WO2018121856A1 - Fiber reinforced thermoplastic composite - Google Patents

Fiber reinforced thermoplastic composite Download PDF

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Publication number
WO2018121856A1
WO2018121856A1 PCT/EP2016/082766 EP2016082766W WO2018121856A1 WO 2018121856 A1 WO2018121856 A1 WO 2018121856A1 EP 2016082766 W EP2016082766 W EP 2016082766W WO 2018121856 A1 WO2018121856 A1 WO 2018121856A1
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WO
WIPO (PCT)
Prior art keywords
reinforcement fabric
process according
layer
lcp film
fiber reinforced
Prior art date
Application number
PCT/EP2016/082766
Other languages
French (fr)
Inventor
Ozlem TURKARSLAN
Original Assignee
Kordsa Teknik Tekstil Anonim Sirketi
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kordsa Teknik Tekstil Anonim Sirketi filed Critical Kordsa Teknik Tekstil Anonim Sirketi
Priority to PCT/EP2016/082766 priority Critical patent/WO2018121856A1/en
Publication of WO2018121856A1 publication Critical patent/WO2018121856A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B32B5/12—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer characterised by the relative arrangement of fibres or filaments of different layers, e.g. the fibres or filaments being parallel or perpendicular to each other
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/12—Layered products comprising a layer of synthetic resin next to a fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/28—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B32B5/024—Woven fabric
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2250/00—Layers arrangement
    • B32B2250/40—Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
    • B32B2260/02—Composition of the impregnated, bonded or embedded layer
    • B32B2260/021—Fibrous or filamentary layer
    • B32B2260/023—Two or more layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
    • B32B2260/04—Impregnation, embedding, or binder material
    • B32B2260/046—Synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/10—Inorganic fibres
    • B32B2262/106—Carbon fibres, e.g. graphite fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/42—Polarizing, birefringent, filtering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/51—Elastic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/514—Oriented
    • B32B2307/516—Oriented mono-axially
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/732—Dimensional properties
    • B32B2307/734—Dimensional stability

