US20060037154A1 - Multi-colored pile fabric and process - Google Patents

Abstract

A novel textile fabric comprised of pile-like yarns in which individual component yarns, at least one of which is texturized, comprising individual pile-like yarns have different shrinkage characteristics, and a method for making and patterning such fabrics. Upon the application of a shrinkage agent (e.g., heated air streams), either uniformly or selectively to the pile surface, the individual component yarns shrink to different degrees. By shrinking the relatively high shrinkage component yarns more than the adjacent relatively low shrinkage component yarns, the visual exposure of the relatively low shrinkage yarns is increased, and the visual contribution of the aesthetic qualities (e.g., color, light reflectivity, etc.) of such low shrinkage yarns is enhanced.

Description

• This disclosure relates generally to a method for selectively imparting multiple colors in a pattern configuration to a textile fabric having a multi-level pile or napped surface in which the surface pile or nap contains individual yarns comprised of two or more component yarns or fibers with different shrinkage and dyeing characteristics, and to the resulting multi-colored patterned fabric. In particular, this disclosure relates to a product and process in which the face of a pile or napped fabric is formed from yarns of at least two different types, having different shrinkage characteristics and different dyeing characteristics, and wherein one of the yarns is a textured yarn. The formed fabric is exposed to a shrinkage agent, such as heat, which can be applied uniformly or selectively (i.e., in a pattern). In either case, yarns of one type comprising the pile or nap are preferentially shrunk relative to yarns of the other type(s). Because of differences in dyeing characteristics, the yarns also dye differently when dye is applied to the fabric, which may also be done uniformly or selectively, and which may occur prior to or following the application of the shrinkage agent. By preferentially shrinking yarns of a given type, the height of such yarns is lowered, thereby allowing other yarns to become more exposed and therefore more visually prominent. In the finished product, such visually prominent yarns may have a different color, reflectivity, or other visually distinguishing characteristic as compared with the face yarns that are less exposed. It is contemplated that, where the shrinkage agent and the dye are both applied selectively in a pattern configuration, the different patterns may be in registry, if desired.
DESCRIPTION OF SELECTED EMBODIMENTS
• For convenience, the following is a brief summary of the Figures that will be referred to below.
• FIGS. 1A through 1E are process flow diagrams for several embodiments of the development described herein, in which (1) overall dyeing of yarns or fabrics, (2) pattern-wise shrinkage of fabrics, and (3) pattern-wise dyeing of fabrics may be optionally included and/or sequenced to produce pile fabrics in accordance with the teachings herein.
• FIGS. 2A and 2B show, diagrammatically, a cross section of a cut pile fabric comprised of collaged bi-component yarns in which both yarns are textured, as discussed in Examples 1-3 herein. InFIG. 2A, the fabric has not been treated by the selective application of heated air streams; inFIG. 2B, the fabric has been so treated.
• FIGS. 3A through 3D show, diagrammatically, a cross section of a cut pile fabric comprised of non-collaged bi-component yarns in which only one yarn is textured. As discussed in Example 3, one of the yarns (Yarn1) is flat polypropylene, while the other (Yarn2) is a textured polyester.FIG. 3A depicts the pile with no selective shrinkage; 3B depicts the pile following the selective application of heated air streams only on the face of the fabric;FIG. 3C depicts the pile following the selective application of heated air streams only on the back of the fabric;FIG. 3D depicts the pile following the selective application of heated air streams on both the face and the back of the fabric.
• FIGS. 3E and 3F show, diagrammatically, a cross section of a cut pile fabric comprised of tri-component yarns in which two of the yarns are tacked together and the third yarn is flat, as discussed in Example 8 herein. InFIG. 3E, the fabric has not been treated by the selective application of heated air streams; inFIG. 3F, the fabric has been so treated.
• FIGS. 4A and 4B show, diagrammatically, a cross section of a loop pile fabric comprised of collaged bi-component yarns in which one yarn is textured and one yarn is flat, as discussed in Example 9 herein. InFIG. 4A, the fabric has not been treated by the selective application of heated air streams; inFIG. 4B, the fabric has been so treated.
• FIG. 5 is a schematic side elevation view of apparatus for heated pressurized fluid stream treatment of a moving, needled, textile fabric to impart a surface pattern or change in the surface appearance thereof.
• FIG. 6 is an enlarged partial sectional elevation view of the fluid distributing manifold assembly of the apparatus ofFIG. 5.
• FIG. 7 is an enlarged broken away sectional view of the fluid stream distributing manifold housing of the manifold assembly as illustrated inFIG. 6.
• FIG. 8 is an enlarged broken away sectional view of an end portion of the fluid stream distributing manifold housing.
• FIG. 9 is a graph comparing percentage of shrinkage as a function of temperature for a number of fiber types.
• FIG. 10 is a schematic side elevation view of apparatus for laser beam treatment of a moving textile fabric to impart a surface pattern or change in the surface appearance thereof.
• As used herein, the following terms shall have the indicated meanings:
• “Yarn” shall mean a continuous strand of textile fibers, filaments, or material in a form suitable for knitting, weaving, or otherwise intertwining to form a textile fabric, and especially to form the face yarns of a pile or napped fabric.
• “Pile-like yarn” shall mean a single element comprising the face of a pile or napped fabric; a pile-like yarn may be comprised of two or more individual yarns in close physical association; a plurality of such elements collectively form the face of the fabrics contemplated herein (i.e., pile fabrics or napped fabrics). A pile-like yarn can be comprised of a number of fiber filaments commingled or twisted together or a number of filaments laid together, either with or without a degree of twist.
• “Pile fabric” shall mean a fabric having a face comprised of pile-like yarns; the term is intended to include pile fabrics and napped fabrics, unless express wording or context indicates otherwise.
• “Component yarn(s)” shall refer to the various individual yarns, each having a distinct shrinkage characteristic, that are physically combined (e.g., commingled, collaged, etc.) to form an individual pile-like yarn on the face of the patterned fabrics contemplated herein. As contemplated herein, such individual pile-like yarns will be comprised of at least one relatively low shrinkage yarn and at least one relatively high shrinkage yarn, at least one of which is textured.
• “Bi-component pile yarn” shall mean a pile-like yarn comprised of one relatively high shrinkage component yarn and one relatively low shrinkage component yarn. Typically, but not exclusively, the component yarns will be distinguishable in at least one other visually apparent characteristic (e.g., different color, reflectivity, cross-section, etc.).
• “Multi-component yarn” shall mean a pile yarn comprised of at least three component yarns, at least one of which is a relatively high shrink yarn and at least one of which is a relatively low shrink yarn. Other component yarns may have intermediate shrinkage characteristics, or may have similar high or low shrinkage characteristics, but be otherwise distinguishable. In either case, such component yarns typically will be distinguishable in at least one other visually apparent characteristic (e.g., different color, reflectivity, dyeability, etc.).
• “Aesthetic characteristics”, as that term is applied to yarns, shall refer to those characteristics relating to the appearance, shape (overall or cross-sectional), or configuration of such yarns, including, but not limited to, their reflectivity, color, or capacity for being dyed using appropriate dyes.
• “Shrinkage”, as that term is applied to fibers or yarns, shall refer to a lengthwise contraction or shortening of such fibers or yarns, as is associated with boiling water shrinkage or hot air shrinkage, for example. It is also specifically intended to include, without limitation, shortening due to the softening or melting of polymeric fibers or yarns.
• “Low shrink yarns” shall refer generally to component yarns that, relative to other component yarns forming the pile-like yarn, exhibit low shrinkage when exposed to a shrinking agent. When the shrinking agent is heat and the yarns are polymeric, low shrink yarns are typically those having a relatively high melting point. Yarns that have been dyed prior to such heat treatment tend to become low shrink yarns, even if, in undyed form, the yarns exhibited significant shrinkage.
• “High shrink yarns” shall refer generally to component yarns that, relative to other component yarns forming the pile-like yarn, exhibit high shrinkage when exposed to a shrinking agent. When the shrinking agent is heat and the yarns are polymeric, high shrink yarns are typically those having a relatively low melting point.
• “Lengthwise-coupled yarn” shall mean yarn comprised of at least two separate component yarns that are physically associated with each other to the extent that they can be treated as a single yarn in a fabric forming machine to form the face of the pile or napped fabric contemplated herein.
• “Collaged yarn” shall mean a lengthwise-coupled yarn in which the component yarns have been physically commingled or tangled along their length to form a bi-component or multi-component yarn.
• The method and product that is the subject of this disclosure begins with the formation of a bi- or multi-component yarn that will form the individual pile-like elements on the face of a pile or napped fabric. A characteristic of the development disclosed herein is the use of component yarns containing yarns having significantly different shrinkage characteristics when exposed to similar shrinkage agents. For example, the pile or napped fabric may contain individual pile-like yarns that are comprised of two component yarns (e.g., the pile-like yarn is a bi-component yarn), in which the first such component yarn is of a type that exhibits a first type of shrinkage (e.g., relatively low shrinkage or relatively high melting point characteristics), and the second such component yarn is of a type that exhibits a second type of shrinkage different from the shrinkage of the first component yarn (e.g., moderate or high shrinkage or low melting point characteristics, relative to the first component yarn type). Preferably, at least one of the yarns is textured.
