Patent Description:
Cut resistant fabrics provide cut protection, tear and abrasion resistance against sharp or jagged objects and are widely used in various applications. The applications range from making protective clothing, industrial gloves, helmets, to high strength ropes, and packaging metal and glass articles. Such cut resistant fabrics are composed of polymeric and non-polymeric fibers, such as high tenacity polyester, nylon, and gel spun fibers, and thermoplastic polyethylene fibers, such as Ultra High Molecular Weight Polyethylene (UHMWPE) fibers.

For manufacturing a cut resistant fabric, the polymeric and non-polymeric fibers and the polyethylene fibers are treated with fillers and combined with raw materials in a spinning process to obtain cut resistant fibers. The cut resistant fibers are woven or knitted to obtain the cut resistant fabric. Document <CIT> discloses a cut resistant fabric comprising UHMWPE and a wollastonite filler.

The Applicant has identified several technical challenges associated with the cut resistant fabric comprising UHMWPE fiber. Through applied effort, ingenuity, and innovation, many of these identified challenges have been overcome by developing solutions that are included in embodiments of the present disclosure, many examples of which are described in detail herein.

The illustrative embodiments of the present disclosure relate to a cut resistant fabric used for manufacturing industrial gloves having high cut resistance and wear comfort for users. The cut resistant fabric comprises an Ultra High Molecular Weight Polyethylene (UHMWPE) material, such as UHMWPE fibers or a UHMWPE resin, and a sheet shaped wollastonite filler. The sheet shaped wollastonite filler is treated with a coupling agent and mixed with the UHMWPE material. The sheet shaped wollastonite filler has a thickness of less than <NUM> micrometers (µm).

In some embodiments, the sheet shaped wollastonite filler has a length less than <NUM> and a width less than <NUM>.

In some embodiments, the sheet shaped wollastonite filler has a Mohs hardness higher than <NUM>, and a silica content higher than <NUM>%.

In some embodiments, the coupling agent comprises at least one of gamma-Aminopropyltriethoxysilane (KH550), and polyorganosiloxane (Penta-<NUM>).

In an example embodiment, a proportion of the sheet shaped wollastonite filler in the cut resistant fabric ranges from <NUM>% to <NUM> % by volume.

In an example embodiment, a method for preparing a cut resistant fiber is provided. The method comprises providing a sheet shaped wollastonite filler having a thickness of less than <NUM>. The method comprises treating the sheet shaped wollastonite filler with a coupling agent at a first predefined temperature to obtain a uniform solution and mixing the uniform solution with a fiber solution comprising UHMWPE resin at a second predefined temperature.

In an example embodiment, obtaining the uniform solution comprises mixing a dispersing agent with the sheet shaped wollastonite filler to obtain a mixture of the dispersing agent and the sheet shaped wollastonite filler and adding the mixture of the dispersing agent and the sheet shaped wollastonite filler to a white oil. The white oil being a fiber spinning solvent.

In some embodiments, the sheet shaped wollastonite filler has a length less than <NUM>, and a width less than <NUM>.

In an example embodiment, the first predefined temperature is <NUM>° Celsius (C) and the second predefined temperature is <NUM>.

In an example embodiment, the coupling agent comprises at least one of gamma-Aminopropyltriethoxysilane (KH550), and polyorganosiloxane (Penta-<NUM>).

The above summary is provided merely for purposes of summarizing some example embodiments to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above-described embodiments are merely examples and should not be construed to narrow the scope of the disclosure in any way. It will be appreciated that the scope of the disclosure encompasses many potential embodiments in addition to those here summarized, some of which will be further described below.

Some embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments are shown. Indeed, the disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. The terms "or" and "optionally" are used herein in both the alternative and conjunctive sense, unless otherwise indicated. The terms "illustrative" and "exemplary" are used to be examples with no indication of quality level.

Fabrics used for various industrial applications, such as industrial gloves, high strength ropes, packaging glass and metal articles and personal protective equipment have high strength, durability and cut resistance. The fabrics are generally made of polyester fibers or polyethylene fibers including Ultra High Molecular Weight Polyethylene (UHMWPE) fibers that provide strength, and flexibility to the fabrics. Such cut resistant fabrics are typically manufactured using composite yarns that include the UHMWPE fibers blended with other materials for hardness of the fabrics. For instance, the UHMWPE fibers are mixed with glass fibers to achieve high cut resistance levels. The UHMWPE fibers are also blended with rod-shaped hard fillers for example, short fibers or nano rods during a spinning process. For many applications, the UHMWPE fibers are also mixed with stainless-steel material to achieve a predetermined hardness for the fabrics.