Definitions

  • Present invention is related with processes and fiber reinforced thermoplastic composite and processes for making the same.
  • Fiber-reinforced polymer is a composite material made of a polymer matrix reinforced with fibers. Reinforcement fibers may be short or long continuous fibers made of glass, carbon and aramid. Also, the polymer can be either thermoset resin, such as epoxy, or thermoplastic, such as polyolefin, polyamide, polyester, polyketone.
  • Liquid-crystal polymers are a class of aromatic polymers. They are extremely unreactive and inert, and highly resistant to fire.
  • Thermotropic liquid crystal polymers such as aromatic polyesters, aromatic-aliphatic polyesters, poly(ester-amides) etc. form highly oriented fibers and films besides they can be thermally fused together to form a laminate with reinforcement fiber.
  • Thermotropic LCP's are anisotropic in the melt phase and parallel ordered in the nematic phase.
  • the monomers, from which the polymers synthesized have rigid, rod-like structures making fibers and films drawn, made of these polymers, inherently crystalline and stiff.
  • LCP offers several advantages in terms of very poor oxygen and water permeability, flame retardant properties, resistances to chemicals and corrosion.
  • thermoplastic resins specifically liquid crystal polymers
  • thermoplastic composite laminates formed from blends of two thermotropic liquid crystal polymers which have overlapping processing temperature ranges but different minimum processing temperatures, and which are incompatible or immiscible in the solid phase are described in US 5,238,638 and US
  • thermo-fixing treatment since the thermo-fixing treatment is missing these documents, stabilization of the material and minimizing the problems related the process could not be accomplished. Therefore, these methods are not enough to give dimensional stability to the reinforcement material.
  • a difficulty encountered in the production of fiber-reinforced polymer composites is the high mixing energy required to mix or blend the base polymer with the reinforcement fiber. This is due largely to the fact that all the common reinforcing materials are solid.
  • the present invention provides a fiber reinforced thermoplastic composite such that reinforcement fabric laminated with at least four unidirectional oriented layers of thermotropic liquid crystal polymer (LCP) film to cover the reinforcement fabric in all directions.
  • LCP thermotropic liquid crystal polymer
  • the process for preparing a fiber reinforced thermoplastic composite comprises the steps of; extruding a LCP film through a slot die with the predetermined temperature above 270 °C and below 330 °C to obtain thermotropic liquid crystal polymer film as thermofixing matrix; cutting at least four layers from the thermoplastic LCP film; placing at least two of the four thermoplastic LCP film layers into a mold unidirectionally; placing the reinforcement fabric into the mold in such a way that the reinforcement fabric is on the two thermoplastic LCP film layers placed into the mold; placing the other remained at least two of the four thermoplastic LCP film layers on reinforcement fabric laying into the mold unidirectionally in such a way that the other remained two thermoplastic LCP film layers are on the reinforcement fabric, to obtain thermofixed laminate; placing the mold in which the laminate is provided into a pressing device, which is preheated at 280 °C - 320 °C; melting the laminate in the pressing device by applying maximum 10 bars of pressure for maximum 10 minutes and impregnating the reinforcement fabric with the thermo
  • One of the objects of the invention is to provide fiber reinforced thermoplastic composites and a process for preparing them that gives dimensional stability to the reinforcement material.
  • Fiber reinforced polymer (FRP) composites are compositions that composed of fibers and polymers.
  • FRPs are commonly used in the aerospace, automotive, marine, and construction industries. They are commonly found in ballistic armor as well.
  • Use of thermoplastic resins, specifically liquid crystal polymers, preparation processes of FRP's are subjects of many documents in the prior art. However, they are not enough to provide a composite or process with desired properties.
  • the documents in the prior art are inadequate to obtain composite material which is dimensionally stable enough also composites having long, continuous strands of reinforcement fibers cannot be formed easily in conventional processes. Therefore, special methods are required in order to manufacture such composites with good properties fiber reinforced thermoplastic composites and processes for making the same are provided by the present invention.
  • the present invention provides a fiber reinforced thermoplastic composite such that reinforcement fabric laminated with at least four unidirectional oriented layers of thermotropic liquid crystal polymer (LCP) film to cover the reinforcement fabric in all directions.
  • LCP thermotropic liquid crystal polymer
  • At least one side of the reinforcement fabric is laid by at least one first layer which is 90° direction whereas at least one other side thereof is laid by at least one second layer which is 0° directions. Furthermore, at least one third layer provided next to the said first layer is 0° directions and at least one forth layer provided next to the said second layer is 90° directions.
  • reinforcement fabric is balanced reinforcement fabrics or unidirectional reinforcement fabrics. The most preferably reinforcement fabric is woven balanced carbon fabric.
