A method for purifying a contaminated reclaimed polyethylene is provided. The method comprises obtaining the contaminated reclaimed polyethylene, extracting it with a solvent to produce an extracted contaminated reclaimed polyethylene, and then dissolving it in the solvent to produce a first suspension comprising dissolved polyethylene and suspended contaminants. The first suspension is settled to produce a second suspension comprising dissolved polyethylene and suspended remaining contaminants, and the second suspension is purified by contacting it with solid media to produce a third suspension comprising purer polyethylene. Finally, the purer polyethylene is separated from the third suspension and it has virgin-like optical properties.

A method for purifying a contaminated reclaimed HDPE is provided. The method comprises obtaining the contaminated reclaimed HDPE, extracting it with a solvent to produce an extracted contaminated reclaimed HDPE, and then dissolving it in the solvent to produce a first suspension comprising dissolved HDPE and suspended contaminants. The first suspension is settled to produce a second suspension comprising dissolved HDPE and suspended remaining contaminants, and the second suspension is purified by contacting it with solid media to produce a third suspension comprising purer HDPE. Finally, the purer HDPE is separated from the third suspension and it has natural-like optical properties.

A method for purifying a contaminated reclaimed HDPE is provided. The method comprises obtaining the contaminated reclaimed HDPE, extracting it with a solvent to produce an extracted contaminated reclaimed HDPE, and then dissolving it in the solvent to produce a first suspension comprising dissolved HDPE and suspended contaminants. The first suspension is settled to produce a second suspension comprising dissolved HDPE and suspended remaining contaminants, and the second suspension is purified by contacting it with solid media to produce a third suspension comprising purer HDPE. Finally, the purer HDPE is separated from the third suspension and it has natural-like optical properties.

Provided is a method of recycling an additively manufactured object into a reusable thermoplastic polymer, which method in some embodiments may include: (a) providing at least one additively manufactured object produced by stereolithography from a dual cure resin, the object comprising (i) a light polymerized polymer, and (ii) a heat polymerized polymer intermixed with said light polymerized polymer; (b) comminuting the object to produce a particulate material therefrom; (c) contacting the particulate material to a polar, aprotic solvent for a time and at a temperature sufficient to extract the heat polymerized polymer from the particulate material into said solvent, leaving residual particulate material comprising said light polymerized polymer in solid form; (d) separating the residual particulate material from said solvent; and then (e) separating the heat polymerized polymer from said solvent to provide a reusable thermoplastic polymer material in solid form.

Provided is a method of recycling an additively manufactured object into a reusable thermoplastic polymer, which method in some embodiments may include: (a) providing at least one additively manufactured object produced by stereolithography from a dual cure resin, the object comprising (i) a light polymerized polymer, and (ii) a heat polymerized polymer intermixed with said light polymerized polymer; (b) comminuting the object to produce a particulate material therefrom; (c) contacting the particulate material to a polar, aprotic solvent for a time and at a temperature sufficient to extract the heat polymerized polymer from the particulate material into said solvent, leaving residual particulate material comprising said light polymerized polymer in solid form; (d) separating the residual particulate material from said solvent; and then (e) separating the heat polymerized polymer from said solvent to provide a reusable thermoplastic polymer material in solid form.

Described herein are systems and methods for the depolymerization of polyethylene-based plastics. In one embodiment, a method is disclosed that comprises combining a polyethylene-based plastic with a solvent in a reactor to generate a plastic solvent mixture, heating the plastic solvent mixture in the reactor, and fractionating the plastic solvent mixture into a gas phase product, a solid phase product, and a liquid phase product. In another embodiment, a system is disclosed that comprises a solvent, and a reactor configured to receive the polyethylene-based plastic and the solvent and convert the polyethylene-based plastic into a gas phase product, a solid phase product, and a liquid phase product, the reactor being configured to operate at a temperature greater than 275° C. and at a pressure greater than 2 megapascals.

Described herein are systems and methods for the depolymerization of polyethylene-based plastics. In one embodiment, a method is disclosed that comprises combining a polyethylene-based plastic with a solvent in a reactor to generate a plastic solvent mixture, heating the plastic solvent mixture in the reactor, and fractionating the plastic solvent mixture into a gas phase product, a solid phase product, and a liquid phase product. In another embodiment, a system is disclosed that comprises a solvent, and a reactor configured to receive the polyethylene-based plastic and the solvent and convert the polyethylene-based plastic into a gas phase product, a solid phase product, and a liquid phase product, the reactor being configured to operate at a temperature greater than 275° C. and at a pressure greater than 2 megapascals.

The present invention generally relates to a method of reducing contamination from plastics. The resulting purer plastic can be used in demanding applications.

The present invention generally relates to a method of reducing contamination from plastics. The resulting purer plastic can be used in demanding applications.

A method of additive manufacturing is comprised of providing a material comprised of a ethyl cellulose polymer having an ethoxy content of 43% to 52% by mass and a plasticizer. The material is heated and dispensed through a nozzle to form an extrudate deposited on a base. The base, nozzle or combination thereof is moved while dispensing the material so that there is horizontal displacement between the base and nozzle in a predetermined pattern to form an initial layer of the material on the base and successive layers of the material are adhered on the initial layer to form an additive manufactured part by repeating the aforementioned steps. The article formed of the ethyl cellulose polymer may be used in many applications such as those related to the pharmaceutical and food industries.