temperature profile determination

Abstract

A method for determining the temperature to which a length of material is heated during a heating step in a continuous process is provided, comprising the steps of measuring the temperature of the material at two or more distances along the length of the material after the heating step; and calculating the temperature of the material at the heating step based on the temperature at the one or more distances along the length of the material. Further provided is a method of monitoring the temperature to which a molded material is heated in an impregnation step in a continuous manufacturing process, comprising the steps of combining a fibrous reinforcement layer and a thermoplastic or thermoset resin layer, and at least partially impregnating the resin into the fibrous reinforcement layer in an impregnation step to form an at least partially impregnated molded material; measuring the temperature of the at least partially impregnated molded material at one or more distances along the length of the molded material after passing through the impregnation step; and calculating the temperature to which the molded material is heated in the impregnation step based on the temperature at the one or more distances along the length of the molded material.

Description

Technical Field

[0001] This invention relates to a method for determining the temperature of a material during heating in a continuous process, and more particularly to a method for determining the temperature of a mesh product, such as a pre-impregnated composite material, during production. Background Technology

[0002] Composite materials composed of reinforcing fibers combined with a resin matrix are widely used in a variety of applications due to their advantageous properties such as high strength, light weight, and the ability to be molded at relatively low temperatures.

[0003] Such composite materials are typically manufactured by impregnating a resin into a reinforcing structure. The reinforcing structure is typically unidirectionally arranged fibers, woven fiber mats, or, in limited cases, randomly oriented chopped fiber webs.

[0004] Once the fiber reinforcement has been impregnated with resin, the resulting prepreg composite (often referred to as "prepreg") is often stored as an intermediate product, with the resin in an uncured state, allowing the prepreg to remain malleable. This allows the prepreg to be transported to a final manufacturing facility where it can be molded into the desired final shape before the resin is cured.

[0005] Uncured resins tend to have relatively high viscosity. To ensure that the resin adequately impregnates the fiber reinforcement during application (i.e., flows into the fiber web to fill the internal spaces and coat the internal fibers in addition to the surface fibers), the resin is typically heated to reduce its viscosity and thus increase its ability to flow into the fiber reinforcement (i.e., impregnate the fibers). Pressure is also typically applied to the fibers and resin at the "nip point," for example, by pressing the resin and fibers together using one or more rollers.

[0006] Many resins used in the manufacture of prepregs are thermosetting resins (i.e., resins that are heated to a temperature above a certain level for a sufficiently long period of time to cure). Even when heated for a shorter time or to a lower temperature than required for complete curing, the resin itself and its components (such as additional reactive and non-reactive additives, such as curing agents, hardeners, toughening agents, accelerators, and flame retardants) may react with heat and undergo chemical or physical changes. A particular resin composition can be assigned a "time to maximum rate" (TMR) value, which indicates the total amount of time the resin can remain at elevated temperatures before excessive chemical and / or physical changes occur in the resin, such that the final composite product (e.g., prepreg) no longer meets a desired quality threshold.

[0007] To ensure that the TMR (Total Molecular Weight) is not exceeded and the final product meets the required quality thresholds, it is essential to accurately understand the thermal conditions the resin is exposed to during the impregnation step. Exceeding the resin's TMR can negatively impact its quality, and consequently, the strength, moldability, and lifespan of the composite product. The thermal conditions of the resin during impregnation can also affect the degree of impregnation; if the temperature is too low or too high, the resin impregnation may be insufficient. This, in turn, affects the quality of the final product.

[0008] However, it is usually inconvenient to directly monitor the temperature of the resin at the point where it is applied to the fiber / impregnated fiber (i.e., the "roll gap point") because temperature probes or IR sensors are not accessible at this point (the roller, process paper, and fiber web themselves all obstruct access to or view of the roll gap point).

[0009] Therefore, existing processes and systems typically monitor the temperature of one or more rolls or the temperature of the resin feed itself (i.e., before it reaches the roll gap). However, these rolls and the resin feed typically have a much higher thermal mass than the resin / fiber system at the roll gap, and are therefore insensitive to fluctuations in the heat flow into the product. Furthermore, roll temperature measurements are insensitive to any changes or fluctuations in linear speed, roll pressure, or linear tension. Therefore, without careful calibration and frequent recalibration (which results in significant system downtime), neither of these measurement techniques can reliably provide an accurate value for the actual process temperature at the roll gap. Summary of the Invention

[0010] Therefore, the present invention seeks to provide a method for more accurately determining the temperature of a material at a process point when it is not feasible to directly measure the temperature at the process point.

[0011] From a first aspect, the present invention provides a method for determining the temperature to which a material of a certain length is heated during a heating step in a continuous process, comprising the steps of: measuring the temperature of the material at two or more distances along the length of the material after the heating step; and calculating the temperature of the material at the heating step based on the temperature at the one or more distances along the length of the material.

[0012] By measuring the material temperature at one or more distances along its length after the heating step, the temperature at the heating step / process point can be calculated / inferred. Therefore, a more accurate and complete material temperature history can be determined.

[0013] The step of calculating the material temperature at the heating step may consider one or more of the following: the distance between the heating step and the temperature measurement point; the thickness of the material; the heat transfer coefficient; the ambient air temperature; the ambient air pressure; the humidity; the air velocity around the material / the material's transport velocity; the thermal diffusivity of the material (i.e., internal thermal conduction within the material); and radiant heat from nearby process components or other components.

[0014] Temperature calculations at the heating step can be based on an empirically derived model, which is based on initial calibration data to fit the curves to experimental data.

[0015] The temperature at the heating step can be calculated based on Newton's law of cooling. Newton's law of cooling predicts the temperature (T) after a time interval (t) according to the following formula:

[0016] T = T a + (T h – T a )e kt

[0017] Where T a It refers to the ambient temperature; T h is the initial temperature (i.e., the temperature at the heating step to be determined), and k is the heat transfer coefficient. Therefore, by measuring the ambient temperature (T... a The material temperature (T) at a known time (t) after the heating step (or at a known distance from the heating step when the transfer speed is known) can be determined, and the temperature at the heating step can be determined when the heat transfer coefficient (k) is known.

[0018] The calculation of the temperature at the heating step can include taking into account the thermal conductivity of the material along its length. The thermal conductivity along the material length can be modeled using the forward Eulerian method.

[0019] Alternatively (or additionally), the calculation of the temperature at the heating step may include the following steps: reproducing the physical system in a finite element or hydrodynamic simulation or other numerical tool. In such a simulation, the material block is assigned material properties (heat capacity, conductivity, etc.). Heat transfer and other properties from the material and other system components (e.g., rollers) can then be calculated by applying small time steps to converge to an equilibrium solution to predict the temperature of the material at various (measurable) locations. The actual temperatures at these locations can then be measured, compared with the simulation, and the simulation can be calibrated to determine the predicted temperature at the heating step. While running the simulation in real time is generally impractical (due to the required processing power), the simulation results (along with actual temperature measurements) can be fed into machine learning algorithms (e.g., convolutional neural network algorithms, k-nearest neighbor algorithms, decision tree models). By feeding the results into machine learning algorithms, the accuracy of the model can be improved to a level comparable to finite element / hydrodynamic simulations, for future measurements while allowing real-time modeling.

