US 3892622 A
Inlaying a continuous filamentous reinforcement, such as individual filaments or scrim, in nonwoven web material is effected by carrying the filamentous reinforcement in the slurry stream in a headbox to a web forming porous traveling surface and on the forming surface forming the slurry into a fibrous web with the filamentous reinforcement integrally embedded in the web.
Description (OCR text may contain errors)
United States Patent 11 1 Skaugen INLAYING CONTINUOUS FILAMENTOUS REINFORCEMENT IN A NONWOVEN WEB  Inventor: Borgeir Skaugen, Beloit, Wis.
 Assignee: Beloit Corporation, Beloit, Wis.
 Filed: Dec. 5, 1973 211 Appl. No.'. 421,990
OII' 'IIIIlI/IIIIIIIIII IIIIIIIIIIII' I 1 51 July 1, 1975 Primary ExaminerS. Leon Bashore Assistant Examiner-Richard V. Fisher Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson  ABSTRACT lnlaying a continuous filamentous reinforcement, such as individual filaments or scrim, in nonwoven web material is effected by carrying the filamentous reinforcement in the slurry stream in a headbox to a web forming porous traveling surface and on the forming sur' face forming the slurry into a fibrous web with the filamentous reinforcement integrally embedded in the web.
Introduction of the filamentous reinforcement into the slurry in the headbox may be effected through one or more nozzles discharging downstream in the headbox, the filamentous reinforcement being transported through the nozzle in a carrier liquid such as water. The nozzle may have a venturi geometry whereby to assure a pressure drop for positively drawing the filamentous reinforcement from the nozzle into the pressurized slurry stream.
19 Claims, 4 Drawing Figures INLAYING CONTINUOUS FILAMENTOUS REINFORCEMENT IN A NONWOVEN WEB This invention relates to the art of reinforcing nonwoven webs, and is more particularly concerned with inlaying a continuous filamentous reinforcement in such webs.
lnlaying of filamentous reinforcement in the form of individual fibers or as scrim in nonwoven web material such as paper has heretofore generally been effected by lamination, that is, two sheets of desired characteristics have been laminated with the reinforcement therebetween where a reinforcing inlay has been deemed necessary to attain proper strength. This means that the web muust be made on one machine or at least one operating apparatus of a machine and then the laminating is effected away from that particular machine or apparatus portion of a machine. Therefore, prior methods and apparatus have been fairly complex, expensive, cumbersome, of limited application and relatively inefficient.
An important object of the present invention is to overcome the foregoing and other disadvantages, deficiencies, inefficiencies, shortcomings and problems in prior methods and structures and to attain important new and improved results and advantages in the inlay ing of continuous filamentous reinforcement in nonwoven web materials.
Another object of the invention is to provide a new and improved method of and means for high speed production inlaying of filamentous reinforcement in nonwoven webs.
A further object of the invention is to provide a new and improved method of and means for inlaying filamentous reinforcement in nonwoven webs continuously as an integral part of the web-manufacturing process.
Still another object of the invention is to provide a new and improved method of and means for integrally incorporating filamentous reinforcement of diverse selected types, individual filament or scrim, in nonwoven webs coincident with formation of the webs.
Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawing although vaiations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:
FIG. I is a schematic illustration of a web forming apparatus embodying features of and especially adapted for practice of the present invention;
FIG. 2 is a fragmentary sectional elevational view taken substantially along the line "-11 of FIG. 1;
FIG. 3 is an enlarged sectional detail view taken substantially along the line III-III of FIG. 2; and
FIG. 4 is a sectional elevational view similar to FIG. 2 but showing a modification.
