TECHNICAL FIELD OF THE INVENTION

The present invention relates to molten metal splash protective fabrics.

BACKGROUND OF THE INVENTION

Ferrous/non-ferrous metals and their alloys, such as steel, stainless steel etc., have a melting temperature above 1200° Celsius. When the aforementioned metals in their molten state with such high temperatures splash on a garment, the garment gets immediately destructed. Further, it has been observed at rare occasions that the splashes of molten ferrous metals, such as iron, or non-ferrous metals, such as aluminium, copper, zinc, lead, tin, nickel, and magnesium, and their alloys adhere to the protective fabrics. Due to the hot stuck metal, there is immediate heat transfer between the hot metal and a person wearing the protective fabric and also immediate destruction of the fabric. Aluminium, the most common non-ferrous alloy, is known for its easy“staying stuck” behavior in the clothes of wearers, typically smelters. Molten aluminium has an operating temperature of 7000° Celsius to 8000° Celsius, which is enough to cause severe bums to the smelters.

Conventional protective garments are made of a fabric having a blend of flame- retardant fibers and wool for protection against ferrous metals and nonferrous metals, mainly aluminium. Such protective fabrics must withstand high thermal shocks and hot molten metal splashes to avoid being destroyed, and at the same time, maintain the structure thereof so as to prevent hot metal from entering into the wearer’s clothing.

The International Organization for Standardization has set up codes for checking quality of a protective fabric against metal splashes. ISO 11612:2015 is one of the codes specified by the ISO for protective clothing. It is observed that the conventional fabric, having a blend of flame-retardant fibers and wool, passes Έ” code of ISO 11612 which is for iron. However, the fabric fails to comply with requirements of ISO 11612“D” Code which is for aluminium. Molten iron is not as viscous as molten aluminium. Thus, conventional fabrics pass“E” code but fails in“D” code. Further, due to use of wool, the yams of such protective fabric require use of particular spinning system for their manufacturing. Typically, a worsted spinning system is used to manufacture yams of aforementioned conventional protective fabrics. However, such yarns cannot be manufactured using a ring spinning system setup. Furthermore, the fabrics having a blend of flame-retardant fibers and wool fibers tend to be ineffective to withstand splashes of molten metals, and show lower repellence characteristics allowing the molten metal to stick to the garment of a wearer. This can cause serious burns to the worker.

Therefore, there is need of a molten metal splash protective fabric that alleviates the aforementioned drawbacks of conventional protective fabrics, and safeguards a wearer from hot molten metal splashes.

SUMMARY OF THE INVENTION The present invention relates to a molten metal splash protective fabric. The fabric consists of an intimate blend of vinyl on fibers ranging from 80% to 90% w/w of the fabric and cellulosic fibers ranging from 10% to 20% w/w of the fabric. In an embodiment, the vinylon fibers range from 85% to 90% w/w of the fabric and cellulosic fibers ranging from 10% to 15% w/w of the fabric. The cellulosic fibers are selected from the group consisting of cotton, tencel, and excel.

The fabric is a textile woven fabric, preferably twill woven fabric.

The fabric is made of a plurality of double yams, and has weight ranging from 280 to 400 grams per square meter. The present invention further envisages a garment made of the molten metal splash protective fabric. DETAILED DESCRIPTION OF THE INVENTION

Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention, and are not intended to define or limit the scope of the invention. References in the specification to“an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment. The present invention relates to a molten metal splash protective fabric.

The molten metal splash protective fabric consists of an intimate blend of vinylon fibers ranging from 80% to 90% w/w of the fabric and cellulosic fibers ranging from 10% to 20% w/w of the fabric. The vinylon fibers are flame-retardant fibers.

In an embodiment, the vinylon fibers range from 85% to 90% w/w of the fabric and cellulosic fibers range from 10% to 15% w/w of the fabric.

In an embodiment, the flame-retardant vinylon fibers include flame-retardant polyvinyl alcohol fibers.

The cellulosic fibers can be natural fibers or manmade fibers. In an embodiment, the cellulosic fibers are selected from the group consisting of cotton, tencel, excel, and any combinations thereof.

The protective fabric is air permeable and moisture/vapour permeable. The protective fabric reduces perspiration and provides greater comfort to a wearer for long period of time.

The protective fabric has a moisture vapour transmission rate (MVTR) of more than 1000 gm/square meter/day when tested pursuant to ASTM E-96-05. The protective fabric has high abrasion resistance of more than 300000 revolutions when tested pursuant to ISO 12947/2 or ASTM D4966.

The protective fabric is woven with textile weaves such as twill or satin textile weaves. In an embodiment, the fabric is twill woven. The protective fabric is made of a plurality of double yarns, each double yarn has yarn count ranging from 2/16s Ne to 2/24s Ne. The use of double yams imparts good luster and strength while maintaining the same resultant count as that of the single yarn.

The weight of the fabric ranges from 280 grams per square meter to 400 grams per square meter.

The fabric is dimensionally stable (i.e., display reduced stretching or shrinking), and optionally further comprise other functional durable finishes such as an anti microbial, water and oil repellent, stain release finishes and the like, without affecting protective performance. The fabric confers thermal protection against molten metal and has aesthetic properties like colour, breathability and/or durability.

The fabric confers thermal protection against the molten metal including ferrous metals, non-ferrous metals, and alloys thereof such as copper, zinc, lead, tin, aluminum, cryolite, and nickel, or magnesium. The method of manufacturing the protective fabric of the present invention is elaborated in subsequent paragraphs.

The method comprises the following steps.

