Molding materials

Abstract

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

Description

[0001] The present invention relates to a molding material, particularly but not exclusively to a molding material for surface application. Background Art

[0002] The present invention relates to a molding material providing an enhanced surface finish, the use of the molding material in combination with one or more pre-impregnated fiber reinforcement (prepreg) layers to form a laminate structure, the use of the molding material in combination with dry (unimpregnated) fiber layers to form a laminate structure, and a method of using the molding material to form a laminate structure. The invention particularly relates to a fiber-reinforced composite molding material that can be cured at low temperatures and includes a surface finishing layer to provide a molded article with a high-quality surface finish that requires minimal preparation after curing, particularly but not exclusively for use in the wind turbine and automotive industries.

[0003] Composite materials have well-documented advantages over traditional building materials, particularly in providing excellent mechanical properties at very low material density. As a result, the use of such composite materials has become widespread in many industries, including aerospace, automotive, marine, and wind turbines.

[0004] The prepreg that comprises the fiber arrangement thing of being impregnated by thermosetting resin such as epoxy resin is widely used in the production of this type of composite material.Typically, many such prepreg plies of " laying up " as required, and gained assembly thing or laminated material are placed in mould and solidify, usually by being exposed to the temperature of raising, optionally under pressure, to produce the composite laminated material of solidification.In alternative manufacturing technology, usually lay up fibrous material in enclosure, in enclosure, pour liquid resin system with encapsulation fibrous material, it can then solidify to produce finished product therein.Can complete sealing around fibrous material and suck resin (sometimes referred to as vacuum bag technology) under vacuum.Alternatively, enclosure can be mould, and resin can be injected into mould (sometimes referred to as resin transfer moulding (Resin Transfer Moulding)), it can also be vacuum-assisted (being referred to as vacuum-assisted resin transfer moulding (Vacuum Assisted Resin Transfer Moulding)). As with the systems described previously in relation to prepregs, the liquid resin system may be an epoxy, cyanate ester or bismaleimide resin and it will also contain a curing agent for the particular resin.

[0005] However, without any surface treatment, composite materials produced by any of the above techniques typically cure to produce a poor surface finish, which can manifest itself as a rough, wavy, or pinhole-filled surface or as narrow grooves on the surface of a molded structure where adjacent prepreg plies have overlapped to ensure a continuous layer. This tendency to form an uneven surface appears to be closely related to the roughness of the underlying reinforcement, with the rougher the reinforcement, the more pronounced the problem. This can be particularly problematic when rough reinforcement is used for structural stiffness and a smooth surface finish is desired (such as, for example, in the production of automotive body panels, where a Class A finish is required, or in the production of wind turbine blades).

[0006] GB 2445929 discloses a fiber-reinforced composite molded article comprising a surface portion laminated to a structural portion, the surface portion being formed by a surface layer comprising a plurality of surface layer segments, the plurality of surface layer segments being molded together to form a continuous surface layer, the surface layer comprising a first cured resin material supported on a sheet material carrier, and the structural portion being formed by at least one fiber reinforcement layer and a cured second resin material, the at least one fiber reinforcement layer being formed by a plurality of segments, each segment covering a corresponding surface layer segment, and each surface layer segment overlapping an adjacent segment of the fiber reinforcement.

[0007] We found that such molded parts still had poor surface quality, as print-through of the underlying carrier material and fiber reinforcement was evident. Furthermore, the layup required overlapping, which in turn led to surface defects in the form of visible weld lines.

[0008] WO 2008 / 007094 in Figure 2 A surface material is disclosed, comprising a surface layer and a flannel layer, the surface layer comprising a resin layer and a face veil. The resin layer is brought into contact with a mould surface and the face veil is adhered thereto. The flannel contains resin strips which promote adhesion of the flannel layer to the face veil, so that the flannel layer is only partially impregnated with resin. This material has the problem of a low resin content in the surface layer, which requires any subsequent prepreg layer to have an increased resin content. This means that prepreg materials having a resin content significantly higher than usual (typically exceeding 60% by weight) can be used solely in combination with this surface material, which is complex, inefficient and costly. Furthermore, the manufacture of the flannel layer with the resin strips is complex and therefore inefficient and costly, because conventionally, the reinforcing layer is impregnated over its entire surface.

