Facility for the continuous production of an elongate composite element having an oval cross-section, and facility for the production of a strip comprising a plurality of elongate composite elements

Abstract

The invention relates to a facility (100) for the continuous production of an elongate composite element (EF) comprising a bundle of multifilament fibres impregnated with a composition based on a polymerisable material, the facility (100) comprising a device (120) for the mechanical deformation of a monofilament (E2) which was pre-polymerised in a first radiating device (117), which deformation device is arranged upstream of a second radiating device (118) in the forward travel direction of the bundle of multifilament fibres and is configured to deform the pre-polymerised monofilament (E2) and to give the cross-section of the pre-polymerised monofilament (E2) an oval shape.

Description

[0001] DESCRIPTION

[0002] TITLE: Installation for the continuous production of an elongated composite element of oval section and installation for the production of a ribbon comprising a plurality of elongated composite elements

[0003] The present invention relates to the field of reinforcements based on composite materials.

[0004] More particularly, the present invention relates to the continuous manufacture of elongated composite materials produced by impregnation of a polymerizable composition of multifilament fibers.

[0005] More particularly, the present invention relates to an installation for manufacturing composites in the form of single strands comprising continuous, unidirectional multifilament fibers embedded in a polymerizable resin.

[0006] The present invention relates more particularly, but not exclusively, to the manufacture of single strands of glass resin composite, acronym "CVR", having high mechanical properties.

[0007] Such elongated composite materials can be used in the form of composite reinforcements which can be used, in particular, for the reinforcement of semi-finished products or finished rubber articles such as vehicle tires, for example of the pneumatic or non-pneumatic type, or in concrete reinforcement applications.

[0008] Generally, with reference to figure 1, a device 1 for manufacturing a single strand of glass-resin composite comprises one or more reels 10 containing glass fibers 11 in the form of multifilaments and continuously unwound by driving along the arrow F by a driving means (not shown), so as to produce a rectilinear arrangement 12 of these fibers 11.

[0009] The arrangement 12 then passes through a vacuum chamber 13 arranged between an inlet nozzle 13a and a separation nozzle 13b and an impregnation chamber 14 downstream of the separation nozzle 13b and filled with impregnation composition 15 based on a curable resin. The device 1 further comprises a calibration die

[0010] 16 at the outlet of the impregnation chamber 14 so as to obtain a single strand 17 and a radiation device 18 comprising, for example, a protection tube 18a through which the composite single strand circulates

[0011] 17 and a plurality of UV and / or IR irradiators 18b in line in order to obtain a polymerized monostrand 19.

[0012] Controlling the geometry of the reinforcement is a key aspect to facilitate the manufacturing process of the final object and maximize its performance.

[0013] Traditionally, known composite monostrands have a circular cross-section and are composed of continuous glass fibers impregnated with a polymerizable material, preferably photo-polymerizable.

[0014] We know the document EP 1 174 250 - Al which describes a process for the continuous manufacture of CVR monostrands comprising the following steps:

[0015] - making an arrangement of glass fibers and driving this arrangement in a direction of advancement;

[0016] - degas the fiber arrangement by the action of vacuum in a vacuum chamber;

[0017] - at the outlet of the vacuum chamber, after degassing, pass through an impregnation chamber filled with resin so as to impregnate said arrangement of fibers with a resin in the liquid state to obtain an impregnation containing the fibers and the resin;

[0018] - passing said impregnated material through a calibration die having a predefined surface section and shape, to impose a single-strand shape on it; and

[0019] - downstream of the calibration line, in an irradiation chamber, stabilize, solidify the single strand by photopolymerization of the resin in a UV and / or IR radiation device.

[0020] It is known to integrate the composite monostrands thus obtained into a thermoplastic matrix in order to obtain tapes containing several composite monostrands. These tapes are then used in an automatic tape laying process, called "automatic tape laying" in English terms.

[0021] However, due to the circular shape of the composite monostrands, the performance of such a tape in tension in the direction parallel to the composite monostrands is not satisfactory.

[0022] Thus, there is a need to remedy the aforementioned drawbacks. The invention aims to improve the tensile performance of ribbons comprising a plurality of composite monostrands trapped in a thermoplastic matrix, while minimizing the thickness of the ribbon and its weight.

[0023] The present invention relates to an installation for the continuous manufacture of an elongated composite element comprising a bundle of multifilament fibers impregnated with a composition based on a polymerizable material.

[0024] The installation comprises an installation for the continuous production of an elongated composite element comprising a bundle of multifilament fibers impregnated with a composition based on a polymerizable material, the installation comprising, in the direction of advance of the bundle of multifilament fibers:

[0025] - a feeding device configured to form a bundle of multifilament fibers;

[0026] - a degassing chamber for the multifilament fiber bundle;

[0027] - an impregnation chamber filled with a composition based on a polymerizable material and configured to impregnate said degassed bundle of multifilament fibers with said composition and form an impregnated single strand, said impregnation chamber being located downstream of the degassing chamber in the direction of advancement of the bundle of multifilament fibers.