Initially, an intimate blend of flame-retardant vinylon fibers in an amount of at least 80% to 90% by weight of a total protective fabric weight and cellulosic fibers in an amount of at least 10% to 20% by weight of the total protective fabric weight is spun through a ring spinning system to obtain yarns. In the embodiment, the flame-retardant vinylon fibers includes flame-retardant polyvinyl alcohol fibers and the cellulosic fibers is selected from group consisting of cotton, tencel, excel, and the like.

The yarns are then processed through a weaving process to obtain the fabric of the present invention. Typically, the yams are woven with textile weaves such as twill or satin textile weaves. In an embodiment, the yams are twill woven to obtain a fabric.

The method further includes a step of wet processing. The wet processing includes the sub-step of singeing, wherein a singeing machine, through a gas burner, burns out any protruding fibers for improving the resistance to pilling and imparting lustre to the fabric.

The wet processing includes the sub-step desizing. In the desizing step, the fabric is exposed to oxidative desizing for a period of at least 8 hours to remove any added impurities like size, spinning oil etc. The wet processing further includes a sub-step of washing. The fabric is washed with hot water to remove impurities.

The wet processing further includes a sub-step of dyeing, wherein the fabric is padded with a vat dye and an auxiliary (PDPS - Pad dry - pad steam process) and dried at 1400C. In an embodiment, the fabric is developed on a continuous dyeing range (CDR) machine by treating with a reducing agent and steaming for a prescribed time of 1 minute. Then fabric may be oxidized with H ₂ 0 ₂ , washed and dried on a vertical drying range (VDR) at 800C.

The wet processing further includes a sub-step of finishing, wherein the fabric is treated with a hydrophilic softener on a stenter machine which provides a soft hand feel to the fabric. Any other durable features like anti-microbial finish, water and oil repellents, and stain release agents may be incorporated. The wet processing further includes a sub-step of sanforizing, wherein the fabric is shrunken in length and width to provide a permanent dimension to the fabric.

The wet processing further includes a sub-step of garmenting, wherein the fabric, is garmented with flame retardant trims. The present invention further discloses a garment made of the fabric elaborated in foregoing paragraphs. More specifically, the garment is made of the molten metal splash protective fabric consisting of an intimate blend of vinylon fibers ranging from 80% to 90% w/w of the fabric and cellulosic fibers ranging from 10% to 20% w/w of the fabric. The garment protects a wearer from hot splashes of molten metal.

In an embodiment, the vinylon fibers in the garment range from 85% to 90% w/w of the fabric of the garment and cellulosic fibers in the garment range from 10% to 15% w/w of the garment. The weight of the garment ranges from 280 gsm to 400 gsm. The garment confers thermal protection against molten metal and has aesthetic properties like colour, breathability and/or durability.

The protective fabric and the garment made thereof comply with various requirements of International Organization for Standardization (ISO) for protective clothing. The ISO is an international standard setting body composed of representatives from various national standards organizations.

The protective fabric complies with the requirements of ISO 11611 and ISO 11612 for Code“D” and Code Έ”. At least the fabric having 280 gsm weight complies with these codes.

The protective fabric complies with the requirements of ISO 11612: 2015, clause 7.4 molten aluminum splash, ISO 9185: 2007 for Code“D”. The protective fabric having weight of 280 gsm complies with the requirements of Code“Dl” the fabric having 400 gsm complies with the requirements of Code“D3”. The protective fabric complies with the requirements of ISO 11612: 2015, clause 7.5 molten iron splash ISO 9185: 2007 for Code“E”. The protective fabric having weight of 280 gsm complies with the requirements of Code Έ2” and the fabric having weight of 400 gsm complies with the requirements of Code Έ3”. The protective fabric also complies with the requirements of ISO 15025 and

ASTM D 6413. The code ISO 15025 relates to test method for protection against heat and flame for limited flame spread. ASTM D6413 relates to standard test method for flame resistance of textiles (Vertical Test)

For testing the fabric to determine the level of protection against spatters of molten metal, a membrane (having properties similar to human skin) is attached to the reverse of the fabric sample. Subsequently, sequentially rising quantities of molten metal (for the D value - molten aluminium and for the E value - molten iron) are splashed on the sample. The quantity of molten metal which deforms the membrane is determined. For example, if a fabric sample sustains molten iron splash of up to 120 gm without showing deformation in membrane, the fabric is considered to be code“El” competent.

Example 1:

Pursuant to a performance standard ISO 11612: 2015, Clause 7.5 molten iron splash ISO 9185: 2007, Iron metal having more than 97% purity, a pouring temperature of 1400 ± 20°C, a pouring height of 225 mm, and a specimen angle of 75° to the horizontal shows the following:

According to an embodiment, the protective fabric complies with the requirements of ISO 11612: 2015, clause 7.5 molten iron splash ISO 9185: 2007 for Code Έ”. The protective fabric having weight of 280 gsm complies for Code Έ2” and the fabric having weight of 400 gsm complies for Code“E3” at 400 gsm.

Example 2:

Pursuant to a performance standard: ISO 11612: 2015, Clause 7.4 molten aluminium Splash, Aluminium having a pouring temperature of 780 ± 20°C, a pouring height of 225 mm, and a specimen angle of 60° to the horizontal shows the following:

According to the embodiment, the protective fabric complies with the requirements of ISO 11612: 2015, clause 7.4 molten aluminum splash, ISO 9185: 2007 for Code“D”. The protective fabric having 280 gsm weight complies for Code“Dl” and the fabric having weight 400 gsm complies for Code“D3”.

The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.