US 20090007313 A1
An improved protective knitted glove assembly includes a knitted glove and two or more non-coplanar arrays of printed guard plates. The guard plates are small, regularly-spaced, generally uniform thickness, non-overlapping, hard polymer material members arranged in a predetermined pattern having an area parallel to a surface of the glove with major and minor dimensions. The major dimension to minor dimension aspect ratio of the guard plates is between about 3 and 1. The overall abrasion resistance of the glove assembly is substantially greater than an abrasion resistance of the knitted glove without the guard plates.
1. A protective knitted glove assembly; comprising:
a knitted glove; and
two or more non-coplanar arrays of small, regularly-spaced, generally uniform thickness, non-overlapping, hard printed polymer material guard plates arranged in a predetermined pattern and having an area parallel to a surface of the glove with major and minor dimensions, wherein the major dimension to minor dimension aspect ratio is between about 3 and 1 and the overall abrasion resistance of the glove assembly is substantially greater than an abrasion resistance of the knitted glove without the guard plates.
2. The protective knitted glove assembly of
a first array of guard plates on at least portions of a palm side of the glove; and
a second array of guard plates on at least portions of sides of one or more fingers of the glove.
3. The protective knitted glove assembly of
4. The protective knitted glove assembly of
5. The protective knitted glove assembly of
6. The protective knitted glove assembly of
7. The protective knitted glove assembly of
8. The protective knitted glove assembly of
9. The protective knitted glove assembly of
10. The protective knitted glove assembly of
11. The protective knitted glove assembly of
12. The protective knitted glove assembly of
12. A method for making a protective knitted glove assembly, including:
placing a first portion of a knitted glove on a generally planar surface of a former;
screen printing onto the first portion of the knitted glove a first array of small, regularly-spaced, generally uniform thickness, non-overlapping, polymer material guard plates arranged in a predetermined pattern;
placing a second portion of the knitted glove that is non-coplanar with the first portion on a generally planar surface of a former;
screen printing onto the second portion of the knitted glove a second array of small, regularly-spaced, generally uniform thickness, non-overlapping, polymer material guard plates arranged in a predetermined pattern, wherein the second array of guard plates is non-coplanar with the first array of guard plates; and
curing the polymer material to harden the guard plates.
13. The method of
placing a first portion of a knitted glove on a former includes placing at least a portion of a palm side of the glove on a former;
screen printing onto a first portion of the knitted glove includes screen printing the first array of guard plates onto at least a portion of a palm side of the knitted glove on the former;
placing a second portion of the knitted glove on a former includes placing at least a portion of a side of one or more fingers on a former; and
screen printing onto a second portion of the knitted glove includes screen printing the second array of guard plates onto at least a portion of a side of a finger of the glove on the former.
14. The method of
placing at least a portion of a side of one or more fingers on a former includes placing a former between the thumb and forefinger with at least a portion of the sides of the thumb and forefinger on a planar surface of the former; and
screen printing the second array of guard plates includes screen printing guard plates onto at least a portion of the sides of the thumb and forefinger.
15. The method of
16. The method of
placing at least a portion of a back of the glove on a former; and
screen printing an array of small, regularly-spaced, generally uniform thickness, non-overlapping, polymer material guard plates arranged in a predetermined pattern on at least a portion of the back of the glove.
17. The method of
partially curing the polymer material of the first array of guard plates before screen printing the second array of guard plates; and
fully curing the polymer material of the first and second arrays after screen printing the second array of guard plates.
18. The method of
19. The method of
This application claims the benefit of U.S. Provisional Application Ser. No. 60/942,377 filed on Jun. 6, 2007, and entitled “Abrasion And Slash Resistant Knitted Gloves,” which is incorporated herein by reference in its entirety.
The invention relates generally to knitted gloves.
Conventional fabrics are often easily frayed or damaged when they abrade against the rough surfaces of hard objects such as coarse cement, rocks, and asphalt. Yarns and fibers, especially on the surface of fabrics tend to abrade, lose mass, or even melt due to the heat of friction when exposed to relatively high abrasion conditions.
High-performance fabrics have been developed for some abrasion applications. One approach is to tightly weave or knit high denier yarn (e.g. nylon, polyester, etc.) into a fabric. Thermoplastic coatings can be applied to such fabrics to enhance abrasion resistance. Various high strength fibers (e.g. Kevlar®, PBO, steel, glass, Dyneema®) are sometimes used in high performance fabrics. However, these high strength fibers tend to be brittle, and therefore, are not associated with exceptional abrasion performance in many applications.
Further, many current high performance or abrasion resistant fabrics are bulky, stiff and expensive. Moreover, many abrading objects have sharp or pointed features (e.g. tree branches or rocks) that can snag the fabric and cause failure from tearing or puncturing.