[0020] The material may be a resin or contain a resin, such as a thermosetting resin. When the material is or contains a resin or a thermosetting resin, the method advantageously allows for a more accurate determination of the resin's temperature history to determine whether the resin has exceeded or is approaching its TMR. When the material contains a thermosetting resin, the resin is preferably in an uncured state (i.e., not yet exceeding its TMR).

[0021] The material may be a composite material (i.e., the material may consist of two or more separate material components). The composite material may include a reinforcing material (such as a fiber material) and a matrix (such as a resin or a thermosetting resin).

[0022] The material may include resin and process films, such as plastic or paper-backed sheets.

[0023] The heating step may include bringing the material into contact with a heated surface, into contact with a heated material, or heating indirectly.

[0024] For example, the heating step may include bringing the material into contact with one or more heated rollers to transfer heat directly to the material by conduction.

[0025] The one (or more) heated rollers may form part of a compaction roller system, and the continuous process may include a compaction roller step. The compaction roller system may be a pinch roller system (or a gap roller system) through which the material passes in the continuous process. Alternatively, the one (or more) heated rollers may form part of an "S-shaped winding" roller system, wherein the material is wound around the roller with a greater circumferential extent than the pinch rollers / clamping rollers, and thus maintains contact with the roller for a longer period to improve heat exchange.

[0026] Continuous processes may include the following steps: combining two or more individual material components together, for example, forming a composite material at a pinch roll system. When the material is a composite of two or more material components, the method can be used to determine the temperature to which the composite material is heated during a heating step, or to heat one or more individual material components of the composite material during a heating step.

[0027] In continuous processes that include the step of combining two or more individual material components, the first component may be a resin, such as a thermosetting resin. The second component may be a reinforcing material, such as a fiber-reinforced material. The resulting combined material may be a composite material. Alternatively, the second component may be a paper or plastic film or sheet.

[0028] For pinch roll pressing systems and S-shaped winding continuous systems, directly measuring the temperature to which the material is heated is often challenging because only the temperature of the roll itself can be measured, and the physical nature of the roll hinders access to other temperature probes or IR sensors. The thermal mass of the roll also makes accurate material measurement at the heating point difficult. By providing a method for determining the material temperature by measuring the material temperature after a heating step in a continuous process, the present invention advantageously eliminates the need for direct temperature measurement at the heating point.

[0029] Alternatively, where the heating step is indirect, it may include radiative heating of the material using, for example, an infrared heater / emitter. Other indirect heating methods that may be used include convection heating, induction heating (i.e., direct electromagnetic induction in conductive fibers such as carbon fibers), resistance heating (i.e., directly heating conductive fibers such as carbon fibers by allowing current to flow through the fibers), dielectric heating (i.e., applying an electric field to a dielectric material such as a resin), and microwave or RF heating.

[0030] The material may be in the form of a strip. In the context of this invention, the term "strip" should be interpreted as meaning that the material is elongated (i.e., its length is greater than its width), and preferably its length is at least 5 times its width, or more preferably at least 10 times its width, or even more preferably at least 50 times its width; and the thickness of the material is preferably less than 10% of its width, or more preferably less than 5% of its width, or even more preferably less than 1% of its width.

[0031] The step of measuring the temperature of the material preferably includes measuring the temperature of the material at two, more preferably three or more distances along the length of the material after the heating step; and the step of calculating the temperature of the material preferably includes calculating the temperature of the material at the heating step based on the temperature at the two, more preferably three or more distances along the length of the material.

[0032] By measuring the material's temperature at multiple distances along its length after the heating step, the temperature at that point can be determined more accurately. For example, when the temperature calculation is based on Newton's law of cooling, two or more data points improve accuracy by revealing any changes in the heat transfer coefficient (k) from a known value due to variations in the material or environment. The heat transfer coefficient (k) may differ from experimentally determined values ​​depending on environmental conditions (temperature, airflow, humidity), changes in the material's surface area, and the material's transport velocity. Therefore, two or more data points (preferably three or more) can incorporate these variables into temperature calculations with greater accuracy. When the heat transfer coefficient (k) is unknown, two or more data points (preferably three or more) can determine k by fitting an exponential curve to the data.

[0033] When measuring the temperature of a material at multiple distances along its length after a heating step, it is preferable to minimize the first distance (i.e., the first temperature measurement point is as close as possible to the heating step without affecting the accuracy of the temperature measurement, for example, due to radiation emission from the heated rollers). The actual first distance will depend on the accessibility of the heating site, the type of temperature probe or sensor used, and the size and radiation effects of surrounding components such as the rollers; however, for a given system, it can be readily determined through routine experiments.

[0034] When measuring material temperature at multiple distances along the length of the material after a heating step, it is preferable to maximize the final distance (i.e., the final temperature measurement point is as far away from the heating step as possible before the material undergoes further steps in a continuous process that may affect its temperature (e.g., further contact points, further direct or indirect heating, cooling by exposure to coolant, forced airflow, or contact with a heat exchanger, or the addition of further material components to the material). The actual final distance will depend on the system configuration, however, it can be easily determined.

[0035] When measuring the material temperature at three distances along the length of the material after the heating step, preferably, as described herein, the first distance is minimized, the last distance is maximized, and the temperature is also measured at an intermediate distance between the first and last distances.

[0036] The intermediate distance can be the average of the first distance and the last distance (mean distance) (i.e., the intermediate temperature measurement point can be located at the midpoint between the first temperature measurement point and the last temperature measurement point).

[0037] Alternatively (and preferably), the intermediate distance is such that the material temperature measured at the intermediate distance is approximately equal to the average temperature (mean temperature) measured at the first and last distances (i.e., making the temperature difference between adjacent sensors uniform). In this case, the first temperature measurement point, the intermediate temperature measurement point, and the last temperature measurement point are not equidistant: due to the exponential nature of material cooling, the intermediate point will be closer to the first point than the last point.

[0038] When measuring the material temperature at more than three distances along the length of the material after the heating step, preferably, as described herein, the first distance is minimized, the last distance is maximized, and the temperature is also measured at a series of intermediate distances between the first and last distances.

[0039] The intermediate distances in the series can be equally spaced between the first distance and the last distance. Alternatively (and preferably), a series of intermediate distances can be spaced such that the temperature measured at each intermediate distance is approximately equal to the average temperature (mean temperature) measured at two adjacent distances (i.e., adjacent first distance and intermediate distance; two adjacent intermediate distances; or adjacent intermediate distance and last distance).

