Pantyhose Article Having Ultra-High Molecular Weight Polyethylene and Method for Manufacturing Thereof

This Patent Cooperation Treaty application claims the benefit of priority of U.S. Provisional Application 63/341,160 filed on May 12, 2022, and Canadian Patent Application No. 3,185,681 filed on Dec. 23, 2022, which are incorporated herein in their entirety.

The present disclosure generally relates to a pantyhose article having ultra-high molecular weight polyethylene (UHMWPE) and a method for manufacturing thereof, and more particularly, to a pantyhose article having multiple different knits, including at least two knits having UHMWPE.

Traditional knit fabrics for manufacture of hosiery products (such as pantyhose, stockings, socks, and tights) include nylon in combination with elastane (e.g., Lycra™ of Spandex™). However, these fabrics tend to rip or tear when subjected to frictional forces. It was observed that sheer hosiery products (e.g., 30 denier and below) made using these fibers are very fragile. They can easily be ripped by hand, foot or hang nail, and are generally considered disposable. Therefore, there remains a need for commercially viable sheer (low denier) elastic knits that are not easy to rip.

Ultra-high molecular weight polyethylene (UHWMPE) fiber is considered as an ideal reinforcing component due its high impact strength, low density, low elongation at break, resistance to corrosive chemicals, low moisture absorption, and low coefficient of friction. The knits including UHMWPE fibers in combination with stretch fibers such as Spandex, nylon or polyester have shown increased rip resistance. However, UHMWPE fiber is very expensive, and its quality varies considerably from supplier to supplier and from batch to batch. Lower quality UHMWPE fiber may result in defects, such as yarn ring or barre, which leads to damaged hosiery that cannot be used in inventory and thus becomes waste.

Therefore, there remains a need for commercially viable knits for making hosiery that allow utilizing a lower amount, and/or lower grade UHMWPE fiber while maintaining the desired rip resistance and durability.

According to one aspect, there is provided a pantyhose article that includes a first tubular member. The first tubular member includes a first panty portion and a first tubular leg portion, the first panty portion extending from a waist end of the pantyhose article to a bottom end of the first panty portion and the first tubular leg portion defining a first leg cavity and extending from a top end thereof, corresponding to the bottom end of the first panty portion, to a first foot end of the first tubular leg portion, the first tubular leg portion comprising a first principal sub-portion and a first transitional sub-portion, the first principal sub-portion extending from a first thigh region of the first tubular leg portion to the first foot end and the first transitional sub-portion extending from the top end of the first tubular leg portion to the first thigh region of the first tubular leg portion, the first principal sub-portion being formed of a first knit comprising a first ultra-high molecular weight polyethylene (UHMWPE) fiber and at least one first companion fiber and the first transitional sub-portion being formed of a second knit comprising a second UHMWPE fiber and at least one second companion fiber, the first knit being different from the second knit.

According to another aspect, there is provided a method for manufacturing a pantyhose article. The method includes forming a first tubular member having a first panty portion extending from a waist end of the pantyhose article to a bottom end of the first panty portion and a first tubular leg portion defining a first leg cavity and extending from a top end thereof, corresponding to the bottom end of the first panty portion, to a first foot end of the first tubular leg portion, the first tubular leg portion comprising a first principal sub-portion and a first transitional sub-portion, the first principal sub-portion extending from a first thigh region of the first tubular leg portion to the first foot end and the first transitional sub-portion extending from the top end of the first tubular leg portion to the first thigh region of the first tubular leg portion and extending circumferentially about the first tubular leg portion, the first principal sub-portion being formed of a first knit comprising a first ultra-high molecular weight polyethylene (UHMWPE) fiber and at least one first companion fiber and the first transitional sub-portion being formed of a second knit comprising a second UHMWPE fiber and at least one second companion fiber, the first knit being different from the second knit. The method also includes forming a second tubular member having a second panty portion extending from the top end of the pantyhose article to a bottom end of the second panty portion being aligned with the bottom end of the first panty portion and a second tubular leg portion defining a second leg cavity and extending from a top end thereof, corresponding to the bottom end of the second panty portion, to a second foot end of the second tubular leg portion, the second tubular leg portion comprising a second principal sub-portion and a second transitional sub-portion, the second principal sub-portion extending from a second thigh region of the second tubular leg portion to the second foot end and the second transitional sub-portion extending from the top end of the second tubular leg portion to the second thigh region of the second tubular leg portion and extending circumferentially about the second tubular leg portion, the second principal sub-portion being formed of the first knit comprising the first UHMWPE fiber and the at least one first companion fiber and the second transitional sub-portion being formed of the second knit comprising the second UHMWPE fiber and the at least one second companion fiber. The method further includes cutting the first panty portion along a longitudinal direction thereof to form first longitudinal edges therein and cutting the second panty portion along a longitudinal direction thereof to form second longitudinal edges therein, joining the first longitudinal edges of the first panty portion to the second longitudinal edges of the second panty portion to form a panty tube defining a panty cavity for receiving a lower torso of a wearer, the panty cavity being in fluid communication with the first leg cavity of the first tubular leg portion and the panty cavity being in fluid communication with the second leg cavity of the second tubular leg portion, and joining the longitudinal edges of the first panty portion to a first edge of a gusset and joining the longitudinal edges of the second panty portion to a second edge of the gusset.