• The objective when using a two component yarn is to construct a pile-like yarn which, under the influence of selectively applied streams of heated air or some other means to induce shrinkage of the component fibers (e.g., chemical means, steam, etc.), will cause yarns of the second type to shrink more than yarns of the first type, to a degree that imparts a perceptible visual effect to the face of a fabric containing such pile-like yarns. If the component yarns initially are about the same length, component yarns having the second characteristic will selectively shrink below the level of the component yarns of the first type, thereby exposing more of the latter yarns and causing those yarns to become more observable. If these component yarns of the first type are dyed a different color or are otherwise visually distinguishable (e.g., have increased or decreased reflectivity) from those component yarns of the second type, then the color or other visual effect (e.g., reflectivity) associated with these more observable component yarns of the first type likewise will become more observable. It should be noted that, while the component yarns used in the formation of the pile-like yarns may be either dyed or undyed prior to the fabric formation process, where the fabric is intended to have dyed pile-like yarns, generally at least one of the component yarns is dyed prior to the fabric formation process, and at least one is dyed following such fabric formation process.
• It is contemplated that this concept can be applied to pile-like yarns containing more than two component yarn types (i.e., multi-component yarns) in which at least one of the component yarn types has a shrinkage characteristic different from the other component yarn types. For example, if a pile-like yarn comprised of three component yarns, each having about the same length but each having a different shrinkage characteristic, is exposed to an appropriate shrinking agent (e.g., selectively applied heated air streams of the proper temperature), the various component yarns will each shrink to a different degree. If each of the three component yarns is associated (either prior to or following the fabric formation process) with a different color or other visually distinguishing characteristic, a number of different complex visual effects may be generated, depending upon the visual characteristics associated with each of the respective component yarns (e.g., light vs. dark, complementary vs. non-complementary colors, etc.), the angle of the incident light, the angle of the applied heated air streams, the length and pile or nap density (i.e., yarns per substrate unit area) of the pile-like yarns, the direction and uniformity of pile lay, the nature and degree of reflectance associated with the various component yarns (which, in turn, may depend upon the composition, cross-sectional shape, surface smoothness, and color of the component yarns), the manner and extent to which the component yarns are length-wise coupled, and other factors.
• It is also contemplated that, where three different types of component yarns are used, two of the component yarn types could have similar shrinkage characteristics, thereby providing for situations in which those yarns comprise a majority component. In such cases, if the minority component yarn type has relatively low shrinkage compared with the other component yarn types, it will provide a somewhat subtle visual contribution to the pile or napped face. Alternatively, if the minority component yarn type has relatively high shrinkage compared with other component yarn types, such shorter minority yarns will tend to recede into the pile or napped face and allow the visual contribution of the longer majority component yarns to dominate.
• In similar fashion, fabrics having a pile or nap comprised of four (or more) component yarns can be used, with the resulting visual effects having a potential for a correspondingly higher degree of subtlety and complexity. Accordingly, where the following discussions of techniques and process steps refer to pile-like yarns comprised of bi-component yarns, such discussions generally are also applicable to situations in which the pile-like yarns are comprised of multi-component yarns. As discussed above, in most embodiments, at least one of the component yarns is dyed prior to the fabric formation process.
• It is further contemplated that, in order to achieve certain visual effects, yarns of at least-one type may be different in length from other yarn types comprising the pile or nap even prior to the application of a shrinkage agent. For example, component yarns that are longer, but have a greater propensity to shrink, may be made to shrink below the level of shorter component yarns that have a lesser propensity to shrink. If the initially longer yarns have greater reflectivity, the areas in which shrinkage does not occur will exhibit higher luster, shine, or iridescence than the areas in which the higher reflectivity fibers are shorter or partially hidden by the lower reflectivity component yarns that were initially shorter. If, on the other hand, the higher-shrinkage component yarns were already shorter than other, relatively low shrinkage component yarns, the length differences between the two yarn types can be enhanced, causing the higher shrinkage yarns to recede further in the direction of the fabric base, with a corresponding increase in visual prominence of the lower shrinkage yarns and accentuation of the multi-level nature of the fabric.
• By careful selection of the length and shrinkage characteristics of the component yarns, it is possible to construct pile or napped fabrics in which the relative length of the component yarns may be controlled, both in areas that are subjected to the application of a shrinkage agent as taught herein, and in areas, if any, in which such shrinkage agent is not applied. In each case, the resulting visual effect generally follows the principle that component yarns that are longer, more reflective, or more densely positioned or represented will dominate the overall appearance of the pile or napped fabric relative to similarly colored, but shorter, less reflective, or more sparsely positioned or represented component fibers.
• One example of a process as described herein is diagrammed inFIG. 1A. As shown at10A and10B,Yarn1 andYarn2 are component yarns that are used to construct a yarn used to form the face of a pile or napped fabric. For discussion purposes, it shall be assumed thatYarn1 exhibits relatively low shrinkage (i.e., little reduction in yarn length), as compared withYarn2, when exposed to a shrinkage agent. When the shrinkage agent is heat,Yarn1 preferably has a relatively high melting point or a lower shrinkage capacity (perhaps due to yarn pre-treatment such as package dyeing), as compared withYarn2, andYarn2 preferably has a relatively low melting point or a higher shrinkage capacity, as compared withYarn1. Accordingly, when exposed to the same shrinkage agent (e.g., heat) under similar conditions,Yarn2 will shrink more thanYarn1 to a visually significant degree. Examples of possible fiber types that could be employed in the construction ofYarn1 include low shrinkage heat set polyester, low shrinkage heat set nylon, or a low shrinkage cellulosic fiber such as rayon, acetate, or cotton. Examples of possible fiber types that could be employed in the construction ofYarn2 include low melting point polypropylene or high shrink polyester. Preferably, eitherYarn1 orYarn2 is textured.
• Yarns1 and2 may be dyed by any means suitable for the nature of the constituent fibers. For example, yarns comprised of polypropylene, polyester, or nylon fibers may be solution dyed or package dyed, but the use of disperse, cationic, acid, direct, reactive, or VAT dyes is also contemplated, as will be apparent to those skilled in the art, depending upon the composition of the fibers to be used. If polypropylene is used and is intended to carry a color, it is recommended that it be solution dyed for best results.
• Yarn1 andYarn2 may be individually or collectively dyed or undyed, but if one or both are undyed, then preferably at least one of the undyed yarn(s) is capable of being dyed using conventional dyeing techniques following the fabric formation step. It should be noted that, in the case of package dyed yarns, such yarns characteristically have little propensity to shrink. Accordingly, it has been found that package dyed yarns are better candidates to serve as Yarn1 (relatively low shrinkage) rather than asYarn2.
• Yarn3, indicated as optional at10C, depicts a situation in which a multi-component yarn comprised ofYarn1,Yarn2, andYarn3 is used to form the pile-like face.Yarn3 may be dyed or undyed. The shrinkage characteristics ofYarn3 most commonly will be different from eitherYarn1 orYarn2, i.e., it may be intermediate between the shrinkage characteristics ofYarns1 and2, or it may be even higher than that ofYarn2. It should be noted that it is also contemplated thatYarn3 may have a shrinkage characteristic that is substantially similar to eitherYarn1 orYarn2, or perhaps even less than that ofYarn1, depending upon the nature of the visual effect to be achieved when a shrinkage agent is applied to the multi-component pile-like yarn. As suggested above, it is contemplated that additional yarns (e.g., a fourth yarn, a fifth yarn, etc.) of various types and having various shrinkage characteristics may be used to form multi-component yarns from which the pile or napped fabric is constructed. In such cases, the shrinkage characteristics of such additional yarns may be either similar or different from other yarns; the processing steps described herein apply regardless of the number of different component yarns used, except that separate dyeing steps may be necessary (depending upon the desired visual effect) following fabric formation if such yarns are undyed prior to the fabric formation process.
• Step20 ofFIG. 1A represents the selected process by which the bi- or multi-component yarns that ultimately will form pile-like yarns are generated. This process generally involves the length-wise coupling of two or more component fibers or yarns so that the component fibers or yarns can be treated as a single yarn during the fabric formation process. This coupling may involve the formation of collaged yarns, parallel yarns, twisted or multi-ply textured yarns, or other types of yarns in which two or more individual component yarns are physically associated in a way that forms a bi- or multi-component yarn capable of serving as the pile-like yarns of a pile or napped fabric. Examples of candidate processes include methods that result in the generation of a collaged yarn, such as air jet commingling, twisting, use of a stuffer box, etc. or methods used to form textured yarns such as crimping, false twist texturing, air jet texturing (a wet process), etc. It should be understood that the various component yarns can represent a mixture of different deniers, cross-sections, diameters, or the like.