[0028] The installation also includes:

[0029] - a first radiation device through which the monostrand impregnated with polymerizable material circulates and configured to carry out a partial polymerization of said impregnated monostrand to form a pre-polymerized monostrand; at least - a second radiation device, separate and distinct from the first radiation device configured to form a final composite monostrand, and

[0030] - a translational drive device configured to drive the bundle of multifilament fibers in translation and to apply tension to said bundle of multifilament fibers.

[0031] The installation comprises a device for mechanically deforming the pre-polymerized monostrand arranged between the first radiation device and the second radiation device in the direction of advancement of the bundle of multifilament fibers, said device for mechanically deforming the pre-polymerized monostrand being configured to plastically deform the pre-polymerized monostrand and give an oval shape to the section of said pre-polymerized monostrand to form a deformed monostrand.

[0032] Thus, the mechanically deformed single strand circulates through the second radiation device in order to carry out a final polymerization of said deformed single strand to form a final composite single strand.

[0033] The second radiation device is configured to perform final polymerization of the pre-polymerized monostrand.

[0034] By "partial polymerization or pre-polymerization" is meant that the degree of polymerization of the multifilament fiber bundle has reached between 35% and 65% of complete polymerization.

[0035] Without limitation, the degree of polymerization can be assessed using a “DSC” type measuring instrument, an acronym for “Differential Scanning Calorimetry” in English terms.

[0036] The pre-polymerization step makes it possible to obtain a pre-polymerized, non-sticky single strand, capable of no longer deforming in the free state while being malleable to be deformed under mechanical stress.

[0037] The so-called "complete" or "final" polymerization of the composite is obtained when the degree of polymerization of the polymerizable material is close to 100%, preferably greater than or equal to 95% of the complete polymerization. The device for mechanical deformation of the pre-polymerized single strand is configured to plastically deform the pre-polymerized single strand and obtain a deformed single strand.

[0038] By "plastic deformation" we mean a non-reversible deformation.

[0039] Thanks to the mechanical deformation device, it is possible to give an oval shape to the section of the single strand before the final polymerization.

[0040] The oval shape helps reduce the amount of thermoplastic material needed to make the tape, while minimizing its thickness.

[0041] The oval shape also helps improve the tensile performance of composite single strands in the direction parallel to the composite single strands.

[0042] Alternatively, it could be envisaged to add a third light source with ultraviolet radiation arranged between the additional radiation device and the final radiation device.

[0043] By "elongated composite element" is meant a very long composite element comprising a bundle of multifilament fibers embedded in a composition based on a polymerizable material, which is manufactured continuously from one or more supply reels of multifilament fibers to form a bundle which is driven in translation to successively impregnate its fibers with polymerizable material and polymerize the material as the bundle moves.

[0044] By “multifilament fiber” is meant a fiber which comprises several elementary filaments arranged side by side to form a bundle whose elementary fibers are unidirectional while being substantially parallel to each other.

[0045] Multifilament fibers can be chosen from the group consisting of glass, carbon, silica, ceramic, flax, hemp, basalt, cellulose, etc. fibers. These multifilament fibers are used to produce elongated composites made by impregnating the multifilament fibers with a polymerizable composition.

[0046] The polymerizable material may be of the thermosetting type, preferably thermocrosslinkable, preferably of the vinylester type. By polymerizable material is meant a material comprising, by weight, more than 50%, preferably more than 75%, of organic matter, and even more preferably more than 90% of organic matter.

[0047] Thus, this material may be a thermopolymerizable polymeric material, for example based on unsaturated polyester, polyepoxide, phenolic derivative, or aminoplast. Preferably, the polymerizable material is crosslinked.

[0048] For example, the polymerizable material is a resin that can be crosslinked by ionizing radiation, and the final polymerization can be easily triggered and controlled by means of an ionizing treatment, for example of the UV type.

[0049] The glass transition temperature Tg of the polymerizable material is preferably greater than or equal to 130°C, for example greater than 170°C, preferably greater than or equal to 180°C.

[0050] For example, the final composite element is a single strand comprising multifilament fibers embedded in a polymerizable material, such as a thermosetting resin.

[0051] The final composite monostrand can take an oval shape with a width between 0.75mm and 2.5mm.

[0052] The elementary filaments, for example, each have an average diameter of between 5 pm and 30 pm.

[0053] The drive device is, for example, of the type comprising a motorized traction drum for winding the composite element around its axis or comprising two motorized drums facing each other, spaced apart by a corresponding distance at least equal to the thickness of the composite element and which rotate in opposite directions to drive the final composite element, by friction, in a translational movement, making it pass into the space located between the two drums. Alternatively, any drive device could be used to set the bundle of multifilament fibers in motion in a direction of advance.