[0009] WO 2017 / 021147 in Figure 2A surface material is disclosed, comprising a surface layer comprising a resin layer sandwiched between a face veil and a fleece layer. The face veil layer contacts the mold surface, and the face veil and fleece layers are adhered to the resin layer such that they are substantially unimpregnated. This facilitates the release of any trapped air in the layup near the mold surface. However, this material still suffers from the low resin content of the surface layer, requiring any subsequent prepreg layers to have an increased resin content, which is complex, inefficient, and costly.

[0010] The present invention aims to obviate or at least alleviate the above-mentioned problems and / or generally provide improvements.

[0011] manual

[0012] According to the present invention, there is provided a molding material, preferably a surface material, as claimed in any one of the appended claims; the use of the molding material and a method for producing a laminate structure.

[0013] The present invention provides a molding material, comprising:

[0014] a) a main nonwoven fiber layer;

[0015] b) a secondary nonwoven fibrous layer; and

[0016] c) resin layer;

[0017] The resin layer bonds the secondary nonwoven fiber layer to the first surface of the primary nonwoven fiber layer, and the resin layer is exposed on the second surface of the primary nonwoven layer.

[0018] Surprisingly, we have now found that combining a resin layer exposed on the surface of the molding material of the present invention with a nonwoven fiber layer provides excellent surface quality without pinholes. We have also found that, through the construction of the molding material of the present invention, appearance defects due to print-through of the carbon fiber reinforcement layer are avoided.

[0019] The materials of the present invention also provide excellent surface finish when used as mold or tool contact layers when pre-impregnated reinforcements and / or unimpregnated reinforcements are used in prepreg or infusion systems to prepare laminate products.

[0020] Furthermore, we have found that prepreg reinforcement layers can be used with this material having a resin content of between 30% and 45% by weight of the prepreg without any adverse effect on the surface quality. This allows standard prepreg materials to be used in combination with this moulding material without the need for increased resin content.

[0021] In a particular aspect of the present invention, the molding material of the present invention can be provided as a surface finishing layer, i.e. without any reinforcement layer, and thus in this aspect, the molding material can essentially consist of a primary nonwoven fiber layer, a secondary nonwoven fiber layer and a resin layer. In an alternative aspect, the molding material can be provided as a reinforced surface finishing layer, and in this aspect, the molding material can include a reinforcement layer, wherein the secondary nonwoven layer is located between the primary nonwoven fiber layer and the reinforcement layer. DETAILED DESCRIPTION

[0022] Specific embodiments of the present invention will now be described in more detail below by way of examples.

[0023] In the molding material of the present invention, the resin layer bonds the secondary non-woven fiber layer to the first surface of the primary non-woven fiber layer, and the resin layer is exposed on the second surface of the primary non-woven fiber layer, and therefore, the primary non-woven fiber layer is generally completely saturated with the resin layer. In addition, in certain embodiments, the secondary non-woven fiber layer is at least partially impregnated with the resin of the resin layer and optionally completely impregnated with the resin of the resin layer.

[0024] In a particular embodiment of the present invention, the resin layer comprises a formulated resin matrix comprising at least one resin component, at least one curing agent, and optionally a filler.

[0025] The resin matrix forming the preparation of resin layer can comprise thermosetting resin, such as polyester resin, polyurethane resin, polyurethane / polyurea resin, phenol-formaldehyde resin, urea-formaldehyde resin, vinyl ester resin, cyanate ester resin, polyimide resin or epoxy resin.Unlike thermoplastic resin, thermosetting resin becomes irreversibly hardened when solidifying, makes any molding produced by it all anti-deformation.In one embodiment, the first resin composition is a thermosetting resin composition, preferably epoxy resin composition, i.e. comprises epoxy resin or epoxy resin blend.

[0026] The resin layer preferably comprises at least one multifunctional bisphenol epoxy resin material in combination with a urea based curing agent.A preferred formulated resin matrix for this layer is M79 resin such as that supplied by Hexcel Corporation.

