Facility for the continuous manufacture of an elongate composite element

Abstract

The invention relates to a facility (1) for the continuous manufacture of an elongate composite element (EF) comprising a multifilament fibre bundle impregnated with a composition based on a polymerisable material, the facility (1) comprising an impregnation chamber (14) filled with a composition based on a polymerisable material and configured to impregnate a multifilament fibre bundle (E0) with the composition and to form a first impregnated monofilament (E1). The impregnation chamber (14) comprises at least one pressure-varying device (17) configured to produce a pressure variation along the longitudinal axis (X-X') of the facility (1). The facility comprises a first radiation device (18) for pre-polymerising the first impregnated monofilament (E1) and forming a pre-polymerised monofilament (E2), and a second radiation device (18) for carrying out a final polymerisation of the pre-polymerised monofilament (E2).

Description

[0001] DESCRIPTION

[0002] Title of the invention: Installation for the continuous manufacturing of a long, thin composite element

[0003] The present invention relates to the field of continuous manufacturing of elongated composite materials made by impregnating multifilamentary fibers with a polymerizable composition.

[0004] More particularly, the present invention relates to an installation and a method for manufacturing composites in the form of monostrands comprising continuous, unidirectional multifilamentary fibers embedded in a polymerizable resin.

[0005] The present invention relates more particularly, but not exclusively, to the manufacture of glass resin composite monostrands, with the acronym "CVR", exhibiting high mechanical properties.

[0006] Such long, thin composite materials can be used as composite reinforcements, particularly for reinforcing semi-finished or finished rubber products such as tires for vehicles, for example pneumatic or non-pneumatic, or in applications for reinforcing concrete, snowmobile tracks, tubular structures, etc.

[0007] We are familiar with document EP 1 174 250 - A l which describes a continuous manufacturing process for single-strand CVR comprising the following steps:

[0008] - to create a straight arrangement of glass fibers and drive this arrangement in a direction of advancement;

[0009] - degas the fiber arrangement by the action of a vacuum in a vacuum chamber;

[0010] - upon exiting the vacuum chamber, after degassing, pass through an impregnation chamber filled with resin so as to impregnate said fiber arrangement with liquid resin to obtain an impregnated material containing the fibers and the resin; - pass said impregnated material through a calibration die having a predefined surface area and shape, to impose upon it a single-strand shape; and

[0011] - downstream of the calibration line, in an irradiation chamber, stabilize, solidify the monostrand by photopolymerization of the resin in a UV and / or IR radiation device.

[0012] We also know of document EP 0 074 361 - Al, which describes a process for manufacturing composite parts in which fibers pass through an impregnation device comprising a reservoir containing a composition based on a thermosetting resin and emerge as a prepreg, which is then introduced into a pre-polymerization device to obtain a pre-composite. A shear is used to remove sections of the pre-composite, which are then shaped in a mold at a pressure and temperature adapted to complete the polymerization of the pre-composite.

[0013] Experience shows, however, that the CVR monostrands described can still be improved, particularly in terms of fiber impregnation.

[0014] Indeed, fiber impregnation remains a difficult task to achieve and can lead to a non-homogeneous distribution of fibers, with for example porosities, even despite the presence of a vacuum chamber.

[0015] Currently, the fiber and the impregnation chamber are at atmospheric pressure.

[0016] To control the impregnation of the fibers, it is known to modify the length of the impregnation chamber, the impregnation temperature, and the impregnation time.

[0017] However, such a solution is not satisfactory and can lead to significant congestion of the impregnation chambers as well as a very long impregnation time.

[0018] Thus, there is a need to address the aforementioned drawbacks.

[0019] The invention aims to improve the control of fiber impregnation in order to guarantee good performance of the final composite monostrand. Furthermore, the present invention aims to be easily adapted to existing composite manufacturing facilities.

