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BR-102024017739-A2 - OPTIMIZATION OF A MULTILAYER SHIELDING SYSTEM MADE OF EPOXY MATRIX COMPOSITE WITH SODIUM HYDROXIDE-MERCERIZED CATTRAY FIBER (TYPHA LATIFOLIA LINN).

BR102024017739A2BR 102024017739 A2BR102024017739 A2BR 102024017739A2BR-102024017739-A2

Abstract

The present invention features optimized thickness of the first layer and consequently reduces the weight of the multilayer armor system. The use of multilayer armor systems using polymer matrix composite materials reinforced with natural fibers has been studied as a potential candidate to replace those systems that employ synthetic fibers in their structure, such as aramid fiber. However, when considering other materials, it is necessary that the multilayer armor system with natural fiber composites exhibits a reduction in system weight. The system is composed of alumina ceramic as the first layer and an epoxy matrix composite reinforced with cattail fiber (Typha latifolia Linn) mercerized with sodium hydroxide as the second layer. The thickness of the ceramic layer varies from 10 to 7 mm. Its characteristics make it both resistant and economically advantageous for use in multilayer ballistic armor aimed at protection against high-impact rifle fire (7.62 mm caliber). The reduction in thickness yields results below those predicted by standards, even with a 7 mm first layer, and also a reduction in cost and weight. The present invention further describes relevant technical details for the production of the composite, including the composition range as well as the temperature and pressure conditions suitable for its ballistic performance.

Inventors

  • SERGIO NEVES MONTEIRO
  • ARTUR CAMPOSO PEREIRA
  • DOUGLAS SANTOS SILVA

Assignees

  • ARTUR CAMPOSO PEREIRA

Dates

Publication Date
20260310
Application Date
20240828

Claims (13)

  1. 1. Composite material characterized by a thermoset polymer reinforced with natural fiber.
  2. 2. The composite material of claim 1 is, in engineering terms, characterized as a composite due to having good adhesion between the dispersed phase, which is a natural fiber, and the polymeric matrix as the continuous phase.
  3. 3. The composite indicated in claim 2 will be characterized by a process of epoxy polymer matrix incorporating 30% by volume of cattail fiber (Typha latifolia Linn) mercerized with sodium hydroxide.
  4. 4. A manufacturing process characterized by the preparation of the composite described in claim 3 comprises the following steps: J Placing the cattail fiber (Typha latifolia Linn) mercerized with sodium hydroxide, corresponding to the desired proportion of 30% by volume, inside a suitable metal mold; J Adding still-fluid epoxy resin and sealing the mold.
  5. 5. The processing details of claim 4 are characterized by: J Rectangular metal mold with ballistic plate dimensions for use in personal vest or military vehicle; J Applying a pressure of 5 MPa at room temperature for a period of 5 hours to the capped mold, already filled with fiber and epoxy resin.
  6. 6. The process described in claims 3 to 5 allows the manufacture of plates with a thickness of up to 50 mm and lateral dimensions of up to 300 mm in carbon steel molds specified for this purpose.
  7. 7. The process described in claim 5 consists of demolding the plate with the aid of snap-fit screws, facilitated by the use of silicone grease previously applied to the inner surface of the mold.
  8. 8. The composite plate characterized by cattail fiber (Typha latifolia Linn) mercerized with sodium hydroxide reinforcing an epoxy matrix is suitable for use as a layer in ballistic armor aimed at protection against rifle fire with 7.62 mm or 5.56 mm caliber ammunition.
  9. 9. The ceramic material characterized by thicknesses of 7, 8, 9 and 10 mm comprising the following steps: J Use alumina (AhO3) doped with niobium (Nb2O5) in a proportion of 4% by mass with hexagonal geometry; J The alumina, niobium and polyethylene glycol powders, in liquid phase, are weighed and placed in an alumina ball mill for 12h; J Leave for 48h in an oven at 80°C for drying.
  10. 10. A manufacturing process characterized by a ceramic preparation described in claim 9 comprises the following steps: J Maceration and sieving to obtain the powder; J Pressing under a pressure of 30 MPa; J Green bodies are taken to the furnace to be sintered.
  11. 11. Multilayer armor, characterized by a composite plate of the present invention being bonded with polyurethane adhesive to a ceramic front layer, responsible for eroding the projectile and attenuating its impact.
  12. 12. Composite in a multilayer ballistic system characterized by the function of capturing ceramic and projectile fragments resulting from frontal impact.
  13. 13. Reducing the thickness of ceramic material is characterized by a decrease in cost and weight.