  • the present invention also provides a process for preparing a fiber reinforced thermoplastic composites where thin unidirectional layers of thermotropic liquid crystal polymer film is laminated onto reinforcement fabrics under heat and pressure.
  • This method basically comprises the steps of lay-up of reinforcement fabric and unidirectional thermotropic LCP film, and heat pressing.
  • This method finds particular utility where holding all the weft and warp yarns together, preventing slippage but enabling drapability with the help of thin film layer, which is fused via heat and pressure. This does not only give better orientation in the final part but also improve the mechanical quality through thickness direction.
  • the process for preparing a fiber reinforced thermoplastic composite comprises the steps of; extruding a LCP film through a slot die with the predetermined temperature preferably above 270 °C and below 330 °C to obtain thermotropic liquid crystal polymer film as thermofixing matrix; cutting at least four layers from the thermoplastic LCP film; placing at least two of the four thermoplastic LCP film layers into a mold unidirectionally; placing the reinforcement fabric into the mold in such a way that the reinforcement fabric is on the two thermoplastic LCP film layers placed into the mold; placing the other remained at least two of the four thermoplastic LCP film layers on reinforcement fabric laying into the mold unidirectionally in such a way that the other remained two thermoplastic LCP film layers are on the reinforcement fabric, to obtain thermofixed laminate; placing the mold in which the laminate is provided into a pressing device, which is preferably preheated at 280°C - 320 °C; melting the laminate in the pressing device by applying preferably maximum 10 bars of pressure preferably for maximum 10 minutes and impregna
  • At least one side of the reinforcement fabric is laid by at least one first layer which is adjusted to 90° directions whereas at least one other side thereof is laid by at least one second layer which is adjusted to 0° directions. Furthermore, at least one third layer provided next to the said first layer is 0° direction and at least one forth layer provided next to the said second layer is 90° direction.
  • Liquid crystal polymers are not only easy to process but also give very good mechanical properties to the end product due to semi rigid nature of the macromolecules.
  • LCP films are directly spun from their thermotropic melt at temperature range of 250 - 350 °C.
  • the macromolecules orient in the direction of flow giving strength without much drawing. Since the relaxation time is quite long, molecular orientation is retained during and after solidification.
  • LCP offers several advantages in terms of very poor oxygen and water permeability, flame retardant properties, resistances to chemicals and corrosion.
  • a thermoplastic film is utilized and through pressure molding this film is laminated onto the reinforcement fabric rather than carbon fiber and used for fixation of warps and wefts of carbon fabric.
  • a thin film without any surface treatment is preferred in this invention.
  • a batch process is disclosed according to present invention, the proposed method is also suitable for continuous process.
  • the film extruding through a slot die shows 0° tensile strength and Young's modulus are 0.6 - 0.7 GPa and 51 - 52 GPa respectively.
  • Thickness of the extruded film is preferably 40 to 50 micron and it is unidirectional and anisotropic. So it is proposed to use such a film in both 0° and 90° directions.
  • the reinforcement fabric is balanced, plain weaved carbon fabric made of 12 K filaments. Fixing the warps and wefts through thin thermoplastic liquid crystal polymer film application via heating and applying some pressure did not only give dimensional stability to the fabric but also elastic behavior. It is easy to bend it and when the bending force is relaxed the fabric did not deform. The film covered the whole surface holding all the yarns together providing advantages in composite production.
  • the reinforcement fabric thermofixed with LCP film is impregnated with a thermosetting resin, such as epoxy, to form a fiber reinforced thermoset composite.
  • a thermosetting resin such as epoxy
  • the reinforcement fabric thermofixed with LCP film is laid-up into the mold and a thermosetting resin is transferred through different techniques preferably vacuum infusion or resin transfer molding.
  • weaving styles of the reinforcement fabric is preferably plain, twill and/or harness sateen.
  • the reinforcement fabric preferably is made of carbon, glass, aramid and/or hybrids.
  • the LCP film shows a compatible behavior with the reinforcement fabric and its sizing, delamination is not observed.
  • the fiber reinforced thermoplastic composites obtained by the process according the present invention is used as preform, laid-up in the female mold and re-shaped with the help of male mold to form a fiber reinforced thermoplastic composite.
  • thermoplastic LCP film is fed-up right before the wind-up and then the lay-up composed of LCP and woven fabric layers pass through heated cylinders and compressed during weaving process.
  • This thermotropic LCP film is also fed-up right after let-off, the laminate having the layers of LCP film and reinforcement fabric go through heated cylinders and heat pressed and then impregnated with resin during prepregging process.
  • Fiber reinforced thermoplastic composites is obtained such that thermofixing of reinforcement fibers and / or fabrics are achieved via incorporating thermoplastic material into.

