US3570084A - Strand treatment - Google Patents

Strand treatment Download PDF

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US3570084A
US3570084A US815425A US3570084DA US3570084A US 3570084 A US3570084 A US 3570084A US 815425 A US815425 A US 815425A US 3570084D A US3570084D A US 3570084DA US 3570084 A US3570084 A US 3570084A
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strand
crimping
chamber
tension
successive
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Robert K Stanley
Malcolm F Irwin
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MALCOLM F IRWIN
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16JPISTONS; CYLINDERS; SEALINGS
    • F16J15/00Sealings
    • F16J15/02Sealings between relatively-stationary surfaces
    • F16J15/06Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
    • F16J15/10Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C67/00Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
    • DTEXTILES; PAPER
    • D02YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
    • D02GCRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
    • D02G1/00Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
    • D02G1/12Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics using stuffer boxes
    • DTEXTILES; PAPER
    • D02YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
    • D02GCRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
    • D02G1/00Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
    • D02G1/12Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics using stuffer boxes
    • D02G1/125Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics using stuffer boxes including means for monitoring or controlling yarn processing

Definitions

  • a primary object of the present invention is fixed-speed crimping of a textile strand in successive crimping steps.
  • Another object is multiple stutter-crimping of textile strands in successive crimping steps.
  • a further object is improved stabilization of crimp in crimped textile strands by application of successive crimping steps thereto.
  • FIG. 1 is a schematic representation of the processing of a textile strand through a first stutfer-crimping step according to the present invention
  • FIG. 2 is a front elevation, partly cut away, of component apparatus of the preceding view, with strand shown passing therethrough;
  • FIG. 3 is a side elevation of the apparatus and strand of FIG. 2;
  • FIG. 4 is a plan of the apparatus of FIGS. 2 and 3;
  • FIG. 5 is a schematic representation of a succeeding stuffer-crimping step according to this invention.
  • FIG. 6 is a front elevation, partly cut away, of component apparatus of the preceding view, with strand shown passing therethrough;
  • FIG. 7 is a side elevation of the apparatus and strand of FIG. 6;
  • FIG. 8 is a plan of the apparatus of FIGS. 5 and 7. 6
  • the objects of the present invention are accomplished, in successive crimping of a textile strand wherein the strand is withdrawn continuously at an essen tially constant rate from a first crimping zone and is fed continuously at an essentially constant rate into a succeeding crimping zone.
  • both such zones are stulfer-crimping zones. According thereto, additional tension is imposed on the strand between the withdrawal thereof from the first crimping zone and the entry thereof into the immediately succeeding crimping zone, such tension being essentially constant but adjustable.
  • FIG. 1 shows, schematically, strand 10 unwinding from conical package 11 to pass through guide 12 and successive pairs of rolls 13, 13' and 15, 15, with heater 14 for the strand intervening between the respective pairs of rolls.
  • Strand-traversing means 16 precedes pair of nip rolls 17, 17 which feed the strand into stufiing chamber 18, normally at a fixed or constant rate. Part of the chamber is cut away to reveal therein strand accumulation 10a, from which crimped strand designated as 10' is withdrawn longitudinally upward. After being withdrawn from the exit of the chamber and through tensioning means 19, the crimped strand is then denoted as 10", at least until reaching the next treating location.
  • the stufling chamber, feed rolls, and related stufiercrimping components are shown in greater detail, together with components of the tensioning means in subsequent views.
  • Drive means for the stuifer-crimper feed rolls are shown in some detail to aid understanding thereof. It will be understood that such drive means preferably include adjustable constant-speed electrical or mechanical devices, which may be and preferably are wholly conventional in design and, therefore, not shown. Nor is there any showing of drive means for the other rolls, both for the same reason of conventionality and also because some of them need not be driven at all, as is well known.
  • FIGS. 2, 3, and 4 show the indicated components and associated elements of the same apparatus in front and side elevation and plan, respectively.
  • Part of chamber 18 is cut away in FIG. 2. to reveal crimped strand 10 and accumulation 10a thereof in bore 28 of the chamber, which is shown in the shape of a square cylinder.
  • Strand 10 after passing between nip rolls 15, 15 passes through strand-traversing means 16 and into the nip of feed rolls 17, 17'. The latter rolls feed or stuff the strand into the entrance to the bore of the chamber, the front and rear walls of the chamber overlapping the front and rear faces of the rolls as far as the nip so as to ensure that all the strand enters the chamber.