[0040] The continuous process may include a further heating step, and the method may further include the following steps: determining the temperature to which the material was heated during the further heating step by measuring the material temperature at one or more distances along the length of the material after the further heating step; and calculating the temperature of the material at the further heating step based on the temperature at one or more distances along the length of the material after the further heating step.

[0041] The step of calculating the material temperature at the further heating step can be based on any formula defined herein for determining the material temperature at the heating step. The step of calculating the material temperature at the further heating step can be based on the same formula as the step of calculating the material temperature at the heating step, or a different formula.

[0042] The further heating step may be substantially the same as the heating step, or it may be a different method or use of a different system to heat the material. The further heating step may include any method or system used for the heating step as described herein.

[0043] One or more distances along the length of the material following a further heating step may include one or more of the following: a first distance minimized relative to the further heating step; a final distance maximized relative to the further heating step; and one or more intermediate distances, as discussed herein with reference to the heating step.

[0044] The continuous process can be a process of impregnating a reinforcing material layer with resin. Therefore, the length of the material can be the length of a composite material comprising the reinforcing material and the resin. Alternatively, the length of the material can be the resin itself dispersed / deposited on the reinforcing material.

[0045] The resin can be a thermoplastic resin or a thermosetting resin. The resin can be any resin commonly used in the manufacture of composite materials. For example, the resin can be a phenolic-based resin, an epoxy-based resin, a bismaleimide-based resin, or a polyimide-based resin. The resin may contain one or more reactive and non-reactive additives, such as curing agents, hardeners, toughening agents, accelerators, and flame retardants.

[0046] The reinforcing material may be a fibrous material comprising multiple filaments that extend unidirectionally or are woven into a tape. The fibrous material may be any fibrous material commonly used in the manufacture of composite materials, such as glass fiber, carbon fiber, polyethylene, or aramid.

[0047] Alternatively, the continuous process can be a process of forming a film from a polymer or thermosetting resin precursor, such as applying the polymer or resin to a backing sheet or backing paper, followed by transferring the resin or polymer from the backing sheet to fibers. In the film-forming process, accurate control of the resin / polymer thickness is important, and this depends on the viscosity of the resin / polymer. Therefore, accurately understanding / controlling the resin / polymer temperature in the film-forming process is crucial for maintaining consistency and quality.

[0048] The method may further include the following steps: monitoring the temperature to which the material is heated at the heating step (and / or, where applicable, a further heating step); and adjusting the process conditions if the temperature to which the material is heated drops below or above a specified value. Therefore, the method can be advantageously used to provide feedback to the heating step (and / or further heating step) of a continuous process to ensure that the continuous process has a consistent output (i.e., the temperature to which the material is heated remains consistent or at least within acceptable tolerances).

[0049] For example, the step of adjusting process conditions may include adjusting the temperature to which one or more heating rollers are heated to regulate the amount of heat energy transferred from the one or more heated rollers to the material. Alternatively, in the case where the material is a combination of two or more individual material components, or in the case where the material is a single component of a combination material, and wherein one / the single component is heated prior to the combination step, the temperature to which the single component is heated may be adjusted.

[0050] From a second aspect, the present invention provides a method for monitoring the temperature to which a molding material is heated during an impregnation step in a continuous manufacturing process, comprising the steps of: combining a fiber reinforcement layer and a thermoplastic or thermosetting resin layer, and impregnating the resin at least partially into the fiber reinforcement layer in the impregnation step to form at least partially impregnated molding material; measuring the temperature of the at least partially impregnated molding material at one or more distances along the length of the molding material after the impregnation step; and calculating the temperature to which the molding material was heated during the impregnation step based on the temperature at the one or more distances along the length of the molding material.

[0051] The step of calculating the temperature at the impregnation step can be based on Newton's law of cooling or any other calculation method as described herein.

[0052] The impregnation step may include contacting the fiber reinforcement layer and the thermoplastic or thermosetting resin layer with a heated surface and applying pressure. For example, the impregnation step may include passing the fiber reinforcement through an S-shaped winding system or a pinch / press system of heated rollers while applying resin to the reinforcement and applying pressure to the combined resin and reinforcing fibers to impregnate the fiber reinforcement with resin and form a molding material.

[0053] The molding material can be in the form of a strip.

[0054] The fiber reinforcement can be any fibrous material commonly used in the manufacture of composite materials, such as glass fiber, carbon fiber, polyethylene, or aromatic polyamide. The resin can be any resin commonly used in the manufacture of composite materials, such as phenolic resin, epoxy resin, bismaleimide resin, or polyimide resin. The resin may include one or more reactive and / or non-reactive additives, such as curing agents, hardeners, toughening agents, accelerators, or flame retardants.

[0055] The step of measuring the temperature of the at least partially impregnated molding material preferably includes measuring the temperature of the molding material at two or more (or more preferably three or more) distances along the length of the molding material after the impregnation step, and the step of calculating the temperature to which the molding material is heated preferably includes calculating the temperature of the molding material during the impregnation step based on the temperatures measured at the two or more (or more preferably three or more) distances along the length of the molding material.

[0056] When the temperature of the at least partially impregnated molding material is measured at multiple distances along the length of the at least partially impregnated molding material after the impregnation step, as described herein with reference to a first aspect of the invention, the first distance is preferably minimized; and / or the final distance is preferably maximized, as described herein with reference to a first aspect of the invention.

[0057] When measuring the temperature of the at least partially impregnated molding material at three or more distances along the length of the at least partially impregnated molding material after the impregnation step, one or more intermediate distances may be spaced as described herein with reference to the first aspect of the invention.

[0058] The continuous manufacturing process may include a heating step after the impregnation step, and the temperature to which the molding material is heated during the heating step can be determined by measuring the temperature of the molding material at one or more distances along the length of the molding material after the heating step; and the temperature to which the molding material is heated at the heating step can be calculated based on the temperature at the one or more distances along the length of the molding material.

[0059] The step of calculating the material temperature at the heating step can be based on any formula defined herein for determining the material temperature, referring to the first aspect of the invention. The step of calculating the material temperature at the heating step can be based on the same formula or a different formula as the step of calculating the material temperature in the impregnation step.

[0060] The heating step may include any method or system as described herein for the heating step of the first aspect.

[0061] One or more distances along the length of the material following the heating step may include one or more of the following: a first distance minimized relative to the heating step; a final distance maximized relative to the heating step; and one or more intermediate distances, as discussed herein with reference to the heating step in the first aspect.

[0062] The method may further include the following steps: monitoring the temperature to which the molding material is heated during the impregnation step (and / or, where applicable, the heating step); and adjusting the process conditions if the temperature to which the molding material is heated drops below or above a specified value. For example, adjusting the process conditions may include adjusting the temperature of one or more heated rollers. Alternatively or additionally, if the resin is preheated prior to the impregnation step, adjusting the process conditions may include adjusting the temperature to which the resin is preheated.

[0063] From a third perspective, the present invention provides a system for continuously processing materials, comprising: a heater configured to heat the material at a heating point; one or more temperature sensors configured to measure the temperature of the material at one or more points after the heating point; and a processor configured to receive temperature data from the one or more temperature sensors and determine the temperature of the material at the heating point based on a cooling model.

