FIELD OF THE INVENTION:

[0001] The present invention generally relates to breathable fabrics. More particularly, the present invention relates to a breathable composite sheet which is aesthetically appealing and provides high strength and durability.

BACKGROUND OF THE INVENTION:

[0002] Artificial leather, well known in the art, is used as a substitute for leather in various items such as upholstery, garments, clothing and fabrics. In particular, composite structures, for example, artificial leather are used in various ways as decorative and upholstery materials. In recent times, the concern for new functionalities or properties, customized design incorporation of the artificial leather has grown immensely in order to increase the value of the end products and to fulfill the client’s requirements. Accordingly, research to improve the comfort in upholsteries and other areas of users' direct contact with materials such as garments and clothing has increased significantly. Breathability is increasingly the most desired feature in furniture and automotive upholstery; especially as ventilated seats are being introduced.

[0003] Typically, the artificial leathers are coated fabrics which are generally produced by forming a porous layer on a fabric base, followed by subjecting the surface to a suitable treatment to provide color and shape to the layered material which are similar to those of natural leather. In particular, a PolyVinyl Chloride (PVC) coating is applied to a fabric substrate by using a direct coating process or a transfer process. The artificial leather includes pores to form breathable artificial leather with increased breathability. These breathable artificial leathers are suitable for use in, but not limited to, garments, clothing, foot wears, automotive interiors, for example seat covering material, because breathability assures enhanced seat comfort and prevents perspiration on a vehicle seat covered with the material or a user’s body covered with that material.

[0004] There are a number of problems associated with the conventional leathers. In the current market breathable artificial leatherettes are provided which have large holes to achieve improved breathability. This creates an aesthetic that cannot be avoided and hence is a drawback for the breathability feature. Moreover, the holes are large enough for liquids, dust and other particles to pass through thereby blocking the holes and reducing the breathability of the artificial leather. Further, some of the conventional breathable artificial leathers are based of Poly Urethane (PU), a material which is not successful in locations with high moisture or water contact. A phenomenon called hydrolysis occurs and damages the PU based artificial leather. Additionally, the conventional breathable artificial leathers present low abrasion resistance. Similar limitations are there in the household appliances and fashion products which include conventional artificial leather.

[0005] In view of the above limitations of the conventional approaches, leatherette and methods, there exists a need to develop an improved approach, a breathable composite sheet and method which would in turn address a variety of issues including, but not limited to, pass through of liquids and dust through the end product, interference with the aesthetic appeal of the product, low abrasion resistance and which provides enhanced moisture management, and increased strength and durability. Further, it is desired to develop a breathable composite sheet which can be used in areas and locations of high moisture and applications that have regular contact with water. Moreover, it is desired to develop a breathable composite sheet which possesses invisible nano-perforations which results in reduced permeability and prevents entry of dust particles.

[0006] Thus, the above-described deficiencies of conventional approaches, leatherette and methods thereof, are merely intended to provide an overview of some of the problems of conventional approaches and are not intended to be exhaustive. Other problems with conventional approaches, leatherette and methods and their corresponding benefits of the various non-limiting embodiments described herein may become further apparent upon review of the following description.

SUMMARY OF THE INVENTION:

[0007] The following presents a simplified summary of the invention to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

[0008] It is, therefore, an object of the present invention to provide a breathable composite sheet which involves nano-perforations which in turn, brings various benefits such as anti wick properties, as well as breathability.

[0009] It is another object of the present invention to provide a breathable composite sheet which is aesthetically appealing, possesses abrasion resistance and has high strength and durability due to nano-perforations being small enough to not hamper the material properties.

[0010] It is another object of the present invention to provide a breathable composite sheet which facilitates the benefit of avoiding pass through of liquids and dust through the end product.

[0011] It is another object of the present invention to provide a breathable composite sheet which provides enhanced moisture management.

[0012] It is still another object of the present invention to provide a breathable composite sheet which has very low water permeability as compared to normal perforated leatherette. Thus, the breathable composite sheet is capable to be used in areas and locations of high moisture and applications that have regular contact with water.

[0013] Accordingly, in an aspect, the present invention provides a breathable composite sheet comprising a sequentially arranged layers of skin coat, foam coat, adhesive coat and fabric from bottom to top. The layers are collectively heated and perforated by micro needling to obtain a nano-perforated composite sheet having nano-perforations of size ranging from 0.3 to 1 micron.

