Forming material

Abstract

The present invention relates to a molding material comprising: a) a first nonwoven fibrous layer; b) a second nonwoven fibrous layer; and c) a resin layer, wherein the resin layer bonds the second nonwoven fibrous layer to a first surface of the first nonwoven fibrous layer, and the resin layer is exposed on a second surface of the first nonwoven fibrous layer.

Description

[Technical Field]

[0001] The present invention relates to molding materials, particularly but not exclusively to molding materials for surface applications. [Background technology]

[0002] The present invention relates to molding materials that provide an enhanced surface finish, the use of the molding materials in combination with one or more pre-impregnated fiber reinforcement (prepreg) layers to form laminate structures, the use of the molding materials in combination with dry (non-impregnated) fiber layers to form laminate structures, and methods of forming laminate structures using the molding materials. The present invention is particularly related to fiber-reinforced composite molding materials that can be cured at low temperatures and include a surface finish layer to provide molded articles with high quality surface finishes that require only minimal preparation after cure, and may be used particularly, but not exclusively, in the wind turbine and automotive industries.

[0003] Composite materials have well-established advantages over traditional construction materials, particularly in that they offer superior mechanical properties at very low material densities. As a result, the use of such composites is widespread in many industries, including the aerospace, automotive, marine, and wind turbine industries.

[0004] Prepregs, which comprise fiber arrays impregnated with a thermosetting resin such as an epoxy resin, are widely used in the production of such composite materials. Typically, several layers of such prepregs are "laid up" as needed, and the resulting assembly or laminate is placed in a mold and cured, usually by exposure to elevated temperatures, optionally under pressure, to produce a cured composite laminate. In another manufacturing technique, the fiber material is typically laid up within an enclosure into which a liquid resin system can be injected to encapsulate the fiber material and then cured to produce the finished product. The enclosure may exist entirely around the fiber material and the resin drawn in under vacuum (also known as vacuum bagging). Alternatively, the enclosure may be a mold, and the resin may be injected into the mold (also known as resin transfer molding), which may also be assisted by vacuum (also known as vacuum-assisted resin transfer molding). Similar to the systems previously described in connection with prepregs, the liquid resin system may be an epoxy resin, a cyanate ester resin, or a bismaleimide resin, and will also include a hardener for the particular resin.

[0005] However, without any surface treatment, composites produced by any of the above techniques often cure with a poor surface finish. This can manifest as a rough, wavy, or pinhole-like surface, or narrow grooves on the surface of a molded structure (where adjacent layers of prepreg are stacked to ensure a continuous layer). This tendency to form an uneven surface appears to be closely related to the roughness of the underlying reinforcement, and the problem becomes more pronounced the rougher the reinforcement. This can be particularly problematic in cases where rough reinforcement is used for structural rigidity but where a smooth surface finish is desired, such as in the manufacture of automotive body panels requiring a Class A finish, or in the manufacture of wind turbine blades.

[0006] GB2445929 discloses a fiber-reinforced composite molded product including a surface portion laminated to a structural portion, the surface portion being formed from a surface layer including a plurality of surface layer segments molded together to form a continuous surface layer, the surface layer comprising a first cured resin material carried on a sheet material carrier, the structural portion being formed from at least one layer of fiber-reinforced material and a cured second resin material, the at least one layer of fiber-reinforced material being formed from a plurality of segments each disposed on a respective surface layer segment, and each surface layer segment overlapping an adjacent segment of fiber-reinforced material.

[0007] The inventors have found that the surface quality of the molded parts of the above-mentioned document is still poor, as print-through of the underlying carrier material and fiber reinforcement material is evident, and the lay-up requires an overlap, which results in surface defects in the form of visible joint lines.

[0008] WO 2008 / 007094 discloses, in FIG. 2, a surface material comprising a surface layer including a resin layer, a veil, and a fleece layer. The resin layer contacts the mold surface, and the veil is tacked onto it. The fleece includes a resin strip that facilitates adhesion of the fleece layer to the veil, leaving the fleece layer only partially impregnated with resin. This material has the problem that the resin content of the surface layer is low, necessitating an increase in the resin content of any subsequent prepreg layers. This means that prepreg materials with significantly higher resin contents than usual (typically greater than 60% by weight) can only be used in combination with this surface material, which is complex, inefficient, and costly. Furthermore, because conventional reinforcing layers are impregnated across their entire surface, manufacturing the fleece layer with the resin strip is complex, therefore inefficient, and costly.

[0009] WO 2017 / 021147 discloses a surface material in Figure 2, which includes a surface layer including a resin layer sandwiched between a veil and a fleece layer. The veil layer contacts the mold surface, and the veil and fleece layers are bonded to the resin layer, so the veil and fleece layers are largely unimpregnated. This facilitates the release of any air trapped in the layup near the mold surface. However, this material still suffers from the problem of a low resin content in the surface layer, which requires increasing the resin content in any subsequent prepreg layers, which is complex, inefficient, and costly. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to avoid or at least mitigate the above problems and / or to provide an improvement generally. [Means for solving the problem]

[0011] According to the present invention there is provided a moulding material, preferably a surfacing material, the use of the moulding material and a method for producing a laminate structure as defined in any of the appended claims.

