Patent Grant
7934397
1. Field of the Invention
This invention relates to improved constructions of cut-resistant knitted gloves containing glass filaments and para-aramid fiber. The gloves have improved comfort and abrasion resistance in part because of the addition of a mobile companion yarn in the knit structure.
2. Description of Related Art
Cut-resistant gloves are commercially available that are knit with para-aramid fiber yarns plated to such things as cotton, with the layer of cotton located on the inside of the glove next to the skin. The cotton helps improve the comfort of the glove because para-aramid fibers can be abrasive to the skin. U.S. Pat. No. 6,044,493 to Post discloses a protective material such as a glove comprising a plurality of cut-resistant strands and a plurality of elastic strands knitted together to form a plated knit in which the cut-resistant strands form the outer surface and the elastic strands form the inner surface of the material.
In an effort to improve the cut performance of cut-resistant yarns, materials with high hardness have been combined with cut-resistant yarns. U.S. Pat. No. 5,119,512 to Dunbar et al. discloses cut-resistant yarn, fabric and gloves made from a single yarn comprising at least one flexible cut-resistant fibrous material and at least another material having a high level of hardness. U.S. Pat. No. 6,161,400 to Hummel discloses cut-resistant fabric and gloves made from two different yarns, one that contains cut-resistant fiber and one that contains fibers having high hardness. One of the two yarns is located predominantly on the exterior of the glove and the other predominantly on the interior. Likewise, U.S. Pat. No. 5,965,223 to Andrews et al. discloses a protective fabric and glove that has, at a minimum, an outer layer made with a yarn composed of an abrasive material plated to an inner layer of inherently cut-resistant or high-tensile strength material.
Bare glass fiber, while having high hardness, is also very brittle, easily abraded, and is highly irritating to the skin. One solution to this skin irritation problem has been to use fiberglass in the form of what has generally been referred to as composite yarns or wrapped yarns; that is, filaments of glass fiber are covered by a plurality of helically wrapped yarns. Representative yarns and processes for making such yarns as disclosed, for example, in U.S. Pat. No. 5,628,172 to Kolmes et al. and U.S. Pat. No. 5,845,476 to Kolmes. These wrappings generally are closely spaced and/or tightly wrapped around the core fiberglass filaments so as to get good coverage, but the unintended result is these composite or wrapped yarns tend to be stiff.
Further, such wrapped yarns help prevent skin irritation as long as the composite yarns remained undamaged. Unfortunately, during normal use, such gloves get nicks and abrasions that uncover the fiberglass which can irritate the skin even though the gloves remain useable.
Therefore what is needed is an improved glove construction for improved comfort and abrasion resistance during normal use.
This invention relates to a cut-resistant knit glove comprising
a) cut-resistant composite yarn having a core comprising at least two core yarns and at least one first wrapping yarn helically wrapped around the core, the core yarns including at least one 50 to 600 denier (56 to 680 dtex) glass fiber filament yarn and at least one 100 to 600 denier (110 to 680 dtex) para-aramid yarn, the first wrapping yarn including at least one 100 to 600 denier (110 to 680 dtex) yarn selected from the group of consisting of para-aramid, aliphatic polyamide, polyester, and mixtures thereof;
b) companion yarn having a linear density of from 100 to 1800 denier (110 to 2000 dtex) comprising para-aramid; and
c) lining yarn comprising either
This invention relates to a cut-resistant knit glove construction comprising at least three types of yarns. These yarns include a cut-resistant composite yarn containing fiberglass, a companion yarn, and a liner yarn that are co-knit together with the lining yarn plated on the interior of the glove.
Cut-Resistant Composite Yarn
The cut-resistant composite yarn has a core comprising at least two different core yarns and at least one wrapping yarn helically wrapped around the two combined core yarns. At least one of the core yarns is glass fiber filament yarn having a linear density of from 50 to 600 denier (56 to 680 dtex). It is thought a denier less than 50 (dtex less than 56) does not provide adequate cut protection, while a denier greater than 600 (dtex greater than 680) results in a thicker fabric than is desired. In some preferred embodiments, the final glove size is 10 gauge or thicker, and in some embodiments the glass fiber filament yarn has a linear density of from 100 to 200 denier (110 to 220 dtex).
