Yarn having differentiated shrinkage segments and fabrics formed therefrom
A multi-filament yarn including interlace nodes disposed along the length of the yarn. The yarn has variable retained heat shrinkage potential at segments along its length such that segments of said yarn containing the interlace nodes have a retained heat shrinkage potential in excess of segments of said yarn between the interlace nodes. Upon application of uniform heat to the yarn, the segments containing the interlace nodes exhibit enhanced shrinkage and self texturing relative to the segments between the interlace nodes. A fabric formed with the yarn prior to the final heating process will present a varied and random appearance after application of the final heating process due to the differentiated shrink segments. Pile fabrics formed with the yarn as the pile yarn prior to the final heat treatment will have piles of varying height due to the differentiated shrink segments, and will also have a varied or random appearance.
This application is a continuation-in-part of prior co-pending U.S. application Ser. No. 10/613,240, filed Jul. 3, 2003, entitled “Pile Fabric and Heat Modified Fiber and Related Manufacturing Process”, and a continuation-in-part of prior co-pending U.S. application Ser. No. 10/613,241, filed Jul. 3, 2003, entitled “Method of Making Pile Fabric”, and a continuation-in-part of prior co-pending U.S. application Ser. No. 10/835,772, filed Apr. 30, 2004, entitled “Loop Pile Fabric Having Randomly Arranged Loops of Variable Height”, and a continuation-in-part of prior co-pending U.S. application Ser. No. 10/835,763, filed Apr. 30, 2004, entitled “Textile Fabric Having Randomly Arranged Yarn Segments of Variable Texture and Crystallinity”, and a continuation-in-part of prior co-pending U.S. application Ser. No. 10/835,773, filed Apr. 30, 2004, entitled “Yarn Having Variable Shrinkage Zones”, the contents of all of which are incorporated by reference herein in their entirety.
TECHNICAL FIELDThe present invention relates generally to fabric formation yarns and more particularly to multifilament yarns in which discrete segments along the length undergo enhanced selective shrinkage resulting in self texturing and reduced crystalline orientation relative to other portions of the same yarn. The present invention also relates to various fabrics formed with the multifilament yarns having discrete segments of differing shrinkage.
BACKGROUND OF THE INVENTIONIn the past, partially oriented yarns (POY) of multi-filament construction have typically been drawn and heatset under tension so as to extend and orient the individual filaments. In such a process each of filaments in the yarn is subjected to a substantially uniform heating and extension treatment such that the yarn will thereafter act in a uniform manner upon post fabric formation treatments such as heat setting, dyeing and the like. That is, since the yarn has been uniformly treated it does not exhibit variable response characteristics in a fabric when subjected to heating or other treatment conditions.
It is also known to under draw yarns under uniform heat treatment to less than full orientation for subsequent formation into a fabric. Such a process is illustrated and described in U.S. Pat. No. 5,983,470 to Goineau the contents of which are incorporated herein by reference in their entirety. The resultant fabric has a generally striated appearance upon dyeing.
SUMMARY OF THE INVENTIONAccording to one aspect, the present invention provides advantages and alternatives over the known art by providing a fabric formation yarn having variable shrink characteristics at different segments (also referred to as zones) along its length such that when such yarn is subsequently subjected to heat such as in fabric finishing treatments, discrete portions of the yarn undergo selective shrinkage and self texturing. The shrinking of segments along the yarn yields unshrunken yarn segments of substantially parallel, oriented fibers in combination with shrunken yarn segments of self textured filaments with reduced crystalline orientation in the same yarn.
According to another aspect, the present invention incorporates the yarn having differentiated segment shrink characteristics into a knit fabric so that when the fabric is subjected to a heat treatment, such as heated finishing and/or dyeing at elevated temperature, discrete portions of the yarn shrink preferentially thereby tightening up sections of the looped underlaps. This tightening causes the portions of the yarn which do not shrink to become raised in the fabric face. The shrinking of segments along the surface-forming yarn yields substantially random arrangements of unshrunken yarn segments of substantially parallel fibers in combination with shrunken yarn segments of self textured filaments with reduced crystalline orientation in the same yarn. The resultant fabric has an irregular surface appearance and surface texture.