  • the entering strand meets with resistance provided by the previously accumulated strand and buckles back and forth upon itself into a modified sawtooth or zigzag configuration or crimp.
  • the compact strand accumulation is forced along through the bore toward the exit therefrom.
  • Chamber 18 into which the strand is stuffed and in which it assumes crimped configuration, is supported on the front wall of frame 22, which has an inverted U-shape in side elevation.
  • Shafts 27, 27' for respective feed rolls 17, 17 are journaled in the front and rear walls of the frame and have intermeshing gears 37, 37 thereon behind the rear wall of the frame.
  • Shaft 27' also has pulley 29 thereon.
  • Motor 31 on the horizontal upper surface of the frame has shaft 32 on which is pulley 33.
  • Belt 34 interconnects pulleys 33 and 29 to transmit rotational force to the gears, shafts, and the feed rolls themselves. The direction of rotation is such as to feed or stuff the strand by and between the counter-rotating feed rolls into the entrance of the chamber.
  • the infeed rate is normally constant, although it may be adjustable to different rates to accommodate different strands or changes in operating conditions.
  • the exit end of the chamber bore located at the same level as the entrance in the embodiment shown in FIG. 1 and at a level vertically above the level of the entrance in the embodiment (which may be otherwise the same) shown in FIGS. 2, 3, and 4, is shown unobstructed, as is the rest of the bore.
  • Crimped strand denoted as is withdrawn at a constant or fixed rate, which may be adjustable if desired, from strand accumulation 10a inside and is passed through tensioning means 19, discussed in detail below. Thereafter the strand, then denoted as 10", is withdrawn to a succeeding crimping zone, also described hereinafter.
  • Tensioning means 19 comprises several rolls rotatably mounted on a supporting framework and means for retarding rotation of the rolls so as to superimpose tension on strand 10 passing thereover.
  • Framework 40 has at one side vertical flange 50 extending downward alongside stuffing chamber 18 and adjacent lateral extension 18a thereof to frame 22 to which it is affixed.
  • first roll 41 on axle 41a and third roll 43 on axle 43a are both contiguous with minor cylindrical portion 42 of second roll 42, which is mounted on axle 42a parallel to the other two axles. The first and third rolls do not touch one another.
  • Strand 10 passes about slightly less than half of each of the first and third rolls and about three-fourths of the minor portion of the second or intermediate roll, passing between the nip formed by each of the first and third rolls with the latter, after which the strand is denoted as 10".
  • Belt or strap 52 extends about a quadrant of the major portion of roll 12 from a fixed location on flange 50 at one end to stop 53 at the other end, upon which are supported weights 54, thereby biasing the belt or strap into frictional contact with the roll surface.
  • Strand 10' is pulled, as by the feed means of a succeeding stuffer crimper shown in subsequent views (or by forwarding rolls, etc.), in essentially non-slipping contact with first roll 41, minor portion 42' of the second roll, and third roll 43, thereby rotating them in the directions indicated by the arrows.
  • the major portion of roll 42 rotates in slipping frictional contact with belt or strap 52, which counters the positive rotation and thereby tensions the strand.
  • the tension can be increased by adding weights, and be reduced by subtracting weights, carried by the belt or strap.
  • Suitable tensions for nylon strands of about 2000 total denier and 140 filaments are on the order of tenths of a gram per denier, depending upon the desired degree of crimp, half a gram per denier often being a satisfactory value.
  • the resulting tension in the strand is essentially constant at a maximum value determined by the frictional contact just described, which tends to smooth out preexisting tension irregularities in the strand. As the control is passive, rather than active, it cannot superimpose additional tension variations upon the strand.
  • Adjustment is simplicity itself, and maintenance is practically nil.
  • Heater 14 optionally heats the strand to desirable crimping temperature (e.g., 150-350 F.), and the stuffing chamber may be heated as well, such as by a heating jacket or by resistance coils in the chamber wall (neither shown) to preclude cooling or excessive cooling of the strand in the chamber, although it normally will be at an appreciably lower temperature at the exit (e.g., about 120 F.) than at the entrance of the chamber.
