US 2964900 A
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Description (OCR text may contain errors)
Dec. 20, 1960 J. w. HICKS, JR 2,964,900
NOVELTY COMBINATION YARNS Filed Jan. 1'7, 1956 2 Sheets-Sheet 2 IN VEN TOR.
By W% 5% ATTORNEY JOHN WILBUR H|CKS,JR.
NOVELTY COMBINATION YARNS John Wilbur Hicks, Jr., Southbridge, Mass., assignor to Deering Milliken Research Corporation, Pendleton, S.C., a corporation of Delaware 5 Filed Jan. 11, 1956, Ser. No. 559,811
16 Claims. (cl. 57-140 This invention relates to improved yarns formed from a combination of filamentary and staple fiber materials, and is a continuation-in-partof US. application Serial Number 456,419, filed September 16, 1954, now Patent No. 2,825,199.
Most yarns used today can be classified either as spun 20 or as filament yarns. The spun yarns are generally employed for suitings, dress goods and the like and have the advantage of resulting in fabrics which have a high insulating value and which provide excellent cover. They have, as a general rule, the disadvantage of a relatively low tensile strength and in addition have disadvantages which are characteristic of the type of fiber or fibers employed in their formation. The filament yarns are generally employed in the manufacture of sheer hosiery or other sheer dress goods and have the primary advantage of a high tensile strength as compared to that of the spun yarns. They have the disadvantages of resulting in fabrics which provide poor cover and which have a low heat insulating value. For many years attempts have been made to combine staple fiber materials and filamentary materials to thereby obtain in a single yarn the advantages of both the spun yarns and the filament yarns but previous to this invention, such combination yarns have not been completely satisfactory in all respects.
An early efiort to prepare a combination yarn comprised simply plying together a spun yarn and a filamentary yarn but such yarns do not have the advantages which might be expected since the bulk of the spun yarn is reduced by plying with a filament yarn and since the resulting yarn results in a fabric with a harsh hand. In other words, many of the desirable qualities of spun yarns are due to their bulky nature and when the spun yarn is plied with a filamentary yarn, the staple material is compacted so that the resulting combination yarn does not provide'the insulation and cover that might be expected. Attempts have also been made to ply a pair of two-ply strands of the above type and thereafter slightly shrink the filamentary strands to result in a bulking of the staple fiber material but this has resulted in a yarn in which the filamentary strands carry the entire load so that the combination yarn is not as strong as might be desired.
A second effort to prepare a combination yarn having the advantages of both a spun and filamentary yarn comprised forming a sheath of staple fiber material around a filamentary core but the disadvantages of core yarns are now well known. Staple fiber material, wrapped around a core of smooth filaments, tends to slide on the core and this causes difficulties during various processing operations. For example, if one attempts to pass the yarn through a guide or the like, the fiber material collects on the entry side of the guide and one obtains a condition known as skin back. A further disadvantage is that in a core yarn, the stress is carried primarily by the core and the surface wrapping of fibers does not contribute appreciably to the tensile strength of the yarn. Attempts have also been made to ply two core yarns to posite yarn comprised spinning a plurality of synthetic ice thereby eliminate the tendency for the staple fibers to slide on the smooth core but this necessitates an additional fabricating step, limits the minimum size of the yarn that can be produced and 'even with a plied yarn of this type the core yarns still carry most of the stresses and the staple material does not contribute its share to the overall strength of the yarn.
A more recent attempt to fabricate a satisfactory comfilaments into a bath containing very short length staple material (U.S. Patent 2,053,123). Thisprocedure results in a yarn or cord which may be excellent for certain applications, such as in the manufacture of tires, but yarns produced in this manner are not generally satisfactory for wearing apparel because the short fiber material is not placed generally parallel to the filamentary strands but rather extends at sharp angles from the surface of the yarn or thread. This results in a very scratchy yarn that would be extremely uncomfortable if formed into a cloth to be worn adjacent to the human body. Still another disadvantage is that the short fiber material does not contribute to the overall strength of the yarn so that the strength to weight ratio of the yarn is not as high as might be desired.
