BE1026608B1 - GRAVE WALL BASED TISSUE FOR HIGH PRESSURE APPLICATIONS - Google Patents

Abstract

The invention relates to the field of fabrics, composite materials made therewith, parts for manufacturing such fabrics and specific uses for said fabrics.

Description

GRAVE WALL BASED TISSUE FOR HIGH-PRESSURE APPLICATIONS

Technical field

The invention relates to the field of fabrics, composite materials made therewith, parts for manufacturing such fabrics and specific uses for said fabrics.

Background of the invention

For certain demanding use cases, e.g. High pressure conditions, such as found in certain storage tank applications, for example, existing fabrics are not sufficiently suitable. Graphene is known for its good properties, but manufacturing graphene is difficult (and expensive). Therefore, according to the prior art, graphite is oxidized to graphite oxide, from which sheets are subsequently made, and reduction is applied to the graphene (sheets). However, such sheets are irregular, there are holes in the structure and therefore the required properties for our use cases are not provided.

Object of the invention

It is the object of the invention to provide suitable fabrics, in particular through the use of graphene sheets.

Summary of the invention

In a first aspect of the invention, the invention provides a fabric made with a strip of material made from (high quality) graphene sheets, more particularly a mesh or cloth-like fabric made with a strip of material made of (high quality ) graphene sheets.

In a second aspect of the invention, the invention provides a composite material comprising the fabric embedded in a matrix of a second (polymer) material.

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In a third aspect of the invention, the invention provides a strip of material (suitable for use in a weaving, braiding, knitting or sewing process), said strip material being made from (high quality) graphene sheets.

In a fourth aspect of the invention, the use of said fabrics under high pressure conditions (more than 750 bar, near 1500 bar), more particularly in the context of gas storage, is described.

Overview of the drawings

Figure 1 shows two embodiments for fabricating the strips, one with CVD and cut (left) and one with CVD, fold and cut (right).

Figure 2 shows two similar embodiments for fabricating the strips, one with CVD and cut (left) and one with CVD, fold and cut (right), but emphasizes the multi-layered aspect through repeated CVD growth.

Figure 3 (a) shows the subsequent use of said strips in a weaving, braiding, knitting, stitching step, followed by embedding in a polymer, while (b) the sheet, strip or more particularly fiber used in the fabric.

Figure 4 (a) schematically shows the multilayer (here 2) aspect of the sheet, (b) shows the use of the support; and (c) demonstrates folding in such a case.

Description of the invention

In the further description, the words fabric, strip and fiber are defined as follows: fabric means a cloth or other material produced by weaving threads or fibers. Alternatively, braiding, knitting and / or stitching is used. By strip is meant a narrow ribbon or a band-like piece of material. By sheet is meant a (rectangular) (rather large and thin) piece of material. By fiber is meant a fabric that is significantly longer than wide, and is often used in the manufacture of other materials such as a fabric.

General considerations

-3 BE2019 / 5085

In contrast to the prior art, the starting base for the graphene sheets of the invention is not graphite oxide but (pure) graphene made by a CVD process (as further explained), more particularly multilayer graphene sheets.

In an exemplary embodiment, the number of layers may be about 5000.

In an exemplary embodiment, the sheets are provided in strips 15 cm wide and 45 m long.

The (pure) (multilayer) graphene tapes are cut into strips, more particularly suitable in fibers or other structure suitable for making a fabric, possibly embedded in a suitable polymer.

Contrary to the prior art, the starting basis for the graphene sheets according to the invention is not the growth of the graphene made by a CVD method on top of an existing structure (metal mesh), but first an independent growth of the aforementioned (pure ) (multilayer) graphene sheets, which are then cut into strips for the purpose of achieving a stronger structure, for example by creating a woven structure.

Those (woven) structures can be combined with polymers to form a composite material.

Specific considerations

In a particular embodiment of the invention, the graphene is made by a chemical vapor deposition (CVD) method, in which a gaseous carbon source is bubbled through a reaction chamber where carbon is deposited on the surface of a metal substrate. The result is a continuous graphene film with a large surface (= monolayer graphene). By repeating this process, we can grow the monolayer graphene into a multilayer variant that can consist of thousands of monolayers stacked on top of each other (= multilayer graphene).

