraction of items that are correctly identified for sorting and recycling. A great number of other features and arrangements are also detailed.

A process for the segregation, sterilization, and purification of recycled plastic medical waste with the subsequent production of plastic products made therefrom is disclosed. Also disclosed is a method for the front-end segregation of recycled plastic medical waste into a polypropylene waste stream and a mixed plastic waste stream. These segregated streams are further purified through a processing method that removes contaminating fibrous, metal and other waste products. Polypropylene and mixed plastic streams isolated using these methods yield a homogenous material that can be blended with other materials for the production of raw plastic or for extrusion to form commercial plastic products. A method for tracking regulated and non-regulated medical waste stream production kinetics and chain of custody from discrete waste disposal sites is also disclosed.

Ferromagnetic items (e.g., tags, bands, labels containing iron/steel powder) are attached to selected non-ferromagnetic apparatus (e.g., plastic bottles, plastic bags) so that a magnetic device can be used to sort out the non-ferromagnetic apparatus to which the ferromagnetic item is attached.

The method of uniquely identifying a product for subsequent recycling Includes marking a surface of the product with a first trace signature being representative of the manufacturer of the product.

A computer-implemented method can be used for controlling sorting of plastic compounds. The method involves providing a computer-based database containing entries on a plurality of markers each identifying a specific plastic compound; receiving scan data from a sample of a plastic compound; identifying a marker in the sample of the plastic compound based on the received scan data and the plurality of markers of the database; and sorting of plastic compounds based on the identified marker of the sample of the plastic compound.

A process for the segregation, sterilization, and purification of recycled plastic medical waste with the subsequent production of plastic products made therefrom is disclosed. Also disclosed is a method for the front-end segregation of recycled plastic medical waste into a polypropylene waste stream and a mixed plastic waste stream. These segregated streams are further purified through a processing method that removes contaminating fibrous, metal and other waste products. Polypropylene and mixed plastic streams isolated using these methods yield a homogenous material that can be blended with other materials for the production of raw plastic or for extrusion to form commercial plastic products. A method for tracking regulated and non-regulated medical waste stream production kinetics and chain of custody from discrete waste disposal sites is also disclosed.

Recycling information is associated with objects through the use of molecular tags. The recycling information may describe the type of material that the object is made from as well as provide instructions for recycling. The molecular tags may be polynucleotides or other types of molecules including inorganic molecules. The molecular tags may be embedded within the object or attached to the surface of the object. At the end of the object's life, the molecular tags are read and the recycling information is used to appropriately recycle the object.

Images depicting items in a waste flow on a conveyor belt are provided to two analysis systems. The first system processes images to decode digital watermark payload data found on certain of the items (e.g., plastic containers). This payload data is used to look up corresponding attribute metadata for the items in a database, such as the type of plastic in each item, and whether the item was used as a food container or not. The second analysis system can be a spectroscopy system that determines the type of plastic in each item by its absorption characteristics. When the two systems conflict in identifying the plastic type, a sorting logic processor applies a rule set to arbitrate the conflict and determine which plastic type is most likely. The item is then sorted into one of several different bins depending on a combination of the final plastic identification, and whether the item was used as a food container or not. A variety of other features and arrangements are also detailed.

A plastic item, such as a beverage bottle, conveys two distinct digital watermarks, encoded using two distinct signaling protocols. A first, printed label watermark conveys a retailing payload, including a Global Trade Item Number (GTIN) used by a point-of-sale scanner in a retail store to identify and price the item when presented for checkout. A second, plastic texture watermark conveys a recycling payload, including data identifying the composition of the plastic. The use of two different signaling protocols assures that a point-of-sale scanner will not spend its limited time and computational resources working to decode the recycling watermark, which lacks the data needed for retail checkout. In some embodiments, a recycling apparatus makes advantageous use of both types of watermarks to identify the plastic composition of the item (e.g., relating GTIN to plastic type using an associated database), thereby increasing the fraction of items that are correctly identified for sorting and recycling. A great number of other features and arrangements are also detailed.