• Following this step, the length-wise coupled bi- or multi-component yarn is used in a conventional pile or napped fabric formation process, indicated atStep50 ofFIG. 1A. Because the effects described herein generally depend much more upon the nature of the yarns comprising the pile or napped face of the fabric than upon the nature or construction of the back or ground of the pile or napped fabric, any of several known processes for forming a pile or napped fabric may be used, so long as the resulting pile or napped surface is formed from the bi- or multi-component yarns of the kinds described above. Examples of such processes include circular knitting, double needle bar knitting, warp knitting, woven velour weaving, tufting, or the conventional formation of a flat fabric that is subjected to a napping step, all as may be available to one skilled in the art.
• In one embodiment, the pile fabric may be formed in a double needle bar knitting machine, which forms a fabric “sandwich”, in which the pile face is turned inward and spans opposing backing substrates. It should be noted that if the pile fabric is to be formed on a double needle bar knitting machine, thenYarn1 andYarn2 can be combined by warpingYarn1 andYarn2 individually, on separate beams, and threading an individual warp yarn from each beam through the same needle of the double needle bar knitting machine. This effectively combines the yarns at the same time the pile fabric is being formed and results in a bi-component pile without the need for a separate step to generate the bi-component yarn. Conversely, if the pile or napped fabric is woven, then physical commingling ofYarns1 and2 can be achieved by feeding respective warp ends ofYarns1 and2 through a common heddle, without the need for a separate step to generate the bi-component yarn. Where appropriate, similar approaches can be used involving multi-component yarns.
• Individually optional processes that may be associated with the formation of the fabric having a pile-like face are indicated atSteps30 and40—one or the other steps may be used, as necessary, depending upon the processes used in thefabric formation Step50. If the fabric formation process involves the formation of a “sandwich” fabric,Step30 indicates a conventional process commonly associated with the manufacture of, for example, double needle bar fabrics, in which the “sandwich” is slit or split in half, parallel to the plane of the fabric. This process step forms two pile fabrics, each having a pile height corresponding to half the distance that separated the opposing backing substrates.
• In the event the pile fabric formation process does not involve the formation of a “sandwich” fabric but instead involves the initial formation of a fabric with a loop pile face,optional Step40 represents a process in which the loops are cut, thereby resulting in a fabric having a cut loop pile face, in which individual component yarns presumably are less constrained with respect to shrinkage. This can be achieved by napping, shearing, or any other process that effectively cuts the loops. If a loop pile fabric is to be used without such loop-cutting step, as shown inFIGS. 4A and 4B and discussed in connection with Example 9, then neither ofSteps30 or40 is necessary. The loops, following the application of a shrinkage agent, tend to provide a coarsened or heathered appearance that may lack the definition possible with a cut pile face, but that may be aesthetically desirable for certain applications. However, it is anticipated that, in most cases, a cut pile fabric will be used due to the higher patterning definition possible.
• As indicated atStep60 ofFIG. 1A, once a fabric having the desired pile-like face has been formed, the fabric optionally may be brushed and preferably lightly heat set at a relatively low temperature (one that will not affect shrinkage to any significant degree) and dimensioned to a standard width. The fully formed, lightly heat-set fabric that emerges fromStep60 is then ready to be visually enhanced by the application of shrinkage agents causing visible shrinkage of Yarn2 (the relatively high shrinkage component yarn) relative to Yarn1 (the relatively low shrinkage component yarn) in accordance with pattern data, indicated atStep70. As a result of this relative shrinkage,Yarn1 is preferentially exposed in selected areas across the face of the fabric and, accordingly, the color or other visual characteristic associated withYarn1 is allowed to become more visually prominent in those selected areas of the fabric face. If a multi-component fabric is used, thisStep70 could also be used, as desired, to cause pattern-wise shrinkage of other yarns (e.g.,Yarn3, Yarn4, etc.) relative toYarn1. Although results will depend upon a number of factors known to those skilled in the art, it is anticipated that the linear shrinkage ofYarn1 will be less than about 10%, and preferably less than about 6%, and more preferably less than about 3%, while the linear shrinkage ofYarn2 will be greater than about 12%, and preferably greater than about 15%, and more preferably greater than about 20%.
• In one preferred embodiment, the shrinkage agent is heated air that is applied to the surface of the fabric. Although the remaining description herein is directed to the selective application of such heated air, it is contemplated that other shrinkage agents, such as application of a laser (see below), steam, or a liquid shrinkage agent, can be used if desired, so long as the effect is to induce relative shrinkage to one set of yarns (e.g., Yarn2) without inducing the same linear shrinkage to a second set of yarns (e.g., Yarn1). As discussed elsewhere, the application of the shrinkage agent of choice may be done uniformly if a uniform effect is desired, but, perhaps preferably in most applications, may be done selectively, in accordance with pattern information, either to establish a pattern on the fabric or to enhance an existing pattern (e.g., a dyed pattern) by inducing shrinkage of component yarns in registry with selected elements of such existing pattern.
• Where heated air streams are used, the temperature of the individually controllable streams of air, as they contact the surface of the fabric, is sufficient to cause localized shrinkage or melting of the high shrinkage or low melting point component yarns comprising the pile-like surface, and to cause significantly less shrinkage to other component yarns comprising the pile-like surface. This not only reduces the visual contribution of the shrunken component yarns in those treated areas, but, because the length of the component yarns have been reduced in such areas, the backing substrate may be less hidden by the pile-like surface, and may contribute to the overall visual effect of the fabric in those areas, depending upon the overall construction of the fabric. By adjusting the temperature of the heated air streams, it is possible to adjust correspondingly the degree to which the component yarns are subjected to shrinkage or melting—in general, higher temperatures, within a reasonable range, providing increased shrinkage or melting. Generally, melting points for the low shrinkage/high melting point component yarns will lie within the range of about 460° F. to about 750° F, and preferably between about 480° F. and about 500° F, while melting points for the high shrinkage/low melting point component yarns will lie within the range of about 280° F. to about 340° F, and preferably between about 300° F. and about 320° F.
• In one embodiment, the pile-like face of the fabric, prior to the application of the heated air streams, will have uniform pile lay and a relatively uniform color and appearance—the product of the combination of the colors ofYarn1 andYarn2 as they are distributed over the fabric surface during the fabric formation process. The heated air streams are applied selectively, in a pattern configuration, over the surface of the fabric. The effect is to induce selective shrinkage in the pattern areas of one type of component yarn (e.g., the “high shrinkage” Yarn2), thereby making the visual contribution of another type of component yarn that is not shrunken to the same degree (e.g., Yarn1) more visually prominent. BecauseYarn1 will now have more visual exposure, its visual characteristics such as color or reflectivity will tend to influence the overall appearance of the pile-like surface in those pattern areas. It is also contemplated that the heated air streams (or other shrinkage agent of choice) may be applied uniformly to the otherwise unpatterned pile-like surface, thereby generating a color formed primarily by the visual differences between component yarns that have been selectively shrunken and those that have not.
• Step70 ofFIG. 1A can optionally be followed by adyeing Step80, in which the undyed component yarns, if any, forming the pile-like yarns are dyed. Where the undyed component yarn is polyester, this step may be performed using conventional jet dyeing techniques associated with a disperse dye cycle, in which the fabric is formed in a loop and circulated within a conventional jet dyeing apparatus. If the undyed component yarn is other than polyester, dyeing processes appropriate to that yarn type may be used. In the case of a fabric comprised of multi-component yarns with both components requiring piece dyeing,Step80 may consist of several sequential dyeing steps, perhaps one for each different type of component yarn, in order to achieve the desired effect. If no undyed component yarns are used to form the pile-like surface,Step80 could be bypassed.
• Alternatively, it is contemplated that the pile-like surface can be selectively dyed in a pattern configuration following—or prior to—the selective application of the heated air streams. In the latter case, it is recommended that such selective dyeing be carried out without causing appreciable shrinkage of the selectively dyed yarns (or at least shrinkage that is visually similar to that brought about by the selective application of the selected shrinkage agent, e.g., heated air streams). This will then provide the opportunity to apply the heated air streams (or other shrinkage agent of choice) to the fabric in registration with certain elements of the dyed pattern, thereby creating a pattern in which the appearance of any given area within the pattern will depend not only upon the color of the surface as pattern dyed, but also upon the degree to which the various component yarns comprising the pile-like surface in that area have been selectively shrunken. Such selective dyeing may be achieved by any appropriate conventional means, such as screen printing or through the use of a metered jet patterning device such as described in commonly-assigned U.S. Pat. Nos. 4,984,169, 5,128,876, 5,136,520, 5,140,686, 5,142,481, 5,195,043, and 5,208,592, the teachings of which are hereby. incorporated by reference.
• As suggested by the discussion above and depicted inFIGS. 1B through 1E, the nature and sequence of processsteps following Step60 are not restricted to those shown inFIG. 1A. Other sequences of dyeing and/or patterning that are capable of producing visually interesting fabrics are set forth, along with those discussed above, in the following Table 1 (in whichFIG. 1A represents an example of Sequence No. 1). It should be noted that, inFIGS. 1A through 1E, necessary conventional dye fixing and/or drying steps appropriate to the selected dyeing process are assumed, and are not shown.