[0020] The present invention relates to an installation for the continuous manufacturing of a long, thin composite element comprising a bundle of multifilament fibers impregnated with a composition based on a polymerizable material, the installation extending along a longitudinal axis and comprising, in the direction of advancement of the bundle of multifilament fibers:

[0021] - a power supply device configured to form a bundle of multifilament fibers;

[0022] - a degassing chamber for the multifilament fiber bundle;

[0023] - an impregnation chamber filled with a composition based on a polymerizable material and configured to impregnate said degassed multifilament fiber bundle with said composition and form impregnated multifilament fibers, said impregnation chamber being located downstream of the degassing chamber in the direction of advancement of the multifilament fiber bundle;

[0024] - a calibration die, for example an outlet nozzle, positioned at the outlet of the impregnation chamber configured to form a first monostrand impregnated with polymerizable material

[0025] - a first radiation device through which the first monostrand impregnated with polymerizable material circulates and configured to carry out a partial or intermediate polymerization of the first impregnated monostrand and to form a pre-polymerized composite monostrand;

[0026] - at least one second radiating device, separate and distinct from the first radiating device, configured to form a final composite element, and

[0027] - a translational drive device configured to drive the multifilament fiber bundle in translation and to apply a tension on said multifilament fiber bundle.

[0028] The impregnation chamber includes at least one pressure variation device configured to create a pressure variation along the longitudinal axis of the installation inside the impregnation chamber.

[0029] This pressure variation in the impregnation chamber makes it possible to create a transverse flow of the polymerizable material, for example thermosetting resin, radially towards the longitudinal axis and thus pass through the fibers.

[0030] This helps to enhance the effectiveness of the subsequent impregnation and, above all, to guarantee the absence of bubbles or porosity inside the final composite element.

[0031] The first radiation device is configured to pre-polymerize, that is, to perform a partial polymerization of the first impregnated monostrand.

[0032] The second radiation device is configured to perform a final polymerization of the pre-polymerized single strand.

[0033] By "partial polymerization or pre-polymerization" we mean that the degree of polymerization of the radiation-impregnated multifilament fiber bundle has reached between 35% and 65% of complete polymerization.

[0034] As a non-limiting example, the degree of polymerization can be assessed using a "DSC" type measuring instrument, an acronym for "Differential Scanning Calorimetry" in Anglo-Saxon terms.

[0035] The pre-polymerization step makes it possible to obtain a pre-polymerized monostrand, non-sticky, capable of no longer deforming in the free state while being malleable to be deformed under mechanical stress.

[0036] 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 total polymerization.

[0037] Alternatively, a third ultraviolet light source could be added, positioned between the first radiating device and the final radiating device.

[0038] By "long-length composite element" we mean a 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 multifilament fiber feed reels to form a bundle which is driven in translation to successively achieve the impregnation of its fibers with polymerizable material and the polymerization of the material as the bundle moves.

[0039] By "multifilament fiber" we mean a fiber which comprises several elementary filaments arranged side by side to form a bundle whose elementary fibers are unidirectional by being substantially parallel to each other.

[0040] Multifilament fibers can be chosen from the group consisting of glass, carbon, silica, ceramic, flax, hemp, basalt, cellulose fibers, etc. These multifilament fibers are used to make elongated composites produced by impregnating the multifilament fibers with a polymerizable composition.

[0041] 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%, preferably more than 95%, of organic matter.

[0042] Thus, this material can be a thermopolymerizable polymer, for example, based on unsaturated polyester, polyepoxide, phenolic derivatives, or aminoplasts. Preferably, the polymerizable material is cross-linked.

[0043] For example, the polymerizable material is a resin that can be crosslinked by ionizing radiation, the final polymerization being able to be easily triggered and controlled by means of an ionizing treatment, for example of the UV type.

[0044] 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. For example, the final composite element is a cylindrical monostrand, with an outside diameter, for example, between 0.2mm and 3.5mm, comprising multifilament fibers embedded in a polymerizable material, such as a thermosetting resin.

[0045] The elementary filaments, for example, each have an average diameter between 5 pm and 30 pm.

[0046] The drive device is, for example, of the type comprising a motorized traction drum allowing the composite element to be wound around its axis.

[0047] Advantageously, the pressure variation device comprises a first part, a second part and an intermediate part connecting the first part and the second part, the intermediate part having a smaller diameter than the diameter of the first part and than the diameter of the second part.

[0048] The difference in diameter between the intermediate part and the two end parts, i.e. the first and second parts of the pressure variation device, creates a pressure loss inside the impregnation chamber, which in turn causes the pressure inside said impregnation chamber to vary.

[0049] Thus, the pressure of the polymerizable material is increased by the pressure difference along the longitudinal axis inside the impregnation chamber, which allows the air bubbles in the fiber to be replaced by polymerizable material.

