METHOD FOR PRODUCING FOLDED THERMOPLASTIC COMPOSITES, FOLDED THERMOPLASTIC COMPOSITES AND SYSTEM FOR MANUFACTURING FOLDED THERMOPLASTIC COMPOSITES - Patent application

Abstract

The present invention relates to a method (100) for producing a folded thermoplastic composite comprising up to 35% by volume of a polymer matrix comprising a (meth)acrylic polymer, and at least 65% by volume of fibers, the method comprising the steps of: - providing a thermoplastic composite (110); - heating (120) a portion of the thermoplastic composite, said heating being selected from conductive heating, radiative heating and / or volumetric heating, and the heating time and / or heating temperature being selected depending on at least a thickness of the thermoplastic composite; - creating folded sections in the heated portion by folding the heated portion (130); - cooling (140) the folded sections at a cooling temperature and / or cooling time selected according to the glass transition temperature (Tg) of the folded thermoplastic composite to solidify and form a folded thermoplastic composite. Includes.

Description

[Technical field]

[0001]

[0001] The present invention relates to the field of thermoplastic composites, more particularly to the field of reinforcing elements.

[0002] The present invention relates to a method for manufacturing a folded thermoplastic composite, a folded thermoplastic composite, and a system for manufacturing a folded thermoplastic composite.

[0003] [Description of Related Art]

[0003] Reinforcing elements are commonly used to reinforce structures in several sectors, such as automotive, transportation, aviation, aerospace, solar power, construction and building, and / or wind energy applications.

[0004]

[0004] Currently, reinforcing elements in the form of composite reinforcing elements are known.

[0005]

[0005] Composite reinforcing elements are usually composed of a matrix (generally a polymer matrix comprising a thermosetting polymer) and fibers. Such composite reinforcing elements are often produced by a pultrusion process and have a linear profile.

[0006]

[0006] In the conventional pultrusion process, the fibers are impregnated by wetting them and passing them through a resin bath, and the impregnated fiber bundle is cooled. It then assumes a linear configuration. The resulting composite reinforcing element is usually produced directly in its final (linear) form.

[0007]

[0007] Linear shapes cannot meet all the requirements of the industry. Thermosetting polymers cannot be universally applied because of the high transportation and storage volume, and are more expensive. Moreover, the evolution of the application field requires new geometric shapes, especially for bent reinforcement elements.

[0008]

[0008] It is known to manufacture reinforcing elements from resins that include thermoplastic polymers. Advantageously, reinforcing elements that include thermoplastic polymers can be heated and cooled continuously.

[0009]

[0009] However, there is a drawback in that continuous heating reduces the thermal stability and some of the properties of the reinforcing element, such as bending resistance, bending strength, retention, peeling, etc.

[0010]

[0010] Furthermore, as explained above, thermosetting resins cannot change shape after cooling, so their curvature cannot be adjusted to fit the structure they are reinforcing, nor can they be modified after cooling, for example for transportation or storage.

[0011]

[0011] Furthermore, current thermoset or thermoplastic composites involve compression of the fibers at the point of curvature, which renders the fibers unable to withstand tension and greatly reduces structural reinforcement.

[0012] Furthermore, today thermosets must be manually molded in a pultrusion process, adding additional cost and time.

[0013]

[0013] Currently, for thermoplastic polymers, heating is usually done in a conventional oven and the thermoplastic polymer may be molded multiple times, which makes it easier to mold on-site and also reduces transportation and storage problems.

[0014]

[0014] However, the heating temperature and heating time in the current pultrusion process of thermoplastic polymers can cause surface degradation, resin degradation, and the heating is not uniform, resulting in a large thermal phase shift that reduces the thermal properties between the center of the reinforcing element and its walls (e.g., outermost regions). Furthermore, the heating is very slow (5 minutes or more), resulting in slow manufacturing and production.

[0015]

[0015] Therefore, a solution is needed for producing bent thermoplastic composites that have improved mechanical and chemical qualities, particularly without surface degradation, reduced thermal phase shift, and easier storage, transportation time, and costs. Summary of the Invention

[0016]

[0016] The following presents a simplified summary of selected aspects, embodiments, and examples of the invention in order to provide a basic understanding of the invention. However, this summary does not constitute an extensive overview of all aspects, embodiments, and examples of the invention. The sole purpose of the summary is to present selected aspects, embodiments, and examples of the invention in a concise form as a prelude to the more detailed description of the aspects, embodiments, and examples of the invention that follows the summary.

[0017]

[0017] The present invention aims to overcome the drawbacks of the prior art. In particular, the present invention relates to a method for producing a folded thermoplastic composite from a thermoplastic composite, the thermoplastic composite comprising a polymer matrix containing up to 35% by volume of a (meth)acrylic polymer and at least 65% by volume of fibers, the method comprising: - providing a thermoplastic composite, preferably by pultrusion; - heating a portion of the thermoplastic composite, said heating being selected from conductive heating, radiative heating and / or volumetric heating, and a heating time and / or heating temperature being selected depending on at least a thickness of the thermoplastic composite; - creating folded sections in the heated portion by folding the heated portion; - cooling and solidifying the folded section at a cooling temperature and / or cooling time selected according to the glass transition temperature (Tg) of the folded thermoplastic composite to form a folded thermoplastic composite; Includes.

[0018]

[0018] Such a method makes it possible to produce folded thermoplastic composites with improved mechanical and chemical properties, in particular without surface degradation and reduced thermal phase shift (delta), while at the same time guaranteeing time savings and cost reductions.

[0019]

[0019] In fact, thanks to this method, the heating can be adjusted to the thermoplastic composite since it is rapid and depends on the thickness of the thermoplastic composite, thus reducing the difference between the inner and surface temperatures of the thermoplastic composite, which reduces the phase shift that affects the resistance even at the bending points.

[0020]

[0020] Furthermore, the composition of the thermoplastic composite having a polymer matrix containing 35% by volume or less of a (meth)acrylic polymer and at least 65% by volume of fibers allows the heating temperature and heating time to be reduced. Furthermore, the at least 65% by volume of fibers improves the mechanical and chemical properties of the folded section.

[0021]

[0021] This method makes it possible to adapt the bending, resistance and heating properties to the thermoplastic composite as a reinforcing element.

[0022]

[0022] Furthermore, this method allows for rapid on-site shaping, facilitating storage and transport of the folded reinforcement elements, and also allows for the curvature to be adjusted to suit the structure to be reinforced, or to be altered after cooling.

[0023]

[0023] According to other optional features of the method, optionally, one or more of the following features may be included, either alone or in combination. the heating step is radiant heating, preferably infrared (IR) heating; the heating time is less than or equal to 95 seconds, preferably less than or equal to 60 seconds, and preferably the inner temperature of the thermoplastic composite is less than or equal to 180°C; - between the heating and cooling steps, the temperature difference between the inner and outer temperatures of the thermoplastic composite is preferably between 0°C and 50°C after 30 seconds of heating, the temperature difference between the inner and outer temperatures of the thermoplastic composite during the heating step is preferably less than or equal to 80° C. within 95 seconds of heating; the thermoplastic composite is obtained by pultrusion, preferably by reactive pultrusion; The thermoplastic composites may be crosslinked, partially crosslinked or non-crosslinked.

[0024]

[0024] According to another aspect of the present invention, there is provided a folded thermoplastic composite obtained from a thermoplastic composite, the thermoplastic composite comprising a polymer matrix comprising 35% or less by volume of a (meth)acrylic polymer, and at least 65% by volume of fibers.

[0025]

[0025] Such folded thermoplastic composites exhibit improved mechanical resistance at that level of curvature. They have improved flexibility and the fibers of the folded thermoplastic composites are free of buckling and cracking and exhibit uniform strength. Furthermore, such folded thermoplastic composites do not exhibit degradation of their surfaces. Furthermore, such folded thermoplastic composites can be easily folded on demand, close to the site. Advantageously, the folded thermoplastic composites meet the requirements of ASTM D7957, and more advantageously, the requirements of ASTM D7914, and exhibit bending properties similar to those of commercially available thermosets folded by hand, or more precisely, those folded before the thermosets are cured.

[0026]

[0026] According to another aspect, the present invention relates to the use of the folded thermoplastic composite according to the present invention in automotive, transportation, marine, rail, sports, aviation, aerospace, photovoltaic, construction and building, and / or wind energy applications, preferably for reinforcing structures in automotive, transportation, marine, rail, sports, aviation, aerospace, photovoltaic, construction and building, and / or wind energy applications.

[0027]

[0027] Such uses make it possible to strengthen structures in a variety of applications.

[0028] According to another aspect, the present invention provides a system for producing a folded thermoplastic composite from a thermoplastic composite, the thermoplastic composite comprising a polymer matrix comprising up to 35% by volume of a (meth)acrylic polymer and at least 65% by volume of fibers, the system comprising: a heating device (11) configured to heat a portion of the thermoplastic composite, the heating device being selected from conductive heating, radiative heating and / or volumetric heating, the heating time and / or heating temperature being selected depending on at least the thickness of the thermoplastic composite; and a folding device configured to fold the heated portion to form a folded section in the heated portion; and a cooling device configured to solidify the folded sections to form a folded thermoplastic composite at a cooling temperature and / or cooling time selected according to the glass transition temperature of the thermoplastic composite.

[0029] Such a system allows easy production of folded thermoplastic composites, further reducing time and costs.

[0030] [Brief description of the drawings]

[0030] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0031] [Figure 1] 2 illustrates a flowchart of a method according to an embodiment of the present invention. [Diagram 2] An example of the delta temperature as a function of heating temperature and time for a D16mm thermoplastic composite rod is shown. [Diagram 3]An example of heating temperature and delta temperature as a function of time for a thermoplastic composite flat panel P4mm is shown. [Figure 4] 1 shows a schematic diagram of a system according to one embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032]

[0031] Examples of embodiments of the present invention are described below.

[0033]

[0032] "Polymer" means either a copolymer or a homopolymer. The term "copolymer" means a polymer with several different monomer units grouped together, and the term "homopolymer" means a polymer with identical monomer units grouped together. "Block copolymer" means a polymer containing one or more consecutive blocks of different polymer species each, where the polymer blocks are chemically distinct from each other and are linked by covalent bonds. These polymer blocks are also called polymer blocks.

[0034]

[0033] In the sense of the present invention, the expression "polymer composite" means a multicomponent material comprising at least two immiscible components, of which at least one component is a polymer and the other component may, for example, be a fiber reinforcement material.

[0035]

[0034] By "fibrous reinforcement" or "fibrous substrate" or "fiber" in the sense of the present invention is meant a plurality of fibers, unidirectional fibers or braids, or continuous filament mats, woven fabrics, felts, or nonwoven fabrics, which may be in the form of bands, webs, braids, wicks, or pieces.

[0036]

[0035] The term "matrix" is understood to mean a material capable of acting as a binder and transmitting forces to the fiber reinforcement. "Polymer matrix" includes polymers, but may also include other compounds and materials. Thus, "(meth)acrylic polymer matrix" refers to all kinds of compounds, polymers, oligomers, copolymers or block copolymers, acrylic and methacrylic. However, it does not depart from the scope of the invention if the (meth)acrylic polymer matrix contains up to 10% by weight, preferably less than 5% by weight, of other non-acrylic monomers, for example selected from the group of butadiene, isoprene, styrene, substituted styrenes such as α-methylstyrene or tert-butylstyrene, cyclosiloxanes, vinylnaphthalenes and vinylpyridines.

