| abstract |
Polymeric foam and polymeric foam products that contain a foamable polymer material, at least one blowing agent, activated carbon, and water are provided. The activated carbon acts as both a water absorbent and carrier for the water. The activated carbon is able to control and increase cell size even in the presence of carbon dioxide, HFCs, and/or infrared attenuating agents. Additionally, the activated carbon permits a desired amount of water to be introduced into the polymer melt. By controlling the amount of activated carbon and its water content during an extrusion process, a broad range of cell sizes can be obtained in the extruded product. In exemplary embodiments, the activated carbon is added to a primary extruder and water is directly injected into a secondary extruder. Alternatively, the activated carbon is compounded with a polymer resin, pre-hydrated by conditioning or steam impregnation, and added to a primary or secondary extruder. |