  • Any suitable means may be used to preheat the strand, such as hot rolls, a bar type of heater, etc., instead of the illustrated heated chamber. Steam injection also may be used in either heater 14 or a preheating step.
  • the actual heater temperature will depend upon the degree of lubrication (if any) and rate of travel of the strand (1000-2000 yards or meters per minute is preferred) as Well as upon the strand composition and denier, the chamber composition, and the method of heating (conduction, convection, radiation, etc.).
  • the stuffing chamber and other apparatus elements may be made of steel or other durable material.
  • the inside wall of the chamber may be coated (e.g., with tetrafiuoroethylene) to reduce the coefiicient of friction, in which event the chamber should be lengthened accordingly.
  • a chamber length of about a yard or meter inner width about inch or a centimeter for use with strands of about 10 to denier has proved suitable for nylon and other commonly available textile strand materials, in an uncoated chamber.
  • the strand is withdrawn from the accumulation in the chamber at a constant rate and under tension sufficient to keep the furthest extent of the strand accumulation at some distance from the end of the cham ber, usually within the range of from about two-thirds to about nine-tenths of the infeed rate.
  • No means or method for synchronizing windup and feed rates is required, as the crimped strand will accumulate to a substantially constant level in the chamber, rising only slightly thereabove and falling only slightly therebelow, that level being determinable by setting the overall tension and, of course, by the physical characteristics of the strand, as well as the temperature, wall friction, etc.
  • Strand so crimped is free of undesirable irregularities attributable to uneven application of back-pressure by devices such as have been used in conventional stuffer-crimping apparatus or to uneven application of heat to the strand therein.
  • FIG. shows, schematically, further crimping of the strand whose crimping has been described above.
  • reference numerals for items similar or corresponding to items treated in the foregoing description of previous views are higher by one hundred, and with such indication in relationship specific mention of many thereof is superfluous and is omitted below.
  • Output strand from the apparatus previously described and illustrated becomes input strand 110 for the apparatus shown in FIGS. 5 to 8.
  • Heater 114 for the strand in advance of the entrance to this second crimping apparatus is optional and may be useful for maintaining isothermal conditions rather than permitting the strand to cool between crimping steps to a temperature less than the temperature prevailing during the crimping.
  • the entire region from the entrance to the previous crimper to the outlet from this crimper may be designed to meet the requirements for the intermediate zone of my US. Pat. 3,348,283, the conents of which are incorporated herein by reference insofar as pertinent.
  • Heater 114 preferably is of radiant electric, hot-air convective, or other dry type, to avoid introducing or to help dispel undesired moisture as too close to windup of the product, whereas previous heater 14 or an earlier preheater may utilize steam injection, as mentioned above.
  • the two successive crimping steps with illustrated tension control, especially therebetween, provide a well stabilized crimped textile strand having a lower potential shrinkage when subjected to further processing in conventional manner, thereby rectifying a feature (i.e., relatively high shrinkage potential) of once crimped textile strands sometimes criticized.
  • the resulting strands also are characterized by desirable distribution of crimp about the longitudinal strand axis, whereas a single stuffercrimping often produces a more planar crimp distribu tion instead.
  • the resulting moisture content is more even, especially where the strand was subjected to one or more steps of steam heating or liquid application (e.g., finish in emulsion or dispersion form).
  • the improvement com-prising crimping the strand in successive zones into and out of which the strand is fed and withdrawn at respective constant speeds, and controlling crimping back pressure by superimposing tension thereon at the strand is between the crimping zones.
  • Process comprising feeding a textile strand continuously at an essentially constant rate into a laterally confining region having an entrance and an exit, to accumulate temporarily therein in the form of a compressed strand accumulation being forced toward the exit by additional strand fed thereagainst at the entrance to the region, controlling crimping back pressure and, thus, the degree of crimping by withdrawing crimped strand from the accumulation thereof and out of the exit by application of forwarding tension thereto and superimposing additional tension on the strand between the locus of withdrawal thereof from the strand accumulation and the forwarding location, and feeding the strand into a like compressive crimping region at the forwarding location.