[0037]

[0036] In the sense of the present invention, the term "initiator" means a compound capable of initiating the polymerization of a monomer or monomers.

[0038]

[0037] The term "polymerization" in the sense of the present invention refers to the process of converting a monomer or a mixture of monomers into a polymer.

[0039]

[0038] In the sense of the present invention, the term "monomer" means a molecule capable of polymerization.

[0040]

[0039] For the purposes of the present invention, the term "thermoplastic polymer" is understood to mean a polymer which is generally solid at room temperature, crystalline, semi-crystalline or amorphous, which softens during the increase in temperature, in particular passes through a glass transition temperature (Tg) and flows at higher temperatures, where a clear melting can be observed when passing through the so-called melting point (Tf) (if semi-crystalline), and which becomes solid again when the temperature drops below the melting point and below the glass transition temperature. This also applies to thermoplastic polymers which are slightly crosslinked due to the presence of polyfunctional monomers or oligomers in the formulation of "syrup" (meth)acrylates, preferably in a mass percentage of less than 10%, preferably less than 5%, therefore preferably less than 2%, and which can be thermoformed when heated above their softening temperature.

[0041]

[0040] The term "thermosetting polymer" is understood in the sense of the present invention to mean a plastic material which is irreversibly transformed by polymerization into an insoluble polymer network.

[0042]

[0041] The term "(meth)acrylic monomers" is understood to mean all kinds of acrylic and methacrylic monomers.

[0043]

[0042] The term "(meth)acrylic polymer" is understood to mean a polymer essentially comprising (meth)acrylic monomers which represent at least 50% by weight of the (meth)acrylic polymer.

[0044]

[0043] In the sense of the present invention, the term "PMMA" means homopolymers and copolymers of methyl methacrylate (MMA), the weight ratio of MMA in PMMA being preferably at least 70% by weight relative to the MMA copolymers.

[0045]

[0044] As used herein, the expression "reinforcement element" refers to an element used to support a structure in order to strengthen, brace, stiffen, reinforce, or improve the mechanical properties (reinforcement, tensile, elastic, etc.), thermal, electrical, and / or chemical properties of the structure.

[0046]

[0045] As used herein, the term "rebar" refers to steel bars used in reinforced concrete and masonry structures as tension devices to strengthen and assist concrete under tension. Rebars significantly increase the tensile strength of concrete and structures.

[0047]

[0046] The abbreviation "phr" stands for parts by weight per 100 parts of composition. For example, 1 phr of initiator in a composition means that 1 kg of initiator is added to 100 kg of the composition.

[0048]

[0047] The abbreviation "ppm" refers to parts by weight per million parts of a composition. For example, 1000 ppm of a compound in a composition means that 0.1 kg of the compound is contained in 100 kg of the composition.

[0049]

[0048] The terms "inner temperature" or "core temperature" are used interchangeably to refer to the core temperature of a thermoplastic composite, while "outer temperature" or "surface temperature" are also used interchangeably to refer to the temperature of the outer surface of a thermoplastic composite. Additionally, temperatures (inner or outer) can be measured and tracked with thermocouples or infrared (IR) sensors.

[0050]

[0049] In this specification, where ranges are specified, the boundaries are included.

[0051] The present invention relates to a method 100 for producing a folded thermoplastic composite from a thermoplastic composite.

[0052]

[0051] The folded thermoplastic composite is made from a thermoplastic composite. Preferably, the thermoplastic composite is obtained from a pultrusion process, more preferably from a reactive pultrusion process. The pultrusion and reactive pultrusion processes are known to those skilled in the art. In these processes, the fibers are guided through a resin bath or infusion chamber containing a composition or syrup. The fibers as fibrous substrates are, for example, in the form of unidirectional rovings or continuous filament mats. After impregnation in the resin bath, the wet fibers are passed through a heated device where polymerization can take place.

[0053] However, pultrusion and reactive pultrusion make thermoplastic composites, especially those with fiber reinforcement, thermally unstable. In fact, the thermoplastics are heated to high temperatures (i.e. above 150°C) several times during heating times of more than 120 seconds. When thermoforming a thermoplastic composite or exposing it to high temperatures for long periods of time, some important properties such as flexural strength, retention, delamination at the polymer-fiber interface, and even surface degradation of the thermoplastic composite are adversely altered due to the fact that the heating is not uniform (inside / outside of the thermoplastic composite) and is very slow. In fact, the thermoplastic composite may comprise a first region (outside) and a second region (inside). The first and second regions may be different from each other. Preferably, the first region comprises the outside of the thermoplastic composite, including the walls, the outer surface and the outermost region of the thermoplastic composite, according to a first distance depending on the shape of the thermoplastic composite. The second region comprises the inside of the thermoplastic, including the core of the thermoplastic, the inner surface along a second distance depending on the shape of the thermoplastic. Preferably, the first distance starts from the outermost region to the inner surface (excl.) and the second distance starts from the inner surface to the thermoplastic core. The first and second distances may or may not be equal.

[0054]

[0053] In order to overcome these drawbacks, the present invention proposes a new method using a new thermoplastic composite composition. An example of the method according to the present invention is shown in Figure 1. Advantageously, the method 100 comprises a step 110 of providing a thermoplastic composite, a step 120 of heating a part of the thermoplastic composite, a step 130 of creating a folded section in the heated part, and a step 140 of cooling the folded section.

[0055]

[0054] The method according to the present invention includes a step 110 of providing a thermoplastic composite. The thermoplastic composite includes up to 35% by volume of a polymer matrix comprising a (meth)acrylic polymer, and at least 65% by volume of fibers. Such a thermoplastic composite has high heat resistance and significantly reduced changes in mechanical and chemical properties. The thermoplastic composite includes at least 5% by volume of a polymer matrix comprising a (meth)acrylic polymer, and up to 95% by volume of fibers.

[0056] According to one embodiment, the thermoplastic composite may be comprised of 20-30% by volume of polymer matrix and 70-80% by volume of fibers.

[0057] According to another embodiment, the thermoplastic composite may include 25 to 35 percent by volume of a polymer matrix and 65 to 75 percent by volume of fibers.

[0058]

[0057] With regard to the fibres, mention may be made of a plurality of fibres, unidirectional rovings or continuous filament mats, woven fabrics, felts or non-woven fabrics, which may be in the form of strips, wraps, braids, locks or pieces. The fibrous materials of the composites have various forms and dimensions, either one-dimensional, two-dimensional or three-dimensional. The fibrous substances may comprise an assembly of one or more fibres. The fibre material may be of natural or synthetic origin. The fibres of the fibrous substrate may have a diameter between 0.005 μm and 100 μm, preferably between 1 μm and 50 μm, more preferably between 5 μm and 30 μm and advantageously between 10 μm and 25 μm.

[0059] The polymer matrix comprises a (meth)acrylic polymer, preferably the weight average molecular weight of the (meth)acrylic polymer (PI) should be high, ie greater than 50000 g / mol, preferably greater than 100000 g / mol.

[0060]

[0059] The weight average molecular mass can be determined by size exclusion chromatography (SEC).

[0061]

[0060] Regarding the (meth)acrylic monomer (M1), the monomer is selected from alkyl acrylic monomers, alkyl methacrylic monomers, hydroxyalkyl acrylic monomers, hydroxyalkyl methacrylic monomers, and mixtures thereof.

[0062] According to one embodiment, at least 50% by weight, preferably at least 60% by weight, of the (meth)acrylic monomers (M1) is methyl methacrylate.

[0063] According to another embodiment, at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, advantageously at least 80% by weight, even more advantageously at least 90% by weight of the monomer (M1) is a mixture of methyl methacrylate and, optionally, at least one other monomer. Preferably, the at least one other monomer is a (meth)acrylic monomer (M2) selected from compounds containing at least two (meth)acrylic functional groups. The (meth)acrylic monomer (M2) may be present in the (meth)acrylic composition MCI in an amount of 0.01 to 10 phr by weight.

[0064] Advantageously, the (meth)acrylic polymer (PI) is completely soluble in the (meth)acrylic monomer (MI) or in the mixture of (meth)acrylic monomers.

[0065]

[0064] Depending on the embodiment, the thermoplastic composite may be crosslinked, partially crosslinked, or uncrosslinked. Preferably, the thermoplastic composite remains thermoformable.

[0066] The polymerization can typically be carried out at a temperature of less than 140°C, preferably less than 130°C, and more preferably less than 125°C.

[0067] Preferably, the polymerization may be carried out at a temperature between 40°C and 140°C, preferably between 50°C and 130°C, more preferably between 60°C and 125°C.

[0068]

[0067] The thermoplastic composite material according to the present invention has excellent mechanical properties, for example, tensile strength: 1,000 MPa or more.

[0069] Table 1 - Mechanical properties of thermoplastic composites of the present invention containing glass fibers TIFF2025501940000002.tif99170

[0070] The present invention includes a step 120 of heating a portion of the thermoplastic composite.

[0071]

[0070] Preferably, the portion corresponds to a portion of the entire thermoplastic composite being heated. According to an embodiment, the portions may be heated simultaneously or at different times, for example as the composite thermoplastic advances.

[0072]

[0071] The thermoplastic composite portion is softened by heating to facilitate the subsequent process of making the folded portion. As explained, thermoplastic composites are generally solid at room temperature, and are characterized by the fact that they soften as the temperature increases, especially after the glass transition temperature (Tg), and become solid again when the temperature falls below the melting point and / or below the glass transition temperature. The heating process improves the heating rate and the uniformity of the heating.

[0073]

[0072] Heating can be selected from conductive heating, radiative heating, and / or volumetric heating.

[0074]

[0073] According to a first embodiment, the heating step is performed by conductive heating.

[0075]

[0074] Direct contact between the thermoplastic composite and metal can result in conductive heating between the two, and metal is preferably used as the mold and closed mold since metal has a very high thermal conductivity.

[0076] Conductive heating makes it possible to reach a temperature range inside or outside the thermoplastic composite rather than a target temperature.

[0077] According to an embodiment, the temperature ranges are between 160°C and 230°C for the outside temperature of the thermoplastic composite, and between 80°C and 160°C for the inside temperature, preferably at about 250°C for the heat source. Preferably, these ranges are achieved between 10 and 25 seconds for the outside temperature, and between 25 and 50 seconds for the inside temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D13 rod with a diameter of 13 mm.

[0078] According to another embodiment, the temperature ranges are between 140°C and 230°C for the outside temperature of the thermoplastic composite, and between 80°C and 120°C for the inside temperature, preferably with a heat source of about 200°C. Preferably, these ranges are achieved between 10 and 25 seconds for the outside temperature and between 25 and 50 seconds for the inside temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D13 rod with a diameter of 13 mm.