The terms glass fiber and fiberglass are used interchangeably herein to mean glass fiber filament yarn. Glass fiber is formed by extruding molten silica-based or other formulation glass into thin strands or filaments with diameters suitable for textile processing. Two types of fiberglass commonly used are referred to as S-glass and E-glass. E-glass has good insulation properties and will maintain its properties up to 1500 degrees F. (800 degrees C.). S-glass has a high tensile strength and is stiffer than E-glass. Suitable glass fiber is available from B&W Fiber Glass, Inc. and a number of other glass fiber manufacturers. In some embodiments, the use of E-glass is preferred in the cut-resistant composite yarn.
This core yarn is combined with at least one other core yarn that is a para-aramid yarn having a linear density of from 100 to 600 denier (110 to 680 dtex). Para-aramid fibers are made from an aramid polymer wherein the two rings or radicals are para oriented with respect to each other along the molecular chain. Methods for making para-aramid fibers are generally disclosed in, for example, U.S. Pat. Nos. 3,869,430; 3,869,429; and 3,767,756. Such aromatic polyamide organic fibers and various forms of these fibers are available from E. I. du Pont de Nemours & Company, Wilmington, Del. sold under the trademark Kevlar® fibers and from Teijin Ltd. of Japan sold under the trademark Twaron® fibers. For the purposes herein, Technora® fiber, which is available from Teijin Ltd. of Tokyo, Japan, and is made from copoly(p-phenylene/3,4′diphenyl ester terephthalamide), is considered a para-aramid fiber. In some embodiments, the para-aramid yarn comprises staple fibers, and in some embodiments the para-aramid yarn comprises continuous filaments. In some embodiments, the para-aramid is poly(paraphenylene terephthalamide).
At least one wrapping yarn including at least one 100 to 600 denier (110 to 680 dtex) yarn selected from the group of consisting of para-aramid, aliphatic polyamide, polyester, and mixtures thereof is then helically wrapped around the core yarns. In some embodiments, the para-aramid yarn is wrapped around the core yarn at a frequency of 5 to 20 turns per inch (2 to 8 turns per cm). A higher frequency than 20 turns per inch (8 turns per cm) will result it a very stiff yarn and a lower frequency than 5 turns per inch (2 turns per cm) will hurt the durability of the glove in that the glass fiber filament core will not be fully covered. In some embodiments, the wrapping yarn is a spun staple yarn, in some other embodiments the wrapping yarn is a continuous filament yarn. In some preferred embodiments, the wrapping yarn is a textured continuous filament yarn.
Since highly cut resistant yarns are used in the core and optionally the wrapping of the cut-resistant composite yarn, it is the inclusion of this composite yarn that provide the primary cut resistance to the glove. In some preferred embodiments the core of the cut-resistant composite yarn consists solely of only two core yarns, one of fiberglass and the other of para-aramid fiber, and the wrapping consists solely of para-aramid fiber, with poly(paraphenylene terephthalamide being the para-aramid used in the composite yarn.
Companion Yarn
While the cut-resistant composite yarn can include a plurality of wrapping yarns about the core yarns, only one yarn is preferred due to stiffness imparted to the cut-resistant composite yarn, caused by multiple tight helical wrappings of the yarn about the cores. Instead, additional protection from the potential irritation from the fiberglass of the cut-resistant composite yarn is provided by a companion yarn knit with the cut-resistant composite yarn that helps randomly cover the cut-resistant composite yarn.
The companion yarn is a 100 to 1800 denier (110 to 2000 dtex) yarn comprising para-aramid fiber. The companion yarn also provides lubricity to the yarn bundle knitted in the glove, allowing the knitted yarns more mobility in the knitted structure. In some embodiments the linear density of the companion yarn has a linear density of 500 denier (560 dtex) or greater. In some embodiments, the companion yarn is 1650 denier (1840 dtex) or less. In some preferred embodiments, the companion yarn consists solely of a single type fiber in the yarn, such as poly(paraphenylene terephthalamide) fiber. In some embodiments, the companion yarn can be singles yarns; in some embodiments the companion yarn can be double or plied yarns. In some embodiments the companion yarn is a spun staple yarn, in some other embodiments the companion yarn is a continuous filament yarn. In some preferred embodiments, the companion yarn is a textured continuous filament yarn.