  TABLE 1
  Sequence No.	1	2	3	4	5	6	7	8
  Corresponding	1A	1B	None	1C	1D	1E	None	None
  FIGURE No.
  Dye	NO	YES	YES	YES	NO	Pattern	Pattern	Pattern
  						Dye	Dye	Dye
  Selectively Shrink	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
  Dye	YES	NO	YES	Pattern	Pattern	NO	YES	Pattern
  				Dye	Dye			Dye

• InFIG. 1B (an example of Sequence No. 2), a process is shown in which the fabric emerging fromStep60 is dyed (e.g., in a dye jet) prior to being subjected to the pattern-wise shrinkage ofStep70.
• InFIG. 1C (an example of Sequence No. 4), the depicted process is one in which the process ofFIG. 1B is extended, following the pattern-wise shrinkage step indicated at70, to includeStep75, in which dye is selectively applied to the fabric. This dye-generated pattern optionally can be in registry with the pattern already imparted to the fabric viaStep70, or can be in a pattern that is complementary to, or completely independent of, the pattern defined by the pile height differences brought about byStep70.
• InFIG. 1D (an example of Sequence No. 5), the depicted process is that ofFIG. 1C with the omission of the initial dyeing step (Step65 inFIG. 1C). As discussed in connection withFIG. 1C, the dye-generated pattern may be imparted inStep75 in registry with the pattern imparted byStep70, but need not be, depending upon the aesthetic effect desired.
• InFIG. 1E (an example of Sequence No. 6), the step imparting a pattern defined by pile height differences (achieved using, e.g., the selective application of heated air) and the step imparting a pattern defined by the selective application of dye (Steps70 and75, respectively, inFIG. 1D) are done in reverse order. The pattern defined by pile height differences may be in registry with the dye-generated pattern, or, optionally, may be in a pattern that is complementary to or independent of the dye-generated pattern.
• The nature of the visual effects obtained using the processes described above is dependent upon a variety of factors, including, importantly, the color of the component yarns, the configuration of the yarns in the tuft, the method of applying the shrinkage agent (e.g., if heated air, whether such air is applied to the face or back of the fabric, or both), and the relative length of the component yarns both before and after the application of a shrinkage agent. It has been found that if one or more of the component yarn types exhibit a significantly higher degree of light reflectivity than other component yarns (as, for example, flat or non-textured yarns), and those yarns are not obscured by other, less light reflective yarns, then these higher reflectivity yarns can provide a distinct and aesthetically pleasing iridescence that changes with pile lay and angle of observation.
• Component yarns of the following exemplary types have been found to be suited to the development of pile or napped fabrics having an iridescent effect, although other component yarn types will be apparent to those skilled in the art. In each case,Yarn1 represents a textured, relatively low shrinkage component yarn andYarn2 represents a component yarn capable of relatively moderate or high shrinkage and low or no crimp. Furthermore, it is preferred that eitherYarn1 orYarn2 be capable of being dyed following the fabric formation step, while the other ofYarn1 orYarn2 is incapable of accepting the dyes to be used to dye the formed fabric. Excellent results have been achieved by using, as aYarn1, a piece-dyeable yarn. Examples of suitable candidate yarns are as follows:
• Type 1 Yarns (relatively low shrinkage): (a) heat set nylon (preferably, textured) or heat set polyester (flat or textured), or (b) flat or spun cellulosic fiber (e.g., cupramonium rayon, rayon, acetate, cotton).
• Type 2 Yarns (relatively moderate or high shrinkage): (a) flat polypropylene, (b) high-shrink nylon (preferably, flat) or polyester (preferably, flat).
• If pile or napped fabrics having a pile-like face constructed of multi-component yarns are desired, combinations of three or more yarns from the above list can be used, as well as others that will be readily apparent to those skilled in the art. The effects obtained will depend upon the same general factors involved in the bi-component case, and are likely to depend heavily upon the relative ratio, distribution, and length of the various component yarns used.FIG. 9 shows estimates of shrinkage levels, as a function of temperature, for eight candidate yarn materials. Other yarn materials may also be used.
• The following are selected representative examples of the processes disclosed herein. Unless otherwise specified, the individual process steps are described briefly in the following table. As will be evident, some Steps, even if not noted as “Optional,” may not be used in each Example. Note that fabric dyeing can occur either prior to or following the application of the shrinkage agent, or both.

  TABLE 2
  STEP	COMMENT
  Dye or otherwise process	Optional, depending upon effect desired.
  one or more of the selected
  individual yarns
  Commingle yarns	In most cases, each fiber tuft in the fabric to
  	be formed will contain each of the constitu-
  	ent yarns.
  Warp yarns	As required for the selected fabric formation
  	process (e.g., weaving, knitting).
  Form fabric (e.g., weave or	In most cases, thread-up will result in each
  knit)	dent or needle containing an end of each
  	yarn.
  Cut loops formed in Step D	This step includes slitting, shearing, napping,
  	etc.
  Brush and/or heat set pile	This is useful in orienting and stabilizing pile
  	direction.
  Dye fabric	Optional; can be piece dyed or pattern dyed;
  	drying optional if heated air streams used.
  Apply shrinkage agent	In Examples, heated air streams are used, as
  (perhaps selectively)	described herein, with pile oriented in for-
  	ward direction (i.e., in direction of substrate
  	movement, not in “slick” direction).
  Dye (and dry) fabric	Optional; can be piece dyed or pattern dyed

