Composites

Patent metadata

Field	Value
Publication number	US-2016167352-A1
Application number	US-201414904368-A
Country	US
Kind code	A1
Filing date	Jul 4, 2014
Priority date	Jul 12, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

A method of fabricating a composite material, the method comprises the steps of a) providing a first layer of a fibre reinforced polymer, preferably a thermoset FRP, b) providing an array of thermoplastic islands across at least a proportion of a major surface of the first layer, c) providing a second layer of a fibre reinforced polymer, preferably a thermoset FRP, d) laying the second layer over at least some of the islands, and e) securing the first and second layers together. There is also disclosed a composite which comprises a first layer of a fibre reinforced polymer and a second layer of a fibre reinforced polymer, between which is an intervening layer comprising an array of thermoplastic islands.

First claim

1 . A method of fabricating a composite material, the method comprising the steps of
a) providing a first layer of a fibre reinforced polymer, preferably a thermoset FRP, b) providing an array of thermoplastic islands across at least a proportion of a major surface of the first layer, c) providing a second layer of a fibre reinforced polymer, preferably a thermoset FRP, d) laying the second layer over at least some of the islands, and e) securing the first and second layers together.

2 . A method according to claim 1 , comprising securing the first and second layers together by the application of heat and/or pressure.

3 . A method according to claim 1 or 2 , comprising providing as each of the first and second layers a prepreg, for example a carbon fibre reinforced prepreg, preferably an epoxy matrix.

4 . A method according to any of claim 1 , 2 or 3 , wherein the islands are provided so as to extend over 20-80% of the area of the first layer, ideally 40-60%.

5 . A method according to any of claims 1 to 4 , comprising applying the thermoplastic islands across at least a proportion of a major surface of the first layer as a solution of thermoplastic in a solvent.

6 . A method according to any preceding claim, comprising providing the islands by means of one of ink jet printing, contact printing and non-contact printing or by use of a mask and spray method, preferably ink jet printing.

7 . A method according to any preceding claim, comprising repeating steps b) to e) to form successive layers of the composite material.

8 . A composite material comprising a first and second layer and a thermoplastic material, the first and second layer each comprise a thermoset fibre reinforced polymer, the thermoplastic material is discontinuously distributed at and/or towards the interface between the first and second layer.

9 . A material according to any of claims 8 , wherein the first and second layer are formed from the same or different thermoset polymers and/or may comprise the same or different fibres.

10 . A material according to claim 8 or 9 , wherein the thermoset polymers are selected from epoxy, polyesters, vinyl esters, phenolic resins and any other cross-linked thermosetting polymer.

11 . A material according to any of claim 8 , 9 or 10 , wherein the fibres are continuous and/or discontinuous and/or may be provided as aligned filaments or tows, or as a braided, knitted or woven mat or sheet.

12 . A material according to any of claims 8 to 11 , wherein the fibres are selected from one or more of carbon fibres, aramid fibres, glass and glass ceramic fibres, plastics fibres (e.g. Nylon, Terylene), hemp, wood and/or other organic fibres, inorganic fibres.

13 . A material according to any of claims 8 to 12 , wherein the volume fraction of fibre-to-polymer is from 0.01 to 5%, most preferably from 0.05 to 1% within the first and/or second layer.

14 . A material according to any of claims 8 to 13 , wherein the discontinuous distribution extends over some or all of the interface, and/or may be localised in certain defined regions.

15 . A material according to any of claims 8 to 14 , wherein the discontinuous distribution is in the form of an array of islands or zones, for example islands or zones of peak local concentration.

16 . A material according to claim 15 , wherein the islands comprise one or more thermoplastic polymers.

17 . A material according to claim 15 or 16 , wherein the islands comprise a first array of islands and a second array of islands, each of the first and second arrays being formed of different thermoplastics materials.

18 . A material according to any of claim 15 , 16 or 17 , wherein the islands extend over 20-80% of the area of the first layer, preferably 40-60%.

19 . A material according to any of claims 15 to 18 , wherein each of the islands has an area of less than 1 mm 2 , preferably less than 0.5 mm 2 , for example, less than 0.4, 0.3, 0.2, 0.1 mm 2 .

20 . A material according to any of claims 8 to 19 , wherein the thermoplastic material or polymer has a melting point of 50 to 200° C., preferably 75 to 190° C., most preferably 100 to 180° C.

21 . A material according to any of claims 8 to 20 , wherein the thermoplastic material or polymer has a molecular weight (NAMW) in the range of 3000 to 50000, preferably 4000 to 40000.

22 . A material according to any of claims 8 to 21 , wherein the thermoplastic material or polymer is selected from poly(ethylene glycol) (PEG), poly(methyl methacrylate) (PMMA) and similar thermoplastic polymers, preferably poly(ethylene glycol) and poly(methyl methacrylate).

23 . A material according to any of claims 8 to 23 , comprising a further intervening layer comprising an array of islands of thermoplastic polymer provided on the second layer.

24 . A material according to claim 23 , comprising a third layer comprising a fibre reinforced polymer, preferably a thermoset FRP, overlying the further intervening layer.

25 . A composite, preferably a self-healing composite, the composite comprising a first layer of fibre reinforced thermoset polymer and a second layer of fibre reinforced thermoset polymer and a thermoplastic polymer distributed at and/or towards the interface there between, the composite being stiffer than an equivalent fibre reinforced thermoset polymer composite absent the thermoplastic polymer.

26 . A composite, preferably a self-healing composite, the composite comprising a first layer of fibre reinforced thermoset polymer and a second layer of fibre reinforced thermoset polymer and a thermoplastic polymer distributed at and/or towards the interface therebetween, the composite having improved stiffness and/or interlaminar shear strength.

27 . A composite according to claim 25 or 26 , wherein the thermoplastic polymer is discontinuously distributed at and/or towards the interface between the first and second layer.

28 . A composite according to claim 25 , 26 or 27 , wherein the thermoplastic polymer is preferentially distributed at or towards the interface such that the relative concentration of thermoplastic polymer is at a peak at or towards the interface.

Assignees

• Univ Sheffield

Inventors

• Hodzic Alma
• Smith Patrick James

Classifications

• B32B2262/067

  Wood fibres · CPC title

• B32B3/10

  characterised by a discontinuous layer, i.e. formed of separate pieces of material · CPC title

• B32B2307/762

  Self-repairing, self-healing · CPC title

• B29K2033/12

  Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate · CPC title

• B29C70/42

  for producing articles of definite length, i.e. discrete articles · CPC title