  • the improvement comprising reducing the shrinkage potential of the crimped product by utilizing at least principally friction of lateral confinement of the strand accumulation therein to apply crimping back-pressure to the strand entering the region, removing strand therefrom by withdrawing it from the leading edge of the strand accumulation, adjusting to a desired constant value the tension on the strand being withdrawn, including superimposing tension thereon in addition to the tension required to withdraw the strand therefrom, and thereby controlling the amount of strand accumulation and the accompanying crimping back pressure, forwarding the withdrawn strand at essentially constant forwarding rate greater than the withdrawal rate, and feeding the strand at essentially the forwarding rate directly to a succeeding stufier-crimping step.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Abstract

TEXTILE STRANDS ARE SUBJECTED TO SUCCESSIVE COMPRESSIVE CRIMPING STEPS, AS IN SUCCESSIVE STUFFER CRIMPERS, AT ESSENTIALLY CONSTANT, THOUGH DIFFERENT, INFEED AND WITHDRAWAL OR WINDUP RATES. CONTROL TENSION IS APPLIED BETWEEN SUCH SUCCESSIVE STEPS AND OPTIONALLY AFTER THE LAST SUCH STEP.

Description

March 16, 1971 R. K. STANLEY ETAL- 3,570,084
v STRAND TREATMENT Filed April 11, 1969 2 Sheets-Sheet l ROBERT K. STANLEY MALCOLM F. IRVHN March 16, 1971 R. K. STANLEY El'AL 3,570,084
STRAND TREATMENT Filed April 11, 1969 2 Sheets-Sheet 2 72,2 I O O l 7 I I J 27! //a V L i m mvmxu 1 1 ROBERT K. STANLEY MALCOLM F. IRWIN 7% w United States Patent Int. Cl. D02g 1/12 US. Cl. 28-7214 15 Claims ABSTRACT OF THE DISCLOSURE Textile strands are subjected to successive compressive crimping steps, as in successive stuffer crimpers, at essentially constant, though difierent, infeed and withdrawal or windup rates. Control tension is applied between such successive steps and optionally after the last such step.
This application is a continuation-in-part of my c0- pending application Ser. No. 688,119 filed Dec. 5, 1967 and now Pat. 3,500,518. Reference is also made to my US. Pats. 3,386,142 and 3,279,025 granted for related subject matter and the contents of which, insofar as pertinent hereto, are incorporated herein by reference.
It is conventional to crimp a textile strand compressively by feeding it by suitable means, such as between a pair of nip rolls, into the entrance of a temporarily confining region, in which the strand accumulates under pressure for some time before exiting therefrom and upon entering is compressed longitudinally to buckle into a modified zigzag or sawtooth crimped configuration. Multiple crimping of strands by application of successive crimping steps thereto is known but regardless of crimping method is complicated by apparent necessity for synchronization of the strand infeed rate and withdrawal or windup rate by varying such rate or rates.
A primary object of the present invention is fixed-speed crimping of a textile strand in successive crimping steps.
Another object is multiple stutter-crimping of textile strands in successive crimping steps.
A further object is improved stabilization of crimp in crimped textile strands by application of successive crimping steps thereto.
Other objects of this invention, together with means and methods for attaining the various objects, will be apparent from the following description and the accompanying diagrams.
FIG. 1 is a schematic representation of the processing of a textile strand through a first stutfer-crimping step according to the present invention;
FIG. 2 is a front elevation, partly cut away, of component apparatus of the preceding view, with strand shown passing therethrough;
FIG. 3 is a side elevation of the apparatus and strand of FIG. 2;
FIG. 4 is a plan of the apparatus of FIGS. 2 and 3;
FIG. 5 is a schematic representation of a succeeding stuffer-crimping step according to this invention;
FIG. 6 is a front elevation, partly cut away, of component apparatus of the preceding view, with strand shown passing therethrough;
FIG. 7 is a side elevation of the apparatus and strand of FIG. 6; and
FIG. 8 is a plan of the apparatus of FIGS. 5 and 7. 6
In general, the objects of the present invention are accomplished, in successive crimping of a textile strand wherein the strand is withdrawn continuously at an essen tially constant rate from a first crimping zone and is fed continuously at an essentially constant rate into a succeeding crimping zone. In a preferred embodiment of this invention, both such zones are stulfer-crimping zones. According thereto, additional tension is imposed on the strand between the withdrawal thereof from the first crimping zone and the entry thereof into the immediately succeeding crimping zone, such tension being essentially constant but adjustable.