[0012] The present invention provides the following: a) a first nonwoven fibrous layer; b) a second nonwoven fibrous layer; and c) Resin layer A molding material comprising: A molding material, wherein the resin layer bonds the second nonwoven fabric fiber layer to a first surface of the first nonwoven fabric fiber layer, and the resin layer is exposed on a second surface of the first nonwoven fabric fiber layer.

[0013] The present inventors have surprisingly found that by combining a nonwoven fiber layer with a resin layer exposed on the surface of the molding material of the present invention, excellent surface quality without pinholes can be obtained, and that the configuration of the molding material of the present invention also prevents defects in the surface appearance due to print-through of the carbon fiber reinforced layer.

[0014] The materials of the present invention also provide an excellent surface finish when used as a mold or tool contact layer when preparing laminate products using pre-impregnated and / or unimpregnated reinforcement materials in prepreg or injection systems.

[0015] Furthermore, the inventors have found that prepreg reinforcement layers can be used with this material where the resin content of the prepreg is between 30% and 45% by weight without any adverse effect on the surface appearance quality, allowing the use of standard prepreg materials in combination with this molding material, which avoids the need for increased resin content.

[0016] In a particular embodiment of the present invention, the molding material of the present invention can be provided as a facing layer, i.e., without any reinforcing layer, and therefore, in this embodiment, the molding material can consist essentially of a first nonwoven fibrous layer, a second nonwoven fibrous layer, and a resin layer. In another embodiment, the molding material can be provided as a reinforced facing layer, and in this embodiment, the molding material can include a reinforcing layer (reinforcement layer), with the second nonwoven fibrous layer located between the first nonwoven fibrous layer and the reinforcing layer. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 shows a schematic diagram of a molding material according to one embodiment of the present invention. [Figure 2] FIG. 2 shows a schematic diagram of another molding material according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Specific embodiments of the present invention will now be described in more detail by way of example as follows.

[0019] In the molding material of the present invention, the resin layer bonds the second nonwoven fibrous layer to the first surface of the first nonwoven fibrous layer, and the resin layer is exposed on the second surface of the first nonwoven fibrous layer. Therefore, the first nonwoven fibrous layer is generally completely saturated with the resin layer. Furthermore, in certain embodiments, the second nonwoven fibrous layer is at least partially impregnated, and optionally completely impregnated, with the resin of the resin layer.

[0020] In certain embodiments of the present invention, the resin layer comprises a formulated resin matrix comprising at least one resin component, at least one curative, and optionally a filler.

[0021] The resin matrix for forming the resin layer may include a thermosetting resin, such as a polyester resin, a polyurethane resin, a polyurethane / polyurea resin, a phenol-formaldehyde resin, a urea-formaldehyde resin, a vinyl ester resin, a cyanate ester resin, a polyimide resin, or an epoxy resin. Unlike thermoplastic resins, thermosetting resins harden irreversibly upon curing, making any molded articles produced therefrom less susceptible to deformation. In one embodiment, the first resin composition is a thermosetting resin composition, preferably an epoxy resin composition, i.e., a composition comprising an epoxy resin or a blend of epoxy resins.

[0022] The resin layer preferably comprises at least a multifunctional bisphenol epoxy resin material in combination with a urea-based curing agent. A preferred compounded resin matrix for this layer is M79 resin supplied by Hexcel Corporation.

[0023] In another embodiment of the invention, the compounded resin matrix comprises 1-10 wt. % of a filler, preferably a silica filler or an oleophilic phyllosilicate, preferably a fumed silica filler having a tapped density of 60 g / l, based on the weight of the compounded resin matrix. A preferred filler material is Aerosil R202 supplied by Evonik Industries.

[0024] The inventors have found that the inclusion of fillers reduces flow of the resin layer, which is beneficial in layups involving substantial vertical surfaces, such as in the construction of boat and yacht hulls.

[0025] The first and second nonwoven fibrous layers of the present invention preferably have the following properties and characteristics: The nonwoven fibrous layers may comprise any nonwoven fibrous material that is both air-permeable and resin-permeable. Suitable nonwoven fibrous carriers are lightweight, preferably weighing less than 100 g / m 2 Preferably, the thickness is less than 1 / 2 mm, but is tough enough to carry layers of resin and to withstand handling during lay-up and processing to form a composite part with a high quality appearance surface.

[0026] The nonwoven fibrous layer may comprise continuous or discontinuous fibers.

[0027] In one embodiment, the first nonwoven fibrous layer comprises a veil. In the context of the present invention, the term "veil" refers to a thin, lightweight (i.e., 100 g / m 2 refers to a nonwoven fabric, web, or fibrous reinforcement that is porous and has a basis weight of 1000 sq. mm or less (as defined below) and is porous.

[0028] In preferred embodiments, the first nonwoven fibrous layer typically comprises nonwoven fibers of a thermoplastic material, preferably fibers bound together using an organic binder to give the material structural integrity. In certain embodiments, the thermoplastic material comprises polyester, polyamide, preferably aliphatic or semi-aromatic polyamide, and / or a combination of polyester and polyamide. When present, the organic binder is typically present in an amount of 1 to 10 wt. %, based on the total weight of the first nonwoven fibrous layer.

[0029] The purpose of the first nonwoven fibrous layer is to act as a support or carrier for the resin layer, holding the resin on the exterior surface and controlling how the resin interacts with the surface of the mold or tool, thereby providing a good surface finish.