[0054] Advantageously, the mechanical deformation device comprises at least two first end rollers and a central roller located axially between the two end rollers and offset from said end rollers vertically by a distance along the vertical axis perpendicular to the direction of advancement, said rollers, and in particular their external cylindrical surface, being in partial contact with the pre-polymerized single strand.

[0055] The mechanical deformation device comprises three rollers on which the single strand impregnated and pre-polymerized by the first UV source is deformed thanks to the tension applied to said single strand by the drive device and the vertical offset of the central roller.

[0056] The width / height aspect ratio is changed by varying the height of the central roller.

[0057] The polymerization of the polymerizable material is then completed when it passes through the UV lamps placed after the mechanical deformation device.

[0058] The pre-polymerized monostrand is intended to come into contact with the end rollers from below and with the central roller from above.

[0059] For example, the mechanical deformation device comprises a fixed structure, said rollers being integral with said fixed structure, the end rollers being fixed in translation relative to said fixed structure and the central roller is movable in translation along the vertical axis.

[0060] The rollers have, for example, a diameter between 30mm and 70mm, preferably equal to 50mm.

[0061] The central roller is preferably mounted on an axle sliding in a vertical groove made on the fixed structure.

[0062] According to one embodiment, the rollers are movable in rotation along a transverse axis perpendicular to the axis of advancement and to the vertical axis relative to the fixed structure. For example, the two end rollers are located on the same first axis parallel to the longitudinal axis of advancement.

[0063] The height between the axis of the central roller and the axis of the end rollers is, for example, between 4mm and 40mm, preferably between 10mm and 30mm.

[0064] According to one embodiment, the installation comprises at least one instrument or scraper associated with one of the rollers and configured to scrape the polymerizable material deposited on the outer surface of the corresponding roller.

[0065] The scraper is advantageously fixed on the axis of rotation of the corresponding roller and is fixed in rotation relative to it.

[0066] The scraper allows continuous cleaning of the rollers, and prevents modification of the contact area between the pre-polymerized single strand and the outer surface of the roller, and consequently deformation of said single strand.

[0067] The mechanical deformation device comprises, for example, two scrapers each associated respectively with the central roller and the output end roller.

[0068] Alternatively, it could be provided that the deformation device comprises three scrapers each associated with one of the rollers or that it comprises only one scraper associated with one of the central roller or the output end roller.

[0069] The scraper is in the form of a thin blade, preferably metallic, directed towards the outer surface of the corresponding roller, in the opposite direction to the direction of rotation of the roller.

[0070] According to one embodiment, the installation comprises a heating device associated with the impregnation chamber and configured to heat the polymerizable material present in said impregnation chamber to a temperature between 50°C and 95°C, preferably between 60°C and 80°C.

[0071] Alternatively, it could be provided that the installation does not include such a heating device. According to one embodiment, the first radiation device comprises a first light source with ultraviolet radiation, with the acronym UV.

[0072] According to one embodiment, the first radiation device comprises a first light source which combines ultraviolet radiation, acronym UV, and infrared radiation, acronym IR.

[0073] The exposure time of the impregnated single strand to the first light source with combined ultraviolet and infrared radiation is between 0.1 s and 1.5 s, preferably between 0.4 s and 0.7 s.

[0074] The power of the first light source with combined ultraviolet and infrared radiation is between 2kW and 14kW, preferably between 4kW and 7kW.

[0075] According to one embodiment, the first light source comprises a plurality of light-emitting diodes configured to emit only monochromatic ultraviolet radiation with a wavelength between 200nm and 405nm, preferably between 365nm and 405nm. In this case, the LEDs are combined with infrared radiation.

[0076] According to another embodiment, the first light source comprises a plurality of mercury vapor lamps configured to emit broad spectrum ultraviolet (UV) radiation, infrared radiation, and visible light. The mercury vapor lamps may be combined with infrared radiation with an infrared radiation wavelength between 1 pm and 3 pm.

[0077] According to one embodiment, the second radiation device comprises a second light source with combined ultraviolet and infrared radiation to complete the polymerization of the deformed single strand.

[0078] The exposure time of the deformed single strand to the second light source combining ultraviolet and infrared rays is between 1 s and 6 s, preferably between 1.5 s and 3 s.

[0079] The power of the second UV and infrared light source is between 100kW and 60kW, preferably between 20kW and 40kW. According to a variant, the second light source comprises a plurality of light-emitting diodes, acronym LED, preferably directed radially towards the deformed single strand, the available wavelengths of which are between 200nm and 405nm, preferably between 365nm and 405nm. In this case, the LEDs are combined with infrared radiation.