However, blending the UHMWPE fibers with glass fibers, rod-shaped fibers or stainless-steel material make the fabrics brittle and cause the fabrics to crack or break during manufacturing and use by a user. The breaking of the fabrics during manufacturing, on many instances, causes damage to a manufacturing equipment resulting in increased cost. Industrial gloves made from such fabrics are generally uncomfortable in wearing and cause allergy to the user. Further, manufacturing the fabrics with such composite yarns is time-consuming and complex.

Various example embodiments described in the present disclosure relate to a cut resistant fabric that is hard, flexible and provides wear comfort to users. The cut resistant fabric is composed of UHMWPE resin and a sheet shaped wollastonite filler. The UHMWPE resin are combined with the sheet shaped wollastonite filler in the spinning process at a predefined temperature to obtain the cut resistant fabric. The sheet shaped wollastonite filler has a predefined dimension, such as a sheet shape, and a thickness less than <NUM> micrometers (µm). The sheet shaped wollastonite filler has a length less than <NUM> and a width less than <NUM>. The sheet shaped wollastonite filler has a Mohs hardness, which is indicative of scratch resistance of a surface, higher than <NUM> and a silica content higher than <NUM> % by volume. In an example, the thickness of the sheet shaped wollastonite filler is selected to be lower than the thickness of the UHMWPE fibers to allow mixing of the filler with the UHMWPE resin.

The predefined dimension allows an anisotropic arrangement of the sheet shaped wollastonite filler with the UHMWPE resin that facilitates even distribution and mixture of the filler with the UHMWPE resin. Further, the sheet shaped wollastonite filler reduces breakage in the fabric by reducing overall stress distribution of the UHMWPE resin during manufacturing or knitting and improves shear strength of the fabric. The sheet shaped wollastonite filler shows improved mixing with other raw materials during the spinning process and glove manufacturing.

In an example embodiment, prior to mixing with the UHMWPE resin, the sheet shaped wollastonite filler is treated with a silane coupling agent. The silane coupling agent provides improved bonding and compatibility between the filler and the UHMWPE resin.

The fabric comprising the UHMWPE resin and the sheet shaped wollastonite filler exhibits flexibility and strength and is used for various applications, such as glove knitting, industrial ropes and handling glass and metal articles. The fabric is also light-weighted and finds application in armor design, such as vehicle armor and protective helmets and vests.

The details regarding manufacturing of the fabric using an assembly line system is described with reference to subsequent figures and description.

The components illustrated in the figures represent components that may or may not be present in various example embodiments described herein such that embodiments may include fewer or more components than those shown in the figures while not departing from the scope of the disclosure.

Turning now to the drawings, the detailed description set forth below in connection with the appended drawings is intended as a description of various example configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts with like numerals denoting like components throughout the several views. However, it will be apparent to those skilled in the art of the present disclosure that these concepts may be practiced without these specific details.

<FIG> illustrates an assembly line <NUM> for manufacturing a cut resistant fabric in accordance with an example embodiment of the present disclosure. As shown in <FIG>, the assembly line <NUM> comprises a continuous extruder <NUM> having a hopper or an inlet <NUM>, an extruder die <NUM>, a metering pump <NUM>, a spinneret <NUM>, a quenching and extraction bath <NUM>, an oven <NUM>, and a roller <NUM>.

