Description:A COMPOSITE PANEL AND METHOD OF MANUFACTURING THEREOF
FIELD OF THE INVENTION
[001] The present invention relates to a composite panel used for interior / exterior applications such as wall panel, roofing sheets, shades, false ceiling tiles / planks, insulation, and other similar applications. having excellent rigidity. The composite panel has improved mechanical, heat reflecting, acoustic and thermal properties. The composite panel comprising of two polymer laminates of similar composition and a layer of post-consumer recycled polymers packaging or aluminium foils, woven or non-woven, and paper etc., sandwiched between them, is disclosed.
BACKGROUND OF THE INVENTION
[002] Composite panels consist of an insulating core layer sandwiched between two layers of polymer, usually metal and / or polymers. The outer layer of these panels is preferably made of Aluminium. These panels have many desirable characteristics, such as light weight, easy fabrication and installation, weather resistance, durability, and aesthetic appeal. However, the core of these panels is usually made of virgin polymers, which have a high environmental impact and are expensive and have Aluminium sheets of higher thicknesses.
[003] Further, plywood has been used for construction panels due to its availability in diverse sizes and thicknesses and ease of machining and joining for shaping and subsequently polishing or painting. But they are fire hazardous and do not have very good moisture resistance. Moreover, the input source for manufacturing is wood from trees, thus not sustainable.
[004] On the other hand, environmental pollution is becoming increasingly severe due to various waste polymers substrates such as industrial and post-consumer packaging waste, household waste polymers, single use polymers etc. However, the current situation is that the waste polymers are not properly recycled, and the available recycling resources are not cost-effective being highly energy consuming without giving valuable outcome.
[005] Recycled polymers have the primary advantage of lower cost and may require less energy in conversion using innovative methods. However, not all polymers can be recycled easily or safely, especially when the use is for food packaging, medical, pharma or other sensitive applications.
[006] One of the challenges of recycling polymers is dealing with multilayer packaging, which consists of different types of polymers, co-extruded or laminated together to provide better protection and functionality. These multilayer structures preferably comprise of paper, polyolefins Nylon, and aluminium foil or metalized, apart from other tie layers & barrier polymers. The process to separate and segregate these multilayered polymers is not possible or very difficult and often ends up in landfills or incinerators.
[007] Accordingly, there is need to use recycled polymers / multilayer packaging in non-food applications that require high quality and performance, such as flooring, roofing, panelling, furniture, dustbins, fencing, shades, under deck parts and covers of automobiles etc. These applications can offer the environmental and economic advantages of using recycled substrates, as well as the aesthetic and functional properties of polymers.
[008] The present invention proposes one of the alternative ways to use mono or multilayer mix packaging waste to convert it into composite panels, which can be used in the core layer of such polymer’s composite panels, the environmental impact can be reduced significantly, while maintaining the performance and quality of the panels.
OBJECT OF THE PRESENT INVENTION
[009] The object underlying the present invention is therefore to provide a novel polymers composite panel where the core layer is made up of shredded, cuttings or pulverized mono / multilayer packaging waste, with or without printing, aluminium foils / metallization, woven / non-woven substrates, and paper sandwiched between polymers layers, wherein the core layer essentially has content of polyolefin ranging from 30% to 95%.
[0010] Another object of the present invention is to provide recyclable, eco-friendly composite panels made from post-consumer or industrial polymers waste, which are durable, cost-effective, lightweight, and versatile.
[0011] Another object of the present invention is that such the composite panels can be used as roofing, wall panelling, tiles for false ceiling, to replace asbestos, clay roofing, metal, wooden and other polymer-based panels, or corrugated sheets or panels.
[0012] Another object of the present invention is that the composite panels can withstand extreme temperatures ranging from -20o C to +65o C and weather conditions such as rain, storm, snow, high wind speed, etc.
[0013] Another object of the present invention is composite panels to provide exceptional mechanical stability and insulation properties (both heat and noise), ensuring quieter and cooler enclosures.
[0014] Another object of the present invention is that the composite panels disclosed shall be able to withstand UV rays, scratches, inhibit microbial growth, and will not corrode. As a result, they can be in service for a long time if used carefully.
Another object of the present invention is to provide an improved composite panel and method of manufacturing a composite panel.