Such added tension is used to control degree or extent of crimp at constant withdrawal and constant feed rates of the strand from one crimping zone to the next, which is astonishing because it would be expected that unless the withdrawal and feed rates were the same or at least were set at a particular fixed ratio to one another, the strand would either break or overflow between the successive crimping zones. It will be apparent that adjustment of the tension from one value to another is considerably simpler and more efficient than adjustment of either rate, and such control facility is a principal benefit of this invention.
FIG. 1 shows, schematically, strand 10 unwinding from conical package 11 to pass through guide 12 and successive pairs of rolls 13, 13' and 15, 15, with heater 14 for the strand intervening between the respective pairs of rolls. Strand-traversing means 16 precedes pair of nip rolls 17, 17 which feed the strand into stufiing chamber 18, normally at a fixed or constant rate. Part of the chamber is cut away to reveal therein strand accumulation 10a, from which crimped strand designated as 10' is withdrawn longitudinally upward. After being withdrawn from the exit of the chamber and through tensioning means 19, the crimped strand is then denoted as 10", at least until reaching the next treating location.
The stufling chamber, feed rolls, and related stufiercrimping components are shown in greater detail, together with components of the tensioning means in subsequent views. Drive means for the stuifer-crimper feed rolls are shown in some detail to aid understanding thereof. It will be understood that such drive means preferably include adjustable constant-speed electrical or mechanical devices, which may be and preferably are wholly conventional in design and, therefore, not shown. Nor is there any showing of drive means for the other rolls, both for the same reason of conventionality and also because some of them need not be driven at all, as is well known.
FIGS. 2, 3, and 4 show the indicated components and associated elements of the same apparatus in front and side elevation and plan, respectively. Part of chamber 18 is cut away in FIG. 2. to reveal crimped strand 10 and accumulation 10a thereof in bore 28 of the chamber, which is shown in the shape of a square cylinder. Strand 10 after passing between nip rolls 15, 15 passes through strand-traversing means 16 and into the nip of feed rolls 17, 17'. The latter rolls feed or stuff the strand into the entrance to the bore of the chamber, the front and rear walls of the chamber overlapping the front and rear faces of the rolls as far as the nip so as to ensure that all the strand enters the chamber. As the strand accumulates in the chamber, the entering strand meets with resistance provided by the previously accumulated strand and buckles back and forth upon itself into a modified sawtooth or zigzag configuration or crimp. As more strand is fed continuously into the chamber the compact strand accumulation is forced along through the bore toward the exit therefrom.
Chamber 18, into which the strand is stuffed and in which it assumes crimped configuration, is supported on the front wall of frame 22, which has an inverted U-shape in side elevation. Shafts 27, 27' for respective feed rolls 17, 17 are journaled in the front and rear walls of the frame and have intermeshing gears 37, 37 thereon behind the rear wall of the frame. Shaft 27' also has pulley 29 thereon. Motor 31 on the horizontal upper surface of the frame has shaft 32 on which is pulley 33. Belt 34 interconnects pulleys 33 and 29 to transmit rotational force to the gears, shafts, and the feed rolls themselves. The direction of rotation is such as to feed or stuff the strand by and between the counter-rotating feed rolls into the entrance of the chamber. As already indicated, the infeed rate is normally constant, although it may be adjustable to different rates to accommodate different strands or changes in operating conditions.
The exit end of the chamber bore, located at the same level as the entrance in the embodiment shown in FIG. 1 and at a level vertically above the level of the entrance in the embodiment (which may be otherwise the same) shown in FIGS. 2, 3, and 4, is shown unobstructed, as is the rest of the bore. Crimped strand denoted as is withdrawn at a constant or fixed rate, which may be adjustable if desired, from strand accumulation 10a inside and is passed through tensioning means 19, discussed in detail below. Thereafter the strand, then denoted as 10", is withdrawn to a succeeding crimping zone, also described hereinafter.