By way of a practical example, a continuous high speed web forming apparatus as shown in FIG. 1 includes a pressurized fibrous stock supply inlet 5 leading to a pressure head box 7 extending in an upwardly inclined direction toward a web-forming porous traveling surface such as a fourdrinier wire belt 8 which extends in an upwardly inclined direction in its forming run with its inclined direction being provided to accomodate the upward inclination of the headbox. The forming belt 8 is driven at a suitable speed in the forming direction as indicated by arrows and is supported on suitable rolls including a breast roll 9 and a couch roll 10 and in the vicinity of the couch roll may have suitable means (not shown) for taking offthe formed nonwoven web for further processing including drying and calendering. At its downstream or forming end the headbox has a slice 11 where the stream of stock is driven against the forming belt 8 which in this forming area has associated therewith drainage and suction means comprising an underlying perforated plate 12 on top of a suction box having a suction pump 13 connected thereto and leading at its lower end to a water collection container 14.
According to the present invention, inlaying of continuous filamentous reinforcement 15 in a nonwoven web 17 produced by means of the described apparatus is accomplished by feeding the filamentous reinforcement into the fibrous stock slurry stream in the headbox 7, and carrying the reinforcement 15 in the slurry in the stream to the forming surface 8 where the reinforcement is integrally embedded in the fibrous web formed from the slurry. In one form, the filamentous reinforcement 15 comprises individual filaments, either monofilament or multifiber or twisted fiber types and of any suitable gauge and material adequate for the particular character and finish of the web 17 which may comprise paper, roofing felt, nonwoven fabric, and the like. To this end, the filaments 15 are fed by ejecting each of them through an elongated orifice 18 conveniently extending through a manifold I9 located across the upstream end portion of the headbox 7 and forwardly or in downstream alignment with a header 20 with which the inlet 5 communicates. In the illustrated instance the manifold 19 is provided with a plurality of the orifices 18 in spaced parallel relation to supply a desired number of the reinforcing filaments 15 into the slurry stream. For example, the orifices may be in staggered relation in a plurality of rows across the width of the manifold. Each of the orifices 18 is dimensioned to provide a substantial cross sectional flow area therethrough and to develope therein a substantial velocity of the slurry under pressure from the header 20 with the pressure drop into the main chamber of the headbox 7. This velocity of the slurry through the orifices l8 assures proper distribution of the filaments 15 submerged in the on-flowing slurry stream.
Delivery of the filamentous reinforcement filaments 15 into the orifices 18 is facilitated by conveying the filaments in a liquid carrier through respective conveyor and distributor pipes 21 which extend concentrically through and into the upstream end portions of the respective orifices 18 and terminate in respective discharge nozzles 22 of a preferably generally venturi geometry and located intermediate the ends of the orifices, such as about midway between such ends. Thereby the nozzles 22 discharge into the stream of slurry rushing through the respective orifice 18 with the respective reinforcing filament l5 ejected centrally of the orifice passage into the stream. Efficiency of ejection of the filaments 15 into the orifice stream is improved by having the diameter of the upstream portions of the orifices 18 about the delivery pipes 21 of smaller diameter than the downstream portions of the orifices and with the discharge nozzles 22 located at the juncture of the differential diameter portions of the orifices substantially as shown in FIG. 3.
Fluid carrier such as water is supplied to the conveyor pipes 21 preferably together with the filamentous reinforcement strands or filaments 15. For this purpose, the entry ends of the pipes 21 may, as shown in FIG. 1, be directed upwardly to receive the filaments 15 from suitable supply sources such as spools, reels, spinner heads, extruders, or the like. Communicating with the entry ends of the pipes are suitable means for supplying the liquid carrier such as water, herein shown as comprising a tank 23 with which the entry ends of the pipes communicate and to which a constant head of water is supplied as through a supply pipe 24 under the control of a float operated valve 25. This arrangement has the advantage of simplicity in supplying the liquid carrier to the conveyor pipes 21 with the filaments l5 and of providing a constant pressure head to induce flow of the carrier fluid on through the pipes and the discharge nozzles 22, the system substantially correlating speed of movement of the filaments with the speed of movement of the slurry stream for efficient operation.
Where a filamentous reinforcement in the form of scrim 27 (FIG. 4) is to be inlaid continuously in the nonwoven web, the manner of feeding the scrim into the slurry stream may be substantially the same as described for feeding the filament type of reinforcement, except that the delivery nozzle arrangement must be modified to accomodate the loosely woven material comprising the scrim. For this purpose, a scrim delivery nozzle 22' of suitable width to accomodate the scrim delivers the scrim into a complementary orifice 18' in the manifold 19' mounted in the upstream portion of the headbox 7'. Other features of the system may correspond to those described in connection with FIG. 1.
it will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.