[0079] Advantageously, the duration of heating is 60 seconds or less, preferably 50 seconds or less, more preferably 30 seconds or less, and / or more than 1 second, preferably 5 seconds or more, more preferably 10 seconds or more, for a heat source preferably between 200°C and 250°C, for an outer diameter of the thermoplastic composite of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or for an outer diameter of the thermoplastic composite of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or for an outer diameter of the thermoplastic composite between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0080] Advantageously, the core temperature is between 80° C. and 160° C., preferably between 80° C. and 120° C., and can be reached in 60 seconds or less, preferably 55 seconds or less, more preferably 50 seconds or less, and / or 5 seconds or more, more preferably 10 seconds or more, with a heating source between 200° C. and 250° C. Preferably, these values ​​correspond to the case of thermoplastic composites having an outer diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or of thermoplastic composites with an outer diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or of thermoplastic composites with an outer diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0081] Advantageously, the external temperature is between 140° C. and 230° C., preferably between 140° C. and 180° C., and can be reached in 35 seconds or less, preferably 30 seconds or less, more preferably 25 seconds or less, and / or 1 second or more, more preferably more than 5 seconds, with a heating source preferably between 200° C. and 250° C. Preferably, these values ​​correspond to thermoplastic composites with an external diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or to thermoplastic composites with an external diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or to thermoplastic composites with an external diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0082]

[0081] In the first aspect, conductive heating is always used, but according to another embodiment, the temperature ranges are between 160°C and 240°C on the outside of the thermoplastic composite and between 140°C and 240°C on the inside, preferably the heat source is about 240°C. Preferably these ranges are reached between 10 and 30 seconds. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably P2 with a thickness of 2 mm.

[0083] According to another embodiment, the temperature ranges are between 150°C and 180°C for the outside temperature of the thermoplastic composite and 100°C-180°C for the inside temperature, preferably with a heat source of about 180°C. Preferably, these ranges are reached between 10 and 30 seconds. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably P2, with a thickness of 2 mm.

[0084] Advantageously, the heating time is 95 seconds or less, preferably 90 seconds or less, more preferably 70 seconds or less, even more preferably 60 seconds or less, and / or 1 second or more, preferably 5 seconds or more, more preferably 10 seconds or more, with a heat source of preferably 180° C. to 240° C. Preferably, these values ​​correspond to a thermoplastic composite having a thickness of 30 mm or less, preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less and / or 1 mm or more, more preferably 1.5 mm or more, and / or a thermoplastic thickness between 1 mm and 30 mm, preferably between 1.5 mm and 20 mm, more preferably between 2 mm and 16 mm.

[0085] Advantageously, the core temperature may be between 100° C. and 240° C., preferably between 140° C. and 180° C., for a time of 45 seconds or less, preferably 40 seconds or less, more preferably 35 seconds or less, even more preferably 30 seconds or less, and / or 2 seconds or more, with a heating source preferably between 180° C. and 240° C. Preferably, these values ​​correspond to a thermoplastic composite having a thickness of 30 mm or less, preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less and / or 1 mm or more, more preferably 1.5 mm or more, and / or a thermoplastic thickness of between 1 mm and 30 mm, preferably between 1.5 mm and 20 mm, more preferably between 2 mm and 16 mm.

[0086] Advantageously, the external temperature may be between 150° C. and 240° C., preferably between 160° C. and 180° C., for a time of 45 seconds or less, preferably 40 seconds or less, more preferably 35 seconds or less, even more preferably 30 seconds or less, and / or 2 seconds or more, more preferably 5 seconds or more, with a heating source preferably between 180° C. and 240° C. Preferably, these values ​​correspond to a thermoplastic composite having a thickness of 30 mm or less, preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less and / or 1 mm or more, more preferably 1.5 mm or more, and / or a thermoplastic thickness of between 1 mm and 30 mm, preferably between 1.5 mm and 20 mm, more preferably between 2 mm and 16 mm.

[0087] Conductive heating is faster than convection heating (i.e., with convection heating, if the heat source is 200°C, and the inside temperature is 180°C, it will heat up in 15 minutes). In fact, typically with convection heating, the heating time is very slow, 10 minutes or more, and the heating is non-uniform, i.e., the core temperature is heated until it reaches a temperature high enough to bend the thermoplastic composite, and the surface of the thermoplastic deteriorates (deteriorating its chemical and mechanical properties), or if the outer surface does not deteriorate, the core temperature is insufficient to bend the thermoplastic composite.

[0088]

[0087] The heating time and / or heating temperature can be selected depending at least on the thickness of the thermoplastic composite, and / or on the diameter (outer or inner diameter), and / or on the target core temperature or outer (surface) target temperature and / or the desired heating time. The heating temperature and / or heating time can depend, for example, on the temperature of the heat source and / or the temperature of the metal of the mold.

[0089]

[0088] Preferably, the temperature difference between the inner and outer temperatures during the heating step may be 95°C or less, preferably 80°C or less, more preferably 70°C or less, even more preferably 60°C or less for 95 seconds or less of heating, preferably 80 seconds or less of heating, more preferably 60 seconds or less of heating, and / or for 1 second or more of heating, preferably 10 seconds or more of heating. Preferably, the temperature difference between the inner and outer temperatures during the heating step may be 0°C or more, preferably 1°C or more, more preferably 2°C or more, even more preferably 5°C or more for 95 seconds or less of heating, preferably 80 seconds or less of heating, more preferably 60 seconds or less of heating, and / or for more than 1 second of heating, preferably 10 seconds or more of heating.

[0090]

[0089] Preferably the inside temperature is between 160°C and 180°C.

[0091]

[0090] According to a second embodiment, the heating may be radiative heating.

[0092]

[0091] Radiation heating may be performed by infrared (IR), preferably including near infrared and mid infrared. IR is faster than convection and conduction. Preferably, the heating step is radiation heating, more preferably infrared heating. Indeed, near infrared (NIR) or mid infrared (MIR) is more preferred for heating, and the heating source is preferably 20-70 kW / m for NIR. 2 , preferably 45 to 65 kW / m 2 , 30-60kW / m for MIR 2 , more preferably 45 to 55 kW / m 2 It is.

[0093]

[0092] By using IR heating, the heating time can be reduced to 100 seconds or less, preferably 90 seconds or less, more preferably 60 seconds or less, and even more preferably 30 seconds or less. This allows the center temperature to reach about 180°C when the outer temperature is 200-250°C in one embodiment of the present invention, and the heating becomes more uniform.

[0094]

[0093] Table 2-Heating time (seconds) TIFF2025501940000003.tif33170

[0095] Table 2 discloses some heating time values ​​depending on the composite (e.g. rod or panel) and heating source (NIR or MIR) to reach an outside temperature of 200° C.-250° C. and a core temperature of 180° C. Regardless of the shape and homogeneity of the thermoplastic composite, IR heating is faster than convection heating and allows a core temperature of about 180° C. and an outside temperature of 200° C.-250° C. to be reached.

[0096] According to an embodiment of the second aspect of the present invention, the temperature range is between 80°C and 240°C for the outer temperature of the thermoplastic composite and 140°C to 200°C for the inner temperature, preferably the heat source is about Q=3.5·10 7 W m -3 Preferably, these ranges are achieved between 10 and 25 seconds for outside temperature and between 25 and 50 seconds for room temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D13 rod having a diameter of 13 mm.

[0097] According to another embodiment, the temperature range is between 60° C. and 160° C. for the outer temperature of the thermoplastic composite and between 90° C. and 130° C. for the inner temperature, preferably the heat source has a Q of 2.10 7 W m -3Preferably, these ranges are achieved between 10 and 25 seconds for the outer temperature and between 25 and 50 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D13 rod having a diameter of 13 mm.

[0098] Advantageously, the duration of heating is preferably Q=3.5.10 7 W m -3 and Q=2.10 7 W m -3 and for an outer diameter of the thermoplastic composite of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or for an outer diameter of the thermoplastic composite of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or for an outer diameter of the thermoplastic composite between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm, the heating time is 60 seconds or less, preferably 55 seconds or less, more preferably 50 seconds or less, and / or more than 1 second, preferably 5 seconds or more.

[0099] Advantageously, the core temperature is between 90° C. and 200° C., preferably between 100° C. and 140° C., and Q=3.5.10 7 W m -3 and Q=2.10 7 W m -3 and / or in 60 seconds or less, preferably 55 seconds or less, more preferably 50 seconds or less, and / or 5 seconds or more, more preferably 10 seconds or more, with a heat source between 0.01 and 0.05 mm. Preferably, these values ​​correspond to thermoplastic composites with an outer diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or thermoplastic composites with an outer diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or thermoplastic composites with an outer diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0100] Advantageously, Q=3.5·10 7 W m -3 and Q=2·10 7 W m -3With a heating source between 0° C. and 240° C., advantageously the external temperature is between 60° C. and 240° C., preferably between 80° C. and 160° C., and can be reached in 30 seconds or less, preferably 25 seconds or less, and / or more than 1 second, more preferably 5 seconds or more. Preferably, these values ​​correspond to thermoplastic composites with an external diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or thermoplastic composites with an external diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or thermoplastic composites with an external diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0101] According to another embodiment of the second aspect, the temperature range is preferably about 47 kW·m 2 With an IRM source of this type, the thermoplastic composite may have an outer temperature of between 150°C and 210°C and an inner temperature of between 150°C and 200°C. Preferably, these ranges are achieved between 25 and 50 seconds for the outer temperature and between 50 and 95 seconds for the room temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D16 rod with a diameter of 13 mm.

[0102] According to another embodiment, the temperature range is between 40° C. and 220° C. on the outside of the thermoplastic composite and 40° C. to 180° C. on the inside, preferably with an IRC source of about 50 kW m 2 Preferably, these ranges are achieved between 10 and 80 seconds for outside temperature and between 10 and 80 seconds for indoor temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D16 rod having a diameter of 13 mm.

[0103] According to another embodiment shown in FIG. 2, the temperature range is between 40° C. and 200° C. on the outside of the thermoplastic composite and 40° C.-190° C. on the inside, and preferably the IR source is about 50 kW m 2 and 65 kW·m 2Preferably, these ranges are achieved between 1 and 80 seconds for outside temperature and between 1 and 80 seconds for indoor temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D16 rod with a diameter of 13 mm.

[0104]

[0103] Some values ​​using a 13mm diameter D16 rod and an IR light source are given in Table 3 below.

[0105] Table 3 - Heating time and surface and center temperatures of a D16 rod with a diameter of 13 heated by near infrared light TIFF2025501940000004.tif71170

[0106] Advantageously, the heating time is less than 95 seconds, preferably less than 60 seconds, with an inner temperature of the thermoplastic composite less than 180° C. Furthermore, the temperature difference between the inner and outer temperatures is less than 80° C., preferably less than 70° C., more preferably less than 60° C., even more preferably less than 50° C., and is greater than 5° C., preferably greater than 10° C., with heating for less than 95 seconds, preferably less than 90 seconds, more preferably less than 80 seconds, even more preferably less than 60 seconds.

[0107]

[0106] Advantageously, the duration of heating is preferably 47 kW m 2 and 65 kW·m 2 for an outer diameter of the thermoplastic composite of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or for an outer diameter of the thermoplastic composite of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or for an outer diameter of the thermoplastic composite between 2 and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm, for a heating source between 95 seconds or less, preferably 80 seconds or less, more preferably 60 seconds or less, and / or more than 1 second, preferably 5 seconds or more, more preferably 10 seconds or more.

