US2839784A - Method and apparatus for the production of filaments - Google Patents

Description

June 24, 1958 H. WEBER ETAL 2,839,784

METBOD AND APPARATUS FOR THE PRODUCTION OF FILAMEI ITS Filed March 26, 1953 2 Sheets-Shee t 1 FIGJ.

I I INVENTORS. 34a HAROLD WEBER 26a WALTER D. PAIST Y M114 4 TTORNEYS.

June 24, 1958 WEBER ET AL METHOD AND APPARATUS FOR THE PRODUCTION OF FILAMENTS Filed March 26, 1953 2 Sheets-Sheet 2 I NVENTORS. HAROLDWEBER WALTER D. PAIST Q 2,839,784 ICC Patented J n 24,1

METHOD AND APPARATUS FOR THE PRODUCTION OF FILAMENTS Application March 26, 1953, Serial No. 344,738

17 Claims. (Cl. 18-8) This invention relates to the production of filamentary materials and relates more particularly to the production of a-rtificialfilaments from comminuted fusible filament-forming materials.

' One method heretofore employed for the production of artificial filaments from comminuted filament-forming material involved urging the material in powdered form, ,by means of a tamper, against one side of a heated plate having spinning orifices therein so that the powdered material is fused by heat supplied from said plate, supplying fresh powdered material to the plate, and drawing away the fused material through said orifices inthe form of filaments. Although satisfactory filaments have been spun in this manner the uniformity of the filaments has not been as high as desired.

1 It is an object of this invention to provide anovel apparatus and process for the production of artificial filaments from comminuted fusible filament-forming materials. e

Afurther object of this invention is the provision of a new and improved apparatus and process of this character for producing filaments of greater uniformity,

than is obtainable with the apparatus and process of the prior art. Other objects of this invention will appear fromthe following description and claims.

According to this invention particles of fusible filament-forming material are forced through the orifices of a heated spinning jet by a plurality of rams having working faces'acting against said jet. The rams apply a continuous mechanical pressure to the particles on one side of a layer of'the material in contact with the jet so as to urge said particles towards said jet, whereby the particles are fused by heat supplied from the jet, and the fused material is continuously drawn through the orifices of the jet in the form of filaments. This mechanical pressure, although applied continuously to said layer'of material, is applied intermittently to difierent areas of said layer, and fresh particles of material are supplied to said areas during the periods of time between successive applications of the mechanical pressure thereto.

More particularly, the spinning jet is in the form of a long, electrically heated plate having a plurality of spinning orifices and is situated immediately below a long slit at the bottom of a chamber. Powdered filamentof elongated rams, each having onefiat side and each having a working face extending substantially the entire length of the slit, the rams being arranged between guides forming material is urged against this plate by a pair in the chamber with the flat sides of the rams in close ram, after which the first ram is raised and then moved down to apply a tamping force to said layer while the second ram is still being pressed forcibly against said layer. This sequence of operations is repeated several times per second. The powdered material in contact with the jet plate is fused by the heat supplied by said plate and is drawn off through the orifices of said plate, while the upper particles of the layer, of material adjacent to the plate, i. e. the particles in contact with said rams, remain unfused until they are forced closer to the plate by repeated downward movements of the rams against fresh powdered material which is intermittently supplied to the top of said layer. Thus, when a ram is raised a small quantity of fresh powdered material fiows, by gravity, under said ram to make up for the molten material force through the jet plate by said ram during its downward stroke.

The drawing away of the fused material passing through the jet plate may be effected by simply allowing the products emerging from the orifices in the heated plate to fall away by their own weight. Except inthe production of bristles and like heavy filament-ary products, however, it is desirable to draw the fused material away at a greater linear rate, as by passing the filaments around a draw-roller driven at the appropriate peripheral speed and disposed atia suificient distance from the heated plate for the filaments to harden by cooling. I e