HDM manufactures and sells sheets of SuperFabric® brand material that provide slash and abrasion resistance through the use of hard plates screen printed onto and affixed to the surface of a fabric in a closely spaced geometric pattern. This material is made into gloves by die cutting parts from the sheets and sewing or bonding the parts onto a glove. This results in a glove with excellent cut and abrasion resistance. However, this glove manufacturing method can be inefficient.
Gloves are often made from a knitting process. Rubber dots are sometimes printed onto knitted gloves to improve their grip properties. However, the material used in these dots is purposely chosen to be a relatively soft material since this gives the best grip enhancement for many applications. These soft rubber dots, however, provide little if any puncture or cut resistance. Moreover, when soft rubber dots are used, the abrasion resistance is not improved enough for practical applications where hard abrading objects can cut into and damage the material of the rubber dot.
The invention is an improved protective knitted glove assembly. One embodiment of the invention includes a knitted glove and two or more non-coplanar arrays of printed guard plates. The guard plates are small, regularly-spaced, generally uniform thickness, non-overlapping, hard polymer material members arranged in a predetermined pattern having an area parallel to a surface of the glove with major and minor dimensions. The major dimension to minor dimension aspect ratio of the guard plates is between about 3 and 1. The overall abrasion resistance of the glove assembly is substantially greater than an abrasion resistance of the knitted glove without the guard plates.
Depending on application, abrasion resistance can range from low intensity rubbing typical of gloves repeatedly worn and laundered, to high intensity abrasion (high loading and/or high speed) such as for gloves worn to provide protection in, for example, motorcycle riding. It is noted that the fabrics of the present invention can be heat resistant, which is meant to include fabrics that are relatively heat tolerant and heat insulating.
Adding cut resistant plates 2 to the gloves 3, as is done in this invention, will substantially improve the cut resistance and other mechanical properties. The cut resistance can be further increased by adding hard fillers, such as ceramic beads or glass beads, to the resin used to construct the plates 2. Also the thickness of the plates can be adjusted to provide a balance between overall glove weight and the desired level of slash resistance.
The present invention is an alternative way of making gloves that incorporate the essential features of SuperFabric® technology without the processing costs associated with making SuperFabric® sheets into gloves. These gloves are made by printing guard plates 2 directly onto the surface of a finished knitted or woven glove 3. The resulting glove assembly 1 has comparable abrasion resistance to gloves made from SuperFabric® sheets without the extra costs associated with sewing in the SuperFabric® patches. Although in some embodiments there may be some modest reduction in cut resistance due to the stretchability of the knitted glove, the gloves of the present invention offer improved comfort compared to typical gloves made from SuperFabric® sheets because of this stretchability afforded by the knitted substrate.
In one embodiment of the present invention, cut resistant plates 2 are used with a sufficiently tight gap that it is improbable or impossible for a blade to slash through the glove without cutting the plates. In another embodiment, wear resistant plates 2 are used and these can dramatically improve the lifetime of the glove. Additionally, a relatively soft dot (not shown) can be printed on top of the cut-resistant 2 plates for enhanced grip properties if desired. Alternatively, a dip coating can be applied over the plates 2. However, for some applications, the surface properties of the hard plates 2 may be preferred.
In one embodiment of the present invention, the base fabric of the knitted gloves 3 is nylon. In other embodiments, polyester, aramid, ultra high molecular weight polyethylene or blends of these materials are used. In still another embodiment, the base fabric comprises a blend of aramid and thin steel wires.
Having rigid plates with tight gaps 5 as shown in
Plurality of plates 2 are non-overlapping and are arrayed and affixed on the outer surface 4 of the knitted glove 3. Plates 2 define a plurality of gaps 5 between adjacent plates 2. Gaps 5 are continuous and inter-linking and each has a selected width so that the glove assembly 1 retains flexibility while simultaneously inhibiting objects from abrading directly against and degrading the glove's substrate 3. The glove 3 can be printed in several stages. For example, after a glove such as 3 is placed on a former plate such as 50, plates 2 can be printed on the opposite sides during separate printing steps. The gaps 5 between the plates 2 can be significantly smaller than the largest plate dimension when the gloves are in the unstretched state.
For example, plates 2 can have any polygonal shape such as a square, rectangle, octagon, or a non-regular polygon shape. Plates 2 can also have any curved shape such as a circle, ellipse, or a non-regular curved shape. Plates 2 can also be embodied as a composite shape or combination of any regular or non-regular polygon and/or any regular or non-regular curved shape.
