US3836346A

US3836346A - Apparatus for producing fibrous material

Info

Publication number: US3836346A
Application number: US00389094A
Authority: US
Inventors: C Stalego
Original assignee: Owens Corning Fiberglas Corp
Current assignee: Owens Corning
Priority date: 1973-08-17
Filing date: 1973-08-17
Publication date: 1974-09-17
Anticipated expiration: 1991-09-17

Abstract

Apparatus for producing filaments from heat-softened filament forming material comprising a container for holding heat-softened filament forming material, two rows of orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments and means for attenuating the streams into filaments that tends to cause movement of air across each of the rows towards the other during attenuation; the orificed projections in each of the rows have thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation.

Description

States Patent 91 [111 3,836,346 Stalego Sept. 17, 1974 APPARATUS FOR PRODUCING FIIBROUS MATERHAL Charles J. Stalego, Newark, Ohio Owens-Corning Fiberglas Corporation, Toledo, Ohio Filed: Aug. 17, 1973 Appl. No.: 389,094

Inventor:

Assignee:

US. Cl 65/1, 65/16, 425/72 Int. Cl C031) 37/02 Field of Search 65/1, 5, 16; 425/72 References Cited UNITED STATES PATENTS Primary Examiner-Robert L. Lindsay, Jr. Attorney, Agent, or Firm-Carl G. Staelin; John W. Overman; Ronald C. Hudgens [57] ABSTRACT Apparatus for producing filaments from heat-softened filament forming material comprising a container for holding heat-softened filament forming material, two rows of orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments and means for attenuating the streams into filaments that tends to cause movement of air across each of the rows towards the other during attenuation; the orificed projections in each of the rows have thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation.

20 Claims, 17 Drawing Figures PAIENIEDSEP 1 mm sum 1 OF 3 APPARATUS FOR PRODUCING FIBROIUS MATERIAL BACKGROUND OF THE INVENTION Improved platinum alloy stream emitting bushings or feeders used in producing glass filaments have been pursued over the years. This is true for feeders used together with blowers to produce glass filaments.

There has been widespread successful commercial use of blowers to produce glass filaments from molten glass streams emitted from orificed projections on the bottom wall of feeders. The blower releases high energy blasts of steam, compressed air, or other gaseous blowing media under pressure that engage the molten glass streams and attenuate them into filaments.

Blast attenuation of streams by blowers produces fine, soft and long glass filaments (normally in the range of from I to feet long) that are used in a variety of mat, filter and textile type products. Over the years demand has grown for products made from blast attenuated glass filaments.

During operation the blasts from blowers induce detrimental high energy air flow between the tops of the blowers and their associated feeders. As air is drawn into the entrance opening of the blowers, air rushes across orificed projections on the bottom wall of the feeders. The induced high velocity air flow reduces the production life of feeders by eroding the orificed projections and carrying foreign matter into the filament forming regions.

Some of the foreign matter is pernicious to platinum and platinum alloys of feeders at the elevated temperatures used in forming glass filaments. So feeder life is reduced. For example, the heat intensity of the feeders changes most foreign matter to carbon. And carbon tends to make platinum and platinum alloys brittle. Cracking and spalling of these alloys often occurs.

Erosion from the high energy induced air flow is the primary problem reducing feeder life. Over a short time metal at the ends of the orificed projections can be severly eroded. So the effective length of these projections is reduced. Consequently, less viscous and higher temperature molten glass is emitted from the projections; this more fluid molten glass tends to flow to the exterior surface of the bottom wall and flood some of the projections. Filament production is disturbed. In extreme cases filament production can be interrupted.

A feeder promoting flooding because of erosion must be replaced.

Attempts have been made to overcome the problem of erosion from induced air flow in the space between feeder and blower. For example, there have been efforts to thicken the walls of the orificed projections to provide longer bushing life. But there is only limited space available between projections without unduly expanding feeder size. And this space does not allow enough added wall thickness to significantly prolong the life of the orificed projections (feeders). Also, attempts have been made to develop alloys that have improved resistance to chemical attack at elevated temperatures. There has been only limited success since most ingredients providing improved resistance to chemical attack, such as iridium and rhodium, aggravate volatization of alloys at high glass filament forming temperatures. Also, these types of ingredients tend to make platinum alloys too hard and too brittle for easy feeder construction.

SUMMARY OF THE INVENTION An object of the invention is improved apparatus for production of filaments from heat-softened filament forming material.

Another object of the invention is improved apparatus for production of blast attenuated glass filaments from molten glass streams that provides longer production life for feeders supplying the molten glass streams.