• The abbreviations “CPI” and “WPI” mean, respectively, courses per inch and wales per inch. Unless otherwise specified, all length dimensions are in inches, and all temperature readings are in ° F. and are approximate.
EXAMPLE 1
• Yarn1: 150/36 flame red solution dyed flat polypropylene (round cross-section; nominal self-entanglement)
• Yarn2: 1/150/50 dark pewter package dyed textured polyester (octolobal cross-section; high self-entanglement).
• Note: These yarns were combined, in accordance with the process described below, to form a pile fabric having pile tufts comprised of 2-ply Solution Dyed Polypropylene and 1-ply Textured Package Dyed Polyester.
• Yarn
• Entanglement: Collage, via processing on an RPR Collaging Machine
• • 1st Delivery (A): disabled to process the flat polypropylene
  • 2nd Delivery (C:D): draw ratio (D:C) set to 1.03
  • Speed: 400 m/min
  • Working Jet Pressure: 75 psi
• Warp: 1070 ends of collaged polypropylene/textured polyester on 1 Beam (Bar 3)
• Fabric Formation: Knit: 32 GG Double Needle Bar Knit Machine
• • Gap: 5.00 mm
  • Courses per Inch (CPI): 28.00
  • Sandwich Thickness: 0.220″
  • Threaded FULL
• Slit: CPI (in): 29.0, CPI (out): 28.0, WPI (in): 33.0, WPI (out): 33.0, Width (in): 65.5″, Width (out): 65.00″
• • Pile Height: 0.115″ (TOPS)+0.115″ (BOTTOMS)
• Brush/Heatset: CPI (in): 28.0, WPI (in): 33.0, Width (in): 65
• • Brush Settings: #1: 7.1 (UP), #2: 1.2 (DOWN), #3: 7.1 (UP), #4: 3.1 (UP)
  • Temperature: 340° F.
  • Speed: 15 ypm
  • Entry Rail Setting: 64″, Exit Rail Setting: 66″
• The resulting fabric at this stage of processing is depicted inFIG. 2A.
• Selective Application of Shrinkage Agent: Heated air streams (i.e., Millitex®) on fabric face.
• • Temperature: 370° F.
  • Speed: 3.5 ypm
  • Hot Air: 2.0 psi/Blocking Air: 15 psi
• RESULTS: Depicted inFIG. 2B. The fabric yielded a two-color design, due to polypropylene and polyester having different colors. Due to commingling of these two fiber types, the color was determined by the extent of the shrinkage of the lower melting point fiber (e.g., the polypropylene), which, in turn, was controlled by the temperature of the heated air streams applied to the component yarns comprising the pile face of the fabric. Where little shrinkage of both fiber types occurred, the color was a blend of the colors of the respective fibers. Where the heated air streams caused significant shrinkage (due to melting) of the polypropylene yarns, with the polyester yarns being substantially unaffected, the color was predominantly that of the relatively exposed polyester yarns. The commingling of the two different yarn types prevented the non-textured polypropylene from standing above the height of the textured polyester in the fabric tuft, thereby producing a non-iridescent effect. The fabric appeared streaky, probably due to the insufficient commingling that resulted from use of highly entangled package dyed polyester and polypropylene.
EXAMPLE 2
• The same starting yarns were used as in Example 1, but they were processed to form a pile fabric having pile tufts comprised of 2-ply Textured Package Dyed Polyester and 1-ply Solution Dyed Polypropylene, i.e., textured polyester yarns were package dyed and collaged with flat polypropylene yarns and yielded a streak-free fabric base. All processing steps were similar to those listed in Example 1, except the Millitex® treatment values. Because the relative proportion of lower melting point polypropylene to higher melting point polyester in the pile face is a factor in determining how much heat is required to create the patterns, the Millitex® treatment values were as follows:
• • Temperature: 420° F.
  • Speed: 3.0 ypm
  • Hot Air: 2.5 psi/Blocking Air: 15 psi
• Results were essentially as recited in Example 1, except there were no objectionable streaks.
EXAMPLE 3
• The same starting yarns were used as in Example 1, but they were processed to form a pile fabric having pile tufts comprised of 2-ply Textured Package Dyed Polyester and 1-ply Cleartint® Solution Dyed Polypropylene (Cleartint® is a colorless polymeric colorant marketed by Milliken & Company, Spartanburg, S.C.). All processing steps were similar to those listed in Example 1, except the Millitex® treatment used the following process values:
• • Temperature: 460° F.
  • Speed: 3.0 ypm
  • Hot Air: 2.5 psi/Blocking Air: 15 psi
• Results were essentially as in Example 2.
EXAMPLE 4
• Yarn1: 150/72 Crimson Solution Dyed Polypropylene (delta cross-section); nominal entanglement
• Yarn2: (255)-100 56T POY Polyester (round cross-section), nominal entanglement, which was processed on an AFK-Barmag False Twist Texturing Machine by drawing at a 1.70 draw ratio across a contact heater maintained at 330° F. to yield a 1/150/100 56T Polyester, which was combined in a commingling jet at the end of the process with the 150/72 Crimson Polypropylene (Polypropylene bypassed texturing).
• Yarn3: (175)-150/48 full dull round warp drawn Polyester (warp made with a 1.25 cold draw ratio, followed by a 0.91 hot overfeed at 392° F. on a draw warper).
• Warp: Yarns1+2 (textured polypropylene/polyester) on 1 beam (Bar3);Yarn3 on 1 beam (Bar4) at 1120 ends/beam
• Fabric Formation: Knit on 32 GG Double Needle Bar Knit Machine
• Runner Lengths:Bar1/6: 125.40″,Bar2/5: 85.5″,Bar3/4: 320.00″
• • Gap: 5.00 mm
  • Courses per Inch (CPI): 28.00
  • Sandwich Thickness: 0.220″
  • Threaded FULL
• Slit: CPI (in): 28.0, CPI (out): 27.0, WPI (in): 33.0, WPI (out): 33.0, Width (in): 68.0″, Width (out): 67.5″
• • Pile Height—0.090″ (TOPS)+0.090″ (BOTTOMS)
• Brush Heatset: CPI (in): 27.0, CPI (out): 26.0, WPI (in): 33.0, WPI (out): 34.0, Width (in): 67.5″, Width (out): 65.5″
• Brush Settings: No.1: 7.1 (UP), No.2: 1.2 (DOWN), No. 3: 7.1 (UP)
• • Temperature: 250° F.
  • Speed: 15 ypm
  • Entry Rail Setting: 64″, Exit Rail Setting: 66″
• The resulting fabric at this stage of processing is depicted inFIG. 3E.
• Selective Application of Shrinkage Agent: Heated air streams (i.e., Millitex®) on the fabric face
• • Temperature: 370° F.
  • Speed: 2.5 ypm
  • Hot Air: 2.5 psi/Blocking Air: 15 psi
• Dye: Dyed a light Beige color (using 1/2 the weight of the fabric to calculate the dye concentrations since the polypropylene will not accept disperse dyes)
• • Top Temperature: 266° F. for 30 minutes
  • Disperse Dye Cycle
  • Rate of temperature Rise: 2° F./min
• Dry: Tumble Dried
• RESULTS: As shown inFIG. 3F. The fabric yielded a two-color design where the polypropylene/polyester textured yarn showed a blended “Crimson/Beige” color in the non-Millitex areas and beige from the polyester in the Millitex areas because the polypropylene was melted away due to its lower melting temperature. This fabric did not yield an iridescent effect; the texturing of the two yarns together kept the polypropylene from standing higher in the pile to allow reflection of the light, as in the non-commingled fabric. Random streaks of crimson were observed, due to the underdrawnyarn comprising Yarn3.
EXAMPLE 5
• Yarn1: a 150/72 Solution Dye (Crimson Red) Polypropylene (Doubled/non-commingled) yarn, (Delta Cross-section) high degree of texturing/self-entanglement
• Yarn2: a 1/150/50 242T Package Dyed (Dark Pewter) textured Polyester yarn (octolobal cross-section) high degree of texturing/post-entanglement (Milliken & Co. Fabric Style: CDY603)
• Yarn entanglement
• (Yarn1/Yarn2): None
• Warp: 1540 ends of Polypropylene on 1 Beam (Bar3)+1540 ends of Polyester on 1 Beam (Bar4)
• Fabric Formation: Knit—44 GG Double Needle Bar Knit Machine
• • Runner Lengths:Bar1/6: 91.60 in.,Bar2/5: 74.10 in.,Bar3/4: 313.90 in.
  • Gap: 5.0 mm
  • Courses per inch (“CPI”): 37.50
  • Sandwich Thickness: 0.198 in.
  • Threaded FULL
• Slit: CPI (in): 36.0, CPI (out): 33.0, WPI (in): 22.5, WPI (out): 23.0 in.,
• • Width (in): 68.5 in., Width (out): 67.5 in.
  • Sandwich Thickness (in): 0.201″
  • Resulting Pile Height: 0.1 05 in. (TOPS)+0.105 in. (BOTTOMS)
• Brush/Heatset: CPI (in): 33.0, CPI (out): 33.0, WPI (in): 23.0, WPI (out): 22.5, Width (in): 67.5″, Width (out): 65.8″
• • Brush Settings: #1: 7.1(UP), #2:1.2 (DOWN), #3: 7.1 (UP), #4: 3.1 (UP)
  • Temperature: 250° F.
  • Speed: 15 ypm
  • Entry Rail Setting: 64″, Exit Rail Setting: 66″
• The resulting fabric of this stage of processing is depicted inFIG. 3A.
• Selective Application of Shrinkage Agent: Heated air streams (i.e., Millitex®) on the fabric face
• • Temperature: 350° F.
  • Speed: 2.0 ypm
  • Hot Air: 2.0 psi/Blocking Air: 13 psi
• RESULTS: As shown inFIG. 3B. The fabric yielded a two-color design where the polypropylene—being a non-textured yarn—stood higher in the pile than the textured polyester package dye. When subjected to selective shrinkage, the polypropylene yarns melted down below the polyester yarns (due to the melting point difference between polypropylene and polyester). The areas in which the polypropylene yarns were substantially shrunken exhibited the color of the dark pewter package dyed polyester. The package dyed polyester yarns were substantially unaffected by the selective shrinkage step, due to a lack of significant shrinkage remaining in the fiber following the package dyeing step. In areas where the polypropylene yarns were not substantially shrunken, the blend of crimson polypropylene and dark pewter package dyed polyester resulted in a rose color. The appearance of the fabric was streaky due to the “plating” condition that can occur when a flat yarn and textured yarn are doubled in the same needle. The streaks were analyzed to be physical in nature, resulting from an excessive variation in shrinkage of the flat polypropylene yarns.
EXAMPLE 6
• Yarn1: 150/36 Forest Green Solution Dyed Polypropylene (delta cross-section) (Doubled/non-commingled); (high entanglement)
• Yarn2: 1/150/36 Heatset Textured Polyester (round cross-section; high degree of self-entanglement; low shrinkage: 3% boiling water shrinkage)
• Yarn Entanglement: None
• Warp: 1540 ends of Polypropylene on 1 Beam (Bar3); 1540 ends of Polyester on 1 Beam (Bar4)
• Fabric Formation: Knit: 44 GG Double Needle Bar Knit Machine
• Runner Lengths:Bar1/6: 91.10″,Bar2/5: 74.10″,Bar3/4: 313.00″
• • Gap: 5.00
  • Courses per Inch (CPI): 37.00
  • Sandwich Thickness: 0.196″
  • Threaded FULL
• Slit: CPI (in): 37.5, CPI (out): 34.0, WPI (in): 22.5, WPI (out): 22.5, Width (in): 68.5″, Width (out): 67.00″
• • Sandwich Thickness: 0.199″
  • Pile Height: 0.105″ (TOPS)+0.105″ (BOTTOMS)
• Sandwich Heatset: CPI (in): 36.0, CPI (out): 37.0, WPI (in): 22.5, WPI (out): 25.0, Width (in): 68.00″, Width (out): 65.00″
• • Sandwich Thickness (in): 0.198″, Sandwich Thickness (out): 0.177″
  • Speed: 15 ypm
  • Overfeed: 110%
  • Temperatures: 250° F.
• Slit: CPI (in): 37.5, CPI (out): 34.0, WPI (in): 22.5, WPI (out): 22.5, Width (in): 68.5″, Width (out): 67.00″
• • Sandwich Thickness: 0.199″
  • Pile Height: 0.105″ (TOPS)+0.105″ (BOTTOMS)
• The resulting fabric at this stage of processing is depicted inFIG. 3A.
