DESC:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to a process for making yarn. In particular, the present disclosure relates to a process of making a tarn with improved tenacity.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0004] Extrusion processors, particularly from textile domains, have been blending polypropylene (PP) and high-density polyethylene (HDPE) to improve the tensile strength of yarn or fibres, which have exhibited higher mechanical properties than yarns made entirely of PP or HDPE. HDPE is said to improve crystallisation rate of PP melt, which results in an overall increase in the degree of crystallinity and, consequently, in tensile strength of yarns made of the blended polymer.
[0005] Nano-clay has been used as a reinforcement in polymer composites to increase the mechanical and thermal properties in comparison to compared to base polymers. Coppola et. al. demonstrated that addition of nano-clay significantly increases the draw ability and elastic modulus of polyethylene fibres. However, the dispersion and compatibility of the nano-clay in polyolefins is critical to achieving improved mechanical properties.
[0006] The use of Maleic anhydride-modified polypropylene (MAPP) and Maleic anhydride-modified polyethylene (MAPE) are well known in making polymer-clay nanocomposites. It has been found that the higher molecular weight maleic anhydride-modified polyolefins, having a weight average molecular weight of at least 10,000, preferably at least 40,000, provides much better mechanical properties, such as strength and temperature resistance. If the weight average molecular weight is too low, e.g., below about 5,000, the maleic anhydride-modified polyolefin will act as a plasticizer and decrease the properties of the polyolefin in the nanocomposite; and if the weight percentage of the maleic anhydride (measured as a weight of maleic anhydride only) is too high, e.g., above about 5% by weight, based on the weight of the maleic anhydride-modified polyolefin, the maleic anhydride-modified polyolefin will not be compatible with neat polyolefins; if too low, e.g., below about 0.2% by weight, the resin has limited compatibility with the modified montmorillonite.
[0007] The prior art in the cited publications above have several limitations. Firstly, since nano-clay particles have no particular affinity towards PP or HDPE, it is expected that nano-clay particles would be evenly dispersed in the PP and HDPE matrix after mixing in the extrusion process. However, since, at temperatures between 80-130 degrees centigrade only the HDPE phase is stretched, the presence of the nano-clay will have no particular benefit, but will have detrimental effects in two particular ways
• the cost of nano-clay being high, the overall cost of the tapes will be needlessly increased; and
• the specific gravity of nano-clays (>2 g/cm3) being much higher than PP or HDPE (0.9 g/cm3 and 0.95 g/cm3 respectively), the denier of the tape will increase, leading to lower tenacity in tapes.
[0008] There is, therefore, a requirement in the art for a polymer yarn and a process to make the polymer yarn that can ensure that the nano-clay is dispersed primarily in the HDPE phase to provide a polymer yarn with high tenacity.

OBJECTS OF THE PRESENT DISCLOSURE
[0009] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.
[0010] It is an object of the present disclosure to provide a polymer composite yarn with improved tenacity.
[0011] It is an object of the present disclosure to provide a polymer composite yarn, which is easy to make.
[0012] It is an object of the present disclosure to provide a cost-effective polymer composite yarn with improved tenacity.

SUMMARY
[0013] The present disclosure relates, in general, to a process for making yarn. In particular, the present disclosure relates to a process of making a yarn with improved tenacity.
[0014] An aspect of the present disclosure pertains to a polymer composite yarn. The polymer composite yarn includes a polypropylene (PP) and a high-density polyethylene (HDPE) to form a polymer blend, and the HDPE comprises nano-clay particles and Maleic Grafted HDPE (MAPE).The PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn.
[0015] In an aspect, the nano-clay particles may be in range of 0.5-5 percent by weight of the polymer composite yarn.
[0016] In an aspect, the MAPE may be in range of 1-10 percent by weight of the polymer composite yarn.
