publication_number US 2004241437 A1 abstract an insulation material having insulative properties of a synthetic down while have a fir tree structure more similar to natural down and being in a blown form the blowable insulation material is composed of plural units each having a number of filaments that are fused at one end of the unit and are open at an opposite end application_number US 44734603 A description turning now more particularly to the drawings fig2 a shows generally the insulation material of the present invention which is in a blowable form the insulation structure 10 comprises a number of individual filaments 12 joined or fused at one end 14 and open at the opposite end that is the insulation structure 10 comprises a fir tree like or dendritic structure similar to the structure of the natural down fiber shown in fig1 in this connection the insulation structure 10 may have all filaments 12 of equal diameter as shown in fig2 a or alternatively a larger diameter core filament 16 surrounded by a plurality of open filaments 12 of smaller diameter as shown in fig2 b in addition the number and length of the filaments 12 16 may be varied also the insulation structure 10 may have straight filaments as shown in fig2 a and 2b or alternatively crimped filaments not shown the insulation structure 10 may comprise a wide range of thermoplastic materials suitable for the purpose and well known to the skilled artisan although the inclusion of non thermoplastics is also.