[0108]

[0107] Advantageously, the outside temperature is 47 kW·m 2 and 65 kW·m 2with a heating source between 40°C and 200°C, preferably between 80°C and 180°C, and can be reached in 95 seconds or less, preferably 80 seconds or less, more preferably 60 seconds or less, and / or 5 seconds or more, more preferably 10 seconds or more. Preferably, these values ​​correspond to thermoplastic composites having an outer diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or thermoplastic composites with an outer diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or thermoplastic composites with an outer diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0109]

[0108] Advantageously, the inside temperature is preferably 47 W·m 2 and 65 W·m 2 with a heating source between 40° C. and 200° C., preferably between 70° C. and 180° C., in 95 seconds or less, preferably 80 seconds or less, more preferably 60 seconds or less, and / or more than 1 second, more preferably 10 seconds or more. Preferably, these values ​​correspond to thermoplastic composites having an outer diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or thermoplastic composites with an outer diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or thermoplastic composites with an outer diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0110] According to another embodiment, the temperature range is preferably such that the heat source Q=2.5 7 W m -3 for the outer temperature of the thermoplastic composite between 80°C and 240°C and for the inner temperature between 80°C and 240°C. Preferably, these ranges are reached between 10 and 30 seconds. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P2 panel having a thickness of 2 mm.

[0111] According to another embodiment, the temperature range is preferably Q=1.75·10 7 W m -3With a heating source of 100° C., the thermoplastic composite may have an outer temperature of between 70° C. and 180° C. and an inner temperature of between 70° C. and 180° C. Preferably, these ranges are reached between 10 and 30 seconds. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P2 panel having a thickness of 2 mm.

[0112]

[0111] According to another embodiment, the temperature range is preferably about 47 kW m 2 where the thermoplastic composite has an outer temperature between 100°C and 220°C and an inner temperature between 70°C and 180°C. Preferably, these ranges are achieved between 10 and 40 seconds for the outer temperature and between 10 and 40 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P4 panel having a thickness of 4mm.

[0113] According to another embodiment shown in FIG. 3, the temperature range is preferably set at about 50 kW·m 2 ~65kW m 2 wherein the thermoplastic composite has an outer temperature between 110°C and 220°C and an inner temperature between 70°C and 210°C. Preferably, these ranges are achieved between 10 and 30 seconds for the outer temperature and between 10 and 40 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P4 panel having a thickness of 4mm.

[0114]

[0113] Below are some values ​​with an IR light source for a P4 panel with a thickness of 4 mm.

[0115]

[0114] Table 4 - Heating time and top, bottom and center temperatures of P4 panel heated by near infrared rays TIFF2025501940000005.tif74170

[0116] Advantageously, the heating time is Q=1.75·10 7 W m -3 and Q=2.5 107 W m -3 or 47kW·m 2 and 65 kW·m 2 and for a heating source between 40 seconds or less, preferably 35 seconds or less, more preferably 30 seconds or less, and / or more than 1 second, preferably 5 seconds or more, for a thermoplastic composite thickness of 30 mm or less, preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less, and / or more than 1 mm, more preferably 1.5 mm or more, and / or a thermoplastic resin thickness between 1 mm and 30 mm, preferably between 1.5 mm and 20 mm, more preferably between 2 mm and 16 mm.

[0117] Advantageously, the core temperature and the outer temperature are such that Q=1.75·10 7 W m -3 and Q=2.5 10 7 W m -3 or 47kW·m 2 and 65 kW·m 2 with a heating source between 70°C and 240°C, preferably between 80°C and 220°C, more preferably between 90°C and 180°C, and can be reached in 40 seconds or less, preferably 30 seconds or less, more preferably 25 seconds or less, even more preferably 20 seconds or less and / or more than 1 second, more preferably 5 seconds or more. Preferably, these values ​​correspond to a thermoplastic composite having a thickness of 30 mm or less, preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less and / or 1 mm or more, more preferably 1.5 mm or more, and / or a thermoplastic thickness of 1 mm to 30 mm, preferably 1.5 mm to 20 mm, more preferably 2 mm to 16 mm.

[0118]

[0117] Radiation heating allows for improved (i.e., shorter) heating duration and allows for sufficient uniform heating up to the central zone in a relatively short time without the outer surfaces becoming too hot and degrading the material.

[0119]

[0118] The heating time and / or heating temperature can be selected depending at least on the thickness of the thermoplastic composite, and / or on the diameter (inner or outer diameter), and / or on the target core temperature and / or on the outer (surface) target temperature and / or on the desired heating time. The heating temperature and / or heating time depends on the wavelength range of the irradiation and / or the irradiation power.

[0120]

[0119] Note that in the case of IR heating, the heat source can be either a surface power (e.g. the power of an IR lamp) or a volumetric heat source. Those skilled in the art know the difference and which type of surface or volume source to use.

[0121]

[0120] Preferably, the temperature difference between the inner and outer temperatures during the heating step may be 95°C or less, preferably 80°C or less, more preferably 70°C or less, even more preferably 60°C or less for 95 seconds or less of heating, preferably 80 seconds or less, more preferably 60 seconds or less of heating, and / or 1 second or more of heating, preferably 10 seconds or more of heating. Preferably, the temperature difference between the inner and outer temperatures during the heating step may be 0°C or more, preferably 1°C or more, more preferably 2°C or more, even more preferably 5°C or more for 95 seconds or less of heating, preferably 80 seconds or less, more preferably 60 seconds or less of heating, and / or 1 second or more of heating, preferably 10 seconds or more of heating.

[0122]

[0121] In accordance with another aspect of the invention, the heating step can include volumetric heating.

[0123]

[0122] The volumetric heating may include microwaves. The microwave power is 1 KW or more, preferably 5 KW or more, more preferably 10 KW or more. Preferably, the microwave power is 30 KW or less, preferably 25 KW or less, more preferably 20 KW or less. The frequency may be 900 MHz or more, preferably 1 GHz or more, more preferably 1.5 GHz or more, more preferably 2 GHz or more. The frequency is 8 GHz or less, preferably 7 GHz or less, more preferably 6 GHz or less. In a preferred embodiment, the frequency is 2.45 GHZ and the microwave power is 1 kW.

[0124]

[0123] The heating time and / or heating temperature can be selected depending at least on the thickness of the thermoplastic composite, or on the outer diameter, or on the target core temperature or the outer (surface) target temperature or the desired heating time. The heating temperature and / or heating time will vary depending on the frequency and / or microwave power.

[0125] According to one embodiment, the temperature range is between 140° C. and 230° C. for the outer temperature of the thermoplastic composite and between 140° C. and 230° C. for the inner temperature, preferably with a heating source of Q=2·10 7 W m -3 Preferably, these ranges are achieved between 10 and 25 seconds for the outer temperature and between 10 and 25 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D13 rod having a diameter of 13 mm.

[0126] According to another embodiment, the temperature range is between 100° C. and 180° C. for the outer temperature of the thermoplastic composite and between 100° C. and 180° C. for the inner temperature, preferably the heat source is Q=1.3·10 7 W m -3 Preferably, these ranges are achieved between 10 and 25 seconds for the outer temperature and between 10 and 25 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D13 rod having a diameter of 13 mm.

[0127] According to another embodiment, the temperature range is between 120°C and 230°C for the outer temperature of the thermoplastic composite and between 120°C and 230°C for the inner temperature, preferably the heat source is Q=2·10 7 W m -3 Preferably, these ranges are achieved between 10 and 25 seconds for the outer temperature and between 10 and 25 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D30 rod with a diameter of 30 mm.

[0128] According to another embodiment, the temperature range is preferably Q=1.3·10 7 W m -3 With a heating source of 100° C., the thermoplastic composite can have an outer temperature between 100° C. and 180° C., and an inner temperature between 100° C. and 180° C. Preferably, these ranges are reached between 10 and 25 seconds. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite rod, more preferably a D30 rod with a diameter of 30 mm.

[0129] Advantageously, the duration of heating is Q=1.0.10 7 W m -3 and Q=3.10 7 W m -3 between, preferably Q=1.3.10 7 W m -3 and Q = 2.107 W m -3 and for a heat source between 0.5 and 10 mm, and an outer diameter of the thermoplastic composite is 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or an outer diameter of the thermoplastic composite is 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or an outer diameter of the thermoplastic composite is between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm, the duration of heating is 30 seconds or less, preferably 25 seconds or less, more preferably 20 seconds or less, and / or more than 1 second, preferably 5 seconds or more.

[0130] Advantageously, the core temperature is Q=1.0·10 7 W m -3 and Q=3·10 7 W m -3 , preferably Q=1.3 10 7 W m -3 and Q=2·10 7 W m -3 and the temperature is between 100° C. and 230° C., preferably between 120° C. and 180° C., and is reached in 30 seconds or less, preferably 25 seconds or less, more preferably 20 seconds or less and / or more than 1 second, more preferably 5 seconds or more. Preferably, these values ​​correspond to thermoplastic composites having an outer diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or thermoplastic composites with an outer diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or for thermoplastic composites with an outer diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0131] Advantageously, the outside temperature is Q=1.0.10 7 W m -3 and Q=3·10 7 W m -3 , preferably Q=1.3 10 7 W m -3 and Q=2·10 7 W m -3 and between 100° C. and 230° C., preferably between 120° C. and 180° C., and reached in 25 seconds or less, preferably 20 seconds or less, more preferably 15 seconds or less and / or more than 1 second, more preferably 5 seconds or more. Preferably, these values ​​correspond to thermoplastic composites having an outer diameter of 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less, and / or thermoplastic composites with an outer diameter of 2 mm or more, preferably 4 mm or more, more preferably 6 mm or more, and / or for thermoplastic composites with an outer diameter between 2 mm and 30 mm, preferably between 4 mm and 25 mm, more preferably between 6 mm and 20 mm.

[0132] According to an embodiment of this aspect of the invention, the temperature range is preferably about Q=1.9.10 7 W m -3 With a heating source of 100° C. and 220° C. for the outer temperature of the thermoplastic composite, and 100° C. to 220° C. for the inner temperature. Preferably, these ranges are reached between 10 and 25 seconds. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P2 panel having a thickness of 2 mm.

[0133] According to another embodiment, the temperature range is between 90°C and 180°C for the outer temperature of the thermoplastic composite and between 90°C and 180°C for the inner temperature, preferably the heat source is Q=1.4·10 7 W m -3 Preferably, these ranges are achieved between 10 and 25 seconds for the outer temperature and between 10 and 25 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P2 panel having a thickness of 2 mm.

[0134] According to another embodiment, the temperature range is preferably Q=1.9·10 7 W m -3 With a heating source of 100° C., the outer temperature of the thermoplastic composite can be between 100° C. and 220° C., and the inner temperature can be between 100° C. and 220° C. Preferably, these ranges are reached between 10 and 30 seconds. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P4 panel having a thickness of 4 mm.

[0135] According to another embodiment, the temperature range is between 90°C and 180°C for the outer temperature of the thermoplastic composite and between 90°C and 180°C for the inner temperature, preferably the heat source is Q=1.4·10 7 W m -3Preferably, these ranges are achieved between 10 and 30 seconds for the outer temperature and between 10 and 30 seconds for the inner temperature. In one example of this embodiment, the thermoplastic composite is a thermoplastic composite panel, more preferably a P4 panel having a thickness of 4 mm.

