Nonwoven-fabric sheet and process for producing same

Abstract

Provided are a nonwoven-fabric sheet having a high liquid permeation rate and a process for producing the sheet. The nonwoven-fabric sheet comprises two layers, a first layer (4) and a second layer (5), and is characterized in that the first layer (4) has a plurality of ridges (2) and grooves (3) which extend in parallel in the lengthwise direction, that the first layer comprises heat-fusible fibers and the second layer comprises crimped fibers, and that the sheet has an average fiber angle of 70 or less in a cross-section parallel to the lengthwise direction. The nonwoven-fabric sheet can be produced by stacking a web comprising fibers having latent crimping properties and a web comprising heat-fusible fibers, ejecting a fluid from a plurality of nozzles arranged in the width direction, while conveying the stack, to form ridges (2) and grooves (3), heating the stack using a means that reduces resistance against the crimping properties of the fibers having latent crimping properties, thereby crimping the fibers having latent crimping properties, and then fusion-bonding the heat-fusible fibers.

Description

technical field [0001] The present invention relates to a nonwoven fabric sheet having a high liquid transmission rate and a method for producing the same. Background technique [0002] Japanese Patent Application Laid-Open No. 2009-30218 discloses a technology for improving liquid permeability by reducing the permeation resistance by setting the average fiber angle in a cross-section parallel to the width direction to 75 degrees or less in a liquid-permeable nonwoven fabric. sex. In the examples, nonwoven fabrics having an average fiber angle of 67.4 to 74.7 degrees are described. In the method disclosed in Patent Document 1, a web (web) is fixed on a suction drum rotating in the machine direction MD, and protuberances and troughs are formed using nozzle assemblies for air blowing arranged at intervals of a desired size, Thereby, the "average fiber angle" of the raised portion is reduced. [0003] Due to the increase in thread tension due to the increase in speed of the ...

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Problems solved by technology

[0003] Due to the increase in thread tension due to the increase in speed of the non-woven fabric production line in recent years, in order to stabilize the transfer process of the non-woven fabric at all times, the tension in the machine direction (longitudinal direction) is applied to the non-woven fabric, and the web is fixed in the direction On the suction roller rotating in the machine direction, ridges and troughs are formed by air jet nozzle assemblies arranged at intervals of required size. Even if the average fiber angle on the cross-section parallel to the width direction is further reduced even if the air volume is blown to the side along the width direction, a load will be applied in the machine direction by the tensile load generated by the line tension after the thermal bonding process, The sheet is stretched. In this case, the conventional example is formed mainly by core-sheath type composite fibers (thermoplastic resin) through fusion and fixation of fiber intersection points. Therefore, there is no coil-like three-dimensional crimp on the fiber network. , elastic body, so once there is no force to recover from the stretched state, the formed raised portion is deformed in the machine direction, thus, the average fiber angle on the cross section parallel to the longitudinal direction becomes large, and there is a decrease in liquid permeability The problem

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