In one embodiment of the present invention the ratio of the major dimension of the guard plate 2 to the minor dimension of the guard plate is between 1 and about 3. This is a preferred range, because horizontal aspect ratios greater than about 3 may result in plates that are more prone to cracking and are more prone to creating too much stress on the fabric. In other embodiments of the invention the guard plates 2 can have horizontal aspect ratios outside this range.
In one embodiment of the present invention the ratio of the major dimension of the guard plate to the thickness the guard plate is between 3 and about 10. This is a preferred range, because vertical aspect ratios greater than about 10 would result in plates that are more prone to cracking and vertical aspect ratios less than about 3 would be difficult to produce in a screen printing operation. In other embodiments of the invention the guard plates 2 can have vertical aspect ratios outside this range.
Gaps 5 are continuous due to the non-overlapping characteristics of plates 2. Gaps 5 also have a width that can be approximately uniform or non-uniform. However, generally, the gap 5 width is in the range of approximately 4 to 20 mils, which is the same range provided for plate thickness. In other embodiments, both gap 5 width and plate thickness is in the approximate range of 4 to 40 mils. The co-extending ranges for gap 5 width and plate thickness have been found to be an appropriate compromise between adequate flexibility and adequate mechanical strength against outside forces (i.e. abrasion, wear, cut and tear resistance) as well as providing optional heat resistance. Other embodiments of the invention have dimension outside these ranges.
As noted above, the knitted gloves can be printed by mounting the gloves on a flat hand former 50 such as that shown in
In some embodiments of the invention, a second, third or even more screen printing stages or steps are applied. As shown in the embodiment of glove assembly 1 illustrated in
In some embodiments such as those shown in
Embodiments having guard plates 2 in the thumb though forefinger area are shown in
The glove assembly 1 can be given a 3-D shape to improve comfort by printing the glove on a flat former (such as 50 and 52), only partially curing the resin while it is on the flat former, then removing the glove from the flat former and placing it on a former (not shown) having a 3-D shape corresponding to the desired shape of the portion of the glove with the plates 2 (e.g., hand-shaped). Upon fully curing the resin at least, some of the 3-D shape can be retained by the glove assembly 1. This 3-D effect can alternatively be created by using a dipping operation where nitrile, polyurethane or some other elastomer is applied to the glove assembly 1 while the glove is on a 3-D former (not shown). Curing the elastomer while on the former causes the 3-D shape to be retained by the glove assembly 1. In embodiments where an elastomer is applied, the final full cure of the resin can be carried out before or after the dipping operation.
Abrasion is a complex phenomenon or process and is influenced, for examples, by the types of materials that are being abraded, the surface characteristics, the relative speed between surfaces, lubrication, and the like. There exist many standardized abrasion tests designed to reflect many varied abrasion conditions. One typical test is the ASTM D 3884. In this test, two round-shaped wheels with specified surface characteristics apply pressure and rotate on the surface of the test sample with a given speed under a predetermined load (e.g. up to 1000 g). Test results are given either as the number of cycles for the fabric to wear through or as the fabric's weight loss after a fixed number of cycles.
Unfortunately, standardized abrasion tests are often limited due to the limited loading level and speed that can be applied against test fabric. Due to these limitations, other tests are developed to more closely simulate real world conditions. For example, one test can comprise washing gloves continuously in a washing machine containing rocks. In another example, gloves can be wrapped around a concrete weight and thrown from a speeding vehicle in order to test gloves suitable for wear by motorcycle riders and the like.
In some embodiments, the affixed plates enhance the abrasion and wear resistance of the base glove fabric by a enhancement factor F. An enhancement factor F is the ratio of abrasion and/or wear resistance of the fabric assembly of the glove to that of the knitted fabric. Thus, for example, assuming the abrasion resistance of the flexible substrate is 50 cycles on a Taber test and the abrasion resistance of the composite knit glove assembly is 500, then the enhancement factor is given by F=10. It is noted that the enhancement factor F can be the ratio of any measurement that is associated or correlated with abrasion and/or wear resistance.
The enhancement factor can be influenced by selecting various substrate fabrics, guard plate shape and dimensions such as thickness, gap width, plate diameter or maximum dimensions. The enhancement factor can generally range from 2 to 200 depending on various selections made. In other embodiments, the enhancement factor can range from 3 to 100, 3 to 10, 10 to 50, and 12 to 30, respectively.