[0080] According to another variant, the second light source could comprise a plurality of mercury vapor lamps, the exposure time of the deformed single strand of which is between 1 s and 4 s, preferably between 1.5 s and 2 s, at a power of between 1 0kW and 60kW, preferably between 20kW and 40kW.

[0081] Alternatively, the second light source could include a plurality of mercury vapor lamps configured to emit broad spectrum ultraviolet (UV) radiation, infrared radiation, and visible light. The mercury vapor lamps may be combined with infrared radiation with an infrared radiation wavelength between 1 pm and 3 pm.

[0082] According to yet another variant, it could be provided that the second radiation device comprises an infrared radiation light source configured to emit only infrared radiation, with a wavelength between 1 pm and 3 pm.

[0083] In this case, the duration of exposure of the deformed single strand to the second light source combining infrared radiation alone is between 2s and 8s, preferably between 3s and 4s and the power of this second infrared light source is between 100kW and 60kW, preferably between 20kW and 40kW.

[0084] According to a second aspect, the invention relates to an installation for manufacturing a ribbon comprising the installation for manufacturing a composite element as described above and a module for manufacturing a ribbon configured to manufacture a ribbon from a plurality of composite elements manufactured by the installation and from a matrix made of polymerizable material, such as a thermoplastic resin. Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0085] [Fig. l] very schematically represents an installation for manufacturing a composite element according to the state of the art;

[0086] [Fig.2] very schematically represents an installation for manufacturing a composite element according to one embodiment of the invention;

[0087] [Fig.3] very schematically represents a mechanical deformation device of the installation of figure 2;

[0088] [Fig.4] illustrates a detail view of a roller of the mechanical deformation device of Figure 3;

[0089] [Fig.5] is a graph illustrating the variation of the aspect ratio as a function of the power of the ultraviolet radiation lamp of the installation of Figure 2 and the production speed according to a Bayesian type mathematical model;

[0090] [Fig.6] is a graph illustrating the variation of the aspect ratio as a function of the roller height and the production speed, according to a Bayesian type model; and represents an installation for manufacturing a ribbon comprising composite monostrands from the installation of figure 2 embedded in a thermoplastic matrix.

[0091] Figure 2 schematically illustrates an installation 100 for manufacturing a very long, elongated EF composite element.

[0092] By "elongated composite element" is meant a very long composite element comprising a bundle of multifilament fibers embedded in a composition based on a polymerizable material, which is manufactured continuously from one or more supply reels of multifilament fibers Fi_0 to form a bundle which is driven in translation along the arrow F to successively impregnate its fibers with polymerizable material and polymerize the material as the bundle moves.

[0093] By “multifilament fiber” is meant a fiber which comprises several elementary filaments Fi arranged side by side to form a bundle whose elementary fibers are unidirectional while being substantially parallel to each other.

[0094] Multifilament fibers can be chosen from the group consisting of glass, carbon, silica, ceramic, flax, hemp, basalt, cellulose, etc. fibers. These multifilament fibers are used to produce elongated composites made by impregnating the multifilament fibers with a polymerizable composition.

[0095] The polymerizable material may be of the thermosetting type, preferably thermocrosslinkable, preferably of the vinylester type. By polymerizable material is meant a material comprising, by weight, more than 50%, preferably more than 75%, of organic matter and even more preferably more than 90% of organic matter.

[0096] Thus, this material may be a thermopolymerizable polymeric material, for example based on unsaturated polyester, polyepoxide, phenolic derivative, or aminoplast. Preferably, the polymerizable material is crosslinked.

[0097] For example, the polymerizable material is a resin that can be crosslinked by ionizing radiation, and the final polymerization can be easily triggered and controlled by means of an ionizing treatment, for example of the UV type.

[0098] The glass transition temperature Tg of the polymerizable material is preferably greater than or equal to 130°C, for example greater than 170°C, preferably greater than or equal to 180°C. In the example illustrated in the figures, the composite element EF is a single strand comprising multifilament fibers embedded in a polymerizable material, such as a thermosetting resin.

[0099] The EF composite monofilament can take an oval shape with a width between 0.75mm and 2.5mm.

[0100] The elementary filaments, for example, each have an average diameter of between 5 pm and 30 pm.

[0101] As illustrated in Figure 2, the manufacturing installation 100 comprises, in the direction of advancement of the bundle of multifilament fibers according to arrow F:

[0102] - a supply device 1 1 1 comprising here one or more reels 1 12 for supplying elementary filaments Fi_0 to form a bundle of multifilament fibers E0,

[0103] - a vacuum chamber 113 or degassing chamber arranged between an inlet nozzle 113a and a separation nozzle 113b;

[0104] - an impregnation chamber 114 downstream of the vacuum chamber 113 and in particular of the separation nozzle 113b and filled with an impregnation composition 115 based on a polymerizable material;

[0105] - a calibration die 1 16 at the outlet of the impregnation chamber 1 14 so as to obtain a single strand E l impregnated with polymerizable material;

