Genpak, LLC

Reedy International Corporation

Wrh Technology, LLC

Walter R Harfmann

Michael E Reedy

A method for producing low density polyester foam utilizing low I.V. polyester feedstock includes providing a low intrinsic viscosity raw material. The low intrinsic viscosity raw material includes between 25% to 100% of a post consumer polyester and has an intrinsic viscosity of less than 0.8 dl/g. The intrinsic viscosity of the low intrinsic viscosity raw material is increased via a de-condensation reaction configured to support foaming. The intrinsic viscosity of the low intrinsic viscosity raw material is increased to 1.1 dl/g or greater. A starting formulation is created including the low intrinsic viscosity raw material with the increased intrinsic viscosity. The starting formulation is foamed to create the polyester foam. Wherein, the polyester foam produced has a specific gravity of less than 0.65 g/cc.

Method for production of low density polyester foam and articles made thereof utilizing low I.V. polyester feedstock

An annular die designed to produce polymer foam using only one or more ambient gasses as a blowing agent includes an exiting channel with an exit having a cross-sectional area between about two and about ten times that of a smallest point within the exit channel. The section of the die from the smallest point to the exit is thermally isolated from the rest of the die, and the temperature thereof is independently controlled. In addition, the interior surface of the exit channel is coated with a friction-reducing coating.

Polymeric foam sheet using ambient gas blowing agent via controlled expansion

Processes for producing alkenyl aromatic foams utilizing a cycloaliphatic gas as blowing agent, are described. Also disclosed are alkenyl aromatic foams produced by the process which exhibit increased thermal insulation properties.

Process for producing alkenyl aromatic foams having increased thermal insulation using cycloalkane blowing agent and foams produced thereby

Low-density, high service temperature polymer foam is extruded by heating a crystalline polymer resin above its crystalline melt point to melt the resin, selecting a blowing agent combination, combining the blowing agent combination with the resin to create a mixture, cooling the mixture to a temperature approaching a freezing temperature for the mixture, and extruding the foam through a die. The blowing agent combination is made up of 50 to less than 100 mole percent of a first blowing agent having a boiling temperature at STP of greater than 310&deg; K, and more than 0 to 50 mole percent of a second blowing agent having a boiling temperature at STP of less than 310&deg; K. The blowing agent combination has an equilibrium solubility vapor pressure in the polymer of less than 45 atm at the foaming temperature and greater than or equal to 1 atm at the glass transition temperature.

Method for producing polymer foam using a blowing agent combination

A crystalline polymer resin, such as poly(ethylene terephthalate), is heated to melting. One or more blowing agents is selected wherein at least one of the blowing agents has a boiling point greater than the glass transition temperature for the resin and less than the forming temperature, such as the temperature of the mold used to form the useful article. The blowing agent(s) and resin are combined to create a mixture with a blowing agent concentration sufficient to produce a theoretical sheet foam density of less than 0.4 g/cm,. The mixture is cooled to a temperature approaching the freezing point of the mixture, and then extruded into a substantially uniform closed cell polymer foam sheet of density less than 0.4 g/cm,. The extruded sheet is then cooled by direct contact with a cooling surface at a surface temperature below the glass transition temperature such that the blowing agent(s) condenses and the sheet has a density of greater than 0.4 g/cm,and a sheet crystallinity of less than 15%. An article is then formed from the cooled sheet by applying heat such that the condensed blowing agent(s) vaporizes and the article crystallizes at a density of less than 0.4 g/cm,with a crystallinity of greater than 20%.

System for forming low-density polymer foam article

Process for producing alkenyl aromtic foams utilizing a cycloaliphatic gas as blowing agent, are described. Also disclosed are alkenyl aromatic foams produced by the process which exhibit increased thermal insulation properties.

PET foam is processed into flakes. The flakes are densified in a pellet mill at between about 300.degree. F. and about 350.degree. F. to produce pellets. The pellets are then dried in a desiccant dryer at about 350.degree. F. for about 6 hours, so that the dew point of the pellets reaches about -40.degree. F. The dried pellets have an intrinsic viscosity about equal to virgin PET and a crystallinity greater than 20%. This material can be reused as if it were virgin PET.

Method of recycling polyester foam

Low-density, high service temperature polymer foam is extruded by heating a crystalline polymer resin above its crystalline melt point to melt the resin, selecting a blowing agent combination, combining the blowing agent combination with the resin to create a mixture, cooling the mixture to a temperature approaching a freezing temperature for the mixture, and extruding the foam through a die. The blowing agent combination is made up of 50 to less than 100 mole percent of a first blowing agent having a boiling temperature at STP of greater than 310.degree. K, and more than 0 to 50 mole percent of a second blowing agent having a boiling temperature at STP of less than 310.degree. K. The blowing agent combination has an equilibrium solubility vapor pressure in the polymer of less than 45 atm at the foaming temperature and greater than or equal to 1 atm at the glass transition temperature.

A crystalline polymer resin, such as poly(ethylene terephthalate), is heated to melting. One or more blowing agents is selected wherein at least one of the blowing agents has a boiling point greater than the glass transition temperature for the resin and less than the forming temperature, such as the temperature of the mold used to form the useful article. The blowing agent(s) and resin are combined to create a mixture with a blowing agent concentration sufficient to produce a theoretical sheet foam density of less than 0.4 g/cm.sup.3. The mixture is cooled to a temperature approaching the freezing point of the mixture, and then extruded into a substantially uniform closed cell polymer foam sheet of density less than 0.4 g/cm.sup.3. The extruded sheet is then cooled by direct contact with a cooling surface at a surface temperature below the glass transition temperature such that the blowing agent(s) condenses and the sheet has a density of greater than 0.4 g/cm.sup.3 and a sheet crystallinity of less than 15%. An article is then formed from the cooled sheet by applying heat such that the condensed blowing agent(s) vaporizes and the article crystallizes at a density of less than 0.4 g/cm.sup.3 with a crystallinity of greater than 20%.

Method and system for forming low-density polymer foam article

Low density PET foam is extruded by heating PET resin above the crystalline melt point to melt the resin, combining Heptane as the blowing agent with the PET resin to create a mixture, cooling the mixture to a temperature of less than 538.degree. K., and extruding the foam through a die. The Heptane is about 0.5-5% by weight of the mixture, and preferably about 1-3%.

Method for producing polyester foam

Low density PET foam is extruded by heating PET resin above the crystalline melt point to melt the resin, selecting a blowing agent combination, combining the blowing agent combination with the PET resin to create a mixture, cooling the mixture to a temperature of less than 538.degree. K., and extruding the foam through a die. The blowing agent combination is characterized by about 50 to less than 100 mole percent of a first blowing agent having a boiling temperature at STP of greater than 310.degree. K. The blowing agent combination is further characterized by more than 0 to about 50 mole percent of a second blowing agent having a boiling temperature at STP of less than 310.degree. K. The blowing agent combination has an equilibrium solubility vapor pressure in PET of less than 45 atm at the foaming temperature and greater than or equal to 1 atm at the glass transition temperature.

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Matthews, NC, United States of America

Walter R Harfmann