The filamentary'products made in accordancewith the invention can thus be in the form of a bundle of fine filaments, e. g. of 10 denier down to 1 denier or less, associated together to form a thread which can be twisted to any desired degree or, alone or in association with other such threads, can be converted into staple fibers for use in staple fiber yarns. Alternatively, however, filaments of heavy denier (e. g. of 10-200 denier) can be made, suitable for employment'singly or in small groups in the manner of yarns for textile'purposes. ,By the use of a single orifice in the plate, still heavier filaments of up to 4000 denier or more can be produced for such purposes as bristles. Again, by providing an orifice in the plate in the form of a slit, narrow bands] or ribbons, or strawlike products can be made, of a width of the order of 1 to 5 mm. or more. '1 Such products The degree of draw-down employed for the production offine filaments, i. e. the ratio between the area of cross-section of the orifices in the .plate and the area of cross-section of the filaments, is preferablyof the order of 500 to 1000 or more. For heavy filaments, however, a lowerdegree of draw-down can be employed, ranging from unity upwards according to the denier of the products required. The possibility of using a high degree of draw-down makes it unnecessaryto use very fine orifices in the plate, and; enables the same orifices to be used for filaments of verydifie-rent deniers. Thus, orifices of the order of '0.0 2"or more in diameter, which offer no special difficulty in production, can be used, and the denier of the resulting filaments determined by the degree of draw-down, However, the properties of the filaments vary with the degree of draw-down; for example, when a lower degree of draw-down is employed the resulting filaments may exhibit a higher elongation at break. 3 e I I I,

From the draw roller by which the draw-down is effected, the filaments proceed to .-a collecting device,

e. g. to a simple reel or, in the case of a bundle of filaments to be formed into acontinuous filamentyarn, to acentrifugal pot or other twisting and winding device. on their w f m. he hea e P a t he. allsq s 9- yice, the filaments may be treated with an antistatic lubricant or other finish. The method and apparatus described above can be successfully operated in air at atmospheric pressure. tain advantages can be obtained, however, by maintaining an atmosphere of" an inert gas (e. g. of nitrogen) about the powdered material that has been supplied to the plate, particularly as regards the range of temperatures to which the plate may be heated without damage to resulting filaments by charring, excessive bubble formation or other defects. For this purpose the vessel into which the powdered material is fed for delivery to the heated plate may be provided with a closure and with a supply pipe for feeding the inert gas. his not desirable, in general, to'jmaintain the powdered material supplied under a superatmospheric gaseous pressure, whether of air or of inert gas, since it has been found that the use of such pressure greatly increases a tendency toward the formation of numerous small bubbles of gas in the resulting filaments, giving them an opaque appearance and a much reduced specific gravity. Insofar, however, as filamentary products of this charcter may be desirable for certain purposes, e. g. for thermal or electrical insulation, the use of pressure affords a convenient means of obtaining them.

Certain other advantages may be obtained by maintaining a sub-atmospheric pressure about the powdered material that has been supplied to the heated plate, particularly as regards the range of temperatures to which the plate may be heated without damage due to charring or other decomposition of the material, and as rega'rds the range of properties obtainable in the resulting filaments; Thus, when the powdered material'is cellu lose acetate and sub-atmospheric pressure is employed, the temperature may range upwards from the lowest temperature at which the production of satisfactory filaments is possible to a temperature which is higher by 80 to Cer 100 C. The use of higher temperatures increases the rate (in weight per unit time) at which the filaments are produced and the ease with which they can be drawn away from the orifices in the heated plate. Also, the availability of a wide range of practicable temperatures enables'filaments of widely different characters to be obtained, from filaments of high tenacity and relatively low extensibility produced at low temperatures, to filaments of lower tenacity but'greater extensibility produced at higher temperatures. Moreover, the use of sub-atmospheric pressure this way enables a still wider range of materials to be spun into filaments from the molten condition. If desired, an inert gas at sub-atmospheric pressure may be used.

By the use of this invention substantially uniform filamentary products can be produced successfully from a number of fusible filament-forming substances, including not only substances which are stable at and above their melting points, but also many which are liable to slow decomposition and discoloration if maintained for a substantial period at about the temperature at which they first become'flowable. The method of the present invention does not require the material to hem a flowable state for more than a very short period of time. The time during which the filament-forming material is being urged towards the jet face, in the form of apparatus described above, is of the order of 1 minute or less, and the material is subjected to a temperature approaching that of the heated jet plate for only a fraction of that time. The very short period of heating enables melt spinning of materials of the type mentioned above to be ing point at normal pressure of the mixture.