[0136] Advantageously, the duration of heating is Q=1.0·10 7 W m -3 and Q=3.0 10 7 W m -3 , preferably Q=1.4 10 7 W m -3 and Q=1.9 10 7 W m -3 and for a thermoplastic composite thickness of 30 mm or less, preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less and / or more than 1 mm, more preferably 1.5 mm or more, and / or for a thermoplastic composite thickness between 1 mm and 30 mm, preferably between 1.5 mm and 20 mm, more preferably between 2 mm and 16 mm, for a heating source of 95 seconds or less, preferably 60 seconds or less, more preferably 30 seconds or less, even more preferably 20 seconds or less and / or more than 1 second, preferably 5 seconds or more.

[0137] Advantageously, the core temperature and / or the outer temperature are such that Q=1.0·10 7 W m -3 and Q=3.0 10 7 W m -3 , preferably Q=1.4 10 7 W m -3 and Q=1.9 10 7 W m -3with a heating source between 90°C and 220°C, preferably between 100°C and 180°C, and can be reached in 30 seconds or less, preferably 25 seconds or less, more preferably 20 seconds or less, even more preferably 15 seconds or less, and / or more than 1 second, more preferably 5 seconds or more. Preferably, these values ​​correspond to a thermoplastic composite having a thickness of 30 mm or less, preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less and / or 1 mm or more, more preferably 1.5 mm or more, and / or a thermoplastic resin thickness of between 1 mm and 30 mm, preferably between 1.5 mm and 20 mm, more preferably between 2 mm and 16 mm.

[0138]

[0137] Preferably, the temperature difference between the inner and outer temperatures during the heating step may be 95°C or less, preferably 80°C or less, more preferably 70°C or less, even more preferably 60°C or less for 95 seconds or less of heating, preferably 80 seconds or less of heating, more preferably 60 seconds or less of heating, and / or 1 second or more of heating, preferably 10 seconds or more of heating. Preferably, the temperature difference between the inner and outer temperatures during the heating step may be 0°C or more, preferably 1°C or more, more preferably 2°C or more, even more preferably 5°C or more for 95 seconds or less of heating, preferably 80 seconds or less of heating, more preferably 60 seconds or less of heating, and / or for more than 1 second of heating, preferably 10 seconds or more of heating.

[0139] According to another aspect of the invention, the heating step may include establishing a formula with upper and lower limits for time and temperature to be reached. The formula may include several variables such as a function of diameter, and / or heat source, and / or dimensions, and / or composition of the thermoplastic composite, and / or geometry of the thermoplastic composite.

[0140] Advantageously, the heating time is less than or equal to 95 seconds, preferably less than or equal to 60 seconds, and preferably the inner temperature of the thermoplastic composite is less than or equal to 180°C.

[0141]

[0140] It may be noted that in the case of volumetric heating, the heat source can be either a surface heat source or a volumetric heat source. Those skilled in the art know the difference and which type of surface or volume source to use.

[0142]

[0141] The method of the present invention includes a step 130 of creating a folded section in the heated portion by folding the heated portion.

[0143]

[0142] The heated thermoplastic composite allows the heated portion to be formed into different shapes. The process of creating folded sections allows the shape of the thermoplastic composite to be altered.

[0144]

[0143] The thermoplastic composite is preferably linear and the heated section can be formed by a process of creating a folded section. Creating a folded section can be a fold, a bend, a complex shape, or a combination of any of the above.

[0145]

[0144] In the case of sections having bent portions, the bent portions may be from an angle within the range of, for example, 5° to 180°, 5° to 135°, or 10° to 90°.

[0146]

[0145] Creating a bend can be accomplished by simple bending, compression bending, folding and / or twisting. Preferably, creating a bend comprises twisting.

[0147]

[0146] Simple folding involves compression of the inner fibers and tension of the outer fibers. The folding can be accomplished by a fixed tool, weight on both sides of the thermoplastic composite, or a die.

[0148]

[0147] Compression preferably includes pre-stress tension to reduce path length and potential cracking. Preferably, compression is prior to bending. According to one embodiment, compression results in an elliptical shape that can be curved more easily. Compression may include pressing and / or molding.

[0149] According to an embodiment, the step of creating the curvature may comprise the step of applying a pressure to the heated portion, the pressure being between 1 bar and 150 bar, preferably between 3 bar and 100 bar, more preferably between 5 bar and 50 bar.

[0150]

[0149] Pressure is applied for between 30 seconds and 20 minutes, preferably between 1 and 10 minutes.

[0151]

[0150] Twisting ensures that the path length of all fibers in the thermoplastic composite is uniform. Also, buckling and cracking do not occur. Twisting can be prior to folding. Twisting can follow a twist degree between 150° and 360°, preferably at least 360°. For example, the fibers can be coupled to a rotary motor to induce a uniform and homogenous twist in the fibers.

[0152]

[0151] The method of the present invention includes the step 140 of cooling the folded section to solidify and form a folded thermoplastic composite.

[0153]

[0152] Preferably, the cooling step is performed at a cooling temperature and / or cooling duration. According to one embodiment, the cooling temperature and / or cooling time can be selected depending on the glass transition temperature (Tg) of the folded thermoplastic composite. The Tg can be less than 130°C, preferably less than 120°C, more preferably less than 110°C. According to another embodiment, the cooling temperature and / or cooling time can be selected depending on the dimensions of the folded thermoplastic composite, the heating temperature, the heating time, the type of heating, the number of bends, the type of bends, and / or the shape of the thermoplastic composite.

[0154]

[0153] According to another embodiment, the cooling temperature and / or cooling period may be determined according to the cooling rate, for example, for a D13 rod with a diameter of 13 mm, the cooling rate is 0.1°C / s, 0.2°C / s, 0.3°C / s, 0.4°C / s, 0.5°C / s, 0.6°C / s, 0.7°C / s, 0.8°C / s, 0.9°C / s, preferably 0.2°C / s.

[0155]

[0154] For example, the cooling temperature may be 150°C or less, preferably 130°C or less, more preferably 110°C or less, and even more preferably 100°C or less. The cooling temperature may be 50°C or more, preferably 60°C or more, more preferably 70°C or more, and even more preferably 80°C or more. The cooling temperature may be between 50°C and 150°C, preferably between 60°C and 130°C, more preferably between 70°C and 130°C, and even more preferably between 80°C and 110°C.

[0156]

[0155] In practice, the temperature difference between the core temperature and the outer temperature can be controlled and / or monitored to curve the thermoplastic composite without degrading the mechanical and chemical properties. If the core temperature is too high, the outermost layer and the surface of the thermoplastic composite will deteriorate. If the core temperature is not high enough, the curve cannot be processed. To maintain the mechanical and chemical properties, the curve is preferably uniform.

[0157] Advantageously, the temperature difference between the inner and outer temperatures of the thermoplastic composite, preferably of the folded section of the thermoplastic composite, and between the heating and cooling steps or steps of making the folded section is not more than 50° C., preferably not more than 40° C., more preferably not more than 20° C. The temperature delta may be 0° C. or more, preferably not less than 5° C., more preferably not less than 7° C. The temperature difference between the heating and cooling steps may be between 0° C. and 50° C., preferably between 5° C. and 40° C., more preferably between 7° C. and 20° C.

[0158] The temperature difference is reached in 390 seconds or less, preferably 120 seconds or less, more preferably 60 seconds or less, even more preferably 50 seconds or less. The temperature difference is reached in 5 seconds or more or less, preferably 10 seconds or more, more preferably 15 seconds or more, even more preferably 20 seconds or more. Advantageously, the temperature difference is reached between 10 and 390 seconds, preferably between 15 and 120 seconds, even more preferably between 15 and 60 seconds.

[0159]

[0158] Preferably, after heating for 60 seconds, preferably heating for 30 seconds, and then cooling to a temperature of 150°C or less, the temperature differential within the thermoplastic composite (inside and outside temperatures of the thermoplastic composite) is reached in 390 seconds or less, preferably 200 seconds or less, more preferably 120 seconds or less, and even more preferably 90 seconds or less.

[0160]

[0159] Preferably, for bending thermoplastics, the target core temperature is between 110°C and 210°C, preferably between 120°C and 200°C, more preferably between 130°C and 190°C, and even more preferably between 160°C and 180°C.

[0161]

[0160] Preferably, in order not to degrade the surface of the thermoplastic polymer, the target outer temperature may be between 200°C and 250°C, preferably between 210°C and 245°C, more preferably between 220°C and 240°C, and even more preferably between 220°C and 230°C.

[0162]

[0161] According to the embodiment shown in Figures 2 and 3, the curvature can be achieved when the curve of the outer temperature and the curve of the inner temperature cross, i.e. when the temperature difference at the intersection of the two curves is less than 50 degrees and the preferred conditions disclosed above are fulfilled. In fact, the outer temperature starts to drop (cooling phase) and the inner temperature stabilizes. A low temperature difference is therefore preferred. Furthermore, thanks to the invention (composition, shape and heating method of the thermoplastic composite), the temperature difference is reached quickly and therefore the method is faster. This reduces the production costs, since degradation of the mechanical and chemical properties in particular, but also surface degradation, long production times are avoided.

[0163]

[0162] The bending may depend on the shape of the thermoplastic composite.

[0164]

[0163] For example, for a bendable thermoplastic composite rod with an outer diameter between 5 mm and 30 mm, the target core temperature may be between 160°C and 180°C, for between 30 and 90 seconds, preferably less than 60 seconds and / or more than 5 seconds.

[0165]

[0164] For example, for a thermoplastic composite panel between 5mm and 10mm thick, the target core temperature may be between 160°C and 180°C, for between 30 seconds and 90 seconds, preferably less than 30 seconds and / or more than 5 seconds.

[0166]

[0165] Heating parameters to reach 160-240°C in 30 seconds. After 30 seconds of heating, T min >The temperature difference in a thermoplastic composite after cooling at 150°C until the temperature reaches 150°C after the cooling time.

[0167] Table 5 - Temperature difference T between heating and cooling steps for different composites and heating means TIFF2025501940000006.tif85170

[0168]

[0167] The heating time of convection heating is longer than that of conduction heating, radiation heating, and volumetric heating. Furthermore, the cooling time to reach 150°C is comparable among convection, conduction, radiation, and volumetric heating. Furthermore, unlike conduction, radiation, or volumetric heating, convection heating has a very large temperature difference during heating, and the temperature difference during cooling is comparable among conduction, radiation, and volumetric heating.

[0169]

[0168] Mechanical properties (especially resin degradation), bending, an example of degradation of a bent thermoplastic composite containing at least 65% fibers is reached in 90 seconds or less, preferably 60 seconds or less, depending on the geometry of the thermoplastic composite, when the core temperature of the thermoplastic composite is between 160°C and 180°C.

[0170] Table 6 - Properties of different composites heated by volumetric heating TIFF2025501940000007.tif56170

[0171]

[0170] Table 7 - Heating characteristics of various composite materials by radiant heating TIFF2025501940000008.tif56170

[0172] Table 8 - Properties of different composites heated by convection heating TIFF2025501940000009.tif56170

[0173] Table 9 - Properties of different composites heated by conductive heating TIFF2025501940000010.tif56170

[0174]

[0173] The numbers in Tables 6 to 9 have the following meanings: 0: not present or insufficient, ~5: present or sufficient, .na: not applicable

[0175]

[0174] Convection heating is much slower to reach the target temperatures inside and outside so that the thermoplastic composite can be bent. Furthermore, convection bending is not possible with the set time target, and fibers will crack and bulking will occur.

