MOULDING MATERIAL

Abstract

The present invention is concerned with a moulding material comprising: a) A primary non-woven fibre layer; b) A secondary non-woven fibre layer, and c) A resin layer; wherein the resin layer bonds the secondary non-woven fibre layer to a first surface of the primary non-woven fibre layer, and the resin layer is exposed on the second surface of the primary non-woven layer.

Claims

1. A moulding material comprising: a) a primary non-woven fibre layer, said primary non-woven fibre layer having an upper and a lower face, said primary non-woven layer comprising a polyester or an aliphatic or semi-aromatic polyamide fibre material, having an areal weight of 10 to 40 g/m.sup.2; b) a secondary non-woven fibre layer, said secondary non-woven fibre layer having an upper and a lower face, said secondary non-woven fibre layer comprising glass fibre material, polyolefin polymer material, or a combination of said materials, and having an areal weight of 30 to 60 g/m.sup.2; and c) a resin layer, said resin layer comprising at least one resin component, at least one curative and at least one silica filler; wherein said resin layer is conjoined to the lower face of said primary non-woven fibre layer and the lower face of said secondary non-woven fibre layer is conjoined to the upper face of said primary non-woven fibre layer; and wherein said resin layer impregnates at least partially id primary non-woven fibre layer and partially impregnates said secondary non-woven fibre layer; whereby said moulding material comprises 25 to 50% by weight resin; wherein the resin layer bonds the secondary non-woven fibre layer to the upper surface of the primary non-woven fibre layer, and the resin layer is exposed on the lower surface of the primary non-woven layer.

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. (canceled)

11. (canceled)

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. (canceled)

20. The method of manufacturing a laminate structure, the method comprising laying down a moulding material according to claim 1 on the surface of a mould or tool with the layer of resin exposed on the lower surface of the primary non-woven fibre layer in contact with tool or mould surface; applying one or more layers of resin-free (dry) fibrous reinforcement to the opposite surface of the moulding material to form a stack; infusing the stack with an infusion resin, and curing the infused stack.

21. (canceled)

22. (canceled)

23. The method of claim 20, wherein at least one layer of preimpregnated fibrous reinforcement (prepreg) is included in the stack before infusion with the resin.

24. A moulding material comprising: a) a primary non-woven fibre layer, said primary non-woven fibre layer having an upper and a lower face, said primary non-woven layer comprising a polyester or an aliphatic or semi-aromatic polyamide fibre material, having an areal weight of 10 to 40 g/m.sup.2; b) a secondary non-woven fibre layer, said secondary non-woven fibre layer having an upper and a lower face, said secondary non-woven fibre layer comprising glass fibre material, polyolefin polymer material, or a combination of said materials, and having an areal weight of 30 to 60 g/m.sup.2; c) a fibrous reinforcement layer, said fibrous reinforcement layer having a upper and lower face; the lower face of said fibrous reinforcement layer being stitched to the upper surface of the secondary fibre layer; said reinforcement layer comprising at least two layers of unidirectional fibres, each layer of unidirectional fibres being disposed in different directions; said layers of said reinforcement layer being stitched together; and d) a resin layer, said resin layer comprising at least one resin component, at least one curative and at least one silica filler; wherein said resin layer is conjoined to the lower face of said primary non-woven fibre layer and the lower face of said secondary non-woven fibre layer is conjoined to the upper face of said primary non-woven fibre layer; and wherein said resin layer impregnates at least partially said primary non-woven fibre layer and partially impregnates said secondary non-woven fibre layer; whereby said moulding material comprises 25 to 50% by weight resin; wherein the resin layer bonds the secondary non-woven fibre layer to the upper surface of the primary non-woven fibre layer, and the resin layer is exposed on the lower surface of the primary non-woven layer.

25. The moulding material of claim 24, wherein the fibres of said layers of unidirectional fibres of said reinforcement layer are of 68 to 2400 tex.

Description

DRAWINGS

[0064] The invention will now be described by way of example only and with reference to the accompanying drawings.

[0065] FIG. 1 presents a diagrammatic view of a moulding material according an embodiment of the present invention, and;

[0066] FIG. 2 presents a diagrammatic view of another moulding material according to another embodiment of the invention.

[0067] In FIG. 1 a moulding material 100 is shown which comprises a primary non-woven fibre layer 102 and a secondary non-woven fibre layer 104. The primary non-woven fibre layer 102 contains a resin layer 106 which is exposed on its surface but extends throughout the primary non-woven fibre layer 102 and at least contacts, and optionally extends partially or fully into, the secondary non-woven fibre layer 104. The primary and secondary non-woven fibre layers 102, 104 are bonded by the tack of the resin layer 106.