These and other objects are attained by apparatus for producing filaments from heat-softened filament forming material comprising means for containing the heatsoftened filament forming material including a wall and a row of orificed projections extending from the wall for emitting streams of the heat-softened material and means for attenuating the streams into filaments that tends to cause movement of air across the row during attenuation, the orificed projections having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation.

Other objects and advantages will become more apparent as the invention is explained with reference made to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of a blower attenuated glass filament forming operation according to the principles of the invention used to produce glass filament mat.

FIG. 2 is a front elevation view taken along the lines 2--2 in FIG. 11.

FIG. 3 is an enlarged end elevation view in section of the feeder and blower shown in FIGS. 1 and 2.

FIG. 4 is an enlarged plan view of the bottom of the feeder taken along the line 44 shown in FIG. 3.

FIG. 5 is a still further enlarged plan view of one of the orificed projections on the bottom wall.

FIG. 6 is an enlarged side elevation view of a portion of the orificed projection and bottom wall of the feeder taken along the line 6-6 shown in FIG. 4.

FIG. 7 is an enlarged front elevation view of a portion of another feeder and blower combination according to the principles of the invention.

FIG. 8 is an enlarged side elevation view, partially in section, of a portion of the feeder shown in FIG. 7. The view is similar to the showing of the feeder portion illustrated in FIG. 6.

FIG. 9 is a plan view of a portion of still another feeder bottom and orificed projection grouping according to the principles of the invention.

FIG. It) is a plan view of a differently shaped orificed projection.

FIG. 11 is a plan view of another differently shaped orificed projection.

FIG. 12 is a plan view of yet another orificed projection.

FIG. 13 is a plan view of still another orificed projectron.

FIG. 14 is a plan view of yet still another orificed projection.

FIG. 15 is a side elevation view of a portion of another feeder according to the principles of the invention.

FIG. 16 is a plan view of a portion of the feeder shown in FIG. 15.

FIG. 17 is a plan view of a portion of another grouping of orificed projections on the bottom wall of another feeder according to the principles of the inventron.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus of the invention are particularly valuable in processes that form filaments from heat-softened filament forming mineral material such as molten glass. Yet method and apparatus according to the principles of the invention are also useful in processes forming filaments from other heat-softenable filament forming materials such as nylon and polyester. Thus, the disclosed glass filament forming and mat making operation is only an example to explain the operation of the invention. The invention has wider application to filament forming operations generally.

FIGS. 1 and 2 show a mat making process using a vertical glass filament forming operation embodying the principles of the invention. The apparatus uses a container or feeder 10, conventionally made of platinum or an alloy of platinum, supplying two parallel rows of closely spaced molten glass streams 12 that are attenuated into glass filaments 14.

The container or feeder holds a body of molten glass. The feeder 10 can receive a continuing supply of molten glass by several known ways. For example, a forehearth can supply molten glass to the feeder 10 from a furnace heating batch mineral material to molten glass. Also, a melter associated with the feeder 10 can supply molten glass to the feeder by reducing glass marbles to heabsoftened condition.

At the ends of the feeder 10 are electrical terminals 16 that connect to a source of electrical energy to heat the feeder 10 by conventional resistance heating. Such heating keeps the molten glass in the feeder 10 at fiberforming temperatures and viscosities.

The feeder 10 has a bottom wall 18 with orifices or passageways that deliver the streams of molten glass 12 from the feeder 10. As shown, depending orificed projections 20 define the openings in the bottom wall 18. The feeder 10 is illustrated in a preferred embodiment in which the orificed projections 20 are formed into adjacent straight parallel rows. And the projections 20 in each of the rows are in staggered relation with the projections 20 in the other row.

Spaced a short distance below the bottom wall 18 of the feeder 10 is a blower means in the form of a slotted blower assembly 22. This blower assembly releases blasts of gaseous fluid such as steam, air or other gaseous blowing media for attenuating the molten glass streams 12 into the glass filaments 14.

During attenuation of the molten glass streams 12 by gaseous blasts, the streams 12 are drawn into substantially cone-shaped configurations. Each of the streams 12 in the filament forming region extends in diminishing size from the discharge or exit end of its orificed projection 20 to an apex region 24 (see FIG. 3) at its associated filament 14. Each of the filaments 14 emerge from the apex region 24 of its associated stream 12.

The blower 22 is close to the bottom wall 18. For ex- I ample, the upper portion of the blower 22 is commonly spaced only about three-eighths to three-fourths of an inch below the bottom wall 18. And the position of the apex regions 24 of the cones 12 is normally from onefourth to five-eighths of an inch above the entrance to the blower slot. But the apex region can be within the blower slot. The reference numeral 26 denotes the slot or passageway of the blower 22.