It is a primary object of this invention to provide a combination yarn, formed in part from staple material 9 and in part from filament material, which'overcomes the disadvantages of prior art combination yarns.
According to this invention there is provided yarn, suitable for use in the manufacture of apparel fabrics, composed of a plurality of generally parallel continuous filaments twisted together with staple fiber material. The staple fibers are generally aligned withv the continuous filaments but are sufiiciently entwined among the continuous filaments to prevent extensive movement of the staple fiber material along the longitudinal. axis of the yarn and are ,sufliciently entangled to result in the fiber material contributing substantially to the strength of the yarn. The novel yarns of this invention provide excellent cover and heat insulation since the staple fiber material is not highly compacted by the filamentary strands. cellent hand since the staple fibers are generally aligned with the longitudinal axis of the yarn and since the filamentary strands are generally parallel to each other and do not cross at sharp angles. Theyarn can readily New yarns according to this invention wherein the' fibrous material is evenly distributed along the length of the filamentary strand have many advantages and can generally be employed for any application where spun yarns are conventionally utilized. It is believed that the potentalities of the new yarns can best be illustrated by comparing a yarn according to this invention comprising continuous strands of polyester filaments and wool fibers, with a conventional spun yarn composed of a mixture of wool and polyester staple fibers. Blends of wool fibers and polyester fibers have been enthusiastically received because of the excellent crease and shape retention of fabrics woven therefrom and because of their superior strength as compared to woolens. However, fabrics woven from such yarns, due to the presence of polyester fibers, tend to pill badly and to collect static electrical charges. Yarns prepared according to this invention from polyester filaments and wool fibers, when woven into cloth, do not pill because the polyester material is present only in the form of embedded filaments rather than in the form of exposed surface fibers,
The new yarns result in fabrics having an ex- 3 2 nor do they collect static electricity to the same extent as fabrics woven from spun blends of polyester fibers since when a fabric woven from the new yarns of this invention is brought into contact with another surface or with itself, the contact is almost entirely limited to the wool fibers which extend from the embedded polyester filaments. In addition, fabrics woven from yarns accord ing to this invention display substantially the same crease retention and wrinkle resistance as do fabrics woven from conventional blends and display increased dimensional stability because the wool fibers are locked in position by the polyester filaments and cannot migrate. Fabrics woven from the new yarns are also characterized by greater strength because the polyester component of the yarnis present in the form of filaments rather than in the form of staple fibers.
In view of the above comparison, it will be seen that the components of the new yarns of this invention can be selected to result in fabrics having the advantages desired in any particular instance. For example, fabrics can be woven having the appearance: of cotton and substantially the strength of nylon by employing yarns according to this invention composed of nylon filaments and cotton fibers. In addition, the fabric will have a lower water absorption, better crease retention, and increased dimensional stability. The new yarns of this invention result in more satisfactory fabrics, even when the fibers and filaments are of the same chemical composition, than do yarns containing 100% staple fiber material. For example, a fabric woven of 100% polyester material according to this invention generally displays a decreased tendency to pill, as compared to a fabric formed from spun polyester yarns, and in addition is characterized by greater strength beacuse of the presence of filamentary strands.
If desired, yarns according to this invention can be formed with the fibrous material collected into distinct assemblages or slubs and such yarns have numerous advantages over similar prior art yarns. For example, slub yarns according to this invention can readily be produced in a very wide range'of deniers and with many difierent styles and sizes of slubs and the resulting yarns in each instance have a very high weight to weight ratio. In addition, by a suitable choice of materials, it is possible to produce yarns wherein the filaments and the fiber material are substantive to entirely different types of dyestulfs so that one can readily prepare fabrics wherein the slubs have a contrasting color as compared to the body of the fabric.