[0176]

[0175] Advantageously, the method of the invention may include the steps of welding, cutting, gluing or laminating.

[0177]

[0176] According to another aspect, the present invention comprises the manufacture of a thermoplastic composite. Preferably, a thermoplastic composite according to the present invention.

[0178]

[0177] In one embodiment, the thermoplastic composite is a (meth)acrylic-based thermoplastic composite, which means that the polymer matrix of the thermoplastic composite comprises or is composed of a (meth)acrylic polymer.

[0179]

[0178] The polymer matrix can be made from a liquid composition a) or a (meth)acrylic polymer (PI), comprising a (meth)acrylic monomer (MI) or from a (meth)acrylic syrup.

[0180]

[0179] The liquid (meth)acrylic syrup of the present invention comprises between 10% and 50% by weight of (meth)acrylic polymer (PI) and between 50% and 90% by weight of (meth)acrylic monomer (MI). Preferably, the liquid (meth)acrylic syrup comprises between 10% and 40% by weight of (meth)acrylic polymer (PI) and between 60% and 90% by weight of (meth)acrylic monomer (MI), more preferably between 10% and 30% by weight of (meth)acrylic polymer (PI) and between 70% and 90% by weight of (meth)acrylic monomer (MI).

[0181] The dynamic viscosity of the liquid composition a) or (meth)acrylic syrup is in the range of 10 mPa·s to 10000 mPa·s, preferably 20 mPa·s to 7000 mPa·s, advantageously 20 mPa·s to 5000 mPa·s, more advantageously between 20 mPa·s and 2000 mPa·s, even more advantageously between 20 mPa·s and 1000 mPa·s. The viscosity of the syrup can be easily measured with a rheometer or viscometer. The dynamic viscosity is measured at 25°C. If the liquid (meth)acrylic syrup exhibits Newtonian behavior, i.e., no shear thinning, the dynamic viscosity is independent of the shear of the rheometer and the movement speed of the viscometer. If the liquid composition LC1 exhibits non-Newtonian behavior, i.e., shear thinning, the dynamic viscosity is measured at 25°C and at a shear rate Is<-1>.

[0182]

[0181] The liquid composition a) of the present invention comprises a (meth)acrylic monomer (M1) and a (meth)acrylic polymer (PI). Upon polymerization, the (meth)acrylic monomer (M1) is converted into a (meth)acrylic polymer (P2) comprising monomer units of the (meth)acrylic monomer (M1) and possible other monomers.

[0183]

[0182] Preferably, the kinematic viscosity of the (meth)acrylic composition MCI is also in the range of 10 mPa·s to 10000 mPa·s, preferably 20 mPa·s to 7000 mPa·s, advantageously 20 mPa·s to 5000 mPa·s, more advantageously between 20 mPa·s and 2000 mPa·s, and even more advantageously between 20 mPa·s and 1000 mPa·s.

[0184]

[0183] As regards the (meth)acrylic polymer (PI), mention may be made of polyalkyl methacrylates or polyalkyl acrylates. According to a preferred embodiment, the (meth)acrylic polymer (PI) is polymethyl methacrylate (PMMA).

[0185]

[0184] According to one embodiment, the methyl methacrylate (MMA) homopolymer or copolymer comprises at least 70% by weight, preferably at least 80% by weight, advantageously at least 90% by weight, and even more advantageously at least 95% by weight of methyl methacrylate.

[0186]

[0185] According to another embodiment, the PMMA is a mixture of at least one homopolymer and at least one copolymer of MMA, or a mixture of at least two homopolymers or two copolymers of MMA having different average molecular weights, or a mixture of at least two copolymers of MMA having different monomer compositions.

[0187]

[0186] Copolymers of methyl methacrylate (MMA) contain 70% to 99.9% by weight of methyl methacrylate and 0.1% to 30% by weight of at least one monomer containing at least one ethylenic unsaturation copolymerizable with methyl methacrylate.

[0188]

[0187] These monomers are well known and include in particular acrylic acid, methacrylic acid, and alkyl (meth)acrylates in which the alkyl group has 1 to 12 carbon atoms. Examples include methyl acrylate, ethyl, butyl, or 2-ethylhexyl (meth)acrylate. Preferably, the comonomer is an alkyl acrylate in which the alkyl group has 1 to 4 carbon atoms.

[0189] According to a first preferred embodiment, the copolymer of methyl methacrylate (MMA) comprises 80% to 99.9% by weight, advantageously 85% to 99.9% by weight, more advantageously 90% to 99.9% by weight of methyl methacrylate and 0.1% to 20% by weight, advantageously 0.1% to 10% by weight, more advantageously 0.1% to 10% by weight of at least one monomer containing at least one ethylenic unsaturation copolymerizable with methyl methacrylate. Preferably, the comonomer is selected from methyl acrylate and ethyl acrylate, and mixtures thereof.

[0190]

[0189] The weight average molecular weight of the (meth)acrylic polymer (PI) should be high, ie, greater than 50000 g / mol, preferably greater than 100000 g / mol.

[0191]

[0190] The weight average molecular mass can be determined by size exclusion chromatography (SEC).

[0192]

[0191] The (meth)acrylic polymer (PI) dissolves completely in the (meth)acrylic monomer (MI) or mixture of (meth)acrylic monomers. This allows the viscosity of the (meth)acrylic monomer (M1) or mixture of (meth)acrylic monomers to be increased. The resulting solution is a liquid composition commonly called a "syrup" or "prepolymer". The dynamic viscosity value of the liquid (meth)acrylic syrup is between 10 mPa·s and 10000 mPa·s. The viscosity of the syrup can be easily measured with a rheometer or viscometer. The dynamic viscosity is measured at 25°C.

[0193]

[0192] Advantageously, the liquid (meth)acrylic composition or syrup does not contain additional voluntarily added solvents.

[0194]

[0193] With regard to the (meth)acrylic monomer (M1), the monomer is selected from alkyl acrylic monomers, alkyl methacrylic monomers, hydroxyalkyl acrylic monomers, hydroxyalkyl methacrylic monomers, and mixtures thereof.

[0195]

[0194] Preferably, the (meth)acrylic monomer (M1) is selected from hydroxyalkyl acrylic monomers, hydroxyalkyl methacrylic monomers, alkyl acrylic monomers, alkyl methacrylic monomers and mixtures thereof, the alkyl group containing 1 to 22 linear, branched or cyclic carbons, preferably the alkyl group containing 1 to 12 linear, branched or cyclic carbons.

[0196]

[0195] More preferably, the (meth)acrylic monomer (M1) is selected from alkyl acrylic or alkyl methacrylic monomers and mixtures thereof, the alkyl group containing 1 to 22 linear or cyclic carbons, preferably the alkyl group containing 1 to 12 linear, branched or cyclic carbons.

[0197] Advantageously, the (meth)acrylic monomer (M1) is selected from methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, methacrylic acid, acrylic acid, n-butyl acrylate, isobutyl acrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate, and mixtures thereof.

[0198]

[0197] More advantageously, the (meth)acrylic monomer (M1) is selected from methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, methacrylic acid, acrylic acid, n-butyl acrylate, isobutyl acrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, and mixtures thereof.

[0199] According to one preferred embodiment, at least 50% by weight, preferably at least 60% by weight, of the (meth)acrylic monomers (M1) is methyl methacrylate.

[0200]

[0199] According to a first preferred embodiment, at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, advantageously at least 80% by weight and even more advantageously at least 90% by weight of monomer (M1) is a mixture of methyl methacrylate and, optionally, at least one other monomer.

[0201]

[0200] As for the (meth)acrylic monomer (M2), the monomer is polyfunctional. Preferably, the (meth)acrylic monomer (M2) is selected from compounds containing at least two (meth)acrylic functional groups. The (meth)acrylic monomer (M2) can also be selected from a mixture of at least two compounds (M2a) and (M2b), each of which contains at least two (meth)acrylic functional groups.

[0202]

[0201] (Meth)acrylic monomer (M2) is 1,3-butylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol dimethacrylate, dipropylene glycol diacrylate, ethoxylated (10) bisphenol A diacrylate, ethoxylated (2) bisphenol A dimethacrylate, ethoxylated (3) bisphenol A di ... Phenol A Dimethacrylate, Ethoxylated (4) Bisphenol A Diacrylate, Ethoxylated (4) Bisphenol A Dimethacrylate, Ethoxylated Bisphenol A Dimethacrylate, Ethoxylated (10) Bisphenol Dimethacrylate, Ethylene Glycol Dimethacrylate, Polyethylene Glycol (200) Diacrylate, Polyethylene Glycol (400) Diacrylate, Polyethylene Glycol (400) Dimethacrylate, Polyethylene Glycol (400) Dimethacrylate, Poly Ethylene glycol (600) diacrylate, polyethylene glycol (600) dimethacrylate, polyethylene glycol 400 diacrylate, propoxylated (2) neopentyl glycol diacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tripropylene glycol diacrylate, ethoxylated (15) trimethylolpropane triacrylate, ethoxylated (3) trimethylolpropane triacrylate, ethoxylated (6) trimethylolpropane triacrylate, ethoxylated (9) trimethylolpropane triacrylate, ethoxylated 5 pentaerythritol triacrylate, ethoxylated (20) trimethylolpropane triacrylate, propoxylated (3) glyceryl triacrylate, trimethylolpropane triacrylate, propoxylated (5.5) Glyceryl triacrylate, pentaerythritol triacrylate, propoxylated (3) Glyceryl triacrylate, propoxylated (3) Trimethylolpropane triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, di-trimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, ethoxylated (4) Pentaerythritol tetraacrylate, Pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 1,10-decanediol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,9-nonanediol diacrylate, 2-(2-vinyloxyethoxy)ethyl acrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, 2-methyl-1,3-propanediol diacrylate, 2-methyl-1,3-propanediyl ethoxy acrylate, 3-methyl- The alkoxylated hexanediol diacrylate may be selected from 1,5-pentanediol diacrylate, alkoxylated cyclohexane dimethanol diacrylate, alkoxylated hexanediol diacrylate, cyclohexane dimethanol diacrylate, ethoxylated cyclohexane dimethanol diacrylate, diethylene glycol diacrylate, dioxane glycol diacrylate, ethoxylated dipentaerythritol hexaacrylate, ethoxylated glycerol triacrylate, ethoxylated neopentyl glycol diacrylate, hydroxypivalyl hydroxypivalate diacrylate, neopentyl glycol diacrylate, poly(tetramethylene glycol) diacrylate, polypropylene glycol 400 diacrylate, polypropylene glycol 700 diacrylate, propoxylated (6) ethoxylated bisphenol A diacrylate, propoxylated ethylene glycol diacrylate, propoxylated (5) pentaerythritol tetraacrylate, and propoxylated trimethylolpropane triacrylate.

[0203]

[0202] Preferably, the (meth)acrylic monomer (M2) is selected from ethylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, triethylene glycol dimethacrylate and triethylene glycol diacrylate, or mixtures thereof.

