Method for producing fiber molded body

Abstract

Provided is a fiber molded body which has excellent durability against repeated compression and also has excellent flexibility and a cushioning property. The fiber molded body forms, on a surface of the fiber molded body, the ridges having a compressed and flattened shape in the thickness direction of the fiber molded body; or the fiber molded body forms a continuous curved surface with the fiber layer which forms the ridges and extends from both sides of the ridges in the thickness direction of the fiber molded body, and portions of the fiber layer of mutually adjacent ridges which form ridges and extend in the thickness direction of the fiber molded body come into close contact with each other in the thickness direction of the fiber molded body.

What is claimed is: 
     
         1 . A method for producing a fiber molded body having a structure in which a fiber layer formed by opening a bundle of thermobondable continuous fibers having crimps and extending in one direction is folded in a direction in which the continuous fibers extend so that ridges repeatedly appear on a surface of the fiber layer, the method comprising:
 obtaining a fiber layer by uniformly opening the bundle of continuous fibers extending in one direction by tensioning and relaxing by a tow opening method;   continuously pushing the fiber layer in a box in which the opening area decreases from an inlet of the box toward an outlet of the box, so that the fiber layer is accumulated in the box and folded; and   bonding with each other portions of the fiber layer in direct contact with each other to form the fiber molded body, by performing a heat treatment process on the fiber layer having the folded structure by using a hot-air circulation-type heat treatment apparatus,   wherein a number of crimps of continuous fibers in the fiber molded body is in the range from 5 to 25 peaks/2.54 cm;   wherein the fiber molded body forms, on a surface of the fiber molded body, the ridges having a compressed and flattened shape in a thickness direction of the fiber molded body; or   wherein the fiber molded body forms a continuous curved surface with the fiber layer which forms the ridges and extends from both sides of the ridges in the thickness direction of the fiber molded body, and   portions of the fiber layer of mutually adjacent ridges which form ridges and extend in the thickness direction of the fiber molded body come into direct contact with each other in the thickness direction of the fiber molded body.   
     
     
         2 . The method of  claim 1 , wherein the portions of the fiber layer of the mutually adjacent ridges come into direct contact with each other in the thickness direction of the fiber molded body by bonding through thermal bonding of the thermobondable continuous fibers of the fiber layer. 
     
     
         3 . The method of  claim 2 , wherein at least a part of the thermobondable continuous fibers constituting the fiber layer in direct contact with each other in the thickness direction of the fiber molded body is entangled in the fiber layer of adjacent ridges, and the thermobondable continuous fibers constituting the fiber layer and the entangled thermobondable continuous fibers are bonded to each other in the fiber layer of the ridges by thermal bonding. 
     
     
         4 . The method of  claim 1 , wherein an engraved pattern is additionally formed on the surface having the ridges of the fiber molded body. 
     
     
         5 . The method of  claim 1 , wherein the thermobondable continuous fibers are sheath/core type composite continuous fibers comprising polyester as a core and polyethylene as a sheath. 
     
     
         6 . The method of  claim 1 , wherein a single yarn fineness of the continuous fibers is 0.5-100 dtex. 
     
     
         7 . The method of  claim 1 , wherein a total fineness of the fiber bundle is 10,000-500,000 dtex.