The blower 22 preferably forms two rows of jet or nozzle openings that face each other within the slot 26 from opposing walls and direct individual blasts away from the feeder 10 in the direction of filament attenuation. The individual jet openings in each of the walls are paired and indexed directly opposite each other. Hence, the blasts from the pairs of opposing jet openings intersect and conflow away from the container wall 18 as a row or sheet of blasts.

The space between adjacent blasts are often called holes in view of the absence or minimized effect of the blasts in these regions.

In operation the blasts of gaseous fluid discharged from the blower 22 establish drawing or tractive forces effective to attenuate the streams 12 into the individual glass filaments 14 by drawing them downwardly through the walled slot 26.

Directly below the blower 22 is a receiving hood 30 into which the blower 22 directs the blasts and the filaments 14. The hood 30 is preferably diverging to form a venturi-type throat that serves to expand the gaseous fluid of the blasts and cause their deceleration.

At the bottom of the hood 30 is a traveling conveyor belt 32 that collects the filaments 14 to form a fibrous layer or mat 34. The belt 32 is preferably foraminous to permit passage of the gaseous fluid of the blasts therethrough into a chamber 36 below the belt 32. This gaseous fluid leaves the chamber 36 through a conduit 38. Suction means may be applied to the chamber 36 through the conduit 38 to assist formation of the mat 34 and accelerate discharge of the gaseous fluid from the chamber 36.

At the back end of the hood 30, or other suitable positions, is a spray gun 40 that sprays the glass filaments 14 accumulating on the moving conveyor belt 32 with suitable conventional lubricants or binders, such as a thermosetting resin like phenol formaldehyde or a thermoplastic resin like polystyrene, to unite the filaments 14 into an integral glass filament mat 34. The gun 40 includes supply tubes 42 and 44, one for supplying air under pressure and the other for supplying suitable sizing, binding or other desired liquids to the gun 40.

The fiber forming apparatus disclosed, including the feeder 10 and blower 22, may be put in series with other feeders and blowers along the length of the conveyor 32 to supply additional filaments to the conveyor belt 32.

The construction and operation of the feeder l0 and blower 22 can be more clearly understood when considered in relation to FIGS. 3 through 6.

The blower 22 as illustrated includes separate blower halves in the form of identical blower blocks or housings 50 that are held in spaced apart relationship to form the passageway or walled slot 26 between them.

End plates

52 and 54 hold the blocks 50 in fixed spaced apart relationship.

Each of the blocks 50 has a hollow interior or pressure chamber 56. Suitable conventional means supplies steam, air or other gaseous blowing fluid under desired pressure to the chambers 56 through supply tubes 58 and 59.

Each of the blocks 50 further includes a plurality of small, downwardly disposed nozzle passageways 60 through which gaseous blowing media from the chamber 56 issues as blasts. Partitions 62 separate the individual nozzle passageways 60.

The blower 22 registers the nozzle passageways 60 on opposite sides of the slot 26 against each other so that opposing passageways 60 direct blasts against each other. These blasts merge into a series of spaced apart blasts that are separated by relatively quiet zones or holes into which air is introduced by suction into the slot 26 over the top of the blower 22 (between the feeder 110 and blower 22). Further, the rows of orificed projections are registered with the slot 26 and are preferably arranged so that each stream of molten glass 12 registers with and enters into a relatively quite zone between the spaced apart blasts. Such an arrangement discourages mutual interference by adjacent streams. However, more or less streams than zones may be used. In so doing, individual emerging filaments are drawn through the nearest high velocity zone; however, more than one filament may simultaneously pass through a given zone.

The disposition of the nozzle passageways 60 are important for good filament attenuation. Satisfactory results can be obtained when the interengaging blasts intersect at anincluded angle of from about 20 to 28. Such an included angle is shown as angle A in FIG. 4. Preferably angle A is about 20. For angles less than 20 the blasts do not obtain an effective pulling action. On the other hand, if angle A is greater than about 28, the pulling or tractive forces for attenuating the streams 12 are not effective.

The vertical distance between the blower 22 and the bottom wall 118 of the feeder 10 should permit free flow of induced air to the slot 26. If the blower 22 is too close to the bottom wall 118, a choking effect can occur. In such a condition the closeness of the blower 22 to the feeder M) can restrict air flow to the slot 26; so the blower, in a sense, becomes air starved. Aggravated turbulent air conditions in the filament forming region can occur.