[0017] In an aspect, the polymer composite yarn may comprise a dispersing agent, wherein the dispersing agent comprises any or combination of polyethylene waxes, polyvinyl alcohol, polyethylene glycol, stearic acid, propyltrimethoxysilane, poly acrylic acid, and likes.
[0018] In an aspect, the dispersing agent may be in a range of 0.1-2 percent by weight of the polymer composite yarn.
[0019] In an aspect, the nano-clay particles and the MAPE may be melt blended in the HDPE.
[0020] In an aspect, the PP and the HDPE may be dry blended using tumble mixing to make the polymer composite yarn.
[0021] In an aspect, the polymer composite yarn may be stretched, using one or more rollers, at a temperature in a range 85-130 degrees centigrade, and with a draw ratio in a range 9-16.
[0022] In an aspect, the polymer composite yarn may be subjected to crystallization and quenching processes.
[0023] Yet another aspect of the present disclosure pertains to a system for fabricating a polymer composite yarn. The system includes a mixer configured to dry mix a polypropylene (PP) and a high-density polyethylene (HDPE). The PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn. An extruder operatively configured with the mixer, and the extruder is configured to receive the mixture of PP and HDPE to produce the polymer composite yarn.
[0024] In an aspect, the system may include one or more rollers operatively configured with the extruder, and configured to stretch the polymer composite yarn, and the stretching of the polymer composite yarn is carried out at a temperature in a range 85-130 degree centigrade and with a ratio in a range 9-16.
[0025] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0026] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.
[0027] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
[0028] FIG. 1 illustrates an exemplary representation of a system for fabricating a polymer composite yarn, in accordance with an embodiment of present disclosure.

DETAILED DESCRIPTION
[0029] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[0030] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[0031] The present disclosure relates, in general, to a process for making yarn. In particular, the present disclosure relates to a process of making a tarn with improved tenacity.
[0032] The present disclosure elaborates upon a polymer composite yarn. The polymer composite yarn includes a polypropylene (PP) and a high-density polyethylene (HDPE) to form a polymer blend, and the HDPE comprises nano-clay particles and Maleic Grafted HDPE (MAPE). The PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn.
[0033] In an embodiment, the nano-clay particles can be in range of 0.5-5 percent by weight of the polymer composite yarn.
[0034] In an embodiment, the MAPE can be in range of 1-10 percent by weight of the polymer composite yarn.
[0035] In an embodiment, the polymer composite yarn can comprise a dispersing agent, wherein the dispersing agent comprises any or combination of polyethylene waxes, polyvinyl alcohol, polyethylene glycol, stearic acid, propyltrimethoxysilane, and poly acrylic acid.
[0036] In an embodiment, the dispersing agent can be in a range of 0.1-2 percent by weight of the polymer composite yarn.
[0037] In an embodiment, the nano-clay particles and the MAPE can be melt blended in the HDPE.
[0038] In an embodiment, the PP and the HDPE can be dry blended using tumble mixing to make the polymer composite yarn.
[0039] In an embodiment, the polymer composite yarn can be stretched, using one or more rollers, at a temperature in a range 85-130 degrees centigrade, and with a draw ratio in a range 9-16.
[0040] In an embodiment, the polymer composite yarn can be subjected to crystallization and quenching processes.
[0041] Yet another embodiment of the present disclosure pertains to a system for fabricating a polymer composite yarn. The system includes a mixer configured to dry mix a polypropylene (PP) and a high-density polyethylene (HDPE). The PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn. An extruder operatively configured with the mixer, and the extruder is configured to receive the mixture of PP and HDPE to produce the polymer composite yarn.
[0042] In an embodiment, the system can include one or more rollers operatively configured with the extruder, and configured to stretch the polymer composite yarn, and the stretching of the polymer composite yarn is carried out at a temperature in a range 85-130 degree centigrade and with a ratio in a range 9-XX.
[0043] FIG. 1 illustrates an exemplary representation of a system for fabricating a polymer composite yarn, in accordance with an embodiment of present disclosure.