[0027] In another embodiment of the present invention, the formulated resin matrix comprises between 1% and 10% by weight of a filler, preferably a silica filler or an organophilic layered silicate, preferably a fumed silica filler having a tap density of 60 g / l, based on the weight of the formulated resin matrix. A preferred filler material is Aerosil R202, such as supplied by Evonik Industries.

[0028] We have found that the inclusion of fillers reduces the flow of the resin layer, which is beneficial in layups involving a large number of vertical surfaces, such as in the manufacture of boat and yacht hulls.

[0029] The primary and secondary nonwoven fibrous layers of the present invention preferably have the following properties and characteristics. The nonwoven fibrous layers may comprise any nonwoven material that is permeable to both air and resin. Suitable nonwoven fibrous carriers are heavyweight, preferably less than 100 g / m 2 , but preferably is robust enough to carry a resin layer and withstand the handling during layup and processing to form a composite part with a high quality appearance surface.

[0030] The nonwoven fibrous layer may comprise continuous fibers or discontinuous fibers.

[0031] In one embodiment, the primary nonwoven layer comprises a face veil. In the context of the present invention, the term "face veil" refers to a thin, heavyweight (i.e., having an area weight not exceeding 100 g / m 2 ), porous, nonwoven, mesh or fiber reinforcement.

[0032] In preferred embodiments, the primary nonwoven layer is typically composed of nonwoven fibers of a thermoplastic material, preferably wherein an organic binder is used to bind the fibers together to impart structural integrity to the material. In a particular embodiment, the thermoplastic material comprises a polyester; a polyamide, preferably an aliphatic or semi-aromatic polyamide; and / or a combination of polyesters and polyamides. If present, the organic binder is typically present in an amount of 1% to 10% by weight, based on the total weight of the primary nonwoven layer.

[0033] The purpose of the primary nonwoven layer is to act as a support or carrier for the resin layer, to retain the resin on the outer surface and to control the way the resin interacts with the mold or tool surface in order to provide a good surface finish.

[0034] In one embodiment, the primary nonwoven material has an openness between 1% and 10%, preferably 2% to 89%, and / or a thickness between 75 and 350 μm. 2 The average open area between.

[0035] In a further embodiment, the primary nonwoven fibrous layer has a fiber content of from 1 to 80 g / m 2 , preferably from 5 to 50 g / m 2 , more preferably from 15 to 40 g / m 2 Area weight within the range.

[0036] In one embodiment, the primary nonwoven fibrous layer has an air permeability of about 2,300 L / m2 / s at an applied pressure of 200 Pa (as measured according to ASTM D737-18). Suitable thermoplastic fiber materials in veil form that can be used as the primary nonwoven fibrous layer include those available from Technical Fibre Products Limited of Burnside Mills, Kendal, Cumbria, United Kingdom under the trade name Commercially available ones, such as Optiveil T2761-00.

[0037] Openness measurements can be made using a Keyence VHX-6000 series digital microscope manufactured by Keyence (UK) Limited of Milton Keynes, Buckinghamshire, United Kingdom. The nonwoven material can be presented to the microscope by mounting it on a blue plastic card to help highlight the open area when viewed on a computer monitor. The microscope was set to 175x magnification, the light output was set to maximum, and the gain dial setting was adjusted so that the open area could be clearly identified. The saved computer image showed a total area of 2951002 μm2.

[0038] Then use Keyence software to measure average " open area " (that is, the empty space between fibers) and openness%. Also manipulate the image by adjusting the slider on the histogram to create a two-color image, where one color represents fiber and the other represents open space. Then use software to measure the area of all individual open spaces. This data can be saved in a spreadsheet and used to calculate the total area occupied by open space (to calculate openness%) and the average size of the open area.

[0039] The secondary nonwoven fiber layer can comprise a nonwoven fiber material containing continuous fibers or discontinuous fibers. The secondary nonwoven fiber material can comprise nonwoven fibers of glass, carbon, polyester, polyamide, aramid (aromatic polyamide) or a combination thereof, which are optionally bound together using an organic binder to impart structural integrity to the material. Preferably, the secondary nonwoven fiber layer comprises a glass fiber material, or a polyester material or a polyolefin polymer material and / or a combination of the foregoing materials.

