US 3460731 A
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s- 1969 IH. MCCARDELL TROTH, JR 3,460,731
FILAMENT DEFLECTING APPARATUS Filed July 7. 1967 2 sheets sheet 1 INVENT OR may IcCARDELL mm. JR.
ATTORNEY Aug. 12, 1969 H. MCCARD'ELL. TROTH. JR 3,460,73
FILAMBNT DEFLECTING APPARATUS Filed July 7, 1967 2 Sheets-Sheet 2 BY W fla/uii ATTORNEY United States Patent Office 3,460,731 Patented Aug. 12, 1969 US. Cl. 226-97 Claims ABSTRACT OF THE DISCLOSURE An appartus for deflecting filaments emerging from the outlet of a forwarding jet. A housing attached to the outlet end of the jet is periodically supplied with pressurized fluid which discharges onto the filament stream emerging from the jet.
BACKGROUND OF THE INVENTION This invention relates to modified filament forwarding jet devices and in particular to filament forwarding jet devices suitable for controlling the direction of the jet output by periodic deflection with secondary fluid streams.
Jet devices have been used in the textile industry for many years to effect drawing, texturing, stripping, annealing, crimping, bulking, interlacing, etc. of synthetic yarns. These devices usually have had round cross-sections but recently jet devices with rectangular or slot shaped crosssections have been developed. Slot jets are particularly useful when used to strip filaments from draw rolls since they conform closely to the shape of the ribbon of filaments coming off the draw roll.
A recently developed process for preparing continuous filament nonwoven fabrics is described in British Patent 932,482. In this process an electrostatically charged multifilament strand of continuous filaments is forwarded by means of a jet device toward a web laydown zone. As the tension on the filaments is released at the exit of the jet device the filaments separate due to the repelling effect of the electrostatic charge on each of the filaments and while thus separated, are collected as a nonwoven web. When draw rolls are used in the above-described process, it is preferred that the filament forwarding jet be of the slot jet type such as that described in Cope et al., US. 3,302,237. The Cope et al. jet is especially useful in the above-described process since its design maintains the filaments uniformly spread across the filament passageway and avoids filament entanglement and bunching. Nonwoven webs produced according to the above-described process contain filaments which are disposed in a random loopy configuration. When bonded, non-woven fabrics with physical properties independent of direction are obtained.
It is sometimes desirable to control the direction of output of a slot jet device during preparation of a continuous filament nonwoven web. One reason for controlling the direction of the jet output is to provide for more uniform distribution of fibers across a laydown receiver. Another reason for controlling the direction of the jet output is to introduce fiber directionality into the non woven web. Fiber directionality is especially useful in nonwoven fabrics to be used as backing for tufted carpets where resistance to stretch in the machine direction and resistance to neclodown in the cross machine direction after tufting are important.
Uniform control of slot jet output is a necessity during preparation of nonwoven webs. When controlled in an irregular or non-uniform manner, the output of filament forwarding slot jets provides nonwoven webs of nonuniform fabric weight and imperfect fiber alignment when such alignment is desired. It is also desirable to control the output of filament forwarding slot jets used in the preparation of nonwoven webs in such a manner so as to minimize fiber entanglement and bunching.
Deflection of fiber containing fluid streams with secondary fluid streams or mechanical deflectors as known in the art have the diadvantage of promoting filament entanglement and bunching.
SUMMARY OF THE INVENTION The principal objective of this invention is to provide an apparatus for controlling the direction of the output of a filament forwarding slot jet which minimizes filament entanglement and bunching.
This objective is accomplished by providing a housing atttached to the outlet end of a filament forwarding jet. The housing defines a chamber with a discharge slot opening transversely to and adjacent the outlet end of the jet. A source of pulsating pressurized fluid is connected to the chamber and is discharged from the slot for deflecting the filaments emerging from the jet. The slot has a Width of from between .005 inch (.012 cm.) and .080 inch (.203 cm.) and presents a fluid discharge angle of from about 60 to with the axis of the passage through the jet.
BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a schematic isometric view of the modified jet of this invention showing its use in the production of a nonwoven fabric.
FIG. 2 is a cross-sectional end view of the modified jet of this invention.
FIG. 3 is a bottom view of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a ribbon of electrostatically charged continuous filament fibers 10 are forwarded by means of slot jet 12 through a diffuser 36 toward a flexible pervious belt 14, covering a suction means (not shown). As the tension on the filaments is released at the outlet end 16 of the diffuser 36, the filaments are deflected alternately by opposed air streams issuing from slots 18, 20 formed by the end 16 of the diffuser 36 and housings 22, 24 attached to the opposite longitudinal sides of the outlet end 16 of diffuser 36. Chambers 26, 28 defined by housings 22, 24 respectively, are connected to a rotary valve 30 supplied with compressed air at inlet 31 by means of conduits 32, 34.