[0050] A polymerizable material is, for example, a thermosetting resin.

[0051] Preferably, the diameter of the first part of the pressure variation device is greater than or equal to 150% of the diameter of the intermediate part.

[0052] Preferably, the diameter of the second part of the pressure variation device is greater than or equal to 150% of the diameter of the intermediate part.

[0053] In other words, the intermediate section forms a constriction in the direction of resin flow. For example, the diameter of the first part of the pressure-varying device is between 14 mm and 50 mm, preferably greater than or equal to 30 mm.

[0054] For example, the diameter of the intermediate part of the pressure variation device is between 1mm and 10mm, preferably between 1mm and 4mm.

[0055] For example, the diameter of the second part of the pressure variation device is between 14mm and 50mm, preferably greater than or equal to 30mm.

[0056] For example, at least the intermediate part of the pressure variation device extends over an axial length of between 1mm and 100mm.

[0057] According to one embodiment, the first and second parts are connected to the intermediate part by inclined parts.

[0058] Alternatively, one could foresee a sudden change in diameter between the intermediate part and, respectively, the first part and the second part.

[0059] For example, the first inclined part connecting the first part to the intermediate part forms a first angle with the longitudinal axis between 10° and 50°, preferably between 10° and 20°.

[0060] For example, the second inclined part connecting the intermediate part to the second part forms a second angle with the longitudinal axis between 10° and 80°, preferably between 40° and 80°.

[0061] Preferably, the thermosetting resin is configured to enter the impregnation chamber and in particular the pressure variation device at an inlet velocity between 0.01m / s and 2m / s.

[0062] According to one embodiment, the impregnation chamber includes a plurality of pressure variation devices in series along the longitudinal axis in order to further improve resin impregnation and fiber distribution.

[0063] For example, the direction of flow of the thermosetting resin in the impregnation chamber and in particular in the pressure variation device can be in the same direction as the direction of fiber circulation or in the opposite direction to the direction of fiber circulation.

[0064] The values ​​of the first angle and the second angle are determined according to the direction of resin flow. The smaller angle between the first angle and the second angle is preferably the angle of the inclined part located downstream of the intermediate part, i.e. the constriction, in the direction of resin flow.

[0065] Preferably, the impregnation chamber is supplied with polymerizable material from an external reservoir, preferably using a pump.

[0066] The impregnation chamber includes an inlet and an outlet.

[0067] The polymerizable resin circulates in the impregnation chamber at a speed generated by the pump.

[0068] According to one embodiment, the installation includes 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 60°C to 80°C.

[0069] Alternatively, it could be envisaged that the installation would not include such a heating device.

[0070] According to one embodiment, the first radiation device includes a first light source comprising ultraviolet radiation, acronym UV.

[0071] The exposure time of the impregnated monofilament to the first ultraviolet light source is between 0.1 s and 1.5 s, preferably between 0.4 s and 0.7 s

[0072] The power of the first combined UV radiation light source is between 2kW and 14kW, preferably between 4kW and 7kW.

[0073] According to another 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.

[0074] According to another embodiment, the first light source comprises a plurality of mercury vapor lamps configured to emit broad-spectrum ultraviolet radiation, infrared radiation, and visible light.

[0075] According to one embodiment, the second radiation device includes a second light source with combined ultraviolet and infrared radiation or with infrared radiation alone to complete the polymerization of the pre-polymerized monostrand.

[0076] The exposure time of the pre-polymerized monostrand 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.

[0077] The power of the second UV and infrared light source is between 100kW and 60kW, preferably between 20kW and 40kW

[0078] According to one variant, the second light source comprises a plurality of light-emitting diodes, acronym LEDs, preferably directed radially towards the pre-polymerized single strand, with available wavelengths between 200nm and 405nm, preferably between 365nm and 405nm. In this case, the LEDs are combined with infrared radiation.

[0079] According to another variant, the second light source could comprise a plurality of mercury vapor lamps, the exposure time of the pre-polymerized monostrand being between 1 s and 4 s, preferably between 1.5 s and 2 s, at a power between 1 OkW and 60kW, preferably between 20kW and 40kW.