[0064] The cooling model can be Newton's law of cooling or any other calculation method as described herein.

[0065] The material may be in the form of a strip. The material may be a molding material comprising fiber reinforcement and a thermoplastic or thermosetting resin. The fiber reinforcement and thermoplastic or thermosetting resin may be as defined above with respect to the second aspect of the invention.

[0066] The heater can be configured to heat the material by bringing it into contact with a heated surface. For example, the heater may include one or more heated rollers configured to contact the material along its transport path. The one or more heated rollers may be part of a pinch roller / pinch roller system or an S-shaped winding system configured to combine multiple individual material components (such as fiber reinforcements and resins) into a composite material (such as a molding material).

[0067] The one or more temperature sensors may be infrared sensors positioned after the heating step, spaced apart from and pointing towards the material transport path to measure the temperature of the material at one or more points. Alternatively, the temperature sensors may be probes configured to contact the material at one or more points along the material transport path after the heating step to measure the temperature of the material at those points.

[0068] Alternatively, the one or more temperature sensors can be thermal imaging cameras. The thermal imaging camera can be configured to capture a single thermal image of the material covering multiple temperature measurement points. The temperature of the material can then be observed at each measurement point by reading the recorded temperature of sample pixels (or groups of pixels) in the image. This advantageously enables simultaneous measurement of the material temperature at multiple distances after a heating step, without requiring multiple separate sensors. By simply increasing the number of sample pixels / groups, the number of measurement points can be increased and decreased as needed, thus eliminating the need for additional hardware.

[0069] One or more temperature sensors may be fixed at a static position relative to the heating point to measure the material temperature at a fixed distance from the heating point. Alternatively, one or more temperature sensors may be configured to move substantially parallel to the material after the heating step to measure the material temperature at a fixed point on the material at one or more distances after the heating point or over a continuous range from the initial measurement point to the final measurement point.

[0070] A moving temperature sensor can be configured to move at a rate substantially the same as the material's rate of movement (i.e., linear velocity), allowing the sensor to effectively monitor the same physical location on the material as it moves. Alternatively, the moving temperature sensor can be configured to move faster than the linear velocity. This advantageously allows for a faster measurement frequency (i.e., a complete set of temperature measurements from the initial measurement point to the final measurement point can be completed in a shorter time due to the faster sensor movement).

[0071] In the presence of two or more fixed temperature sensors, preferably, the first fixed temperature sensor is configured to measure the material temperature at the minimum distance from the heating step. Preferably, the last fixed temperature sensor is configured to measure the material temperature at the maximum distance from the heating step.

[0072] In the case where a temperature sensor is configured to move at a rate substantially parallel to and the same as the material to measure the material temperature at one or more distances, preferably, the initial measurement point is located at the minimum distance from the heating step; and the final measurement point is located at the maximum distance from the heating step.

[0073] In a first aspect of the invention, the maximum distance and the minimum distance can be defined based on the maximum distance and the minimum distance. Attached Figure Description

[0074] Specific implementations of the invention will now be described by way of example only and with reference to the accompanying drawings, wherein:

[0075] Figure 1 This is a simplified diagram of a system for determining the material temperature at a heating point in a continuous process, according to one embodiment of the present invention.

[0076] Figure 2 This is a simplified diagram of a system for determining the material temperature at a heating point in a continuous process according to a second embodiment of the present invention.

[0077] Figure 3 This is a simplified diagram of a system for determining the material temperature at two heating points in a continuous process according to a third embodiment of the present invention.

[0078] Figure 4 It is a graph that shows the use of Figure 1 In an exemplary continuous process of the system and the method for determining the temperature at the heating step according to a specific embodiment of the present invention, the material temperature changes over time after the heating step.

[0079] Figure 5 shows three curve graphs, which illustrate... Figure 1 The change in linear velocity of the system ( Figure 5A ), material thermal diffusivity ( Figure 5B ) and heat transfer coefficient ( Figure 5C The effect of this on the material temperature at various distances after the heating step.

[0080] Figure 6 shows the actual roller temperature versus the temperature based on... Figure 4 The difference between the predicted roller temperatures calculated by the method shown ( Figure 6A ); and the first derivative of the actual roll temperature (the rate of change of the actual roll temperature) as a function of the predicted temperature error ( Figure 6B ).

[0081] Figure 7 is a graph that shows the spectrum relative to... Figure 1 The heating points in the system are defined by the "span" (the distance between the first and last sensors) and the positions of the first and last sensors as well as the midpoint of the sensor array. Figure 7A ) and the intermediate sensor position relative to the first sensor position and the last sensor position ( Figure 7B The impact on the accuracy of temperature prediction at the heating point.

[0082] Figure 8 shows four graphs illustrating the sensor spacing ( Figure 8A and Figure 8B ) and linear velocity ( Figure 8C and Figure 8D The impact of changes in ( ) on the accuracy of model predictions. Detailed Implementation

[0083] First refer to Figure 1A portion of a system 1 for performing a continuous process on a material is shown in a simplified form (not to scale). In this particular embodiment, the continuous process is a process for forming a molded material in the form of a preimpregnated composite material (prepreg) consisting of fiber reinforcement 10 and a matrix composed of resin 32, the matrix being impregnated into the fiber reinforcement such that the resin coats the filaments on the surface and inside of the fiber reinforcement 10.

[0084] Figure 1 A portion of system 1 is shown, configured for combining fiber reinforcement 10 with resin 32 to form molding material 12. System 1 includes an impregnation system 20, which includes a first heated roller 22 arranged adjacent to and with a small gap from a second heated roller 24. A roll gap point 23 is defined as the point between the first heated roller 22 and the second heated roller 24 where the gap between them is minimal.

[0085] The first roller 22 and the second roller 24 are configured to rotate in opposite directions. In this particular embodiment, the first heated roller 22 is configured to rotate clockwise, and the second heated roller 24 is configured to rotate counterclockwise. Thus, an article in contact with the surfaces of each roller 22, 24 is pulled inward toward the roll gap 23 and passes through the roll gap 23 in the longitudinal direction (X).

[0086] Fiber reinforcement 10 is supplied from an earlier stage of a continuous process (not shown). In this particular embodiment, fiber reinforcement 10 is a carbon fiber mesh with a width of 1400 mm and a maximum thickness of 0.5 mm. Fiber reinforcement 10 is received on the receiving side (e.g., Figure 1 The left side of the first roller 22 (as shown) contacts the first roller 22, and then it is pulled clockwise around the first roller 22 toward the roll gap point 23.