In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments. However, one skilled in the art will understand that the invention may be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments. Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises”, “comprising”, “includes” and “including” are to be construed in an open, inclusive sense, that is, as “including, but not limited to.” Further, headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. Further, as used in this specification and the appended claim, the term “about” has the meaning reasonably ascribed to it by a person of ordinary skill in the art when used in conjunction with a stated numerical value or range, i.e., denoting somewhat more or somewhat less than the stated value or range, to within a range of ±20% of the stated value; ±19% of the stated value; ±18% of the stated value; ±17% of the stated value; ±16% of the stated value; ±15% of the stated value; ±14% of the stated value; ±13% of the stated value; ±12% of the stated value; ±11% of the stated value; ±10% of the stated value; ±9% of the stated value; ±8% of the stated value; ±7% of the stated value; ±6% of the stated value; ±5% of the stated value; ±4% of the stated value; ±3% of the stated value; ±2% of the stated value; or ±1% of the stated value.

As used herein, and unless the context dictates otherwise, the following terms have the meanings as specified below.

The term “UHMWPE” stands for ultra-high molecular weight polyethylene, also known as high-modulus polyethylene (HMPE), or high-performance polyethylene (HPPE).

The term “colored UHMWPE” means UHMWPE that has been colored (e.g., made non-white) by a non-additive coloring process.

The term “fiber” as used herein refers to a single origin base material made up of one or more filaments. It has an elongate body, the length dimension of which is much greater than the transverse dimensions of width and thickness.

The term “filament” as used herein refers to a single fibril of material that can be on its own a fiber or can be combined with other filaments to create a multifilament fiber. A single fiber may be formed from just one filament or from multiple filaments.

The term “microfilament” as used herein refers to a filament having a denier of 5 or less.

The term “denier” used herein refers to a unit of weight indicating the fineness of fiber filaments. It can be measured in mass in grams per 9,000 meters of fiber. A lower denier indicates a finer fiber, and a higher denier indicates a thicker or heavier fiber.

The term “decitex (dtex)” as used herein refers to an alternate unit of weight indicating the fineness of fiber filaments. It can be measured in mass in grams per 10,000 meters.

The term “tensile strength” as used herein relates to the durability of the garment and is measured by the maximum stress that a material can withstand while being stretched or pulled before breaking. It is measured as force per unit area and can be expressed in units of gram force (gf) and centi-newton (cN) per dtex.

The term “elongation” as used herein refers to the stretch of individual fibers and composite fibers which results in the elasticity of the final embodiment of the present disclosure. Elongation is measured as a percentage of the starting length.

The term “natural fiber” as used herein refers to class of fibers obtainable from material of natural sources.

The term “synthetic fiber” as used herein is used to class of fibers made by humans. Synthetic fibers comprise for example polymeric material, synthesized by polymerization of monomers, fibers obtained by regeneration of natural fibers, for instance after dissolution in a solvent, and glass fibers.

Term “stretch fiber” as used herein refers to class of fibers that, upon application of a force, is stretchable to a stretched at least about 130% of its original dimension without breaking,

The term “non-stretch fiber” refers to class of fibers which is substantially non-elastic with little or no elongation.

The term “high performance fiber” as used herein refers to class of fibers having high values of tenacity greater, for example greater than 10 g/denier, such that they lend themselves for applications where high abrasion and/or cut resistance is important. Typically, high performance fibers have a very high degree of molecular orientation and crystallinity in the final fiber structure.

The term “elastomeric fiber” as used herein refers to a fiber which has a break elongation in excess of 100% and which when stretched and released, retracts quickly and forcibly to substantially its original length.

The term “thermoplastic fiber” as used herein refers to class of fibers obtained from polymer that is plastic or deformable, melts to a liquid when heated and freezes to a brittle, glassy state when cooled sufficiently.

The term “abrasion resistant fiber” as used herein refers to class of fibers that inhibits abrasion of the material that it is proximate to.