Tensioning means 19, a preferred embodiment of which is shown in detail in FIGS. 2 and 3, comprises several rolls rotatably mounted on a supporting framework and means for retarding rotation of the rolls so as to superimpose tension on strand 10 passing thereover. Framework 40 has at one side vertical flange 50 extending downward alongside stuffing chamber 18 and adjacent lateral extension 18a thereof to frame 22 to which it is affixed. Supported on the framework, first roll 41 on axle 41a and third roll 43 on axle 43a are both contiguous with minor cylindrical portion 42 of second roll 42, which is mounted on axle 42a parallel to the other two axles. The first and third rolls do not touch one another. Strand 10 passes about slightly less than half of each of the first and third rolls and about three-fourths of the minor portion of the second or intermediate roll, passing between the nip formed by each of the first and third rolls with the latter, after which the strand is denoted as 10". Belt or strap 52 extends about a quadrant of the major portion of roll 12 from a fixed location on flange 50 at one end to stop 53 at the other end, upon which are supported weights 54, thereby biasing the belt or strap into frictional contact with the roll surface.
Strand 10' is pulled, as by the feed means of a succeeding stuffer crimper shown in subsequent views (or by forwarding rolls, etc.), in essentially non-slipping contact with first roll 41, minor portion 42' of the second roll, and third roll 43, thereby rotating them in the directions indicated by the arrows. The major portion of roll 42 rotates in slipping frictional contact with belt or strap 52, which counters the positive rotation and thereby tensions the strand. The tension can be increased by adding weights, and be reduced by subtracting weights, carried by the belt or strap. Suitable tensions for nylon strands of about 2000 total denier and 140 filaments are on the order of tenths of a gram per denier, depending upon the desired degree of crimp, half a gram per denier often being a satisfactory value. The resulting tension in the strand is essentially constant at a maximum value determined by the frictional contact just described, which tends to smooth out preexisting tension irregularities in the strand. As the control is passive, rather than active, it cannot superimpose additional tension variations upon the strand.
Adjustment is simplicity itself, and maintenance is practically nil.
When the described stuffer crimper is being started up, it is desirable to insert a rod or the like in the open end of chamber 18 to compress the first bit of strand being fed therein until a wad of crimped strand has accumulated, after which the accumulated strand may be allowed to be forced further in the chamber from the entering end, accumulating additioinal strand in crimped configuration behind it. Contrary to prior practice, no added means is necessary to apply crimping back pressure to the strand during operation of the apparatus of this invention, although some could be used at or upstream from the furthermost downstream location of the compact accumulation of crimped strand, if desired, but predictably with less beneficial effect. Despite the lack of physical obstruction of the chamber the apparatus may be operated with the chamber in any desired orientation: e.g., horizontal as in FIG. 1, upright as in succeeding views, or at any intermediate angle, and even inverted (not shown).
Heater 14 optionally heats the strand to desirable crimping temperature (e.g., 150-350 F.), and the stuffing chamber may be heated as well, such as by a heating jacket or by resistance coils in the chamber wall (neither shown) to preclude cooling or excessive cooling of the strand in the chamber, although it normally will be at an appreciably lower temperature at the exit (e.g., about 120 F.) than at the entrance of the chamber. Any suitable means may be used to preheat the strand, such as hot rolls, a bar type of heater, etc., instead of the illustrated heated chamber. Steam injection also may be used in either heater 14 or a preheating step. The actual heater temperature will depend upon the degree of lubrication (if any) and rate of travel of the strand (1000-2000 yards or meters per minute is preferred) as Well as upon the strand composition and denier, the chamber composition, and the method of heating (conduction, convection, radiation, etc.). The stuffing chamber and other apparatus elements may be made of steel or other durable material. If desired, the inside wall of the chamber may be coated (e.g., with tetrafiuoroethylene) to reduce the coefiicient of friction, in which event the chamber should be lengthened accordingly. A chamber length of about a yard or meter (inner width about inch or a centimeter for use with strands of about 10 to denier) has proved suitable for nylon and other commonly available textile strand materials, in an uncoated chamber.
As described, the strand is withdrawn from the accumulation in the chamber at a constant rate and under tension sufficient to keep the furthest extent of the strand accumulation at some distance from the end of the cham ber, usually within the range of from about two-thirds to about nine-tenths of the infeed rate. No means or method for synchronizing windup and feed rates is required, as the crimped strand will accumulate to a substantially constant level in the chamber, rising only slightly thereabove and falling only slightly therebelow, that level being determinable by setting the overall tension and, of course, by the physical characteristics of the strand, as well as the temperature, wall friction, etc. Strand so crimped is free of undesirable irregularities attributable to uneven application of back-pressure by devices such as have been used in conventional stuffer-crimping apparatus or to uneven application of heat to the strand therein.