[0030] In one embodiment, the first nonwoven fibrous material has an openness between 1 and 10%, preferably between 2 and 89%, and / or a porosity between 75 and 350 μm 2 The mean open area is between .

[0031] In a further embodiment, the first nonwoven fibrous layer has a density of 1 to 80 g / m 2 , preferably 5 to 50 g / m 2 , more preferably 15 to 40 g / m 2 The base weight ranges from 1000 to 10 ...

[0032] In one embodiment, the first nonwoven fibrous layer has a ductility of about 2,300 L / m at an applied pressure of 200 Pa. 2 / sec (as measured in accordance with ASTM D737-18). Suitable thermoplastic fibrous materials in the form of a veil that may be used for the first nonwoven fibrous layer include those commercially available under the Optiveil® trade name, such as Optiveil T2761-00, available from Technical Fibre Products Limited, Burnside Mills, Kendal, Cumbria, United Kingdom.

[0033] Openness measurements can be performed using a Keyence VHX-6000 series digital microscope manufactured by Keyence (UK) Limited (Milton Keynes, Buckinghamshire, UK). To help highlight the open areas (area) when viewed on a computer monitor, the nonwoven material can be presented to the microscope by mounting it on a blue plastic card. The microscope is set to 175x magnification, the light output is set to maximum, and the gain dial setting is adjusted so that the open areas are clearly identifiable. The saved computer image shows a resolution of 2951002 μm. 2 Represents the total area of

[0034] Keyence software is then used to measure the average "open area" (i.e., the open space between fibers) and % openness. The image is also manipulated by adjusting the histogram sliders to create a two-color image, where one color represents the fibers and the other represents the open space. The software is then used to measure the area of all individual open spaces. This data is saved in a spreadsheet and can be used to calculate the total area occupied by open spaces (for purposes of calculating % openness) along with the average size of the open regions.

[0035] The second nonwoven fibrous layer can comprise a nonwoven fibrous material containing continuous or discontinuous fibers. The second nonwoven fibrous material can comprise nonwoven fibers of glass, carbon, polyester, polyamide, aramid (aromatic polyamide), or a combination thereof, optionally bonded together using an organic binder to provide structural integrity to the material. Preferably, the second nonwoven fibrous layer comprises a glass fiber material, a polyester material, a polyolefin polymer material, and / or a combination of the aforementioned materials.

[0036] Preferably, the second nonwoven fibrous carrier (carrier) comprises a nonwoven glass fiber material in the form of a veil. The organic binder, if present, may typically be present in an amount of 1 to 10% by weight, based on the total weight of the second nonwoven fibrous carrier. Generally, the second nonwoven fibrous material will have a slightly higher basis weight or surface density than the first nonwoven fibrous layer. In a preferred embodiment, the second nonwoven fiber has a surface density of 20 to 100 g / m. 2 in the range of 30 to 80 g / m 2 in the range of 30 to 60 g / m 2 Suitable nonwoven glass veils, mats or fleeces are commercially available from Johns Manville (Denver, Colorado, USA) under the trade name Evalith®, non-limiting examples of which include Evalith® ST-3022, S4030, and S5030, and from Taishan Fiberglass Inc. (Taian, Shandong, PR Special Economic Zone, China) under the trade name Changhai®, non-limiting examples of which include Changhai® S-SM30, S-SM50, S-HM30, and S-HM50.

[0037] The presence of the second nonwoven fibrous material helps prevent "print-through" from the fibrous reinforcement material of the structural reinforcement layer from appearing on the surface of the molded material after curing, and also ensures that sufficient second resin composition is retained in the surface reinforcement layer during curing, thereby avoiding the formation of narrow grooves or other surface irregularities due to insufficient resin. Like the first nonwoven fibrous material, the second nonwoven fibrous material can also help prevent air entrapment or aid in the dissipation of trapped air.

[0038] In certain embodiments of the present invention, the molding material does not include any reinforcing material, and therefore the molding material consists essentially of a first nonwoven fibrous layer, a second nonwoven fibrous layer, and a resin layer.

[0039] In an embodiment of the present invention according to the first aspect in which a reinforcing material is not present, the total resin content of the molding material may be included in the resin associated with the first nonwoven fibrous layer. The preferred total resin content of the molding material in this embodiment depends on the intended use of the molding material, but preferably the resin content of the molding material is in the range of 40 to 75 wt. % based on the weight of the molding material, and more preferably in the range of 50 to 60 wt. % based on the weight of the molding material.

[0040] In a second aspect of the present invention, the molding material of the present invention includes a reinforcing layer, and a second nonwoven fibrous layer is disposed between the first nonwoven fibrous layer and the reinforcing layer. The presence of the reinforcing layer helps to improve the structural integrity of the molding material, facilitating storage, transportation, and handling.

[0041] Preferably, the second nonwoven fibrous layer is sewn (stitched) onto the surface of the reinforcing layer, and this layer can be stitched with polyester yarn having a tex value in the range of 5 to 90 dtex, preferably 40 to 85 dtex, more preferably 70 to 85 dtex.

[0042] The structural reinforcing layer can take many forms, and typically a moulding material according to the second aspect of the invention will include several structural reinforcing layers, although in some applications a single layer may be sufficient.