The present invention offers a number of advantages over known gloves such as those having printed rubber material dots on the knitted gloves. One major improvement of the present invention is the increase in both abrasion resistance, cut and puncture resistance from using a geometry where the gaps between plates are smaller than the largest plate dimension. Using smaller gaps will generally enhance abrasion resistance since a larger area of the fabric will be covered. Using gaps sufficiently small that extended straight lines between plates are avoided improves both the abrasion and slash resistance since it will reduce the chances of any sharp edges penetrating the fabric. Using a gap smaller than likely puncturing object, will provide puncture resistance against those objects. Using multiple layers of the gloves can further enhance the puncture resistance. In some embodiments of the present invention, the width of the gaps, when the glove is unstretched, is between 4 and 75 percent of the size of the largest plate dimension. In other embodiments, the width of the gaps, when the glove is unstretched, is between 4 and 20 percent of the size of the largest plate dimension. In other embodiments of the invention the dimensions can be outside these ranges.
A second major advantage of the present invention is the use of a cut resistant plate. The plates used in the present invention provide slash protection due either to the inherent hardness of the resin used to construct the plate or to hard fillers added to the resin (or from a combination of both effects). Using cut resistant plates increases the real-world abrasion resistance as well as the slash resistance, since the cut resistant plates will prevent sharp edges of rocks, for example, from cutting into the gloves.
In the present invention, the plate material is applied in a wet form and slightly permeates and affixes to outer surface 4. Plate material includes resins such as epoxy resins, phenol-based resins, and other like substances. Such materials can require heat or ultraviolet curing.
Plate materials can be resins such as epoxy or phenol based resins that are capable of being solid or hard. It is generally preferred that plate material has tensile strength higher than about 100 kgf/cm2 (typical epoxy tensile strength when cured of approximately 700 kgf/cm2). It is also generally preferred that the plate hardness be higher than about Shore D 10. In some embodiments, additives can be added to the resins in order to increase abrasion, wear and/or slash resistance when appropriate. Examples of additives include alumina or titanium particles or ceramic or glass beads. Resin materials can also be specifically selected for their heat resistant properties.
In some embodiments of the present invention, an additional layer of plate material can be applied to the outer surface of the printed glove either by a printing operation or by dip coating. This material can be chosen to be polyurethane, nitrile, silicone, plastisol, or other elastomeric material for improved grip properties. In some embodiments the material will go between the gaps in the guard plates to form a bond with the underlying knitted fabric of the base glove layer. In one embodiment, the diameter of the elastomeric material is applied as dots with a diameter between 10 and 500 mils and with gaps between 10 and 500 mils.
In one embodiment of the present invention, plate dimensions are selected so that plate maximum dimension is in the range of approximately 20 to 200 mils. In another embodiment, the plates are shaped as polygons such as equilateral hexagons; curved shapes; or composite shapes arrayed in a pattern with gap widths between adjacent plates in the range of 4 to 100 mils. In another embodiment, the plate thickness is in the range of 4 to 100 mils. In other embodiments, plate thickness and gap width is in the range of 4 to 20 mils. Other embodiments of the invention have other dimensions and features.
It is sometimes desirable to enhance the abrasion and/or resistance of one or more entire glove surfaces. Alternately, abrasion and/or slash enhancement can be limited to selected locations on the glove, such as the fingers area or the palm area. These various print patterns can be achieved by the appropriate selection of a screen in the screen printing operation. The plates formed during the several printing steps can also be positioned sufficiently close to one another as to provide an essentially seamless characteristic.
Another desirable feature of the present inventions is that the glove assembly is considered attractive. The plates can be colored to match or contrast with the glove's fabric substrate. Also, the plates can be arrayed in attractive patterns. It is also possible that plate patterns and/or colors can be selected to form images or lettering due to the small yet discrete characteristics of the affixed plates. The affixed plates can also be made to be heat insulating.
Various embodiments of protective material and methods of manufacturing the protective material that can be used in connection with the gloves described herein are described in commonly owned U.S. Pat. No. 6,962,739, titled SUPPLE PENETRATION RESISTANT FABRIC AND METHOD OF MAKING, filed Jul. 6, 2000, U.S. Pat. No. 7,018,692, entitled PENETRATION RESISTANT FABRIC WITH MULTIPLE LAYER GUARD PLATE ASSEMBLIES AND METHOD OF MAKING THE SAME, filed Dec. 21, 2001, U.S. Patent Application Publication No. 20040192133, entitled ABRASION AND HEAT RESISTANT FABRICS, Ser. No. 10/734,686, filed on Dec. 12, 2003, U.S. Patent Application Publication No. 20050170221, entitled SUPPLE PENETRATION RESISTANT FABRIC AND METHOD OF MAKING, Ser. No. 10/980,881, filed Nov. 3, 2004, and U.S. Patent Application Publication No. 20050009429, entitled FLAME RETARDANT AND CUT RESISTANT FABRIC, Ser. No. 10/887,005, filed Nov. 3, 2004, all herein incorporated by reference in their entirety. The plate printing methods and plate configurations, dimensions and other features shown in these patent documents can be incorporated into the invention described herein.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.