US3806017A

US3806017A - Apparatus for forwarding filamentary materials

Info

Publication number: US3806017A
Application number: US00374135A
Authority: US
Inventors: D Brethauer
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1973-06-27
Filing date: 1973-06-27
Publication date: 1974-04-23
Anticipated expiration: 1991-04-23

Abstract

A jet device for forwarding textile filamentary materials having a flow restrictor added to its inlet end. The restrictor is a housing having a chamber in communication with the jet inlet at one end and atmosphere at the other. The chamber has a plurality of pairs of flexible blades arranged within to form a labyrinthlike space within the chamber. This arrangement functions to effectively enlarge the yarn passage through the jet permitting passage of yarn defects without excessive loss of air from the jet.

Description

United States Patent [191 Brethauer Apr. 23, 1974 [54] APPARATUS FOR FORWARDING 3,580,445 5/1971 Moore 226/97 FILAMENTARY MATERIALS 3,669,328 6/1972 Castelli 226/97 Primary ExaminerAllen N. Knowles Assistant Examiner-Gene A. Church [5 7] ABSTRACT A jet device for forwarding textile filamentary materials having a flow restrictoradded to its inlet end. The restrictor is a housing having a chamber in cornmuni cation with the jet inlet at one end and atmosphere at the'other. The chamber has a plurality of pairs of flexible blades arranged within to form a labyrinth-like space within the chamber. This arrangement functions to effectively enlarge the yarn passage through the jet permitting passage of yarn defects without excessive loss of air from the jet.

5 Claims, 3 Drawing Figures I/////// /V ///7 ///A APPARATUS FOR FORWARDING FILAMENTARY MATERIALS BACKGROUND OF THE INVENTION This invention relates to pneumatic jet devices for forwarding textile filamentary materials. In particular, it relates to jet devices which exert tension on the filaments by means of a high velocity gas stream and thereby induce motion in the filaments.

The jet device as taught by Cope et al. in US. Pat. No. 3,302,237 has been found in many cases to be eminently satsifactory for forwarding filaments with a minimum of entanglement and bunching. Jets of this design have been particularly advantageous for the production of nonwoven webs from continuous synthetic organic filaments.

Since the cost of the gas employed in the jet, whether it be steam, compressed air or inert gas, may be high, attempts to minimize this cost have been taken. Reducing the size of the passageway through which the filaments pass within the jet device has been tried. In fact, the width of the jet passageway has in some cases been reduced to a size approaching that of the width of the material being forwarded. This, of course, has effectively economized on the consumption of treatment fluid employed in the jet device but has given rise to considerable processing difficulties. For example, yarn drips from a malfunctioning spinneret or yarn plugs comprising an entanglement of a plurality of filaments in a multifilament yarn have resulted in frequent maintenance and production shutdowns for jets having narrow yarn treatment passages. In addition, narrow yarn treatment passages tend to complicate the stringup of yarn through the jet and thus require operating personnel with special skills and the use of particular tools and procedures which add further to production costs and result in the reduction of product yield levels.

Attempts to overcome these disadvantages by the simple procedure of increasing the size of the yarn treatment passage has resulted in prohibitively large increases in gas consumption costs and in additional process complications. For example, the increased flow at the outlet end of the jet has been found to disturb downstream processing characteristics, such as the laydown of fiber on a moving belt. Moreover, the resultant high velocity, high volume gas flow through the jet usually generated unacceptably high levels of noise and as a consequence led to the extra expense of enclosing the jets in soundproof enclosures or of requiring operating personnel nearby to wear ear-protective devices.

SUMMARY OF THE INVENTION This invention provides an improved filament forwarding jet device having inlet and outlet ends connected by a filament passage and wherein a flow restrictor housing is connected to the inlet end of the jet. The housing has an elongated internal chamber which communicates with the inlet of the jet at one end and atmosphere at the other. A plurality of pairs of opposed flexible blades extend inwardly from the walls of the chamber. The number of pairs of blades depends on such variables as air pressure, flow and blade stiffness. In the preferred embodiment, a minimum of three pairs of blades of thickness 0.005 inch were used. The blades are spaced from each other to form a narrow opening aligned with the filament passage of the jet. When a plurality of pairs of flexible blades are used, they form a labyrinth-like space within the chamber with a continuous narrow opening aligned with the central plane of the yarn treatment passage of the jet. The flexible blades are constructed and arranged to be sufficiently stiff to restrict the flow of air through the chamber and into the yarn passage. At the same time, the blades are sufficiently resilient to flex temporarily and thereby allow the passage of drips or plugs whenever they occur in the moving yarn line as it passes through the restrictor on its way to the yarn passage which is made sufficiently large to pass these drips or plugs. This is now possible without excessive loss of air by virtue of the flow restrictor attached to the entrance end thereof. The mouth of the restrictor chamber may be flared outwardly to provide easier stringup. The lower end of this chamber is tapered to gradually reduce the cross section to fit the entrance to the yarn inlet of the jet device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a typical filament forwarding jet device which'h'as appended thereto the flow restrictor of this invention;

