SELF-COATING COMPOSITE STABILIZING YARN

Abstract: A self-coating yarn having a low melt constituent (10) and a high melt constituent or effect yarn (20).

Description: SELF-COATING COMPOSITE STABILIZING YARN Field of the Invention The present invention relates to yarns used for outdoor fabrics. More particularly, the invention relates to a compounded or composite self-coating yarn which, when combined with other effect yarns, are capable of stabilizing and strengthening such fabrics without the use of a latex back coating or other topical treatments. Background of the Invention Compounded or composite yarns formed of high melt and low melt fibers or filaments are generally known for various applications. Examples of such yarns are described in United States Patents Nos. 5,651,168; 5,397,622; and 5,536,551. None of the above yarns, however, are appropriate for or intended for use as a stabilizing yarn for outdoor applications requiring a high degree of dimensional stability, and strength. The term "outdoor fabrics" as used herein is defined as fabric for awnings, tents, sling fabric for furniture, cushions, umbrellas, marine applications, convertible tops, and the like. The term "effect yarn" is intended to mean yarns, such as acrylics, polyester, and polypropylene, which are used in the construction of aesthetically appealing, softer blend decorative fabrics. Many yarns are inappropriate for outdoor use unless they are solution dyed and UV stable. Such yarns include acrylics, polyester, nylon, and polypropylene. The aforementioned yarns are not considered to be particularly dimensionally stable nor resistant to abrasion in open weave structures to the extent that, in use, they are either provided with a latex backing to improve stability or they have been used with the recognized deficiencies. Thus, there is a need for a stabilizing yarn suitable for use with effect yarns in the fabrication of open weave fabrics to be utilized in outdoor applications wherein such fabrics will be imparted with improved abrasion resistance, weave stability, strength and the other characteristics described hereinabove. Use of a latex backing is a recognized impediment to the use and acceptance of fabrics in outdoor applications. The application of a latex backing is expensive, requiring specialized machinery, additional chemical cost and, at times, slower tenter speeds or multiple passes through the tentering operation. It also provides a greater opportunity for mildew problems and renders a stiffer fabric with only one side available for decorative patterning. Summary of the Invention The present invention, therefore, is directed to a novel composite or compounded stabilizing yam intended for use with effect yams to fabricate an open weave fabric structure, or, when used in more tightly woven fabrics result in a fabric appearing and feeling to be heavier than it actually is. Outdoor fabrics which include as a component the yams of the present invention achieve strength and dimensional stability without being heavy and/or tightly woven. By use of the novel stabilizing yam of the present invention, a better hand is imparted and the resulting fabrics are made to "feel" heavier than they actually are. The stabilizing yam includes a coating constituent which provides the resulting fabric with superior weave stability, abrasion resistance and esthetic characteristics or properties without the need for latex back coatings. Wicking capability is another important characteristic for quick drying after exposure to water or other liquids. The yam of the present invention, therefore, is a self-coating composite stabilizing yam having low melt constituent and high melt constituent. The low and high melt constituents are intermingled in one of several yarn forming operations to provide a composite or compounded yam having a denier in the range of 400 to 4,000 or equivalent yam count. By "low melt" the present invention envisions a constituent having a melt temperature in the range of 240° F and 280° F. On the other hand, the "high melt" constituent is intended to be defined by a fiber or filament having a melt temperature of 280° F - 340° F or even greater. Stated otherwise the high melt constituent should have a melt temperature of at least 40-60° F above that of the low melt constituent. The composite or compounded ya may be formed in various ways. In one way a continuous filament low melt core yam can be combined with one or more ends of a continuous filament high melt outer effect ya with the filament ends being combined during a texturing operation, such as air jet texturing, false twist texturing, twisting, prior twisting, conventional covering and the like. In a second approach, low melt and high melt staple fibers may be homogeneously mixed or blended, then processed according to standard staple yam processing techniques. The resulting yam becomes self-coating and self-bonding in that the low melt constituent or component melts during a subsequent heat operation after fabric formation. Melted polymer then flows through the adjacent fibers or filaments and onto the adjacent effect yams to bind the individual fabric components together. This makes for a stronger yam. Further, the individual fabric yams are fixed in place and thereby the fabric structure is stabilized. The melting of the low melt constituent minimizes raveling, and seam slippage, imparts greater load elongation recovery, and greater abrasion resistance, and all without the application of a conventional latex backing. Since the latex backing can be eliminated, the resulting fabric is more esthetically acceptable with the color pattern of the yams being visible on both sides of the fabric. Further, in printing applications, the fabric may be printed on both sides. In a continuous lay down operation for pattern cutting, the fabric is folded exposing alternate sides in the finished product, and therefore the latex backing will not permit this technique. These and other aspects of the present invention will become apparent to those skilled in the art after reading