[0044] As illustrated, a system 100 for fabricating a polymer composite yarn. The system includes a mixer 102 configured to dry mix a polypropylene (PP) and a high-density polyethylene (HDPE). The PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn. An extruder 104 operatively configured with the mixer, and the extruder is configured to receive the mixture of PP and HDPE to produce the polymer composite yarn. The system 100 can include one or more rollers 106 operatively configured with the extruder 104, and configured to stretch the polymer composite yarn.
[0045] In an embodiment, the polymer composite yarn can include a polypropylene (PP) and a high-density polyethylene (HDPE) to form a polymer blend, and the HDPE comprises nano-clay particles and Maleic Grafted HDPE (MAPE). The PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn. The nano-clay particles can be in range of 0.5-5 percent by weight of the polymer composite yarn. The MAPE can be in range of 1-10 percent by weight of the polymer composite yarn.
[0046] In an embodiment, the polymer composite yarn can comprise a dispersing agent, wherein the dispersing agent comprises any or combination of polyethylene waxes, polyvinyl alcohol, polyethylene glycol, stearic acid, propyltrimethoxysilane, poly acrylic acid, and likes. The dispersing agent can be in a range of 0.1-2 percent by weight of the polymer composite yarn. The nano-clay particles and the MAPE can be melt blended in the HDPE. The PP and the HDPE can be dry blended using tumble mixing to make the polymer composite yarn. The polymer composite yarn can be stretched, using one or more rollers, at a temperature in a range 85-130 degree centigrade, and with a draw ratio in a range 9-16. The polymer composite yarn can be subjected to crystallization and quenching processes.
[0047] Tenacity of drawn polymer yarns and fibres has correlations with attributes of the yarn such as its molecular weight and its drawing limit. Generally, yarns that are able to be drawn higher exhibit higher tenacity, and yarns with higher molecular weight exhibit higher tenacity. Higher molecular weight polymers generally have a higher number of polymer chain entanglements, and hence are able to withstand higher pulling force before the chains separate. However, the effect of molecular weight on tenacity of polymer yarns exists up to a limit, since due to the higher number of entangled polymer chains, it is also difficult to stretch the polymer yarn. Hence, while higher molecular weight improves the tenacity of the polymer yarn, the tenacity of the yarn cannot be further increased by merely increasing the molecular weight. Thus, it can be appreciated that providing a polymer for a yarn, where the polymer has a sufficiently high molecular weight, but with fewer chain entanglements would be preferable.
[0048] In an embodiment, the present disclosure provides a polymer composite, where the polymer composite matrix contains added nano-clay. In another aspect, the present disclosure provides a high tenacity polymer composite tape yarn (also referred as polymer composite yarn) made of a blend of polymers and nano-clay. The tape yarn can be used as a generic term to denote an oriented product that has a high aspect ratio and can include articles such as fibres, filaments, monofilaments, multifilament, tapes, yarn, and the like. The polymer composite is made of a blend of a polypropylene (PP) and a high density polyethylene (HDPE) compound. The HDPE compound can include nano-clay particles and Maleic Grafted HDPE, the use of which helps in drawing of the tapes to large draw ratio, thereby enabling substantial increase in the tensile strength of the polymer composite yarn.
[0049] The addition of nano-clay results in a polymer composite, where the polymer chains can be able to slide over the nano-clay particles in the matrix, resulting in local disentanglements in the polymer matrix, allowing for higher tenacity of the polymer and, consequently, a higher draw. The term polypropylene can be used to include polypropylene homopolymers, polypropylene copolymers, blends of polypropylenes and combinations thereof. The PP used can have a wide range of Melt Flow Index (MFI) from fractional MFI to about 30g/10min at 230 °C and 2.16 Kg applied pressure.
