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AssigneeTape Weaving Sweden AB
InventorsNandan Khokar, David Carlstedt, Soraia Pimenta, Leif Asp, James M. Glaser, Guillaume Moreau, Florence Rinn, Fredrik Ohlsson
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Novel ultra-thin unidirectional pre-preg tapes are disclosed. They can be used to produce ultra-thin woven, bias, multiaxial, chopped-oriented etc. types of pre-pregs. These ultra-thin pre-pregs enable production of composite material products with well-controlled dimensional tolerances and smooth/even surfaces. Further, they render the production of composite material products relatively simpler, tidier, quicker, and economical. The obtained composite material products are relatively thinner, lighter, and mechanically higher-performing.
A pre-preg sheet comprising a fibre reinforcement and either a thermoset or thermoplastic matrix material, wherein the fibre reinforcement comprises unidirectional spread fibres and the pre-preg sheet has a thickness of 20-40 micrometers, a volume fraction of fibres of at least 40% and a fibre areal weight of 15-50 g/m2, wherein the thermoset or thermoplastic matrix material is provided in the form of a layer attached to at least one surface of the fibre reinforcement and in a pattern to expose the unidirectional spread fibres, said layer being provided with pores or openings for exposing fibres of the reinforcement through said layer, wherein a weight of the matrix material is within the range of 5-50% of the total weight of the pre-preg sheet and wherein the patterned matrix material is arranged to spread, coalesce, engulf and embed the fibres of the fibre reinforcement on application of heat and pressure and form a layer having a thickness in the range of 2 to 4 micrometer on at least one surface of the pre-preg sheet, the layer of matrix material with the said thickness configured to function as a slip plane to enable mutual slipping of the fibres in plied sheets and at the same time resisting splitting of the resin and suppressing development of micro-cracks.
A pre-preg sheet comprising a fibre reinforcement and either a thermoset or thermoplastic matrix material, wherein the fibre reinforcement comprises unidirectional spread fibres and the pre-preg sheet has a thickness of 20-40 micrometers, a volume fraction of fibres of at least 40% and a fibre areal weight of 15-50 g/m2, wherein the matrix material is formed as a layer attached to at least one surface of the fibre reinforcement and provided in the form of either continuous or discontinuous lines, extending at least partly in a direction different from the direction of the fibres, or in the form of disconnected dots or speckles, the pre-preg displaying resin impregnated fibres in some parts and dry fibres with a plurality of micropores, openings or interstices between them in other parts, wherein a weight of the matrix material is within the range of 5-50% of the total weight of the pre-preg sheet and wherein the matrix material is arranged to spread, coalesce, engulf and embed the fibres of the fibre reinforcement on application of heat and pressure and form a layer having a thickness in the range of 2 to 4 micrometer on at least one surface of the pre-preg sheet, the layer of matrix material with the said thickness configured to function as a slip plane to enable mutual slipping of the fibres in plied sheets and at the same time resisting splitting of the resin and suppressing development of micro-cracks.
A multi-ply arrangement comprising at least two pre-preg sheets, each of the pre-preg sheets comprising a fibre reinforcement and either a thermoset or thermoplastic matrix material, wherein the fibre reinforcement comprises unidirectional spread fibres and the pre-preg sheet has a thickness of 20-40 micrometers, a volume fraction of fibres of at least 40% and a fibre areal weight of 15-50 g/m2, wherein the thermoset or thermoplastic matrix material is provided in the form of a layer attached to at least one surface of the fibre reinforcement and in a pattern to expose the unidirectional spread fibres, said layer being provided with pores or openings for exposing fibres of the reinforcement through said layer, wherein a weight of the matrix material is within the range of 5-50% of the total weight of the pre-preg sheet and wherein the patterned matrix material is arranged to spread, coalesce, engulf and embed the fibres of the fibre reinforcement on application of heat and pressure and form a layer having a thickness in the range of 2 to 4 micrometer on at least one surface of the pre-preq sheet, wherein the pre-preg sheets are arranged at least partly overlapping each other, wherein the overlapping pre-preg sheets have their fibres oriented in mutually different directions and wherein the thickness of the layer of matrix material between the two at least partly overlapping pre-preg sheets is in the range of 2 to 4 micrometer, the layer of matrix material with the said thickness configured to function as a slip plane to enable mutual slipping of the fibres in plied sheets and at the same time resisting splitting of the resin and suppressing development of micro-cracks.
Dependencies are inferred from the claim text.