[0204]

[0203] The (meth)acrylic monomer (M2) may be present in the (meth)acrylic composition MCI in an amount between 0.01 and 10 phr by weight, preferably between 0.1 and 9.5 phr, more preferably between 0.1 and 9 phr, even more preferably between 0.1 and 8.5 phr, and advantageously between 0.1 and 8 phr, relative to 100 parts of liquid (meth)acrylic syrup.

[0205]

[0204] In a first more preferred embodiment, the (meth)acrylic monomer (M2) is present in the (meth)acrylic composition MCI at between 0.01 and 9 phr and is chosen from compounds containing two (meth)acrylic functional groups.

[0206]

[0205] In a second more preferred embodiment, the (meth)acrylic monomer (M2) is present in the (meth)acrylic composition MCI at between 0.01 and 9 phr and is selected from a mixture of compounds containing two (meth)acrylic functional groups.

[0207]

[0206] In a third more preferred embodiment, the (meth)acrylic monomer (M2) is present in the (meth)acrylic composition MCI at between 0.01 and 9 phr and is selected from a mixture of compounds containing at least two (meth)acrylic functional groups.

[0208] In a fourth more preferred embodiment, the (meth)acrylic monomer (M2) is present in the (meth)acrylic composition MCI between 0.01 and 9 phr and is selected from a mixture of compounds containing at least two (meth)acrylic functional groups. At least one compound of the mixture contains only two (meth)acrylic functional groups and comprises at least 50% by weight of the mixture, preferably at least 60% by weight of (meth)acrylic monomer (M2). The other compounds of the mixture contain three or more (meth)acrylic functional groups.

[0209]

[0208] The initiator (Ini) for initiating the polymerization of the (meth)acrylic monomers (M1) and (M2) is selected from radical initiators.

[0210]

[0209] Preferably, the initiator (Ini) is activated by heat.

[0211]

[0210] The radical initiator (Ini) can be selected from peroxy group-containing compounds or azo group-containing compounds, preferably from peroxy group-containing compounds.

[0212]

[0211] Preferably, the peroxy group-containing compound contains 2 to 30 carbon atoms.

[0213]

[0212] Preferably, the peroxy group-containing compound is selected from diacyl peroxides, peroxy esters, peroxy dicarbonates, dialkyl peroxides, peroxy acetals, hydroperoxides or peroxy ketals.

[0214]

[0213] The initiator (Ini) is, for example, diisobutyryl peroxide, cumyl peroxyneodecanoate, di(3-methoxybutyl)peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, cumyl peroxyneoheptanoate, di-n-propyl peroxydicarbonate, tert-amyl peroxyneodecanoate, di-sec-butyl peroxydicarbonate, diisopropyl peroxydicarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, di-(2-ethylhexyl)peroxydicarbonate, peroxydicarbonate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, di-n-butyl peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxypivalate, tert-butyl peroxyneoheptanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, di-(3,5,5-trimethylhexanoyl)-peroxide, dilauroyl peroxide, dide peroxyethylhexanoyl, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)-hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, tert-amylperoxy-2-ethylhexanoate, dibenzoylperoxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxydiethylacetate, tert-butylperoxyisobutyrate, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-amyl peroxy)cyclohexane, 1,1-di-(tert-butylperoxy)-cyclohexane, tert-amylperoxy-2-ethylhexyl carbonate, tert-amylperoxyacetate, tert-butylperoxy-3,5,5-trimethylhexanoate, 2,2-di-(tert-butylperoxy)-butane, tert-butylperoxyisopropyl carbonate, tert-butylperoxy-2-ethylhexyl carbonate, tert-amylperoxybenzoate, tert-butylperoxyacetic acid, butyl 4,4-Di(tert-butylperoxy)valerate, tert-butylperoxybenzoate, di-tert-amyl peroxide, dicumyl peroxide, di-(2-tert-butylperoxyisopropyl)-benzene, 2,5-dimethyl-2,5-di-(tert-butylperoxy)-hexane, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, di-t ert-butyl peroxide, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azodi-(2-methylbutyronitrile), azobisisobutyramide, 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azodi(hexahydrobenzonitrile), or 4,4'-azobis(4-cyanopentanoic acid).

[0215]

[0214] Preferably, the initiator (Ini) is cumyl peroxyneodecanoate, di(3-methoxybutyl)peroxydicarbonate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, cumyl peroxyneoheptanoate, di-n-propylperoxydicarbonate, tert-amylperoxyneodecanoate, di-sec-butylperoxydicarbonate, diisopropylperoxydicarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, di-(2-ethylhexyl)-peroxydicarbonate, tert-amylperoxyneodecanoate, tert-butylperoxydicarbonate. peroxydicarbonate, di-n-butyl peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxypivalate, tert-butyl peroxyneoheptanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, di-(3,5,5-trimethylhexanoyl)-peroxide, dilauroyl peroxide, didecanoyl peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)-hexane or 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate.

[0216]

[0215] With regard to fibrous substrates, they include a plurality of fibers, unidirectional rovings or continuous filament mats, woven fabrics, felts or nonwoven fabrics, which may be in the form of strips, wraps, braids, locks or pieces. Fibrous materials have a variety of forms and dimensions, either one-dimensional, two-dimensional or three-dimensional. Fibrous substrates include an assembly of one or more fibers. When the fibers are continuous, these assemblies form a fabric.

[0217] The one-dimensional morphology corresponds to linear long fibers. The fibers may be discontinuous or continuous. They may be arranged randomly or parallel to one another in the form of continuous filaments. A fiber is defined by its aspect ratio, which is the ratio of the length of the fiber to its diameter. The fibers used in the present invention are long or continuous fibers. They have an aspect ratio of at least 1000, preferably at least 1500, more preferably at least 2000, advantageously at least 3000, and even more advantageously at least 5000, still more advantageously at least 6000, still more advantageously at least 7500, and most advantageously at least 10000.

[0218]

[0217] A two-dimensional form corresponds to a nonwoven or woven fibrous mat, which may be braided, or to reinforcing or bundled fibres. Even if a two-dimensional form has a certain thickness and is consequently three-dimensional in principle, it is considered according to the invention as being two-dimensional.

[0219]

[0218] The three-dimensional features may correspond, for example, to nonwoven mats, reinforcements, bundles of stacked or folded fibers, or mixtures thereof, where a collection of two-dimensional features is generated in the third dimension.

[0220]

[0219] The fibrous materials may be of natural or synthetic origin. Natural materials may include vegetable, wood, animal or mineral fibres.

[0221]

[0220] For example, natural fibers are sisal, jute, hemp, flax, cotton, coconut fibers, and banana fibers. For example, animal fibers are wool or hair.

[0222]

[0221] The synthetic material may include fibers of a polymer selected from the group consisting of fibers of a thermosetting polymer, fibers of a thermoplastic polymer, or mixtures thereof.

[0223]

[0222] The polymeric fibers can be comprised of polyamides (aliphatic or aromatic), polyesters, polyvinyl alcohol, polyolefins, polyurethanes, polyvinyl chloride, polyethylene, unsaturated polyesters, epoxy resins, and vinyl esters.

[0224]

[0223] The mineral fibres may also be chosen from glass fibres, carbon fibres, boron fibres or silicon fibres, in particular of type E, R or S2.

[0225]

[0224] The fibrous substrate of the present invention is selected from vegetable fibers, wood fibers, animal fibers, mineral fibers, synthetic polymer fibers, glass fibers, carbon fibers, and mixtures thereof.

[0226]

[0225] Preferably, the fibrous substrate is selected from mineral fibers, more preferably from glass fibers or carbon fibers.

[0227]

[0226] The diameter of the fibers of the fibrous substrate is between 0.005 μm and 100 μm, preferably between 1 μm and 50 μm, more preferably between 5 μm and 30 μm, advantageously between 10 μm and 25 μm.

[0228]

[0227] Preferably, the fibers of the fibrous substrate of the present invention are selected from continuous fibers for a one-dimensional morphology (meaning that the aspect ratio does not necessarily apply for long fibers) or long or continuous fibers for a two- or three-dimensional morphology of the fibrous substrate.

[0229] The present invention further relates to a method for producing a polymer composite PCI from a (meth)acrylic composition MCI, said method comprising the steps of: i) a fiber or fibrous substrate, a) a liquid (meth)acrylic syrup, a1) between 10% and 50% by weight of a (meth)acrylic polymer (PI), and a2) Between 50% and 90% by weight of (meth)acrylic monomers (M1) containing only one (meth)acrylic functional group 100 parts of liquid (meth)acrylic syrup containing b) between 0.01 and 10 phr by weight of a (meth)acrylic monomer (M2) containing at least two (meth)acrylic functional groups, and c) between 0.1 and 5 phr of an initiator (Ini) for initiating the polymerization of the (meth)acrylic monomer (M1) and the (meth)acrylic comonomer (M2); impregnating the substrate with a (meth)acrylic composition MCI comprising: ii) polymerizing the (meth)acrylic composition MCI impregnated into the fiber or fibrous substrate; Includes.

[0230]

[0229] Components a) to c) in the method for producing the polymer composite are the same as defined above, and the weight ratios of each are also the same.

[0231]

[0230] The polymerization step is typically carried out at a temperature of less than 140°C, preferably less than 130°C, and more preferably less than 125°C.

[0232]

[0231] Preferably, the polymerization step is carried out at a temperature between 40°C and 140°C, preferably between 50°C and 130°C, more preferably between 60°C and 125°C.

[0233]

[0232] The polymer composite PCI is preferably a (meth)acrylic polymer composite.

[0234]

[0233] The polymer composite PCI is preferably a fiber reinforced polymer composite.

[0235]

[0234] According to another aspect, the present invention relates to a folded thermoplastic composite.

[0236]

[0235] The folded thermoplastic composite is preferably obtained from a thermoplastic composite having a polymer matrix containing (meth)acrylic polymer of 35% or less by volume and a fiber of at least 65% by volume, or from a thermoplastic composite having a polymer matrix containing (meth)acrylic polymer of 20% to 30% by volume and a fiber of 70% to 80% by volume.

[0237]

[0236] Preferably, the folded thermoplastic composite is obtainable from the method of the present invention, and more preferably, the folded thermoplastic composite is obtainable from the method of the present invention.

[0238]

[0237] The folded thermoplastic composite can include several shapes. The folded portion can be a curvature, a twisted portion, a folded portion, a compressed portion. Preferably, the folded portion is a twisted portion. According to a preferred embodiment, the thermoplastic composite includes a change in its morphology in at least a portion of the entire thermoplastic composite.

[0239]

[0238] The folded thermoplastic composite is preferably a reinforcing element for reinforcing a structure. The reinforcing element can be, for example, a panel, a rod, a bar, a rebar, a sheet, etc. According to one embodiment, the thermoplastic composite may be composed of a number of sheets. Preferably, the thermoplastic composite is a rebar.

[0240]

[0239] The folded thermoplastic composite may have a variety of shapes, such as conical, pyramidal, elliptical, flat, linear, circular, etc.

[0241]

[0240] Thermoplastic composites may have a variety of dimensions (thickness, diameter, length, width, height).