[0014] Accordingly, in another aspect, the present invention provides a method of preparing a breathable composite sheet.

[0015] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, details the invention in different embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS:

[0016] While the specification concludes with claims that particularly point out and distinctly claim the invention, it is believed that the advantages and features of the present invention will become better understood with reference to the following more detailed description of expressly disclosed exemplary embodiments taken in conjunction with the accompanying drawings. The drawings and detailed description which follow are intended to be merely illustrative of the expressly disclosed exemplary embodiments and are not intended to limit the scope of the present invention as set forth in the appended claims. In the drawings:

[0017] FIG. 1 illustrates a breathable composite sheet in accordance with an embodiment of the present invention;

[0018] FIG. 2 illustrates pictorial images of the exemplary (a) usual perforated breathable leatherette and (b) nano-perforated breathable leatherette in accordance with an exemplary embodiment of the present invention; and

[0019] FIG. 3 is a flow chart illustrating a method of preparing a breathable composite sheet in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION:

CALL OUT LIST
1000 Breathable composite sheet
200 nano-perforations

[0020] The exemplary embodiments described herein detail for illustrative purposes are subject to many variations in the structure and design. It should be emphasized, however, that the present invention is not limited to a particular composite sheet as shown and described herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0021] The use of terms “including,” “comprising,” or “having” and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0022] Further, the terms, “an” and “a” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0023] Referring to FIG. 1, the invention will now be described in more detail. A breathable composite sheet (1000), as shown in FIG. 1, comprises a plurality of layers of skin coat, foam coat, adhesive coat and fabric. These layers of skin coat, foam coat, adhesive coat and fabric are sequentially arranged from bottom to top.

[0024] In accordance with an embodiment of the present invention, the breathable composite sheet (1000) comprises at least 50% Polyvinyl chloride (PVC) with a ratio of plasticizer being at least 60% of PVC. Preferably, the plasticizer is Dioctyl terephthalate (DOTP).

[0025] In accordance with an embodiment of the present invention, the skin coat and the foam coat are formed from a coating composition comprising a mixture of polymer, plasticizer, stabilizer, pigments, and additives. These constituents are mixed together to obtain a homogenous paste. The polymer is Polyvinyl chloride (PVC) and the plasticizer is Dioctyl terephthalate (DOTP). The pigments are selected from, but not limited to, a group consisting of titanium dioxide, and red oxide (black oxide or yellow pigment). The additives are selected from, but not limited to, a group consisting of Antimony Trioxide, Antimony Dihydrate, and Tinuvin-P.

[0026] In accordance with an embodiment of the present invention, the coating composition comprising the mixture of polymer, plasticizer, stabilizer, pigments, and additives, is coated on a release paper and the coating composition is then heated to form the skin coat. Then, the skin coat coated on the release paper moves towards a heating oven with a desired temperature in the range of, but not limited to, 165-175°C. After passing through the oven, the skin coat is converted into a film. The coating composition is further coated on the skin coat and is then heated to form the foam coat. Then, the foam coat is passed through the heating oven having the temperature in the range of, but not limited to, 190-200°C. After passing through the oven, the foam coat is converted into a film which is composed of foam coat (middle coat) and the skin coat.

[0027] In accordance with an embodiment of the present invention, the adhesive coat is formed from a coating composition which comprises a mixture of polymer, plasticizer, stabilizer, and additives. Preferably, the polymer is Polyvinyl chloride (PVC) and the plasticizer is Dioctyl terephthalate (DOTP). Further, the additives are selected from, but not limited to, a group consisting of Antimony Trioxide, Antimony Dihydrate, and Tinuvin-P. This coating composition is coated over the foam coat in same way as foam coating is done, to form the adhesive coat. Further, a layer of fabric is pasted or laminated on to the adhesive coat. Preferably, the fabric is a polyester spun fabric.

[0028] In accordance with an embodiment of the present invention, the layers, namely, skin coat, foam coat, adhesive coat and fabric, are collectively heated at a temperature in the range of, but not limited to, 165-175°C. Preferably, the layers are heated at a temperature of 160°C. Further, the heated layers are perforated by micro needling to obtain a nano-perforated composite sheet (1000) having nano-perforations (200) of size ranging from 0.3 to 1 micron. Preferably, the nano-perforations (200) have size of around 1 micron. The composite sheet (1000) also involves texture formation such as embossing and surface treatment to provide leather like appearance.