SUMMARY OF THE PRESENT INVENTION
[0015] The present invention relates to polymers composite panel made from recycled polymers waste that consists of a core layer between top laminate and bottom laminate. The core layer is composed of shredded, cuttings or pulverized mono / multilayer packaging waste, with or without printing, aluminium foils / metallization, woven / non-woven substrates, and paper sandwiched between top laminate and bottom laminate, irrespective of the type of the polymers the total content of polyolefins present in the core layer ranges from 30 % to 95 % by weight. The top laminate and bottom laminate are laminated with the surfaces of the core layer on both sides. The composite panels are novel and have various applications.
[0016] The core layer of the polymers composite panel of the present invention is produced by a process that involves shredded, cuttings or pulverized mono / multilayer packaging waste, with or without printing, aluminium foils / metallization, woven / non-woven substrates, and paper sandwiched between polymers layers, wherein the core layer essentially has content of polyolefin ranging from 30% to 95%. mixing them together and forming them into a core layer of desired thickness, size, and shape.
[0017] The core layer is then sandwiched between top laminate and bottom laminate having similar composition, which are laminated with shredded, cuttings or pulverized multilayer packaging waste, with or without aluminium foils / metallization, woven / non-woven substrates, and paper of the core by heat and pressure. One method of making core layer from waste of multilayer packaging is to be shredded, cuttings or pulverized mono / multilayer packaging waste, with or without printing, aluminium foils / metallization, woven / non-woven substrates, and paper and use it as it is, without any prior processing. This can be done by mechanical means, such as cutting, tearing, or grinding.
[0018] Another method of producing a core layer from waste of paper-polymer Aluminium foil-based packaging waste is to remove the paper pulp from the multilayer packaging by chemical means, such as alkaline hydrolysis or enzymatic digestion. The paper pulp can be recovered and used for paper production, while the residue containing aluminium, polyolefin such as polyethylene, ink, and traces of tie layers can be used in the manufacturing of core layer. A waste of other single or multilayer polymeric films or laminates can also be added to make core layer.
[0019] The top laminate and bottom laminate can be made of any suitable polymers either individually or in combinations. The composite panels of the present invention have several advantages over conventional substrates. They are environmentally friendly, as they utilize recycled polymer that would otherwise end up in landfills or incineration. They are also durable, lightweight, and resistant to water, fire, and insects. They can be used for various applications, such as roofing, flooring, wall panels, furniture, packaging, or heat and sound insulation.
[0020] The composite panel of the present invention has advantages such as strength, offer heat and sound insulation, reflect sun light when used in outdoor applications, reducing heat load inside the enclosure thus resulting in significant energy savings, low environmental impact due to use of recycled polymers and itself being recyclable, offers a seamless roofing or panelling surface with long service life.
[0021] The present invention also discloses a method of making profiled composite panel such as corrugated or curved panel, which has top laminate and bottom laminate of the similar structures and a core layer of shredded, cuttings or pulverized mono / multilayer packaging waste, with or without printing, aluminium foils / metallization, woven / non-woven substrates, and paper sandwiched between top laminate and bottom laminate (polymers layers), wherein the core layer essentially has content of polyolefin ranging from 30% to 95%.
BRIEF DESCRIPTION OF THE DRAWING
[0022] The advantages and features of the present disclosure shall be better understood with reference to the following detailed description taken in conjunction with the accompanying drawing, wherein like elements are identified with like symbols and in which:
[0023] FIG. 1 illustrates a Composite Panel, in accordance with an exemplary embodiment of the present disclosure.
[0024] FIG. 2 illustrates a Composite Panel, in accordance with another embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0025] For a thorough understanding of the present disclosure, reference is to be made to the following detailed description in connection with the above-mentioned drawings. Although the present disclosure is described in connection with exemplary embodiments, the present disclosure is not intended to be limited to the specific forms set forth 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 present disclosure. Further, it will nevertheless be understood that no limitation in the scope of the disclosure is thereby intended, such alterations and further modifications in the figures and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates. 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. Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the disclosure. Furthermore, the appearances of such phrase at various places herein are not necessarily all referring to the same embodiment. The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.