Abstract

The present invention provides a fiber reinforced thermoplastic composite wherein; reinforcement fabric laminated with at least four unidirectional oriented layers of thermotropic LCP film to cover the reinforcement fabric in all directions.

Description

DESCRIPTION
FIBER REINFORCED THERMOPLASTIC COMPOSITE
Field of the Invention
Present invention is related with processes and fiber reinforced thermoplastic composite and processes for making the same.
Background of the Invention
Fiber-reinforced polymer is a composite material made of a polymer matrix reinforced with fibers. Reinforcement fibers may be short or long continuous fibers made of glass, carbon and aramid. Also, the polymer can be either thermoset resin, such as epoxy, or thermoplastic, such as polyolefin, polyamide, polyester, polyketone.
Liquid-crystal polymers (LCPs) are a class of aromatic polymers. They are extremely unreactive and inert, and highly resistant to fire. Thermotropic liquid crystal polymers, such as aromatic polyesters, aromatic-aliphatic polyesters, poly(ester-amides) etc. form highly oriented fibers and films besides they can be thermally fused together to form a laminate with reinforcement fiber. Thermotropic LCP's are anisotropic in the melt phase and parallel ordered in the nematic phase. The monomers, from which the polymers synthesized, have rigid, rod-like structures making fibers and films drawn, made of these polymers, inherently crystalline and stiff. LCP offers several advantages in terms of very poor oxygen and water permeability, flame retardant properties, resistances to chemicals and corrosion.
Use of thermoplastic resins, specifically liquid crystal polymers, are subjects of many documents in the prior art. Self-reinforced thermoplastic composite laminates formed from blends of two thermotropic liquid crystal polymers which have overlapping processing temperature ranges but different minimum processing temperatures, and which are incompatible or immiscible in the solid phase are described in US 5,238,638 and US
5,260,380. Thermotropic liquid crystal polymers in multiaxially oriented laminates thermally fused are discussed in US 4,384,016. In US 5,106,680 a method describing carbon fiber and thermoplastic material intermingled besides adhered with surface treatment is documented. Continuous and linearly intermixed liquid crystal and carbon fiber tows and composites molded are patented by Cytec Technology Corporation (US 6,045,906).
Basically, all of these inventions relate to multi-axial oriented high performance laminates made of uniaxially oriented sheets of thermoplastic liquid crystal polymer. However, the methods mentioned in these documents do not include thermo-fixing treatment, since the thermo-fixing treatment is missing these documents, stabilization of the material and minimizing the problems related the process could not be accomplished. Therefore, these methods are not enough to give dimensional stability to the reinforcement material. Also, a difficulty encountered in the production of fiber-reinforced polymer composites is the high mixing energy required to mix or blend the base polymer with the reinforcement fiber. This is due largely to the fact that all the common reinforcing materials are solid. Furthermore, composites having long, continuous strands of reinforcing fibers cannot be formed easily in conventional mixers, so that special methods are required in order to manufacture such composites. However, methods in the prior art are insufficient to use thermosetting resins and fail to increase dimensional frictions. Therefore, there is a need of a more useful process for obtaining more dimensionally stable material
Brief Description of the Invention
The present invention provides a fiber reinforced thermoplastic composite such that reinforcement fabric laminated with at least four unidirectional oriented layers of thermotropic liquid crystal polymer (LCP) film to cover the reinforcement fabric in all directions.
The process for preparing a fiber reinforced thermoplastic composite according to present invention comprises the steps of; extruding a LCP film through a slot die with the predetermined temperature above 270 °C and below 330 °C to obtain thermotropic liquid crystal polymer film as thermofixing matrix; cutting at least four layers from the thermoplastic LCP film; placing at least two of the four thermoplastic LCP film layers into a mold unidirectionally; placing the reinforcement fabric into the mold in such a way that the reinforcement fabric is on the two thermoplastic LCP film layers placed into the mold; placing the other remained at least two of the four thermoplastic LCP film layers on reinforcement fabric laying into the mold unidirectionally in such a way that the other remained two thermoplastic LCP film layers are on the reinforcement fabric, to obtain thermofixed laminate; placing the mold in which the laminate is provided into a pressing device, which is preheated at 280 °C - 320 °C; melting the laminate in the pressing device by applying maximum 10 bars of pressure for maximum 10 minutes and impregnating the reinforcement fabric with the thermoplastic LCP film layers to obtain fiber reinforced thermoplastic composite.
More useful process to obtain more dimensionally stable material with minimization of the problems is accomplished by the process for preparing fiber reinforced thermoplastic composite. Also, fiber reinforced thermoplastic composite is obtained such that thermofixing of reinforcement fibers and / or fabrics are achieved via incorporating thermoplastic material into. Object of the Invention
One of the objects of the invention is to provide fiber reinforced thermoplastic composites and a process for preparing them that gives dimensional stability to the reinforcement material.
Other object of the invention is to provide fiber reinforced thermoplastic composites and a process for preparing them such that thermofixing of reinforcement fibers and / or fabrics are achieved via incorporating thermoplastic material into. Another object of the invention is to provide a process of preparation of fiber reinforced thermoplastic composites that the orientation is retained during and after solidification.
Detailed Description of the Invention Fiber reinforced polymer (FRP) composites are compositions that composed of fibers and polymers. FRPs are commonly used in the aerospace, automotive, marine, and construction industries. They are commonly found in ballistic armor as well. Use of thermoplastic resins, specifically liquid crystal polymers, preparation processes of FRP's are subjects of many documents in the prior art. However, they are not enough to provide a composite or process with desired properties. Especially, the documents in the prior art are inadequate to obtain composite material which is dimensionally stable enough also composites having long, continuous strands of reinforcement fibers cannot be formed easily in conventional processes. Therefore, special methods are required in order to manufacture such composites with good properties fiber reinforced thermoplastic composites and processes for making the same are provided by the present invention.
The present invention provides a fiber reinforced thermoplastic composite such that reinforcement fabric laminated with at least four unidirectional oriented layers of thermotropic liquid crystal polymer (LCP) film to cover the reinforcement fabric in all directions. As a result, there are at least four thermotropic LPC films positioned unidirectionally such that at least two films are provided on each side of said reinforcement fabric.