[0068] In a particular embodiment, the primary non-woven layer 102 is a non-woven thermoplastic veil containing a blend of polyamide and polyester material having a weight of 15 g/m.sup.2; the resin layer 106 has a weight of 65 g/m.sup.2, and the secondary non-woven fibre layer 104 is a glass fibre material fleece having a weight of 50 g/m.sup.2.

[0069] In a typical use, the moulding material 100 is located in contact with a mould surface with the upper surface of the resin layer 106 in contact with the mould. Additional at least partially resin preimpregnated reinforcement layers may be located on top of the moulding material 100, i.e. in contact with the secondary non-woven layer 104 to build a composite lay-up which is then subsequently cured to produce a composite part. In an alternative use, the moulding material 100 is located in contact with a tool surface with the upper surface of the resin layer 106 in contact with the tool. Additional unimpregnated (i.e. dry) reinforcement layers may be located on top of the moulding material 100, i.e. in contact with the secondary non-woven layer 104 to build a composite lay-up which is then subsequently infused with resin and cured to produce a composite part.

[0070] In FIG. 2 a moulding material 200 is shown which comprises a primary non-woven fibre layer 202 and a secondary non-woven fibre layer 204. The primary non-woven fibre 202 layer contains a resin layer 206 which is exposed on its surface and extends throughout the primary non-woven fibre layer 202 and at least contacts, and optionally extends partially or fully into, the secondary non-woven fibre layer 204. A fibrous reinforcement layer 208 is located on the opposite surface of the secondary non-woven layer 204. The primary and secondary non-woven fibre layers 202, 204 are bonded by the tack of the resin layer 206, and the secondary non-woven fibre layer 204 and the reinforcement layer 208 are bonded by stitching. This allows the reinforcement layer 208 to remain unimpregnated with resin (dry).

[0071] In a particular embodiment, the resin composition contains a difunctional epoxy in combination with a urea-based curative; the primary non-woven fibre layer 202 is a non-woven polyester veil having a weight of 15 g/m.sup.2; the resin layer 206 has a weight of 140 g/m.sup.2, and the secondary non-woven fibre layer 204 is a glass fibre fleece having a weight of 50 g/m.sup.2.

[0072] In a preferred embodiment, the reinforcement layer 208 is preferably in the form of two layers of unidirectional fibre combined to form a biaxial layer, preferably having an orientation +/−45 degrees.

[0073] In typical use, the moulding material 200 is located in contact with a mould surface with the upper surface of the resin layer 206 in contact with the mould. Additional reinforcement layers are located on top of the moulding material 200 to build a composite lay-up, which is then subsequently cured to produce a composite part. In an alternative use, the moulding material 200 is located in contact with a 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 located on top of the moulding material 200, i.e. in contact with the secondary non-woven layer 204 to build a composite lay-up which is then subsequently infused with resin and cured to produce a composite part

[0074] There is thus provided a moulding material which can be used in combination with preimpregnated fibrous reinforcement (prepreg) layers which have a resin content in the range of from 30% to 45% by weight based on the weight of the prepreg, and which can also be used in combination with unimpregnated fibrous reinforcement layers to form a laminate in an infusion system.

EXAMPLES

Example 1

[0075] A resin composition (composition 1) was formulated from:

[0076] 72.9 g Kukdo KFR136SL, a semi-solid bisphenol A diglycidyl ether epoxy resin manufactured by Kukdo Chemical Company Limited, Seoul, Korea);

[0077] 18.2 g Epikote® 828 (a liquid bisphenol A diglycidyl ether epoxy resin manufactured by Hexion Inc., Columbus, Ohio, USA);

[0078] 2.9 g Dyhard® UR500 (a difunctional latent urone accelerator in powder form manufactured by Alzchem Group AG, Trostberg, Germany).

[0079] The components were mixed thoroughly at a temperature of 50 to 60° C. until the mixture was uniform in consistency.

[0080] A moulding material was constructed having the following architecture:

[0081] (1) a layer of Evalith® S 5030 (a glass fibre fleece having an areal weight of 50 g/m.sup.2 manufactured by Johns Manville, Denver, Colo., USA,);

[0082] (2) a layer of a lightweight, fully synthetic non-woven fibre veil comprising a blend of polyester and polyamide fibres having an areal weight of 15 g/m.sup.2 (manufactured by Technical Fibre Products Limited, Burnside Mills, Kendal, Cumbria, United Kingdom); and

[0083] (3) a 65 g/m.sup.2 layer of resin composition 1.

[0084] The assembled layers were consolidated by passing through an S-wrap roller system heated to 80° C., to a form moulding material corresponding to moulding material 100 shown in FIG. 1.