[0026] As used herein, the term "roofing" means the provision of a plain or corrugated or curved roof of a building or enclosure, and without limitation, such a panel might take the form of shingles, tiles, wall panels, planks, boards, mouldings, or sheets and can be used for false ceilings.
[0027] As used herein, the terms "cladding" and / or "siding" mean the provision of a protective and or aesthetic covering on a side or other surface of a building. Without limitation, such a protective covering might take the form of shingles, tiles, panels, planks, boards, composite panels, mouldings, or sheets.
[0028] As used herein, the term “Multilayered Packaging” means any substrate used or to be used for packaging and having at least one layer of polymer as the main constituent either alone or in combination with one or more layers of paper, paper board, polymer, metallization, adhesive and aluminium foil. These layers can be laminated or co-extruded together to form the substrate.
[0029] As used herein, the term “Type-1 waste” means the post use or rejected polymeric packaging waste recovered after recycling of multilayer packaging to separate out pulp of paper or paper board using delamination or enzymatic dissolution or any other chemical recovery process or combination thereof. The residue obtained may contain polymeric layers, metal foil or metallized layer, adhesive or tie layer residues. Sometimes, metal is also recovered from metal foil or metallized layer in the packaging substrate leaving polymeric residue. Further, this term also contemplates polymeric residue recovered after any chemical or enzymatic or combination of both as recovery process performed on multilayered packaging. This type-1 waste may include industrial waste.
[0030] As used herein, the term “Type-2 waste” means shredded, cuttings or pulverized mono or multilayer packaging waste, with or without printing, aluminium foils, metallization, woven, non-woven substrates, paper, or paper board, sandwiched between polymers layers. This type-2 waste may include industrial waste.
[0031] As used herein, the term “Polymeric Waste” means any polymeric packaging waste discarded after use or after their intended use is over.
[0032] As used herein and to explain the preferred embodiment of the present invention, reference numerals in bracket separated by the commas (_, _) are used to refer the respective layers.
[0033] FIG 1 shows a cross sectional view of a composite panel structure (100), in accordance with the first aspect of the present disclosure. The present invention relates to the structure of composite panel (100) along with a method of creating a novel composite panel (100) having core layer produced from recycled polymers preferably of multilayer packaging grade. The composite panel (100) broadly has two layers i.e., top laminate (L1), and bottom laminate (L2) of similar structure and a core layer (122) comprised of Type-1 waste and Type-2 waste. The core layer (122) is comprised either of or in combination of Type-1 or Type-2 waste, wherein the core layer essentially has content of polyolefins ranging from 30% to 95% that fills the entire gap between them. The top laminate (L1), and bottom laminate (L2) or outer layers (L1, L2) correspond to the thin layers of polymers present on upper and lower side of the core layer (122), respectively.
[0034] According to the embodiments of the present invention, the top outer layer (110) and the bottom outer layer (210) are provided with metallization (114, 214) facing the core layer (122). The metallization (114, 214) on the top outer layer (110) and the bottom outer layer (210) can be any one of metalized layer can be of Aluminium, Aluminium Oxide, zinc sulphide, Silicon Oxide or one or more of Silver, Gold, Copper or Chrome or silicon monoxide, silicon dioxide or magnesium fluoride or titanium dioxide, tin tungsten oxide and indium tin oxide or any other suitable metal.
[0035] According to the embodiments of the present invention at least one of top outer layer (110) and bottom outer layer (210) is metallized however both the layers (110, 210) can also be metallized. In outdoor applications the metallized layer of the composite panel is installed facing the open atmosphere so that it reflects sunlight and reduces heat absorption.
[0036] The top outer layer (110) and the bottom outer layer (210) are preferably polyethylene, Polyethylene Terephthalate (PET), or Biaxially Oriented Polypropylene (BOPP). In another embodiment PET layers can be biaxially oriented.
[0037] In another embodiment either both or any of the top core side surface (110B) of the top outer layer (110) and / or the bottom core side surface (210B) of the bottom outer layer (210) optionally includes at least one of hologram, Fresnel lens and any other optical pattern also known as Optical Variable Device (OVD) embossing (112, 212). The OVD embossing may be applied before metallization (114, 214) or after metallization.