In preferred embodiment of the process according to present invention, at least one side of the reinforcement fabric is laid by at least one first layer which is 90° direction whereas at least one other side thereof is laid by at least one second layer which is 0° directions. Furthermore, at least one third layer provided next to the said first layer is 0° directions and at least one forth layer provided next to the said second layer is 90° directions. In another preferred embodiment of the composite according to present invention, reinforcement fabric is balanced reinforcement fabrics or unidirectional reinforcement fabrics. The most preferably reinforcement fabric is woven balanced carbon fabric.
The present invention also provides a process for preparing a fiber reinforced thermoplastic composites where thin unidirectional layers of thermotropic liquid crystal polymer film is laminated onto reinforcement fabrics under heat and pressure. This method basically comprises the steps of lay-up of reinforcement fabric and unidirectional thermotropic LCP film, and heat pressing. This method finds particular utility where holding all the weft and warp yarns together, preventing slippage but enabling drapability with the help of thin film layer, which is fused via heat and pressure. This does not only give better orientation in the final part but also improve the mechanical quality through thickness direction.
The process for preparing a fiber reinforced thermoplastic composite according to present invention comprises the steps of; extruding a LCP film through a slot die with the predetermined temperature preferably above 270 °C and below 330 °C to obtain thermotropic liquid crystal polymer film as thermofixing matrix; cutting at least four layers from the thermoplastic LCP film; placing at least two of the four thermoplastic LCP film layers into a mold unidirectionally; placing the reinforcement fabric into the mold in such a way that the reinforcement fabric is on the two thermoplastic LCP film layers placed into the mold; placing the other remained at least two of the four thermoplastic LCP film layers on reinforcement fabric laying into the mold unidirectionally in such a way that the other remained two thermoplastic LCP film layers are on the reinforcement fabric, to obtain thermofixed laminate; placing the mold in which the laminate is provided into a pressing device, which is preferably preheated at 280°C - 320 °C; melting the laminate in the pressing device by applying preferably maximum 10 bars of pressure preferably for maximum 10 minutes and impregnating the reinforcement fabric with the thermoplastic LCP film layers to obtain fiber reinforced thermoplastic composite. In preferred embodiment of the process according to present invention, at least one side of the reinforcement fabric is laid by at least one first layer which is adjusted to 90° directions whereas at least one other side thereof is laid by at least one second layer which is adjusted to 0° directions. Furthermore, at least one third layer provided next to the said first layer is 0° direction and at least one forth layer provided next to the said second layer is 90° direction.
Liquid crystal polymers (LCP) are not only easy to process but also give very good mechanical properties to the end product due to semi rigid nature of the macromolecules. LCP films are directly spun from their thermotropic melt at temperature range of 250 - 350 °C. The macromolecules orient in the direction of flow giving strength without much drawing. Since the relaxation time is quite long, molecular orientation is retained during and after solidification. LCP offers several advantages in terms of very poor oxygen and water permeability, flame retardant properties, resistances to chemicals and corrosion. In the process according to present invention, a thermoplastic film is utilized and through pressure molding this film is laminated onto the reinforcement fabric rather than carbon fiber and used for fixation of warps and wefts of carbon fabric. Instead of thermoplastic yarns with different surface finishes which could be act as plasticizer in melted form, a thin film without any surface treatment is preferred in this invention. Although, a batch process is disclosed according to present invention, the proposed method is also suitable for continuous process.
The process according to present invention, the film extruding through a slot die shows 0° tensile strength and Young's modulus are 0.6 - 0.7 GPa and 51 - 52 GPa respectively. Thickness of the extruded film is preferably 40 to 50 micron and it is unidirectional and anisotropic. So it is proposed to use such a film in both 0° and 90° directions.
In one alternative embodiment of the composite and process according to present invention the reinforcement fabric is balanced, plain weaved carbon fabric made of 12 K filaments. Fixing the warps and wefts through thin thermoplastic liquid crystal polymer film application via heating and applying some pressure did not only give dimensional stability to the fabric but also elastic behavior. It is easy to bend it and when the bending force is relaxed the fabric did not deform. The film covered the whole surface holding all the yarns together providing advantages in composite production.
In a process according to the present invention; the reinforcement fabric thermofixed with LCP film is impregnated with a thermosetting resin, such as epoxy, to form a fiber reinforced thermoset composite. The reinforcement fabric thermofixed with LCP film is laid-up into the mold and a thermosetting resin is transferred through different techniques preferably vacuum infusion or resin transfer molding.
In a preferred embodiment of the composite according to present invention, weaving styles of the reinforcement fabric is preferably plain, twill and/or harness sateen. The reinforcement fabric preferably is made of carbon, glass, aramid and/or hybrids. The LCP film shows a compatible behavior with the reinforcement fabric and its sizing, delamination is not observed.
In one embodiment of the present invention the fiber reinforced thermoplastic composites obtained by the process according the present invention is used as preform, laid-up in the female mold and re-shaped with the help of male mold to form a fiber reinforced thermoplastic composite.
In an alternative embodiment of the process according to present invention, the thermoplastic LCP film is fed-up right before the wind-up and then the lay-up composed of LCP and woven fabric layers pass through heated cylinders and compressed during weaving process. This thermotropic LCP film is also fed-up right after let-off, the laminate having the layers of LCP film and reinforcement fabric go through heated cylinders and heat pressed and then impregnated with resin during prepregging process.
More useful process for obtaining more dimensionally stable material with minimization of the problems is accomplished by the process for preparing fiber reinforced thermoplastic composites. Also, fiber reinforced thermoplastic composites is obtained such that thermofixing of reinforcement fibers and / or fabrics are achieved via incorporating thermoplastic material into.