[0029] In accordance with an embodiment of the present invention, the nano-perforated composite sheet (1000) may be of various types including, but not limited to, nano-perforated leather or leatherette, nano-perforated PVC leather, nano-perforated faux leather, nano-perforated leo leather or the like. Further, the nano-perforated composite sheet (1000) may be customized based on the user’s desire or requirement.

[0030] In accordance with an embodiment of the present invention, FIG. 2 illustrates pictorial images of the exemplary (a) usual perforated breathable leatherette and (b) the nano-perforated breathable leatherette in which the perforations are invisible to naked eye and does not inference with the aesthetic appeal of the leatherette.

[0031] In accordance with an embodiment of the present invention, the method of preparing the breathable composite sheet (1000), as shown in FIG. 3, is provided. This method is unique in a way that breathability is achieved in the composite sheet without the perforations or holes being apparent to the user. At first step of the method, a PVC based coating composition is extruded. The PVC based composition is the Polyvinyl chloride based composition. The composite sheet (1000) comprises at least 50% PVC with a ratio of plasticizer being at least 60% of PVC. Preferably, the plasticizer is Dioctyl terephthalate (DOTP).

[0032] In accordance with an embodiment of the present invention, at second step of the method, layers of skin coat, foam coat, adhesive coat and fabric are formed which are sequentially arranged from bottom to top by using the coating composition.

[0033] In accordance with an embodiment of the present invention, the layers of skin coat and foam coat are formed from a PVC based coating composition which comprises a mixture of PVC polymer, plasticizer, stabilizer, pigments, and additives. Further, the layer of adhesive coat is formed from a PVC coating composition which comprises a mixture of PVC polymer, plasticizer, stabilizer, and additives. The plasticizer is Dioctyl terephthalate (DOTP) and the pigments are selected from, but not limited to, a group consisting of titanium dioxide, and red oxide (black oxide or yellow pigment). Further, the additives are selected from, but not limited to, a group consisting of Antimony Trioxide, Antimony Dihydrate, and Tinuvin-P.

[0034] In accordance with an embodiment of the present invention, the coating composition comprising the mixture of PVC polymer, plasticizer, stabilizer, pigments, and additives is coated on the release paper and then heated at a temperature in the range of, but not limited to, 165-175°C to form the skin coat. This coating composition is further coated on the skin coat and is then heated at a temperature in the range of, but not limited to, 190-200°C to form the foam coat. Further, the coating composition comprising the mixture of polymer, plasticizer, stabilizer, and additives is coated on the foam coat, in the same way as foam coating is done, to form the adhesive coat. Thereafter, the layer of fabric is pasted on to the adhesive coat. Preferably, the fabric is a polyester spun fabric.

[0035] In accordance with an embodiment of the present invention, at third step of the method, the layers are heated at a temperature in the range of, but not limited to, 165-175°C to obtain a composite sheet. Preferably, this step of heating is performed at a temperature of 160°C to obtain the composite sheet.

[0036] In accordance with an embodiment of the present invention, at fourth step of the method, the composite sheet is perforated by micro needling to create nano-perforations (200) of size ranging from 0.3 to 1 micron. Preferably, the nano-perforations (200) are of size around 1 micron. In particular, the perforation by micro needling is performed by passing the composite sheet through a post processing machine having a die and a backing rubber support such that perforations are made between the rubber support and the composite sheet, thereby making nano-perforations (200) in the composite sheet. In other words, post processing, the composite sheet is perforated by the micro needling process on a special post processing machine. The specialty being the accurate and measured gap between each hole or perforation that ensures that the strength of the material is least affected. Also, the fact that the holes are made with a back rubber support material while being perforated, still does not show visible holes or perforations.