[0038] The top outer layer (110) and/or the bottom outer layer (210) may have reverse printed content (116, 216) on their core side surfaces (110B, 210B), either before or after metallization (114, 214). The printed content (116, 216) can be any one or combination of text, images, or patterns, printed with ink or hot foil transferred text. The printing content (116, 216) can be registered or unregistered with either any of or combination of holography, Fresnel lens, any other optical pattern, or printed text. Alternatively, the printing can be done on the outer surfaces (110A, 210A) of the layers.
[0039] The top outer layer (110) with metallization (114) and bottom outer layer (210) optionally with metallization (214), with or without OVD (112, 212) and printed content (116, 216), are laminated with adhesive (118, 218) with the top inner layer (120) and the bottom inner layer (220), respectively, to form two laminates (L1, L2). The top inner layer (120) of top laminate (L1) and bottom inner layer (220) of the bottom laminate (L2) laminates with the top surface (122A) and bottom surface (122B) of the core layer (122), respectively.
[0040] In one of the embodiments the top laminate (L1) and bottom laminate (L2) do not have metallization (114, 116), OVD (112, 212), and printed content (116, 216). The top laminate (L1) and bottom laminate (L2) are then laminated with the core layer (122) by heat and pressure, to complete the structure of composite panel (100).
[0041] The core layer (122) is the thickest layer of the composite panel (100) with two sides 122A and 122B.
[0042] The composite panel (100, 200) of the present invention is recyclable.
[0043] Further, the top inner layer (120) and the bottom inner layer (220) can be of any polyolefin such as polyethylene, low density polyethylene, high density polyethylene, linear low-density polyethylene, and polypropylene or of any co-polymer of olefins which are heat sealable such as Ethylene Vinyl Acetate (EVA) and combination thereof.
[0044] Figure 2 illustrates a modified composite panel (200) in accordance with another exemplary embodiment. This embodiment shares the same features as the composite panel (100), except that it does not require two adhesive layers (118, 218) to bond the top outer layer (110) and the bottom outer layer (210) with top inner layer (120) of top laminate (L1) and bottom inner layer (220) of the bottom laminate (L2) respectively. A hot extruded film is dropped over the top outer surface (110B) of the top outer layer (110) or the bottom outer surface (210B) of the bottom outer layer (210) and pressed between rollers in line with the top inner layer (120) and the bottom inner layer (220) of L1 and L2, respectively. In this embodiment the top inner layer (120) and the bottom inner layer (210) are configured by extrusion lamination.
[0045] In one embodiment, the composite panel (100, 200) comprises a plurality of formed or corrugated surfaces configured along the length or width of the composite panel (100, 200). The composite panel (100) can have different shapes and patterns, such as corrugated, folded, bent, embossed, or curved, depending on the design of the forming die. The composite panel (100, 200) can be symmetrical or asymmetrical in shape and thickness.
[0046] The composite panels (100, 200) are water resistant so that they do not swell when remain in water for prolonged periods. In addition, the panels are resistant to various chemicals and detergents and therefore can be used even in industrial, recreational or garage environments. The water absorption test and swelling thickness is conducted in accordance with the ASTM D570.
[0047] In another embodiment, the core layer (122) comprises about 30% to about 95% w/w waste multilayer polymers.
[0048] The composite panel (100) is evaluated for its stability, mechanical properties, nail and screw resistance and withdrawal performance, and weathering resistance to assess its compatibilities for various applications in view of various innovative features described above. The present invention has been evaluated according to various ASTM standards, which are specified in the following table. These standards are widely accepted and recognized in the industry and provide reliable and consistent results however some standards have been adopted for composite panel considering the application although the scope of the standard does not include composite panel disclosed in this invention. The present invention has demonstrated superior performance and quality compared to the prior art under these testing conditions for the applications considered for the composite panel of this invention.
S.