Lining Yarn
The third yarn component in the knitted glove provides a layer of a looped lining yarn next to the skin. In one embodiment, the lining yarn comprises a composite yarn having a total yarn linear density of from 100 to 500 denier (110 to 560 dtex) and having an elastomeric yarn core comprising at least one elastomeric yarn and at least one wrapping yarn helically wrapped around the yarn core. The wrapping serves to protect the somewhat less durable elastomeric yarn from abrasion during knitting and in use in the glove. In some preferred embodiments, the composite yarn contains solely apparel staple fiber yarns, that is, yarns used in traditional wearing apparel, such as aliphatic polyamide fibers, polyester fibers, natural fibers, cellulosic fibers, and mixtures thereof. In some embodiments, the wrapping yarn consists solely of a single type of yarn. In some embodiments, the wrapping yarn can be singles yarns; in some embodiments the wrapping yarn can be double or plied yarns. In some embodiments, the wrapping yarn is a spun staple yarn, in some other embodiments the wrapping yarn is a textured continuous filament yarn.
In some embodiments, the elastomeric yarn has a linear density of from 20 to 100 denier (22 to 110 dtex). In some embodiments, the elastomeric yarn has a linear density of 75 denier (84 dtex) or less, and in some preferred embodiments it has a linear density of 30 to 50 denier (33 to 56 dtex). In some embodiments, the elastomeric yarn is a spandex yarn. While in some embodiments the preferred elastomeric fiber yarn is a spandex fiber yarn, any fiber generally having stretch and recovery can be used. As used herein, “spandex” has its usual definition, that is, a manufactured fiber in which the fiber-forming substance is a long chain synthetic polymer composed of at least 85% by weight of a segmented polyurethane. Among the segmented polyurethanes of the spandex type are those described in, for example, U.S. Pat. Nos. 2,929,801; 2,929,802; 2,929,803; 2,929,804; 2,953,839; 2,957,852; 2,962,470; 2,999,839; and 3,009,901.
The at least one yarn helically wrapped around the elastomeric yarn core has a linear density of from 20 to 300 denier (22 to 340 dtex) and is selected from the group consisting of aliphatic polyamide, polyester, natural fibers, cellulosic fibers, and mixtures thereof. In some embodiments, the yarn is wrapped around the elastomeric yarn core at a frequency of 5 to 20 turns per inch (2 to 8 turns per cm). A higher frequency than 20 turns per inch (8 turns per cm) will result in a stiffer yarn than desired and a lower frequency than 5 turns per inch (2 turns per cm) will not adequately cover the elastomeric yarn core.
In another embodiment, the lining yarn is a spun staple yarn, a continuous filament yarn, or a textured continuous filament yarn having a total yarn linear density of from 100 to 1200 denier (110 to 1300 dtex). In some preferred embodiments the lining yarn contains solely apparel staple fiber yarns, that is, yarns used in traditional wearing apparel, such as aliphatic polyamide fibers, polyester fibers, natural fibers, cellulosic fibers, and mixtures thereof. In some embodiments, the lining yarn consists solely of a single type of yarn. In some embodiments, the lining yarn can be singles yarns; in some embodiments the lining yarn can be double or plied yarns.
In some preferred embodiments the lining yarn provides high comfort with softness and moisture regain. In some preferred embodiments the lining yarn includes blends of cotton (or cellulosic fiber) and polyester or nylon, with the cotton or cellulosic fiber content being more than 50 percent weight of the lining yarn.
Glove
The glove is constructed such that the lining yarn is plated during knitting on the interior of the glove, while the cut resistant composite yarn and companion yarn are plated during knitting on the exterior of the glove. Construction of the glove in this manner provides several advantages. The wearer of the glove is thus provided with improved protection from the cut resistant composite yarn in two ways, first by the lining yarn that contacts the skin of the wearer and separates the cut resistant yarn from the skin, and second by the companion yarn, which is randomly positioned between the lining yarn and the cut resistant composite yarn throughout the glove.