[0087] The slit die 30 is arranged on the receiving side of the second roller 24 (e.g., Figure 1 (The left side of the second roller 24 is shown). The slit die 30 is configured to deliver resin 32 onto the surface of the second roller 24. The resin 32 is then pulled counterclockwise around the second roller 24 toward the nip point 23. Although the resin 32 on the surface of the second roller 24... Figure 1 The coating is shown as discontinuous, but this is for illustration only (to distinguish it from reinforcing material 10), and resin 32 forms a substantially continuous coating on the surface of the second roller 24, which spans a width approximately equal to the width of reinforcing material 10 (i.e., approximately 1400 mm).

[0088] In this particular embodiment, resin 32 is a modified epoxy resin with a curing temperature of 120ºC.

[0089] Slit mold head 30 and conduit for supplying resin to the slit mold head ( Figure 1 (Not shown) is heated. Heating the slit die 30 and / or the supply pipe preheats the resin 32 before it contacts the second roller 24. In this particular embodiment, the slit die 30 is heated to a temperature of 100ºC. This temperature effectively reduces the viscosity of the resin 32, allowing it to flow through the slit die 30 and adhere to the surface of the second roller 24, but remains below the curing temperature. When using different resins with different curing temperatures, the heating temperature of the slit die 30 can be adjusted as needed to obtain the desired resin viscosity while preventing premature resin curing.

[0090] The first roller 22 and the second roller 24 are also heated. Heating the first roller 22 causes some heating of the fiber reinforcement material as it comes into contact with the first roller 22 before reaching the nip point 23. Heating the second roller 24 ensures that the temperature of the resin 32 in contact with the second roller 24 remains elevated to reduce the viscosity of the resin 32. In this particular embodiment, both the first roller 22 and the second roller 24 are heated to a temperature of 105ºC, but this can be adjusted as needed for different resin / fiber reinforcement combinations.

[0091] When the fiber reinforcement 10 and resin 32 reach the roll gap point 23, they come into contact with each other due to the narrow gap between the first roller 22 and the second roller 24. At the roll gap point 23, the distance between the first roller 22 and the second roller 24 is less than the combined thickness of the resin 32 coating on the fiber reinforcement 10 and the second roller 24. Therefore, the resin 32 and the fiber reinforcement 10 are forced together at the roll gap point 23 (i.e., pressure is applied by the first roller 22 and the second roller 24). This results in the resin 32 impregnating the fiber reinforcement 10 (i.e., penetrating into the fiber structure and coating both the inner filaments and the surface filaments). This results in the formation of a molding material 12 consisting of the fiber reinforcement 10 impregnated with uncured resin 32.

[0092] By heating the resin 32 on the second roller 24 in the slit die 30, when the resin 32 reaches the roll gap point 23, the resin 32 has a viscosity optimized for impregnating (i.e., flowing into) the internal structure of the fiber reinforcement 10. In this particular embodiment, the viscosity of the resin 32 at the roll gap point 23 is between 1 and 100 Pa·s.

[0093] Given the small area of ​​the roll gap point 23 and the dimensions, location, and thermal mass of the first roll 22 and the second roll 24, it is impossible to directly and accurately measure the temperature of the resin 32 and / or fiber reinforcement 10 at the roll gap point 23. However, understanding the full thermal history of the resin 32 is important for understanding whether it is close to its TMR and for understanding the degree of fiber wetting that occurs at the roll gap point 23 (the impregnation of the resin 32 into the fiber reinforcement 10). Both of these factors can affect the quality and lifespan of the final prepreg product.

[0094] Therefore, system 1 includes a series of infrared temperature sensors 40-50 arranged along the path of the molding material 12 following the impregnation system 20. Figure 1 In this implementation, there are a total of eight individual infrared temperature sensors 40, 41, 42, 43, 44, 45, 46, and 50, which are equidistant from each other by a sensor distance D2. The first temperature sensor 40 is separated from the roll gap point 23 in the impregnation system 20 by a first separation distance D1. Each sensor 40-50 is positioned above the molding material 12 at an equal height D3. Each temperature sensor communicates with a processor (not shown) and a display (not shown).

[0095] In this particular embodiment, D1 is minimized. In other words, given the physical constraints of the rollers 22, 24 and any associated support structures (not shown) and the thermal constraints of any radiant heat from the rollers 22, 24, the first sensor 40 is positioned as close as possible to the roll gap point 23, where the radiant heat could affect the accuracy of the temperature measured by the first sensor 40 if D1 is too small. Minimizing D1 in this way minimizes the error in determining the temperature at the roll gap point 23. In this particular embodiment, the roller diameter is approximately 90 mm and D1 is 50 mm; however, the actual minimum distance for D1 will vary depending on system parameters such as the dimensions of the rollers and surrounding equipment, and the thermal mass of the rollers and any surrounding equipment.

[0096] In this particular embodiment, the inter-sensor spacing distance (D2) is 25 mm. Therefore, the spacing distance between the second sensor 41 and the roll gap point 23 is 75 mm; the spacing distance between the third sensor 42 and the roll gap point 23 is 100 mm; the spacing distance between the fourth sensor 43 and the roll gap point 23 is 125 mm; the spacing distance between the fifth sensor 44 and the roll gap point 23 is 150 mm; the spacing distance between the sixth sensor 45 and the roll gap point 23 is 175 mm; the spacing distance between the seventh sensor 46 and the roll gap point 23 is 200 mm; and finally (eighth) the spacing distance between the eighth sensor 47 and the roll gap point 23 is 225 mm.

[0097] As the molding material 12 moves away from the impregnation system 20 in the longitudinal direction (X), it gradually cools. Temperature sensors 40-50 measure the temperature of the molding material 12 at different distances from the roll gap point 23 (and therefore at different times since the heating step). In this embodiment, the linear velocity is 25 mm / s (i.e., the fiber reinforcement 10 and the molding material 12 move through the system 1 at a rate of 25 mm / s). Therefore, two seconds after impregnation / heating at the roll gap point 23, the first sensor 40 measures the temperature of the molding material 12. Therefore, nine seconds after impregnation / heating at the roll gap point 23, the last sensor 50 measures the temperature of the molding material 12. Intermediate sensors 41-46 are spaced apart such that, after the heating step, the temperature of the molding material 12 is measured at one-second intervals between two and nine seconds.

[0098] Now for reference Figure 4 The temperatures of the molding material 12, measured by each temperature sensor 40-50 at different times after the impregnation / heating step, were plotted on a graph. Using Newton's law of cooling as the decay model, an exponential decay curve was fitted to the data points, and the initial temperature T could be extrapolated from the fitted curve. h (That is, the temperature of the molding material 12 at the roll gap point 23). The graph is provided for illustration: in fact, the processor uses an algorithm to derive the coefficients in Newton's law of cooling, without plotting the graph (e.g., by solving simultaneous equations or least squares regression). In this particular embodiment, the initial temperature T h It was calculated to be 96.77ºC.