In an example, the extruder die <NUM> comprises a mandrel <NUM> disposed concentrically to the extruder die <NUM> within the extruder die <NUM>, and an extrusion screw <NUM> disposed on the mandrel <NUM>. The mandrel <NUM> is rotatable along an axis within the extruder die <NUM>. In an example embodiment, the continuous extruder <NUM> comprises multiple heaters (not shown in the figure) placed on an inner surface of the extruder die <NUM> to heat materials fed to the continuous extruder <NUM>. The extruder die <NUM> has outlets <NUM>-<NUM> and <NUM>-<NUM> and each of the outlets <NUM>-<NUM> and <NUM>-<NUM> is coupled to the metering pump <NUM>. An outlet of the metering pump <NUM> is coupled to the spinneret <NUM>. Although <FIG> illustrates a single spinneret <NUM> coupled to the metering pump <NUM>, in various other embodiments there may be multiple spinnerets, each spinneret being coupled to the metering pump <NUM>. The assembly line <NUM> is arranged such that the spinneret <NUM> is coupled to the quenching and extraction bath <NUM> and the quenching and extraction bath <NUM> is coupled to the oven <NUM>. The assembly line <NUM> comprises the roller <NUM> positioned adjacent to the oven <NUM>.

For manufacturing a cut resistant fabric, an Ultra High Molecular Weight Polyethylene (UHMWPE) material, such as UHMWPE fibers or a UHMWPE resin of a specific dimension or a particle size are dissolved into a fiber spinning solvent. The UHMWPE resin may be in form of either granules, pellets or a powder. In an example embodiment, the UHMWPE resin, in a powdered form, is dissolved into the fiber spinning solvent. The particle size of the UHMWPE resin is within a range from <NUM> to <NUM> and molecular weight is in a range from <NUM> x <NUM><NUM> to <NUM> x <NUM><NUM>. The fiber spinning solvent, for instance, is a white oil or a paraffin oil. After dissolving the UHMWPE resin in the fiber spinning solvent, a fiber solution is obtained. The fiber solution has a consistent viscosity. The fiber solution is fed to the continuous extruder <NUM> via the inlet <NUM>.

In an example, a filler, for instance a sheet shaped wollastonite filler is treated with a silane coupling agent, prior to mixing the filler with the fiber solution. The sheet shaped wollastonite filler is illustrated in <FIG> in accordance with an example embodiment of the present disclosure. <FIG> show a microscopic view of the composition and structure of the sheet shaped wollastonite filler. <FIG> shows a lower resolution view <NUM> of the composition and structure of the sheet shaped wollastonite filler and <FIG> shows a higher resolution view <NUM> of the sheet shaped wollastonite filler.

The sheet shaped wollastonite filler has a predefined dimension having a thickness of less than <NUM> micrometers (µm), a length of less than <NUM>, and a width of less than <NUM>. The thickness of the sheet shaped wollastonite filler is selected such that the sheet shaped wollastonite filler can be properly mixed with the UHMWPE fibers. Further, the sheet shaped wollastonite filler has a Mohs hardness higher than <NUM>, and a silica content higher than <NUM>% by volume. The Mohs hardness of <NUM> or higher provides a predetermined hardness to the fabric for manufacturing cut resistant fabrics. Such hardness improves shear modulus of constituent fibers thereby increasing the shear strength of the fabrics. The sheet shaped wollastonite filler having the predefined dimension provides an anisotropic arrangement of the filler with the UHMWPE resin. Such an arrangement provides improved strength to the cut resistant fabric and reduces breakage and stress distribution of fibers during the spinning process.

The silane coupling agent is one of a gamma-Aminopropyltriethoxysilane (KH550) agent, and a polyorganosiloxane (Penta-<NUM>) agent. Treating the sheet shaped wollastonite filler with the silane coupling agent improves compatibility and interfacing between the sheet shaped wollastonite filler and the UHMWPE resin.

Referring to <FIG>, a uniform solution is obtained by mixing the sheet shaped wollastonite filler and the silane coupling agent. A dispersing agent is also added to the uniform solution to improve stability of the uniform solution and surface compatibility of the sheet shaped wollastonite filler and the silane coupling agent. In an example, a content of the dispersing agent within the uniform solution is in a range of <NUM> % to <NUM>% by volume. The uniform solution is fed to the continuous extruder <NUM> via the inlet <NUM>. The uniform solution having the sheet shaped wollastonite filler and the silane coupling agent is mixed and blended with the fiber solution comprising the UHMWPE resin and the fiber spinning solvent in the continuous extruder <NUM>.

In operation, the mandrel <NUM> and the extrusion screw <NUM> of the continuous extruder <NUM> rotate to blend the fiber solution and the uniform solution. The mixing and blending is performed in a continuous manner based on the rotation and a mixture of the fiber solution and the uniform solution is being pushed towards the outlets <NUM>-<NUM> and <NUM>-<NUM> of the continuous extruder <NUM>. In an example, the heaters (not shown in the figure) disposed within the inner surface of the extruder die <NUM> heat the mixture to a temperature, for instance, <NUM>° Celsius (°C) for coherent blending. In an example, the mixture is blended and heated at <NUM> for two hours in the extruder die <NUM>.