It is noted that one could use or introduce treating gases for contact with the molten glass streams 12 (also, filaments 14). Hence, the blower 22 might draw ambient gases other than air into its slot 26.

A good explanation of the operation of blowers like blower 22 can be found in U.S. Pat. No. 2,206,060. It is noted that it is possible to use a blower releasing a sheet of gaseous fluid such as the type of blower disclosed in U.S. Pat. No. 2,133,236 rather than the blower 22. But a blower like the blower 22 is preferred.

In a broad sense the invention includes means for containing heat-softened filament forming material including a wall and a row of orificed projections extending from the wall. The projections emit streams of heatsoftened filament forming material, for example molten glass, for attenuation into filaments. Further included is means for attenuating the streams into filaments that tends to cause movement of air across the row during attenuation. The orificed projections have thicker wall portions at their windward sides to resist the erosive effect of air movement across the row during attenuation.

In a preferred form the orificed projections have an elongated transverse cross section (taken with respect to their axes of projections) and have their orifice outlets offset towards their leeward sides.

FIGS. 4-6 show in more detail the preferred shape and grouping of the orificed projections 20 on the bottom of the feeder 10 used with the apparatus shown in FIGS. I-3.

The projections 20, as shown, jut normally away from the bottom wall 18 of the feeder 10 to form two distinct spaced apart adjacent parallel straight rows. The orificed projections 24) in each of these rows are in offset or staggered relationship with the orificed projections 29 in the other row.

The transverse cross sectional shape of the projections 20 is more clearly shown in FIGS. 4 and 5 in a preferred form elongated. More specifically the projections are shown with an oval transverse cross section shape. Other transverse cross sectional shapes can be used and are discussed hereinafter.

Each of the projections 20 in each of the rows is disposed with its longitudinal axis of cross section extending in a preferred crossing direction with the other row. As indicated by the upper left projection 20 in FIG. 4, the intersection between the extension of the longitudinal cross sectional axis and the axis of the other row form a right angle denoted as angle B. An angle B of other sizes can also be used.

The projections 20 are in closely grouped relationship. For example, the projections: 20 within each row are normally evenly spaced a distance designated as D1 in FIG. 4. D1 is commonly about one-eighth of an inch. The distance between the rows of projections 20 is normally uniformly spaced a distance designated as D2 in FIG. 4. D2 is commonly about three thirty-seconds to five thirty-seconds of an inch.

The projections 20 themselves are small. For example, the projections normally have a uniform short height designated as H in FIG. 6. H is usually from onesixteenth to three thirty-seconds of an inch.

Each of the projections 20 has an orifice outlet that is offset towards the other row. So each of the projections 20 in each of the rows has a thicker wall portion 72 that faces away from the other row and a thinner wall portion 74 that faces the other row. Usually the passageway through each of the projections 20 extends in a direction parallel to the axis of the projection. And it is usual practice to have both the projections 20 and their passageways extend normally away from the bottom wall 18 of the feeder 10. Further, it is normal practice to use projections 20 all having the same size passageway and consequently the same size passageway outlet.

The thicker outlet wall portions 72 are at the windward side of the projections in each of the rows to provide sufficient wall thickness to effectively withstand the erosion effect from impingement of high velocity air flow induced by operation of the blower 22. And the thickness is provided without significant increase over the dimension of conventional orificed projections. Normally the thickness of the portion 72, shown as I in FIG. 5, is from 1 /2 to 2 /2 times the diameter of the outlet orifice 7%, shown as d in FIG. 5.

The thickness of the thinner outlet wall portions 74, shown as II in FIG. 5, is normally from one-tenth to one-twentieth the diameter d of the outlet orifice 70.

As shown the oval of each of the projections 20 has a considerably greater overall length dimension, shown as L in FIG. 5, than the width dimension of the oval,

shown as W in FIG. 5. For example, L is often from 2 to 4 times greater than W, an L of from 1 /2 to 2 times W is preferred.

The outlet orifice 70 is shown as a circle having its center on the longitudinal axis of cross section of each of the projections 20. But the outlet orifice 70 can be a different shape and can be laterally offset from the longitudinal axis of cross section of each of the projections 20 (see FIG. 13).