The new yarns of this invention are preferably prepared by bringing together a drafted ribbon or the like or fibrous material and a ribbon of separated filaments and thereafter twisting the two together into a unitary strand. The ribbon or fibrous material can readily be prepared by passing sliver or roving between a plurality of pairs of drafting rollers rotating at difierent peripheral velocities, such as is done in the conventional spinning of staple fiber yarns. The filamentary ribbon can be formed by separating the component filaments of a multifilament yarn, having little or no twist, for example, by imparting a static charge to the filaments so that they repel each other and thereafter placing the yarn under avery low tension so that the filaments are free to separate. The ribbon of drawn fibers and the ribbon of filamentary material are best brought together by passing the two in superimposed relationship between a pair of driven rolls, such as illustrated by the delivery rolls of a drafting frame. The two ribbons are then twisted together, at the point where they are delivered from between the driven rolls, by any suitable conventional means such as, for example, a ring and traveller spinning array.
The invention will now be more specifically described with reference to the accompanying drawings in which:
Figure 1 is a schematic view in perspective, with principal parts and location, of apparatus suitable for manufacturing the novel yarns of this invention,
Figure 2 is a cross sectional view along the line 2,2
of Figure l.
Figure 3 is an enlarged elevational representation of a composite yarn according to this invention.
Figure 4 is a cross sectional view of an end of the new yarn which has been compacted for purposes of sectionmg.
Figure 5 is an elevational representation of a slubbed yarn according to this invention.
With reference to Figures 1 and 2 of the drawings, the reference numeral 10 indicates a yarn supply package such as a cone, hank, cop or the like, of multi-filament yarn of a type capable of being given a static charge. A pigtail guide, indicated by the reference numeral 12, is positioned over the yarn supply package 10 so that a yarn end or, strand 13 may be readily unwound therefrom and immediately below the guide 12 is a tension array, indicated by the reference numeral 14, comprising a pair of disk tension devices between which the strand 13 is adapted to be passed so that it can be placed under tension in the section of the yarn path immediately .duit 18 and thereafter through a number of short tubes one of which is indicated by the reference numeral 20 and illustrated as being positioned in the path of the yarn end 13. The fan 16 is adapted to be driven by any suitable means such as electric motor 22 which is connected by suitable electrical conductors 24 to a supply of electric power. So that the air distributed by header 18 will be at higher than room temperature and thereby capable of exerting a greater drying effect, a section 26 of the conduit connecting fan 16 with header 18 is preferably provided with heating elements such as the resistance elements indicated by the reference numeral 28. The resistance elements 28 are connected to a suitable power supply by electrical conductors indicated by the reference numeral 30. A single switch 32 can be employed for operation of both the electric motor 22 and the heating elements 28.
The tube 20 is illustrated as being positioned in the yarn path immediately below and forwardly of tension array 14 and is adapted to receive yarn end 13 through an orifice 34 in header 18. To avoid the use of a threading tool, tube 20 and header 18 may be provided with a narrow slit as indicated at 36 so that the yarn end may simply be pulled into its proper flow-path.
There is generally indicated by the reference numeral .38 an electrifying assembly for imparting a static charge to the multi-filament yarn. The assembly 38 comprises a shaft 40 which is adapted to be rapidly rotated by any suitable means such as an electric motor 42. Inset in a suitable groove in shaft 40 and extending longitudinally along a portion of its length is a rubbing element or blade 44 adapted to frictionally contact the yarn end 13 and impart a static charge thereto. Blade 44 is preferably of a material widely separated from the composition of strand 13 in the triboelectric series so that it can more effectively impart a static charge to the filimentary strand.
So that the multi-filament yarn 13 will be contacted by the blade 44 only when desired, there is preferably provided a movable arcuate shield indicated by the reference numeral 46. The arcuate shield 46 is mounted for rotation about the axis of shaft 40 so that it may be pivoted to a position such that it will hold the yarn end 13 out of contact with blade 44 or to a position such that it will be completely out of contact with the yarn end as is clearly illustrated in Figure 2.