FIG. 2 is an end view of the combined device in cross section taken along lines 22 of FIG. 1; and

FIG. 3 is an enlarged cross section of the flow restrictor of this invention viewed in the same direction as that for FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning first to FIGS. 1 and 2, this invention is seen to include a jet device 1 having affixed thereto a flow restrictor 9. Jet device 1 in this preferred embodiment is patterned closely after the type of device disclosed by Cope et al. in US. Pat. No. 3,302,237. The jet of this invention, however, includes a wide slot yarn treatment passage 2 which extends from a slightly constricted yarn inlet end 3 past dual fluid orifices 4, 5 and terminates at a yarn outlet end 6. Pressurized treatment fluid such as compressed air from a source (not shown) is fed to orifices 4, 5 via a manifold 7 and supply port 8.

Affixed to the inlet end 3 ofyarn passage 2 is the flow restrictor device 9 of this invention. This comprises a restrictor body 10 bolted to the jet device 1 as shown in FIG. 3 by means of bolts 20, 20' extending through flange-like portion 10' of the restrictor body 10. An elongated chamber 11 is formed symmetrically about the central plane of body 10. It has a flared portion at its upper end and a tapering portion 11' at its lower end which is shaped to reduce the cross section of the chamber down to that of the inlet end 3 of the yarn passage.

Within body 10 there are disposed a plurality of pairs of flexible spaced blades 12 anchored in recesses in the wall of chamber 11. The unsupported edges of blades 12 extend into chamber 11 toward the central plane thereof in a direction generally perpendicular to the path of yarn passing downward therethrough. Pairs of blades 12 are mounted in opposing walls of chamber 1 l in alignment and'with their inner edges nearly touching. For the preferred embodiment, the separation between these inner edges is maintained between 0.040 and 0.060 inch. The plurality of pairs of blades 12 thus form a constricted set of aligned gaps 13 which functions as a restricted upper yarn opening or passageway.

Each blade 12 is constructed of a thin polymeric sheet material between 0.002 inch and 0.010 inch and preferably 0.005 inch thick selected to be sufficiently stiff to resist movement of air flow into yarn entrance 3 through flow restrictor 9 but to be easily yieldable for passage of enlarged yarn sections such as those caused by plug-like entanglements. As shown in FIG. 3, particularly, the preferred embodiment comprises nine pairs of blades 12 uniformly spaced within chamber 11.

The advantages for this invention are evident from one exemplary application wherein the use of a flow restrictor such as shown in the Figures enabled a jet device to be operable even when the width of the inlet end 3 was increased to a value of 0.125 inch. The noise level and fluid consumption of the jet device with these dimensions and design was found to be no greater than that for jets having inlet openings of 0.020 inch but without the restrictor. For this widened yarn passageway, all yarn line defects were easily conveyed therethrough without risk of plugging the jet yarn passageway.

Many modifications will be apparent to one skilled in the art. For example, the blade elements 12 might be mounted at an angle to the central plane.

What is claimed is:

1. In a filament forwarding jet apparatus having inlet and outlet ends connected by a filament passage, the improvement comprising: a housing connected to the inlet end of the jet, said housing having an elongated internal walled chamber in communication with the inlet of the jet at one end and with outside atmosphere at its other end, said chamber being of the same crosssectional area as the inlet to the jet at said one end and being of enlarged cross-sectional area throughout the remainder of its length; a plurality of pairs of opposed flexible blades extending inwardly from the walls of the enlarged cross-sectional area of said chamber, said blades being spaced from each other to form a narrow opening aligned with the filament passage of the jet.

2. The apparatus as defined in claim 1, there being at least three pairs of flexible blades that form a labyrinthlike space, each pair being aligned to form a continuous opening in line with the passage of the jet.

3. The apparatus as defined in claim 1, each blade being formed of a polymeric sheet.

4. The apparatus as defined in claim 3, each blade being between 0.002 inch and 0.010 inch thick.

5. The apparatus as defined in claim 1, each pair of said blades being positioned in a plane perpendicular to the axis of the jet filament passage.

Claims

1. In a filament forwarding jet apparatus having inlet and outlet ends connected by a filament passage, the improvement comprising: a housing connected to the inlet end of the jet, said housing having an elongated internal walled chamber in communication with the inlet of the jet at one end and with outside atmosphere at its other end, said chamber being of the same cross-sectional area as the inlet to the jet at said one end and being of enlarged cross-sectional area throughout the remainder of its length; a plurality of pairs of opposed flexible blades extending inwardly from the walls of the enlarged crosssectional area of said chamber, said blades being spaced from each other to form a narrow opening aligned with the filament passage of the jet.

2. The apparatus as defined in claim 1, there being at least three pairs of flexible blades that form a labyrinth-like space, each pair being aligned to form a continuous opening in line with the passage of the jet.