7 Z ability over a range of temperatures. When using materials with sharp melting points it is often preferable to employ a substantial degree of draw-down. The materials which have not a sharp melting point, however, can in general be spun quite readily without substantial draw-down (i. c. with no more than that caused by the weight of the extruded product) to form heavy bristles. As has already been mentioned, cellulose acetate is an example of the materials to which the invention can be applied. The cellulose acetate used may be a fully acetylated or partially deacetylated (e. g. acetone-soluble) product. Although, as pointed out above, the material is subjected to a high temperature for only a very short time, it is desirable to take reasonable steps to stabilize the material against heat-decomposition. Accordingly, when using a partially deacetylated cellulose acetate, it is preferred to use a hot-ripened material, i. e. one deacetylated by ripening at a temperature substantially above room temperature, preferably after neutralizing part or all of the sulphuric acid employed as a catalyst in the acetylation process. Further, the cellulose acetate used is preferably one which, after ripening, has been stabilized by heating under pressure with Water or very dilute acid to a temperature substantially above the boil- A further measure, which is applicable to a'number of different materials and which makes easier the production of filarnentary products in accordance with the invention, is to heat the air-dry powdered material in the air or in vacuum, e. g. in the case of cellulose acetate to a temperature of to 200 C. for a period of /2 to hour. The cellulose acetate may be employed with or without a content of plasticizer such as triphenyl phosphate or dimethoxy ethyl phthalate. Suitable stabilizers for' the cellulose acetate such as epoxy resins, metal salts, phenolic compounds, etc., may be used.

The materials employed are supplied for the purpose of the invention in powder form. The fineness of the powder is not critical so long as it is not too coarse to pass into the layer of material in contact with the heated plate, nor so fine as to clog the apparatus or to give rise to difficulties in handling through blowing about or being drawn away through the vacuum pipe, which is used to place the particles under sub-atmospheric pressure. It has been found satisfactory to use a powder, the particle diameters of which are of about the same order as the diameter of the spinning orifices in the heated plate. Thus, with orifices of a diameter of 0.025 inch it has been found practicable to use a powder which will pass through'a gauze having 30 openings per lineal inch but is retained by one having 60 openings per lineal inch.

It has been found that the rate at which the material may be caused to flow through the fine orifices in the plate may be greatly increased by countersinking these orifices, so that the material flowing over the heated plate passes over an inwardly tapered upper portion of the orifice and then, for a very short distance, through the minimum diameter of said orifice. Thus, a plate having a thickness of .030 inch may be provided with orifices having a diameter of .004 to .010 inch the orifices being countersunk at an inclusive angle of 50 to 55 so that the actual length of the narrowest portion of the orifice is only .005 inch.

Materials other than cellulose acetate from which filaments' may be produced according to the present invention include other cellulose esters such as cellulose propionate, cellulose :acetate-pr'opionate and cellulose acetatebutyrate; .cellulose' ethers, such as 'ethyl cellulose and benzyl cellulose; addition polymers such as polyethylene and polystyrene; other polymers, such as polyhexamethylene-hept'amethylene urea obtained from hexamethylene diisocyanate and heptamethylene'diamine, 4,4-polyurethane from tetr-amethylene diamine and 1,4-butanediol bis- (chloroformate) polyhexamethylene adipamide, pol-y '2'2 of Fig. l, and

aminocaproic acid and other polyamides, polyethylene glycol terephthalate and other polyesters, and polyaminotri-azoles, such as those from sebacic dihydrazide and hydrazine.

The powdered form in which the materials are supplied makes it possible to use mixtures of different materials by mixing together the separately powdered materials or to use mixtures of the powdered filament-forming materials with other material, such as powdered pigments. Thus, a mixture of 95% acetone-soluble cellulose acetate with 5% of the polyaminotriazole mentioned, and a mixture of 50% of cellulose acetate with 50% of 66 nylon, and a mixture of 90% of cellulose acetate and of cellulose propionate of propionyl value 63.4 have been successfully formed into bristles and drawn down into fine filaments. Further, filamentary products exhibiting colored or other desirable effects can be produced by mixing with the powdered or granular filament-forming material powdered or granular dyestuffs, or white or colored pigments, or other effect materials, the added materials being incorporated in the filamentary products as a consequence of the process of their production.