• Selective Application of Shrinkage Agent: Heated air streams (i.e., Millitex®) on the fabric face
• • Temperature: 420° F.
  • Speed: 3.5 ypm
  • Hot Air: 2.5 psi/Blocking Air: 15 psi
• Dye: Dyed a Dark Shade (Royal Blue) and a Light Shade (Tan) (using 1/2 the weight of fabric to calculate dye concentration because disperse dye will not dye polypropylene.
• • Top Temperature: 266° F. for 30 min
  • Disperse Dye Cycle
  • Rate of Temperature Rise: 2° F./min.
• RESULTS: As shown inFIG. 3B. The fabric yielded a tonal fabric when dyed a darker shade (Royal Blue) and a two-color fabric when dyed a lighter shade (Tan). The Polypropylene color displayed an iridescent Forest Green quality in the non-Millitex® area because it stands taller than the textured crimped polyester. To maximize light reflective capability, the polypropylene is preferably a flat (non-textured) yarn with a “delta” cross-section.
EXAMPLE 7
• The same starting yarns and fabric preparation were used as in Example 6, except that the heated air streams were directed from the back of the fabric, rather than from the front.
• Selective Application of Shrinkage Agent: Heated air streams (i.e., Millitex®) from the back of the fabric
• • Temperature: 570° F.
  • Speed: 3.0 ypm
  • Hot Air: 3.5 psi/Blocking Air: 18 psi
• RESULTS: As shown inFIG. 3C. The fabric lost some of its iridescent appearance due to the higher heat required to shrink the polypropylene yarns from the back; polypropylene yarns in the non-Milltex® areas absorbed sufficient heat to shrink moderately and cause the length of the polypropylene yarns to be roughly equal to the length of the textured polyester yarns, thereby causing substantially uniform pile height in such areas. Because the heat was not directly applied to the face (pile) of the fabric, fabric hand was good.
EXAMPLE 8
• The same starting yarns and fabric preparation were used as in Example 4, except that the heated air streams were directed to both the face and the back of the fabric.
• Selective Application of Shrinkage Agent: Heated air streams (i.e., Millitex®), applied to front and back of the fabric
• • Temperature: 570° F. (Back−1st); 380° F. (Face−2nd)
  • Speed: 3.0 ypm+3.0 ypm
  • Hot Air/Blocking Air: 3.5 psi/18 psi+2.5 psi/15 psi
• RESULTS: As shown inFIG. 3D. Pattern definition in shrunken areas was high, with crisp boundary areas, due to nearly complete melting of the polypropylene yarns. As above, the higher temperature treatment on the back of the fabric shrunk the polypropylene yarns sufficiently that they were even in pile height to the textured polyester yarns.
EXAMPLE 9
• Yarn1: 150/72 Cleartint® Orange Solution Dyed Polypropylene (delta cross-section); high entanglement
• Yarn2: 1/150/50 Dk. Pewter Package Dyed Polyester (octolobal cross-section); high entanglement
• Yarn Entanglement: Collaged/Commingled on RPR Collaging Machine
• • 1st Delivery (A): disabled to process the flat Polypropylene
  • 2nd Delivery (C-D): ratio set to 1.03
  • Speed: 400 m/min
  • Working Jet Pressure: 75 psi
• Fabric Formation: Knit using 20 GG Monarch Circular Knitting Machine, forming a Low Loop to be processed uncut, followed by slitting to open the tubular circular knit to form a flat pile fabric. The resulting fabric at this stage of processing is depicted inFIG. 4A.
• Tenter: Temperature: 300° F.
• • Speed: 15 ypm
  • Exit Rail Width: 62″
• RESULTS: As shown inFIG. 4B. This sample was produced to examine the impact of creating a “Low Loop Pile” fabric with collaged Polyester/Polypropylene. The resulting fabric yields a “Heathered” pattern definition. Microscopically, the Millitex® hot air treatment is fused some of the loops but not necessarily all of them. Where they are not fused, the entire loop is shrunk down into the fabric base. The base fabric prior to the Militex® treatment was streaky as a result of trying to commingle two “high entanglement” fibers, a condition that can be resolved using low interlace yarns in the commingling step. After the Millitex® treatment, no streakiness was apparent.
EXAMPLE 10
• Yarn1: 150/40 Bright Acetate (Round cross-section; doubled but not commingled)
• Yarn2: 1/250/72 BCF Orange Cleartint Solution Dyed Polypropylene (delta cross-section); nominal entanglement
• Warp: 1120 ends warped on each beam
• Knit: 32 GG Double Needle Bar Knit Machine
• Runner Lengths:Bar1/6: 125.40″,Bar2/5: 85.50″, Bar3: 300.00″, Bar4: 300.00″
• • Gap: 5.0 mm
  • Courses per Inch (CPI): 29.00
  • Sandwich Thickness: 0.167″
  • Threaded FULL
• Slit: CPI (in): 29.0, CPI (out): 29.0, WPI (in): 33.0, WPI (out): 33.0, Width (in): 68.00″, Width (out): 67.50″
• Greige Brush Heatset: CPI (in): 29.0, CPI (out): 30.0, WPI (in): 33.0, WPI (out): 34.0, Width (in): 67.50″, Width (out): 64″
• Brush Settings: #1: 7.1 (UP)
• • Temperature: 270° F.
  • Speed: 15 ypm
  • Entry Rail Setting: 64″, Exit Rail Setting: 66″
• Dyed: 266° F. for 30 minutes, using disperse dyes, with a rate of temperature rise of 2° F./min.
• Selective Application of Shrinkage: Heated air (i.e., Millitex®) on fabric face
• • Temperatures: 340° F.
  • Speed: 0.6 ypm
  • Heated air pressure: 3.5 psi
  • Blocking air pressure: 15 psi
• Results: The polypropylene yarns receded into the ground due to their lower melting point, while the acetate fibers remained in the pile to achieve a two-color pattern effect resembling the visual effect achieved with other thermoplastic fibers (e.g., polyester and nylon).
• The following is a description of one means, disclosed in the prior art, by which pattern-wise selective shrinkage of the kind discussed above may be imparted to various pile fabrics through the use of a plurality of individually controlled heated air streams.
• FIG. 5 shows, diagrammatically, an overall side elevation view of apparatus for heated, pressurized gas stream treatment of atextile fabric10. This apparatus may be used to melt the second,lower melt fibers7 within a selected area, perhaps comprising a pattern, and retain the first, higher melt fibers8 in that same area so that the color of the first, higher melt fibers8 may dominate in these select areas and the combined resulting color from the combination of the first, higher melt fibers8 and the second,lower melt fibers7 may dominate in the remaining untreated areas.
• As seen, the apparatus includes a main support frame including end frame support members, one of which110 is illustrated inFIG. 5. Suitably rotatably mounted on the end support members of the frame are a plurality of textile fabric guide rolls which direct an indefinite length oftextile fabric10 from afabric supply roll118, past a pressurized, heated gas treating unit, generally indicated at116. After treatment, thetextile fabric10 is collected in a continuous manner on a take-up roll114.
• As shown,textile fabric10 fromsupply roll118 passes over anidler roll136 and is fed by a pair of drivenrolls134,132 to a main driven textilefabric support roll126 with thetextile fabric10 betweendrive roll132 and textilefabric support roll126 being overfed and slack, with a negative tension within a range of between two and twenty percent and within a preferred range of between two and twelve percent. The amount of negative tension or overfeed depends on the construction, fiber type, and other factors related to thetextile fabric10. The overfeed or negative tension must stop before the point at which puckering of thetextile fabric10 occurs. The surface of thetextile fabric10 passes closely adjacent to the heated fluid discharge outlet of an elongate fluid distributingmanifold assembly130 of treatingunit116. The treated textile fabric4 thereafter passes over a series of driven guide rolls122,124 and anidler roll120 to a take-up roll114 for collection.
• As illustrated inFIG. 5,fluid treating unit116 includes a source of compressed gas, such as anair compressor138, which supplies pressurized air to an elongateair header pipe140.Header pipe140 communicates, by a series ofair lines142 spaced uniformly along its length, with a bank of individual electrical heaters indicated generally at144. Theheaters144 are arranged in parallel along the length of heated fluid distributingmanifold assembly130 and supply heated pressurized air thereto through short, individual air supply lines, indicated at146, which communicate withassembly130 uniformly along its full length. Air supplied to the heated fluid distributingmanifold assembly130 is controlled by amaster control valve148,pressure regulator valve149, and individual precision control valves, such asneedle valves150, located in each heaterair supply line142. Theheaters144 are controlled in suitable manner, as by temperature sensing means located in theoutlet lines146 of each heater, with regulation of air flow and electrical power to each of the heaters to maintain the heated fluid at a uniform temperature and pressure as it passes into the manifold assembly along its full length.
• Typically, for patterning textile fabrics, such as pile fabrics containing thermoplastic yarns, the heaters are employed to heat air exiting the heaters and entering the manifold assembly to a uniform temperature. The preferred operating temperature for any given textile fabric depends upon many factors, including the components of the textile fabric, the desired amount of linear shrinkage or melting effect, the speed of transport of the textile fabric, the pressure of the heated pressurized gas, the tension of the textile fabric, the proximity of the textile fabric to the treating manifold, and other factors. For a needle punched, textile fabric where the first fiber is polyester and the second fiber is polypropylene, the temperature can range between 300° Fahrenheit to 1,200° Fahrenheit with a more practical operating range of 375° Fahrenheit to 800° Fahrenheit and a preferred optimal range of 450° Fahrenheit to 500° Fahrenheit. This preferred optimal range will maximize the contrast between the color of the first, higher melting point fibers and the blend of higher and lower melting point fibers.
• The heated fluid distributingmanifold assembly130 is disposed across the full width of the path of movement of the textile fabric and closely adjacent to the surface to be treated. Although the length of themanifold assembly130 may vary, typically in the treatment of textile fabric materials, the length of the manifold assembly may be 76 inches or more to accommodate textile fabrics of up to about 72 inches in width.
• Details of the heated fluid distributingmanifold assembly130 may be best described by reference toFIGS. 6, 7, and8 of the Drawings. As seen inFIG. 6, which is a partial sectional elevation view through the assembly, there is a first large elongatemanifold housing154 and a second smaller elongatemanifold housing156 secured in fluid tight relationship therewith by a plurality of spaced clamping means, one of which is generally indicated at158. Themanifold housings154,156 extend across the full width of thetextile fabric10 adjacent its path of movement.