[0037] In accordance with an embodiment of the present invention, the winded roll of the composite sheet is lifted up from the winder and loaded on the unwinder of the post embossing machine. The nano-perforation roll or the composite sheet is set up on to the post embossing machine and the composite sheet is passed with the help of guide rolls to make perforation in between of the rubber roll and nano-perforation roll or composite sheet. The diameter of perforation needle is 0.32 micron. Thereafter, the nano-perforated composite sheet (1000) is winded on the product winder station.
EXAMPLES
The following examples are intended as illustrative and non-limiting and represent specific embodiments of the present disclosure.

Example 1: Materials and Methods
[0038] The coating composition included polymer, plasticizer, stabilizer, pigments, and additives. The polymer was Polyvinyl chloride (PVC) of B 7021 grade and procured from Vestolit, Germany. The plasticizer was Dioctyl terephthalate (DOTP) which was procured from Humade Corporation. The stabilizer was RUP-151R procured from Adeka Corporation, Japan. The pigments used were red oxide (446), black (C05), yellow pigment which were procured from BASF, USA. The additives used were Antimony Trioxide, Antimony Dihydrate 4200, and Tinuvin-P procured from Chemico Chemical, Nicknam Chemicals, and Oswal Polycam, respectively. These constituents were mixed together to obtain a homogenous paste. A release paper which is silky matt procured from Sappi and polyester spun fabric procured from XIN-LUN Company, China were also used. Table 1 below shows the specification of the coating composition constituents.

TABLE 1: Specifications of constituent of the coating composition
Constituents Specification
PVC (B 7021) K Value – 70
Viscosity – 125cm3/gm
Sieve Analysis - ?1%
Plasticizer (DOTP) Specific gravity – 0.986
Thermal stability – should be transparent
Volatile loss – 0.1% max
Thermal stability – should be transparent
Stablizer (RUP-151R) Heat stability – PVC film Should not be degrade
Pigment
(Red oxide(446), Black(C05), Yellow) Strength - 100±10%
Delta E - ?1.0 max
Additives Moisture – 0.1% max (Antimony Trioxide)
Moisture – 0.1% max (Antimony Dihydrate 4200)
Moisture – 0.5% max (Tinuvin-P)
Fabric
(Polyester spun fabric) Count – 40s/S/1
CB – polyester spun
NEPS – 40/1N/E
Release Paper
(Silky matt) Thickness – 0.16-0.18mm

Example 2: Preparation of the breathable
[0039] After preparing the coating composition in the form of homogenous paste, the release paper was used for supporting this paste and then passed through the heating oven to convert this paste into a film. The release paper was in roll form with around length of 1800 to 2000 mtr. The release paper roll was placed on unwinding station on the machine and passed through the machine up to the final stage where winding of the paper takes place. This paper may be reused for as many times till finished product quality meets the required specification. First coating of the paste or the coating composition was done through knife coater on the release paper and thickness of the coating was controlled by maintaining the gap between the release paper and the knife. Thickness was automatically controlled during production with the help of a gauge controller. The paste coated on paper was moved towards the heating oven with the temperatures of 170±5°C which was then converted into film to form the skin coat. Foam coating was done over first coating in same way as skin coating was done. Thickness of the foam coat was maintained by gap of knife and the release paper with the skin coat. This was passed through the heating oven where temperature of 195±5°C was maintained. Again this paste was converted into a film to form the middle coat or the foam coat. This film was composed of middle coat and skin coat. Third stage coating of the paste was done over the middle coat or the foam coat in similar manner as done for earlier two coats. This coating was formed as an adhesive coat which acted as adhesive to laminate the fabric. Backing fabric from the fabric unwinding station was spread on adhesive coat by using roller. The paper with all the layers of coating and fabric was passed through the heating oven at the temperature of 170±5°C, specifically at a temperature of 160°C to form the composite sheet. Thereafter, the paper was released and this was taken on paper winding station wherein paper winding happened. Similarly, the composite sheet thus released from paper was sent for product winder.

[0040] After winding the composite sheet on the winding roll, the winded roll was lifted up from the winder and loaded to the unwinder of the post embossing machine. The nano-perforation roll or the composite sheet roll was set up on to the post embossing machine and the composite sheet roll was passed with the help of guide rolls to make perforation in between of the rubber roll and nano-perforation roll or composite sheet roll. The diameter of perforation needle was 0.32 micron. These needles created nano-perforations of size ranging from 0.3 to 1 micron, preferably, 1 micron in the composite sheet. After that, the nano-perforated composite sheet is winded on the product winder station. Further, jumbo rolls of the final product or the nano-perforated composite sheet were stored for inspection of quality of the product.