The embodiment of the invention shown in FIGS. 1-3 advantageously uses an air barrier or air obstruction means in the form of molten glass bridging the space between immediately adjacent orificed projections 20 within each row. This bridging can be more clearly seen in FIGS. 4 and 6. A web or bridge 80 of molten glass between each of the projections 20 protects the inner thinner wall portions 74 of the projections 20 from the effects of high energy air flow with damaging pollutants such as dust and corrosive gases. The arrows in FIG. 4 indicate the obstructing influence the bridges 80 have on induced air flow. So in each of the rows the glass bridges 80 and the projections 20 themselves combine to form an air flow blocking wall. And this wall protects the thin walled interior portions 74 of the projections 20 in each of the rows from unobstructed impingement of high energy air flow with damaging pollutants such as dust and corrosive gases. The result is a quieter air flow region in the space between the rows; erosion of the projection portions 74 from air flow is drastically reduced.

Bridging of molten glass between immediately adjacent projections 20 within a row occurs for several reasons. The primary reasons are: the inherent higher temperature of the projections 20 at their base regions immediately adjacent the bottom wall 18 visa-vis the temperature of the projections 20 at their discharge ends; the size of the projections 20; the distance between the projections 20; and the ability of the exterior surfaces of the projections 20 and bottom wall 18 to be wetted by the filament forming material, for example molten glass.

During start-up of the feeder the higher temperature of the projections at their base regions promotes a flow of molten glass over the exterior surfaces of the projections 20 to the bottom wall 18. And the height of the projections 20 is sufficiently short for the temperature differences between the base and discharge ends of the projections 20 to allow molten glass to reach the exterior surface of the bottom wall 18. The distance between immediately adjacent projections 20 in each of the rows is sufficiently close to allow molten glass reaching the bottom wall 18 to coalesce or unite into a bridging layer between immediately adjacent projections 20 within each of the rows. Over a short time molten glass continues to coalesce in layers until a bridge or web 80 of substantial height is formed between immediately adjacent projections 20 within a row.

The molten glass of the bridges 80 are believed to be of higher viscosity than the molten glass in the streams 12. In this regard, it is believed that the molten glass of the bridges 80 at the bottom wall 18 may be devitrified.

Referring more particularly to FIG. 6, it can be seen that the glass bridges 80 have curved exposed lower edges 82. Normally the bridges 80 are substantially the height H of the immediately adjacent projections 20;

but the bridges diminish in height to a minimum height, denoted as h in FIG. 6, generally at the midregion between the projections. The height h is usually about from two-thirds to one-third the height H of the immediately adjacent projections 20. The height (both H and h) of the bridges 80 can vary.

The width of the bridges of webs 80 are substantially less than the length L of the projections 20, usually about one-third L.

In operation high velocity air flow induced by operation of the blower 22 flows against the obstruction formed along each row by the bridges 80 and the pro jections 20. The region between the rows is substantially protected. And although the air flow in the region between the rows is turbulent, the energy of the air flow is small compared with the high energy of the unobstructed induced air flow. So erosion of the projections 20 at the thinner wall portions 74 is substantially precluded; the thicker wall portions 72 resist the erosion effect of the air flow.

So during filament attenuation the blower 22 discharges gaseous blasts effective to attenuate the molten glass streams 12 into the glass filaments 14; the blower induces high energy air flow across each of the rows of orificed projections 20 towards the other row. The thicker wall portions of the windward sides of the projections 20 resist the erosive effect of the high energy air movement. The bridging means between the immediately adjacent projections in each of the rows is effective together with the projections 20 themselves to provide a barrier that blocks or obstructs the flow of air across each of the rows towards the other row. So the thinner wall portions 74 of the projections 20 are protected from the erosive effects of the unobstructed high energy of induced air flow during filament attenuation by the blower 22.

FIGS. 7 and 8 show part of a feeder and blower arrangement like the arrangement shown in FIGS. l-6, except for the shape of the feeders orificed projections.

FIGS. 7 and 8 show a feeder supplying two straight rows of closely spaced molten glass streams 112 that are attenuated into glass filaments 114.

At the ends of the feeder 110 are electrical terminals 116 (only one is shown) that connect to a source of electrical energy to heat the feeder 110 by conventional resistance heating.

The feeder 110 has a bottom wall 118 with orifices or passageways that deliver the streams of molten glass 112. As shown, depending orificed projections 120 define the openings in the bottom wall 118. The projections 120 are tapered from a maximum size at their base ends to a minimum size at their discharge ends. And like the orificed projections 20 of the feeder 10, the orificed projections 120 are formed into two adjacent straight parallel rows. The projections 120 in each of the rows are in staggered relation with the projections 120 in the other row.

The transverse cross sectional shape of the orificed projections 120, like the orificed projections 20, is oval. But the size of the oval increases towards the base end of each of the projections. The lengthwise dimension of the oval for each of the projections 120 extends in a crossing direction with the other row to form an intersecting angle of 90 degrees (see angle B in FIG. 4).