Preadjustment of the superimposed tension effects control of the degree or extent of crimp in the strand, the tension and the crimp varying in the same sense with respect to one another. Thus, a high tension produces an increased degree of crimp, together with a high level of strand in the chamber, as compared with a low level of strand and decreased crimp at a lower tension. Degree of crimp may be determined by any conventional method, and high crimp may be apparent in part as increased crimp frequency, reduced crimp leg length, reduced angle between adjacent legs, increased crimp retention under tension, or any combination of these with one another, or possibly other crimp characteristics.
FIG. shows, schematically, further crimping of the strand whose crimping has been described above. In this and succeeding views, reference numerals for items similar or corresponding to items treated in the foregoing description of previous views are higher by one hundred, and with such indication in relationship specific mention of many thereof is superfluous and is omitted below.
Output strand from the apparatus previously described and illustrated becomes input strand 110 for the apparatus shown in FIGS. 5 to 8. Heater 114 for the strand in advance of the entrance to this second crimping apparatus is optional and may be useful for maintaining isothermal conditions rather than permitting the strand to cool between crimping steps to a temperature less than the temperature prevailing during the crimping. In this respect the entire region from the entrance to the previous crimper to the outlet from this crimper may be designed to meet the requirements for the intermediate zone of my US. Pat. 3,348,283, the conents of which are incorporated herein by reference insofar as pertinent. Heater 114 preferably is of radiant electric, hot-air convective, or other dry type, to avoid introducing or to help dispel undesired moisture as too close to windup of the product, whereas previous heater 14 or an earlier preheater may utilize steam injection, as mentioned above.
Because of the crimp already imparted to the strand there is less reason for using means to traverse the strand with respect to feed rolls 117, 117' at the entrance to stuffing chamber 118, although some such traversing means may be employed if desired. In other respects the apparatus and procedure are relatively unchanged, but after passing through tensioning means 119 resulting strand 110" is shown as being wound onto cylindrical package 120 by grooved traversing drive roll 121. Alternatively the strand could be passed through another crimping zone of the same or a different sort, if desired.
The two successive crimping steps with illustrated tension control, especially therebetween, provide a well stabilized crimped textile strand having a lower potential shrinkage when subjected to further processing in conventional manner, thereby rectifying a feature (i.e., relatively high shrinkage potential) of once crimped textile strands sometimes criticized. The resulting strands also are characterized by desirable distribution of crimp about the longitudinal strand axis, whereas a single stuffercrimping often produces a more planar crimp distribu tion instead. The resulting moisture content is more even, especially where the strand was subjected to one or more steps of steam heating or liquid application (e.g., finish in emulsion or dispersion form).
While operation at essentially adiabatic, or at least constant-temperature, conditions throughout is preferred, it will be apparent that this invention readily permits either a high-temperature crimping step followed by an otherwise similar low-temperature crimping step, or vice versa, either of which may be desired for whatever reasons.
Although a preferred embodiment of this invention has been illustrated and described, by way of example, modifications may be made therein while retaining all or some of the advantages and benefits of the invention. Minor restriction or impedance of the strand in its path through the temporarily confining region, preferably in the vicinity of the feed rolls rather than further downstream, may be employed if desired. Parts may be added, combined, rearranged, or subdivided and equivalents be substituted without departing from the invention as defined in the following claims.
The claimed invention:
1. In crimping of a textile strand, the improvement com-prising crimping the strand in successive zones into and out of which the strand is fed and withdrawn at respective constant speeds, and controlling crimping back pressure by superimposing tension thereon at the strand is between the crimping zones.
2. The process improvement of claim 1, wherein the strand is stuffer-crimped in the successive zones.
3. The process improvement of claim 1, wherein the superimposed tension is adjustable and is preadjusted to an essentially constant rate value.
4. The process improvement of claim 3 wherein the degree of crimp varies in accordance with the superimposed tension, and including the step of preadjusting the superimposed tension to a constant value at which a preselected degree of crimp is obtained in the strand.
5. The process improvement of claim 1, wherein the strand is heated during its passage between the successive zones.
6. The process improvement of claim 5, wherein the strand is maintained at substantially constant temperature between the successive zones as in the first of the zones.
7. The process improvement of claim 6, wherein the temperature of the strand is maintained substantially constant throughout the successive zones.
