METHOD AND APPARATUS FOR THE TRANSFER OF A WET-LAID NONWOVEN TEXTILE WEB FROM A PERFORATED CONVEYOR SURFACE TO A SEIVE DRUM SURFACE

• US 3,839,146 A
• Filed: 10/07/1970
• Issued: 10/01/1974
• Est. Priority Date: 10/10/1969
• Status: Expired due to Term

• Current Assignee: Heinz Fleissner
• Original Assignee: Heinz Fleissner
• Inventors: Fleissner, Heinz
• Primary Examiner(s): Bashore, S. Leon
• Assistant Examiner(s): Tushin, Richard H.
• Application Number:
  US05/078,811
• Time in Patent Office: 1,455 Days
• Field of Search: 162/207,358,359,362,117,368,369,370,317,184,185,307,362,116,114,375,306,290 34/115,122 117/119.8
• US Class Current: 162/207
• CPC Class Codes: D04H 1/64 the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
• CPC Class Codes: D04H 1/732 by fluid current, e.g. air-lay
• CPC Class Codes: D04H 1/736 characterised by the apparatus for arranging fibres D04H1/728, D04H1/732 take precedence
• CPC Class Codes: D21F 5/02 Drying on cylinders

Abstract

A fibrous web conveying system for transferring a newly formed web from a wet-laying unit to a seive drum dryer. The wet web is carried on a perforated conveying surface which comes into tangential contact with the curved surface of a perforated seive drum within the dryer, and web transfer is aided by air flowing through the perforated conveying surface into the seive drum by a suction draft. The perforated conveying surface can be a perforated hollow roller or an endless conveying belt such as a forming wire.

Claims

1. A METHOD FOR THE WET-LAY PRODUCTION OF NONWOVEN TEXTILE MATERIALS WHICH COMPRISES UNITING TEXTILE FIBERS INTO A WET WEB ON A WET WEB LAYING UNIT, SAID WEB HAVING A MOISTURE CONTENT OF UP TO ABOUT 300%, CONVEYING SAID WET WEB FROM SAID WEB LAYING UNIT ON AN ENDLESS PERFORATED CONVEYOR MEANS TRANSFERRING THE WET WEB FROM SAID PERFORATED CONVEYOR MEANS TO A SIEVE DRUM DRYING CONTAINING AT LEAST ONE SIEVE DRUM MEANS HAVING A CONVEYING SURFACE SUBJECTED TO A SUCTION DRAFT, SAID WET WEB BEING TRANSFERRED TO THE CONVEYING SURFACE OF A FIRST SIEVE DRUM MEANS DUE TO THE SUCTION DRAFT APPLIED TO SAID SIEVE DRUM MEANS IN SAID DRIER BY POSITIONING ONE END OF THE CONVEYOR MEANS CLOSELY ADJACENT AND TANGENT TO THE CONVEYING SURFACE OF SAID FIRST SIEVE DRUM MEANS AND BY REVERSING THE DIRECTION OF TROVEL OF THE CONVEYOR MEANS ON WHICH SAID WEB IS BEING CONVEYED IMMEDIATELY IN FRONT OF THE CONVEYING SURFACE OF SAID FIRST SIEVE DRUM MEANS, AND DRYING THE WET WEB IN SAID SIEVE DRUM DRYER TO THE DESIRED MOISTURE CONTENT BY CONVEYING SAID WET WEB ON THE CONVEYING SURFACE OF SAID SIEVE DRUM MEANS AND BY DRAWING A HEATED GASEOUS TREATMENT MEDIUM THROUGH THE WEB AND THROUGH SAID CONVEYING SURFACE BY SAID SUCTION DRAFT.

2. The method of claim 1, wherein the heated treatment medium is hot air.

3. The method of claim 1, wherein the conveying surface of the first sieve drum means is travelling in substantially the same direction as the web at the time of transfer.

4. The method of claim 1, wherein the wet web is first predried down to a residual moisture content of between 30 and 80 percent in said sieve drum dryer, the predried web is then treated with heat-settable liquid preparations, and the treated web is finally dried while these preparations are simultaneously heat-set on the web in another sieve drum dryer.

5. The method of claim 4 wherein the predrying and final drying of the web is effected by conveying the web on the surface of at least one sieve drum means subjected to a suction draft and wherein the treatment medium is drawn through the web, alternately from both sides of the web, thereby penetrating the web a plurality of times.

6. The method of claim 4, wherein after final drying, the dry fiber web is embossed between a pair of opposing cooled rollers.

7. The method of claim 4, wherein the final drying is effected at a temperature of about 180*C to 230*C.

8. An apparatus for the wet-lay production of nonwoven textile materials which comprises a wet laying unit, at least one endless perforated conveyor means having a conveying surface for conveying a wet web formed of textile fibers from within said unit to a sieve drum dryer containing at least one sieve drum means having a curved conveying surface subjected to a suction draft for drawing a heated gaseous treatment medium into said sieve drum means, said sieve drum means being rotatably mounted within said dryer, one end of said conveyor means extending into close proximity of and being tangent to the curved conveying surface of a first sieve drum means in the sieve drum dryer, said conveyor means including a reversing roller means positioned at said one end for reversing the direction of travel of said conveying surface immediately in front of the curved conveying surface of said first sieve drum means to effect transfer of said web to said sieve drum means by said suction draft, the curved conveying surface of said first sieve drum means travelling substantially in the same direction as the web during transfer of the web from said conveyor means.