Positioned rearwardly of assembly 38 is a three-element drafting frame, generally indicated by the reference nu-. meral 48, having a back roll pair 50, an intermediate roll pair 52 and a delivery roll pair 54. The drafting frame 48 may be and preferably is of the type generally found on a conventional spinning frame except that in this instance, the delivery roll pair is driven independently of the other elements of the drafting frame. Means for driving the delivery roll pair 54 is illustrated as comprising a shaft 56 and an electric motor 581 The electric motor is illustrated as directly driving shaft 56 but it will be appreciated that Figure 1 is only schematic and that an appropriate gear train for reducing the rate of rotation of delivery rolls 54 to a suitable value should be provided. Electric motors 58 and 42 may be connected in parallel through electrical conductors 60 and 62 and operated through a single switch 64 since it is generally desirable that the two motors be in operation at all times when the apparatus is being utilized.
The back and intermediate roll pairs 50 and 52 of drafting frame 48 are adapted to be employed for either the insertion of a slub of fibers into the multi-filament strand 13 or for the feeding of a continuous supply of fibrous material to the strand 13 as it is led from the assembly 38 over the top roll of roll pair 54 and back between the two rolls. The fibrous material is preferably supplied in the form of staple sliver or roving, a suitable supply of which is indicated by the reference numeral 66 in the form of a bobbin, cop or the like. An end 68 from supply 66 is illustrated in the drawings as being fed between the back roll pair 50 of drafting frame 48 and from this point it travels to the intermediate roll pair 52 in a conventional manner.
A separate means must be provided for driving the back two roll pairs of the drafting frame 48 since in the prw duction of slubbed yarns the operation of these elements must be intermittent and in Figure l the driving means is illustrated as comprising a rotatable shaft 70 extending from back roll pair 50 to an electric motor 72. It will again be understood that. although the connection in Figure 1 of the drawings is illustrated as being direct. suitable reduction gears should be provided so that roll pair 50 is driven at an appropriate speed. Roll pair 52 is driven from shaft 70 by means of gear 74, idler gear 76, gear 78 and shaft 80. As in conventional operation, the roll pair 52 should be driven at a higher rate of speed than roll pair 50 so that there is drafting of the strand 68 between the two roll pairs.
Located forwardly of drafting frame 48 is a pigtail guide 82 which is adapted to receive the yarn end 13 following its departure from roll pair 54. Positioned immedi tely below the guide 82 is a conventional spinning or twisting spindle array generally indicated by the reference numeral 84 and comprising a spindle 86 over which there is placed a bobbin 88 adapted to collect a supply of yarn 90. A conventional spinning ring 92 with a rotating traveller 94 also constitutes a part of the array 84. The spindle 86 is adapted to be driven in a conventional manner by contact of a whorl section 96 with a belt 97 running about a pulley 98 which is illustrated as being driven by motor 58 through a gear 99 on shaft 56, gears 100 and 101 on shaft 102, gears 103 and 104 on shaft 105 and a gear 106 on a shaft 107 carrying pulley 98. It should be clear, however that it is not intended that the drawing necessarily illustrate the actual gear arrangement for driving spindle array 84 but only that front roll pair 54 of drafting frame 48 and the spinning array 84 can be and preferably are driven by a common power source.
The reference numeral 108 indicates a source of elec trical impulses, preferably random in frequency, and can suitably be a device of the type described in US. Patent No. 2,622,282, or any other arrangement for supplying pulses of electrical energy of controlled duration. The pulses from source 108 are fed in one instance through conductors 110 to a solenoid 112 with a core 114 of conventional design and construction. The core 114 is connected through a flexible strand or cord 116 to a spring member 118 having one end secured to a suitable support. The flexible cord 116 between core l14-andspring 118 is wrapped one or more turns about a cylindrical member 120 which is positioned on the extendedaxis of rotation of shaft 40 and operatively connected through an arm 122 to shield 46. The cord 116 is ofsuch length that spring means 118 normally retains core 114 partially removed from solenoid 112 when the solenoid is not energized and the positional relationship of member 120 to strand 116 is such that when the solenoid 112 is not energized, shield 46 is in a position such that contact of strand 13 with blade 44 is prevented. When solenoid 112 is energized, core 114 is moved against the bias of" spring 118 thereby rotating shield 46 to permit contact of the strand 13 with the blade member 44.