The orifice outlets of the projections 120 in each of the rows are offset towards the other row as described in relation to the outlet orifices 70 of the projections 20. So the projections 120 have thicker wall portions at the windward sides of the rows.

The spacing and shape of the orificed projections 120 in each of the rows puts the projections in overlapping relation along the length of the rows at the base ends of the projections. The overlap is indicated as in FIG. 8. The discharge ends of the projections 120 do not overlap.

A blower 122 with a slotted passageway 124 is below the feeder 110. This blower operates to attenuate the filaments 114 like the blower 22 attenuates the filaments 14 from the streams 12 emitted from the feeder 10.

Webs or bridges 180 are between the projections 120. The webs are like the webs 80.

The bridges 180 and projections 120 in each of the rows form a barrier or wall. And this barrier obstructs high energy air flow to the other row as explained in relation to the feeder and blower 22.

FIG. 9 shows a more closely grouped arrangement of orificed projections on the bottom wall 18' of a feeder than the arrangements of FIGS. 18. The projections 20' are shown with their discharge ends 70' forming two intermingled rows. The discharge ends of each of the rows are offset with the discharge ends of the projections in the other row. And the rows are sufficiently close that the individual discharge ends in each of the rows are no further from the immediately adjacent discharge ends in the other row than the edge of the region between immediately adjacent discharge ends. Theregion between immediately adjacent discharge ends is indicated by dashed lines in FIG. 9. As shown in FIG. 9 the outlet orifices 70' do not overlap.

A blower attenuating means is used with the feeder shown in FIG. 9. The blower means and feeder operate as discussed with the other embodiments.

FIGS. 10-14 show various individual orificed projection transverse cross sectional shapes according to the principles of the invention. An orificed projection 220 having an oval cross sectional shape is shown in FIG. 10; the outlet orifice 270 is also oval and is offset on the longitudinal axis of the oval for disposition towards another row of orificed projections.

An orificed projection 320 having a rectangular cross sectional shape is shown in FIG. 11. Its outlet orifice 370 is circular and is offset on the longitudinal center line of the rectangle for disposition towards another row of orificed projections.

FIG. 12 shows an orificed projection 420 having a circular cross sectionshape and a circular outlet orifice 470; the outlet orifice 470 is offset towards another row (not shown) and on a center line intersecting the other row with an angle B (see FIG. 4) of 90. As shown the center of the outlet orifice 470 is offset from the center of the circular shape a distance greater than 0.2 but less than 0.75 the orifice diameter.

FIG. 13 shows a projection 520 like the projection 420, except the outlet orifice 570 of the projection is laterally offset towards another row and laterally offset from the center line. Also, the outlet orifice 570 is oval.

FIG. M shows a isosceles triangle cross section shaped orificed projection 620 with a circular outlet orifice 670. The orifice 670 is on the center line or height of the triangle and is offset for disposition towards another row of orificed projections.

FIG. 15 and 16 show a portion of the bottom region another feeder according to the principles of the invention. As in the case of the other embodiments, the bottom of the feeder includes two spaced apart rows of orificed projections 720 having oval transverse cross sectional shapes like the projections 20. The projections 720 include passageways terminating with orifice outlets 770 offset towards the other row like the arrangement of the projections 20 in FIGS. 1-6. Since the feeder of FIG. 15 and 16 is used with filament attenuating means causing a movement of air across each of the rows towards the other row during attenuation, the projections 720 have thicker wall portions on their windward sides just like the projections 20.

The embodiment shown in FIGS. 15 and 16 includes a ceramic fence 780 for each of the rows. The fences 780 include arcuate collar portions 782 that each surround an orificed projection 720.. The fences 780 as shown are shorter in height than the height of the projections 720.

The fences 780, like the bridges or webs 80 of molten glass, combine with the rows of projections 720 to obstruct the free flow of air across each of the rows towards the other row to protect the thinner wall portions of the projections 720 from the effects of unobstructed high energy of induced air flow. And the thicker wall portions of the windward sides of the projections resist the errosive effects of the air movement.

FIG. 17 shows a plan view of rows of orificed projections on the bottom wall of another feeder according to the principles of the invention. And like the other embodiments, the feeder is to be used with means for attenuating heat-softened streams emitted from the orificed projections into filaments in which such means tends to cause movement of air across the rows.