For improved comfort, in preferred embodiments the companion yarn is not pre-assembled with the cut-resistant composite yarn prior to forming the exterior of the glove. This allows the companion yarn and the cut-resistant composite yarn to shift in relationship to each other on a localized scale. In the preferred embodiment, the companion yarn and the cu-resistant composite yarn are not restricted from moving against one another longitudinally within the layer along the surfaces of the yarn because they are not joined or twisted together in the fabric, but can move in relation to each other for improved comfort and abrasion resistance.
Further, the companion yarn and the cut-resistant composite yarn lie in the same knit layer in the glove but can move locally within that layer to shift either to the exterior or the interior of the layer; that is, the two yarns are knit such that the companion yarn is not preferentially located in the glove fabric either to the interior of the cut-resistant composite yarn in the glove or to the exterior of the cut-resistant composite yarn in the glove, but is randomly distributed over the exterior, the interior, and beside the cut-resistant composite yarn. This allows the companion yarn to provide both additional abrasion resistance to cut-resistant composite yarn from the outside of the glove while also providing additional cover from the cut-resistant composite yarn to the inside of the glove, adding additional protection to the wearer.
In some preferred embodiments, the entire glove, with the exception of any special treatment for the cuff, is knitted using the combination of cut-resistant composite yarn, companion yarn, and lining yarn. That is, as shown in the Figure, the entire surface of all finger stalls 2 of the glove 1, and the tubular portion 3 of the glove that forms the palm, sides, and back of the glove, are formed from a combination of yarns consisting of the cut-resistant composite yarn, companion yarn, and the lining yarn. Typically, the sleeve or cuff 4 of the glove can have additional elastomeric yarn to if desired; if the cuff is different, it still comprises the three yarn combination plus any additional gripping or sealing yarns or features.
In one embodiment, the gloves are very suitable when a heavier weight cut-resistant glove having improved protection from the irritation from fiberglass is desired. In some embodiments, the glove has a knit fabric basis weight for from 14 to 24 ounces per square yard (475 to 815 grams per square meter). In some embodiments, the gloves have a cut resistance index of 100 grams force per ounce per square yard of fabric (3 grams force per gram per square meter of fabric) or higher.
Process for Making Gloves
In one embodiment, a glove can be made by first assembling the individual yarns used in the glove and creating a first bobbin of cut-resistant composite yarn, a second bobbin of companion yarn, and a third bobbin of lining yarn. The yarns from the three individual bobbins are then co-knit directly, essentially in one step, into a glove using commercially available glove knitting machines, such as those made by Shima Seiki Corporation. These machines can knit completed gloves from the individual yarns. In a preferred embodiment, the individual yarns are fed to the knitting machine without plying or otherwise combining the yarns. The liner yarn is fed into the knitter and held in such a way that is in front of the cut-resistant and companion yarns when the yarns are knitted so that the liner yarn it plated throughout the inside surface of the glove. The resulting glove has a mixture of cut-resistant and companion yarns throughout the outside surface of the glove and the liner yarn throughout the inside surface of the glove.
Coated Gloves
If additional gripping performance is desired for the glove, a flexible polymer coating can be provided to the glove. In some embodiments, the glove is provided with an exterior synthetic polymer coating selected from the group consisting of nitrile, latex, polyurethane, neoprene, rubber, and mixtures thereof. Generally, such coatings are applied by dipping the glove or a portion of the glove into a polymer melt or solution and then curing the coating.