Referring to FIGS. 2 and 3, slot jet 12 includes an entrance slot 13 projecting into etfuser throat 15 and a generally rectangular filament passage 17. Plenum 19 is supplied with pressurized fluid through ports 21, 23. A diffuser section 36 is attached to the outlet end 38 of jet 12 and defines a filament passage 40 of rectangular crosssection in alignment with passage 17 of the jet. The jet shown schematically in FIG. 2 is similar to the slot jets described in Cope et al. US. 3,302,237 modified with the diffuser section 36 attached to the outlet end of the jet. The end 39- of the diffuser 36 converges toward filament passage 40 while housing 24 is formed to present an interior surface 41 complimental to and spaced from end 39 thus forming slot 18 'which is disposed toward and runs lengthwise of the passage 40. Slot 20 is formed in the same fashion and is defined by complemental surfaces 37, 43.
In operation, pressurized fluid, e.g. compressed air is supplied to rotary valve 30 which is rotated at a constant speed and alternately connects conduits 32, 34 to the source of compressed air. The resulting pulses of air are fed to chambers 26, 28 where they discharge from slots 18, 20 at an angle 6, and impinge against the ribbon of filaments 10 alternately deflecting them in a uniform pattern.
For maximum efliciency the deflection slots 18, 20 should be arranged so that the deflecting streams impinge on the fiber stream issuing from outlet 40 of the diffuser at an angle approaching 90. On balance, the angle should be sufficiently less to avoid any coanda effect that might be caused by the configuration of housing 22 below the diffuser outlet which would tend to hold the filaments in the fully deflected position. Although angles 6 of from 60 to 90 are operable, a useful compromise is to use an angle 9 of 70. At this angle any aerodynamic effects caused by the shape of the bottom part of the housing 22 are minimized while still maintaining reasonable efficiency in the amount of deflection air consumed. The deflection slots 18, 20 should be sized to achieve the desired deflection at moderate chamber pressure, e.g., 1 to psi The preferred slot width is from .015 to .020 inch (.038 to .050 cm.) although slot widths of from about .005 to .080 inch (.012 to .202 cm.) are operable. The length of the chambers 26, 28 and slots 18, 20 should correspond to the lengthwise dimension of the diffuser outlet 40. The exit gap A (FIGS. 2, 3) between the outlet end of the diffuser and housing 22 is preferably between .05 to .50 inch (.12 to 1.2 cm.).
While it is preferred that the deflection housings 22, 24 be attached to a difluser section which is in turn attached to the outlet of a slot jet it is not necessary to do so and the deflection housing may be attached directly to the outlet end of a slot jet as disclosed by Cope et al. without a diffuser. Of course it should be understood that the outlet end of the Cope et al. jet would be modified to converge toward the passage to form in cooperation with housings 22, 24, the angularly disposed slots. It is not necessary that the deflection device of this invention be positioned on both sides of the jet or difluser outlet. Control of the jet or diffuser output can be obtained through the use of a single housing 22 on one side of the jet or diffuser. It is apparent that many changes and modifications may be made to the disclosed apparatus without departing from the spirit of the present invention which is intended to be limited only by the scope of the appended claims.
What is claimed is:
1. In a filament forwarding apparatus including a jet having inlet and outlet ends connected by a filament passage of generally rectangular cross-section, a device for transversely deflecting filaments emerging from the passage at said outlet end, said device comprising:
(a) a housing attached to the jet adjacent its outlet end and in cooperation therewith defining a chamber with a discharge slot disposed toward the passage at said outlet end;
(b) a source of pressurized fluid; and
(c) means connected between said source and said chamber for supplying pulses of pressurized fluid to said chamber, said slot being disposed at an angle of from about to 90 with the axis of the filament passage and running lengthwise thereof.
2. The apparatus of claim 1 wherein the width of said slot is between about .005 and .080 inch.
3. The apparatus of claim 1 wherein the outlet end of said jet converges toward said passage, said housing presenting a surface spaced from and complemental to the converging end of the jet.
4. In a filament forwarding apparatus including a jet and a rectangular elongated diffuser each defining an inlet, a passage of generally rectangular cross-section and an outlet, the diffuser being mounted to the outlet end of the jet their passages being in axial alignment, a device for alternately deflecting filaments emerging from the outlet of the diffuser, said device comprising:
(a) a pair of opposed housings mounted to the diffuser adjacent its outlet end, said housings in cooperation with diffuser defining opposed chambers with opposed discharge slots disposed toward the passage at the outlet end of the diffuser said slots running longitudinally of said passage;
(b) a source of pressurized fluid; and
(c) means connected between said source and said chambers for supplying alternating pulses of pressurized fluid to said chambers, said slots being disposed at an angle of about with the axis of said passage, and having a width of between .005 and .080 inch.
5. The apparatus of claim 4 wherein the outlet end of the diffuser converges toward said passage, said housings presenting complemental surfaces spaced from the converging ends of the diffuser.
References Cited UNITED STATES PATENTS 2,859,506 11/1958 Slayter 28l 2,994,938 8/1961 Lovcland et al. 281.4 3,281,913 11/1966 Morehead et al. 2821 3,317,296 5/1967 Irwin et al. 28-1.4 X 3,346,682 10/1967 Thomson 281.4 X 3,357,074 12/1967 Allman et al. 231.4
ALLEN N. KNOWLES, Primary Examiner