Three straight parallel rows of orificed projections are shown. The center row is made-up of conventional cylindrical orificed projections 81.6 that include concentric outlet orifices 818. The outside rows are madeup of elongated (oval transverse cross sectional shape) orificed projections 820 that are like the orificed projections 20. The orifice outlets 870 of the projections 820 are offset like the outlets of the projections 20 and are disposed like they are shown in FIGS. 1-6. Since the feeder of FIG. 17 is used with filament attenuating means causing a movement of air across the rows during attenuation, the projections 820 have thicker wall portions on their windward sides.

Further, there are webs or bridges 880 of molten glass between immediately adjacent projections 820 in each row (and bridges 880 between the projections 816).

The bridges or webs 880 of molten glass, combine with the rows of projections 820 to obstruct the free flow of air across each of the rows towards the middle row of projections 818. And the thicker wall portions on the windward sides of the projections 820 resist the erosive effects of the air movement.

I claim:

1. Apparatus for producing filaments from heatsoftened filament forming material comprising:

means for containing heat-softened filament forming material including a wall and a row of orificed projections extending from the wall for emitting streams of heat-softened filament forming material for attenuation into filaments; and

means for attenuating the streams into filaments,

such attenuating means tending to cause movement of air across the row during attenuation, the orificed projections having thicker wall portions at their windward sides to resist the erosive effect of air movement across the row during attenuation.

2. Apparatus for producing filaments from heatsoftened filament forming material comprising:

a container for holding heat-softened filament forming material, a row of orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments; and

means for attenuating the streams into filaments,

3. The apparatus of claim 2 in which the means for attenuating the streams into filaments is a blower means.

4. The apparatus of claim 3 in which each of the thicker wall portions have the same thickness.

5. The apparatus of claim 4 in which the orificed projections extend downwardly from the bottom wall of the container.

6. The apparatus of claim 5 in which the projections have an elongated transverse cross section.

7. Apparatus for producing filaments from heatsoftened filament forming material comprising:

a container for holding heat-softened filament forming material, orificed projections extending from a wall of the container for emitting streams of heats oftened filament forming material for attenuation into filaments, the orificed projections forming two adjacent rows; and

means for attenuating the streams into filaments,

such attenuating means tending to cause movement of air across each of the rows towards the other during attenuation, the orificed projections in each of the rows having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation.

8. Apparatus for producing filaments from heatsoftened filament forming material comprising:

a container for holding heat-softened filament forming material, orificed projections extending from a wall of the container for emitting streams of heatsoftened filament forming material for attenuation into filaments, the orificed projections forming two adjacent rows, the projections in each of the rows being offset with corresponding projections in the other row; and

blower means for supplying a gaseous blast effective to attenuate the streams into filaments, such blower means causing movement of air across each of the rows towards the other during attenuation, the orificed projections in each of the rows having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation.

9. Apparatus of claim 8 in which the orificed projections have elongated transverse cross sections disposed with their lengthwise dimensions extending in a direction towards the other row.

10. Apparatus of claim 9 in which the orifice outlets of the projections in each of the rows are offset lengthwise of their transverse cross sections towards the other row.

11. Apparatus of claim 8 in which the rows are spaced apart.

. 12. Apparatus of claim 8 in which the rows are intermingled.

13. Apparatus of claim 8 in which the rows are straight.

14. Apparatus for producing glass filament comprising:

a container for holding molten glass, orificed projections extending downwardly from the bottom wall of the container for emitting streams of molten glass for attenuation into filaments, the orificed projections forming two spaced apart parallel straight rows, the projections in each of the rows being offset with corresponding projections in the other row; and

blower means spaced below the container for supplying gaseous blasts effective to attenuate filaments downwardly from the streams, the gaseous blasts causing a flow of air across each of the rows towards the other row during attenuation of the filaments, the offset projections in each of the rows have elongated transverse cross sections, each of the offset projections being disposed with its lengthwise cross sectional dimension extending in a direction towards the other row and having its orifice outlet offset towards the other row to provide a thicker wall portion at its windward side to resist the erosive effects of the air movement.

15. Apparatus of claim 14 in which the transverse cross sections of the orificed projections are oval.

16. Apparatus of claim 15 in which the orificed projections extend normally away from the bottom wall.

17. Apparatus of claim 16 in which the individual passageways through the individual orificed projections extend in a direction parallel to the axes of projection of their projections.

18. Apparatus of claim 17 in which the passageways of the orificed projections are offset on the longitudinal axes of the transverse cross sections of such projections.

