CAMPOSO PEREIRA ARTUR (BR)
| WO2019182362A1 | 2019-09-26 |
| US10751983B1 | 2020-08-25 | |||
| US20150253114A1 | 2015-09-10 | |||
| US6389594B1 | 2002-05-21 | |||
| US7875563B2 | 2011-01-25 | |||
| CN106515110A | 2017-03-22 | |||
| CN104848748A | 2015-08-19 | |||
| BRPI0602097A | 2008-01-15 |
HONGBING FANG ET AL.: "A numerical and experimental study of woven fabric material under ballistic impacts", ADVANCES IN ENGINEERING SOFTWARE, vol. 96, 2016, pages 14 - 28, XP029495830, Retrieved from the Internet
| 6 CLAIMS Composite material characterized by thermosetting polymer reinforced with natural fiber. The composite material of claim 1 is, in engineering terms, characterized by a composite in which there is a good adhesion between, a natural fiber, as dispersed phase, and the polymeric matrix, as the composite continuous phase. The composite indicated in claim 2 will be characterized by the process of an epoxy polymer matrix incorporated with 30% by volume of curaua fabric functionalized with graphene oxide. Manufacturing process characterized by a preparation of the composite described in claim 3 comprises the following steps Accommodate the curaua fabric functionalized with graphene oxide, corresponding to the desired proportion of 30% by volume in a suitable metallic mold; Add 70 vol.% of fluid still epoxy resin and cover the mold. The processing details of claim 4 are characterized by: Rectangular metallic mold with ballistic plate dimensions for use in personal vest or military vehicle; Apply a pressure of 5 MPa to the covered mold, already filled with the fabric and epoxy resin, at room temperature for a period of 5 hours. The process characterized by claims 3 to 5 makes it possible to manufacture plates up to 50 mm thick and side dimensions up to 300 mm in metallic steel-based molds specified for this purpose. The process characterized by claim 6 consists of demolding the plate with the aid of fitting screws facilitated by the use of silicone grease, previously applied to the internal surface of the mold. The composite plate characterized by a curaua fabric functionalized with graphene oxide reinforcing an epoxy matrix is suitable for use as a ballistic armor layer to protect against rifle shooting 7.62 mm or 5.56 mm caliber ammunition. 7 The ceramic material characterized by thicknesses of 7, 8, 9 and 10 mm comprising the following steps Use alumina (AI2O3) doped with niobium (Nb20s) in the proportion of 4% by mass as hexagonal shaped tiles; The powders of alumina, niobium and polyethylene glycol, in liquid phase, are weighed and stored in an alumina ball mill for 12h; Leave for 48 hours in a stove at 80 ° C for drying. Manufacturing process characterized by a preparation of the ceramics described in claim 9 comprises the following steps Maceration and sieving to obtain the powder; Pressing under a pressure of 30 MPa; Green bodies are taken to the furnace to be sintered. Multilayer armor, characterized by a composite plate of the present invention is glued with polyurethane adhesive to a ceramic front layer, responsible for eroding the projectile and attenuating its impact. Composite in the multilayer ballistic system characterized by the function of capturing the ceramic and projectile fragments resulting from the frontal impact. The reduction in the thickness of the ceramic material characterized by the decrease in both cost and weight. |
OPTIMIZATION OF MULTILAYER ARMOR SYSTEM OF EPOXY MATRIX COMPOSITE WITH CURAUA FABRIC FUNCTIONED WITH GRAPHENE OXIDE
Field of the Invention
[001] The present invention describes optimization of the thickness of the first layer and consequently reduction of the weight of a multilayer armor system. The system consists of an alumina ceramic as the first layer and epoxy matrix composite reinforced with curaua fabric functionalized with graphene oxide as the second layer. This composite has characteristics suitable for application in multilayer ballistic armor aiming to protect against rifle shooting with high impact ammunition. The reduction in thickness presents results within those required by the standard, even with 7 mm of first layer, and also a reduction in cost and weight. The present invention also discloses the process for making the material.
Background of the Invention
[002] Materials composed of epoxy matrix reinforced with natural fibers or fabrics, produced from these fibers, have been used since the middle of the 20th century in industrial sectors such as automotive and civil construction. However, there is no record of use in armor for ballistic protection.
[003] Today ballistic protection applied in personal vests and military vehicles, in addition to metallic and ceramic materials might also use, polymeric compounds reinforced with fibers or synthetic fabrics are also used.
[004] Standing alone, polymeric composite materials reinforced with natural fibers or fabrics do not have satisfactory ballistic performance. However, as an intermediate part of a multilayer system with front ceramic, they present performance comparable to synthetic materials and 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 modifier solid adhesion, 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] WO2010 Z 091476-A1 (EUA, 2010), describes a “Ballistic fabric composed of
65 to 80% polyamide fibers intertwined with 20 to 35% animal or cotton fibers. The preferred animal fiber is wool, and the preferred blend is 25% wool with 75% polyamide fibers. The preferred polyamide is Kevlar”. Unlike the present invention, only % of natural fiber fibers, animal or cotton, are mixed with % of synthetic fibers.
[007] JP5877431-132 (Japan, 2011 ) describes a “A fiber-reinforced composite material comprises a corrugated composite fiber yarn 1 that is formed by the wrapped point of a wrapping yarn 5 of a thermoplastic synthetic fiber yarn in a fiber bundle carbon 3 and / or a natural fiber yarn 4 with these yarns subject to varying tension ”. However, the composite uses only synthetic, thermoplastic or carbon fibers.