• As best seen inFIG. 6, first elongatemanifold housing154 is of generally rectangular cross-sectional shape, and includes a first elongategas receiving compartment181, the ends of which are sealed by end wall plates suitably bolted thereto. Communicating with bottom wall plate through fluid inlet openings, one of which,183, is shown inFIG. 6, and spaced approximately uniformly therealong are theair supply lines146 from each of theelectrical heaters144.
• Themanifold housings154,156 are constructed and arranged so that the flow path of gas through thefirst housing154 is generally at a right angle to the discharge axes of the gas stream outlets of the secondmanifold housing156.
• As best seen inFIGS. 6 and 7,manifold housing154 is provided with a plurality ofgas flow passageways186 which are disposed in uniformly spaced relation along the plate in two rows to connect the firstgas receiving compartment181 with a centralelongate channel188.
• Baffle plate192 serves to define a gas receiving chamber in thecompartment181 having side openings orslots194 to direct the incoming heated air from the bank of heaters in a generally reversing path of flow throughcompartment181. Disposed above channel-shapedbaffle plate192 iscompartment181 and between thefluid inlet openings183 andfluid outlet passageways186 is anelongate filter member200 which is a generally J-shaped plate, with a filter screen disposed thereabout.
• As seen inFIGS. 6, 7 and8, a second smallermanifold housing156 comprises first and second opposed elongate wall members, each of which has an elongate recess orchannel208 therein. Wall members are disposed in spaced, coextensive parallel relation with theirrecesses208 in facing relation to form upper and lower wall portions of a secondgas receiving compartment210 in the secondmanifold housing156. The gas then passes through a thirdgas receiving compartment212 in the lower wall member ofmanifold housing156, which is defined by smallelongate islands211 approximately uniformly spaced along the length of the member, as shown inFIG. 8. A continuous slit directs heated pressurized air from the thirdgas receiving compartment212 in a continuous sheet across the width of the fabric at a substantially right angle onto the surface of the movingtextile fabric10. Typically, in the treatment of textile fabrics such as pile fabrics containing thermoplastic fiber components, thecontinuous slit215 ofmanifold156 may be 0.015 to about 0.030 of an inch in thickness. For precise control of the heated air streams striking thetextile fabric10, the continuous slit is preferably maintained between about 0.070 to 0.080 of an inch from the textile fabric surface being treated. However, this distance from the face of the textile fabric can be as much as 0.100 of an inch and still produce good pattern definition. The deflectingair tubes226 are spaced twenty (20) to the inch over the seventy-two (72) inch air distributing manifold, although the apparatus has been constructed with spacings ranging from ten (10) to the inch to forty-four (44) to the inch.
• Secondmanifold housing156 is provided with a plurality of spaced gas inlet openings218 (FIGS. 6 and 7) that communicate with theelongate channel188 of the firstmanifold housing154 along its length to receive pressurized, heated air from the firstmanifold housing154 into the secondgas receiving compartment210.
• Thecontinuous slit215 of the secondmanifold housing156 which directs a stream of air into the surface oftextile fabric10 is provided withtubes226 which communicate at a right angle to the discharge axis ofcontinuous slit215 to introduce pressurized cool air, i.e., air having a temperature substantially below that of the heated air in thirdgas receiving compartment212, at the heatedgas discharge outlet216 to deflect selectively the flow of heated air through thecontinuous slit215 in accordance with pattern control information. Air passing through thetubes226 may be cooled by a water jacket which is provided with cooling water from a suitable source, not shown, although such cooling is not required.
• As seen inFIG. 5, pressurized unheated air is supplied to each of thetubes226 fromcompressor138 by way of amaster control valve228,pressure regulator valve229,air line230, and unheatedair header pipe232, which is connected by a plurality of individualair supply lines234 to theindividual tubes226. Each of the individual coolair supply lines234 is provided with an individual control valve located in avalve box236. These individual control valves are operated to open or close in response to signals from a pattern control device, such as acomputer238, to deflect the flow of hot air throughcontinuous slit215 during movement of thetextile fabric10 and thereby produce a desired pattern in thetextile fabric10. Detailed patterning information for individual patterns may be stored and accessed by means of any known data storage medium suitable for use with electronic computers, such as magnetic tape, EPROMs, etc.
• The foregoing details of the construction and operation of themanifold assembly130 of the gas treating apparatus are the subject matter of commonly assigned U.S. Pat. No. 4,471,514 issued on Sep. 18, 1984 and U.S. Pat. No. 5,035,031 issued on May 18, 1993. The disclosures thereof are included herein by reference as if fully set forth herein.
• Each cool airfluid tube226 is positioned at approximately a right angle to the plane defined byslit215 to deflect heated pressurized air away from the surface of the moving textile fabric10 (FIG. 6) as the textile fabric approachescontinuous slit215. This deflection is generally at about a forty-five (45) degree angle from the path defined bycontinuous slit215, and serves to direct the deflected heated air toward theoncoming textile fabric10. Thus, a strong blast of mixed hot and cold air strikes the surface of the textile fabric prior to its being subjected to the action of the heated air issuing fromcontinuous slit215.
• This configuration oftubes226 provides sufficient volume of air, in combination with that from thecontinuous slit215, to preheat thetextile fabric10 to a temperature preferably below that which causes permanent thermal modification.
• It should be noted that, due to theinsulation108 generally surroundingmanifold154, preheating is not believed to be the result of heat radiation from the manifold, but is rather the result of the exposure oftextile fabric10 to the heated air issuing fromcontinuous slit215, as that air is diverted by the relatively cool air issuing fromtubes226. The heated air used for this purpose is air that has been diverted, in accordance with patterning instructions, after issuing fromcontinuous slit215, i.e., this air would be diverted whether or not preheating was desired. Therefore, preheating of the textile fabric is achieved as an integral part of, and is inseparable from, the patterning process, and requires no additional or separate heated air source. By so doing, not only is a separate preheating step and its attendant complexity unnecessary, but it is believed a separate preheating step would be incapable of imparting heat of sufficient intensity and directivity to maintain thetextile fabric10 at an effective preheated temperature at the instant the heated patterning air issuing fromcontinuous slit215 contacts the textile fabric, as shown inFIG. 8.
• This preheating may cause additional thermal modification during the patterning step. As can be seen in connection withFIG. 9, the amount of shrinkage is a function of the type of fiber involved and the temperature to which it is subjected. The temperature of the hot air is adjusted to accommodate a particular fiber so that the amount of shrinkage can be controlled regardless of the fiber composition of the fabric. The air pressure of the heated gas can range between 0.5 to 10 pounds per square inch, with a more practical operating range of 1 to 5 pounds per square inch and a preferred optimal range of 1 to 3 pounds per square inch. The air pressure of the cooler, blocking gas can range between 2 to 18 pounds per square inch, with a more practical operating range of 9 to 18 pounds per square inch and a preferred optimal range of 10 to 12 pounds per square inch. The speed of transport of the moving textile web can range between 1 to 25 yards per minute, with a more practical operating range of 3 to 18 yards per minute and a preferred optimal range of 6 to 10 yards per minute.
• Additional information relating to the operation of such a pressurized, heated gas apparatus, including more detailed description of patterning and control functions, can be found in the following commonly-assigned issued U.S. Patents, the content of which are expressed incorporated by reference herein: U.S. Pat. Nos. 5,148,583 4,393,562 4,364,156, and 4,418,451.
• In the alternative, another means of achieving the selective linear shrinking or melting of certain pile yarns is to subject the pile yarns to the heat of a laser. Referring now toFIG. 10, which shows, diagrammatically, an overall side elevation view of apparatus for laser treatment of atextile fabric10 to impart lateral yarn displacement. There is a plurality of textile fabric guide rolls which direct an indefinite length oftextile fabric10 from afabric supply roll302 and past a laser unit, indicated bynumeral320. After treatment, the treated textile fabric4 is collected in a continuous manner on a take-up roll316. As shown,textile fabric10 fromsupply roll302 passes over anidler roll306 to a main driven textilefabric support roll308. The surface of thetextile fabric10 is hit by the laser beam fromlaser unit320 betweenidler roll306 and drivenroll308. The treated, textile fabric4 thereafter passes over a series of driven guide rolls312,314 and then to take-up roll316 for collection.
• Laser unit320 is preferable a 10.6 micron wavelength, eighty watt, carbon dioxide laser, although any of a wide variety of lasers will suffice. One typical laser of this type is manufactured by Laser Machining, Inc., located at 500 Laser Drive, MS 628, Industrial Park, Somerset, Wis. 54025. Although not specifically limited thereto, the preferred speed range for moving thetextile fabric10 is one hundred to two hundred inches per minute.
• Other methods of selectively applying heat for selective shrinkage or melting include an infrared heater tube, microwaves, or other appropriate means of selectively applying heat by means of either convection or radiation.
• As this invention may be embodied in several forms without departing from the spirit or essential character thereof, the embodiments presented herein are intended to be illustrative and not descriptive. The scope of the invention is intended to be defined by the following appended claims, rather than any descriptive matter hereinabove, and all embodiments of the invention which fall within the meaning and range of equivalency of such claims are, therefore, intended to be embraced by such claims.