Cut Resistance. The method used is the “Standard Test Method for Measuring Cut Resistance of Materials Used in Protective Clothing”, ASTM Standard F 1790-97. In performance of the test, a cutting edge, under specified force, is drawn one time across a sample mounted on a mandrel. At several different forces, the distance drawn from initial contact to cut through is recorded and a graph is constructed of force as a function of distance to cut through. From the graph, the force is determined for cut through at a distance of 25 millimeters and is normalized to validate the consistency of the blade supply. The normalized force is reported as the cut resistance force. The cutting edge is a stainless steel knife blade having a sharp edge 70 millimeters long. The blade supply is calibrated by using a load of 400 g on a neoprene calibration material at the beginning and end of the test. A new cutting edge is used for each cut test. The sample is a rectangular piece of fabric cut 50×100 millimeters on the bias at 45 degrees from both the warp and fill. The mandrel is a rounded electroconductive bar with a radius of 38 millimeters and the sample is mounted thereto using double-face tape. The cutting edge is drawn across the fabric on the mandrel at a right angle with the longitudinal axis of the mandrel. Cut through is recorded when the cutting edge makes electrical contact with the mandrel. As reported herein, the index is preferably reported as the cut through force in grams divided by the basis weight in ounces per square yard, but conversion to SI units is easily accomplished.
Abrasion Performance. The abrasion performance of fabrics is determined in accordance with ASTM D-3884-01 “Standard Guide for Abrasion Resistance of Textile Fabrics (Rotary Platform, Double Head Method)”. The number of cycles to abrade the knit fabric to the first hole is recorded as the abrasion resistance of the glove fabric.
Cut-resistant composite yarns were made as follows and collected on individual bobbins. Cut-resistant Composite Yarn 1A was made with a core of 200 dtex (200 denier) glass fiber yarn combined with a 590 dtex (532 denier or 20/2 cotton count) poly(paraphenylene terephthalamide) staple fiber spun yarn. These combined core yarns were wrapped by a single helically wrapping yarn of 480 dtex (440 denier) poly(paraphenylene terephthalamide) continuous filament textured yarn.
Cut-resistant Composite Yarn 1B was identical to 1A except the wrapping yarn was replaced with 560 dtex (500 denier) aliphatic polyamide (nylon) continuous filament textured yarn.
Cut-resistant Composite Yarn 1C with a core of 200 dtex (200 denier) glass fiber yarn wrapped by a single helically wrapping yarn of a 295 dtex (266 denier or 20/1 cotton count) poly(paraphenylene terephthalamide) staple fiber spun yarn.
Cut-resistant Composite Yarn 1D was made with a core of 200 dtex (200 denier) glass fiber yarn combined with a 560 dtex (500 denier) aliphatic polyamide (nylon) continuous filament textured yarn. These combined core yarns were wrapped by a single helically wrapping yarn of 560 dtex (500 denier) aliphatic polyamide (nylon) continuous filament textured yarn.
Cut-resistant Composite Yarn 1E was made with a core consisting of three core yarns that included a 200 dtex (200 denier) glass fiber yarn, a 590 dtex (532 denier or 20/2 cotton count) poly(paraphenylene terephthalamide) staple fiber spun yarn and a 680 dtex (600 denier) poly(paraphenylene terephthalamide) continuous filament yarn These combined core yarns were wrapped by a single helically wrapping yarn of 560 dtex (500 denier) aliphatic polyamide (nylon) continuous filament textured yarn.
Cut-resistant Composite Yarn 1F was the same as Yarn 1E except the wrapping yarn was replaced with two 167 dtex (150 denier) polyester continuous filament textured yarns.
Cut-resistant Composite Yarn 1G was identical to 1A except the wrapping yarn was replaced with two 167 dtex (150 denier) polyester continuous filament textured yarns.
Seventeen different gloves were then knit using yarns from individual bobbins of cut-resistant composite yarn, companion yarn, and liner yarn by feeding the individual yarns without any prior assembly (i.e. plying, twisting) of the yarns into a Shima Seiki automatic glove knitting machine having plating capability. Gloves of 7- and 10-guage construction (the heavier gloves being 7 guage) were made with the lining yarn plated on the interior of the gloves and the cut-resistant composite yarn and the companion yarn on the exterior of the glove. Glove properties are shown in the Table. In the table, PPD-T represents poly(paraphenylene terephthalamide).