According to yet other aspects, the present invention utilizes the yarn having differentiated segment shrink characteristics as the loop pile yarns in a loop pile fabric and the cut pile yarns in a cut pile fabric. The pile yarn has variable shrink characteristics at different zones along its length such that when the pile-forming yarn is introduced into a loop pile fabric and is thereafter subjected to heated finishing treatments, discrete portions of the yarn shrink towards the base of the fabric. The shrinking of zones along the pile-forming yarn towards the fabric base yields substantially random arrangements of unshrunken high pile zones in combination with shrunken lower pile zones of self textured crimped filaments with reduced crystalline orientation in the same yarn. The resultant fabric has an irregular pebble appearance.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will now be described by way of example only, with reference to the accompanying drawings which constitute a portion of the specification herein and wherein:
While the present invention has been generally described above and will hereinafter be described in greater detail in relation to certain illustrated and potentially preferred embodiments, procedures and practices it is to be understood that in no event is the invention to be limited to such illustrated and described embodiments, procedures and practices. Rather, it is intended that the invention shall extend to all embodiments, practices and procedures as may be embodied within the broad principles of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTSYarns With Segmented Differential Shrinkage Potential
Referring to
As shown, the drawing apparatus 32 has a first draw zone 36 located between tensioning rolls 38, 40 and a second draw zone 42 located between tensioning rolls 40 and 46. A contact heating plate 50 as will be well known to those of skill in the art engages the yarns 100 within the second draw zone 42. According to the potentially preferred practice, the partially oriented yarns 100 are passed through the first draw zone 36 with substantially no heating or drawing treatment. Thus, the yarns 100 are substantially unaltered upon entering the second draw zone 42. At the second draw zone the yarns 100 preferably undergo a relatively slight drawing elongation while simultaneously being subjected to a relatively low temperature heating procedure from the contact heater 50. Since the resultant yarn 100′ is not drawn to a condition of full orientation it is referred to as “underdrawn” yarn. By “underdrawn”, it is meant that the fiber is still partially oriented and has a residual elongation of at least about 40%.
However, the resultant yarn 100′ of the present invention differs from a typical “underdrawn” yarn. According to the potentially preferred practice the yarn 100 is conveyed across the contact heater 50 at a high rate of speed such that the yarn does not reach a state of temperature equilibrium within the cross-section of the yarn at all segments along its length. As a consequence, the resultant yarn 100′ has discrete segments along its length that have been heatset to a greater extent than other segments. The segments of the resultant yarn 100′ that have a different extent of heat history will also have a different potential of shrinkage when heat is applied to the resultant yarn 100′.
By way of example only, and not limitation, for a 115 denier polyester yarn it has been found that subjecting such yarn to a draw ratio of about 1.15 (i.e. 15% elongation) with a contact heater temperature of about 170 C to about 200 C with a take up speed of about 600 yards per minute provides the desired non-uniform cross-sectional heat treatment at some segments of the yarn while yielding a uniform cross-sectional heat treatment at other segments. Of course, the level of drawing, temperature and speed may be adjusted for different yarns.
The mechanism believed to be responsible for the non-uniform character of the resultant yarns 100′ is believed to relate to the nature of the partially oriented yarn 100 being processed as well as the process conditions. Referring to
In
It is surmised that due to the lack of flattening and the high rate of travel across the heater, heat treatment is not uniform within the interlace nodes and adjacent portions. Thus, a significant number of the filaments at those areas retain a relatively high level of shrinkage potential since a steady state temperature is not reached. The retention of such shrinkage potential leaves such segments susceptible to subsequent enhanced heat shrinkage relative to the remaining portions of the yarn (which have been subjected to uniform temperature treatment) upon subsequent heat application.
By way of example only, within a yarn 100′ according to the present invention it is contemplated that the number of interlace nodes will preferably be in the range of about 8 to 40 nodes per meter with each node taking up about 0.6 to about 1.3 cm. Thus, it is contemplated that zones of high retained shrinkage potential will preferably make up about 4.8% to about 52% percent of the total length of the yarn and will more preferably make up about 25% of the total length of the yarn.
The resultant yarn 100′ may then be formed into a fabric and heat treated to provide desired surface characteristics in the manner as will be described further hereinafter. Of course, it is also contemplated that the resultant yarn 100′ may be subjected to heat treatment prior to introduction into a fabric if desired. In either case, particular discrete segments of the yarn 100′ undergo shrinkage and self-texturing during subsequent heating of the resultant yarn 100″ while other segments along the same yarn experience little if any change.