[0040] Preferably, the secondary nonwoven fiber carrier comprises a nonwoven glass fiber material in the form of a veil. If present, the organic binder may typically be present in an amount of 1% to 10% by weight based on the total weight of the second nonwoven fiber carrier. Typically, the area weight or surface density of the secondary nonwoven fiber material will be slightly higher than that of the primary nonwoven fiber layer. In a preferred embodiment, the secondary nonwoven fiber has a surface density of from 20 to 100 g / m 2 In the range of from 30 to 80 g / m2 In the range of from 30 to 60 g / m 2 Suitable nonwoven glass veils, mats or fleeces are available from Johns Manville in Denver, Colorado, USA under the trade name Commercial purchases, including but not limited to ST-3022, S 4030 and S 5030, and are available from Taishan Fiberglass Inc., Taian Economic Development Zone, Shandong Province, China under the trade name Commercial purchases, including but not limited to S-SM30, S-SM50, S-HM30 and S-HM50.

[0041] The presence of the second nonwoven fiber material helps prevent the fiber reinforcement in the structural reinforcement layer from "printing through" and appearing on the surface of the molded material after curing, and also ensures that sufficient second resin composition remains within the surface reinforcement layer during the curing process, thereby avoiding the formation of narrow grooves or other surface irregularities due to resin starvation. Like the first nonwoven fiber material, the second nonwoven fiber material can also be used to prevent air entrapment or help dissipate trapped air.

[0042] In one particular aspect of the present invention, the molding material does not contain any reinforcing material, and therefore, the molding material consists essentially of the primary nonwoven fiber layer, the secondary nonwoven fiber layer, and the resin layer.

[0043] In an embodiment of the invention according to the first aspect in which there is no reinforcement, the total resin content of the molding material may be contained in the resin associated with the primary nonwoven layer. The preferred total resin content of the molding material of this embodiment will depend on the intended use of the molding material, but preferably, the resin content of the molding material is in the range of from 40 to 75 wt % based on the weight of the molding material, more preferably from 50 to 60 wt % based on the weight of the molding material.

[0044] In a second aspect of the present invention, the molding material of the present invention comprises a reinforcement layer, wherein the secondary nonwoven fiber layer is located between the primary nonwoven fiber layer and the reinforcement layer. The presence of the reinforcement layer helps to improve the structural integrity of the molding material, which is convenient for storage, transportation and handling.

[0045] Preferably, the secondary nonwoven fiber layer is sewn to the surface of the reinforcement layer.The layers may be sewn with polyester yarn having a tex value ranging from 5 to 90 dtex, preferably from 40 to 85 dtex and more preferably from 70 to 85 dtex.

[0046] The structural reinforcement layer may take many forms. Typically, the moulding material according to the second aspect of the invention will contain several structural reinforcement layers, although for some applications a single layer may be sufficient.

[0047] The fiber reinforcement material can be in the form of a sheet or a continuous mat or continuous filament. In other embodiments, the fiber reinforcement material comprises short length fibers, such as chopped strand mats. The fiber reinforcement material can be in the form of multiple fiber tows, each fiber tow containing multiple fiber filaments to form each tow. The tows can be sewn or woven to form a fabric. The fiber can be composed of: natural materials, such as cotton, flax, hemp, wool or silk; or semi-synthetic materials, such as rayon, viscose, modal, etc.; or synthetic materials, such as carbon, polyester, mineral, nylon, acrylic, glass, aramid (aramid), etc. In a preferred embodiment, the fiber reinforcement comprises carbon fiber or glass fiber.

[0048] In some embodiments, the fiber reinforcement material is in the form of a woven fabric. In other embodiments, the fiber reinforcement material comprises a unidirectional (UD) fabric, in which most of the fibers, rovings or tows present in the fabric extend in only one direction, although a few fibers, rovings or tows may extend in a direction different from the majority, for example as a cross stitch, in order to maintain the unidirectional alignment of the latter. The fibers, rovings or tows in the unidirectional fabric can be kept aligned by a variety of different methods, including weaving, stitching and combining. Therefore, such unidirectional fabrics can be woven or non-woven. In further embodiments, the fiber reinforcement material comprises a combination of a unidirectional fabric and a biaxial or multiaxial fabric or mat, in which any component can be woven or non-woven.