No. Test Methods Results Desirable Range
Dimensional Stability
1. Density ASTM D 792-20 642 kg./m3 at 27o C 550~700 kg./m3
2. Water Absorption ASTM D 570-22 2 % ?3%
3. Thickness Swelling ASTM D 570-22 1 % Max.10% for 24-hour
water absorption test

Mechanical Properties
4. Tensile Properties ASTM D 638-22 7MPa 5 to 15 MPa
5. Flexural Modulus ASTM D 790-17 844Mpa 600~950 MPa
(450~600Mpa is considered as low modulus)
6. Flexural Strength ASTM D 790-17 11 MPa 8~16 MPa
7. Izod Impact Strength (Notched) ASTM D 256-04 80 J/m 55~95J/m
(15~22 J/m considered as brittle)

Nail and Screw Withdrawal Tests
8. Screw Withdrawal Strength ASTM D1037-12 475N 419~721 N
Parallel to plane
9. Nail Withdrawal Strength ASTM D1037-12 256N 225~360 N
Parallel to plant

Weathering Test
10 Neutral Salt Spray Test (For 500 Hours) ASTM B 117-19 No Corrosion Observed
[0049] In the present embodiment, the core layer (122) comprises about 30% to about 95% w/w of polymers. The polymers in the core layer (122) comprises one or more of the following polymers: Bi-axially oriented polypropylene, cast polypropylene, oriented polypropylene, extruded polypropylene, polyethylene, polytetrafluoroethylene, polyvinylchloride, low density polyethylene, low linear density poly ethylene, high molecular weight polyethylene, high-density polyethylene, Mylar, Nylon, polycarbonate, expanded polyethylene, Acrylic, acrylonitrile butadiene styrene and ethylene vinyl acetate or any other polymer or their combinations known in the art.
[0050] The composite panel (100) comprising outer laminates (L1, L2) and core layer (122) may contain various additives such as UV stabilizers, infrared stabilizing agents, antioxidants, fire retardants. An important aspect of the present invention is that through the use of such inhibitors, stabilizing agents, and antioxidants, etc. the performance of such composite panels further enhances, particularly in outdoor applications.
[0051] The core layer (122) comprises 0% to 30% w/w of particles / shreds of aluminium foil / metallization.
[0052] The core layer (122) comprises 0% to 10% w/w of paper.
[0053] The length of composite panel (100) ranges from 1m to 3m and its width ranges from 0.5m to 2.5m. The thickness of the composite panel (100) ranges from 5mm to 50mm. The composite panel (100) may be easily installed as a roof, cladding, wall panels, tiles, or false ceiling, and can readily be adhered thereto as well as to one another by utilizing an adhesive or mechanical fasteners. The adhering feature of this system provides a complete and uniform water-tight surface of high durability and strength which each composite panel (100) connected to each other such as being abutted thereto, overlapped therewith, etc. Such composite panel (100) can be usefully employed, i.e., for full-surface glued floor panels or wall panels, wall cover panels or ceiling panels / false ceiling tiles, with or without mechanical fastening systems. The composite panel (100) outer layers are hydrophobic and will not degrade or swell in the presence of water. Further, they do not contain hazardous chemicals requiring special handling during installation and subsequent use.
[0054] In another embodiment, the top inner layer (120) and the bottom inner layer (220) further comprises one or more of the following :
a. a) flame retardants including but not limited to magnesium hydroxide, aluminium trihydrate, aluminium hydroxide.
b. e) UV stabilizers including but not limited to UV light stabilizers such as hindered amine light stabilizers (HALS, o-hydroxyphenylbenzotriazoles, 2-(2’-hydroxy-3’-tert-butyl-5’- methyl phenyl)-5-chlorobenzotriazole (Tinuvin 326TM), titanium dioxide (TiO2), zinc oxide (ZnO) and silicon dioxide (SiO2).
[0055] In the preferred embodiment of outer laminates (L1, L2), the top outer layer (110) is always metallized, and the bottom outer layer (220) may or may not be metallized PET polyolefin laminate. The outer laminates (L1, L2) comprise of three layers, top layer, middle layer, and inner layer. The top layer is of metallized PET (110, 210), the middle layer is of adhesive, (118, 218) and inner layer is of polyolefins (120, 220).
[0056] The top outer layer (110) and the bottom outer layer (210) have thickness ranging from 8 micron to 30 micron.
[0057] The middle layer of Outer laminates (L1, L2) are adhesive layers (118, 218) selected from the group consisting of based on any or combination of polyurethanes, ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA), ethylene acrylic acid (EAA), ethylene methacrylic acid (EMAA), and ethylene-grafted-maleic anhydride.