Description

Field of Invention [001] The present invention describes optimization of the thickness of the first layer and consequently reduction of the weight of the multilayer armor system. The system is composed of alumina ceramic as the first layer and an epoxy matrix composite reinforced with cattail fiber (Typha latifolia Linn) mercerized with sodium hydroxide as the second layer. This composite has characteristics suitable for application in multilayer ballistic armor aimed at protection against rifle fire with high-impact ammunition. The thickness reduction presents results below those foreseen in the standard even with a 7 mm first layer, and also a reduction in cost and weight. The present invention also discloses the process for manufacturing the material. Background of the Invention [002] Epoxy matrix composite materials reinforced with fibers or natural fabrics, produced from these fibers, have been used since the mid-20th century in industrial sectors such as automotive and construction. However, there is no record of their use in ballistic protection armor. [003] In ballistic protection used in personal vests and military vehicles, in addition to metallic and ceramic materials, polymeric compounds reinforced with synthetic fibers or fabrics are also used. [004] In isolation, polymer composite materials reinforced with natural fibers or fabrics do not have satisfactory ballistic performance. However, as an intermediate part of a multilayer system, they offer performance comparable to synthetic materials and at a much lower cost. [005] Patent document PI 8800573-A (Brazil, 1989) describes a “Rigid composite of polyester, phenolic or polyamide resin matrix reinforced with continuous p-aramid filaments coated with about 0.2 to 5% by weight of a solid adhesion modifier, with significantly improved ballistic performance, lighter weight, and reduced area density for a given level of ballistic performance”, however it does not deal with natural fiber or fabric, only polyamide which is synthetic and expensive. [006] Document WO2010/091476-A1 (USA, 2010) describes a “Ballistic fabric composed of 65 to 80% polyamide fibers interwoven with 20 to 35% animal or cotton fibers. The preferred animal fiber is wool and the preferred blend is 25% wool with 75% polyaramid fibers. The preferred polyaramid is Kevlar.” Unlike the present invention, only ¼ of the natural fibers, animal or cotton, are blended with ¾ synthetic fibers. [007] Document JP5877431-132 (Japan, 2011) describes a “Fiber-reinforced composite material comprising a corrugated composite fiber yarn 1 formed by point-wound wrapping of a thermoplastic synthetic fiber yarn 5 around a bundle of carbon fiber 3 and/or a natural fiber yarn 4 with these yarns subjected to varying tension”. However, the composite only uses synthetic, thermoplastic, or carbon fibers. [008] Document WO2012/093167-A1 (France, 2012) describes an “Injectable composite material, including: (a) 28 to 95% by weight of a polypropylene/polyethylene copolymer; (b) 0 to 10% by weight of a flow enhancer; (c) 1 to 20% by weight of an impact modifier; (d) 1 to 20% of a compatibilizing agent; and (e) 3 to 70% by weight of natural fibers, in which the polypropylene/polyethylene copolymer forms a matrix. The invention also refers to a method for preparing said composite material, as well as a method for using it in the manufacture of parts by injection or overmolding.” Although it deals with a natural fiber reinforced composite, there is no indication for its use in ballistic armor. [009] Document CN207904438-V (Chile, 2018) describes “A resistant and durable yarn based on a mixture of natural jute and PET, which consists of a composite comprising a jute fiber layer, a polypropylene fiber layer, a PET fiber layer, a polyurethane fiber layer, an adhesive layer and a nylon fiber layer”. Although it contains jute fiber, there is no indication that the yarn can be used for shielding. [0010] None of the patent documents mentioned above resemble the present invention as they do not specifically deal with a composite reinforced exclusively with natural cattail fiber (Typha latifolia Linn) mercerized with sodium hydroxide for use in multilayer ballistic shielding. Summary of the Invention [0011] The overall objective of the invention is to optimize the thickness of the first layer and consequently reduce the weight of the multilayer shielding system. [0012] The specific objective is to manufacture ceramic plates of varying thicknesses: 7, 8, 9 and 10 mm. [0013] The manufacture of ceramics involves maceration and sieving to obtain the powder. Pressing under a pressure of 30 MPa generates green bodies that are taken to the furnace to be sintered. [0014] The ultimate goal of this invention is to reduce the thickness of the ceramic material, characterized by a decrease in cost and weight. In addition, composite material plates are used as part of a multi-layered armor system for the protection of personnel and milit