A preferred embodiment of this invention is shown'in the accompanying drawing wherein Fig. l is a front elevational view, with parts broken away, of the apparatus of this invention,

Fig; 2 is a cross-sectional view taken along the line Fig. 3 is a detail view, in perspective, of the rams used in theiapparatus of this invention. I Referring now to the drawing, reference numeral 10 designates a spinning'apparatusof this invention having a machine frame 11 carrying a hopper 12, said frame being mounted, by any suitable means, such as' bolts 13 passing through brackets 14, on a channel iron support 16. Comr'ninuted thermoplastic material is placed in the hopper 12 6 bars. The bars 31, 31a are connected to means for reciprocating the same, to be described below, by posts 37, 37a welded, brazed or soldered to saidbars intermediate the ends thereof. The posts 37, 37a comprise cylindrical heads 38, 38a, stems 39, 39a, and nipples 41, 41a adapted to be received in semicircular grooves or holes 42, 42 a in the bars 31, 31a, said grooves being so located that when said bars are mounted between the guides 36 all of the posts 37, 3721 are in the same plane. To enable the'bar's 31, 31a to be reciprocated without interfering with each other a portion of each bar is cut out at 43, 43a, opposite the points where the posts are attached to the other bar. The bars 31, 31a are beveled as shown at 44, 44a, 45 and 45a to permit the comminuted material to move more free ly around the rams and towards the jet plate 24, the nipples-41, 41a being beveled in a similar manner.

The posts 37, 37a are operatively connected to a drive shaft 46, situated at the top of the machine frame 11, by means of eccentrics 47, 47a, pins 48, couplings 49, connecting rods 51, lost motion connections 52, tie rods 53 and collars '54. More specifically, the stems 39, 39a of the posts are mounted in sleeves 56 (Fig. 2) of packing nuts 61. The positions of the collars 54 relative to the and passes down, 'by gravity, into an elongated tamping chamber 17 supported by said hopperand'communicating, at its upper centralportion '18, with the lower portion 19 of said hopper. "The thermoplastic material passes through the tapered lower'portion of the chamber 17 and is forced out ofa long slit-like'opening 22 (Fig. 2) at the bottom of said chamber andthrough the orifices '23 of. a heated jet plate 24by the reciprocating action of I alternately operating tampers or rams 26 and'26a, which are located within the chamber 17 and extend for substantially the'entire length thereof. The jet'plate 24 also extends'for substantially the entire length of the chamber 17 and is'mounted between a cover strip 27 and a supporting .strip .28, both made of electrical 'insulatingmaterial', the

' material forced against said plate by the action of the rams The reciprocating action of the rams 26,2611 also serves to distribute .the thermoplastiematerial, which enters at the central portion of the chamber. 17, throughout the length of said chamber so that the material is forced throughthe orifices of the plate 24'along theentire length of said plate.

The rams comprise long bars 31, 31d (Fig.3) having working faces 32, 32a, flat sides 33, 33a, and thickened upper portions 34,341 The bars 31, 31a are adapted to be mounted so that their working faces 32, 33a may be reciprocated toward and'awjay from the jet plate-24 with the fiat sides 33, 33a in sliding contact witheach.-' To maintain the bars 31, 31a in the Tdesiredr'elationship there are provided guides 36 which engage the outer surfaces of the uppenportions 34, 34a adjacent to the ends'of said tie rods 53 may be variedby loosening the lock nuts 61 and rotating said collars, such rotation of the collars54 being permitted by the connections between said collars and the heads 38, 38a of the posts 37, 37a. The assembly of tie rods 53, collars 54 and rams 26, 26a is urged downwards by means of strong compression springs 62,'whose lower ends abut'againstflanges 63 on said tie rods and whose upper ends abut against adjustable nuts 64'mounted on threaded sleeves 66, which are fixed in any suitable the frame 11. a