[0085] A composite part was produced by placing the moulding material 100 into a composite tool treated with Zyvax® Watershield™ (a silicone-free water-soluble mould release agent manufactured by Freeman Manufacturing and Supply Company, Avon, Ohio, USA), followed by 3 layers of BB1000 fabric, (1000 g/m.sup.2 biaxial non-crimp glass fabric manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, United Kingdom) and 1 layer of Bleeder Lease B (62 g/m.sup.2 silicone treat nylon fabric from Airtech Europe Sarl, Differdange, Luxembourg.) and infused with Hexion RIM R135/RIM H 137 (liquid epoxy resin and hardener combination from Hexion Inc., Columbus, Ohio, USA) before curing at 80° C. for 6 hours under 1 bar pressure.

[0086] On cooling, the cured moulded part was removed for inspection and further testing.

Example 2

[0087] A resin composition (composition 2) was formulated from the same components in the same amounts as composition 1, but with the addition of 6 g Aerosil® R202 (a hydrophobic fumed silica rheology modifier manufactured by Evonik Resource Efficiency GmbH, Hanau-Wolfgang, Germany.

[0088] The components were mixed thoroughly at a temperature of 50 to 60° C. until the mixture was uniform in consistency.

[0089] A moulding material was constructed having the following architecture:

[0090] (1) a layer of LBB1200 fabric (1250 g/m.sup.2 triaxial non-crimp glass fabric manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, United Kingdom);

[0091] (2) a layer of Evalith® S 5030 (a glass fibre fleece having an areal weight of 50 g/m.sup.2 manufactured by Johns Manville, Denver, Colo., USA,);

[0092] (3) a layer of a lightweight, fully synthetic non-woven fibre veil comprising a blend of polyester and polyamide fibres having an areal weight of 15 g/m.sup.2 (manufactured by Technical Fibre Products Limited, Burnside Mills, Kendal, Cumbria, United Kingdom); and

[0093] (4) a 140 g/m.sup.2 layer of resin composition 2.

[0094] The assembled layers were consolidated by passing through an S-wrap roller system heated to 80° C., to form a moulding material corresponding to moulding material 200 shown in FIG. 2.

[0095] A composite part was produced by placing the moulding material 1 into a composite tool treated with Zyvax® Watershield™ (a silicone-free water-soluble mould release agent manufactured by Freeman Manufacturing and Supply Company, Avon, Ohio, USA), followed by 3 layers of BB1000 fabric, (1000 g/m.sup.2 biaxial non-crimp glass fabric manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, United Kingdom) and 1 layer of Bleeder Lease B (62 g/m.sup.2 silicone treat nylon fabric from Airtech Europe Sarl, Differdange, Luxembourg.) and infused with Hexion RIM R135/RIM H 137 (liquid epoxy resin and hardener combination from Hexion Inc., Columbus, Ohio, USA) before curing at 80° C. for 6 hours under 1 bar pressure.

[0096] On cooling, the cured moulded part was removed for inspection and further testing.

Example 3

[0097] Resin composition 2 was used to form a moulding material having the following architecture:

[0098] (1) a 400 g/m.sup.2 layer of resin composition 2;

[0099] (2) a layer of LBB1200 fabric (1250 g/m.sup.2 triaxial non-crimp glass fabric (manufactured by Hexcel Reinforcements UK Limited, Narborough, Leicestershire, United Kingdom);

[0100] (3) a layer of Evalith® S 5030 (a glass fibre fleece having an areal weight of 50 g/m.sup.2 manufactured by Johns Manville, Denver, Colo., USA,);

[0101] (4) a layer of a lightweight, fully synthetic non-woven fibre veil comprising a blend of polyester and polyamide fibres having an areal weight of 15 g/m.sup.2 manufactured by Technical Fibre Products Limited, Burnside Mills, Kendal, Cumbria, United Kingdom); and

[0102] (5) a 400 g/m.sup.2 layer of resin composition 2.

[0103] The assembled layers were consolidated by passing through an S-wrap roller system heated to 80° C., to form a moulding material corresponding to moulding material 200 shown in FIG. 2

[0104] The moulding material 200 was placed into a composite tool treated with Zyvax® Watershield™ (a silicone-free water soluble mould release agent manufactured by Freeman Manufacturing and Supply Company, Avon, Ohio, USA) with the resin composition layer (5) adjacent to the face of the mould. Two layers of HexPly® 79 (a prepreg manufactured by Hexcel GmbH, Neumarkt, Germany) were placed on top of the moulding material in the mould, i.e. next to the resin layer (1); and the assembly was cured under vacuum for 6 hours at 80° C. and 1 bar pressure. On cooling, the cured moulded part was removed for inspection and further testing.