Image Number 3 for United States Patent #5213867.
The use of hollow tetrahedral units as cushioning loose-fill is described. The loose-fill tetrahedra can be made from recycled material such as paper waste by the method of the invention. The loose-fill tetrahedra do not fill the entire space surrounding a packed article, but do support each other during shipping and handling. Apparatus for forming the tetrahedra is described.