[0106] - a first radiation device 117 through which circulates the single strand E1 impregnated with polymerizable material and configured to carry out a partial or intermediate polymerization to form a pre-polymerized single strand E2;

[0107] - a mechanical deformation device 120 of the pre-polymerized single strand E2 arranged downstream of the first radiation device 117 and configured to give an oval shape to the section of said pre-polymerized single strand E2 and form a deformed single strand E3;

[0108] - a second radiation device 1 18 or final radiation device, distinct from the first radiation device 1 17, through which the deformed monostrand E3 circulates and configured to carry out a final polymerization to form a final composite monostrand EF; and - a translational drive device D according to arrow F configured to drive the bundle of multifilament fibers in translation to successively carry out degassing, impregnation of polymerizable material of its fibers and polymerization of the material as the bundle moves.

[0109] The vacuum chamber 113, the impregnation chamber 114, the calibration die 116, the first radiation device 117 and the second radiation device 118 are arranged along the same axis corresponding to the longitudinal axis X-X' of the installation 100 in the longitudinal direction X.

[0110] Generally, the fibers are delivered by one or more reels 1 12, called "rovings" in Anglo-Saxon terms. The bundle, coming from the feeding device 1 1 1 , passes through the installation, advancing in the direction of the arrow F, being set in motion by the drive device D located at the output of the device.

[0111] Each spool 112 can supply a multifilament fiber. If the installation 100 comprises two multifilament fibers, the supply device 111 comprises two spools.

[0112] The drive device D is, for example, of the type comprising a motorized traction drum for winding the composite element around its axis or comprising two motorized drums facing each other, spaced apart by a corresponding distance at least equal to the thickness of the composite element and which rotate in opposite directions to drive the composite element EF, by friction, in a translational movement, making it pass into the space located between the two drums. Alternatively, any drive device could be used to set the bundle of multifilament fibers in motion in a direction of advance.

[0113] The vacuum chamber 113 is, in a manner known per se, delimited by a rigid inlet nozzle 113a, provided with one or more through orifices and a rigid separation nozzle 113b, also provided with one or more through orifices located axially opposite the orifice(s) of the inlet nozzle 113a.

[0114] The bundle of multifilament fibers EO is introduced into the vacuum chamber 1 13 by passing it through the orifice of the inlet nozzle 1 13a and exits through the through orifice(s) of the separation nozzle 1 13b.

[0115] The vacuum chamber 1 13 is connected to a vacuum pump (not shown) which maintains a pressure level of approximately 0. lbar in the vacuum chamber 1 13 , despite the passage of the bundle of multifilament fibers EO through the orifice(s) having a diameter greater than that of the bundle of multifilament fibers EO which passes through them.

[0116] The vacuum chamber 1 13 allows the bundle of EO multifilament fibers to be degassed by the action of the vacuum and thus to reinforce the effectiveness of the subsequent impregnation and above all to guarantee the absence of bubbles inside the final composite monostrand.

[0117] After passing through the vacuum chamber 1 13 , the bundle of multifilament fibers EO enters an impregnation chamber 1 14 which is completely full of polymerizable impregnation material, therefore free of air.

[0118] The impregnation chamber 1 14 is an airtight enclosure, delimited by the separation nozzle 1 13b and a rigid calibration nozzle 1 16, also provided with a through orifice located axially opposite the orifice of the separation nozzle 1 13b.

[0119] The impregnation chamber 114 is supplied with polymerizable material 115 coming from an external reservoir (not shown) via an inlet pipe 115a, here located in the upper part of said impregnation chamber 114.

[0120] The impregnation chamber 114 may also comprise, for example on its lower part, a discharge pipe (not shown) for the polymerizable material.

[0121] The impregnation chamber 114 is completely filled with polymerizable material so that the bundle of multifilament fibers exiting the vacuum chamber 113 and passing through it in a linear path is completely impregnated with polymerizable material.

[0122] The impregnation chamber 114 is, here, associated with a heating device 114b configured to heat the polymerizable material to a temperature between 50°C and 95°C, preferably between 60°C and 80°C.

[0123] Thus, the impregnated bundle of multifilament fibers leaves the impregnation chamber 1 14 at a temperature between 50°C and 95°C, preferably between 60°C and 80°C before passing through the polymerization devices 1 17, 1 18.

[0124] Alternatively, such a heating device 1 14b could not be provided.

[0125] The calibration die 1 16 here comprises a calibration nozzle configured to shape the bundle of multifilament fibers exiting the impregnation chamber 1 14 to form an impregnated single strand E l .

[0126] The first radiation device 1 17 comprises a first light source 1 17a which combines ultraviolet radiation 1 17a, acronym UV, and infrared radiation, acronym IR.

[0127] The exposure time of the impregnated single strand E l to the first light source with combined ultraviolet / infrared radiation is between 0.1 s and 1.5 s, preferably between 0.4 s and 0.7 s.