[0080] According to one variant, the second light source could comprise a plurality of mercury vapor lamps configured to emit broad-spectrum ultraviolet (UV) radiation, infrared radiation, and visible light. The mercury vapor lamps can be combined with infrared radiation with wavelengths between 1 pm and 3 pm.

[0081] According to yet another variant, the second radiation device could be expected to include a light source with infrared radiation only, configured to emit only infrared radiation, with a wavelength between 1 pm and 3 pm.

[0082] In this case, the exposure time of the pre-polymerized monostrand 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 1 OkW and 60kW, preferably between 20kW and 40kW.

[0083] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0084] [Fig. 1] schematically represents an installation for manufacturing a composite element according to an embodiment of the invention; and

[0085] [Fig.2] shows a cross-section of the impregnation chamber of the installation in Figure 1.

[0086] Figure 1 schematically illustrates a manufacturing installation 1 for a long, elongated EF composite element.

[0087] By "long-line composite element" we mean a 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 multifilament fiber feed reels Fi_0 to form a bundle which is driven in translation along the arrow F to successively achieve the impregnation of its fibers with polymerizable material and the polymerization of the material as the bundle moves.

[0088] A "multifilament fiber" is defined as a fiber composed of several elementary filaments arranged side-by-side to form a bundle. The elementary fibers are unidirectional and substantially parallel to each other. Multifilament fibers can be selected from a group including glass, carbon, silica, ceramic, flax, hemp, basalt, cellulose, and other fibers. These multifilament fibers are used to create elongated composites by impregnating them with a polymerizable composition.

[0089] 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% organic matter, or even more than 95% organic matter.

[0090] Thus, this material can be a thermopolymerizable polymer, for example, based on unsaturated polyester, polyepoxide, phenolic derivatives, or aminoplasts. Preferably, the polymerizable material is cross-linked.

[0091] For example, the polymerizable material is a resin that can be crosslinked by ionizing radiation, the final polymerization being able to be easily triggered and controlled by means of an ionizing treatment, for example of the UV type.

[0092] 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.

[0093] In the example illustrated in the figures, the final composite element EF is a cylindrical monostrand of large diameter, for example between 10mm and 30mm or a cylindrical monostrand of small diameter, for example between 0.2mm and 3.5mm.

[0094] The elementary filaments, for example, each have an average diameter between 5 pm and 30 pm.

[0095] The installation of the invention allows, of course, the manufacture of single strands with circular, rectangular, oval, elliptical, etc., cross-sections. As illustrated in Figure 1, the manufacturing installation 1 comprises, in the direction of advancement of the multifilament fiber bundle along arrow F:

[0096] - a power supply device 10 comprising here one or more reels supplying elementary filaments Fi_0 to form a bundle of multifilament fibers E0,

[0097] - a vacuum chamber 13 or degassing chamber arranged between an inlet nozzle 13a and a separation nozzle 13b;

[0098] - an impregnation chamber 14 downstream of the vacuum chamber 13 and in particular of the separation nozzle 13b and filled with an impregnation composition 15 based on a polymerizable material

[0099] - a calibration die 16, here an outlet nozzle, arranged at the outlet of the impregnation chamber 14 so as to form a first monostrand E l impregnated with polymerizable material;

[0100] - a first radiation device 18 through which the first monostrand E l impregnated with polymerizable material circulates and configured to carry out a partial or intermediate polymerization of the first impregnated monostrand E l and to form a pre-polymerized composite monostrand E2;

[0101] - a second radiation device 19 or final radiation device, separate from the first radiation device 18, through which the pre-polymerized composite monostrand E2 circulates and is configured to carry out a final polymerization to form the final composite element EF; and

[0102] - a translational drive device D along arrow F configured to drive the multifilament fiber bundle in translation to successively perform degassing, impregnation of its fibers with polymerizable material and polymerization of the material as the bundle moves.

[0103] The vacuum chamber 13, the impregnation chamber 14, the nozzle 16, the first radiation device 18, and the second radiation device 19 are arranged along the same axis, corresponding to the longitudinal axis X-X' of the installation 1 in the longitudinal direction X. Generally, the fibers are supplied by one or more reels, called "rovings" in Anglo-Saxon terminology. The beam, originating from the feed device 10, passes through the installation 1, advancing in the direction of arrow F, set in motion by the drive device D located at the installation's output.