The electrical pulses from source 108 are also transmitted'through a conductor 124 to an electric time delay device indicated by the reference numeral 126. Electric time delay devices suitable for this purpose are commercially available from several sources and excellent results have been obtained with a General Electric Electronic Time Delay Relay. The device is adapted to be activated by the impulse received through conductors 124 and a selected time later, suflicient to allow passage of a point on strand 13 from assembly 38 to the delivery roll pair 54 of drafting frame 48, to send an electrical impulse through conductors 128 to motor 72. The electronic time delay device is preferably so adjusted that the delayed im-. pulse sent to motor 72 terminates simultaneously with the impulse sent to solenoid 112 through conductors 110.
From what has beensaid it will be apparent that apparatus such as described can be constructed from a conventional spinning frame by simply adding the assembly 38, the strand drying arrangement comprising fan 16 and header 18, and tension array 14. The spinning frame need then only be modified by disconnecting the back two roll pairs of the drafting frame, with which the spinning frame is provided, from their conventional driving means while allowing the front roll pair to continue to be driven in a conventional manner by the motor which drives the spinning spindle. A separate motor activated through a source of electrical impulses and an electronic time delay is then provided for driving the back elements of the drafting frame. The apparatus can similarly be constructed from a conventional twisting frame except that in this instance it is necessary to provide the frame with drafting rolls.
For the production of slubbed yarns, a strand from package 10 is threaded through guide 12, tension array 14, and then is pulled through slit 36 into tube 20. The yarn end is then passed around assembly 38, over and between the delivery roll pair 54 of drafting frame 48 and thereafter through guide 82 to the spindle array 84. A second strand preferably formed from staple fiber materials is led from package 66 between the back roll pair 50 and center roll pair 52 of drafting frame 48. The apparatus is now ready for operation and switch 32 can be thrown to place the fan 16 in operation and heat the resistance elements 28. After a few moments to allow the resistance elements-to become heated and the segment of strand 13 in tube 20 to become thoroughly dried, switch 64 can be thrown, to place motors 58 and 42 in operation, and the source of electrical impulses 108 can be energized to intermittently supply a flow of current to motor 72 and solenoid 112.
When source 108 produces an electrical impulse it is transmitted simultaneously to solenoid 112 and electronic time delay 126. Immediately core 114 is drawn downwardly so that member 120 is rotated to remove shield 46 to an inactive position so that strand 13 is contacted by rapidly rotating blade 44. The contact between blade 44 and strand 13 results in the filaments of strand 13 in each instance acquiring a like charge so that they exhibit a 7 mutual repulsion of each other and tend to become as greatly separated as possible.
Blade 44 and shaft 40 also contribute to the successful operation of the new apparatus in several other respects. In the first place, the blade rotating in a direction opposed to the forward movement of the strand 13, tends to hold back the twist and also to exert a ribboning effect so that the filaments of strand 13 are encouraged to enter the bite of delivery rolls 54 in spaced parallel relationship. In addition, the eccentric protrusion of blade 44 from shaft 40 acts to alternately tension and relax end 13. The periods of relaxation permit the filaments of strand 13 to become separated to a maximum extent not possible with the strand under continuous tension, while the periods of tension make possible adequate frictional contact of strand 13 with blade 44.
A preselected time after the impulse produced by source 108 reaches time delay 126. the impulse is transmitted to motor 72 which places in operation the back two elements of drafting frame 48. The rotation of these rolls feeds strand 68 to the bite of roll pair 54 where it is pressed inso contact with the separated filaments of strand 13 and becomes entwined among the filaments of the strand as it departs delivery rolls 54 and is twisted by spindle array 84. Inasmuch as the rolls in pair 52 are rotating at a higher rate than the rolls in roll pair 50, it will be seen that strand 68 is drafted so that the fibers therein are spread and ribboned in a conventional manner. If desired, roll pair 54 can be operated at a higher rate than either of the back elements of the drafting frame so that further drafting and ribboning is obtained between roll pair 52 and roll pair 54. The drafting and ribboning of strand 68 during its passage through drafting frame 48 is important since this permits a smoother blending of the fibers into strand 13 and permits the fibers to become more thoroughly ensnared between the individual filaments of strand 13 as it departs delivery rolls 54 and is twisted by spindle array 84.
