US3634576A - Spinneret unit and method for the spinning of chemical filaments - Google Patents

Spinneret unit and method for the spinning of chemical filaments Download PDF

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Publication number
US3634576A
US3634576A US810193A US3634576DA US3634576A US 3634576 A US3634576 A US 3634576A US 810193 A US810193 A US 810193A US 3634576D A US3634576D A US 3634576DA US 3634576 A US3634576 A US 3634576A
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United States
Prior art keywords
spinneret
filter
spinning
conduit
downstream
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Expired - Lifetime
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US810193A
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English (en)
Inventor
Rene Stuchlik
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Rhodiaceta SA
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Rhodiaceta SA
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Classifications

    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D4/00—Spinnerette packs; Cleaning thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/50—Details of extruders
    • B29C48/69—Filters or screens for the moulding material
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D1/00—Treatment of filament-forming or like material
    • D01D1/10—Filtering or de-aerating the spinning solution or melt
    • D01D1/106—Filtering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/05—Filamentary, e.g. strands
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/254—Sealing means
    • B29C48/2545—Sealing means for filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/50—Details of extruders
    • B29C48/69—Filters or screens for the moulding material
    • B29C48/693—Substantially flat filters mounted at the end of an extruder screw perpendicular to the feed axis

Definitions

  • the specification describes a spinneret unit for spinning textile filaments, in which the spinneret is mounted at the downstream end of the housing. Within the housing is mounted a first filter, having filter elements having a check threshold which decreases in the downstream direction. The flow rate is increased in a conduit of decreasing cross-section and the material then passes through a second filter located immediately upstream of the spinneret, the second filter having a check threshold no greater than any of the first filter elements.
  • the present invention relates to a spinneret unit and a method for the spinning of chemical filaments and also to a spinning process utilising the said spinneret unit.
  • spinneret unit is to be understood to mean as assembly which is connected to a feed for a material to be spun and which comprises filtering elements, the spinneret proper and elements providing for the flow of the material from the feed to the spinneret orifices.
  • a spinneret unit for spinning textile filaments comprising, a first filter having a plurality of filter elements each having a check threshold less than the filter element immediately upstream thereof, at least one conduit means downstream of the first filter element, the crosssection of said conduit available for ow being greater at the upstream end thereof than at the downstream end thereof, a second filter downstream of said conduit means, the check threshold of which is no greater than that of the most downstream of said filter elements of said first filter and a spinneret downstream of said second filter.
  • the invention further provides a method of spinning filaments from a thermoplastic material, such method comprising filtering the material progressively to retain impurities of increasing neness, increasing the flow velocity of the material, dividing the fiow into partial streams, the cross-section of which is no greater than that of the partial streams leaving the filter, and immediately thereafter, extruding the material through spinneret orifices.
  • spinneret unit according to the invention may be considered as comprising in combination:
  • (l) A first filter, the function of which it is to hold back the particles of foreign matter which might block or disturb the flow of the compound to be spun through the extrusion orifices.
  • the filter consists of filtering elements having a check threshold decreasing in the downstream direction. In proportion with the advance of the compound to be spun, through the filter, first of all the coarser impurities and then the finer impurities are retained by the various filtering elements.
  • the smallest check threshold utilised is, in practice, lower than 60 microns 3,634,575 Patented Jan. 11, 1972 lCe and ranges preferably between 25 and 40 microns.
  • the filtering element having the smallest check threshold of the filter is spaced slightly apart from the other filtering elements of the filter.
  • the elements constituting the filter may either be fabrics of textile or metallic material, wadding, non-woven webs, paper fabrics, layers of elements of predetermined grain size, optionally lagglomerated by sintering. If desired they may be supported by one or more permeable supports.