[0128] The power of the first light source with combined ultraviolet / infrared radiation is between 2 kW and 14 kW, preferably between 4 kW and 7 kW.

[0129] For example, the first light source comprises a plurality of light-emitting diodes (not shown), acronym LED, preferably directed radially towards the impregnated single strand E l .

[0130] For example, the power of LED's is between 2kW and 14 kW, preferably between 4 kW and 7 kW.

[0131] According to yet another variant, the first light source with radiation is configured to emit only monochromatic ultraviolet radiation, for example via LEDs, the available wavelengths of which are as follows: 365, 385, 395, 405nm, and more generally between 200nm and 405nm.

[0132] In a non-limiting manner, the first radiation device 117 may comprise a guide tube (not referenced) for the impregnated single strand E1 which enters the first radiation device 117. The protection tube is, for example, made of quartz glass, through which the single strand circulates during formation, this tube may be traversed by a current of inert gas, preferably nitrogen.

[0133] The first 1 17a LED ultraviolet light source therefore makes it possible to emit radial radiation on the impregnated single strand E l, with or without reflectors to optimize irradiation.

[0134] According to yet another variation, the first light source 117a could comprise a plurality of mercury vapor lamps configured to emit broad spectrum ultraviolet radiation (UV), infrared radiation, and visible light.

[0135] The first radiation device 117 is configured to partially polymerize or pre-polymerize the impregnated monostrand E1 and deliver a pre-polymerized impregnated multifilament fiber monostrand E2.

[0136] By "partial polymerization or pre-polymerization" is meant that the degree of polymerization of the multifilament fiber bundle has reached between 35% and 65% of complete polymerization.

[0137] The pre-polymerization step makes it possible to obtain a pre-polymerized, non-sticky single strand of fibers, capable of no longer deforming in the free state while being malleable to be deformed under mechanical stress.

[0138] The second radiation device 1 18 or final radiation device comprises a second light source 1 18a with combined ultraviolet and infrared radiation or infrared radiation alone configured to complete the polymerization of the pre-polymerized and deformed impregnated multifilament fiber bundle, called deformed monostrand E3. Complete polymerization of the composite is obtained when the degree of polymerization of the polymerizable material is close to 100%, preferably greater than or equal to 95%.

[0139] The exposure time of the deformed single strand E3 to the second light source combining ultraviolet and infrared rays is between 1 s and 6 s, preferably between 1.5 s and 3 s.

[0140] The power of the second light source with combined UV and infrared radiation is between 10 kW and 60 kW, preferably between 20 kW and 40 kW.

[0141] According to a variant, the second light source comprises a plurality of light-emitting diodes (not shown), acronym LED, preferably directed radially towards the deformed single strand E3, the available wavelengths of which are between 200nm and 405nm, preferably between 365nm and 405nm.

[0142] According to another variant, the second light source 118a could comprise a plurality of mercury vapor lamps, the exposure time of the deformed single strand of which is between 1 s and 4 s, preferably between 1.5 s and 2 s, at a power of between 10 kW and 60 kW, preferably between 20 kW and 40 kW.

[0143] Alternatively, the second light source 118a could comprise a plurality of mercury vapor lamps configured to emit broad spectrum ultraviolet radiation (UV), infrared radiation and visible light and a plurality of lamps with an infrared radiation wavelength between 1 pm and 3 pm.

[0144] According to yet another variant, the second light source could be solely infrared radiation. The second radiation device in this case comprises a solely infrared radiation light source configured to emit only infrared radiation, with a wavelength between 1 pm and 3 pm.

[0145] In this case, the duration of exposure of the deformed single strand E3 to the second light source combining infrared radiation alone is between 2s and 8s, preferably between 3s and 4s and the power of this second infrared light source is between 100kW and 60kW, preferably between 20kW and 40kW.

[0146] Alternatively, a third radiation device with a light source with combined ultraviolet and infrared radiation or infrared radiation alone could be provided between the mechanical deformation device 120 and the second radiation device 118.

[0147] The mechanical deformation device 120 of the pre-polymerized E2 single strand is illustrated in detail with reference to FIG. 3.

[0148] The mechanical deformation device 120 of the pre-polymerized E2 single strand is configured to plastically deform the pre-polymerized E2 single strand and obtain a deformed E3 single strand.

[0149] As illustrated, the mechanical deformation device 120 of the pre-polymerized monostrand E2 comprises a fixed structure 121 and three guide rollers 122, 124, 126 integral with said fixed structure 121 and movable in rotation relative to said fixed structure 21 along a transverse axis Y perpendicular to the longitudinal advancement axis X-X'.

[0150] The two end rollers 122, 126 are fixed in translation along the vertical axis Z, and the central roller 124, located axially between the two end rollers 122, 126, is movable in translation along the vertical axis Z.