of the following description of the preferred embodiments when considered in conjunction with the drawings. It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrative two embodiments of the invention and, together with the description, serve to explain the principles of the invention. Brief Description of the Drawings The above and other objects, features, and advantages of the present invention will become more apparent and will be more readily appreciated from the following detailed description of the preferred embodiments of the invention taken in conjunction with the accompanying drawings, in which: Figure 1. Is a representation of the processing of a composite ya in which a continuous filament core is delivered with one or more continuous effect filaments and subjected to an air texturing operation; and Figure 2. Is an illustration in which low melt and high melt fibers are blended, then processed according to standard processing to form a blended yam. Description of the Preferred Embodiments The self-coating composite yam of the present invention may be formed in accordance with Figure 1 or Figure 2. In general, such composite yams include both low melt and high melt constituents. The term "low melt" constituent is intended to mean fibers or filaments having a melt temperature below the temperature of the eventual tentering operation and generally in the range of 240-280° F. The term "high melt" constituent is intended to mean fibers or filaments having a melt temperature at least 40° F - 60° F higher than the melt temperature of the low melt constituent with which it is intended to be used. Thus, if the ensuing tentering operation is about 290° F, melt temperature of the low melt constituent may be selected at 260° F, and the high melt constituent should be selected to have a melt temperature of about 310°. Further, the high melt effect yam is preferably either acrylic, polyester, polypropylene, or nylon while the low melt yam is preferably polyethylene or polypropylene. The composite ya with which the present invention is intended includes deniers in the range of 400-4,000 or equivalent yam counts. By incorporating the self-coating aspect accomplished by use of the low melt constituent, composite yam itself and the resulting fabric realizes minimal or zero raveling. Examples of uses of various denier, by way of example include: • 400d- open weave, light weight fabrics, i.e. for cushions and shade fabrics • 1200d - heavier fabrics such as sling fabric • 2400d - even heavier fabrics such as for industrial uses or heavier slings • 3700d - heaviest fabrics also for industrial uses Further, the resulting yam is extremely abrasion resistant and will meet standards of up to 9,000 double rubs. Such yams create a fabric that is extremely resistant to slippage. By slippage resistant, it is meant that fabrics formed from such yams when subjected to an Instron slippage test exhibit an increase in seam slippage from about 20 lbs. in the case of conventionally known fabrics to 40 lbs., and in some instances, even greater than 60 lbs. Also such fabrics formed with the yams of the present invention will have an increase in load recovery from about 80%, as in the case of conventional fabrics to 95% and better in the case of fabrics formed with the yams of the present invention. One way of producing a yam in accordance with a first embodiment of the invention is illustrated in Figure 1. One end 10 of a continuous filament low melt yam, such as polyethylene passes between draw rollers 12, 14 and is introduced into an air texturing zone 30. The low melt, continuous filament end 10 becomes the core yam of a composite yam 40 which is ultimately delivered to a take up package 50. Core yam 10 is drawn between rollers 12 and 14 at a 3 to 1 ratio. The core yam 10 is, by way of example, selected with a denier of 750, and therefore enters the air texturing zone as a filament having a denier of 250. Two effect yams, 20, 21 are drawn from separate packages. Effect yam 20 is passed between draw rollers 22, 24, while effect yam is drawn between rollers 23, 25. The effect yams are drawn at a 1.65 to 1 ratio from an initial denier in the range of 250-5,700 from 150 denier to 3,500 denier. Resulting compound or composite yam ranges from a denier of 400 to 4,000. The core ya is selected from the group consisting of polyethylene, polypropylene and other olefins, whereas the effect yarn is selected from the group consisting of acrylic, polyester, polypropylene and nylon. Other texturing techniques may be utilized though an air texturing process is described hereinabove. Turning now to a second embodiment, as illustrated in Figure 2 bales 1 10, 1 12, 114, and 116. The bales deliver staple fiber into weigh hoppers 120, 122, 124, and 126 and weigh pans 121, 123, 125, and 127 therebelow. The weigh pans 121, 123, 125, and 127 deliver measured amounts of staple fiber onto a conveyer belt 130 in layers 140, 142, 144, and 146. Finally, the layers are delivered to a card 150 at the end of the conveyer belt where the fibers are homogeneously mixed and aligned during the carding operation. The subsequent conventional processing by drawing, roving, ring spinning, winding, and twisting produce the final compounded ya . In order to produce a typical blend of 90% acrylic/10% polyethylene, staple fibers are removed from bales 110, 112, 114, and 116. Each bale will contain one type of fiber. For example, bale 110 would include acrylic, bale 112 polyethylene, bale 114 acrylic, and bale 116 polyethylene. By use of way pans 121, 123, 125 and 127, measured amounts of acrylic and polyethylene would be deposited onto a conveyor. For example, way pans 121 and 123 would be initially set to deliver nine parts of acrylic for each one part of polyethylene. Depending upon the results actually achieved in the initial weighing, weigh pans 125 and 127 could be adjusted to provide a blended sandwich of 90% acrylic and 10% ethylene by weight. While one technique for producing staple yam has been illustrated, it is apparent that other techniques are available.