[0104] The drive device D is, for example, of the type comprising a motorized traction drum allowing the composite element to be wound around its axis.

[0105] Alternatively, any drive device could be used to set the multifilament fiber bundle in motion along a direction of advancement.

[0106] The vacuum chamber 13 is, in a manner known per se, delimited by a rigid inlet nozzle 13a, having a through orifice and a rigid separation nozzle 13b, also having a through orifice located axially opposite the orifice of the inlet nozzle 13a.

[0107] The multifilament fiber bundle E0 is introduced into the vacuum chamber 13 by passing it through the orifice of the inlet nozzle 13a and exits through the orifice of the separation nozzle 13b.

[0108] The vacuum chamber 13 is connected to a vacuum pump (not shown) which maintains a pressure level of approximately 0.1 bar in the vacuum chamber 13, despite the passage of multifilament fiber bundles E0 through the orifice having a diameter greater than those of the multifilament fiber bundle E0 which passes through them.

[0109] The vacuum chamber 13 allows the multifilament fiber bundle E0 to be degassed by the action of vacuum.

[0110] Alternatively, it could be envisaged that installation 1 would be devoid of such a vacuum chamber.

[0111] After passing through the vacuum chamber 13, the multifilament fiber bundle E0 enters an impregnation chamber 14 which is totally full of polymerizable impregnation material, therefore devoid of air.

[0112] The impregnation chamber 14 is an airtight enclosure, delimited by the separation nozzle 13b and a rigid calibration nozzle, also equipped with a through orifice located axially opposite the orifice of the separation nozzle 13b.

[0113] The impregnation chamber 14 is supplied with polymerizable material 15 from an external reservoir (not shown) preferably using a pump (not shown).

[0114] The impregnation chamber 14 includes an inlet 14a and an outlet 14b.

[0115] The polymerizable material 15 flows through the impregnation chamber 14 at a speed generated by the pump.

[0116] The polymerizable material 15 is preferably thermosetting resin.

[0117] The impregnation chamber 14 is completely filled with polymerizable material so that the multifilament fiber bundle exiting the vacuum chamber 13 and passing through it along a linear path is completely impregnated with polymerizable material.

[0118] The impregnation chamber 14 is, here, associated with a heating device 15b configured to heat the polymerizable material to a temperature between 50°C and 95°C, preferably between 60°C and 80°C.

[0119] Thus, the impregnated multifilament fiber bundle exits the impregnation chamber 14 at a temperature between 50°C and 95°C, preferably between 60°C and 80°C, before passing through the radiation devices 18, 19.

[0120] Alternatively, we could not provide for such a heating device 1b.

[0121] The calibration die 16 here includes a calibration nozzle configured to shape the bundle of multifilament fibers exiting the impregnation chamber 14 to form a single strand of impregnated multifilament fibers E l.

[0122] Alternatively, any other device could be provided allowing the shaping of the impregnated monostrand E1 before polymerization in the radiation devices 18, 19. As illustrated in detail in Figure 2, the impregnation chamber 14 includes a pressure variation device 17 having a particular shape configured to create a pressure variation along the longitudinal axis X-X' of the installation 1 inside the impregnation chamber 14.

[0123] This pressure variation in the impregnation chamber 14 creates a transverse flow of the thermosetting resin radially towards the longitudinal axis, thus allowing it to pass through the EO fibers. This enhances the efficiency of subsequent impregnation and, most importantly, ensures the absence of bubbles or porosity within the final composite element EF.

[0124] In the example illustrated in detail in Figure 2, the pressure variation device 17 comprises a first part 17a, a second part 17c and an intermediate part 17b linking the first part 17a and the second part 17b.

[0125] The first part 17a has a diameter 0A greater than the diameter 0B of the intermediate part 17b, for example greater than or equal to 150% of the diameter 0B of the intermediate part 17b.

[0126] The second part 17c has a diameter 0C greater than the diameter 0B of the intermediate part 17b, for example greater than or equal to 150% of the diameter of the intermediate part 17b.

[0127] The first part 17a and the second part 17c have, here, an identical diameter 0A, 0C.

[0128] Alternatively, we could foresee that the diameter 0C of the second part 17c is smaller than the diameter 0A of the first part 17a.

[0129] For example, the diameter 0A of the first part 17a is between 14mm and 50mm, preferably greater than or equal to 30mm.