[0043] The fiber reinforcement material may be in the form of a sheet, continuous mat, or continuous filament. In other embodiments, the fiber reinforcement material comprises short lengths of fiber, such as chopped strand mat. The fiber reinforcement material may be in the form of multiple fiber tows, each containing multiple fiber filaments to form each tow. The tows may be stitched or woven to form a fabric. The fibers may be composed of natural materials such as cotton, flax, hemp, wool, or silk; semi-synthetic materials such as rayon, viscose, or modal; or synthetic materials such as carbon, polyester, mineral, nylon, acrylic, glass, or aramid (aromatic polyamide). In a preferred embodiment, the fiber reinforcement comprises carbon or glass fibers.

[0044] In some embodiments, the fiber-reinforced material is in the form of a woven fabric. In other embodiments, the fiber-reinforced material comprises a unidirectional (UD) fabric, in which the majority of the fibers, rovings, or tows present in the fabric extend in only one direction, while a few fibers, rovings, or tows may extend in a direction different from the majority, for example, by cross-stitching to maintain the latter's unidirectional alignment. The fibers, rovings, or tows of a unidirectional fabric may be held in alignment by many different methods, including weaving, stitching, and bonding. As a result, such unidirectional fabrics may be woven or nonwoven (they may be woven or nonwoven). In further embodiments, the fiber-reinforced material comprises a unidirectional fabric combined with a biaxial or multiaxial fabric or mat, in which either component may be woven or nonwoven (they may be woven or nonwoven).

[0045] Woven and nonwoven fabrics suitable for use in composites are commercially available from specialized manufacturers, including, but not limited to, Chomarat Textiles Industries (Esher, Surrey, UK), Hexcel Reinforcements UK Limited (Narborough, Leicestershire, UK), and Zhenshi Group Hengshi Fiberglass Fabrics Co., Ltd. (Tongxiang Economic Development Zone, Jiaxing Zhejiang, 314500, China). In one embodiment, the woven or nonwoven fabric is a carbon or glass fiber fabric, such as BB200, BB600, or BB1200, where, for example, the designation BB1200 refers to a fabric with a basis weight of 1200 g / m. 2 This refers to biaxial glass cloth.

[0046] Hybrid or mixed fiber systems are also contemplated. The use of cracked (i.e., stretch-broken) or selectively discontinuous fibers may be advantageous to facilitate layup of the molding material according to the invention and improve its molding capabilities.

[0047] The basis weight of fiber reinforced materials is generally 40 to 4,000 g / m 2 In a preferred embodiment, the basis weight of the fiber is preferably 100 to 2,500 g / m 2 , more preferably 150 to 2,000 g / m 2 The range is.

[0048] The fiber reinforcement material for the structural reinforcement layer, or for multiple structural reinforcement layers, is typically a heavyweight non-crimp fabric such as glass cloth. Fibers with a density of 68 to 2400 tex (grams per kilometer) are particularly suitable for glass reinforcement.

[0049] In certain embodiments of the second aspect of the invention, the reinforcing layer may comprise at least two layers, each layer comprising unidirectional fibres, the unidirectional fibres of each layer may be in different directions.

[0050] In one embodiment, the unidirectional fibrous layer and the second nonwoven fibrous layer are stitched together, optionally using the same stitching thread.

[0051] The reinforcing layer preferably comprises a fiber reinforcement material and a compounded reinforced resin matrix, and in a preferred embodiment the compounded reinforced resin matrix has the same composition as the resin of the resin layer.

[0052] In embodiments of the present invention according to the second aspect, in which a reinforcing layer is present, the total resin content of the molding material may be contained in the resin associated with the first nonwoven fiber layer, or the resin may be dispersed throughout the material as several individual layers or as a single matrix. The preferred total resin content of the molding material in this embodiment depends on the intended use of the molding material and the weight of the reinforcing material, but preferably ranges from 5 to 60 wt. % based on the weight of the molding material. For example, in molding materials intended for use in infusion systems, the total resin content is preferably 5 to 50 wt. %, more preferably 5 to 20 wt. % based on the weight of the molding material. Similarly, in molding materials intended for use in combination with at least partially pre-impregnated materials without infusion, the total resin content is preferably 20 to 60 wt. %, more preferably 25 to 50 wt. % based on the weight of the molding material.

[0053] The present invention further provides for the use of the molding material of the present invention in combination with one or more pre-impregnated fiber reinforcement (prepreg) layers to form a laminate structure, the prepreg layers having a resin content in the range of 30 to 45 wt. % based on the weight of the prepreg material.

[0054] The present invention further provides for the use of the molding material of the present invention in combination with one or more resin-free (dry) fiber reinforced layers to form a laminate structure in a resin infusion process.

[0055] The present invention further provides: 1. A method for manufacturing a laminate structure, comprising: laying down a molding material according to the present invention on the surface of a mold or tool by contacting the layer of resin exposed on the second surface of the first nonwoven fibrous layer with the surface of the mold or tool; applying one or more layers of resin-free (dry) fiber reinforcement to the opposing surface of said molding material to form a laminate; infusing the laminate with an infusion resin; and curing the injected laminate; A method comprising:

[0056] In the method for producing a laminated structure of the present invention, the molding material used in this method may be the molding material according to the first aspect of the present invention, i.e., a molding material that does not include a reinforcing layer, or the molding material may be the molding material according to the second aspect of the present invention, i.e., a molding material that includes a reinforcing layer, particularly a molding material that includes a reinforcing layer and has a resin content in the range of 5 to 50 wt %, preferably 5 to 20 wt %, based on the weight of the molding material.