[0058] The top inner layer (120) and the bottom inner layer (220) of the outer laminates (L1, L2) comprise of polyolefin preferably polyethylene, low density polyethylene, high density polyethylene, linear low-density polyethylene, and polypropylene or of any co-polymer of olefins which are heat sealable such as Ethylene Vinyl Acetate (EVA) and combination thereof of any grade & type. The thickness of the top inner layer (120) /or the bottom inner layer (220) ranges from 15microns to 200 microns.
[0059] An essential aspect of the top outer layer (110) and the bottom outer layer (210) is that it reflects radiant energy and heat, that is, infrared light, visible light, and ultraviolet light. The outer layer is weather resistant to extreme temperatures and rains making it suitable for outdoor use exposed to external environment.
[0060] The top inner layer (120) and the bottom inner layer (220) consist of polyolefin, which has adhesive properties and can bond with the core layer (122) under heat and pressure. Therefore, the top inner layer (120) and the bottom inner layer (220) face the top surface (122A) and bottom surface (122B) of the core layer (122), respectively, in the composite panel (100, 200).
[0061] In the preferred embodiment the top inner layer (120) and the bottom inner layer (220) can be activated or pretreated using auxiliary methods known to the person skilled in the art, such as, for example, Corona treatment, flame treatment, laser pretreatment, ionic etching, sputtering or plasma pretreatment (low-pressure plasma/atmospheric-pressure plasma), in order to enable a better adhesion with adhesive to laminate with top outer surface (110B) of the top outer layer (110) and / or the bottom outer surface (210B) of the bottom outer layer (210) with the top layer of polyolefin (120) and the bottom layer of polyolefin (220).
[0062] In the preferred embodiment the composite panel (100, 200) comprises the top layer (110) and the bottom outer layer (210) with metallization’s (114, 116) on at least any of the top layer (110) and the bottom outer layer, that reflects heat and light, and the top layer of polyolefin (120) and the bottom layer of polyolefin (220) that provide flexibility and heat-sealing properties. The two outer layers (110, 210) are laminated with inner layers (120, 220) to form laminates L1 and L2 using adhesive layers (118 and 218) that can be selected from polyurethanes, ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA), ethylene acrylic acid (EAA), ethylene methacrylic acid (EMAA), and ethylene-grafted-maleic anhydride or a combination thereof.
[0063] The method of formation of Type-1 waste in core layer (122) uses residual materials after separating paper pulp from the packaging waste by chemical or enzymatic treatment or a combination of both. The residual materials may include polymers, metal traces of metallization or foils, ink, coating and adhesive.
[0064] A method (300)of manufacturing a composite panel (100) comprising a core layer (122) of either or both Type-1, and Type-2 waste, sandwiched between outer layers (L1, L2) on both sides of the core layer (122) includes the following steps:
a. Placing (310)the outer layer (L2 or L1) in the forming dye (320), keeping polyolefin layer (220) upwards.
b. Multilayered Packaging waste Type-1 or Multilayered Packaging waste Type-2 or mix of both types of waste in any combination is filled and spread (330) in a uniform layer above the polyolefin layer (220) of the outer layer (L2 or L1), in the forming die.
c. Optionally vibrating (322) the forming die to spread the layer of waste uniformly.
d. The outer layer (L1 or L2) is placed (340) over the waste for core layer in the forming die, with its polyolefin side facing downwards.
e. The forming die is then positioned under a high-pressure press with pressing punch pressing the uniform layer of waste Type-1 or Type-2 or combination of both the types of waste in any combination.
f. A pressure (350) typically in the range of 8 kg./cm2 ~ 20 kg./cm2 is applied for 10 to 30 mins, depending upon thickness of the composite panel to be made and the type of substrates used for core layer (122). Either the forming die or pressing punch or both are heated (360) in the range of 100oC ~ 200oC. The pressure (350) or heat (360) may be applied simultaneously or in any order to the forming die (320).
g. The forming die and / or pressing punch may be heated by using coil heaters, rod heaters, flat heaters, infrared heaters, induction heaters or by hot oil circulation in closed channels.