Claims (33)

1. A process for generating patterns in a textile pile fabric comprising the steps of:

(a) creating a textile pile fabric having a plurality of individual pile-like yarns, each of said pile-like yarns being comprised of a first type of component yarn having a first set of aesthetic characteristics and a first shrinkage characteristic that causes said first type of component yarn, as a result of exposure to a shrinking agent, to exhibit relatively low shrinkage, and a second type of component yarn, lengthwise coupled with said first type of component yarn, having a second set of aesthetic characteristics and a second shrinkage characteristic that causes said second type of component yarn, as a result of similar exposure to said shrinking agent, to exhibit greater shrinkage than said first type of component yarn, wherein at least one of said component yarn types is texturized;

(b) applying a shrinkage agent to said pile fabric, thereby inducing shrinkage in said component yarns comprising said individual pile-like yarns, said shrinkage of said first type of component yarns within a given pile-like yarn being less than said shrinkage of said second type of component yarns within said given pile-like yarn as a result of exposure to said shrinkage agent, said shrinkage causing said second type of component yarns to shorten and recede in the direction of said fabric ground to a greater extent than said first type of component yarns and enhancing the visual contribution of the aesthetic characteristics of said first type of component yarns relative to the aesthetic characteristics of said second type of component yarn;

(c) subjecting said pile fabric to a dyeing step.

2. The process ofclaim 1 wherein said dyeing step occurs prior to the application of said shrinkage agent.

3. The process ofclaim 1 wherein said dyeing step involved the selective application of dye to said fabric in a pattern configuration.

4. The process ofclaim 2 wherein said dyeing step involved the selective application of dye to said fabric in a pattern configuration.

5. The process ofclaim 1 wherein said shrinkage agent is applied only in selected areas of said pile fabric in accordance with electronically defined pattern data.

6. The process ofclaim 5 wherein said shrinkage agent is applied in registry with a pre-determined pattern to be applied to said pile fabric.

7. The process ofclaim 5 wherein said shrinkage agent is applied in registry with a pre-existing pattern on said pile fabric.

8. The process ofclaim 5 wherein said shrinkage agent is heat.

9. The process ofclaim 5 wherein said shrinkage agent is comprised of a plurality of pressurized, heated gas streams directed at said pile fabric.

10. The process ofclaim 9 wherein said gas streams are selectively interrupted in accordance with pattern information in order to cause localized shrinkage of said second type of component yarns only in pile-like yarns within areas defined by said pattern.

11. The process ofclaim 9 wherein said gas streams are directed at the face of said pile fabric.

12. The process ofclaim 1 wherein the primary constituent of said first type of component yarns is selected from the group consisting of polyester, nylon, and cellulosic fibers.

13. The process ofclaim 1 wherein the primary constituent of said second type of component yarns is selected from the group consisting of polypropylene, polyester, and nylon.

14. The process ofclaim 1 wherein said second type of component yarns are comprised of solution dyed polypropylene.

15. The process ofclaim 1 wherein said first type of component yarns are commingled with said second type of component yarns.

16. The process ofclaim 1 wherein said first type of component yarns are selected from the group consisting of polyester, nylon, and rayon fibers and wherein said shrinkage agent is comprised of a plurality of pressurized, heated gas streams, said gas streams having been heated to a temperature within the range of about 300° F. to about 460° F. and directed onto the face of said pile fabric.

17. The process ofclaim 1 wherein said first type of component yarns are selected from the group consisting of polyester, nylon, and rayon fibers and wherein said shrinkage agent is comprised of a plurality of pressurized, heated gas streams, said gas streams having been heated to a temperature within the range of about 550° F. to about 590° F. and directed onto the back of said pile fabric.

18. The process ofclaim 16 wherein said gas streams have been heated to a temperature within the range of about 350° F. to about 460° F.

19. The process ofclaim 16 wherein gas streams, heated to a temperature within the range of about 550° F. to about 590° F., are also directed onto the back of said pile fabric.

20. A process for forming a multicolored pile fabric comprising the steps of:

(a) creating a textile pile fabric having a plurality of individual pile-like yarns, each comprised of a first type of component yarn comprised of package dyed polyester having a first set of color and light reflectivity characteristics, said dyed polyester yarn having shrinkage characteristics that causes it to exhibit relatively low shrinkage as a result of exposure to heated air streams having a temperature between about 350° F. and about 460° F., and a second type of component yarn, physically associated with said first type of component yarn, comprised of solution dyed polypropylene having a second set of color and light reflectivity characteristics, said polypropylene yarn having shrinkage characteristics that causes it to exhibit greater shrinkage than said polyester component yarn as a result of similar exposure to heated air streams having a temperature between about 350° F. and about 460° F.

(b) applying a plurality of heated air streams having a temperature between about 350° F. and about 460° F. to the face of said pile fabric, thereby inducing shrinkage in said component yarns comprising said pile-like yarns, said shrinkage of said polyester component yarns being less than said shrinkage of said polypropylene component yarns as a result of exposure to said heated air streams, said shrinkage causing said polypropylene component yarns to shorten and recede in the direction of said fabric ground to a greater extent than said polyester component yarns and visually enhancing the relative contribution of the set of color and light reflectivity characteristics of said polyester component yarns relative to the overall appearance of the pile fabric.

21. The process ofclaim 20 wherein the relative contributions of the respective colors of said polyester and said polypropylene component yarns combine visually to form a third color in areas of the pile fabric.

22. The process ofclaim 20 wherein said polyester component yarns are comprised of textured polyester and wherein said polypropylene yarns are flat and unentangled with said textured polyester yarns, wherein the combination of the respective colors of said textured polyester and said polypropylene component yarns, and the relative light reflectivity of said polypropylene component yarns, combine visually to form iridescent areas on the pile fabric.

23. A textile pile fabric having a plurality of individual pile-like yarns, at least some of which are comprised of a first type of component yarn having a first set of aesthetic characteristics and a first shrinkage characteristic that causes said first type of component yarn, as a result of exposure to a shrinking agent, to exhibit relatively low shrinkage, and a second type of component yarn, physically associated with said first type of component yarn, having a second set of aesthetic characteristics and a second shrinkage characteristic that causes said second type of component yarn, as a result of similar exposure to said shrinking agent, to exhibit greater shrinkage than said first type of component yarn, wherein at least one of said first type and said second type of component yarns is textured, and wherein said individual pile-like yarns of said fabric are comprised of component yarns of the first type that exhibit relatively low shrinkage and component yarns of the second type that exhibit greater shrinkage than said first type of component yarns.

24. The fabric ofclaim 23 wherein said linear shrinkage of said first type of component yarn is less than about 6%, and the linear shrinkage of said second type of component yarn is greater than about 20%.

25. The fabric ofclaim 23 wherein said melting point of said first type of component yarn is within the range of about 480° F. and about 500° F., and the melting point of said second type of component yarn is within the range of about 300° F. and about 320° F.

26. The fabric ofclaim 23 wherein said shrinkage of said first type of component yarn is less than about 3%, and the shrinkage of said second type of component yarn is greater than about 15%.

27. The pile fabric ofclaim 23 in which said pile-like yarns are comprised of at least two component yarns, one of which is solution-dyed polypropylene and the other of which is textured polyester.

28. The fabric ofclaim 23 wherein substantially all of said pile-like yarns comprising said pile fabric are comprised of component yarns that have been shrunken to some degree.

29. The pile fabric ofclaim 23 in which said pile-like yarns are comprised of at least three component yarns, one of which is flat solution-dyed polypropylene and the other of which is selected from the group consisting of piece-dyed and package-dyed polyester.

30. The fabric ofclaim 23 wherein said pile fabric contains first areas in which substantially all of said pile-like yarns comprising said pile fabric are comprised of component yarns that have been shrunken to some degree, and also contains second areas in which substantially all of said pile-like yarns are comprised of component yarns that remain substantially unshrunken.

31. The pile fabric ofclaim 30 in which said first areas are configured in accordance with a pre-determined pattern.

32. The pile fabric ofclaim 30 in which at least some of said first areas correspond to, and are substantially in registry with, areas in which component yarns have been dyed in accordance with a pre-determined pattern.

33. A textile fabric having a pile face and an fabric back, said pile face being comprised of a plurality of individual pile-like yarns, each comprised of a first type of component yarn comprised of package dyed textured polyester having a first set of color and light reflectivity characteristics and a second type of component yarn, physically associated with said first type of component yarn, comprised of solution dyed polypropylene having a second set of color and light reflectivity characteristics, wherein said polypropylene component yarn has a lower melting point that causes it to exhibit greater shrinkage than said polyester component yarn, said lower melting point causing, upon exposure to heat in a plurality of individual pile-like yarns, said polypropylene component yarn to shorten and recede in the direction of said fabric back to a greater extent than said polyester component yarn and visually enhancing the relative contribution of the set of color and light reflectivity characteristics of said polyester component yarn in said plurality of pile-like yarns relative to the overall appearance of the pile fabric.

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