'The lost-motion connections'52 comprise pins 69 carried by the tie rods 53 and fitting in slots 71 in the enlarged ends of the connecting rods 51, the latter being slida'bly mounted within bearings 72 in the sleeves 66. By virtue of these lost motion connections the upward movement of the connecting rods 51 lifts the tie rods 53 and the rams 26, 26a against the action of the springs 62 while the downward motion of said connecting rods permits the springs to actuate the rams downwardly to perform their t'amping action. Thus, the working face 32-, 32a of eachram 26, 26a is raised to substantially th'e'same predetermined position upon each revolution of the shaft 46. This position is adjustable relative to the jet plate 24 by means of'th-e threaded connections between connecting rods 51 and couplings &9 and also by means of the threaded connections between'the collars 54 and the tie rods 53. Normally, the position to which the working faces of the rams are lifted is about 7 in. above the upper surface ofthe plate 24. The rams 26, 26a descend, however, only so far as the thickness of the layer of material lying over the jet plate will permit, the lostmotion connections 52 allowing the residual movement of the connecting rods 5'1, under the influence of the eccentrics 47, 47a, to take place independently of the tamper rods and tampers. The lowest possible position of the tie rods 53 and working faces 32, 32a is determined by the adjustment of the collars 54 which act as stops engaging the upper surfaces of the packing glands One pair of eccentrics 47 is mounted on the shaft 46 at a position removed from the other pair'of eccentrics 47a, so that when both of the eccentrics 47 are in their highest position both of the other eccentrics 47a are in their lowest position. Accordingly, when the ram 26 is raised to'its highest position, the other farm 26a is being pressed, under the action of the springs 62, against the comminut'ed rnaterial above the jet plate 24. The lost motion connections 52 are so proportioned and the parts are so adjusted that a ram 26 or 26a is under the influence of its operating pair of eccentrics 47 or 47a for only a relatively small fraction e. g. one sixth, of the cycle of operation, the rams being free to move in a downwards direction under the action of the springs 62 for the remainder of the time. 'It is readily seen that for a major portion of the cycle of operation both rams 26 and 26a are pressing against the powdered material above the plate 24 while for two spaced minor portions of the cycle this material is under the pressure of only one of the rams.

The orifice-s 23 in the jet plate 24 are preferably arranged in staggered relationship in two spaced rows, the rows being, for example, .050 or .070 inch apart, each row being directly under a working face 32, 32a. However, since the rams 26, 26a are side by side, the pressure of any one ram, transmitted through the powdered material, urges the material over both rows of orifices 23 in a downward direction.

The quantity of fresh material entering beneath a working face 32, 32a depends upon the space created between said face in its uppermost position and the upper surface of the layer of material over the plate 24. If the material should enter beneath the face 32 or 32a at a greater rate than that at which it was being drawn away from below the plate 24 in the form of filaments, the thickness of this layer of material would increase, the clearance created beneath the face 32 or 32a would decrease, and the rate of supply of fresh material would correspondingly diminish. Consequently, in the operation of the apparatus there is a balance between the rate of withdrawal in the form of filaments and the rate of supply of fresh powdered material to the upper surface of the plate 24. V

" It is desirable to maintain the material in the chamber 17 under sub-atmospheric pressure. To this end, said chamber is fitted with a vacuum line 76 connected to a suitable vacuum pump (not shown), the opening 77 of the vacuum line being shielded by a baffle plate 78 so that the thermoplastic material will not be drawn into said line. A second vacuum line 79 is provided in the upper portion of the hopper 12 to enable the pressure in said hopper to be reduced quickly, particularly when starting up the apparatus. To aid in maintaining the sub-atmospheric pressure in the chamber 17 there is provided in the gland 57 a seal 80; while the hop-per 12, the walls of said chamber and the connection between said hopper and said chamber are all made substantially air tight, and the hopper is equipped with a removable airtight cover (not shown). In practice, the hopper 12 is filled with the powdered filament-formingmaterial, the hopper cover is closed, and the upper vacuum line 79 is connected to a vacuum pump until there is a vacuum of 28 inches of mercury in the hopper. Following this, the lower vacuum line 77, which has heretofore been closed by any suitable valve, is connected to the vacuum pump and the tamping mechanism is placed in operation.

In the practice of this invention, several spinning machines 10 are operated from a single shaft 46 and means are provided whereby the rams 26, 26a of any one machine may be disconnected from said shaft without interfering with the rotation of the latter. To this end, the apparatus includes a plate 81 supported at one side by a pair of pivot pins 82 mounted on the frame 11, said plate having apertures 83, adapted to receive the tie rods 53, and having projections 84 adapted to engage the under sides of the flanges 63 of said tie rods when said projections are moved upwards by the rocking of said plate. The other side of the plate 81 is supported on an cecentric cam 86 which is keyed to a shaft 87 'journalled at the end of brackets 88 which depend from the L- girder 67 of the frame L Rotation of the shaft 87,

by means of a long handle 89 keyed thereto, causes the .cam 86 to rotate, thus rocking the plate 81 to lift the tie rods 53 against the action of the springs 62. When the parts are thus lifted the rotation of the drive shaft 4-6, and the resulting reciprocation of the connecting rods 51, has no effect on the tie rods 53, all of the motion of said connecting rods being taken up in the lost-motion connections 52. Accordingly, the collars 54 may be unscrewed'from the tie rods 53 and may be disconnected from the posts 37, 37a by removing the pins 59; the gland 57 may be unscrewed from the cover 58; and the rams 26, 26a may be taken out of the vessel 17 for cleaning or replacement.