[0049] Suitable woven and nonwoven fabrics for composite materials are commercially available from specialist manufacturers including, but not limited to, Chomarat Textiles Industries of Esher, Surrey, UK, Hexcel Reinforcements UK Limited of Narborough, Leicestershire, UK, and Zhenshi Group Hengshi Fibreglass Fabrics Co., Ltd. of Tongxiang Economic Development Zone, Jiaxing City, Zhejiang Province, China 314500. In one embodiment, the woven or nonwoven fabric is a carbon fiber or glass fiber fabric such as BB200, BB600 or BB1200, where, for example, the designation BB1200 refers to a fiber having a fiber weight of 1200 g / m 2 The area weight of biaxial glass fabric is .

[0050] Hybrid or mixed fiber systems are also conceivable.The use of broken (ie stretch-broken) or selectively discontinuous fibers may be advantageous in facilitating the layup of the molding material according to the invention and improving its formability.

[0051] The area weight of fiber reinforcement is usually from 40 to 4,000 g / m 2 In a preferred embodiment, the fiber area weight is preferably in the range of 100 to 2,500 g / m 2 , more preferably 150 to 2,000 g / m 2 within the range.

[0052] The fibre reinforcement in the structural reinforcement layer or layers where more than one is present will typically be a heavyweight non-crimped fabric such as a glass fabric. For glass reinforcement, fibres of 68 to 2400 tex (g / km yarn) are particularly suitable.

[0053] In a particular embodiment of the second aspect of the present invention, the reinforcement layer may comprise at least two layers, each layer comprising unidirectional fibers. The unidirectional fibers of each layer may be in different directions.

[0054] In one embodiment, the unidirectional fiber layer and the secondary nonwoven fiber layer are optionally stitched together using the same stitching yarn.

[0055] The reinforcement layer preferably comprises a fiber reinforcement material and a formulated reinforcing resin matrix, and in a preferred embodiment, the formulated reinforcing resin matrix has the same composition as the resin of the resin layer.

[0056] In an embodiment of the present invention according to the second aspect, in which a reinforcement layer is present, the total resin content of the molding material can be contained in the resin associated with the primary nonwoven layer, or the resin can be distributed throughout the material as a plurality of discrete layers or as a single matrix throughout the material. The preferred total resin content of the molding material of this embodiment will depend on the intended use of the molding material and also the weight of the reinforcement layer, but preferably, the resin content of the molding material is in the range of from 5 to 60 wt % based on the weight of the molding material. For example, in a molding material intended for use in an infusion system, the total resin content is preferably from 5 to 50 wt %, more preferably from 5 to 20 wt %, and similarly, for a molding material intended to be used in combination with at least a portion of a prepreg material without infusion, the total resin content is preferably from 20 to 60 wt %, more preferably from 25 to 50 wt %.

[0057] The invention further provides the use of the inventive moulding material in combination with one or more pre-impregnated fibre reinforcement (prepreg) layers to form a laminate structure, the prepreg layers having a resin content in the range from 30% to 45% based on the weight of the prepreg material.

[0058] The present invention further provides the use of a moulding material according to the invention in combination with one or more resin-free (dry) fibre reinforcement layers to form a laminate structure in a resin infusion process.

[0059] The present invention also provides a method of making a laminate structure, the method comprising laying down a molding material according to the present invention on the surface of a mold or tool, wherein the resin layer exposed on the second surface of the primary nonwoven fiber layer is in contact with the tool or mold surface;

[0060] applying one or more resin-free (dry) fiber reinforcement layers to opposing surfaces of the molding material to form a stack;

[0061] infusing the stack with infusing resin, and

[0062] The infused stack is cured.

[0063] In the method for producing the laminate structure of the present invention, the molding material used in the method may be the molding material according to the first aspect of the present invention, i.e., a molding material not comprising a reinforcement layer. Alternatively, the molding material may be the molding material according to the second aspect of the present invention, i.e., a molding material comprising a reinforcement layer, and in particular a molding material comprising a reinforcement layer and wherein the resin content of the molding material is in the range of from 5 to 50% by weight, preferably in the range of from 5 to 20% by weight, based on the weight of the molding material.