  • the selection of the above-mentioned elements depends not only on the check threshold which they exhibit but also on the conditions (for example temperature, pressure) under which the filtration is effected, these being conditions which may vary considerably, depending on the nature of the material to be spun.
  • At least one conduit for the compound to be spun the downstream end of which is smaller in section than its upstream end and, advantageously, less than a quarter of the section thereof.
  • the shape of the conduit between these two ends is, preferably, of a continuously decreasing nature, thus eliminating any dead zones on the path travelled by the material, and furthermore imparting progressive acceleration thereto. It has been found that a conduit of this kind in the spinneret unit substantially reduces mishaps or defects arising ⁇ during spinning, such as filament rupture, partial or even complete clogging of the spinning orifices, or poor uniformity in the count of the yarns.
  • This improvement is probably due to the effective reduction in the alterations undergone by the material during its travel through the unit according to the invention, whether what are concerned are physical alterations, for example an increase in viscosity going as far as the formation of gels, or, particularly in the case of spinning of melted polymers, chemical degradation resulting in an excessively long stay at a temperature near the fusion temperature.
  • the upstream end of the conduit is disposed near the downstream face of the first .filter and has the same cross-section available for flow.
  • the downstream end of the conduit is advantageously disposed near the filtering element arranged a short distance from the spinneret and consequently near the latter, and has a section corresponding substantially to the zone of perforation of the spinneret.
  • the conduit may be formed by one or more intermediate members. These members are advantageously constituted by a material which is a poor conductor of heat, so as to diminish non-uniformity of temperature at the level of the spinneret; it is furthermore advantageous that the said material should be slightly deformable, so as to avoid any leakage at the joints between adjacent elements.
  • the check threshold of the element of the second filter is preferably equal at most to 40 microns and advantageously smaller than 25 microns.
  • the filtering element may be composed of one or more layers of filtering materials, as mentioned above, the last layer, in the direction of progress of the material to be spun, being disposed a short distance from the upstream face of the spinneret, in practice advantageously at a distance ranging between a few tenths of a millimetre and 5 mm. It has been found that the arrangement of the second filter downstream of the conduit and a short distance from the upstream face of the spinneret improves the extrusion uniformity whilst at the same time substantially decreasing the pressure necessary for extrusion through extremely fine orifices.
  • the spinneret utilised may be of any suitable shape, for example it may be a plate or cup having a fiat or curved end face.
  • the spinning orifices are as close together as is possible, thus making it possible to reduce the section of the jet or stream of the material feeding the said orifices.
  • the latter are preferably disposed in one or more annular arrangements.
  • the distance between the orifices may be reduced if the latter are formed in a spinneret, the perforation zone of which has been made thinner a least in the vicinity of the orifices.
  • the material to be spun When material to be spun is introduced into the spinneret unit, the material is filtered and progressively freed from its impurities, commencing with the coarsest, and it is divided into an increasing number of part-hows of progressively finer section. The flow velocity of the compound as a whole is then increased and the flow is once again divided up into partial flows the section of which is at least as small as at the filtration outlet, and then, immediately after, the material to be spun is extruded through the spinning orifices. f.
  • This combination makes it possible to spin compositions using spinnerets which have finer oriices, and, in every case, substantially improves the spining uniformity and also the quality of the filaments or yarns obtained.
  • the present invention may be applied to the spinning of both artificial and synthetic filaments, obtained by extrusion of spinnable materials as a solution or in the melted state.
  • FIG. 1 is a longitudinal cross-section through a conventional form of spinneret unit
  • FIGS. 2 and 3 are views similar to FIG. 1 showing two.
  • FIG. 1 there is illustrated therein a conventional type of spinneret comprising a housing 22 to which is secured a spinneret 1 having a perforated zone in which perforations 20 are formed.
  • the housing 22 is threaded onto the outlet 2.1 of an extruder (not shown) and immediately below the lower end of the extruder are two bronze cloths 2 clamped together.
  • Six nylon fibre cloths 3 are fastened together below the bronze cloths 2, and a support grid 4 is placed thereunder.
  • a perforated plate S is located immediately below the support grid 4, and two further bronze cloths 6 are mounted immediately above a nylon fibre cloth 7 which is closely adjacent to the spinneret I1.