After a suitable preselected interval of time the electrical impulse furnished by source 108 is terminated. One result of the termination of the impulse from source 108 is that core 114 is drawn upwardly from solenoid 112 by the resiliency of spring 118 which in turn results in the rotation of member 120 and thepositioning of shield 46 so that strand 13 is no longer in contact with blade 44. This allows any twist which has accumulated above assembly 38 to pass and thereafter become evenly distributed in strand 13 in its journey to spinning array 84. The termination of the impulse from source 108 also results in the de-energization of motor 72 and the inactivation of roll pair 50 and roll pair 52. Since roll pair 54 continues to operate, strand 68 is ruptured between roll pair 54 and roll pair 52 and the trailing end is bound into strand 13. This completes the cycle and the apparatus continues to function only as a twisting frame until at some future time another electrical impulse is provided by source 108.
For the production of yarns having staple length fibers distributed evenly along the length of the filamentary strand, the apparatus illustrated in Figures 1 and 2 of the drawings is operated exactly as described above except that the source of electrical impulses 108 and the electronic time delay 126 are set or shunted to provide a continuous supply of energy to the solenoid 112 and to motor '72. Continuous operation of the motor 72 results in the back elements of drafting frame 48 feeding an even and continuous supply of staple fibers to be entwisted in strand 13 while continuous energization of solenoid 112 results in shield 46 being retained in an inoperative position at all times so that strand 13 is uniformly electrified as it is fed to the delivery rolls 54 of drafting frame 48.
With specific reference to Figure 3 of the drawings, there is pictured an elevational representation of a composite yarn formed from polyester (Dacron) filaments and from wool fibers, indicated by the reference numeral 132 and distinguishable by reason of their being more heavily shaded. It willbe understood that it is substantially impossible to accurately portray in a two dimensional drawing, an involved, three dimensional subject such as the yarn of this invention, and also, that one segment of a yarn according to the invention differs greatly in appearance even from an adjacent segment of the same yarn. The drawing does, however, illustrate several features of composite yarns according to this invention.
From Figure 3 of the drawings it will first be seen that the staple fibers are relatively great in length as compared to the diameter of the yarn, and the average length of the fibers should be at least about 25 and preferably at least 50 times the mean diameter of yarn. It will be understood that the processes for making yarns according to this invention need not result in any appreciable change in the staple length of the staple fiber material initially employed and that the length of the staple fiber material in the finished product is a characteristic of the specific staple fiber material initially employed. It will also be seen that the polyester filaments are generally parallel to each other, that the staple fibers are generally aligned with the continuous filaments, and that there are few if any short ends protruding at sharp angles to the longitudinal axis of the yarn. Because of these features, the yarns of this invention result in fabrics having an exceedingly desirable hand. It will further be seen that in spite of the general alignment of fibers and filaments, there is considerable random intermixing and interweaving of the fibers between and among the filaments and considerable tangling of the fibers with themselves. Because of this, the fibers as a mass, are locked against appreciable longitudinal movement along the longitudinal axis of the yarn and contribute appreciably to the strengthof the yarn. It will further be seen that the filaments do not highly compact the fibers and for this reason the yarn has a high heat insulating value and provides an excellent degree of cover.
Figure 4 of the drawings is a cross sectional view of a wool-polyester yarn and illustrates the intermixing of the wool fibers 134 with the polyester filaments 136. While it was necessary to compact the yarn for purposes of sectioning, when the yarn is in its normal state the crimp in the wool fibers, in instances where they lie between a plurality of filaments, separates the filaments and adds to the bulk of the yarn.