[0064] In the method of manufacturing a laminate structure according to the invention, at least one pre-impregnated fiber reinforcement (prepreg) layer may be included in the stack prior to infusion with resin.

[0065] In the method of manufacturing a laminate structure according to the invention, any conventional infusion process and infusion resin may be used, depending on the intended use of the laminate structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The present invention will now be described, by way of example only, and with reference to the accompanying drawings.

[0067] Figure 1 A diagrammatic view of a molding material according to one embodiment of the present invention is presented, and

[0068] Figure 2 A diagrammatic view of another molding material according to another embodiment of the present invention is presented.

[0069] exist Figure 1 , a molding material 100 is shown, which includes a primary nonwoven fiber layer 102 and a secondary nonwoven fiber layer 104.

[0070] The primary nonwoven fibrous layer 102 contains a resin layer 106 exposed on its surface but extending throughout the primary nonwoven fibrous layer 102 and at least contacting and optionally extending partially or completely into the secondary nonwoven fibrous layer 104 .

[0071] The primary and secondary nonwoven fiber layers 102 , 104 are bonded by gluing with a resin layer 106 .

[0072] In one particular embodiment, the primary nonwoven layer 102 is a nonwoven thermoplastic face veil comprising a blend of polyamide and polyester materials having a 15 g / m 2 The weight of the resin layer 106 has 65g / m 2 The weight of the secondary nonwoven fiber layer 104 is 50g / m 2 The weight of the fiberglass material flannel.

[0073] In typical applications, the molding material 100 is positioned to contact the mold surface, and the upper surface of the resin layer 106 contacts the mold. An additional at least partially pre-impregnated reinforcing layer of resin may be positioned on the top of the molding material 100, promptly contacted with the secondary nonwoven layer 104 to build the composite layup, which is then subsequently cured to produce a composite part. In alternative applications, the molding material 100 is positioned to contact the tool surface, wherein the upper surface of the resin layer 106 contacts the tool. An additional non-impregnated (i.e., dry) reinforcing layer may be positioned on the top of the molding material 100, promptly contacted with the secondary nonwoven layer 104 to build the composite layup, which is then infused with resin and cured to produce a composite part.

[0074] exist Figure 2 , a molding material 200 is shown, which includes a primary nonwoven fiber layer 202 and a secondary nonwoven fiber layer 204. The primary nonwoven fiber 202 layer contains a resin layer 206, which is exposed on its surface and extends throughout the primary nonwoven fiber layer 202 and at least contacts and optionally partially or completely extends into the secondary nonwoven fiber layer 204. A fiber reinforcement layer 208 is located on the opposite surface of the secondary nonwoven layer 204. The primary nonwoven fiber layer and the secondary nonwoven fiber layer 202, 204 are bonded by gluing the resin layer 206, and the secondary nonwoven fiber layer 204 and the reinforcement layer 208 are bonded by sewing. This allows the reinforcement layer 208 to remain unimpregnated (dry) with resin.

[0075] In one particular embodiment, the resin composition contains a bifunctional epoxy resin in combination with a urea-based curing agent; the primary nonwoven fiber layer 202 is a 15 g / m 2 The weight of the non-manufactured polyester veil; the resin layer 206 has 140g / m 2 The weight of the secondary nonwoven fiber layer 204 is 50g / m 2 Weight of fiberglass fleece.

[0076] In a preferred embodiment, the reinforcement layer 208 is preferably in the form of two unidirectional fiber layers that combine to form a biaxial layer, preferably having an orientation of + / - 45 degrees.

[0077] In typical applications, the molding material 200 is positioned in contact with the mold surface, and the upper surface of the resin layer 206 is in contact with the mold. Additional reinforcement layers are positioned on top of the molding material 200 to build a composite layup, which is then subsequently cured to produce a composite part. In alternative applications, the molding material 200 is positioned in contact with the tool surface, with the upper surface of the resin layer 206 in contact with the tool. Additional unimpregnated (i.e., dry) reinforcement layers may be positioned on top of the molding material 200, i.e., in contact with the secondary nonwoven layer 204 to build a composite layup, which is then infused with resin and cured to produce a composite part.