TABLE 2: Coating compositions for various coatings
Coating compositions Constituents Mixing Method Specification Inspection Method
Pigment preparation Dry pigment, plasticizer, Dispersing agent Attritor & bead mill Particle Size - 0.20-0.25 micron Hegman gauge
Skin Coat preparation PVC, plasticizer, stabilizer, additives, pigment Homogeneous mixture Viscosity – As per specified procedure Ford Cup
Middle coat preparation PVC, plasticizer, stabilizer, additives, pigment Homogeneous mixture Viscosity – As per specified procedure Ford Cup
Adhesive coat preparation PVC, plasticizer, stabilizer, additives Homogeneous mixture Viscosity – As per specified procedure Ford Cup

Example 3: Characteristics of the final product or the breathable composite sheet
[0041] The final product or the breathable composite sheet thus obtained showed specific physical properties and mechanical physical performance properties. Weight of the final product was found to be 700-850 g/m2 and gauge was found be 0.8-1.0 mm by using the IS 7016 test method. Air permeability of the final product was shown to be 8.61mm/sec by using ISO 9237 test method and water vapour permeability was found to be 0.28mg/cm2 hrs by using ISO 20344:2011, ISO 14268 test method. Table 3 below shows the physical properties of the final product. Mechanical physical performance properties of the final product includes breaking strength, elongation, tear strength, adhesive strength, abrasion, fogging (gravimetric), and accelerated weathering resistance. By using IS 7016 test method, mechanical physical performance properties of the final product or the nano-perforated composite sheet including breaking strength was found to be =200N (MD) and =190N (TD), elongation was found to be =32% (MD) and =108% (TD), tear strength was found to be =20N (MD) and =14N (TD), and adhesive strength was found to be =35N (MD) and =35N (TD). For the abrasion properties no gloss of colour change and no loss of coating was found when tested using IS 7016 method. Fogging (Gravimetric) was found to be ?1.5 mg upon testing with SAE J1756 method. For accelerated weathering resistance property no cracking, chalking, tackiness, loss of grain, wrinkling, blistering, or other undesirable effects (ratings =4 Gray scale) were found when tested using ISO 105-B06 (Condition 5) method.

TABLE 3: Physical properties of the final product
Properties Results Test Method
Weight 700-850 g/m2 IS 7016
Gauge 0.8-1.0 mm IS 7016
Air Permeability 8.61mm/sec ISO 9237
Water Vapour Permeability 0.28mg/cm2 hrs ISO 20344:2011
ISO 14268
[0042] In accordance with an embodiment of the present invention, the breathable composite sheet (1000) or nano-perforated composite sheet is capable to be used in areas and locations of high moisture and applications that have regular contact with water without compromising on the strength and durability of the nano-perforated composite sheet.

[0043] In accordance with an embodiment of the present invention, the method and the nano-perforated composite sheet or breathable composite sheet (1000) helps in replacing fabrics, and also usual perforated leatherette; wherein designers have more to play with aesthetics while the user gets the benefit of avoiding pass through of liquids and dust through the end product or the nano-perforated composite sheet.

[0044] In accordance with an embodiment of the present invention, the breathable composite sheet (1000) may be potentially used in the field of automotive industry, manufacturing industry, household appliances, fashion products, textile industry or the like. Further, the breathable composite sheet (1000) may have applications where air permeability is important. For example, the nano-perforated composite sheet or breathable composite sheet (1000) may be used in automotive upholstery including, but not limited to, seats with and without ventilation systems; or may be used in furnishing and upholstery for sweat free comfort. Further, nano-perforated composite sheet may have injection moulding and foam in place applications as nano-perforations help reduce wrinkles during assembly process as air or gasses of the process can pass through the composite sheet or the leatherette due to nano-perforations.

[0045] Apart from what is disclosed above, the present invention also includes some additional benefits and advantages. Few of the additional benefits are mentioned below:

• The present invention provides the breathable composite sheet which is aesthetically appealing wherein the perforations are such that the holes created are invisible to the naked eyes and hence do not interfere with the aesthetic appeal of the composite sheet.