[0099] Figure 4 It also shows (as square points) from the ninth temperature measurement point ( Figure 1 The ninth temperature measuring point (not shown) is positioned 250 mm away from the roll gap point 23. This temperature measuring point is located near an additional heat source, which is positioned along the material path (…). Figure 1 Further downstream (not shown in the diagram) (300 mm from roll gap point 23). The proximity of the additional heat source at the ninth measurement point affects the cooling of the material and the accuracy of temperature measurement, and therefore, this point is excluded from data analysis.

[0100] The calculated temperature extrapolated from the fitted curve is notably lower than the set heating temperature (105ºC) of the first roller 22 and the second roller 24 (a difference of slightly more than 8ºC). This is to be expected: the resin 32 and the fiber reinforcement 10 only come into contact with the heated surfaces of the rollers 22, 24 for a short distance / time. Therefore, they do not fully heat / balance the temperature of the rollers 22, 24 through the roll gap point 23 and remain at a lower temperature. Therefore, it is inaccurate to make the roller temperature equal to the temperature of the molding material 12 at the roll gap point 23. An inaccuracy of 8ºC is considerable because such a temperature difference can cause an order-of-magnitude change in the resin viscosity.

[0101] The temperature of the molding material 12 at roll gap 23 can be determined more accurately by measuring the temperature of the molding material 12 at different points after the roll gap point and extrapolating it based on the fitted model (depending on the accuracy of the fitted model).

[0102] In continuous processes (such as using System 1), the temperature of the molding material 12 can be measured at regular sampling intervals using each of temperature sensors 40-50. This data can be input into a processor, which can analyze the temperature data in real time based on a fitted model to determine the temperature of the molding material 12 at roll gap point 23. The processor can evaluate the temperature of the molding material 12 at roll gap point 23 against an acceptable temperature range, and when it is within the acceptable range, no action is required. However, if the temperature of the material 12 at roll gap point 23 exceeds (is above or below) the acceptable temperature range for a particular resin / fiber reinforcement combination, the processor can control the heaters in rollers 22, 24 and / or slit die 30 and the resin supply pipe to adjust the heating temperature so that the material temperature at roll gap point 23 returns to the acceptable range. The processor can also record any portion along the length of the molding material 12 where the temperature is outside the acceptable range, thus enabling further inspection of the quality of these portions or removal of these portions from the final product.

[0103] Referring now to Figure 6, an analysis is performed to demonstrate the accuracy of the above-described fitted model based on Newton's law of cooling. The roller temperature was controlled to vary over time to determine how accurately the system and the fitted model tracked the temperature changes. The roller temperature variations were more extreme than expected during normal operation. Figure 6A The diagram shows a comparison between the predicted temperatures (note that this is not the temperature of the molding material 12 itself) of the first roll 22 and the second roll 24 at roll gap point 23, obtained using the above fitting model, and the actual roll temperatures. The data to the left of the vertical dashed line represents the initial balancing period of the machine and therefore has finite values, while the data to the right of the vertical dashed line represents values ​​after the system has reached a stable state. Figure 6AAs shown, even under extreme temperature fluctuations, the fitted model provides a reasonably accurate prediction of the actual roll temperature, and therefore is likely to provide a reasonably accurate determination of the material temperature. The model has a slight tendency to overestimate the peak temperature.

[0104] Figure 6B The comparison shows the first derivative (i.e., rate of change) of the actual roll temperature over time. Figure 6A The difference (error) between the actual and predicted temperatures is shown. The first derivative of the actual roll temperature and the error of the predicted temperature follow similar curves over time, but there is a noticeable phase lag in the predicted data. This is expected because the predicted temperature at a given time t is based on temperature measurements taken between t + 2 and 9 seconds. However, Figure 6B This indicates that the prediction model can accurately track the temperature change at the roll gap point 23.

[0105] Referring now to Figure 7, a series of tests are performed to demonstrate the first temperature sensor 40 and the last temperature sensor 50. Figure 7A ) and intermediate sensor 43 ( Figure 7B The impact of the distance between the two sides on the accuracy of the fitted model.

[0106] Figure 7A The relative distance (span) between the first and last sensors and the overall position of the sensors relative to the heating point (the midpoint of the sensor array; i.e., the relative distance from the heating point to the midpoint between the first and last sensors) are shown to affect the model accuracy.

[0107] like Figure 7A As shown, the error is minimized when the first sensor 40 is as close as possible to the roll gap point 23 and the last sensor 50 is as far away from the roll gap point 23 as possible (within the constraints of System 1), i.e., when the span is maximized. When the span is not maximized, the closer the center point of the sensor array is to the heating point, the smaller the error (i.e., ...). Figure 7A The smaller the relative value in the middle.

[0108] Figure 7B The contribution of the intermediate sensor 43 position to the error is shown relative to both spatial (positional) and temperature separations. Minimum error was observed when the intermediate sensor 43 was positioned at the midpoint between the temperatures of the first and last sensors. In terms of distance, this corresponds to a position approximately one-third the distance between the first and last sensors (closer to the first sensor).

[0109] Within a wide range of intermediate distances or temperatures, the error is less sensitive to the position of the intermediate sensor 43, but the position of the intermediate sensor 43 contributes more to the error when positioned toward extreme values ​​(maximum or minimum). Therefore, it seems to be the optimal configuration to position the first sensor 40 at the minimum distance; the last sensor 50 at the maximum distance; and one or more intermediate sensors between the first sensor 40 and the last sensor 50 to provide additional data points (to improve the accuracy of the fitted model).

[0110] Now for reference Figure 2 A portion of an alternative system 100 for performing a continuous process on materials is shown in a simplified form (not to scale). This continuous process is also a process for forming a molded material in the form of a preimpregnated composite material (prepreg) consisting of fiber reinforcement 110 and a matrix composed of resin 132, which is impregnated into the fiber reinforcement 110.

[0111] Figure 2 A portion of system 100 is shown, configured to combine fiber reinforcement 110 with resin 132 to form molding material 112. System 100 includes an impregnation system 120, which includes a first heated roller 122 and a second heated roller 124.

[0112] In this particular embodiment, the first heating roller 122 and the second heating roller 124 are arranged in an S-shaped winding configuration and configured to rotate in opposite directions to each other. In this particular embodiment, the first heating roller 122 is configured to rotate counterclockwise, and the second heating roller 124 is configured to rotate clockwise.

[0113] Fiber reinforcement 110 is supplied from an earlier stage of a continuous process (not shown) and is the same as the fiber reinforcement 10 described above.

[0114] Fiber reinforcement 110 is supplied via guide roller 126 to a receiving point on the second roller 124. Then, before contacting and winding with the first roller 122, the fiber reinforcement 110 is drawn around the second roller 124. Thus, as... Figure 2 As shown, the fiber reinforcement 110 follows a generally S-shaped path through the second roller 124 and the first roller 122.