h. The polyolefin layers of L1 and L2 get laminated with the top surface (122A) and bottom surface (122B) of the core layer (122), respectively, under pressure and heat together to form a bond between them and form a composite panel (100, 200). The forming dies can be stacked one over the other after filling with L1, TYPE-1 or TYPE-2 and L2 substrates and then heated and pressed all together for set duration. The pressure in the press is released and forming dies are taken out and cooled at room temperature or in the cold room to pull out the formed panels.
i. The panels coming out (370) of the forming dies are hot and soft and need gentle handling to place and attain rigidity. The composite panel (100, 200) is cooled and stablized (380) to avoid warpage. The hot profiled panels may be required to be placed on profiled surface matching with the profile on the panels.
j. The uneven edges and corners of the panels may be trimmed or sheared (390) in hot condition or after cooling to get a clean panel in required sizes. The trimming or shearing may be performed manually using suitable cutting means or by using automatic machines like high-speed flatbed milling, sawing machines or laser or water jet cutting machines. The method provides a composite panel (100, 200) with improved strength and durability.
[0065] In one of the embodiment’s forming die (330) is profiled, so that composite panel with desired corrugation or shape is obtained.
[0066] In another embodiment the technique for creating composite panels may entail the initial step of forming the panel in a flat forming dye (320A) and the preformed composite panel is taken out (370) of the die and further placed in a profiled die, followed by the application of heat and pressure to get the desired corrugation / shape in the composite panel (100, 200). However, if the flat panel formed is cooled and stored then is corrugation / profiled panel is to be made then the flat panel is preheated in an oven or hot room up to a temperature between 80oC ~ 120oC and then place in the profiled forming die (320B) to press, hold and taken out for cooling to obtain corrugated / profiles panels.
[0067] From the foregoing, it should be apparent that the present invention provides an inexpensive, strong, and durable composite panel (100, 200) having a wide variety of applications such for outdoor roofing, walls, false ceiling tiles, partitions, and other building or other engineering elements. The composite panel (100, 200) disclosed can withstand high unit loadings in compression and bending and is dimensionally stable under a wide range of temperature, humidity, and other weather conditions. The improved sound absorption of the composite panel (100, 200) may be provided on one or both sides of the structure with or without acoustic insulation. , Claims:We claim,
1. A composite panel (100, 200) comprising:
a) a top outer laminate (L1) having a top outer layer (110) with a thickness ranging from 8 microns to 30 microns, and a top inner layer (120) of polyolefin of thickness ranging from 15 microns to 200 microns;
b) a core layer (122) comprising either or both of waste Type-1, and waste Type-2 in any combination consisting of polyolefins ranging from 30% to 95% by weight; and
c) a top bottom laminate (L2) having a bottom inner layer (220) of polyolefin of thickness ranging from 15 microns to 200 microns, to provide a structure to the composite panel (100, 200).
2. The composite panel (100) as claimed in claim 1, wherein the outer laminate (L1, L2) further comprises of a top middle layer (118) and a bottom middle layer (218) of adhesive.
3. The composite panel (200) as claimed in claim 1, wherein the top inner layer (120) and the bottom inner layer (220) are configured by extrusion lamination.
4. The composite panel (100, 200) as claimed in claim 1, wherein at least any one or both of the top outer layer (110) and bottom outer layer (210) comprise a metallized layer (114, 214).
5. The composite panel (100, 200) as claimed in claim 1, wherein the total thickness of the composite panel is ranging from 5 mm to 50 mm.
6. The composite panel (100, 200) as claimed in claim 1, wherein the length of the composite panel is ranging from 1 meter to 3 meter and the width of the composite panel is ranging from 0.5 meter to 2.5 meter.
7. The composite panel (100, 200) as claimed in claim 1, wherein the top outer layer (110) and bottom outer layer (210) can be any of polyethylene, polyethylene terephthalate, polypropylene, biaxially oriented polypropylene, biaxially oriented polyethylene terephthalate.
8. The composite panel (100, 200) as claimed in claim 1, wherein a suitable additive or additives are added in the range of 0.1% to 1%, in any or both of the top outer layer (110) or bottom outer layer (210) for protection from UV radiation.