[0078] Thus, there is provided a moulding material which can be used in combination with pre-impregnated fibre reinforcement (prepreg) layers having a resin content in the range from 30% to 45% by weight based on the weight of the prepreg, and which can also be used in combination with unimpregnated fibre reinforcement layers to form a laminate in an infusion system.

[0079] Example

[0080] Example 1

[0081] A resin composition (Composition 1) was prepared as follows:

[0082] 72.9 g Kukdo KFR136SL, a semisolid bisphenol A diglycidyl ether epoxy resin manufactured by Kukdo Chemical Company Limited, Seoul, South Korea);

[0083] 18.2g 828 (liquid bisphenol A diglycidyl ether epoxy resin manufactured by Hexion Inc., Columbus, Ohio, USA);

[0084] 2.9g UR500 (a difunctional latent urone accelerator in powder form manufactured by Alzchem Group AG, Trostberg, Germany).

[0085] The components are mixed thoroughly at a temperature of 50°C to 60°C until the mixture has a uniform consistency.

[0086] Construct a molding material with the following architecture:

[0087] (1) First floor S 5030 (made by Johns Manville, Denver, Colorado, USA with a 50 g / m 2 areal weight of glass fiber fleece);

[0088] (2) A lightweight, fully synthetic nonwoven fiber veil layer comprising a blend of polyester and polyamide fibers having a 15 g / m 2 areal weight of (manufactured by Technical Fibre Products Limited, Browns Mills, Kendal, Cumbria, United Kingdom); and

[0089] (3)65g / m 2 1 layer of the resin composition.

[0090] The assembled layers were consolidated by passing them through an S-wrap roller system heated to 80°C to form a layer corresponding to Figure 1 The molding material 100 is shown in FIG.

[0091] The composite part is produced by placing the molding material 100 on a Watershield TM The composite tool was treated with a silicone-free water-soluble 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-crimped glass fabric) and 1 layer of Bleeder Lease B (62 g / m 2 The fabric was silicone treated nylon fabric) and infused with Hexion RIM R135 / RIM H 137 (a liquid epoxy resin and hardener combination from Hexion Inc., Columbus, Ohio, USA) and then cured at 80°C under 1 bar pressure for 6 hours.

[0092] After cooling, the cured molded parts are removed for inspection and further testing.

[0093] Example 2

[0094] A resin composition (composition 2) was prepared from the same components as in composition 1, but with the addition of 6 g of R202 (a hydrophobic fumed silica rheology modifier manufactured by Evonik Resource Efficiency GmbH, Hanau-Wolfgang, Germany.

[0095] The components are mixed thoroughly at a temperature of 50°C to 60°C until the mixture has a uniform consistency.

[0096] Construct a molding material with the following architecture:

[0097] (1) One layer of LBB1200 fabric (1250 g / m2 manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, United Kingdom) 2 triaxial non-crimped glass fabric);

[0098] (2) First floor S 5030 (made by Johns Manville, Denver, Colorado, USA with a 50 g / m 2 areal weight of glass fiber fleece);

[0099] (3) A lightweight, fully synthetic nonwoven fiber veil layer comprising a blend of polyester and polyamide fibers having a 15 g / m 2 areal weight of (manufactured by Technical Fibre Products Limited, Browns Mills, Kendal, Cumbria, United Kingdom); and

[0100] (4)140g / m 2 2 layers of the resin composition.

[0101] The assembled layers were consolidated by passing them through an S-wrap roller system heated to 80°C to form a layer corresponding to Figure 2 The molding material 200 is shown in FIG.

[0102] The composite part is produced by placing the molding material 1 on the Watershield TMThe composite tool was treated with a silicone-free water-soluble 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-crimped glass fabric) and 1 layer of Bleeder Lease B (62 g / m 2 The fabric was silicone treated nylon fabric) and infused with Hexion RIM R135 / RIM H 137 (a liquid epoxy resin and hardener combination from Hexion Inc., Columbus, Ohio, USA) and then cured at 80°C under 1 bar pressure for 6 hours.

[0103] After cooling, the cured molded parts are removed for inspection and further testing.

