Thermal insulation foamed sheet, thermal insulation foamed container and method for producing the same

Abstract

The present invention relates to a thermal insulation foamed sheet whose foaming height can be kept high by increasing a expansion ratio of foaming cells, thermal insulation foamed container using this and method for producing the same. In the thermal insulation foamed sheet according to the present invention, a foaming plane made of a foaming cell group is formed by heating the sheet in which a synthetic resin film is laminated on base paper and foaming the synthetic resin film using moisture contained in the base paper, and at least a part of the foaming plane is vacuum-suctioned so as to increase the foaming height of the foaming cell. Also, there can be made a thermal insulation foamed container having this foaming plane on at least its body section.

1 . A thermal insulation foamed sheet characterized by that a sheet in which a synthetic resin film is laminated on base paper is heated, a foaming plane made of a foamed cell group is formed by foaming the synthetic resin film mainly using moisture contained in the base paper, and the foaming height of the foaming cells is increased by at least a part is vacuum-suctioned in a die whose size is set so that a gap for suctioning a foaming cell is generated between said foaming plane and a suctioning surface provided in the die.  
   
   
       2 . A thermal insulation foamed sheet in  claim 1 , wherein the foamed cell group is made of foaming cells adhering to the base paper.  
   
   
       3 . A thermal insulation foamed sheet in  claim 1 , wherein the foamed cell group is made of the foaming cells adhering to the base paper and the foaming cells separated and floated from the base paper and the adjacent foaming cells stuck together to make the apparent foaming height even.  
   
   
       4 . A thermal insulation foamed sheet in  claim 1 , wherein said foaming plane is formed on a part of the sheet.  
   
   
       5 . A thermal insulation foamed sheet in  claim 1 , wherein a constraint means for constraining the sheet on which a foaming plane is formed at a predetermined position in a die to prevent it from being moved or deformed so that an even suctioning force is applied on the foaming plane at vacuum-suctioning.  
   
   
       6 . A thermal insulation foamed container characterized by that the thermal insulation foamed sheet in  claim 1  is used at least at a body section of the container.  
   
   
       7 . A thermal insulation foamed container having a foaming plane at least at its body section characterized by that a synthetic resin film is laminated on at least one side of base paper with the other side also subjected to lamination, and the body section or the container is heated so as to form a foaming plane made of a foamed cell group by foaming said synthetic resin film mainly using moisture contained in the base paper, and at least a part is vacuum-suctioned in a die whose size is set so that a gap for suctioning a foaming cell is generated between said foaming plane and a suctioning surface provided in the die so as to increase the foaming height of the foaming cell.  
   
   
       8 . A thermal insulation foamed sheet in  claim 7 , wherein the foamed cell group is made of foaming cells adhering to the base paper.  
   
   
       9 . A thermal insulation foamed sheet in  claim 7 , wherein the foamed cell group is made of the foaming cells adhering to the base paper and the foaming cells separated and floated from the base paper, and the adjacent foaming cells stuck together to make the apparent foaming height even.  
   
   
       10 . A thermal insulation foamed container in  claim 7 , wherein said foaming plane is formed on a part of the body section or a part of the container.  
   
   
       11 . A thermal insulation foamed container in  claim 7 , wherein a constraint means for constraining the sheet on which a foaming plane is formed at a predetermined position in a die to prevent it from being moved or deformed so that an even suctioning force is applied on the foaming plane at vacuum-suctioning.  
   
   
       12 . A method for producing a thermal insulation foamed sheet comprised of a step of forming a foaming plane made of a continuous foamed cell group by heating a sheet in which a synthetic resin film is laminated on base paper and by foaming the synthetic resin film mainly using moisture contained in the base paper, and a step of increasing the foaming height of the foaming cell by at least a part is vacuum-suctioned in a die whose size is set so that a said foaming plane and a suctioning surface provided in the die.  
   
   
       13 . A method for producing a thermal insulation foamed sheet in  claim 12 , wherein the foamed cell group is made of foaming cells adhering to the base paper.  
   
   
       14 . A method for producing a thermal insulation foamed sheet in  claim 12 , wherein the foamed cell group is made of the foaming cells adhering to the base paper and the foaming cells separated and floated from the base paper, and the adjacent foaming cells stuck together to make the apparent foaming height even.  
   
   
       15 . A method for producing a thermal insulation foamed sheet in  claim 13 , wherein a step is provided to constrain the sheet in which the foaming plane is formed at a predetermined position in a die to prevent it from being moved or deformed so that an even suctioning force is applied on the foamed surface at vacuum-suctioning.  
   
   
       16 . A method for producing a thermal insulation foamed container having a foaming plane at least on a body section comprised of a step of forming a foaming plane made of a foamed cell group by foaming a synthetic resin film in which the both sides of base paper is laminated mainly using moisture contained in the base paper through heating, and a step of increasing the foaming height of the foaming cell by at least a part is vacuum-suctioned in a die whose size is set so that a gap for suctioning a foaming cell is generated between said foaming plane and a suctioning surface provided in the die.  
   
   
       17 . A method for producing a thermal insulation foamed sheet in  claim 16 , wherein the foamed cell group is made of foaming cells adhering to the base paper.  
   
   
       18 . A method for producing a thermal insulation foamed sheet in  claim 16 , wherein the foamed cell group is made of the foaming cells adhering to the base paper and the foaming cells separated and floated from the base paper, and the adjacent foaming cells stuck together to make the apparent foaming height even.  
   
   
       19 . A method for producing a thermal insulation foamed container in  claim 16 , wherein a step is provided to constrain the sheet in which the foaming plane is formed at a predetermined position in a die to prevent it from being moved or deformed so that an even suctioning force is applied on the foaming plane at vacuum-suctioning.