[0115] The slit die 130 is arranged approximately one-quarter turn (90 degrees) upstream of the receiving point on the second roller 124 (i.e., when the fiber reinforcement 110 contacts the second roller 124). The slit die 130 is similar to the slit die 30 and is configured to deliver resin 132 (the same as resin 32 in this particular embodiment) onto the surface of the second roller 124. The resin 132 is then drawn clockwise around the second roller 124 toward the receiving point. Although the resin 132 on the surface of the second roller 124... Figure 2 The coating is shown as discontinuous, but this is for illustration only (to distinguish it from reinforcing material 110), and resin 132 forms a substantially continuous coating on the surface of the second roller 124, which spans a width approximately equal to the width of reinforcing material 110 (i.e., approximately 1400 mm).

[0116] Slit mold head 130, conduit for supplying resin to the slit mold head ( Figure 2 (not shown in the image) and the first roller 122 and the second roller 124 are heated as described above with respect to system 1.

[0117] When the fiber reinforcement 110 and resin 132 reach the receiving point on the second roller 124, they come into contact with each other. The tension in the fiber reinforcement 110 through the impregnation system 120 causes the fiber reinforcement 110 and resin 132 to be pushed against the surfaces of the first roller 122 and the second roller 124, causing the resin 132 to impregnate the fiber reinforcement 110 to form the molding material 112.

[0118] By heating the resin 132 on the surface of the second roller 124 in the slit die 130, the resin 132 reaches a viscosity optimized for impregnating (i.e., flowing into) the internal structure of the fiber reinforcement 110 when it reaches the receiving point. In this particular embodiment, the viscosity of the resin 132 at the receiving point is between 1 and 100 Pa·s. By heating the combined fiber reinforcement 110 and resin 132 as they pass around the first roller 122, the elevated temperature can be maintained for a longer period to improve the impregnation / wetting of the fiber reinforcement by the resin 132.

[0119] Similar to the impregnation system 20, directly measuring the temperature of the molding material 112 when it is heated (i.e., when it is kept in contact with the first roller 122 or the second roller 124) is challenging due to the thermal mass of the first roller 122 and the second roller 124.

[0120] Therefore, system 100 includes an infrared temperature sensor 140, which is positioned at a point along the path of the molding material 112 following the impregnation system 120. In such a way... Figure 2 As shown in the initial position, the temperature sensor 140 is separated from the end of the heating point (i.e., the point where the molding material 112 leaves the surface of the first roller 122) by a first separation distance D1, which is the smallest in this particular embodiment (as described above) and is 75 mm.

[0121] In this particular embodiment, the temperature sensor 140 is movably mounted on the guide rail 160. The temperature sensor 140 includes a drive motor (not shown) operable to drive the sensor 140 to travel along the rail 160 in the longitudinal direction (X) at an initial position (e.g., Figure 2The measured distance (D4) between the temperature sensor 140 and the final position 150 is shown. The temperature sensor 140 is connected to the processor (not shown).

[0122] In use, temperature sensor 140 is operable to record the temperature of molding material 112 at a first distance (D1) from impregnation system 120. After recording the temperature at the first distance (D1), a drive motor can be activated to move temperature sensor 140 along track 160 in the longitudinal direction (X) at the same rate as the molding material 112 moves in the longitudinal direction (X). As the temperature sensor moves between the initial position and the final position 150, it continues to record the temperature of molding material 112 (at set intervals). As it moves at the same rate as molding material 112, temperature sensor 140 records the temperature change at a single point of molding material 112 as it moves away from impregnation system 120. This data is then processed by a processor as described above using the fitting model as described above to determine the temperature of material 112 at the point where it exits the first roller 122. By measuring the temperature change at the same point of molding material 112, any error in local fluctuations of material temperature can be minimized compared to system 1 (albeit at the cost of time resolution for continuously determining temperature conditions at the heating step).

[0123] Now for reference Figure 3 A portion of another alternative system 200 for performing a continuous process on materials is shown in a simplified form (not to scale). This continuous process is also a process for forming a molded material in the form of a preimpregnated composite material (prepreg) consisting of fiber reinforcement 210 and a matrix composed of resin 232, which is impregnated into the fiber reinforcement 210.

[0124] System 200 includes impregnation system 220, which is substantially the same as impregnation system 120 (the same features are given by the same reference numerals plus 100).

[0125] Similar to System 1 (and different from System 100), System 200 includes a plurality of fixed infrared temperature sensors 240, 242, 244 and 250 arranged along the path of the molding material 212 after the impregnation system 220.

[0126] The first sensor 240 is spaced D1 from the impregnation system 220. As in system 1, D1 is minimized. In this embodiment, the intermediate sensors are not uniformly spaced relative to the distance from the heating point, but rather spaced such that each intermediate sensor 242, 244 is positioned at a point where the temperature of the material 212 is approximately the average of the temperatures recorded at two adjacent sensors. Because the cooling of the material 212 does not occur linearly, the spacing (D2, D5, and D6) between adjacent sensors is not equal, but increases with increasing distance from the impregnation system 220.

[0127] Unlike Systems 1 and 100, the continuous process of System 200 includes a further heating step. After passing through the final temperature sensor 250, the molding material 212 passes through a partially enclosed IR oven 270, in which infrared radiation is directed at the molding material 212 to further promote the impregnation of the resin 232 into the fiber reinforcement 210.

[0128] Finally, the position of the sensor 250 relative to the immersion system 220 is maximized, while being sufficiently spaced from the IR oven 270 (separation distance D7) to ensure that the accuracy of the temperature reading at the sensor 250 is not affected by the radiant heat escaping from the IR oven 270.

[0129] After the molding material 212 has undergone further heating, its cooling is further measured by a further temperature sensor 280. Like temperature sensor 140, the further temperature sensor 280 is mounted on a track 290 and can be positioned in the initial position (e.g., Figure 3 The initial position (shown) moves at the same speed as material 212 between the final position 282 and the initial position to record the temperature change at a single point. The initial position is spaced from the end of the IR oven 270 by a distance D7. D7 is minimized as described above (i.e., as small as possible, so that radiant heat from the oven 270 does not affect the accuracy of the temperature reading).

[0130] Temperature sensors 240, 242, 244, 250 and 280 are connected to a processor (not shown) that can process temperature data and model the highest temperature of material 212 at the end of impregnation system 220 and in IR oven 270.

[0131] Now referring to Figure 5, in Figure 3 A series of tests were conducted on the system 200 to demonstrate the effect of changing the linear velocity ( Figure 5A ), thermal diffusivity of the material ( Figure 5B ) and heat transfer coefficient ( Figure 5C The effect of temperature curve relative to distance from the impregnation system 220.

[0132] Figure 5AThis shows the reduction of the linear velocity by half to 12.5 mm / s ( Figure 5A The "×1" (25 mm / s) indicates that the material 212 cools more over the same distance, while doubling the linear velocity reduces the cooling. As the material 212 enters the IR oven 270, the temperature rises again to the right of the curve.

[0133] Figure 5C This shows that increasing the heat transfer coefficient leads to a significant increase in the cooling rate. For example... Figure 5B As shown, relative to 3.9 e -4 m 2 At a baseline of / s, doubling or halving the thermal diffusivity (i.e., the ability of heat energy to diffuse along the length of the material) of material 212 is not as significant as changing the linear velocity or the heat transfer coefficient.