19. Apparatus for producing filaments from heatsoftened filament forming material comprising:

blower means for supplying a gaseous blast effective to attenuate the streams into filaments, such blower means causing high energy air flow across each of the rows towards the other row during attenuation, the orificed projections in each of the rows having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation, the orificed projections being of sufficient size and spaced relationship within each of the rows and the surfaces of the bottom wall and the projections being sufficiently wetable by the molten glass to promote formation of the bridge of molten glass between immediately adjacent orificed projections within each row effective to obstruct the movement of the air across the rows during attenuation.

20. Apparatus for producing filaments from heatsoftened filament forming material comprising:

a container for holding heat-softened filament forming material, orificed projections extending from a wall of the container for emitting streams of heat softened filament forming material for attenuation into filaments, the orificed projections forming two adjacent rows, the projections in each of the rows being offset with corresponding projections in the ing attenuation.

Claims

1. Apparatus for producing filaments from heat-softened filament forming material comprising: means for containing heat-softened filament forming material including a wall and a row of orificed projections extending from the wall for emitting streams of heat-softened filament forming material for attenuation into filaments; and means for attenuating the streams into filaments, such attenuating means tending to cause movement of air across the row during attenuation, the orificed projections having thicker wall portions at their windward sides to resist the erosive effect of air movement across the row during attenuation.

2. Apparatus for producing filaments from heat-softened filament forming material comprising: a container for holding heat-softened filament forming material, a row of orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments; and means for attenuating the streams into filaments, such attenuating means tending to cause movement of air across the row during attenuation, the orificed projections having thicker wall portions at their windward sides to resist the erosive effect of air movement across the row during attenuation.

7. Apparatus for producing filaments from heat-softened filament forming material comprising: a container for holding heat-softened filament forming material, orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments, the orificed projections forming two adjacent rows; and means for attenuating the streams into filaments, such attenuating means tending to cause movement of air across each of the rows towards the other during attenuation, the orificed projections in each of the rows having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation.

8. Apparatus for producing filaments from heat-softened filament forming material comprising: a container for holding heat-softened filament forming material, orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments, the orificed projections forming two adjacent rows, the projections in each of the rows being offset with corresponding projections in the other row; and blower means for supplying a gaseous blast effective to attenuate the streams into filaments, such blower means causing movement of air across each of the rows towards the other during attenuation, the orificed projections in each of the rows having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation.

11. Apparatus of claim 8 in which the rows are spaced apart.

12. Apparatus of claim 8 in which the rows are intermingled.

13. Apparatus of claim 8 in which the rows are straight.

14. Apparatus for producing glass filament comprising: a container for holding molten glass, orificed projections extending downwardly from the bottom wall of the container for emitting streams of molten glass for attenuation into filaments, the orificed projections forming two spaced apart parallel straight rows, the projections in each of the rows being offset with corresponding projections in the other row; and blower means spaced below the container for supplying gaseous blasts effective to attenuate filaments downwardly from the streams, the gaseous blasts causing a flow of air across each of the rows towards the other row during attenuation of the filaments, the offset projections in each of the rows have elongated transverse cross sections, each of the offset projections being disposed with its lengthwise cross sectional dimension extending in a direction towards the other row and having its orifice outlet offset towards the other row to provide a thicker wall portion at its windward side to resist the erosive effects of the air movement.

19. Apparatus for producing filaments from heat-softened filament forming material comprising: a container for holding heat-softeNed filament forming material, orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments, the orificed projections forming two adjacent rows, the projections in each of the rows being offset with corresponding projections in the other row; and blower means for supplying a gaseous blast effective to attenuate the streams into filaments, such blower means causing high energy air flow across each of the rows towards the other row during attenuation, the orificed projections in each of the rows having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation, the orificed projections being of sufficient size and spaced relationship within each of the rows and the surfaces of the bottom wall and the projections being sufficiently wetable by the molten glass to promote formation of the bridge of molten glass between immediately adjacent orificed projections within each row effective to obstruct the movement of the air across the rows during attenuation.

20. Apparatus for producing filaments from heat-softened filament forming material comprising: a container for holding heat-softened filament forming material, orificed projections extending from a wall of the container for emitting streams of heat-softened filament forming material for attenuation into filaments, the orificed projections forming two adjacent rows, the projections in each of the rows being offset with corresponding projections in the other row; and blower means for supplying a gaseous blast effective to attenuate the streams into filaments, such blower means causing high energy air flow across each of the rows towards the other row during attenuation, the orificed projections in each of the rows having thicker wall portions at their windward sides to resist the erosive effect of air movement during attenuation, bridging means between immediately adjacent orificed projections within each row effective together with the projections to obstruct the movement of the air across the rows during attenuation.