[0057] In the method for manufacturing a laminate structure according to the invention, at least one layer of pre-impregnated fiber reinforcement (prepreg) can be included in the stack before infusion with resin.

[0058] The method of manufacturing a laminate structure according to the present invention can use any conventional infusion process and infusion resin, depending on the intended use of the laminate structure.

[0059] drawing The invention will now be described, by way of example only, with reference to the accompanying drawings in which: FIG. 1 shows a schematic diagram of a molding material according to one embodiment of the present invention. FIG. 2 shows a schematic diagram of another molding material according to another embodiment of the present invention.

[0060] 1 shows a molding material 100 including a first nonwoven fibrous layer 102 and a second nonwoven fibrous layer 104. The first nonwoven fibrous layer 102 is exposed on its surface, but includes a resin layer 106 extending across the entire first nonwoven fibrous layer 102, and also contacting at least the second nonwoven fibrous layer 104 and optionally extending partially or completely within the second nonwoven fibrous layer. The first and second nonwoven fibrous layers 102, 104 are bonded together by the adhesive properties of the resin layer 106.

[0061] In a particular embodiment, the first nonwoven fibrous layer 102 has a fiber density of 15 g / m 2 the resin layer 106 is a nonwoven thermoplastic veil comprising a blend of polyamide and polyester materials having a weight of 65 g / m 2 the second nonwoven fibrous layer 104 is 50 g / m 2 The fleece is a glass fiber material having a weight of 1.0000.

[0062] In typical use, molding material 100 is placed in contact with a mold surface, with the top surface of resin layer 106 in contact with the mold. An additional, at least partially resin-preimpregnated reinforcing layer can be placed on top of molding material 100, i.e., in contact with second nonwoven fibrous layer 104, to build a composite layup that can then be cured to produce a composite part. In another use, molding material 100 is placed in contact with a tool surface, with the top surface of resin layer 106 in contact with the tool. An additional, unimpregnated (i.e., dry) reinforcing layer can be placed on top of molding material 100, i.e., in contact with second nonwoven fibrous layer 104, to build a composite layup that can then be infused with resin and cured to produce a composite part.

[0063] 2 shows a molding material 200 including a first nonwoven fibrous layer 202 and a second nonwoven fibrous layer 204. The first nonwoven fibrous layer 202 includes a resin layer 206 exposed on its surface, extending across the entire first nonwoven fibrous layer 202, and also contacting at least the second nonwoven fibrous layer 204 and optionally extending partially or completely into the second nonwoven fibrous layer. A fiber reinforcement layer 208 is disposed on the opposite surface of the second nonwoven fibrous layer 204. The first and second nonwoven fibrous layers 202, 204 are bonded together by tucks in the resin layer 206, while the second nonwoven fibrous layer 204 and the reinforcement layer 208 are bonded together by stitching. This allows the reinforcement layer 208 to remain dry and not impregnated with resin.

[0064] In a particular embodiment, the resin composition comprises a difunctional epoxy in combination with a urea-based curing agent; the first nonwoven fibrous layer 202 has a thickness of 15 g / m 2 the resin layer 206 is a nonwoven polyester veil having a weight of 140 g / m 2 the second nonwoven fibrous layer 204 has a weight of 50 g / m 2 It is a glass fiber fleece having a weight of 1.000g.

[0065] In a preferred embodiment, the reinforcing layer 208 is preferably in the form of two layers of unidirectional fibers combined to form a biaxial layer, preferably a biaxial layer with a + / - 45 degree orientation.

[0066] In a typical use, molding material 200 is placed in contact with a mold surface, with the top surface of resin layer 206 in contact with the mold. An additional reinforcing layer is placed on top of molding material 200 to create a composite layup that is then cured to produce a composite part. In another use, molding material 200 is placed in contact with a tool surface, with the top surface of resin layer 206 in contact with the tool. An additional unimpregnated (i.e., dry) reinforcing layer may be placed on top of molding material 200, i.e., this unimpregnated reinforcing layer may be placed in contact with second nonwoven fiber layer 204 to create a composite layup that may then be infused with resin and cured to produce a composite part.

[0067] Thus, a molding material is provided that can be used in combination with pre-impregnated fiber reinforcement (prepreg) layers having a resin content in the range of 30-45 wt. % based on the weight of the prepreg, and can also be used in combination with non-impregnated fiber reinforcement layers to form laminates in an injection system. [Example]

[0068] Example 1 A resin composition (Composition 1) was formulated from the following: 72.9 g Kukdo KFR136SL (semi-solid bisphenol A diglycidyl ether epoxy resin manufactured by Kukdo Chemical Company Limited, Seoul, Korea); 18.2 g Epikote® 828 (liquid bisphenol A diglycidyl ether epoxy resin manufactured by Hexion Inc., Columbus, Ohio, USA); 2.9 g Dyhard® UR500 (a powdered bifunctional latent uronic accelerator manufactured by Alzchem Group AG, Trostberg, Germany).

