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
  • 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
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/08—Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced 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
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/304—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• • 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
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/308—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising acrylic (co)polymers
• • 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
  • B32B5/22—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 the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
• • 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
  • B32B2262/02—Synthetic macromolecular fibres
  • B32B2262/0261—Polyamide 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
  • 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
  • B32B2305/00—Condition, form or state of the layers or laminate
  • B32B2305/02—Cellular or porous
  • B32B2305/026—Porous
• • 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
  • B32B2307/70—Other properties
  • B32B2307/72—Density
• • 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
  • B32B2327/00—Polyvinylhalogenides
  • B32B2327/06—PVC, i.e. polyvinylchloride
• • 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
  • B32B2333/00—Polymers of unsaturated acids or derivatives thereof
  • B32B2333/04—Polymers of esters
  • B32B2333/12—Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate

Definitions

• the present invention relates to a composite material based on thermosetting resin reinforced with carbon filaments, rethermoformable at will after polymerization of the resin.
• thermoformable composite orthosis material intended to form an orthosis element, composed of a polymerized resin reinforced with fibers.
• the fibers or filaments used are intended to reinforce the composite and are chosen for this purpose from the category of materials whose elastic modulus is> 50 GPa.
• these filaments there are carbon, glass, aramid filaments. Generally these filaments (or multi-filaments) are woven to be incorporated into the re ⁇ sine.
• Reinforcement with glass filaments gives the material good resistance, it allows rethermoforming after polymerization of the resin, but the density of the glass leads to a relatively heavy material, which in the field of orthopedics in particular constitutes a serious drawback.
• the carbon filaments cannot elongate during the thermoforming of the composite material.
• the wettability of these carbon filaments by the resin is not very good.
• one face of the reinforcing ply is subjected to a tensile force while the opposite face is subjected to a compressive force during the bending of the composite.
• the resin cracks on the convex face and forms beads on the concave face.
• the composite material delaminates. In all cases, such a material can only be thermoformed using a special tool and can then no longer be rethermo-forroated, which prevents the successive adaptations that an orthosis may require, as explained. previously.
• the object of the present invention is to allow the production of a light composite material, reinforced with carbon filaments which is rethermoformable at will.
• the present invention relates to a thermoformable laminate material according to claim 1.
• the structure of the composite material according to the invention is always symmetrical with respect to a middle layer which can be produced in particular from polyurethanes, polyolefins, polyvinyl chloride (PVC), etc. in the form of a layer 0.1 to 10 mm thick, porous with open pores and having a modulus of elasticity ⁇ 2 GPa and a density less than 1.
• a middle layer which can be produced in particular from polyurethanes, polyolefins, polyvinyl chloride (PVC), etc. in the form of a layer 0.1 to 10 mm thick, porous with open pores and having a modulus of elasticity ⁇ 2 GPa and a density less than 1.
• the material comprises at least one layer of reinforcing filaments which can be in the form of a fabric whose elastic modulus is> 50 GPa composed of carbon filaments.
• the whole of this structure is embedded in a resin matrix which is a thermosetting resin, preferably a mixture of an unsaturated resin with low functionality, which confers flexibility, and of an unsaturated resin with high functionality, which confers hardness, the proportion between the two, varying according to the desired hardness / flexibility balance.
• the polymerization initiator is an organic peroxide.
• fine, light, porous, inorganic or organic fillers can be incorporated into the mixture.
• the fine filler can be obtained by cryogenic grinding of porous polymers, for example porous PVC whose density is less than 1.
• the resin can be tinted using a compatible dye and a certain proportion of high mineral charges. thermal conductivity can be incorporated to speed up polymerization.
• the structure described above is complemented by at least two plies of a fabric whose elastic modulus is between 2 and 5 GPa and the elongation at break is between 40% and 300%.
• These thermoplastic fabrics are commonly produced from polyesters, aliphatic polyamides, polyacrylics, etc.
• These two plies with modulus of elasticity are arranged on the side of the external face of each ply of reinforcing filaments. At least two plies with additional modulus of elasticity can be inserted respectively between the middle layer and the two plies of carbon filaments.
• each ply of carbon filaments and each ply with medium modulus of elasticity can be doubled so as to be in adjacent pairs in the composite material rather than in the form of a single ply.