The term “knit” as used herein refers to the fabric created by combining one or more fibers on a flat or circular knitting machine.

The term “gauge” as used herein refers to the number of needles on the knitting machine. A high gauge knitting machine (32 gauge and above) is required to produce sheer hosiery like sheer tights, stockings and trouser socks and a low gauge knitting machine (18 to 32 gauge) is used to produce heavier garments like leggings, bodysuits, socks, shirts and other active wear. Gauge is also used to refer to the knit that has been produced by a machine: in other words, a knit made on a 32 gauge machine is a 32 gauge knit.

The term “plating” as used herein refers to a technique of knitting two fibers together in two distinct layers. Where one fiber stays in the back, behind the front fiber despite being knit in the same stitch.

The term “serving” as used herein refers to the process of spinning two fibers together to produce a composite fiber.

The term “non-additive” as used herein refers to coloring, typically dyeing, methods that do not increase the total denier of the fiber.

“Tensile properties” are properties measured when a material is subjected to stretching forces, and also the properties measured when the stretching forces are removed. Example tensile properties include but are not limited to tensile strength at break, percent elongation to break, modulus of elasticity, toughness or tensile energy to break, permanent set, tensile load at specified elongations, etc. Tensile properties of polymer fibers can be determined for example by standard test methods such as ASTM D2256/D2256M-21, “Tensile Properties of Yarns by the Single-Strand Method”.

The term “barre” as used herein is defined as unintentional, repetitive visual of continuous bars or stripes usually parallel to the courses of circular knit fabric.

Various aspects described herein involve UHMWPE fibers for preparing knitted fabrics and methods for forming the same.

In some embodiments, the UHMWPE fiber has high impact strength, low density, low elongation at break, resistance to corrosive chemicals, low moisture absorption, and/or low coefficient of friction. In other aspects, the material is self-lubricating and highly resistant to abrasion and odor.

In some embodiments, the UHMWPE fiber has a weight average molecular weight (M) of at least about 200,000. In some embodiments, the UHMWPE fiber has a weight average molecular weight (M) ranging from about 300,000 to about 7,000,000, from about 700,000 to about 5,000,000, or from about 900,000 to about 4,000,000. A molecular weight distribution of the UHMWPE fiber, that is the ratio of the weight average molecular weight (M) to a number average molecular weight (M) of the UHMWPE fiber is of about 5.0 or less, about 4.0 or less, or about 3.0 or less.

In some embodiments, the UHMWPE fiber is a monofilament. In some other embodiments, the UHMWPE fiber comprises a plurality of microfilaments. In some embodiments, each of the microfilaments in the UHMWPE has a denier of about 5 of less, about 4 or less, about 3 or less, about 2.5 or less, about 2 or less, about 1.5 or less, about 1 or less, or about 0.5 or less.

The UHMWPE fiber may include any suitable number of microfilaments. In some embodiments, the UHMWPE fiber comprises 2 to 400 microfilaments, 10 to 300 microfilaments, 10 to 50 microfilaments, 5 to 50 microfilaments, 5 to 25 microfilaments, or 20 to 200 microfilaments. In some embodiments, the UHMWPE fiber comprises 5, 7, 10, 15, 20, 25, 30, 35, 40, 45, or 50 microfilaments.

The UHMWPE fiber may be of any denier suitable for pantyhose. In some embodiments, the UHMWPE fiber has a denier ranging from about 10 to about 250. In some embodiments, the UHMWPE fiber has a denier ranging from about 10 to about 60. In some embodiments, the UHMWPE fiber has a denier of about 10, about 15, about 20, about 25, about 30, about 40, about 50, about 60, about 70, about 75, about 80, about 90, about 100, about 110, about 120, about 125, about 130, about 140, about 150. In some embodiments, the UHMWPE fiber has a denier of 50 or less.

In some embodiments, the UHMWPE fiber is a high strength fiber. In some embodiments, the UHMWPE fiber has a tensile strength (i.e., tenacity) of at least 20 cN/dtex, at least 25 cN/dtex, at least about 30 cN/dtex, at least about 35 cN/dtex, at least about 40 cN/dtex, at least about 45 cN/dtex, at least about 50 cN/dtex, or at least about 60 cN/dtex. In some embodiments, the UHMWPE fiber has a tensile strength of about 26 cN/dtex, about 28 cN/dtex, about 30 cN/dtex, about 32 cN/dtex, about 36 cN/dtex, about 40 cN/dtex, about 45 cN/dtex, or about 50 cN/dtex.