[0242]

[0241] The thermoplastic composite may have a thickness of at least 2 mm, preferably at least 3 mm, more preferably at least 4 mm, even more preferably at least 5 mm. The thermoplastic composite may have a thickness of preferably not more than 35 mm, preferably not more than 30 mm, more preferably not more than 25 mm. Preferably, the thermoplastic composite may have a thickness between 2 mm and 35 mm, preferably between 3 mm and 30 mm, more preferably between 4 mm and 25 mm.

[0243]

[0242] The thermoplastic composite may have an outer diameter of at least 5 mm, preferably at least 6 mm, more preferably at least 10 mm, and even more preferably at least 13 mm. The thermoplastic composite may have an outer diameter of 40 mm or less, preferably 35 mm or less, more preferably 30 mm or less, and even more preferably 25 mm or less. The thermoplastic composite may have an outer diameter between 5 mm and 40 mm, preferably between 6 mm and 35 mm, more preferably between 10 mm and 30 mm, and even more preferably between 13 mm and 25 mm.

[0244]

[0243] Preferably, the thermoplastic composite is not limited by length.

[0245] Advantageously, the bent thermoplastic composite of the present invention meets all of the requirements of the Standard Test Method for Strength of Fiber Reinforced Polymer (FRP) Bent Bars in Bend Locations (ASTM D7914).

[0246]

[0245] Advantageously, the folded thermoplastic composite according to the present invention meets all the requirements of the standard Specification for Solid Round Glass Fiber Reinforced Polymer Bars for Concrete Reinforcement (ASTM7957).

[0247]

[0246] Advantageously, the folded thermoplastic composite of the present invention meets all of the requirements of the Standard Test Method for Measuring the Curved Beam Strength of a Fiber-Reinforced Polymer-Matrix Composite (ASTM D6415).

[0248]

[0247] The folded thermoplastic composite material of the present invention is particularly suitable for structural reinforcement.

[0249]

[0248] In another aspect, the present invention relates to the use of the folded thermoplastic composite material according to the present invention in automotive, transportation, marine, rail, sports, aviation, aerospace, solar power, construction and building, and / or wind energy applications.

[0250]

[0249] According to another aspect of the invention, preferably in accordance with the invention, there is provided a system 10 for producing folded thermoplastic composites from thermoplastic composites comprising a polymer matrix of up to 35% by volume of (meth)acrylic polymer and at least 65% by volume of fibers. An example of the system is shown in Figure 4.

[0251]

[0250] Advantageously, the system is suitable for carrying out the method according to the invention.

[0252]

[0251] The system of the present invention includes a heating device, a bending device, and a cooling device.

[0253]

[0252] The heating device 11 may be configured to heat a part of the thermoplastic composite. By means of the heating device one or more parts of the thermoplastic composite may be locally heated and softened for final folding. Advantageously, the heating device may be configured to heat the part directly or indirectly, i.e. by direct contact or not, for example by heat transfer. Per part is to be understood as one or more parts of the thermoplastic composite and one or more surfaces of the part of the thermoplastic composite.

[0254]

[0253] The heating device can be selected from among conductive heating, radiative heating, and / or volumetric heating.

[0255] The heating device may comprise a mould, an enclosure, a microwave source, an infrared source (NIR / MIR), a blower and / or an induction source. Preferably, the heating device comprises an infrared heating device or a microwave heating device. This ensures that the part to be heated is heated sufficiently uniformly up to the core of the thermoplastic composite in a relatively short time, without increasing the surface temperature of the thermoplastic composite too much, which would cause the thermoplastic material to turn into a flowable state or cause surface degradation or property changes.

[0256]

[0255] Advantageously, the heating device is programmable to determine the heating temperature, the temperature reached (core and / or surface) and / or the heating time.

[0257]

[0256] Advantageously, the heating device may be equipped with one or more IR or thermometer type heating sensors for controlling different heating temperatures and / or a timer for controlling the heating time.

[0258]

[0257] Advantageously, the device may also include an alarm configured to warn when a temperature or duration is exceeded or to warn when a temperature or duration is reached.

[0259]

[0258] Preferably, the heating device is located upstream of the folding device.

[0260]

[0259] According to one embodiment, the heating device is digitally / automatically controlled and / or moved or manually controlled and / or moved to the heating position and removed. Advantageously, the heating device may be removable.

[0261]

[0260] The system according to the invention may include a folding device 12. The folding device is configured to create folded sections in the heated portion by creating folded portions in the heated portion.

[0262]

[0261] The folding device may include means for twisting, bending, curving, and / or folding.

[0263]

[0262] For example, the bending device may include a bending region with a bending arm rotatable around the bending region and having a clamp for clamping the heated portion, the bending arm and the bending region each being rotatable about a predetermined bending axis.

[0264]

[0263] The bending device may include clamping jaws for clamping and bending the heated portion.

[0265]

[0264] The folding device may be movable.

[0266]

[0265] Alternatively, the heating part may be rotatable, for example, by a roller, a reel, motorized or not. The rotation angle as well as the rotation speed can be preset. Depending on the magnitude of the twist, the folding device may carry out a controlled compensating movement in the longitudinal direction of the heating part.

[0267]

[0266] According to another embodiment, the folding device may comprise, for example, one or more folding rollers, opposing belts, opposing folding surfaces, opposing belts, or opposing folding surfaces that bend the locally heated portion to achieve the final bend.

[0268]

[0267] The system according to the present invention may also include a cooling device 13.

[0269]

[0268] The cooling device is configured to solidify the folded sections to form a folded thermoplastic composite.

[0270]

[0269] Preferably, the cooling device is adapted so that the heated portion becomes solid again, whereby the heated portion becomes solid again and can be removed from the folded configuration without deformation.

[0271]

[0270] Advantageously, the cooling device may be configured to cool the folded portion directly or indirectly, i.e. by direct contact or without contact. Per folded portion is to be understood as one or more folded portions of the thermoplastic composite and one or more surfaces of the folded portion of the thermoplastic composite.

[0272]

[0271] The cooling device may comprise cooling the folded portion to a cooling temperature at which the folded portion changes to a thermoplastic or solid state. Preferably, the cooling temperature is below the glass transition temperature of the thermoplastic composite, for example 120°C or less, preferably 110°C or less.

[0273]

[0272] A cooling device is also provided to rapidly cool the folded sections, preferably in 390 seconds or less.

[0274]

[0273] Advantageously, cooling may be instantaneous or alternatively slow.

[0275]

[0274] For this purpose, the folding device may be equipped with a cooling device for actively cooling the folded portion, which may include compressed air.

[0276]

[0275] Alternatively, the cooling system may include passive or automatic cooling, which may be the mold, the nozzle, the coolant circuit, the coolant flow, and / or a fan.

[0277]

[0276] According to one embodiment, the cooling device may be integrated directly into the folding device.

[0278]

[0277] This system may be arranged along with a pultrusion apparatus, which includes all the necessary equipment for pultrusion, such as a feeder, a resin tank, an impregnation device, a lifting device, and an ejection device.

[0279]

[0278] Advantageously, the system may include an IHM or automation module for setting the parameters of the system and for monitoring, controlling and managing all devices of the system such as temperature, duration etc.

[0280]

[0279] The present invention is capable of numerous modifications and applications other than those described above. Unless otherwise specified, the different structural and functional characteristics of each of the above implementations should not be considered as combined with each other and / or intimately and / or inseparably linked, but rather as simple juxtapositions. Moreover, the structural and / or functional characteristics of the different embodiments described above may be subject to any different juxtapositions or any different combinations, in whole or in part.

Claims

1. A method (100) for producing a folded thermoplastic composite from a thermoplastic composite, the thermoplastic composite comprising a polymer matrix comprising 35% by volume or less of a (meth)acrylic polymer and at least 65% by volume of fibers, the method comprising: - providing a thermoplastic composite (110), preferably by pultrusion; - heating (120) a portion of the thermoplastic composite, said heating being selected from conductive, radiative and / or volumetric heating, the heating time and / or heating temperature being selected depending on at least the thickness of the thermoplastic composite; - creating folded sections in the heated part by folding the heated part (130); cooling (140) the folded sections at a cooling temperature and / or cooling time selected depending on the glass transition temperature (Tg) of the folded thermoplastic composite to solidify and form a folded thermoplastic composite; A method (100) comprising:

2. 2. The method (100) of claim 1, wherein the heating step (120) is radiant heating, preferably IR heating.

3. 2. The method (100) according to claim 1, characterized in that the heating time is less than or equal to 95 seconds, preferably less than or equal to 60 seconds, and preferably the inner temperature of the thermoplastic composite is less than or equal to 180°C.

4. 2. The method (100) of claim 1, characterized in that between the heating step (120) and the cooling step (140), the temperature difference between the inner temperature and the outer temperature of the thermoplastic composite is between 0°C and 50°C.

5. 2. The method (100) according to claim 1, characterized in that the temperature difference between the inner and outer temperatures of the thermoplastic composite during the heating step is not more than 80°C, preferably for heating for not more than 95 seconds.

6. 2. The method (100) of claim 1, characterized in that the thermoplastic composite is obtained from a pultrusion process, preferably a reactive pultrusion process.

7. 10. The method (100) of claim 1, wherein the thermoplastic composite is crosslinked, partially crosslinked, or non-crosslinked.

8. 10. The method (100) of claim 1, wherein the outer temperature of the heated portion of the thermoplastic composite is between 140°C and 230°C and the heating time is 95 seconds or less.

9. The method (100) of claim 1, characterized in that the outer temperature of the heated part of the thermoplastic composite is between 200°C and 250°C and the heating time is less than or equal to 95 seconds.

10. 2. The method (100) of claim 1, wherein the step (130) of creating the folded portion is performed by simple bending, compressive bending, folding and / or twisting.

11. 10. The method (100) of claim 1, wherein the thermoplastic composite is a (meth)acrylic thermoplastic composite.

12. A folded thermoplastic composite obtained from a thermoplastic composite, the folded thermoplastic composite comprising a polymer matrix comprising 35% by volume or less of a (meth)acrylic polymer, and at least 65% by volume of fibers.

13. 13. Use of the folded thermoplastic composite of claim 12 in automotive, transportation, marine, rail, sports, aviation, aerospace, solar power, construction and building, and / or wind energy applications.

14. 1. A system (10) for producing a folded thermoplastic composite from a thermoplastic composite, the thermoplastic composite comprising a polymer matrix comprising 35% or less by volume of a (meth)acrylic polymer and at least 65% by volume of fibers, the system comprising: a heating device (11) configured to heat a portion of the thermoplastic composite, said heating device (11) being selected from conductive, radiative and / or volumetric heating, the heating time and / or heating temperature being selected depending at least on the thickness of the thermoplastic composite; a folding device (12) configured to create folded sections in the heated portion by folding the heated portion; a cooling device (13) configured to solidify the folded sections to form a folded thermoplastic composite at a cooling temperature and / or for a cooling time selected depending on the glass transition temperature of the thermoplastic composite; A system (10) comprising:

15. 15. The system of claim 14, wherein the heating device comprises a mold, an enclosure, a microwave source, an IR source (NIR / MIR), a blower and / or an induction source.

16. 15. The system of claim 14, wherein the heating device comprises an infrared heating device or a microwave heating device.

17. 15. The system of claim 14, wherein the system is disposed in line with a pultrusion device.

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