In order to prevent undue transfer of heat from the ends of the jet plate 24, insulation 91 is provided at both ends of the chamber 17. Because of the fact that the chamber 17 is suspended, at its center, from the hopper 12, the ends of said chamber are free from any bolts or other connections which would act to carry away the heat. It is also desirable to provide insulation (not shown) around the sides of the chamber 17.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Apparatus for the production of artificial filamentary products'from particles of fusible filament-forming material, said apparatus comprising a chamber for receiving particles of fusible filament-forming materiaLa heated spinning jet at an opening of said chamber, a plurality of rams within said chamber, each of said rams having a working facevfor applying mechanical pressure directly against a layer of said particles on said jet to urge said particles toward said spinning jet, and means for recipro eating said rams to apply said'mechanical pressure continuously, said means being so constructed and arranged that said rams move alternatively with at least one ram exerting a pressure against said jet throughout the cycle of operation of said rams and with a plurality of rams exerting simultaneous pressures against said jet for a major portion of said cycle.

2. Apparatus for the production of artificial filamentary products from particles of fusible filament-forming material, said apparatus comprising a chamber for receiv-.

ing particles of fusible filament-forming material, a heated spinning jet at an opening of said chamber, said spinning jet having a spinning orifice, a plurality of parallel rams within said chamber, each of said rams having a working face forapplying mechanical pressure directly against a layer. of said particles on said jet to urge said particles toward said orifice, and means for reciprocating said rams to apply said mechanical pressure, said means being constructed and arranged to move said r-ams alternately.

3. Apparatus for the production of artificial filamentary products from particles of fusible filament-forming material, said apparatus comprising a chamber for receiving particles of fusible filament-forming material, a jet plate at an elongated opening of said chamber, means for fusing said filament-forming material in passing toward said jet plate, a plurality of elongated rams extending the length of said opening, said rams being within said chamber and having working faces acting directly against a layer of said particles on said jet plate, and means for reciprocating said rams to apply mechanical pressure continuously to the particles of material adjacent to said jet plate, said means being so constructed and arranged that said rams move alternately with at least one ram exerting a pressure against said jet throughout the cycle of operation of said rains and with a plurality of rams exerting simultaneous pressures against said jet for a major portion of said cycle.

4. Apparatus for the production of artificial filamentary products from particles of fusible filament-forming rams being within said chamber and having working faces acting against said jet, and means for reciprocating said rams-to apply mechanical pressure directly to the particles of material adjacent to said jet and so that said flat sides move relative to each other.

5. Apparatus for the production of artificial filamentary products from particles of fusible filament-forming material, comprising an elongated chamber for receiving particles of fusible filament-forming material, an elongated heated spinning jet at an elongated opening of said chamber, a pair of elongated rams within said chamber, each of said rams having a working face extending substantially the length of said opening and acting against said jet, said rams having elongated fiat sides and being arranged with said flat sides in contact with each other so that the working face of one ram extends over only a portion of the width of said opening and the working face of the other ram extends over another portion of said width, and means for reciprocating said rams to apply mechanical pressure directly to adjoining areas of the particles of material adjacent to said jet, said means being constructed and arranged to move said rams alternately. I

6. Apparatus as set forth in claim in which the means for reciprocating the rams includes a plurality of posts connected "to said rams, all of said posts being ar-' ranged in one plane.

7. Apparatus for the production of artificial filamentary products from particles of fusible filament-forming material, said apparatus comprising a chamber for receiving particles of fusible filament-forming material, a heated spinning jet at an opening of said chamber, a ram within said chamber and having a working face acting against said jet, means for reciprocating said rain to apply mechanical pressure directly to the particles of material adjacent to said jet, said means including resilient means urging said ram towards said jet, reciprocating means, a lost-motion connection between said resilient means and said reciprocating means, and additional means for urging a portion of said lost-motion connection in a direction to hold said resilient means inoperative.