[0069] These ingredients were thoroughly mixed at a temperature of 50-60°C until the mixture reached a uniform consistency.

[0070] The molding material was constructed to have the following structure: (1) a layer of Evalith® S5030 (basis weight 50 g / m, manufactured by Johns Manville, Denver, Colorado, USA); 2 with glass fiber fleece); (2) Contains a blend of polyester and polyamide fibers, 15 g / m 2 a layer of lightweight, fully synthetic nonwoven fiber veil having a basis weight of 0.01 g (manufactured by Technical Fibre Products Limited, Burnside Mills, Kendal, Cumbria, UK); and (3) 65 g / m 2 A layer of resin composition 1 having a basis weight of

[0071] The combined layers were consolidated by passing through an S-wrap roller system heated to 80° C. to form a molding material corresponding to molding material 100 shown in FIG.

[0072] The molding material 100 was placed into a composite tool that had been treated with Zyvax® Watershield® (a silicone-free, water-soluble mold release agent, manufactured by Freeman Manufacturing and Supply Company, Avon, Ohio, USA), followed by three layers of BB1000 fabric (1000 g / m² manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, UK). 2 biaxial non-crimp glass fiber) and one layer of Bleeder Lease B (62 g / m obtained from Airtech Europe Sarl, Differentange, Luxembourg). 2 Siliconized nylon fabric) and injecting Hexion RIM R135 / RIM H137 (a liquid epoxy resin and hardener combination available from Hexion Inc., Columbus, Ohio, USA), followed by curing at 80°C for 6 hours at 1 bar pressure.

[0073] After cooling, the hardened molded parts were removed for inspection and further testing.

[0074] Example 2 A resin composition (Composition 2) was formulated from the same ingredients in the same amounts as Composition 1, but with the addition of 6 g of Aerosil® R202 (a hydrophobic fumed silica rheology modifier from Evonik Resource Efficiency GmbH, Hanau-Wolfgang, Germany).

[0075] The ingredients were thoroughly mixed at a temperature of 50-60°C until the mixture had a uniform consistency.

[0076] The molding material was constructed to have the following structure: (1) a layer of LBB1200 fabric (Hexcel Reinforcements UK Limited, Narborough, Leicestershire, UK, 1250 g / m 2triaxial non-crimp glass fiber); (2) a layer of Evalith® S5030 (Johns Manville, Denver, Colorado, USA, basis weight 50 g / m 2 of fiberglass fleece); (3) Contains a blend of polyester and polyamide fibers, 15 g / m 2 a layer of lightweight, fully synthetic nonwoven fiber veil having a basis weight of 0.01 g (manufactured by Technical Fibre Products Limited, Burnside Mills, Kendal, Cumbria, UK); and (4) 140 g / m 2 A layer of resin composition 2 having a basis weight of

[0077] The combined layers were consolidated by passing through an S-wrap roller system heated to 80° C. to form a molding material corresponding to molding material 200 shown in FIG.

[0078] Molding material 1 was placed into a composite tool that had been treated with Zyvax® Watershield® (a silicone-free, water-soluble mold release agent, manufactured by Freeman Manufacturing and Supply Company, Avon, Ohio, USA), followed by three layers of BB1000 fabric (1000 g / m², manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, UK). 2 biaxial non-crimp glass fiber) and one layer of Bleeder Lease B (62 g / m obtained from Airtech Europe Sarl, Differentange, Luxembourg). 2 Siliconized nylon fabric) and injecting Hexion RIM R135 / RIM H137 (a liquid epoxy resin and hardener combination available from Hexion Inc., Columbus, Ohio, USA), followed by curing at 80°C for 6 hours at 1 bar pressure.

[0079] After cooling, the hardened molded parts were removed for inspection and further testing.

[0080] Example 3 Resin composition 2 was used to form a molding material having the following structure: (1) 400g / m 2 a layer of resin composition 2 having a basis weight of (2) a layer of LBB1200 fabric (Hexcel Reinforcements UK Limited, Narborough, Leicestershire, UK, 1250 g / m 2 triaxial non-crimp glass fiber); (3) a layer of Evalith® S5030 (Johns Manville, Denver, Colorado, USA, basis weight 50 g / m 2 of fiberglass fleece); (4) Contains a blend of polyester and polyamide fibers, 15 g / m 2 a layer of lightweight, fully synthetic nonwoven fiber veil having a basis weight of 0.01 g (manufactured by Technical Fibre Products Limited, Burnside Mills, Kendal, Cumbria, UK); and (5) 400 g / m 2 A layer of resin composition 2 having a basis weight of

[0081] The combined layers were consolidated by passing through an S-wrap roller system heated to 80° C. to form a molding material corresponding to molding material 200 shown in FIG.