9. The composite panel (100, 200) as claimed in claim 8, wherein the suitable additive for UV protection can be any or combination of amine light stabilizers (HALS), O-Hydroxyphenyl benzotriazoles, Carbon Black, Titanium Dioxide, Tinuvin 326TM, Zinc Oxide, Silicon Dioxide, Acrylic Copolymers, 2-Hydroxy-Benzophenone, 2-Hydroxy-Benzotriazole Derivatives and Hydroxy-Phenyl Triazine derivatives.
10. The composite panel (100, 200) as claimed in claim 1, wherein printing, reverse printing, holography, barcodes, latent images, Fresnel lens and other optical security features are provided in any or both of the top outer layer (110) or the bottom outer layer (210).
11. The composite panel (100, 200) as claimed in claim 1, wherein the core layer (122) is further comprised of 0% to 30% w/w particles / shreds of aluminium foil or metallization, and 0% to 10% w/w paper.
12. The composite panel (100, 200) as claimed in claim 1, wherein the core layer (122) of the waste type-1 and waste type-2 are in the form of shredded, cuttings or pulverized, mono / multilayer packaging waste, with or without printing, aluminium foils / metallization, woven / non-woven substrates, and paper sandwiched between polymer layers, including residual matters remaining after de-pulping and chemical and or enzymatic treatments.
13. The composite panel (100, 200) as claimed in claim 1, wherein the shape of the composite panel can be any of flat, corrugated, eclipsed, a crescent, or any other profiled shape.
14. The composite panel (100, 200) as claimed in claim 1, wherein the flame-retardant additives can be added to the top inner layer (120), and the bottom inner layer (220), including but not limited to magnesium hydroxide, aluminium trihydrate, aluminium hydroxide.
15. The composite panel (100,) as claimed in claim 1, wherein the adhesive layers (118, 218) are selected from the group consisting of based on any or combination of polyurethanes, ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA), ethylene acrylic acid (EAA), ethylene methacrylic acid (EMAA), and ethylene-grafted-maleic anhydride.
16. The composite panel (100, 200) as claimed in claim 1, wherein the composite panel (100, 200) is used in roofing, cladding, false ceiling, wall panels, tiles, wood substitutes, or any other similar applications.
17. The composite panel (100, 200) as claimed in claim 1, wherein the top outer layer (110), the bottom outer layer (210), the top inner layer (120), and the bottom inner layer (220) can be any one or combinations of single or multilayer polymeric films, laminate, and fibrous substrate.
18. The composite panel (100) as claimed in claim 1, wherein any one or both the top inner layer (120) and the bottom inner layer (220) are subjected to a pre-treatment method selected from the group consisting of corona treatment, flame treatment, laser pretreatment, ionic etching, sputtering, or plasma pretreatment to enhance adhesion.
19. A method (300) for forming a composite panel (100, 200) comprising the steps of:
a. putting (310) an outer laminate ( L1 or L2) on a frame inside a hydraulic forming dye with polyolefin side (120, 220) facing upwards;
b. spreading (330) a uniform layer of either or both of Type-2, and Type-1 waste in any combinations over the polyolefin side (120, 220) of outer laminate ( L1 or L2);
c. putting (340) the other outer laminate (L1 or L2) with polyolefin side (120, 220) on top of the Type 1 or Type -2 waste;
d. applying hydraulic pressure (350) to the frame, with the pressure ranging from 8kg/cm2 to 20kg/cm2;
e. heating (360) the hydraulic chamber to a temperature between 120 degrees Celsius and 180 degrees Celsius;
f. keeping the pressure (350) on for 15 to 30 minutes and taking out (370) the panel (100, 200);
g. cooling and stabilizing (380) the obtained panel optionally by cold pressing to avoid warpage; and
h. cutting and / or trimming (390) the composite panel (100, 200) to the required size.
20. The method as claimed in claim 19, wherein the forming die can be a flat (320A) or a corrugated / profiled (320B).
21. The method as claimed in claim 19, wherein the flat composite panel (100, 200) formed in a flat forming die (320A) can be further shaped into a profiled panel by preheating and pressing in a profiled forming die (320B).
Dated this 3rd day of January 2024.
-Digitally Signed :: Filed via e-Filing-
Gupta, Sandeep [IN/PA-3900]
AGENT FOR THE APPLICANT
To,
The Controller of Patents
The Patent Office,
at Delhi/Mumbai/Kolkata/Chennai