Claims

1 - A fiber reinforced thermoplastic composite wherein; reinforcement fabric laminated with at least four unidirectional oriented layers of thermotropic LCP film to cover the reinforcement fabric in all directions.
2- A fiber reinforced thermoplastic composite according to claim 1 wherein; at least one side of the reinforcement fabric is laid by at least one first layer which is 90° direction whereas at least one other side thereof is laid by at least one second layer which is 0° directions.
3- A fiber reinforced thermoplastic composite according to claim 1 wherein; at least one third layer provided next to the said first layer is 0° directions.
4- A fiber reinforced thermoplastic composite according to claim 1 wherein; at least one forth layer provided next to the said second layer is 90° directions.
5- A composite according to claim 1 wherein; reinforcement fabric is balanced reinforcement fabrics or unidirectional reinforcement fabrics.
6- A composite according to claim 1 wherein; reinforcement fabric is woven balanced carbon fabric.
7- A process for preparing a composite according to proceeding claims comprising the steps of
extruding a LCP film through a slot die with the predetermined temperature to obtain thermotropic liquid crystal polymer film as thermofixing matrix;
cutting at least four layers from the thermoplastic LCP film;
placing at least two of the four thermoplastic LCP film layers into a mold unidirectionally;
placing the reinforcement fabric into the mold in such a way that the reinforcement fabric is on the two thermoplastic LCP film layers placed into the mold;
placing the other remained at least two of the four thermoplastic LCP film layers on reinforcement fabric laying into the mold unidirectionally in such a way that the other remained two thermoplastic LCP film layers are on the reinforcement fabric, to obtain thermofixed laminate;
placing the mold in which the laminate is provided into a pre-heated pressing device;
melting the laminate in the pressing device by applying predetermined pressure and
impregnating the reinforcement fabric with the thermoplastic LCP film layers to obtain fiber reinforced thermoplastic composite.
8- A process according to claim 7 wherein; predetermined temperature is above 270 °C and below 330 °C
9- A process according to claim 7 wherein; the pressing device is pre-heated to 280 °C to 320 °C. 10- A process according to claim 7 wherein; predetermined pressure is maximum 10 bars.
1 1 - A process according to claim 7 and claim 10 wherein; predetermined pressure is applied for maximum 10 minutes.
12- A process according to claim 7 wherein; at least one side of the reinforcement fabric is laid by at least one first layer which is adjusted to 90° direction whereas at least one other side thereof is laid by at least one second layer which is adjusted to 0° direction.
13- A process according to claim 7 and claim 12 wherein; at least one third layer provided next to the said first layer is 0° directions.
14- A process according to claim 7 and claim 12 wherein; at least one forth layer provided next to the said second layer is 90° directions.
15- . A process according to claim 7 wherein; the thickness of the extruded LCP film is 40 to 50 micron. 16-A process according to claim 7 wherein; the reinforcement fabric thermofixed with
LCP film is impregnating with a thermosetting resin to form a fiber reinforced thermoset composite. 17- A process according to claim 16 wherein; thermosetting resin is epoxy.
18- A process according to claim 16 wherein; the reinforcement fabric thermofixed with LCP film is laid-up into the mold
19- A process according to claim 16 wherein; thermosetting resin is transferred through vacuum infusion or resin transfer molding.
PCT/EP2016/082766 2016-12-28 2016-12-28 Fiber reinforced thermoplastic composite WO2018121856A1 (en)