9. The apparatus of claim 8, wherein the sieve drum dryer is a predryer, which is followed by an applicating means and a final dryer containing at least one sieve drum means subjected to a suction draft.

10. The apparatus of claim 9, wherein the final dryer is followed by a squeezing unit consisting of two opposing, cooled squeeze rollers.

11. The apparatus of claim 8, wherein the reversing roller means is a hollow, perforated reversing roller disposed tangent to the side portion of the first sieve drum means, thus facilitating the transfer of the web from the conveyor means to an upward moving curved conveying surface of the first sieve drum means.

12. The apparatus of claim 8, wherein means are provided for mounting said reversing roller means to be swivellable toward and away from the first sieve drum means of the sieve drum dryer.

13. The apparatus of claim 8, wherein the the reversing roller means is arranged adjacent to said sieve drum dryer whereby said reversing roller means is supplied with fresh air from outside of said sieve drum dryer.

14. ThE apparatus of claim 8, wherein said sieve drum dryer includes a housing in which said first sieve drum means is rotatably disposed, said housing having an inlet through which the web enters the sieve drum dryer, and said reversing roller means at the end portion of the endless perforated conveyor means includes a hollow, perforated reversing roller, said reversing roller being positioned in the inlet of said housing whereby fresh air is drawn through said hollow perforated roller towards the first sieve drum means in said sieve drum dryer.

15. The apparatus of claim 14, wherein the hollow, perforated reversing roller contains a blowing element which is pointed in the direction of that portion of the hollow roller from which the web is released from the hollow roller.

16. The apparatus of claim 14, wherein the perforated hollow roller is designed as a reversing roller for an intermediate endless conveyor means which takes the web off a conveyor means of the web web laying unit and transports it to the sieve drum dryer.

17. The apparatus of claim 8, wherein the endless conveyor means includes a belt made of felt.

18. The apparatus of claim 8, wherein the reversing roller means is a hollow, perforated reversing roller disposed tangent to the bottom side portion of the first sieve drum means, thus facilitating the transfer of the web from the conveyor means to a downwardly moving curved conveying surface of the first sieve drum means;

said at least one perforated conveyor means including an endless conveyor means of said wet laying unit on which the wet web is formed and two other endless conveyor means for transporting the web to said sieve drum dryer; and

a heated cylinder positioned between said two other endless conveyor means for contacting said web.

19. The apparatus of claim 8, wherein the at least one endless perforated conveyor means includes an endless perforated conveyor means within said wet laying unit on which the wet web of textile fibers is formed and at least one other endless perforated conveyor means, said other conveyor means transporting said web from the conveyor means of the wet web laying unit to the sieve drum dryer and a suction roller disposed at the point of transfer of the wet web from the conveyor means of the wet laying unit to the other conveyor means.

20. An apparatus for the wet-lay production of nonwoven textile materials which comprises a wet laying unit, at least one endless perforated conveyor means having a conveying surface for conveying a wet web formed of textile fibers from within said unit to a sieve drum dryer containing at least one sieve drum means having a curved conveying surface subjected to a suction draft for drawing a heated gaseous treatment medium into said sieve drum means, said sieve drum means being rotatably mounted within said sieve drum dryer, one end of said conveyor means extending into close proximity to a first sieve drum means in the sieve drum dryer, a perforated transfer drum subjected to a suction draft tangentially disposed between the one end of said endless perforated conveyor means and the first perforated sieve drum of the sieve drum dryer, the curved conveying surface of said first sieve drum means travelling in the same direction as said web at the time of transfer.

21. An apparatus for the wet-lay production of nonwoven textile materials which comprises a wet laying unit, at least one endless perforated conveyor means having a conveying surface for conveying a wet web formed of textile fibers from within said unit to a sieve drum dryer containing at least one sieve drum means having a curved conveying surface subjected to a suction draft for drawing a heated gaseous treatment medium into said sieve drum means, said sieve drum means being rotatably mounted within said dryer, one end of said conveyor means extending into close proximity of and being tangent to the curved conveying surface of a first sieve drum means in the sieve drum layer, said conveyor means inCluding a reversing roller means positioned at said one end for reversing the direction of travel of said conveying surface immediately in front of the curved conveying surface of said first sieve drum means to effect transfer of said web to said sieve drum means by said suction draft, the curved conveying surface of said first sieve drum means travelling substantially in the same direction as the web during transfer of the web from said conveyor means, said at least one perforated conveyor means also including an endless conveyor means of said wet laying unit on which the wet web is formed and two other endless conveyor means for transporting the web to said sieve drum dryer;

and a heated cylinder positioned between said two other endless conveyor means for contacting said web.