[0082] The molding material 200 was placed in a composite tool treated with Zyvax® Watershield® (a silicone-free, water-soluble mold release agent from Freeman Manufacturing and Supply Company, Avon, Ohio, USA) with the resin composition layer (5) adjacent to the mold surface. Two layers of HexPly® 79 (a prepreg from Hexcel GmbH, Neumarkt, Germany) were placed on top of the molding material in the mold, next to the resin layer (1), and the combination was then cured under vacuum at 80°C and 1 bar pressure for 6 hours. After cooling, the cured molded part was removed for inspection and further testing. Aspects or embodiments that may be included in the present invention are summarized as follows. [1]. a) a first nonwoven fibrous layer; b) a second nonwoven fibrous layer; and c) Resin layer A molding material comprising: A molding material, wherein the resin layer bonds the second nonwoven fabric fiber layer to a first surface of the first nonwoven fabric fiber layer, and the resin layer is exposed on a second surface of the first nonwoven fabric fiber layer. [2]. The molding material according to item 1, wherein the second nonwoven fiber layer is at least partially, and optionally completely, impregnated with the resin of the resin layer. [3]. The molding material according to item 1 or 2, wherein the resin layer comprises a formulated resin matrix comprising at least one resin component, at least one curing agent, and optionally a filler. [4]. 4. The molding material according to item 3, wherein the formulated resin matrix comprises at least a multifunctional bisphenol epoxy resin material in combination with a urea-based curing agent. [5]. The molding material according to item 3 or 4, wherein the compounded resin matrix contains 1 to 10% by weight of a filler, preferably a silica filler or an oleophilic phyllosilicate, based on the weight of the compounded resin matrix. [6]. The first nonwoven fiber layer preferably has a density of 1 to 80 g / m 2 , more preferably 5 to 50 g / m 2 , and even more preferably 10 to 40 g / m 2 6. The molding material according to any one of the above items 1 to 5, comprising a polyester or aliphatic or semi-aromatic polyamide fiber material having a basis weight in the range of [7]. The second nonwoven fabric fibrous layer preferably has a basis weight greater than that of the first nonwoven fabric fibrous layer, more preferably 20 to 100 g / m 2 , and even more preferably 30 to 80 g / m 2 , and most preferably 30 to 60 g / m 2 7. The molding material according to any one of items 1 to 6, comprising a glass fiber material, or a polyester material or a polyolefin polymer material, and / or a combination of the aforementioned materials, having a basis weight in the range of [8]. 8. The molding material according to any one of items 1 to 7, which essentially consists of the first nonwoven fiber layer, the second nonwoven fiber layer, and the resin layer. [9]. Item 9. The molding material according to item 8, wherein the resin content of the molding material is in the range of 40 to 75% by weight, preferably 50 to 60% by weight, based on the weight of the molding material.

[10] . The molding material according to any one of items 1 to 7, wherein the molding material includes a reinforcing layer, and the second nonwoven fabric fiber layer is disposed between the first nonwoven fabric fiber layer and the reinforcing layer.

[11] . 11. The molding material according to item 10, wherein the second nonwoven fiber layer is sewn to the surface of the reinforcing layer.

[12] . Item 12. The molding material according to item 10 or 11, wherein the reinforcing layer comprises at least two layers, each layer comprising unidirectional fibers.

[13] . 13. The molding material according to item 12, wherein the unidirectional fibers of each layer are in different directions.

[14] . Item 14. The molding material according to item 12 or 13, wherein the multiple layers of unidirectional fibers and the second nonwoven fiber layer are sewn together.

[15] . 15. The molding material according to any one of the above items 10 to 14, wherein the reinforcing layer comprises a fiber reinforcing material and a blended reinforcing resin matrix.

[16] . Item 16. The molding material according to item 15, wherein the compounded reinforced resin matrix has the same composition as the resin of the resin layer.

[17] . 17. The molding material according to any one of items 10 to 16, wherein the resin content of the molding material is in the range of 5 to 60% by weight, preferably 5 to 50% by weight, more preferably 5 to 20% by weight, based on the weight of the molding material, or 20 to 60% by weight, more preferably 25 to 50% by weight, based on the weight of the molding material.

[18] . 18. Use of the molding material according to any one of the above items 1 to 17 in combination with one or more pre-impregnated fiber reinforcement (prepreg) layers to form a laminate structure, The prepreg has a resin content in the range of 30 to 45% by weight based on the weight of the prepreg material.

[19] . 18. Use of the molding material according to any one of the above items 1 to 17 in combination with one or more resin-free (dry) layers of fiber reinforcement to form a laminate structure in a resin infusion process.

[20] . 1. A method for manufacturing a laminate structure, comprising: bringing the layer of resin exposed on the second surface of the first nonwoven fiber layer into contact with the surface of a mold or tool, and laying down the molding material according to any one of items 1 to 17 on the surface of the mold or tool; applying one or more layers of resin-free (dry) fiber reinforcement to the opposing surface of said molding material to form a laminate; infusing the laminate with an infusion resin; and curing the injected laminate; A method comprising:

[21] . 21. The method according to item 20, wherein the molding material is the molding material according to item 8 or 9.

[22] . The method according to item 20, wherein the molding material is the molding material according to any one of items 10 to 16, and the resin content of the molding material is in the range of 5 to 50% by weight, preferably 5 to 20% by weight, based on the weight of the molding material.

[23] . 23. The method according to any one of the above items 20 to 22, wherein at least one layer of pre-impregnated fiber reinforcement (prepreg) is included in the laminate before infusion of resin.