• the middle layer can also be doubled, a sheet of carbon filaments being inserted between the two middle layers.
• the middle layer being formed by a polymer with open pores
• the resin can penetrate to a surface depth by the two faces of this middle layer and form a homogeneous binding interphase.
• This characteristic is extremely important, insofar as it is well known in interface theory, that the presence of an interphase avoids the concentration of forces and thus makes it possible to reduce the risks of delamination under the effect of shearing.
• This interphase is also extremely important for transferring the reinforcing effect between the different layers of the laminate material.
• this middle layer gives the laminated material flexibility, from low to medium temperature, and at the same time makes it compressible. Thanks to this faculty of deformation and compression and to the symmetrical structure of the layers, the stresses can be dissipated and redistributed increasing the durability of the material and its capacity for thermoforming and multiple rethermoforming.
• Two methacrylic resins marketed with different functionalities are used, Degaplast, Orthocryl. Although the proportions can be varied due to the desired properties, the preferred mixture for orthopedic applications consists of 20 parts by weight of low functionality resin and 80 parts by weight of high functionality resin.
• the benzoyl peroxide initiator (Roland Frey 5504 Othmarsingen, Switzerland) used is of the order of 1 to 3% by weight.
• a further 2% by weight of a Ruconix blue dye (Ruff and Co, Glattbrugg, Switzerland) is added.
• the fabric As for the fabric whose elastic modulus is between 2 and 5 GPa, it is a Perlon® polyamide fabric reference 028400-120 (Roland Frey 5504 Othmarsingen, Switzerland).
• porous middle layer is 3 mm thick PVC Aire or Simosel.
• the structure of the laminate material is as follows:
• a set of five components in the order listed above is placed in a 30 x 60 cm mold coated with a humidified PVA film and used for demolding.
• the mold is closed and a vacuum of 78.5 kPa is produced in order to inject 700 g of the above-mentioned methacrylic resin with the 3% benzoyl peroxid therein.
• the whole is left to polymerize for 30 min.
• the laminated material of this example differs from that of Example 1 only by the fact that two sheets of Perlon fabric are interposed between components 2 and 3 as well as between components 3 and 4 of Example 1.
• the laminated material of this example differs from that of Example 1 only in the structure of the middle layer 3 which comprises two layers of PVC Aire of 3mm between which two layers of the fabric of carbon multi-filaments are arranged, so that the middle layer is itself formed of a laminate.
• the laminate material of this example differs from that of Example 1 only by the fact of the elimination of the components 1 and 5 each consisting of two layers of Perlon fabric.
• the samples of the laminated material according to Examples 1 to 4 were subjected to thermoforming tests using a hot air fan delivering air at 250 ° C.
• the heated samples are quickly bent at right angles to form a round.
• After cooling, the samples were reheated to quickly straighten them to bring them back to their initial state.
• thermomechanical and dynamic properties were carried out using the samples produced according to Examples 3 and 4 which 1 'were compared with four other samples 5, 6, 7 and 8 each composed of the resin matrix in which only some of the components of the laminate material according to Example 1 were incorporated, namely s
• Tfr brittleness temperature temperature of the transition from the elastic phase to the transition phase
• the material is thermoformable when heated to a temperature between Tg alpha and Tfl.
• Tfl is equal to the thermoformability temperature Tth, because at this temperature, the mobility of the chains polymers reaches the maximum.
• a new beta transition zone appears between -20 ° C and + 6B ° C (Tg beta: 47 ° C). Its presence explains the high value of Tandelta and the improvement in impact resistance at room temperature (25 ° C). At this temperature, the PVC-free material is still in the elastic phase.
• thermoformability of the new material is proven by the following viscoelastic properties:
• Perlon fabric provides the medium modulus AIREX® PCV provides the lowest modulus
• Carbon filaments are the constituents which increase the rigidity of the laminate by raising the glass transition temperature alpha.
• Tandelta indicates its good ability to dissipate bending stresses.
• PVC increases the impact resistance and the thermoformability of the laminate.
• PVC introduces two transition zones, namely:
• Table 3 gives the viscoelastic properties of the laminated material according to Examples 3 and 4
• Perlon and PVC of relatively large thickness reduce the rigidity and favorite the thermoformability by lowering Tg alpha and Tfl.
• the insertion of carbon filaments in the middle layer increases its rigidity.
• Tg beta is moved to a higher temperature.
• the density of the laminate ⁇ 1 is significantly lower than that of the resin / carbon filament products which is between 1.2 and 1.4.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Composite Materials (AREA)
• Mechanical Engineering (AREA)
• Laminated Bodies (AREA)

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• 1990
  • 1990-09-26 EP EP90914117A patent/EP0446325A1/de not_active Withdrawn
  • 1990-09-26 WO PCT/CH1990/000226 patent/WO1991004852A1/fr not_active Ceased
  • 1990-09-26 CA CA002042410A patent/CA2042410A1/fr not_active Abandoned

Non-Patent Citations (1)

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