8. Process comprising feeding a textile strand continuously at an essentially constant rate into a laterally confining region having an entrance and an exit, to accumulate temporarily therein in the form of a compressed strand accumulation being forced toward the exit by additional strand fed thereagainst at the entrance to the region, controlling crimping back pressure and, thus, the degree of crimping by withdrawing crimped strand from the accumulation thereof and out of the exit by application of forwarding tension thereto and superimposing additional tension on the strand between the locus of withdrawal thereof from the strand accumulation and the forwarding location, and feeding the strand into a like compressive crimping region at the forwarding location.
9. The process of claim 8, wherein the strand is preheated before being fed into the first laterally confining region to accumulate temporarily therein and is maintained at elevated temperature while in the confining region.
10. The process of claim 9, wherein the preheating comprises the step of applying steam to the strand.
11. The process of claim 10, wherein the strand is subjected to dry heating during its passage between the respective confining regions.
12. In stutter-crimping of a textile strand in a laterally confining region in which it accumulates temporarily under crimping compression, the improvement comprising reducing the shrinkage potential of the crimped product by utilizing at least principally friction of lateral confinement of the strand accumulation therein to apply crimping back-pressure to the strand entering the region, removing strand therefrom by withdrawing it from the leading edge of the strand accumulation, adjusting to a desired constant value the tension on the strand being withdrawn, including superimposing tension thereon in addition to the tension required to withdraw the strand therefrom, and thereby controlling the amount of strand accumulation and the accompanying crimping back pressure, forwarding the withdrawn strand at essentially constant forwarding rate greater than the withdrawal rate, and feeding the strand at essentially the forwarding rate directly to a succeeding stufier-crimping step.
13. The process improvement of claim 12, wherein essentially only the friction of lateral confinement of the strand is utilized to apply crimping back-pressure to the strand in the laterally confining region, the strand accumulation being unconfined ahead thereof.
14. The process improvement of claim 12, wherein the strand is withdrawn from the succeeding stuifer-crimping step and is wound up therefrom at a constant rate.
References Cited UNITED STATES PATENTS 1/1961 SWerdlOfi et a1 2872.14 4/1962 List et al. 28l.6
8 Ohashi et al 28l.6
Saito et a1. 287214 Stanley et a1 28l.6
Stanley 2872.14 Eskridge et a1. 2872.11
LOUIS K. RIMRODT, Primary Examiner
US815425A 1966-07-22 1969-04-11 Strand treatment Expired - Lifetime US3570084A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3831231A (en) * 1969-08-08 1974-08-27 Fiber Industries Inc Method for producing a yarn having latent bulking characteristics
US3955253A (en) * 1973-10-11 1976-05-11 Textured Yarn Co. Strand treatment apparatus
US20050044669A1 (en) * 2003-08-28 2005-03-03 Josef Wimmer Device and method for treating an elongated medium

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3499953A (en) * 1966-04-05 1970-03-10 Techniservice Corp Strand treatment
US3500518A (en) * 1967-12-05 1970-03-17 Techniservice Corp Strand treatment method and apparatus
US8046885B1 (en) * 2008-06-02 2011-11-01 Superba Apparatus and methods for crimping textile threads

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA679584A (en) * 1964-02-04 Iwnicki Kurt Crimping of yarn
US3046633A (en) * 1959-03-16 1962-07-31 Chori Co Ltd Apparatus for producing crimped thermoplastic synthetic yarns
US3279025A (en) * 1964-10-02 1966-10-18 Techniservice Corp Strand treatment process and apparatus

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3831231A (en) * 1969-08-08 1974-08-27 Fiber Industries Inc Method for producing a yarn having latent bulking characteristics
US3955253A (en) * 1973-10-11 1976-05-11 Textured Yarn Co. Strand treatment apparatus
US20050044669A1 (en) * 2003-08-28 2005-03-03 Josef Wimmer Device and method for treating an elongated medium
EP1512779A1 (en) * 2003-08-28 2005-03-09 Power-heat-set GmbH Device and process for treating an elongated medium
US7185406B2 (en) 2003-08-28 2007-03-06 Belmont Textile Machinery Company Device and method for treating an elongated medium

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GB1158488A (en) 1969-07-16
BE688059A (en) 1967-03-16

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