[0130] For example, the diameter 0B of the intermediate part 17b is between 1mm and 10mm, preferably between 1mm and 4mm.

[0131] For example, the diameter 0C of the second part 17c is between 14mm and 50mm, preferably greater than or equal to 30mm.

[0132] For example, the axial length L of the intermediate part 17b is between 1 mm and 100 mm. The first and second parts 17a, 17c are connected to the intermediate part 17c by inclined parts 17d, 17e.

[0133] Alternatively, we could foresee a sudden change in diameter, i.e. a radial break, respectively between the first part 17a and the intermediate part 17b and between the intermediate part 17c and the second part 17c.

[0134] The first inclined part 17d connecting the first part 17a to the intermediate part 17b forms a first angle a with the longitudinal axis X between 10° and 50°, preferably between 10° and 20°.

[0135] The second inclined part 17e connecting the intermediate part 17b to the second part 17c forms a second angle P with the longitudinal axis X between 10° and 80°, preferably between 40° and 80°.

[0136] The entry velocity of the thermosetting resin into the impregnation chamber 14 and in particular into the pressure variation device 17 is between 0.01m / s and 2m / s.

[0137] The difference in diameter between the intermediate part 17b and the two end parts, i.e. the first and second parts 17a, 17c of the pressure variation device 17 allows a pressure loss to be created inside the impregnation chamber 14, which has the effect of varying the pressure inside said impregnation chamber 14.

[0138] Thus, the pressure of the thermosetting resin is increased by the pressure difference along the longitudinal axis X-X' inside the impregnation chamber 14, which allows the replacement of air bubbles in the fiber by resin.

[0139] It could also be envisaged to arrange a plurality of pressure variation devices 17 in series along the longitudinal axis X-X' in order to further improve the impregnation of the resin and the distribution of the fibers.

[0140] The flow direction of the thermosetting resin in the impregnation chamber 14 and in particular in the pressure variation device 17 can be in the same direction as the direction of circulation of the fibers E0 or in the opposite direction to the direction of circulation of the fibers E0. The first radiation device 18 is configured to pre-polymerize, that is to say to perform a partial polymerization of the impregnated monostrand E1.

[0141] The first radiation device 18 includes a first light source 18a with ultraviolet radiation, acronym UV.

[0142] The exposure time of the impregnated monostrand E l to the first ultraviolet light source is between 0.1 s and 1.5s, preferably between 0.4s and 0.7s.

[0143] The power of the first ultraviolet light source is between 2 kW and 14 kW, preferably between 4 kW and 7 kW.

[0144] 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.

[0145] For example, the power of LEDs is between 2kW and 14kW, preferably between 4kW and 7kW.

[0146] According to yet another variant, the first light source is configured to emit only monochromatic ultraviolet radiation, for example via LEDs, with available wavelengths of 365, 385, 395, 405nm, and more generally between 200nm and 405nm.

[0147] The first 18a ultraviolet LED light source therefore allows the emission of radial radiation on the impregnated single strand E l, with or without reflectors to optimize irradiation.

[0148] The use of LEDs can reduce styrene vapors, minimize fouling of any protective tube, and reduce variations in light intensity, resulting in more consistent polymerization of multifilament fibers.

[0149] Furthermore, LEDs have a longer lifespan and lower or similar energy consumption to mercury vapor lamps and release less styrene vapor into the atmosphere.

[0150] According to yet another variant, the first light source 18a could comprise a plurality of mercury vapor lamps configured to emit broad-spectrum ultraviolet radiation, infrared radiation, and visible light.

[0151] According to another embodiment, the first ultraviolet light source 18a comprises a plurality of mercury vapor lamps configured to emit broad-spectrum ultraviolet radiation, infrared radiation, and visible light.

[0152] For example, the exposure time of the impregnated single strand E l to the first UV light source comprising a plurality of mercury vapor lamps is between 0.1 s and 4.5 s, preferably between 0.4 s and 2.3 s, at a power between 1kW and 50kW, preferably between 5kW and 24kW.

[0153] The first radiation device 18 is configured to partially polymerize or pre-polymerize the impregnated single strand E1 and deliver a pre-polymerized impregnated single strand E2.