Variable Shrinkage and Bulking
The enhanced retained shrinkage potential of the resultant yarn 100′ at the interlace nodes relative to the intermediate loose zones following the treatment process as outlined above has been confirmed by cutting out segments of an exemplary 260 denier polyester yarn treated according to the procedure outlined above and thereafter subjecting those cut out segments to a uniform heat treatment and then measuring the level of shrinkage caused by the heat treatment. In particular, a first group of two yarn segments was cut out from sections between interlace nodes such that each of the two cut out yarn segments in this first group was substantially devoid of any interlace node. A second group of three yarn segments was cut out from the yarn such that each of the three cut out yarn segments in this second group was formed substantially of a single interlace node. Both the first group and the second group of yarn segments were then subjected to a high temperature superheated steam treatment to observe shrinkage. The results are set forth in Table I below showing that the second group of yarn segments formed from the interlace nodes exhibited substantially increased shrinkage on a percentage basis relative to the yarn segments in the first group devoid of interlace nodes.
In addition to shrinkage, it was also observed that the yarn segments formed from the interlace nodes of the resultant yarn 100′ underwent an enhanced degree of bulking and self texturing when subjected to post treatment heating, resulting in substantial filament thickening in a significant portion of the filaments. In this regard it is to be understood that the terms “self texturing” or “self-crimping” refers to the characteristic that the filaments have a crimped construction after shrinkage without the application of external crimping or texturizing procedures. It was also discovered that the shrinkage and self texturing of those sections of yarn caused the cross section in those sections of the yarn to enlarge.
By way of example only, for purposes of comparison photomicrographs are provided of filament cross sections in exemplary low shrink yarn portions (
Crystalline Orientation
It has also been found that after heat treatment (such as occurs in fabric finishing) segments of the same resultant yarn 100′ treated according to the procedures as previously described are characterized by substantially different levels of crystalline orientation as measured by wide angle x-ray diffraction. In order to characterize the molecular structure of the two different types of domains in a finished construction, a polyester yarn treated according to the process as illustrated and described in relation to
To understand the differences in the zones of the sock individual courses of each type of region were removed from the construction for x-ray measurement. Courses were ‘double-folded’ to form a 4-ply yarn so as to increase the scattering signal rate and reduce the necessary exposure time. Samples were mounted onto standard x-ray sample mounts.
Wide-angle diffraction patterns were generated via exposure to x-rays generated with a rotating copper anode source having a primary wavelength of 1.5418 Å. Patterns were recorded using a general area detector system offset to an angle of 2=16.5° and set 15 cm from the sample position. Samples were oriented in the beam such that the fiber axis was vertical. Exposures of 15 minutes were used to generate patterns, and a background pattern acquired over an empty position on the sample holder was subtracted from the resulting data.
The diffraction pattern for the high-shrink yarn sample is shown in
It is known that the difference in the angular distribution of crystallites between the two samples can be quantified in terms of the Herman orientation function:
where σ is the relative angle of the PET chain axis. As will be appreciated, the Herman orientation function is a measure of the orientation of PET chains within fiber crystallites with respect to the fiber axis direction. It assumes values ranging from +1 (perfectly oriented parallel to the axis) to 0 (perfectly random) to −{fraction (1/2)} (perfectly oriented perpendicularly). For cylindrically symmetric (on average) fibers, the distributional average of the square cosine term is given by:
Where /p(λ) is the angular distribution of a directional vector P (in this case, the PET chain direction) as measured with respect to a reference direction, in this case the fiber axis.
In PET there does not exist a crystalline reflection in the direction of the PET chains. Thus, to determine the Herman orientation function for PET chains a well recognized geometric relationship is utilized to develop the square cosine term.
cos2σ=1−0.8786cos2λ(010)−0.7733cos2λ(110)−0.348cos2λ(100),
where σ is the relative angle of the PET chain axis, and λ(hk0) are the relatives angles of the (hk0) crystalline reflections. This relationship was described by Z. Wilchinsky in Journal of Applied Physics 30, 792 (1959) the contents of which are incorporated herein by reference.
The <cos2λ(hk0)> terms can be numerically computed by extracting the /(hk0)(λ) distributions from the measured diffraction patterns. Angular distributions were computed by integrating the pattern signals over a 0.7° range of 2{circle over (-)} values centered on the following positions: 17.65° for the (010) reflection, 22.75° for the (110) reflection, and 25.35° for the (100) reflection. Distributions of x-ray peaks for the high shrink and low shrink yarn segments (used for purposes of integration) are shown in
Results from the numerical determination of the Herman orientation function (fc) are shown in Table II below. As shown, the low-shrink yarn sample possessed a measurably higher level of orientation.
