Lightweight polymer pellet

Abstract

A lightweight pellet ( 10 ) is provided having an exterior shell ( 11 ) made of an already-expanded polymer material. Each pellet ( 10 ) has a specific gravity of about 0.01 to about 0.3 and has an average size of about 0.01 mm to about 6 mm. A plurality of the pellets ( 10 ) can be used to make free-flowing materials, liquid carrier compositions, solidified pods, coating layers, and/or masonry units.

1 . A pellet having a specific gravity of about 0.01 to about 0.3 and having an average size of about 0.01 mm to about 6 mm;
 wherein the pellet comprises an exterior shell completely enclosing an interior core; and   wherein the exterior shell is made of an already-expanded thermoplastic material.   
     
     
         2 . A pellet as set forth in  claim 1 , wherein the interior core has a small amount of liquid content. 
     
     
         3 . A pellet as set forth in  claim 1 , wherein the interior core contains an expansion agent. 
     
     
         4 . A pellet as set forth in  claim 3 , wherein the exterior shell is impervious with respect to the liquid content. 
     
     
         5 . A pellet as set forth in  claim 1 , wherein the exterior shell comprises a wall which incorporates the pellet's outer surface. 
     
     
         6 . A pellet as set forth in  claim 1 , wherein the shell comprises a wall and coating surrounding the wall, and wherein the coating incorporates the pellet's outer surface. 
     
     
         7 . A pellet as set forth in  claim 1 , wherein the thickness of the exterior shell is at least 5% of the shell's diameter and/or wherein the thickness of the shell is significantly less than 50% of the shell's diameter. 
     
     
         8 . A free-flowing material comprising a plurality of the pellets set forth in  claim 1 . 
     
     
         9 . A free-flowing material as set forth in  claim 8 , additionally comprising a liquid carrier in which the pellets are dispersed. 
     
     
         10 . A free-flowing material as set forth in  claim 9 , wherein the pellets remain substantially the same size, shape, and specific density in the liquid carrier. 
     
     
         11 . A free-flowing material as set forth in  claim 8 , wherein the pellets are precoated with a binder adapted to solidify the material into a rigid composition. 
     
     
         12 . A free-flowing material as set forth in  claim 11 , wherein the binder is adapted to be cured to solidify the material into a rigid composition. 
     
     
         13 . A pod made by fluidly introducing the free-flowing material of  claim 8  into a cavity and allowing the material to solidify, wherein the volume of material introduced into the cavity is substantially equal to the pod volume. 
     
     
         14 . A coating layer made by applying the free-flowing material of  claim 8  onto a substrate surface and allowing the material to solidify. 
     
     
         15 . A pod comprising a plurality of the pellets set forth in  claim 1 , dispersed in a solidified binder, wherein the pod has volume which remains within about 5% of its installation volume for at least 5 years. 
     
     
         16 . A pod as set forth in  claim 15 , having an R value of at least 2.0 and/or having an STC factor of at least 30. 
     
     
         17 . A coating layer comprising a plurality of the pellets set forth in  claim 1  dispersed in a solid binder. 
     
     
         18 . A masonry unit comprising a plurality of the pellets set forth in  claim 1 , and a hardened cement mixture comprising cement, an aggregate, and/or resin, binder or adhesive systems.