METHOD FOR PRODUCING A WET-LAID NONWOVEN FABRIC

• US 20160355961A1
• Filed: 08/23/2016
• Published: 12/08/2016
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: Hokuetsu Corporation
• Original Assignee: Hokuetsu Kishu Paper Company Limited
• Inventors: Sakadume, Nobuyuki, Soyama, Toshihiko, Nemoto, Junji
• Granted Patent: US 10,443,167 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 69/105 Support pretreatment
• CPC Class Codes: D04H 1/04 from fleeces or layers composed of fibres having existing or potential cohesive properties, e.g. natural fibres, prestretched or fibrillated artificial fibres felting apparatus D04H17/00
• CPC Class Codes: D04H 1/26 Wood pulp
• CPC Class Codes: D04H 1/4218 Glass fibres
• CPC Class Codes: D04H 1/5412 sheath-core
• CPC Class Codes: D04H 1/55 Polyesters
• CPC Class Codes: D04H 1/732 by fluid current, e.g. air-lay
• CPC Class Codes: D21H 13/10 Organic non-cellulose fibres
• CPC Class Codes: D21H 13/24 Polyesters
• CPC Class Codes: D21H 13/40 vitreous, e.g. mineral wool, glass fibres
• CPC Class Codes: D21H 17/53 Polyethers; Polyesters
• CPC Class Codes: D21H 17/67 Water-insoluble compounds, e.g. fillers, pigments
• CPC Class Codes: D21H 25/04 Physical treatment, e.g. heating, irradiating D21H25/18 takes precedence; dryer section of machines for making continuous webs of paper D21F5/00
• CPC Class Codes: Y10T 442/60 Nonwoven fabric [i.e., nonwoven strand or fiber material]

Abstract

A method for producing a wet-laid nonwoven fabric for a semipermeable membrane supporting body, the method comprising: performing papermaking according to a wet papermaking method by using a fiber slurry containing a synthetic fiber as a main constituent fiber; drying the fiber slurry; subsequently subjecting the dried sheet to hot press processing two times by using a heat calender apparatus, wherein the hot press process temperature in the second treatments is adjusted to be higher by 10° C. or more than the hot press processing temperature in the first treatment, while treating the dried sheet by using a hard nip heat calender apparatus equipped with a combination of a metal roll and a metal roll for at least one time of the hot press processing; and thereby obtaining a wet-laid nonwoven fabric for a semipermeable membrane supporting body.

Claims

1. A method for producing a wet-laid nonwoven fabric for a semipermeable membrane supporting body, the method comprising:

performing papermaking according to a wet papermaking method by using a fiber slurry containing a synthetic fiber as a main constituent fiber;

drying the fiber slurry;

subsequently subjecting the dried sheet to hot press processing two times by using a heat calender apparatus, wherein the hot press process temperature in the second treatments is adjusted to be higher by 10°

C. or more than the hot press processing temperature in the first treatment, while treating the dried sheet by using a hard nip heat calender apparatus equipped with a combination of a metal roll and a metal roll for at least one time of the hot press processing; and

thereby obtaining a wet-laid nonwoven fabric for a semipermeable membrane supporting body.

2. The method for producing a wet-laid nonwoven fabric for a semipermeable membrane supporting body according to claim 1, wherein the hot press processing that is carried out two times repeatedly uses the same hot pressing apparatus.

3. The method for producing a wet-laid nonwoven fabric for a semipermeable membrane supporting body according to claim 1, wherein the hot press processing that is carried out two times continuously performs the treatment by arranging plural hot pressing apparatuses for the treatment.