[0050] In another embodiment, as referenced herein, the term high density polyethylene (HDPE) can be used to include HDPE homopolymers, HDPE copolymers, blends of HDPE and combinations thereof. In an exemplary embodiment, the specific gravity of the polymer is about 0.94 g/cm3 and higher, preferably being greater than 0.95 g/cm3. HDPEs having an MFI in the range of 0 – 20g/10minat 230 °C and 2.16 Kg applied pressure can be used for the proposed polymer yarn.
[0051] In another embodiment, as referenced herein, the term polymer blend can include a combination of any of the PP and the HDPE. The compatibility of the polymer blend can reduce at higher weight percentages of HDPE. The weight % of HDPE added varies between 1 and 50% and can be selected depending on the mechanical properties of the blend polymer desired. Thorough shear mixing of the PP and the HDPE melt can be preferred during extrusion process of producing a yarn of the polymer blend, in order to obtain a homogenous blend.
[0052] Nano-clays can be referred to nanoparticles of layered mineral silicates. The nano-clay, of the present disclosure can be any of different classes of clays such as, without being limited by, montmorillonite, bentonite, kaolinite, hectorite and halloysite. In another embodiment, the average particle size of the nano-clay used is about 100 nm and lower. Further, about 90% of the total particle count of the nano-clay used is preferred to be about the stated size. Maleic Anhydride Grafted HDPE (MAPE) can be used production of the proposed polymer composite, which preferably possesses a higher molecular weight of average value of about 20,000 and higher and an MFI in the range of about 0 – 10g/10min.
[0053] Moreover, in interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ….and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
[0054] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0055] The proposed invention provides a polymer composite yarn with improved tenacity.
[0056] The proposed invention provides a polymer composite yarn, which is easy to make.
[0057] The proposed invention provides a cost-effective polymer composite yarn with improved tenacity.
,CLAIMS:1. A polymer composite yarn, the polymer composite yarn comprising:
a polypropylene(PP) and a high-density polyethylene (HDPE)to form a polymer blend, and the HDPE comprises nano-clay particles and Maleic Grafted HDPE (MAPE); wherein the PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn.
2. The polymer composite yarn as claimed in claim 1, wherein the nano-clay particles are in range of 0.5-5 percent by weight of the polymer composite yarn.
3. The polymer composite yarn as claimed in claim 1, wherein the MAPE is in range of 1-10 percent by weight of the polymer composite yarn.
4. The polymer composite yarn as claimed in claim 1, wherein the polymer composite yarn comprises a dispersing agent, wherein the dispersing agent comprises any or combination of polyethylene waxes, polyvinyl alcohol, polyethylene glycol, stearic acid, propyltrimethoxysilane, and poly acrylic acid.
5. The polymer composite yarn as claimed in claim 4, wherein the dispersing agent is in a range of 0.1-2 percent by weight of the polymer composite yarn.
6. The polymer composite yarn as claimed in claim 1, wherein the nano-clay particles and the MAPE are melt blended in the HDPE.
7. The polymer composite yarn as claimed in claim 1, wherein the PP and the HDPE are dry blended using tumble mixing to make the polymer composite yarn.
8. The polymer composite yarn as claimed in claim 1, wherein the polymer composite yarn is stretched, using one or more rollers, at a temperature in a range 85-130 degrees centigrade, and with a draw ratio in a range 9-16.
9. A system for fabricating a polymer composite yarn, the system comprising:
a mixer configured to dry mix a polypropylene (PP) and a high-density polyethylene (HDPE), wherein the PP is in a range of 10-90 percent by weight of the polymer composite yarn, and the HDPE is in a range of 10-90 percent by weight of the polymer composite yarn;
an extruder operatively configured with the mixer, and the extruder is configured to receive the mixture of PP and HDPE to produce the polymer composite yarn.
10. The system as claimed in claim 9, wherein the system comprising one or more rollers operatively configured with the extruder, and configured to stretch the polymer composite yarn, wherein the stretching of the polymer composite yarn is carried out at a temperature in a range 85-130 degree centigrade and with a ratio in a range 9-16.