[0104] Example 3

[0105] Resin composition 2 was used to form a molding material having the following structure:

[0106] (1)400g / m 2 2 layers of a resin composition;

[0107] (2) One layer of LBB1200 fabric (1250 g / m2 manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, United Kingdom) 2 triaxial non-crimped glass fabric);

[0108] (3) First floor S 5030 (made by Johns Manville, Denver, Colorado, USA with a 50 g / m 2 areal weight of glass fiber fleece);

[0109] (4) A lightweight, fully synthetic nonwoven fiber veil layer comprising a blend of polyester and polyamide fibers having a 15 g / m 2 areal weight, manufactured by Technical Fiber Products Limited, Browns Mills, Kendal, Cumbria, United Kingdom); and

[0110] (5)400g / m 2 2 layers of the resin composition.

[0111] The assembled layers were consolidated by passing them through an S-wrap roller system heated to 80°C to form a layer corresponding to Figure 2 The molding material 200 is shown in FIG.

[0112] The molding material 200 is placed on the Watershield TM (a silicone-free water-soluble mold release agent manufactured by Freeman Manufacturing and Supply Company of Avon, Ohio, USA) in a composite tool wherein the resin composition layer (5) is adjacent to the face of the mold. 79 (a prepreg manufactured by Hexcel GmbH, Neumarkt, Germany) was placed on top of the molding material in the mold, i.e., next to the resin layer (1); and the assembly was 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.

Claims

1. A method of manufacturing a laminate structure, the method comprising: Laying a molding material on a surface of a mold or tool, wherein the molding material comprises: a) a main nonwoven fibrous layer having an upper surface and a lower surface, the main nonwoven fibrous layer comprising polyester or aliphatic or semi-aromatic polyamide fiber material having a fiber density of 10 to 40 g / m 2 The main nonwoven fiber layer has an openness between 1% and 10% and an area weight of 75μm. 2 Up to 350μm 2 an average open area between the primary nonwoven fibrous layer and the primary nonwoven fibrous layer, the primary nonwoven fibrous layer being completely saturated with resin, wherein the primary nonwoven fibrous layer has an air permeability of 2,300 L / m2 / s under an applied pressure of 200 Pa as measured in accordance with ASTM D737-18; b) a secondary nonwoven fibrous layer having an upper surface and a lower surface, the secondary nonwoven fibrous layer comprising a glass fiber material, a polyolefin polymer material, or a combination thereof and having a 30 g / m 2 Up to 60g / m 2 Area weight; c) a fiber reinforcement layer having an upper surface and a lower surface, the lower surface of the fiber reinforcement layer being sewn to the upper surface of the secondary non-woven fiber layer, whereby the fiber reinforcement layer remains substantially unimpregnated with resin, the reinforcement layer comprising at least two unidirectional fiber layers, each unidirectional fiber layer being arranged in a different direction, the layers of the reinforcement layer being sewn together, wherein the fibers of each unidirectional fiber layer of the reinforcement layer have a tex of 68 to 2400; and d) a resin layer comprising at least one resin component, at least one curing agent, and at least one silica filler, wherein the resin layer is bonded to a lower surface of the primary nonwoven fibrous layer and a lower surface of the secondary nonwoven fibrous layer is bonded to an upper surface of the primary nonwoven fibrous layer, and wherein the resin layer at least partially impregnates the primary nonwoven fibrous layer and partially impregnates the secondary nonwoven fibrous layer, whereby the molding material comprises 25-50% by weight of resin; wherein the resin layer bonds the secondary nonwoven fiber layer to the upper surface of the primary nonwoven fiber layer, and the resin layer is exposed on the lower surface of the primary nonwoven fiber layer, whereby the molding material provides excellent surface quality with substantially no pinholes and substantially no print-through when solidified, wherein the resin layer exposed on the lower surface of the primary nonwoven fiber layer is in contact with a tool or mold surface; applying one or more resin-free fiber reinforcement layers to opposing surfaces of the molding material to form a stack; infusing the stack with infusing resin, and The poured stack is cured.

2. The method of claim 1, wherein the stack comprises at least one pre-impregnated fiber reinforcement layer prior to infusion with the resin.

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