In some embodiments, the UHMWPE fiber has a modulus of about 1000 cN/dtex or greater, about 1100 cN/dtex or greater about 1200 cN/dtex or greater, about 1300 cN/dtex or greater, about 1400 cN/dtex or greater, about 1500 cN/dtex or greater, about 1600 cN/dtex or greater. In some embodiments, the UHMWPE fiber has a modulus of about 1400 cN/dtex, about 1420 cN/dtex, about 1450 cN/dtex, about 1500 cN/dtex, or about 1360 cN/dtex.

In some embodiments, the UHMWPE fiber allows an elongation of no more than about 10%, no more than about 8%, no more than about 5%, no more than about 4%, no more than about 3.5%, no more than about 3%, no more than about 2.5%, no more than about 2%, or no more than about 1.5%.

In some embodiments, the UHMWPE fiber has a breaking force of about 10 N or greater, about 11 N or greater, about 12 N or greater, about 13 N or greater, about 14 N or greater, about 15 N or greater, about 16 N or greater, about 18N or greater, or about 20 N or greater.

In some embodiments, the UHMWPE fiber has a breaking work of at least about 100N·mm, at least about 110 N·mm, at least about 120 N·mm, at least about 130 N·mm, at least about 140 N·mm, at least about 150 N·mm, at least about 160 N·mm, or at least about 170 N·mm.

In some embodiments, the UHMWPE fiber is a colored UHMWPE fiber comprising a dye. In some embodiments, the dye has a color selected from black, blue, grey, red, blue, brown, yellow, green, orange, and nude.

In some embodiments, the UHMEPE fiber comprises multiple microfilaments which are not twisted. In some other embodiments, to keep the filaments together and to increase strength and reduce pilling, the UHMWPE fiber is twisted. In some embodiments, the UHMWPE fiber has a twists per inch (TPI) between 1 to 30, between 1 to 20, between 1 to 10, between 1 to 5, between 4 and 25, between 6 and 20, or between 8 and 16. In some embodiments, the UHMWPE fiber has a TPI of 1. In some embodiments, the UHMWPE fiber has a TPI of 2. In some embodiments, the UHMWPE fiber has a TPI of 3. In some embodiments, the UHMWPE fiber has a TPI of 4. In some embodiments, the UHMWPE fiber has a TPI of 5. In some embodiments, the UHMWPE fiber has a TPI of 6. In some embodiments, the UHMWPE fiber has a TPI of 8. In some embodiments, the UHMWPE fiber has a TPI of 10. In some embodiments, the UHMWPE fiber has a TPI of 12. In some embodiments, the UHMWPE fiber has a TPI of 15. In some embodiments, the UHMWPE fiber has a TPI of 16. In some embodiments, the UHMWPE fiber has a TPI of 18. In some embodiments, the UHMWPE fiber has a TPI of 20. In some embodiments, the UHMWPE fiber has a TPI of 25. In some embodiments, the UHMWPE fiber has a TPI of 30.

In various aspects, the UHMWPE fibers described herein can be produced according to methods described in U.S. publication no. US20220056620.

In some embodiments, the UHMWPE fiber has a variation of the color along the length of said UHMWPE fiber. In some embodiments, a variation of the color along the length of the UHMWPE fiber is less than ±2.5%, less than ±3%, less than ±3.5%, less than ±4%, less than ±5%, less than ±6%, less than ±7%, less than ±8%, or less than ±9%, or less than ±10%.

The use of UHMWPE fiber provides benefits to knit such as cooling effect, light weight, moisture wicking, and/or antimicrobial. The tensile properties of the UHMWPE fiber also provide increased resistance to ripping, snagging or otherwise wearing out or failing of the knit. In some embodiments, the UHMWPE fiber has a variation of the denier along the length of said UHMWPE fiber. In some embodiments, a variation of the denier along the length of said UHMWPE fiber is less than ±2.5%, less than ±3%, less than ±3.5%, less than ±4%, less than ±5%, less than ±6%, less than ±7%, less than ±8%, or less than ±9%, or less than ±10%. In some embodiments, the UHMWPE fiber has a variation of the diameter along the length of said UHMWPE fiber is less than ±2.5%, less than ±3%, less than ±3.5%, less than ±4%, less than ±5%, less than ±6%, less than ±7%, less than ±8%, or less than ±9%, or less than ±10%. In some embodiments, the UHMWPE fiber has a cross sectional shape substantially resembling a circle. In some embodiments, the UHMWPE fiber has a cross sectional shape substantially resembling an oval. In some embodiments, the UHMWPE fiber has a cross sectional shape substantially resembling a stadium. In some embodiments, the UHMWPE fiber has a cross sectional shape substantially resembling an ellipse. In some embodiments, the UHMWPE fiber has a cross sectional shape which remains substantially constant along the length of the fiber.