8. Apparatus for the production of artificial filamentaryproducts from particles of fusible filament-forming material, comprising an elongated tapered chamber for receiving particles of fusible filament-forming material, an elongated heated spinning jet at an elongated opening of said. chamber, said chamber being tapered to said spinning jet, a pair of elongated tapered rams centrally located within said chamber, each of said rams, said rams being tapered in the same direction as said chamber and having a working face extending substantially the length of said opening and acting against said jet, said rams having elongated flat sides and being arranged with said flat sides in contact with each other so that the working face of one ram extends over only a portion of the width of said opening and the working face of the other ram extends over another portion of said width, and means for reciprocating said rams to apply mechanical pressure directly and continuously to the particles of material adjacent to said jet, said means being constructed and arranged to move said rams alternately, said means includ inga plurality of posts connected to said rams, all of said posts being arranged in one plane, said means also ineluding spring means urging said rams toward said jet, reciprocating means and a lost-motion connection between said spring means and said reciprocating means,

the construction and arrangement being such that said rams move alternately with at least one ram exerting a pressure against said jet throughout the cycle of operation of said rams and with both rams exerting simultane- .ous pressures against said jet for a major portion of said cycle. l

'9,"A pparatus for the production of artificial filamentary'products from particles of'fusible filament-forming material, said apparatus comprising an elongated chamsaid'chambeneach of said rams having a working face extending substantially the length of said opening and acting against saidjet; said rams having elongated 'flat sides'and being arranged with said flat sides in contact with each other so that the working face of the ram extends over only a portion of the width of said opening andtheworking face of the other ram extends over another portion of said width, and means for reciprocating said rams to apply mechanical pressure directly and continuously to the particles of material adjacent to said jet, said means being constructed and arranged to move said rams alternately, said means including a plurality of posts connected to said rams, all of said posts being arranged in one plane, said means also including spring means urging said rams toward said jet, reciprocating means and a lost-motion connection between said spring means and said reciprocating means, the construction and arrangement being such that said rams move alternately with at least one ram exerting a pressure against said jet throughout the cycle of operation of said rams and with both rams exerting simultaneous pressures against said jet for a major portion of said cycle, said jet having a plurality of orifices each of which is countersunk on-the side of the jet toward said ram.

10. A process for the production of artificial filamentary products from comminuted fusible filament-forming materials, said process comprising applying a continuous mechanical pressure directly to the particles of materials on one side of a layer of filament-forming material in contact with a heated jet having a spinning orifice therein so as to urge said particles towards said orifice whereby said particles are fused by heat supplied from said jet, said continuous mechanical pressure being applied toward said orifice intermittently to different areas of said layer, continually supplying fresh powdered material to said areas between successive applications of said pressure thereto and continuously drawing away the fused material through said orifice in the form of filaments.

11. Apparatus as set forthin claim 3 in which said rams are parallel to each other within said chamber.

12. Apparatus as set forth in claim 2 in which said working faces apply said mechanical pressure directly to adjoining areas of said particles.

13. Apparatus as set forth in claim 1 in which said chamber is tapered inwardly toward the jet and the rams are tapered in the same direction as the chamber, the outer sides of the rams at those ends of the rams which are closest to said working faces being spaced from the adjacent walls of said tapered chamber, the construction and arrangement being such that, when a ram is moved away from said jet, particles of said material pass around that ram in the space between the outer sides of the ram and the walls of the chamber and into said layer.

14. Apparatus as set forth in claim 13 in which said rams are parallel and the inner sides of the rams at those ends of the rains which are closest to said working faces are in contact with one another.

15. Apparatus as set forthin claim 11, the outer sides of 'the rams at those ends of the rams which are closest to said working faces being spaced from the adjacent walls of said chamber, the construction and arrangement being such that, when a ramis moved away from said jet, particles of said material pass around that ram in the space between the outer sides of the ram and the walls of the chamber and into said layer.

16. Apparatus as set forth in claim 2, the outer sides of said rams at those ends of the rams which are closest to said working faces being spaced from the adjacent walls of said chamber, the construction and arrangement being such that, when a ram is moved away from jet, particles of said material pass around that ram in the space between the outer sides of the ram and the walls 'of the chamber and into said" layer.

17. Apparatus as set forth in claim 16 in which said 'walls are "tapered inwardly toward said jet and the inner sides of the rams at those ends of the rams which are closest to said working faces are in contact withione particles.

References Cited in the file of this patent UNITED STATES PATENTS McHen ch e Apr. 4, Billman Feb. 8, Weibel Feb.'13, Upton Nov. 3, Upton Nov. 3, Wienand Dec. 14, Lipscomb et a1 Apr. 10,

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