Claims: WHAT IS CLAIMED IS: 1. A self-coating composite yam for outdoor fabrics comprising: a) a polymeric high melt constituent having a melt temperature of at least 280% F; b) a polymeric low melt constituent having a melt temperature no greater than 280% F; c) the difference between said low melt constituent and said high melt constituent being at least 40° F; d) said high melt and low melt constituents being intermingled to form said composite yam; e) said composite yam having a denier of 400-4,000; f) whereby after said yarn is formed into said fabric and subjected to heat of at least 240° F, said yam becomes self-coating and self-bonding. 2. The self-coating composite yam according to claim 1 wherein the denier of said low melt constituent just prior to the intermingling step is about 250d and the high melt constituent is in the range of 150d - 3,500d. 3. The self-coating composite yam according to claim 1 wherein said low melt constituent is selected from the group consisting of polyethylene and polypropylene. 4. The self-coating composite ya according to claim 1 wherein said high melt constituent is selected from the group consisting of acrylic, polyester, polypropylene, and nylon. 5. The self-coating composite yam according to claim 1 having minimal or zero raveling. 6. The self-coating ya according to claim 1 wherein said self-coating yam comprises one end of continuous filament low melt core yam, at least one end of continuous filament high melt outer effect yam, said core and effect yams being air textured. 7. The self-coating composite yam according to claim 6 wherein said core yam is selected from the group consisting of polyethylene and polypropylene, and the effect yams are selected from acrylic, polyester, nylon, and polypropylene. 8. The self-coating composite yam according to claim 7 wherein said composite yam is substantially strong before heat setting to withstand drawing at a 3-1 ratio and texturing on high speed texturing equipment. 9. The self-coating composite yam according to claim 6 wherein said core yam is 750 denier drawn at a 3-1 ratio to 250 denier and each effect yam is initially 250 denier-5,700 denier drawn at a ratio of 1.65-1 to a denier in the range of 150-3,500. 10. The self-coating composite yam according to claim 9 wherein said composite yam has a composite denier in the range of 400-4,000d. 11. The self-coating composite yam according to claim 1 comprising a blend of low melt and high melt staple fibers homogeneously mixed and processed according to standard blended yam forming procedures. 12. The self-coating composite yam according to claim 1 1 wherein said low melt and high melt staple fibers comprise polyethylene low melt fibers and acrylic high melt fibers. 13. The self-coating composite yam according to claim 1 1 wherein the ratio of high melt fibers to low melt fibers is approximately 10-1. 14. The self-coating yam according to claim 11 wherein said homogeneously mixed staple fibers are sufficiently strong before heat setting to withstand high speed carding, spinning, winding and twisting. 15. The self-coating composite yam according to claim 11 wherein said final product has a denier in the range of 400-4,000d.

Inventors: PARRISH JOHNNY E, SWERS DAVID N, PARRISH, JOHNNY, E., SWERS, DAVID, N.
Applicants: RAVEN MILLS GLEN, GLEN RAVEN MILLS, INC.
Application year: 1999
Main classification: D01F8
IPC codes: D02G3