The mixture, after the blending, is supplied to the metering pump <NUM> via the outlets <NUM>-<NUM> and <NUM>-<NUM> of the extruder die <NUM>. In an example, the outlets <NUM>-<NUM> and <NUM>-<NUM> have narrower tubes than the extruder die <NUM> and some pressure is applied to the mixture to reach the metering pump <NUM> via the outlets <NUM>-<NUM> and <NUM>-<NUM>. In an example, the metering pump <NUM> segregates the mixture into two or more portions and supplies each portion of the mixture to a spinneret, such as the spinneret <NUM>. In an example embodiment having the multiple spinnerets coupled to the metering pump <NUM>, each spinneret receives a portion of the mixture from the metering pump <NUM>.

At the spinneret <NUM>, the mixture is filtered to remove impurities from the mixture and then supplied to the quenching and extraction bath <NUM>. The mixture is delivered to water pipes disposed within the quenching and extraction bath <NUM> to lower the temperature of the mixture and form a gel. The gel comprises solvents, such a paraffin oil and other solvent, such as xylene. After the gel passes through the water pipes and before entering the oven <NUM>, the xylene is extracted from the gel to lower a paraffin content in the gel. Thereafter, at the oven <NUM>, the gel is heated at a high temperature, for instance, <NUM> for drying the gel to remove the paraffin content. A drawing operation of fibers is performed through the roller <NUM>. In various example embodiments, the drawing operation is performed, at a draw ratio of <NUM>. Towards the end of the drawing operation, a yarn <NUM> of fibers is obtained. The fibers obtained have high cut and abrasion resistance property and are woven or knitted to obtain the cut resistant fabric. In various example embodiments, the fibers have cut resistance to achieve European EN388 <NUM> Level C or American Society for Testing and Materials (ASTM) F2292 A3 level and are suitable for manufacturing <NUM>-gauge industrial gloves.

<FIG> is a flow chart illustrating a method <NUM> for manufacturing a cut resistant fiber in accordance with an example embodiment of the present disclosure. Referring now to block <NUM>, the method of manufacturing the cut resistant fiber comprises providing a sheet shaped wollastonite filler having a thickness of less than <NUM> micrometers (µm). The sheet shaped wollastonite filler provides hardness to the fiber and reduces breakage in the fiber during manufacturing. At block <NUM>, the sheet shaped wollastonite filler is treated with a coupling agent at a first predefined temperature to obtain a uniform solution. In an example embodiment, the coupling agent is a silane coupling agent, such as one of a gamma-Aminopropyltriethoxysilane (KH550) agent, and a polyorganosiloxane (Penta-<NUM>) agent. The first predefined temperature is <NUM>.

At block <NUM>, the method for manufacturing the cut resistant fiber comprises mixing the uniform solution with an Ultra High Molecular Weight Polyethylene (UHMWPE) resin at a second predefined temperature. The second predefined temperature is <NUM>. The uniform solution is obtained by mixing a dispersing agent with the sheet shaped wollastonite filler and adding a fiber spinning solvent, such as the white oil. In an example, the sheet shaped wollastonite filler has a length less than <NUM>, and a width less than <NUM>.

In an example embodiment, the cut resistant fiber is obtained by mixing the fiber solution comprising the UHMWPE resin and the uniform solution, where the sheet shaped wollastonite filler has a thickness of <NUM>, a length of <NUM> and a width of <NUM>. In such a cut resistant fiber, a content of the sheet shaped wollastonite filler is <NUM>% by volume. For the cut resistant fiber, a hot drawing temperature is <NUM> and the drawing ratio is <NUM>.

Claim 1:
A cut resistant fabric comprising:
an Ultra-High Molecular Weight Polyethylene (UHMWPE) material; and
a sheet shaped wollastonite filler, the sheet shaped wollastonite filler being treated with a silane coupling agent and mixed with the UHMWPE material, wherein a thickness of the sheet shaped wollastonite filler is less than <NUM> micrometers (µm).