[0154] The UV rays from the first UV radiation source are absorbed by the photoinitiators contained in the polymerizable material, thus initiating the polymerization of the resin. It is important that the wavelength or spectrum of the first UV light source be matched to the photoinitiator.

[0155] By "partial polymerization or pre-polymerization", we mean that the degree of polymerization of the impregnated single strand E reaches between 35% and 65% of complete polymerization.

[0156] Without limitation, the degree of polymerization can be assessed using a "DSC" type measuring instrument, an acronym for "Differential Scanning Calorimetry" in Anglo-Saxon terms.

[0157] In general, the exposure time of the impregnated monostrand E l to the first UV 18a light source is between 0.1 s and 4.5s.

[0158] In general, the power of the first UV 18a light source is between 1kW and 50kW.

[0159] For example, when the first light source includes LEDs, the power of the LEDs is between 1 kW and 16 kW, preferably between 3 kW and 8 kW. For example, the exposure time of the impregnated single strand E 1 to the first UV light source including LEDs is between 0.1 s and 1.5 s, preferably between 0.3 s and 0.7 s.

[0160] The pre-polymerization step makes it possible to obtain a pre-polymerized E2 impregnated monostrand, non-sticky, capable of no longer deforming in the free state while being malleable to be deformed under mechanical stress.

[0161] The second radiation device 19 or final radiation device includes a second light source 19a with combined ultraviolet and infrared radiation or with infrared radiation alone configured to complete the polymerization of the pre-polymerized impregnated monostrand E2.

[0162] Complete polymerization of the composite is achieved when the degree of polymerization of the polymerizable material is close to 100%, preferably greater than or equal to 95%.

[0163] The exposure time of the pre-polymerized impregnated monostrand E2 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.

[0164] The power of the second combined UV and infrared light source is between 10 kW and 60 kW, preferably between 20 kW and 40 kW.

[0165] According to one variant, the second light source 19a comprises a plurality of light-emitting diodes (not shown), acronym LED, preferably directed radially towards the pre-polymerized impregnated single strand E2 and 405nm, preferably between 365nm and 405nm.

[0166] According to another variant, the second light source 19a could comprise a plurality of mercury vapor lamps, the exposure time of the pre-polymerized impregnated monostrand E2 being between 1 s and 4 s, preferably between 1.5 s and 2 s, at a power between 10 kW and 60 kW, preferably between 20 kW and 40 kW.

[0167] According to one variant, the second light source 19a could comprise a plurality of mercury vapor lamps configured to emit broad-spectrum ultraviolet UV radiation, infrared radiation and visible light and a plurality of lamps with infrared radiation wavelengths between 1 pm and 3 pm.

[0168] According to yet another variant, the second light source could be solely infrared. In this case, the second radiating device comprises a light source emitting only infrared radiation, configured to emit only infrared radiation with a wavelength between 1 pm and 3 pm.

[0169] In this case, the exposure time of the pre-polymerized impregnated monostrand E2 to the second light source 19a 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 1 OkW and 60kW, preferably between 20kW and 40kW.

[0170] Alternatively, a third radiation device with an infrared light source could be provided downstream of the second radiation device.

[0171] The installation and manufacturing process according to the invention makes it possible to obtain long, slender composite elements based on multifilamentary fibers whose shape and dimensions are well controlled and whose mechanical properties are homogeneous, and this over their entire length.

[0172] Furthermore, the installation and manufacturing process according to the invention makes it possible to obtain composite elements having cross-sections of different sizes and this at a high production rate.

[0173] For example, for a CVR composite, with the process according to the invention, sections with a diameter between 0.2 and 3.5mm can be obtained at a rate of approximately 150m / min.