In order to confirm the legitimacy of the crystalline orientation evaluations on the treated yarn of the present invention, a control analysis was conducted on a standard fully drawn 265 denier 36 filament partially oriented PET yarn that had been cold drawn with a 2.1 draw ratio and heat set at 220° C. Three samples were taken from segments 6 to 12 inches apart along the length of the yarn and x-ray patterns were generated using 45 minute exposures. An air scattering frame was also acquired and subtracted from the data before analysis. The same calculations were performed as described above. The Herman orientation function calculated based on the measurements of these samples ranged from 0.819 to 0.853 which is a difference of 0.034. This is less than half the difference of 0.074 measured for the high shrink and low shrink portions of the yarn. Thus, there exists a much greater variation in crystalline orientation between portions of the yarns of the present invention following heat treatment than in standard yarns.
Based on the evaluations carried out it may be seen that the interlaced nodes along the yarn give rise to the high shrink portions of the yarn. Moreover, upon application of heat treatment these high shrink portions shrink to a greater degree and have a lower level of crystalline orientation (as measured by the Herman Orientation Function) than the low shrink portions. Moreover, the degree of variation in crystalline orientation along the length of the yarns of the present invention is substantially greater than variations in standard yarns.
Fabric Formation
In
Flat Fabric
In
As will be appreciated through reference to
As will be appreciated, the heating may be carried out as a heat treatment during finishing, as an elevated dyeing treatment or any such other suitable elevated temperature operation as may be desired. As shown in
As in the individual yarn samples evaluated, due to the differentiated shrinkage of the filaments at different yarn segments in the fabric, the filaments within the self textured segments 306 of the face are characterized by a substantially greater diameter than the filaments in the unaltered surface loops 305 and a different crystalline orientation, as previously described. By way of example only, for purposes of comparison refer to the photomicrographs of filament cross sections in exemplary low shrink yarn portions illustrated in
By way of example only, within a resultant yarn 100′ according to the present invention it is contemplated that the number of interlace nodes will preferably be in the range of about 8 to 40 nodes per meter with each node taking up about 0.6 to about 1.3 cm. Thus, it is contemplated that zones of high retained shrinkage potential will preferably make up about 4.8% to about 52% percent of the total length of the yarn and will more preferably make up about 25% of the total length of the yarn.
As previously indicated, a substantial benefit of the present invention is that the self-textured segments of heat shrunk yarn are present across the surface of the fabric in a substantially random arrangement. This imparts a substantially natural random look which may be desirable in many instances. Moreover, since the self-textured zones undergo heat shrinkage as a result of activating intrinsic heat shrink potential, such shrinkage occurs without embrittlement thereby enhancing a soft feel and avoiding filament breakage leading to undesirable shredding. Also as previously indicated, after self-texturing takes place, the high shrink portions of the yarn have a lower level of crystalline orientation than the low shrink portions. In this regard it is contemplated that the level of crystalline orientation of the low shrink portions of the yarn as measured by the Herman Orientation Function will on average be at least 5% greater (and more preferably at least 10% greater) than the level of crystalline orientation of the high shrink portions.
The invention may be further understood through reference to the following non-limiting examples:
EXAMPLE IA 115 denier 36 filament semi-dull round partially oriented polyester yarn was subjected to a 1.143 draw across a contact Dowtherm heater plate operated at a temperature of 200° C. The heater contact length was 17 inches and the yarn was taken up off of the heater at a rate of 600 yards per minute. The yarns were spaced at a density of approximately 17.4 yarns per inch across the heater. The warper tension was set at 25 to 30 grams. Overall draw ratio was 1.165. Measurements of the post drawn yarn indicated a linear density of 100.5 denier and a boiling water shrinkage of 10.0%. The drawn yarn was knitted into the face of a 2 bar Tricot knit fabric with the ground being formed of a 70 denier 36 filament semi-dull round fully warpdrawn polyester. The bar 1 (face yarn) runner length was 102 inches. The bar 2 (ground yarn) runner length was 46 inches. The knitting machine was fully threaded. The resultant fabric had 60 coarses per inch. The fabric was jet dyed according to a standard disperse dye cycle at 280° F., held for 20 minutes with a 2° F. per minute temperature ramp up. The fabric was wet pad tenter dried at a temperature of 300° F. passing through the tenter at 20 yards per minute. The exit width after drying was 59.5 inches. The resultant fabric had random high loops with relatively greater oriented crystalline regions than the low loops which were characterized by very low order orientation of the crystals as measured by wide angle X-ray scattering.