[0134] Referring now to Figure 8, the effects of varying the linear velocity and sensor spacing on the accuracy of the model when predicting the initial temperature were investigated. A simplified model system was used for the data shown in Figure 8. The molding material (similar to molding material 12) was heated at the heating point using an IR lamp. Downstream of the heating point, an array of four temperature sensors was arranged, with each sensor equidistantly spaced 50 mm apart. Figure 8A ) or 100 mm ( Figure 8B Alternatively, the distance between the first and second sensors, and between the second and third sensors, may be unequal, with a spacing of 300 mm; and the distance between the third and fourth sensors may be 280 mm. Figure 8C and Figure 8D The linear velocity is 3 m / min. Figure 8A and Figure 8B ), 6 m / min Figure 8C ) and 10 m / min ( Figure 8D The variation between )

[0135] refer to Figure 8A and Figure 8B This illustrates the impact of increasing the spacing between sensors on the model's prediction accuracy. (Compared to...) Figure 8B Compared to the larger spacing shown, as Figure 8A The smaller sensor spacing shown (i.e., the sensors are positioned closer to the heating point and closer to each other) results in more accurate tracking of the actual temperature at the verification point (the first sensor).

[0136] refer to Figure 8C and Figure 8D This illustrates the effect of increasing linear velocity on the model's prediction accuracy. At two faster speeds, 6 m / min ( Figure 8C ) and 10 m / min ( Figure 8D At ) and running at 3 m / min ( Figure 8A and Figure 8B In contrast, there is a significant lag between the predicted and actual data. The actual temperature is lower because the increased linear velocity reduces the material's heating time. However, in both cases, the predicted temperature reasonably tracks the actual temperature. Any time lag can be corrected during data post-processing.

Claims

1. A method for determining the temperature reached by a material of a certain length during a heating step in a continuous process, comprising the following steps: After the heating step, the temperature of the material is measured at one or more distances along its length; as well as The temperature of the material at the heating step is calculated based on the temperature at one or more distances along the length of the material.

2. The method according to claim 1, wherein the temperature at the heating step is calculated based on Newton's law of cooling.

3. The method according to claim 1 or claim 2, wherein the heating step includes contacting the material with a heated surface, contacting the material with a heated material, or indirectly heating it.

4. The method according to any one of the preceding claims, wherein the material is in the form of a strip.

5. The method according to any one of the preceding claims, wherein the material comprises a resin.

6. The method according to claim 5, wherein the resin is a thermosetting resin.

7. The method according to any of the preceding claims, wherein the material is a composite material.

8. The method according to any one of the preceding claims, wherein the step of measuring the temperature of the material comprises measuring the temperature of the material at two or more distances along the length of the material after the heating step; and wherein the step of calculating the temperature of the material comprises calculating the temperature of the material at the heating step based on the temperature at the two or more distances along the length of the material.

9. The method of claim 8, wherein the first distance at which the temperature of the material is measured is minimized relative to the heating step.

10. The method of claim 8 or 9, wherein the final distance at which the temperature of the material is measured is maximized relative to the heating step.

11. The method according to any one of the preceding claims, wherein the step of measuring the temperature of the material comprises measuring the temperature of the material at three or more distances along the length of the material after the heating step; and wherein the step of calculating the temperature of the material comprises calculating the temperature of the material at the heating step based on the temperature at the three or more distances along the length of the material.

12. The method of claim 11, wherein, relative to the heating step, a first distance at which the temperature of the material is measured is minimized; a final distance at which the temperature of the material is measured is maximized relative to the heating step; and one or more intermediate distances at which the temperature of the material is measured are such that the temperature measured at the intermediate distance is approximately equal to the average of two adjacent distances (mean).

13. The method according to any one of the preceding claims, wherein the continuous process includes a further heating step, and the method further includes the following steps: The temperature to which the material was heated during the further heating step was determined by measuring the temperature of the material at one or more distances along the length of the material after the further heating step; and The temperature of the material at the further heating step is calculated based on the temperature at one or more distances along the length of the material after the further heating step.

14. The method according to any one of the preceding claims, wherein the continuous process is a process of impregnating a reinforcing material layer with resin.

15. The method of claim 14, wherein the resin is a thermoplastic resin or a thermosetting resin.

16. The method according to any one of claims 1 to 13, wherein the continuous process is a process of forming a film from a polymer or thermosetting resin precursor.

17. The method according to any one of the preceding claims, further comprising the following steps: Monitor the temperature to which the material is heated during the heating step; and If the temperature to which the material is heated drops below or above a specified value, the process conditions are adjusted.

18. A method for monitoring the temperature to which a molding material is heated during an impregnation step in a continuous manufacturing process, comprising the following steps: Combining a fiber reinforcement layer with a thermoplastic or thermosetting resin layer, and impregnating the resin at least partially into the fiber reinforcement layer in an impregnation step to form a molded material that is at least partially impregnated; After the impregnation step, the temperature of the at least partially impregnated molding material is measured at one or more distances along the length of the molding material; as well as The temperature to which the molding material is heated during the impregnation step is calculated based on the temperature at one or more distances along the length of the molding material.

19. The method of claim 18, wherein the temperature at the impregnation step is calculated based on Newton's law of cooling.

20. The method of claim 18 or claim 19, wherein the impregnation step comprises contacting the fiber reinforcement layer and the thermoplastic or thermosetting resin layer with a heated surface and applying pressure.

21. The method according to any one of claims 18 to 20, wherein the molding material is in the form of a strip.

22. The method of any one of claims 18 to 21, wherein the step of measuring the temperature of the at least partially impregnated molding material comprises measuring the temperature of the molding material at two or more distances along the length of the molding material after the impregnation step, and wherein the step of calculating the temperature to which the molding material is heated comprises calculating the temperature of the molding material during the impregnation step based on the temperatures measured at the two or more distances along the length of the molding material.

23. The method of claim 22, wherein the step of measuring the temperature of the at least partially impregnated molding material comprises measuring the temperature of the molding material at three or more distances along the length of the molding material after the impregnation step, and wherein the step of calculating the temperature to which the molding material is heated comprises calculating the temperature of the molding material during the impregnation step based on the temperatures measured at the three or more distances along the length of the molding material.

24. The method according to any one of claims 18 to 23, wherein the continuous manufacturing process includes a heating step after the impregnation step, and wherein the temperature to which the molding material is heated during the heating step is determined by measuring the temperature of the molding material at one or more distances along the length of the molding material after the heating step; and the temperature to which the molding material is heated at the heating step is calculated based on the temperature at the one or more distances along the length of the molding material.

25. The method according to any one of claims 18 to 24, comprising the following steps: Monitor the temperature to which the molding material is heated during the impregnation step; as well as If the temperature of the molding material drops below or above a specified value, the process conditions are adjusted.

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