Figure 5 of the drawings illustrates a slubbcd yarn according to this invention with distinct assemblages of fibers 138 and 140 entwined between a plurality of filaments indicated by the reference numeral 142. This illustration has been drawn on an enlarged scale, in a direction perpendicular to the longitudinal axis of the yarn, for purposes of clarity but has been drawn on a reduced scale along the longitudinal axis of the yarn because of space limitations, and it will be understood that the slubs are generally considerably longer in length than illustrated.
The filamentary component of the novel yarns of this invention can comprise natural fibers, such as silk, as well as synthetics such as viscose rayon, acetate, rayon, nylon, polyester filaments such as those formed from a product produced by the reaction of terephthalic acid and ethylene glycol and sold under the trademark Dacron, acrylic fibers such as those formed from a product produced by the polymerization of acrylonitrile or by the copolymerization of acrylonitrile and a minor amount of another polymerizable monomer and sold under the trademarks of Orlon and Acrilan, or any other type of filamentary material commercially available. For special applications, glass or metal filaments may even be employed. Likewise, the staple fiber material may be of natural origin and may comprise cotton, wool or flax, or it may be of synthetic origin. For example, staple fibers example, if one desires a fabric similar to conventional cotton fabrics but having greater strength and crease resistance, one can employ cotton fibers in combination with polyester or nylon filaments. Likewise, if one desires a fabric having an appearance and utility similar to that of conventional woolens one can employ a mixture of wool fibers and polyester or acrylic filaments.
The length of the fibers in the fibrous material is an important consideration since if the mean length of the fibers is too short, a ribbon of the same cannot readily be formed by drawing and, in addition, the resulting composite yarn may have a marked tendency to shed or lose the staple material. As a general rule, fibrous material having an average length of at least about A inch should be utilized and the average length of the fibers is preferably at least about A of an inch. There is no upper limit as to the length of the fibrous material employed except that in the manufacture of slub yarns, the average length of the fibers should be somewhat less than the length of the shortest slub desired. For example, if the shortest slub desired has a length of about one inch, fibrous material having an average length greater than this would result in a slub longer than desired and, in addtion. the end of the slub might not be well bound into the filamentary yarn. Even when the fibrous material is to be distributed continuously along the length of the filamentary strand, it is not generally advant geous to employ fibrous material having an average length reater than about 3 to 6 inches since longer lengt s of staple material may result in yarns devoid, to some extent, of an appearance characteristic of spun yarns.
While it is only necess ry that the new yarns of this invent on contain a plurality of fiaments between which the staple fiber material is entwined, the filamentary strand from which the yarns are prepared should preferably contain at least about five to ten filaments since if the number of filaments is below this figure, the staple material may not be adequately secured in position. Another advantage of employing fi amentary strands containing at least about to 10 filaments is that they are more readily available and generally are less expensive than strands with a smaller number of filaments. There is no upper limit as to the number of filaments that the filamentary strand may contain except that imposed by availability.
In some instances two readily available strands of lower denier than desired may be run together to give a single strand and thereby increase the total number to 80 percent by weight of the yarn: The appearance of yarn according to this invention wherein the staple fiber material is evenly distributed and wherein the staple constitutes about 40% or more of the total weight,
of filaments and, in fact, this procedure has the additional advantage, for preparing yarns with staple distributed as evenly and as continuously as possible along the length thereof, that any turns of incidental twist originally present in one of the lower denier strands or twist resulting from the strand being withdrawn from the package, will generally not coincide with the incidental twist in the second lower denier strand so that it is possible to prepare a more uniform yarn.