[008] WO2012 I 093167-A1 (France, 2012) describes an “Injectable composite material, including: (a) 28 to 95% by weight of a polypropylene I polyethylene copolymer; (b) 0 to 10% by weight of a flow intensifier; (c) 1 to 20% by weight of an impact modifier; (d) 1 to 20% of compatibilizing agent; and (e) 3 to 70% by weight of natural fibers, wherein the polypropylene I polyethylene copolymer forms a matrix. The invention also relates the method for preparing said composite material, as well as a method for using it in the manufacture of parts by injection or overmoulding”. Although it is a composite reinforced with natural fiber, there is no indication for any situation, for use in ballistic armor.
[009] The document CN207904438-V (Chile, 2018) describes “Yarn resists and durable based on the mixture of natural jute and PET, which consists of a composite that comprises the jute fiber layer, the polypropylene fiber layer, the PET fiber layer, polyurethane fiber layer, adhesive layer and nylon fiber layer ”. Although it contains jute fiber, there is no indication that the wire can be used for shielding.
[0010] None of the patent documents mentioned above is similar to the present invention as they do not specifically deal with a composite reinforced exclusively with natural fiber (curaua fabric functionalized with graphene oxide) for use in multilayer armor system for personal ballistic protection.
Summary of the Invention
[0011] The general objective of the invention is to optimize the thickness of the heavier first ceramic layer and consequently reduce the weight of the multilayer armor system.
[0012] The specific objective is to manufacture ceramic plates of varying thickness 7, 8, 9 and 10 mm.
[0013] The manufacture of ceramics comprises maceration and sieving to obtain the powder. Pressing under a pressure of 30 MPa and generating green bodies that are taken to high temperature furnace to be sintered.
[0014] The final objective of this invention is to reduce the thickness of the ceramic material, with characterizes both decrease in cost and weight.
Detailed Description of the Invention
[0015] The materials used in this invention correspond to: (i) liquid epoxy resin together with the hardener in the proportion of 13% by weight, both commercially available in Brazil; (ii) curaua fabric functionalized with graphene oxide. The curaua fabric and the graphene oxide will be produced by the inventors.
[0016] The manufacture of the composite plate is made in a steel mold with a filling base and a closing cap. Screws connecting the two parts of the mold allow complete sealing and ease of demoulding. [0017] The steel mold described in item [0017] is produced to order in a specialized machine shop, found in any major city in the country.
[0018] To facilitate the demoulding of the plate, silicone grease, available in Brazil, is applied before the process, applied to the internal surfaces of the mold.
[0019] The manufacturing process consists of inserting rectangular cuts of the cured fiber functionalized with graphene oxide, of the same internal dimension as the mold, with epoxy resin mixed with the hardener in the proportion of 13% by weight. The amount of 30% of curaua fabric functionalized with graphene oxide and is determined in advance based on the density of the materials used.
[0020] After filling the mold with the cured fiber functionalized with graphene oxide and with the liquid resin, the mold lid is closed, closed with the aid of screws. The filled mold is then subjected to pressure in a hydraulic press, with a capacity of 30 tons, and commonly available in Brazil.
[0021] The mold installed in the press and subjected to a pressure of 5 MPa that allows the complete flow of the liquid resin through the cured fiber functionalized with graphene oxide.
[0022] The filled and pressurized mold remains for 5 hours at room temperature, which allows the epoxy resin to harden by the action of the hardener.
[0023] The demoulding of the plate is carried out by the reverse action of the screws that sealed the plate.
[0024] The demoulded plate is taken to an oven for post-curing of the epoxy matrix at controlled temperature and time to achieve maximum strength and toughness of the composite.
Ballistic Armor Composite Use
[0025] The main purpose of the epoxy composite material reinforced with curaua fabric functionalized with graphene oxide is to use it in the form of a plate for a multilayer armor system to protect against rifle shooting with high impact ammunition. [0026] This protection corresponds to level III of the international standard related to projectile caliber 7.62 mm or 5.56 mm.
[0027] In the multilayer armor system, ceramic tiles make up the front layer responsible for the erosion of the projectile and dissipation of much of the impact energy. The composite plate, as a second layer, is glued to the ceramic tiles with polyurethane adhesive.
[0028] The composite plate, as a second layer, has the function of capturing the cloud of fragments resulting from the impact of the projectile against the front layer of ceramic platelets that are completely shattered.
[0029] The capture of the fragments by the composite plate occurs by mechanisms of incrustation in the curaua fabric functionalized with graphene oxide. The cloud of fragments, both metallic of the projectile and ceramic of the frontal layer are mostly capture by the curaua fibers in the fabric functionalized with graphene oxide.
[0030] The amount of 30% of curaua fabric functionalized with graphene oxide in the composite is sufficient to prevent fragmentation of the brittle polymeric epoxy matrix. This allows the composite plate to maintain its integrity to protect against subsequent rifle shootings.
[0031] The ballistic performance of the epoxy composite plate reinforced with curaua fabric functionalized with graphene oxide is comparable to that of plates, with the same dimension, made with synthetic fabrics such as Kevlar® and Dyneema® (UHMWPE) which are at least 5 times more expensive.
[0032] The reduction in thickness presents results attending the requirements of the standard, even with 7 mm thick front ceramic layer, and also a reduction in both weight and cost, with 30% of curaua fabric functionalized with graphene oxide in the composite, as part of multilayer armor system.