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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4384016A (en) 1981-08-06 1983-05-17 Celanese Corporation Mutiaxially oriented high performance laminates comprised of uniaxially oriented sheets of thermotropic liquid crystal polymers
WO1991001879A1 (en) * 1989-08-10 1991-02-21 University Of Akron Self reinforced thermoplastic composite laminate
US5106680A (en) 1990-05-08 1992-04-21 Hoechst Celanese Corporation Adhesion between carbon fibers and thermoplastic matrix materials in carbon fiber composites by using multifunctional amine and azo compounds as bridging agents
US5238638A (en) 1990-08-16 1993-08-24 The University Of Akron Process for preparing a self-reinforced thermoplastic composite laminate
US5248360A (en) * 1992-02-03 1993-09-28 The Dow Chemical Company Process for preparing composites based on oriented mesogenic thermoset resins
US5260380A (en) 1992-01-23 1993-11-09 The University Of Akron Self-reinforced composite and process for preparing same
EP0697278A1 (en) * 1994-08-16 1996-02-21 Hoechst Celanese Corporation Liquid crystal polymer-metal laminate and a method of producing such a laminate
US6045906A (en) 1984-03-15 2000-04-04 Cytec Technology Corp. Continuous, linearly intermixed fiber tows and composite molded article thereform
US20070003710A1 (en) * 2005-06-30 2007-01-04 Lynch George D Liquid crystalline polymer barrier resin films and processes thereof

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4384016A (en) 1981-08-06 1983-05-17 Celanese Corporation Mutiaxially oriented high performance laminates comprised of uniaxially oriented sheets of thermotropic liquid crystal polymers
US6045906A (en) 1984-03-15 2000-04-04 Cytec Technology Corp. Continuous, linearly intermixed fiber tows and composite molded article thereform
WO1991001879A1 (en) * 1989-08-10 1991-02-21 University Of Akron Self reinforced thermoplastic composite laminate
US5106680A (en) 1990-05-08 1992-04-21 Hoechst Celanese Corporation Adhesion between carbon fibers and thermoplastic matrix materials in carbon fiber composites by using multifunctional amine and azo compounds as bridging agents
US5238638A (en) 1990-08-16 1993-08-24 The University Of Akron Process for preparing a self-reinforced thermoplastic composite laminate
US5260380A (en) 1992-01-23 1993-11-09 The University Of Akron Self-reinforced composite and process for preparing same
US5248360A (en) * 1992-02-03 1993-09-28 The Dow Chemical Company Process for preparing composites based on oriented mesogenic thermoset resins
EP0697278A1 (en) * 1994-08-16 1996-02-21 Hoechst Celanese Corporation Liquid crystal polymer-metal laminate and a method of producing such a laminate
US20070003710A1 (en) * 2005-06-30 2007-01-04 Lynch George D Liquid crystalline polymer barrier resin films and processes thereof

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