In a specific embodiment, a hybrid sheet material is provided. A fiber metal laminate is a hybrid material composed of alternating layers of a metal, a graphene layer and a polymer. The metal is copper, tin or other metal or metal alloy.

-4BE2019 / 5085

This layer is covered with monolayer or multilayer graphene. The graphene layer is impregnated with a polymer that forms a hybrid sheet material after curing at different temperatures. Different sheets can be built together or stacked after pretreatment of the metal surface.

In the invention, a fiber is more specifically defined as a structure of great length compared to its diameter. We define the length as L and the diameter as D with the aspect ratio L / D. The length of the fiber must take into account short or staple fibers (L / D < ⁰⁰ ) of infinite length (L / D = <= <>).

With regard to the diameter of the fiber, different shapes of fibers are possible in addition to a round shape. Different cross sections are possible. We call kidney-shaped, star-shaped, triangular-shaped and any other cross-section. We define the titer T as the mass per unit length expressed in intex or den.

In a particular manufacturing embodiment, the graphene sheet is cut into narrow bands ranging from nanometers to micrometers or centimeters, nanofibers or 1mm bands to any width (cm or more) or even faces or sheets. The tapes or fibers can be covered, embedded or treated with a polymer of any type. The graphene fiber or tape prepared as such can be manually transformed into a mesh-like or cloth-like structure (i.e., by a manual method) or by another method. Continuous roving, woven roving, chopped skein mat, chopped skein, yarn, fabric, ... The individual fibers or tapes are collected as strands consisting of several hundred individual filaments. The rovings are a collection of continuous strands. Woven roving mats are produced by weaving the rovings. Chopped strands are produced by cutting the strands and spraying these short strands with a binder over a flat conveyor belt. Yarns are twisted fibers. Two-dimensional (2D) and three-dimensional (3D) fabric architectures and tri-axial fabrics can be made from fibers, strands, yarns etc.

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In a specific embodiment, the textile is made by weaving, braiding, knitting, sewing or any other method and by non-woven techniques. The 2D woven fabrics can be made as a uni-weave fabric structure with one yarn set or as a biaxial non-crimped fabric with two sets of fibers for warp and fill. Basic textile types are uniform plain, twill, satin and all derivative weaves known as basket weaving, leno weaving and any other weave to be made.

In a further particular embodiment, an integrated 2D-shaped fabric can be developed into sandwich structures woven in different shapes. Triaxial fabric is made with three sets of yarns; bias, warp and filling in two variants; loosely woven and tightly woven or another variant.

In one embodiment, a structure is manufactured as multilayer to achieve required structural thickness achieved using the above 2D fabrics. To improve the off-plane properties, these 2D fabrics are formed by sewing or quilting or by some other method. 2D braided fabric can be made from intertwined yarns that form a braided fabric surface in the following patterns: diamond, ordinary hercules or any other pattern. 2D braided fabric can be layered to the required thickness and consolidated to form a rigid composite. Triaxial braided fabric can be formed when the yarns interlock around the axial yarns at about 45 ° or any other direction. Knitted fabric structure, is formed by the interlocking of a yarn system in continuous connecting vertical columns (wale) and horizontal rows (course) of loops.

Composite materials are a combination of two or more materials in such a way that there are certain desirable properties or improved properties. In a composite, the discontinuous component is called reinforcement, and the continuously surrounded reinforcement is called the matrix.

In an embodiment PMC, polymer matrix composites are described. The matrix can be classified as a thermoplastic, thermosetting or elastomeric polymer. As a thermosetting polymer, we use e.g. pure polymer or a mixture of: polyester resin of

-6BE2019 / 5085 any type, epoxy resin of any type, vinyl ester resin of any type, polyurethane of any type, phenolic resin of any type, polyimide resins of any type. As a thermoplastic polymer, we use for example: polyamides of any type, polyethylene of any type, polypropylene of any type, polystyrene of any type, polyethylene terephthalate of any type, polyether ether ketone of any type, polycarbonates of any type, polyphenylene sulfide of any type, polysulfone of any type, thermoplastic polyimides of any type. As elastomer we use for example: EPR ethylene propylene rubber, EPDM, CSM, BR, NBR, SBR, NR, CR or silicone rubber of any type. Pre-impregnated fibers, yarns, filaments, strands, rovings, roving mats and fabrics can be used as reinforcements or as an SMC sheet molding compound for the production of a semi-finished product, or as prepreg tapes or plates for developing larger structures, or as a filament wound around a structure. The commonly used thermosetting resins manufacturing methods are, for example, hand lay-up, RTM resin transfer molds, resin infusion, autoclave processing, compression molding, filament winding, pultrusion. For thermoplastics we use e.g. injection molding, reinforced reaction injection molding, thermoforming. The final product can be a composite or semi-finished product master batch.

