Heat insulating container
A heat-insulating container having a first fiber layer ( 111 ) with a prescribed density and a second fiber layer ( 112 ) which is formed inside the first fiber layer ( 111 ) and has a lower density than the first fiber layer ( 111 ). The first fiber layer ( 111 ) is 0.2 to 1 mm thick, and the second fiber layer ( 112 ) is 0.4 to 3 mm thick, with the total thickness of the first fiber layer ( 111 ) and the second fiber layer ( 112 ) being 0.6 to 4 mm.
1. A heat-insulating container having at least a first fiber layer having a prescribed density which is made mainly of pulp by papermaking and a second fiber layer which is formed inside said first fiber layer and has a lower density than said first fiber layer,
wherein said first fiber layer has a thickness of 0.2 to 1 mm, said second fiber layer has a thickness of 0.4 to 3 mm, the total thickness of said first fiber layer and said second fiber layer is 0.6 to 4 mm, and the density of the body of said container varies in the vertical direction thereof.
2. The heat-insulating container according to claim 1 , wherein said container has a blowing agent layer in place of said second fiber layer.
3. The heat-insulating container according to claim 1 , wherein said total thickness varies in the body of said container in the vertical direction.
4. A heat-insulating container comprising:
at least a first fiber layer with a prescribed density which is made substantially of pulp by papermaking,
a second fiber layer which is formed inside said first fiber layer and made of a material containing a blowing agent and has a lower density than said first fiber layer; and
a third fiber layer which is formed inside said second fiber layer and has a higher density than said second fiber layer, said container having a flange on the periphery of the opening thereof, and said first and said third fiber layers being joined together to form a unitary body at the periphery of said flange.
5. The heat-insulating container according to claim 4 , wherein a mixed layer comprising said pulp and said blowing agent exists between said third fiber layer and said second fiber layer, and said third fiber layer and said second fiber layer are fixed together via said mixed layer.
6. The heat-insulating container according to claim 4 , wherein the density of said third fiber layer is equal to or lower than that of said first fiber layer.
7. The heat-insulating container according to claim 4 , wherein said container has a blowing agent layer in place of said second fiber layer.
8. The heat-insulating container according to claim 4 , wherein the first and third fiber layers are, at the location of the flange, disposed parallel to each other and in contact with each other.
9. The heat-insulating container according to claim 4 , wherein the first and third fiber layers are adhered to each other with an adhesive to form the flange.