  • FIG. 2 A similar construction is illustrated in FIG. 2 except that this construction is formed according to the invention. It includes in series a cotton cloth 8, a support grid 4, two bronze cloths 2, six nylon cloths 3, a further support grid 4, a packing 9, a stainless steel cloth woven in a repp weave, commonly known as microrepp, this being secured to a further grid. Below this further grid is an intermediate frusto-conical conduit 11 and finally a second filter 12 mounted immediately above the orifices 20 in the spinneret 1, giving a space 13.
  • EXAMPLE 1 The two spinneret units illustrated in FIGS. 1 and 2 were formed, and a solution of cellulose acetate, having a combined acetic acid content of 55.5% was prepared at a concentration of 26% by weight in a solvent comprising 95 parts of acetone and 5 parts of water (by weight). This solution was extruded through each of the two spinneret units, the cup spinneret having a height of 7 mm. and being formed with 32 orifices 0.06 mm. in diameter, disposed annularly, the diameter of the annulus being 18 mm. and the distance between each orifice being 1.72 mm. between centres.
  • the bronze cloths 2 were at a spacing of four hundred wires per inch, the check threshold of the cloths being 40 microns.
  • the nylon cloths 3 had a check threshold of 25 microns, while the support grid 4 had 60 wires per inch, giving a threshold of 28 microns.
  • the perforated plate 5 had 3 mm. diameter apertures, the total free passage cross-section being 25% of the total area.
  • the bronze cloths 6 had wires at a spacing of 400 wires per inch, giving a check threshold of 40 microns, and the nylon cloth 7 had a check threshold of 25 microns.
  • the nylon cloths 7 were in contact with the spinneret 1. With -this type of ⁇ spinneret and the solution referred to above, the solution was spun at a temperature of 65 C., and a flow rate of 51.5 grams of solution per minute, corresponding to an extrusion velocity of 612 metres per min* ute. The pressure at the start of the spinning, measured upstream of the spinneret unit was 40 105 Pa. The filaments obtained were dried and wound on in a conventional manner, so as to produce a cellulose acetate yarn.
  • the cotton cloth 8 was a percal cloth having a check threshold of 8O microns.
  • the elements 2, 3 and 4 were as in the FIG. 1 construction, and the packing 9 had a thickness of 2 mm.
  • the stainless steel cloth 10, had a check threshold of 20 microns, and a No. 20 grid having a check threshold of approximately l mm. was used as the Isole mechanical support for the assembly.
  • the frusto-conical conduit 11, had a height of 7 mm., a larger diameter at the upstream end of 40 mm. and a smaller diameter of 20 mm. for the spinneret used.
  • the microrepp stainless steel second filter 12 had a check threshold of 15 microns. This was mounted directly, via a mounting ring, on the bottom of the spinneret providing a free space 13, the height of ywhich was equal to the thickness of the ring, i.e. 0.5 mm.
  • FIG. 3 A further construction according to the invention is illustrated in FIG. 3. This construction is similar to that of FIG. 2, except that instead of the conduit 11 the conduit was formed of polypropylene, the interior of which had the shape of a surface of revolution produced by rotating two semi-parabolas, so that the interior surfaces were generally convex.
  • the second filter 12 of FIG. 2 was replaced by a second lter 1.3, again of metallic microrepp which rested directly on the bottom 14 of the spinneret 1, a free space 18 being provided in a thinned down portion of the spinneret in which the spinning orifices 20 were formed.
  • Example l The conduit 16 had a height of 9 mm., its largest diameter being 41 mm., and its smallest diameter being 12 mm., corresponding to the thinned down circular zone 15 provided in the bottom of the spinneret.
  • the second filter 17 was identical with that of the filter 12 of Example 2, except that it did not have a support ring.
  • the solution to be spun was then extruded at a temperature of 65 C. and a fiow rate of 77 grams of solution per minute corresponding to an extrusion velocity of 918 mm. per minute, i.e. an increase of 52% relative to the conventional arrangement described in Example l using the FIG. 1 construction.
  • EXAMPLE 3 A solution of cellulose acetate having a combined acetic acid content of 55.5% was prepared having a concentration of by weight, in mixture of 97 parts of acetone .and 3 parts of water (by weight) and was extruded through a spinneret having 100 orifices, 0.025 mm. in diameter, and distributed as indicated below:
  • the solution to be spun was extruded at a temperature of 56 C., at a fiow rate of 11.1 g. of solution per minute, corresponding to an extrusion velocity of 245 m./min., so that it was possible to produce, in a conventional dry spinning cell, a 55 decitex/ 100 ply (i.e. 0.55 decitex per ply) yarn, at a velocity of 500 m./min., this being hitherto impossible to achieve.
  • the spinning stability was excellent, the yarn obtained being of good quality in every respect.
  • a spinneret unit for spinning textile filaments comprising, in combination:
  • thermoplastic material comprising the steps of:

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
US810193A 1968-03-25 1969-03-25 Spinneret unit and method for the spinning of chemical filaments Expired - Lifetime US3634576A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR145282 1968-03-25

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US (1) US3634576A (https=)
BE (1) BE730370A (https=)
BR (1) BR6907447D0 (https=)
DE (1) DE1915181A1 (https=)
FR (1) FR1582837A (https=)
GB (1) GB1209737A (https=)
LU (1) LU58262A1 (https=)
NL (1) NL6904084A (https=)
SU (1) SU388413A3 (https=)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3847524A (en) * 1971-09-24 1974-11-12 L Mott Spinnerette head assembly with porous metal filter and shear element
US4088431A (en) * 1974-05-07 1978-05-09 Imperial Chemical Industries Limited Melt spinning filter
US4340552A (en) * 1981-02-23 1982-07-20 Kling-Tecs, Inc. Melt spinning solution dyed filaments and improved spin pack therefor
US5254299A (en) * 1987-10-27 1993-10-19 The Dow Chemical Company Method of improving melt spinning of linear ethylene polymers
EP0911140A3 (de) * 1997-10-24 2001-10-17 GNEUSS KUNSTSTOFFTECHNIK GmbH Filterelement für Kunstoffschmelzen
CN104928766A (zh) * 2015-06-30 2015-09-23 南通醋酸纤维有限公司 含支撑台的喷丝帽
CN109183168A (zh) * 2018-08-30 2019-01-11 绍兴美纶化纤有限公司 涤纶纤维挤出成型装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2434828C3 (de) * 1974-07-19 1982-12-23 Spinnstoffabrik Zehlendorf Ag, 1000 Berlin Vorrichtung zum Filtrieren einer Flüssigkeit
DE102010019910A1 (de) * 2010-05-04 2011-11-10 Lüder Gerking Spinndüse zum Spinnen von Fäden, Spinnvorrichtung zum Spinnen von Fäden und Verfahren zum Spinnen von Fäden

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3847524A (en) * 1971-09-24 1974-11-12 L Mott Spinnerette head assembly with porous metal filter and shear element
US4088431A (en) * 1974-05-07 1978-05-09 Imperial Chemical Industries Limited Melt spinning filter
US4340552A (en) * 1981-02-23 1982-07-20 Kling-Tecs, Inc. Melt spinning solution dyed filaments and improved spin pack therefor
US5254299A (en) * 1987-10-27 1993-10-19 The Dow Chemical Company Method of improving melt spinning of linear ethylene polymers
EP0911140A3 (de) * 1997-10-24 2001-10-17 GNEUSS KUNSTSTOFFTECHNIK GmbH Filterelement für Kunstoffschmelzen
CN104928766A (zh) * 2015-06-30 2015-09-23 南通醋酸纤维有限公司 含支撑台的喷丝帽
CN109183168A (zh) * 2018-08-30 2019-01-11 绍兴美纶化纤有限公司 涤纶纤维挤出成型装置
CN109183168B (zh) * 2018-08-30 2021-06-08 绍兴美纶化纤有限公司 涤纶纤维挤出成型装置

Also Published As

Publication number Publication date
FR1582837A (https=) 1969-10-10
GB1209737A (en) 1970-10-21
NL6904084A (https=) 1969-09-29
LU58262A1 (https=) 1969-10-28
DE1915181A1 (de) 1969-10-16
BR6907447D0 (pt) 1973-03-29
SU388413A3 (https=) 1973-06-22
BE730370A (https=) 1969-09-24

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