The ratio of fibrous material to filamentary material may vary within wide limits and depends to some extent upon the intended use of the yarn. If one is not interested in producing yarns which have the general appearance of spun yarns and is interested only in obtaining a novel appearance such as can be obtained with siubbed yarns, the percentage of fibrous material may be as low as a fraction of one percent, but if it is desired that the yarn have the general appearance of a spun yarn, best results are generally obtained from combinations wherein the staple fibers constitute from about 30 is'almost identical to that of a spun yarn except that it is generally more uniform and the long fiber protrusion or fuzziness is generally somewhatless. In most instances it is not advantageous to employ the staple material in percentages greater than about 80% since this requires the insertion of a greater amount of twist and since the yarns begin to lose some of the advantageous characteristics imparted by the filamentary strands. There are exceptions, however, and one instance when it may be desirable to exceed this figure is in the preparation of yarns for very light weight summer materials wherein the filamentary material, even though present in very small percentages, can serve to increase appreciably the minimum breaking strength. This makes possible the production of extremely light weight fabrics and one can, for example, weave a fabric which approximates in appearances and strength a good tropical woolen but which has only about one-half the weight.
The amount of twist that should be inserted in the filamentary strand, following its contact with a suitable source of staple fibers, to adequately secure the fibrous material in position, should be at least about 5 turns per inch and preferably at least about 10 turns per inch. This additional twist forces the filaments of the strand together, even though they might still retain the remnants of the static charge earlier imparted, and thus secures the fibers firmly in position so that they are not readily dislodged. There is no upper limit as to the amount of twist that can be inserted, as far as the operativeness of the new process is concerned, since the greater the amount of twist, the more rigid the securement of the fibers; however, excessive twist in the new yarns of this invention will, as in any other yarn, result in bad handling characteristics.
Having thus described my invention, what I desire to claim and secure by Letters Patent is:
l. Yarn, suitable for use in the formation of apparel fabrics, composed of a plurality of generally parallel continuous filaments twisted together with staple fiber' material, the staple fibers being generally aligned with said continuous filaments but being entwined among said continuous filaments such that extensive movement of said staple fiber material along the longitudinal axis of said yarn is prevented as a result of such entwinement, and being sufiiciently entangled to substantially contribute, at least locally, to the strength of said yarn.
2. Yarn according to claim 1' having staple fiber material continuously distributed along the length thereof to thereby result in a strand having the appearance of a spun yarn.
3. Yarn according to claim 1 having the staple fiber material collected into distinct assemblages to thereby form a slubbed yarn.
4. Yarn according to claim 1 wherein said staple fiber material is collected into distinct assemblages spaced randomly along the length of said continuous filaments.
S. Yarn according to claim 1 wherein said staple fiber material and said continuous filaments are chemically dissimilar and the staple fiber material is collected into distinct assemblages.
6. Yarn according to claim 5 wherein said continuous filanlients are of nylon and said staple fiber material is woo 7. Yarn according to claim 5 wherein said continuous filaments are glycol-terephthalate polyester filaments and said staple fiber material is cotton.
8. Yarn, suitable for use in the formation of apparel fabrics, composed of at least about 5 generally parallel filaments twisted together with staple fiber material, said staple fiber material being continuously distributed along the length of said strand, the staple fibers having an average length of at least about 25 times the mean diameter of the yarn and being generally aligned with said filaments but being entwined among said filaments such that extensive movement of said staple fiber material along the longitudinal axis of said yarn is prevented as a result of such entwinement, and sufiziciently entangled to substantially contribute to the strength of said yarn.
9. Yarn according to claim 8 wherein said staple fiber material constitutes at least about 30%, by weight, of the yarn.
10. Yarn according to claim 9 wherein said filaments are twisted together with at least about turns per inch of twist.
11. Yarn according to claim 10 wherein the staple fibers are cotton and said filaments are formed from a polyester material.
12. Yarn according to claim 10 wherein the staple fibers are cotton and said filaments are nylon.
13. Yarn according to claim 10 wherein the staple fibers are wool and said filaments are formed of a fibers are wool and said filaments are formed from an acrylic material. v
15. Yarn according to claim 8 comprising at least about 10 filaments and wherein said staple fibers have an average length of at least about times the mean diameter of the yarn.
16. Yarn according to claim 15 wherein said filaments are twisted together with at least about 10 turns per inch of twist and the staple fiber material constitutes from about 40 to by weight, of the yarn.
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