EXAMPLE 2A 115 denier 36 filament semi-dull round partially oriented polyester yarn was subjected to a 1.143 draw across a contact Dowtherm heater plate operated at a temperature of 175 C. The heater contact length was 17 inches and the yarn was taken up off of the heater at a rate of 600 yards per minute. The yarns were spaced at a density of approximately 17.4 yarns per inch across the heater. The warper tension was set at 25 to 32 grams. Overall draw ratio was 1.165. Measurements of the post drawn yarn indicated a linear density of 100.0 denier and a boiling water shrinkage of 12.04%. The drawn yarn was knitted into the face of a 4 bar 56 gauge Raschel knit fabric. The bar 1 yarn (tie down stitch) bar 2 yarn (tie down stitch) and bar 4 (ground yarn) were all formed of 70 denier 36 filament semi-dull round fully warpdrawn polyester. The face yarn was threaded in Bar 3. The bar 1 runner length was 60 inches. The bar 2 runner length was 60 inches. The bar 3 (face yarn) runner length was 102 inches. The bar 4 ground yarn runner length was 54 inches. The resultant fabric had 49.5 coarses per inch. The fabric was jet dyed at 280° F., held for 20 minutes with a 20 F per minute temperature ramp up. The fabrics were wet pad tenter dried at a temperature of 300° F. passing through the tenter at 20 yards per minute. The exit width after drying was 53 inches. The resultant fabric had random high loops with relatively greater oriented crystalline regions than the low loops which were characterized by very low order orientation of the crystals as measured by wide angle X-ray scattering. The tiedown stitching pronounced the height of the tall loops.
Loop Pile Fabric
In
Illustrated in
As in the individual yarn samples evaluated, due to the differentiated shrinkage of the filaments at different yarn segments in the fabric, the filaments within the low profile loop segments 526 of the pile portion 520 are characterized by a substantially greater diameter than the filaments in the high profile loops 525. By way of example only, for purposes of comparison refer to the photomicrographs of filament cross sections in exemplary low shrink yarn portions illustrated in
By way of example only, within a yarn 100′ according to the present invention it is contemplated that the number of interlace nodes will preferably be in the range of about 8 to 40 nodes per meter with each node taking up about 0.6 to about 1.3 cm. Thus, it is contemplated that zones of high retained shrinkage potential will preferably make up about 4.8% to about 52% percent of the total length of the yarn and will more preferably make up about 25% of the total length of the yarn.
As previously indicated, a substantial benefit of the present invention is that the low profile loop segments 526 of heat shrunk yarn are present across the surface of the fabric in a substantially random arrangement. This imparts a substantially natural random look which may be desirable in many instances. Moreover, since the low profile zones undergo heat shrinkage as a result of activating intrinsic heat shrink potential, such shrinkage occurs without embrittlement and results in a self crimping of the yarns in the low profile zones which emulates texturing thereby enhancing a soft feel and avoiding filament breakage leading to undesirable shredding. As previously indicated, after self-texturing takes place, the high shrink portions of the yarn have a lower level of crystalline orientation than the low shrink portions. In this regard it is contemplated that the level of crystalline orientation of the low shrink portions of the yarn as measured by the Herman Orientation Function will on average be at least 5% greater (and more preferably at least 10% greater) than the level of crystalline orientation of the high shrink portions.