• The nano-perforations in the composite sheet bring various benefits such as anti wick properties, as well as breathability. Further, dust particles cannot pass through such nano-perforations which prevents blockage of the nano-perforated composite sheet thus, ensuring proper functioning of the nano-perforated composite sheet.

• The nano-perforations present low water permeability as compared to normal perforated leatherette making the nano-perforated composite sheet waterproof or liquid proof.

• Additionally, the nano-perforations do not hamper the composite sheet properties and present moisture management, prevent rapid water absorption by the composite sheet, and thereby increases the strength and durability of the nano-perforated composite sheet without reducing the breathability of the composite sheet.

[0046] The foregoing descriptions of exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiment was chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions, substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.

CLAIMS:
We Claim:

1. A breathable composite sheet (1000), comprising:
a sequentially arranged layers of skin coat, foam coat, adhesive coat and fabric from bottom to top;
wherein said layers are collectively heated and perforated by micro needling to obtain a nano-perforated composite sheet having nano-perforations (200) of size ranging from 0.3 to 1 micron.

2. The breathable composite sheet (1000) as claimed in claim 1, wherein said composite sheet comprises at least 50% Polyvinyl chloride (PVC) with a ratio of plasticizer being at least 60% of PVC.

3. The breathable composite sheet (1000) as claimed in claim 1, wherein said layers of skin coat and foam coat are formed from a coating composition comprising
a mixture of polymer, plasticizer, stabilizer, pigments, and additives;
wherein said polymer is Polyvinyl chloride (PVC) and said plasticizer is Dioctyl terephthalate (DOTP);
wherein said pigments are selected from a group consisting of titanium dioxide, and red oxide (black oxide or yellow pigment);
wherein said additives are selected from a group consisting of Antimony Trioxide, Antimony Dihydrate, and Tinuvin-P.

4. The breathable composite sheet (1000) as claimed in claim 1, wherein said layer of adhesive coat is formed from a coating composition comprising
a mixture of polymer, plasticizer, stabilizer, and additives;
wherein said polymer is Polyvinyl chloride (PVC) and said plasticizer is Dioctyl terephthalate (DOTP);
wherein said additives are selected from a group consisting of Antimony Trioxide, Antimony Dihydrate, and Tinuvin-P.
5. The breathable composite sheet (1000) as claimed in claim 1, wherein said layers are collectively heated at a temperature of 160°C.

6. The breathable composite sheet (1000) as claimed in claim 1, wherein said fabric is a polyester spun fabric.

7. A method of preparing a breathable composite sheet (1000), comprising the steps of:
extruding a PVC based coating composition;
forming layers of skin coat, foam coat, adhesive coat and fabric from bottom to top by said coating composition;
heating said layers to obtain a composite sheet; and
perforating said composite sheet by micro needling to create nano-perforations (200) of size ranging from 0.3 to 1 micron.

8. The method as claimed in claim 7, wherein said step of heating is performed at a temperature of 160°C.

9. The method as claimed in claim 7, wherein said step of perforation by micro needling is performed by passing the composite sheet through a post processing machine having a die and a backing rubber support such that perforations are made between said rubber support and said composite sheet, thereby making nano-perforations (200) in the composite sheet.

10. The method as claimed in claim 7, wherein said micro needle has a diameter of 0.32 micron.

11. The method as claimed in claim 7, wherein said composite sheet comprises at least 50% PVC with a ratio of plasticizer being at least 60% of PVC.

12. The method as claimed in claim 7, wherein said layers of skin coat and foam coat are formed from a PVC based coating composition comprising
a mixture of PVC polymer, plasticizer, stabilizer, pigments, and additives;
wherein said plasticizer is Dioctyl terephthalate (DOTP);
wherein said pigments are selected from a group consisting of titanium dioxide, and red oxide (black oxide or yellow pigment);
wherein said additives are selected from a group consisting of Antimony Trioxide, Antimony Dihydrate, and Tinuvin-P.

13. The method as claimed in claim 7, wherein said layer of adhesive coat is formed from a PVC coating composition comprising
a mixture of PVC polymer, plasticizer, stabilizer, and additives;
wherein said plasticizer is Dioctyl terephthalate (DOTP);
wherein said additives are selected from a group consisting of Antimony Trioxide, Antimony Dihydrate, and Tinuvin-P.