[0151] The two end rollers 122, 126 are located on the same first axis X2 parallel to the longitudinal advance axis X-X' and the central roller 124 is located on a second axis X3 parallel to the longitudinal advance axis X-X' and vertically offset from the first axis X2 by a height H.

[0152] The central roller 124 is, here, axially located between the two end rollers 122, 126. Alternatively, it could be provided that the central roller 124 is axially closer to the inlet end roller 122 than to the outlet end roller 126 or vice versa.

[0153] Each roller 122, 124, 126 comprises a cylindrical body having a cylindrical outer surface 122a, 124a, 126a in partial contact with the pre-polymerized monostrand E2. The pre-polymerized monostrand E2 is intended to come into contact with the end rollers 122, 126 from below and with the central roller 126 from above.

[0154] Alternatively, a structural inversion could be provided in which the central roller 124 is vertically offset above the end rollers 122, 126. In this configuration, the pre-polymerized monostrand E2 is intended to come into contact with the end rollers 122, 126 from above and with the central roller 126 from below.

[0155] The cylindrical body of each roller 122, 124, 126 comprises a cylindrical inner surface 122b, 124b, 126b rotatably mounted on the fixed structure 121, for example via a rolling bearing 122c, 124c, 126c.

[0156] With reference to figure 4, the axis 127 of the central roller 124 is mounted in a vertical groove 128 making it possible to adjust the height H of the second axis X3 of the central roller 124 and thus to give an oval shape to the pre-polymerized single strand E2.

[0157] The height H between the second axis X3 and the first axis X2 is between 3mm and 40mm, preferably between 10mm and 30mm.

[0158] As illustrated in Figure 4, the mechanical deformation device 120 includes an instrument or scraper 129 configured to scrape the polymerizable material deposited on the outer surface 124a of the central roller 124.

[0159] The scraper 129 is fixed on the axis of rotation of the central roller 124 and is fixed in rotation relative to the latter.

[0160] The scraper comprises a thin blade 129a, preferably metallic, directed towards the outer surface of the corresponding roller, in the direction opposite to the direction of rotation of the roller.

[0161] The scraper 129 allows the rollers to be continuously cleaned, and prevents modification of the contact area between the pre-polymerized single strand and the outer surface of the roller, and consequently deformation of said single strand.

[0162] The mechanical deformation device 120 here comprises two scrapers each associated respectively with the central roller 124 and with the outlet end roller 126. Alternatively, it could be provided that the deformation device comprises three scrapers each associated with one of the rollers 122, 124, 126 or that it comprises only one scraper associated with one of the central roller 124 or the outlet end roller 126.

[0163] The mechanical deformation device 120 of the pre-polymerized E2 monostrand being configured to give an oval shape to the section of said pre-polymerized E2 monostrand.

[0164] An "oval" shape means a non-circular, elliptical, or oblong shape with a width-to-height ratio other than 1.

[0165] The width / height aspect ratio of the monostrand is modified by varying the height H of the central roller 124.

[0166] Two graphs illustrating the aspect ratio are shown in Figures 5 and 6.

[0167] In Figure 5, the graph illustrates the variation of the aspect ratio R along the Z axis as a function of the power of the first ultraviolet light source 1 18a along the X axis and the production speed V along the Y axis according to a Bayesian type mathematical model.

[0168] The larger the aspect ratio R, the darker the shade of gray.

[0169] In Figure 6, the graph illustrates the variation of the aspect ratio R along the Z axis as a function of the height H of the central roller 124 along the abscissa axis X and the production speed V along the ordinate axis Y, according to a Bayesian type mathematical model.

[0170] It turns out that there is an optimal set of parameters.

[0171] Figure 7 illustrates an installation 200 for manufacturing a “Tape” ribbon comprising the installation 100 for manufacturing a composite element EL as described with reference to Figures 2 to 4 and a module 210 for manufacturing a “Tape” ribbon configured to manufacture a ribbon from a plurality of composite elements (EE)n manufactured by the installation 100 and a matrix made of polymerizable material (not shown), such as a thermoplastic resin. The installation according to the invention makes it possible to continuously produce a deformed composite monostrand that does not require post-treatment.

[0172] Such an installation can easily be implemented on all existing composite reinforcement production lines. Thanks to the mechanical deformation device, it is possible to give an oval shape to the section of the single strand before final polymerization.

[0173] The oval shape helps reduce the amount of thermoplastic material needed to make the tape, while minimizing its thickness.

[0174] The oval shape also helps improve the tensile performance of composite single strands in the direction parallel to the composite single strands.

[0175] The mechanical deformation device according to the invention is easily installed on a production line for composite monostrands of known circular section, after the first UV radiation device.