The invention may be further understood through reference to the following non-limiting example: EXAMPLE 3
A 115 denier 36 filament semi-dull round partially oriented polyester yarn was subjected to a 1.143 draw across a contact Dowtherm heater plate operated at a temperature of 170 C. The heater contact length was 17 inches and the yarn was taken up off of the heater at a rate of 600 yards per minute. The yarns were spaced at a density of approximately 17.4 yarns per inch across the heater. The warper tension was set at 26 to 30 grams. Overall draw ratio was 1.165. Measurements of the post drawn yarn indicated a linear density of 103.6 denier, a boiling water shrinkage of 11.16%, an elongation of 87.46% and a breaking strength of 267 grams. The drawn yarn was knitted into the face of a 2 bar 56 gauge POL knit fabric with the ground being formed of a single ply 150 denier 36 filament semi-dull round false twist textured polyester. The bar 1 (face yarn) runner length was 135 inches. The bar 2 (ground yarn) runner length was 52 inches. The knitting machine was fully threaded. The resultant fabric had 66 coarses per inch with a pile height of 0.065 inches and a width of 57.25 inches. Samples of the resultant greige fabric were thereafter subjected to heat setting at 330° F. and at 410° F. No difference in the finished fabrics was observed. The fabric heat treated at 410° F. The fabrics were jet dyed at 266° F., held for 30 minutes with a 2° F. per minute temperature ramp up. The fabrics were wet pad tenter dried at a temperature of 250° F. passing through the tenter at 25 yards per minute. The exit width after drying was 56 inches. The resultant fabric had random high loops with relatively greater oriented crystalline regions than the low loops which were characterized by very low order orientation of the crystals as measured by wide angle X-ray scattering.
Cut Pile Fabric
In
Illustrated in
As in the individual yarn samples evaluated, due to the differentiated shrinkage of the filaments at different yarn segments in the fabric, the filaments within the low profile pile yarn segments 726 of the pile portion 720 are characterized by a substantially greater diameter than the filaments in the high profile pile yarns 725. By way of example only, for purposes of comparison refer to the photomicrographs of filament cross sections in exemplary low shrink yarn portions illustrated in
By way of example only, within a yarn 100′ according to the present invention it is contemplated that the number of interlace nodes will preferably be in the range of about 8 to 40 nodes per meter with each node taking up about 0.6 to about 1.3 cm. Thus, it is contemplated that zones of high retained shrinkage potential will preferably make up about 4.8% to about 52% percent of the total length of the yarn and will more preferably make up about 25% of the total length of the yarn.
As previously indicated, a substantial benefit of the present invention is that the low profile pile yarn segments 726 of heat shrunk yarn are present across the surface of the fabric in a substantially random arrangement. This imparts a substantially natural random look which may be desirable in many instances. Moreover, since the low profile zones undergo heat shrinkage as a result of activating intrinsic heat shrink potential, such shrinkage occurs without embrittlement and results in a self crimping of the yarns in the low profile zones which emulates texturing thereby enhancing a soft feel and avoiding filament breakage leading to undesirable shredding. As previously indicated, after self-texturing takes place, the high shrink portions of the yarn have a lower level of crystalline orientation than the low shrink portions. In this regard it is contemplated that the level of crystalline orientation of the low shrink portions of the yarn as measured by the Herman Orientation Function will on average be at least 5% greater (and more preferably at least 10% greater) than the level of crystalline orientation of the high shrink portions.
The invention may be further understood through reference to the following non-limiting example:
EXAMPLE 4A 175 denier 48 filament full dull round partially oriented polyester yarn was subjected to a 1.143 draw across a contact Dowtherm heater plate operated at a temperature of 215° C. The heater contact length was 17 inches and the yarn was taken up off of the heater at a rate of 600 yards per minute. The yarns were spaced 17.4 yarns per inch across the heater. The warper tension was 48 grams. Overall draw ratio was 1.165. Measurements of the post drawn yarn indicated a linear density of 151.8 denier and a boiling water shrinkage of 12.66%. The drawn yarn was knitted in the face of a 6-bar 32 gauge Double Needle Bar Knit machine with the ground being formed of a 150 denier 36 filament semi-dull round warp drawn polyester and a 212 denier 36 filament semi-dull round underdrawn polyester. The bar {fraction (3/4)} (pile yarns) runner length was 375 inches. The bar 2/5 (ground yarns) runner length was 90 inches and the bar 1/6 (ground yarn) runner length was 130 inches. The knit machine was fully threaded. The resultant sandwich fabric had a thickness of 0.205 inches and was subsequently slit to yield a pile height of {fraction (6/64)} inches. Samples of the resultant greige fabric were thereafter subjected to heat setting at 330° F. and at 410° F. No difference in the finished fabric was observed. The fabrics were jet dyed at 266° F., held for 30 minutes with a 2° F. per minute rate of rise. The fabrics were wet pad tenter dried at a temperature of 250° F. passing through the tenter at 25 yarns per minute. The exit width was 56 inches. The resultant fabric was characterized with a “pebbly” surface appearance.