Final considerations

It is worth emphasizing that the invention provides a technical solution to measures proposed in the context of climate change, such as hydrogen gas combustion vehicles that require high pressure gas storage (tanks).

The invention provides such a technical solution to such cases by recognizing that materials of greater strength than the prior art materials are required, even if they are graphene-based, more particularly that another way of treating such to manufacture materials is required given that existing manufacturing methods are the root cause of the lack of performance, moreover, the resulting materials are provided in a manner suitable for such tank manufacturing processes.

Claims (15)

Conclusions Composite material (120), comprising a (mesh or cloth-like) fabric (110), made with a strip of material (100), made of graphene sheets (50), preferably with a thickness / width of less than 15 cm, embedded in a matrix of a second material, preferably a polymer. Composite material according to claim 1, comprising a plurality of said fabrics on top of each other. Composite material according to claim 1 or 2, wherein the (mesh or cloth-like) fabric (110), being a woven, braided, knitted or sewn fabric with the strip of material, preferably applied as a fiber, preferably twisted fiber, preferably with a diameter of less than 0.5 mm. The composite material according to claim 3, wherein the (mesh or cloth-like) fabric (110), wherein a number of fibers is oriented in a first direction, while a different number of fibers is oriented in a second direction, is different from the first direction, preferably the first and second directions are orthogonal. The composite material according to claim 3, wherein the (mesh net or cloth-like) fabric (110), wherein a number of fibers is arranged in a mesh-like structure, preferably a honeycomb. A strip of material (100), suitable for use in a weaving, braiding, knitting or sewing process, the strip of material being made of graphene sheets, preferably applied to a backing layer (300) on a single side of the sheet, preferably with a thickness / width of less than 15 cm, the graphene sheets being made by a chemical vapor deposition (CVD) method (10). The strip of material according to claim 6, which is a fiber, preferably a twisted fiber and preferably with a diameter of less than 0.5 mm. The strip of material according to claims 6 or 7, wherein said graphene sheets are multilayer graphene sheets. -8BE2019 / 5085 The strip of material according to claims 6, 7 or 8, wherein the strips are cut from the graphene sheets, preferably after folding the sheets with a single-sided carrier layer as a sandwich. A strip of material (100) suitable for use in a weaving, braiding, knitting or sewing process, the strip of material being made of graphene sheets, preferably applied to a backing layer (300) on a single side of the sheet, preferably with a thickness / width of less than 15 cm, the strips being at least partially covered with a third material, preferably a polymer. Use of a composite material according to claims 1 to 5 under high pressure conditions (more than 750 bar, close to 1500 bar), more particularly in the context of gas storage, preferably to reinforce the housing of the gas storage tank, through the fabric around the wrap the housing. Use according to claim 11, wherein the gas is hydrogen stored in a vehicle as a source of the vehicle's engine. A method of manufacturing a storage tank suitable for use in claim 11 or 12) by using molds, preferably rotational molds, preferably wherein a composite material according to claims 1 to 5 is provided on the inside of the mold. A method of increasing the strength of a composite material comprising strips of material made of graphene sheets and a matrix, the method comprising: providing one or more (mesh or cloth-like) fabrics (110) made, preferably woven braided, knitted or sewn (200), with those strips of material; and embed it (210) in a matrix. A method of manufacturing a strip of material suitable for use in a weaving, braiding, knitting or sewing process, wherein the strip of material is made from graphene sheets, preferably of less than 15 cm thickness / width, wherein the method comprises: providing high quality graphene sheets (10) (10), preferably applied to a support layer on a single side of the sheet; and cutting (20) these into strip material, preferably after folding (30) the sheets with a single-sided carrier layer as a sandwich, the graphene sheets being made by a chemical vapor deposition (CVD) method (10).