Claims

CLAIMS 1. Installation (100) for the continuous manufacture of an elongated composite element (EF) comprising a bundle of multifilament fibers impregnated with a composition based on a polymerizable material, the installation (100) comprising, in the direction of advance (X-X') of the bundle of multifilament fibers: - a feed device (111) configured to form a bundle of multifilament fibers (E0); a degassing chamber (113) for the bundle of multifilament fibers (E0); - an impregnation chamber (114) filled with a composition based on a polymerizable material and configured to impregnate said degassed bundle of multifilament fibers (E0) with said composition and form an impregnated single strand (E1), said impregnation chamber (114) being located downstream of the degassing chamber in the direction of advancement of the bundle of multifilament fibers; and - a first radiation device (117) through which the impregnated monostrand (E1) of polymerizable material circulates and configured to carry out a partial polymerization to form a pre-polymerized monostrand (E2); and at least - a second radiation device (118), separate and distinct from the first radiation device (117) configured to form a final composite monostrand (EF), and - a translational drive device (D) configured to drive the bundle of multifilament fibers in translation and to apply tension to said bundle of multifilament fibers, characterized in that it comprises a device (120) for mechanically deforming the pre-polymerized single strand (E2) arranged between the first radiation device (117) and the second radiation device (118) in the direction of advancement of the bundle of multifilament fibers, said device (120) for mechanically deforming the pre-polymerized single strand (E2) being configured to plastically deform the pre-polymerized single strand (E2) and confer a shape oval to the section of said pre-polymerized monostrand (E2) and form a deformed monostrand (E3), characterized in that the mechanical deformation device (120) comprises at least two first end rollers (122, 126) and a central roller (124) located axially between the two end rollers (122, 126) and offset from said end rollers (122, 126) vertically by a distance (H) along the vertical axis (Z) perpendicular to the direction of advance (X-X'), said rollers (122, 124, 126) being in partial contact with the pre-polymerized monostrand (E2), the monostrand impregnated and pre-polymerized by the first UV source being configured to deform thanks to the tension applied to said monostrand by the drive device and the vertical offset of the central roller.

2. Installation (100) according to claim 1, in which the mechanical deformation device (120) comprises a fixed structure 121, said rollers (122, 124, 126) being integral with said fixed structure (121), the end rollers (122, 126) being fixed in translation relative to said fixed structure (121) and the central roller (124) is movable in translation along the vertical axis (Z).

3. Installation (100) according to claim 2, in which the central roller (124) is mounted on an axis (127) sliding in a vertical groove (128) made on the fixed structure (121).

4. Installation (100) according to claim 2 or 3, in which the rollers (122, 124, 126) are movable in rotation along a transverse axis (Y) perpendicular to the longitudinal advancement axis (X-X') and to the vertical axis (Z) relative to the fixed structure (121).

5. Installation (100) according to any one of the preceding claims, in which the two end rollers (122, 126) are located on the same first axis (X2) parallel to the longitudinal advance axis (X-X').

6. Installation (100) according to any one of the preceding claims, in which the height (H) between the axis of the central roller (124) and the axis of the end rollers (122, 124) is between 4mm and 40mm, preferably between 10mm and 30mm.

7. Installation (100) according to any one of the preceding claims, comprising at least one scraper (129) associated with one of the rollers (122, 124, 126) and configured to scrape the polymerizable material deposited on the outer surface (122a, 124a, 126a) of the corresponding roller (122, 124, 126).

8. Installation (100) according to any one of the preceding claims, comprising a heating device (114b) associated with the impregnation chamber (114) and configured to heat the polymerizable material present in said impregnation chamber (114) to a temperature between 50°C and 95°C, preferably from 60°C to 80°C.

9. Installation (100) according to any one of the preceding claims, in which the first radiation device (117) comprises a first light source (117a) with ultraviolet radiation.

10. Installation (100) according to any one of the preceding claims, in which the first light source (117a) with ultraviolet radiation comprises a plurality of light-emitting diodes configured to emit only monochromatic ultraviolet radiation with a wavelength between 200nm and 405nm. 1 1. Installation (100) according to claim 10, in which the first light source (1 17a) with ultraviolet radiation further comprises infrared radiation.

12. Installation (100) according to any one of the preceding claims, in which the first light source (117a) with ultraviolet radiation comprises a plurality of mercury vapor lamps configured to emit broad spectrum ultraviolet radiation UV, infrared radiation and visible light.

13. Installation (100) according to any one of the preceding claims, in which the second radiation device (118) comprises a second light source (118a) with combined ultraviolet and infrared radiation or infrared radiation alone to complete the polymerization of the deformed single strand (E3).

14. Installation (200) for manufacturing a tape comprising the installation for manufacturing a composite element (EF) according to any one of the preceding claims and a module (210) for manufacturing a tape (Tape) configured to manufacture a tape from a plurality of composite elements (EF) manufactured by the installation (100) and a matrix made of polymerizable material.

Images