Claims
1. A cut yarn pile fabric comprising a base portion and a pile portion, wherein the pile portion comprises a first group of cut yarn piles projecting outwardly from the base portion to a first height and at least a second group of cut yarn piles projecting outwardly from the base portion to a second height lower than the first height, wherein at least a portion of the first group of cut yarn piles and at least a portion of the second group of cut yarn piles are formed from segments of a common yarn and wherein in the fabric the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of yarn filaments characterized by an average cross-sectional area at least 1.56 times the average cross-sectional area of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.
2. The invention as recited in claim 1, wherein the cut yarn pile fabric is a knit fabric.
3. The invention as recited in claim 2, wherein the loop pile fabric is a double needlebar knit fabric.
4. The invention as recited in claim 2, wherein the loop pile fabric is a clip knit fabric.
5. The invention as recited in claim 2, wherein the loop pile fabric is a POL knit fabric.
6. The invention as recited in claim 1, wherein the common yarn is a multi-filament thermoplastic yarn.
7. The invention as recited in claim 6, wherein the material of the common yarn is selected from the group consisting of polyester, polypropylene, and nylon.
8. The invention as recited in claim 1, wherein the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of yarn filaments having a lower degree of crystalline orientation than the yarn filaments in the segments of the common yarn forming the first group of cut yarn piles such that the average level of crystalline orientation of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles as measured by the Herman Orientation Function is at least 5% greater than the average level of crystalline orientation of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles.
9. The invention as recited in claim 1, wherein the segments of the common yarn forming the second group of cut yarn piles are characterized by a substantially non-parallel arrangement of crimped yarn filaments.
10. The invention as recited in claim 1, wherein the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of substantially circular cross-section yarn filaments characterized by an average cross sectional diameter which is at least 50 percent greater than the average cross sectional diameter of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.
11. The invention as recited in claim 10, wherein at least a portion of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles are characterized by a cross sectional diameter which is at least twice the cross sectional diameter of one or more yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.
12. A cut yarn pile fabric comprising a base portion and a pile portion, wherein the pile portion comprises a first group of cut yarn piles projecting outwardly from the base portion to a first height and at least a second group of cut yarn piles projecting outwardly from the base portion to a second height lower than the first height, wherein at least a portion of the first group of cut yarn piles and at least a portion of the second group of cut yarn piles are formed from segments of a common yarn and wherein in the fabric the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of yarn filaments characterized by an average cross-sectional area which is at least 1.56 times the average cross sectional diameter of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles and wherein the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles are characterized by a lower degree of crystalline orientation than the yarn filaments in the segments of the common yarn forming the first group of cut yarn piles such that the average level of crystalline orientation of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles as measured by the Herman Orientation Function is at least 5% greater than the average level of crystalline orientation of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles.
13. The invention as recited in claim 12, wherein the common yarn is a multi-filament polyester yarn.
14. The invention as recited in claim 13, wherein the average level of crystalline orientation of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles as measured by the Herman Orientation Function is at least 10% greater than the average level of crystalline orientation of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles.
15. The invention as recited in claim 12, wherein the segments of the common yarn forming the second group of cut yarn piles are characterized by a substantially non-parallel arrangement of crimped yarn filaments.
16. The invention as recited in claim 15, wherein at least a portion of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles are substantially circular cross-sectional filaments characterized by a cross sectional diameter which is at least twice the cross sectional diameter of one or more yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.
17. A method of forming a cut yarn pile fabric comprising a base portion and a pile portion, wherein the pile portion comprises a first group of cut yarn piles projecting outwardly from the base portion to a first height and at least a second group of cut yarn piles projecting outwardly from the base portion to a second height lower than the first height, the method comprising the steps of:
- underdrawing a partially oriented multi-filament yarn across a heat source at a rate such that portions of the yarn undergo substantially complete heat setting and other portions do not undergo substantially complete heat setting;
- forming the yarn into the cut pile portion of the cut yarn pile fabric; and
- heating the fabric such that portions of the yarn which did not undergo substantially complete heat setting during the underdrawing step shrink towards the base portion of the fabric in a crimped self texturing manner.
Type: Application
Filed: Jul 2, 2004
Publication Date: Feb 3, 2005
Inventor: Michael Keller (Simpsonville, SC)
Application Number: 10/883,932