Claims

DEMANDS 1. Installation (1) for the continuous manufacture of a long, thin composite element (FE) comprising a bundle of multifilament fibers impregnated with a composition based on a polymerizable material, the installation (1) extending along a longitudinal axis (X-X') and comprising, in the direction of advancement (X) of the bundle of multifilament fibers: - a power supply device (10) configured to form a multifilament fiber bundle (E0); - a degassing chamber (13) for the multifilament fiber bundle (E0); - an impregnation chamber (14) filled with a composition based on a polymerizable material and configured to impregnate said degassed multifilament fiber bundle (E0) with said composition and form impregnated multifilament fibers (E1), said impregnation chamber (14) being located downstream of the degassing chamber in the direction of advancement of the multifilament fiber bundle; - a calibration die (16) disposed at the outlet of the impregnation chamber (14) configured to form a first monostrand (E l ) impregnated with polymerizable material - a first radiation device ( 18) through which the first monostrand (E l ) impregnated with polymerizable material circulates and configured to carry out a partial polymerization of the first impregnated monostrand (E l ) and to form a pre-polymerized composite monostrand (E2); - at least one second radiating device (19), separate and distinct from the first radiating device (18) configured to form a final composite element (FE), and - a translational drive device (D) configured to drive the multifilament fiber bundle in translation and to apply a tension to said multifilament fiber bundle, characterized in that the impregnation chamber (14) comprises at least one pressure variation device (17) configured to create a pressure variation along the longitudinal axis (X-X') of the installation (1) inside the impregnation chamber (14).

2. Installation (1) according to claim 1, wherein the pressure variation device (17) comprises a first part (17a), a second part (17c) and an intermediate part (17b) connecting the first part (17a) and the second part (17b), the intermediate part (17b) comprising a diameter (0B) smaller than the diameter (0A) of the first part (17a) and than the diameter (0C) of the second part (17c).

3. Installation (1) according to claim 2, wherein the diameter (0A) of the first part (17a) of the pressure variation device (17) is greater than or equal to 150% of the diameter (0B) of the intermediate part (17b).

4. Installation (1) according to claim 2 or 3, wherein the diameter (0B) of the second part (17b) of the pressure variation device (17) is greater than or equal to 150% of the diameter (0B) of the intermediate part (17b).

5. Installation (1) according to any one of claims 2 to 4, wherein the diameter (0A) of the first part (17a) of the pressure variation device (17) is between 14mm and 50mm, preferably greater than or equal to 30mm.

6. Installation (1) according to any one of claims 2 to 5, wherein the diameter (0B) of the intermediate part (17b) of the pressure variation device (17) is between 1mm and 10mm, preferably between 1mm and 4mm.

7. Installation (1) according to any one of claims 2 to 6, wherein the diameter (0C) of the second part (17c) of the pressure variation device (17) is between 14mm and 50mm, preferably greater than or equal to 30mm.

8. Installation (1) according to any one of claims 2 to 7, wherein at least the intermediate part (17b) of the pressure variation device (17) has an axial length (L) between 1mm and 100mm.

9. Installation (1) according to any one of claims 2 to 8, wherein the first and second parts (17a, 17c) are connected to the intermediate part (17c) by inclined parts (17d, 17e).

10. Installation (1) according to claim 9, wherein a first inclined part (17d) connects the first part (17a) to the intermediate part (17b) and forms a first angle (a) with the longitudinal axis (X-X') between 10° and 50°, preferably between 10° and 20°. 1 1. Installation (1 ) according to claim 9 or 10, wherein a second inclined part (17e) connects the intermediate part (17b) to the second part (17c) and forms a second angle (P) with the longitudinal axis (X-X') between 10° and 80°, preferably between 40° and 80°.

12. Installation (1) according to any of the preceding claims, wherein the polymerizable material is configured to enter the impregnation chamber (14) and in particular the pressure variation device (17) at an inlet velocity between 0.01 m / s and 2 m / s.

13. Installation (1) according to any of the preceding claims, wherein the impregnation chamber (14) comprises a plurality of pressure variation devices (17) in series along the longitudinal axis (X-X').

14. Installation (1) according to any one of the preceding claims, wherein the first radiating device (18) comprises a first light source (18a) of ultraviolet radiation.

15. Installation (1) according to claim 14, wherein the first light source (18a) comprises a plurality of light-emitting diodes configured to emit monochromatic ultraviolet radiation with a wavelength between 200nm and 405nm.

16. Installation (1) according to claims 14 and 15, wherein the first ultraviolet light source (18a) further comprises infrared radiation.

17. Installation (1) according to claim 14, wherein the first ultraviolet light source (18a) comprises a plurality of mercury vapor lamps configured to emit broad-spectrum ultraviolet radiation, infrared radiation and visible light.

18. Installation (1) according to any one of the preceding claims, wherein the second radiation device (19) comprises a second light source (19a) with combined ultraviolet and infrared radiation or with infrared radiation alone to complete the polymerization of the pre-polymerized single strand (E2).

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