Claims

1. a) a first nonwoven fiber layer, the first nonwoven fiber layer having an openness of 1 to 10%; b) a second nonwoven fibrous layer; c) a fiber-reinforced layer, wherein the second nonwoven fiber layer is disposed between the first nonwoven fiber layer and the fiber-reinforced layer, and the second nonwoven fiber layer is sewn to a surface of the fiber-reinforced layer, wherein the fiber-reinforced layer does not contain resin; and d) Resin layer Including, the resin layer bonds the second nonwoven fibrous layer to a first surface of the first nonwoven fibrous layer, and the resin layer is exposed on a second surface of the first nonwoven fibrous layer; the first nonwoven fabric fiber layer is completely impregnated with the resin of the resin layer, the second nonwoven fabric fiber layer is partially impregnated with the resin of the resin layer, and the fiber reinforced layer is not impregnated with the resin of the resin layer; Molding material.

2. The molding material of claim 1 , wherein the resin layer comprises a formulated resin matrix comprising at least one resin component, at least one curing agent, and optionally a filler.

3. 3. The molding material of claim 2, wherein said formulated resin matrix comprises at least a multifunctional bisphenol epoxy resin material in combination with a urea-based curing agent.

4. 4. The molding material according to claim 2 or claim 3, wherein the compounded resin matrix comprises 1 to 10 wt. % of a filler, preferably a silica filler or an oleophilic phyllosilicate, based on the weight of the compounded resin matrix.

5. The first nonwoven fiber layer preferably has a density of 1 to 80 g / m ２ , more preferably 5 to 50 g / m ２ , and even more preferably 10 to 40 g / m ２ 5. The molding material according to claim 1, comprising a polyester or aliphatic or semi-aromatic polyamide fiber material having a basis weight in the range of 1.0 to 4.

0.

6. The second nonwoven fibrous layer preferably has a basis weight greater than that of the first nonwoven fibrous layer, more preferably 20 to 100 g / m ２ , and even more preferably 30 to 80 g / m ２ , most preferably 30 to 60 g / m ２ 6. The molding material according to claim 1, comprising a glass fiber material, or a polyester material or a polyolefin polymer material, and / or a combination of the aforementioned materials, having a basis weight in the range of 1:

1.

7. The molding material according to any one of claims 1 to 6, wherein the fiber-reinforced layer comprises at least two layers, each layer comprising unidirectional fibers.

8. 8. The molding material of claim 7, wherein the unidirectional fibers of each layer are in different directions.

9. 9. The molding material of claim 7 or claim 8, wherein the layers of unidirectional fibers and the second nonwoven fiber layer are sewn together.

10. The molding material according to any one of claims 1 to 9, wherein the fiber reinforced layer comprises a fiber reinforced material and a compounded reinforced resin matrix.

11. 11. The molding material of claim 10, wherein the compounded reinforced resin matrix has the same composition as the resin of the resin layer.

12. The resin content of the molding material is 5 to 60% by weight based on the weight of the molding material, preferably 5 to 50% by weight based on the weight of the molding material, more preferably 5 to 20% by weight, or 20 to 60% by weight based on the weight of the molding material, more preferably 25 to 50% by weight. The molding material according to any one of claims 1 to 11, in the range of 25 to 50% by weight.

13. 1. A molding material for combining with one or more resin-free (dry) layers of fiber reinforcement and further combining with one or more pre-impregnated fiber reinforcement (prepreg) layers to form a laminate structure in a resin infusion process, comprising: a) a first nonwoven fibrous layer, the first nonwoven fibrous layer having an openness of 1 to 10%; b) a second nonwoven fibrous layer; and c) Resin layer Including, the resin layer bonds the second nonwoven fibrous layer to a first surface of the first nonwoven fibrous layer, and the resin layer is exposed on a second surface of the first nonwoven fibrous layer; When the molding material is combined with one or more resin-free (dry) layers of the fiber reinforcement, the second nonwoven fibrous layer is disposed between the first nonwoven fibrous layer and the one or more resin-free (dry) layers of the fiber reinforcement, and the second nonwoven fibrous layer is sewn onto the surface of the one or more resin-free (dry) layers of the fiber reinforcement; When the molding material is combined with one or more resin-free (dry) layers of the fiber reinforcement, the first nonwoven fabric fibrous layer is completely impregnated with the resin of the resin layer, the second nonwoven fabric fibrous layer is partially impregnated with the resin of the resin layer, and the one or more resin-free (dry) layers of the fiber reinforcement are not impregnated with the resin of the resin layer; A molding material, wherein the prepreg that is combined with the molding material to form a laminate structure in the resin infusion process has a resin content in the range of 30 to 45 wt % based on the weight of the prepreg material.

14. 1. A method for manufacturing a laminate structure, comprising: contacting the layer of resin exposed on the second surface of the first nonwoven fibrous layer with a surface of a mold or tool, and laying down the molding material according to any one of claims 1 to 12 on the surface of the mold or tool; applying one or more layers of resin-free (dry) fiber reinforcement to the opposing surface of said molding material to form a laminate; infusing the laminate with an infusion resin; and curing the injected laminate; A method comprising:

15. The molding material is the molding material of any one of claims 1 to 11, and the resin content of the molding material is in the range of 5 to 50% by weight, preferably 5 to 20% by weight, based on the weight of the molding material. The method according to claim 14.

16. 16. A method according to claim 14 or 15, wherein at least one layer of pre-impregnated fibre reinforcement (prepreg) is included in the laminate before infusion of resin.

17. 17. The method of claim 16, wherein the prepreg has a resin content in the range of 30 to 45 weight percent based on the weight of the prepreg material.

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