I claim as my invention: 1. A method of inlaying a continuous filamentous reinforcement in a nonwoven web, comprising:
supplying fibrous stock slurry through an elongated orifice into a stream traveling through a headbox to a web-forming porous traveling surface;
feeding filamentous reinforcement through a nozzle discharging downstream within the orifice and thereby into the slurry stream;
carrying the filamentous reinforcement in the slurry stream to the forming surface; and
on the forming surface forming the slurry into a web with the filamentous reinforcement integrally embedded in the web.
2. A method according to claim 1, including effecting a pressure drop at the discharge end of the nozzle within the elongated orifice.
3. A method according to claim 1, comprising conveying the filamentous reinforcement in a fluid carrier to and through the nozzle into the orifice.
4. A method according to claim 3, comprising supplying the filamentous reinforcement and the fluid carrier into conveyor pipe means leading to the nozzle.
5. A method according to claim 1, comprising carrying said filamentous reinforcement in a fluid carrier under pressure into the nozzle for feeding the rein forcement into the slurry stream through the orifice.
6. A method according to claim 1, comprising correlating the velocity of filamentous reinforcement feed ing in the nozzle with the rate of travel of the slurry stream to the web forming surface.
7. A method according to claim 1, comprising feeding the filamentous reinforcement in the form of a plurality of individual filaments through respective nozzles into respective orifices discharging into the slurry stream.
8. A method according to claim 1, comprising feeding the filamentous reinforcement in the form of scrim through a nozzle which is of substantial width into an orifice of complementary width and therefrom into the slurry stream.
9. A method according to claim 1, comprisng supplying the fibrous stock slurry into a header, conducting the slurry from the header through said orifice in a manifold in the headbox, and effecting said feeding of the filamentous reinforcement through said header and then into the nozzle.
10. Apparatus including a headbox, means for sup plying fibrous stock slurry to flow in a stream through the headbox, and a web-forming porous traveling surface receiving the slurry from the headbox, the improvement comprising:
said means for supplying the stock slurry comprising an elongated orifice discharging into the headbox; and
means for feeding filamentous reinforcement comprising a nozzle discharging downstream within said orifice and thereby into the slurry stream so that the reinforcement will be carried in the slurry stream to the forming surface and the filamentous reinforcement will be integrally imbedded in the web.
11. Apparatus according to claim 10, including conveyor pipe means leading to the nozzle, and means for supplying a fluid carrier to the pipe together with the filamentous reinforcement.
12. Apparatus according to claim 10, wherein said feeding means nozzle comprises a venturi nozzlev 13. Apparatus according to claim 10, wherein said feeding means comprise a plurality of nozzles spaced laterally from one another and discharging into respective orifices discharging into said slurry stream at a plurality of points to feed individual filaments into the stream.
14. Apparatus according to claim 10, wherein said feeding means comprise a wide nozzle discharging into a complementary wide orifice to feed the filamentous reinforcement in the form of scrim into the stream.
15. Apparatus according to claim 10, including a header, means for supplying the fibrous stock slurry to the header, a manifold for receiving the slurry from the header and having said orifice providing a passage therethrough into the headbox, said nozzle being directed to feed the filamentous reinforcement into said passage intermediate the length of the orifice.
16. Apparatus according to claim 10, wherein the nozzle means is arranged to convey filamentous reinforcement and a fluid carrier into the orifice.
17. Apparatus according to claim 16, wherein said nozzle means has venturi geometry.
18. Apparatus according to claim 17, including a header having said orifice providing an elongated passage therein, said nozzle means discharging into said orifice means intermediate the length of said passage,
19. Apparatus according to claim 18, including conveyor pipe means in delivering relation to said nozzle means, a carrier fluid tank communicating with the pipe means and through which the filamentous reinforcement is supplied into the pipe means, and means for supplying carrier fluid to the tankv