All the gloves had good cut resistance indexes. All of the gloves having all three yarn components, the cut-resistant composite yarn, the companion yarn, and liner yarn; with the lining yarn plated on the interior of the gloves and the cut-resistant composite yarn and the companion yarn on the exterior of the glove, had excellent subjective feel and comfort when worn. Glove designs 10 and 11, composed of only cut-resistant composite yarns, had overall a lower combination of cut, abrasion, and comfort properties and were very stiff. Glove designs 14 and 15, composed of only cut-resistant composite yarns and liner yarns plated on the inside of the gloves, had a better combination of good cut and abrasion properties but had reduced comfort despite having the liner yarn plated on the inside. All of the remaining gloves had a good balance of good cut resistance, abrasion resistance, and comfort, and showed that the balance of properties could be adjusted to provide more or less cut resistance or abrasion resistance, all with excellent comfort. Also although glove design 4 had two ends of the cut-resistant composite yarn, each containing 220 dtex glass fiber, the cut resistance was similar to the number of other gloves containing only one end 200D glass fiber. Therefore using this construction, a minimum glass content of one yarn can be used to achieve excellent cut resistance, abrasion resistance, and comfort.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2929801 | Koller | Mar 1960 | A |
| 2929802 | Katz | Mar 1960 | A |
| 2929803 | Frazer et al. | Mar 1960 | A |
| 2929804 | Steuber | Mar 1960 | A |
| 2953839 | Kohrn et al. | Sep 1960 | A |
| 2957852 | Frankenburg et al. | Oct 1960 | A |
| 2962470 | Jung | Nov 1960 | A |
| 2999839 | Arvidson, Jr. et al. | Sep 1961 | A |
| 3009901 | Frazer | Nov 1961 | A |
| 3490224 | Bourgeas | Jan 1970 | A |
| 3767756 | Blades | Jun 1972 | A |
| 3869429 | Blades | Mar 1975 | A |
| 3869430 | Blades | Mar 1975 | A |
| 4384449 | Byrnes et al. | May 1983 | A |
| 4470251 | Bettcher | Sep 1984 | A |
| 4838017 | Kolmes et al. | Jun 1989 | A |
| 4936085 | Kolmes et al. | Jun 1990 | A |
| 5119512 | Dunbar et al. | Jun 1992 | A |
| 5177948 | Kolmes et al. | Jan 1993 | A |
| 5628172 | Kolmes et al. | May 1997 | A |
| 5845476 | Kolmes | Dec 1998 | A |
| 5965223 | Andrews et al. | Oct 1999 | A |
| 6016648 | Bettcher et al. | Jan 2000 | A |
| 6044493 | Post | Apr 2000 | A |
| 6155084 | Andrews et al. | Dec 2000 | A |
| 6161400 | Hummel | Dec 2000 | A |
| 6260344 | Chakravarti | Jul 2001 | B1 |
| 6266951 | Chakravarti | Jul 2001 | B1 |
| 6279305 | Hummel | Aug 2001 | B1 |
| 6341483 | Kolmes et al. | Jan 2002 | B1 |
| 6349531 | Kolmes et al. | Feb 2002 | B1 |
| 6351932 | Hummel | Mar 2002 | B1 |
| 6363703 | Kolmes | Apr 2002 | B1 |
| 6381940 | Kolmes et al. | May 2002 | B1 |
| 6413636 | Andrews et al. | Jul 2002 | B1 |
| 6460192 | Kindler | Oct 2002 | B2 |
| 6467251 | Kolmes | Oct 2002 | B1 |
| RE38136 | Kolmes | Jun 2003 | E |
| 6581366 | Andrews | Jun 2003 | B1 |
| 6701703 | Patrick | Mar 2004 | B2 |
| 6779330 | Andrews et al. | Aug 2004 | B1 |
| 6826898 | Hummel | Dec 2004 | B1 |
| 6978643 | Akers et al. | Dec 2005 | B2 |
| 7111445 | Threlkeld et al. | Sep 2006 | B2 |
| 7121077 | Andrews et al. | Oct 2006 | B2 |
| 7178323 | Kolmes et al. | Feb 2007 | B2 |
| 7332196 | Kosuge et al. | Feb 2008 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20100186457 A1 | Jul 2010 | US |
