Charge heating method and system for induction molding

Abstract

The present disclosure relates to an electric charge heating method and system for induction molding. A method and system for heating a material includes an induction coil, an inductor providing a container, and at least one nozzle, wherein the container is configured to hold the material, and the at least one nozzle is used to spray a heated gas onto and / or into the material. In the method, the inductor is heated by the induction coil, and heat energy from the inductor can be transferred to the material. In addition to being heated by heat from the inductor, the material is also heated by the heated gas, thereby increasing the heating rate of the material to quickly heat the material to a processing temperature. The system may include other components, such as a gas source, at least one conduit for conveying gas from the gas source to at least one nozzle, and a heat source for heating the gas before spraying the gas from the at least one nozzle.

Description

Technical Field

[0001] The present disclosure relates to the field of thermal control of materials, and more particularly, to heating materials using smart susceptors. Background Art

[0002] A susceptor is a material that converts electromagnetic energy into heat and can be used to heat various materials, for example, in manufacturing processes. Smart sensors are sensor components that are self-regulating with respect to temperature. Typically, smart sensors are placed in an electromagnetic flux field generated by an inductor. Inductor materials include various ferromagnetic materials, such as iron-nickel-cobalt alloys such as Kovar. and other iron, nickel and cobalt alloys.

[0003] At relatively low temperatures, the inductor has high permeability to the electromagnetic flux field, and the cross-sectional area through which electrons flow through the inductor (i.e., the skin depth) is small. Therefore, at these relatively low temperatures, the resistance of the inductor is relatively high. When placed in an electromagnetic flux field, such as that generated by an induction coil that is part of a smart sensor assembly, the inductor begins to inductively heat due to the initial small skin depth and high magnetic permeability. As the inductor heats, the thermal profile of the inductor asymptotically approaches its leveling temperature. The leveling temperature is the temperature at which the inductor maintains thermal equilibrium without further increase in temperature even in the presence of a magnetic flux field, and the leveling temperature depends at least in part on the environmental conditions surrounding the inductor. The leveling temperature is typically higher than the design "Curie" temperature or "T" of the smart sensor. C "A few degrees below (e.g., within 2°F, or within 10°F, or within 50°F, or within 100°F), where the inductor becomes nonmagnetic at the Curie temperature. As the inductor approaches its leveling temperature, the inductor's magnetic permeability decreases, which increases the skin depth, thereby attenuating the inductor's resistance and reducing the heating effect. The reduction in magnetic permeability limits the heat generation at those portions of the inductor that are at or near the leveling temperature. The magnetic flux of the inductor moves to the lower temperature portions with higher magnetic permeability, thereby causing those portions of the inductor below the leveling temperature to heat more quickly toward the leveling temperature. Leveling Temperature Heating. The magnetic permeability at a given point in time can be different for different regions of the inductor, depending on the local temperature of the local region. As each local region of the inductor approaches the leveling temperature, the local region becomes increasingly nonmagnetic until a steady state (i.e., thermal equilibrium) is reached, and further heating of the inductor at that local region is stopped. Regions of the inductor that reach the Curie temperature become nonmagnetic at or above the Curie temperature. As the inductor begins to cool, its magnetic permeability increases, its skin depth decreases, its resistance increases, and the heating process begins again.

[0004] Smart sensors are valuable tools in manufacturing and other applications because of their temperature self-regulating properties. Summary of the invention

[0005] A simplified summary of the invention is presented below to provide a basic understanding of some aspects of one or more implementations of the present disclosure. This summary is not an extensive review, nor is it intended to identify key or important elements of the present disclosure, nor is it intended to describe the scope of the present disclosure. Instead, its primary purpose is simply to present one or more concepts in a simplified form as a preface to a detailed description presented later.

[0006] In one implementation of the present disclosure, a method for heating a material includes placing the material in a container of an inductor assembly, heating an inductor of the inductor assembly using a magnetic flux field emitted by an induction coil, and heating the material in the container with a heated gas directed to engage the material. The method may also include flowing a gas from a gas source into a conduit in fluid communication with the gas source, and heating the gas in the conduit to form a heated gas, wherein heating the material further includes ejecting the heated gas from the conduit through a nozzle to engage the material. The material may be a quantity of material in particulate form, and the heating of the material may also include placing a nozzle into the container and into the quantity of material before heating the material with the heated gas.

[0007] Alternatively, the material may have a processing temperature, and the method may further include stopping heating the material with the heated gas before the material reaches the processing temperature, and further heating the material to the processing temperature using heat transferred to the material from the inductor after stopping heating the material with the heated gas. The method may further include heating the material within the container of the inductor assembly with the inductor of the inductor assembly.

[0008] In one implementation, the inductor may define at least a portion of the first die surface, and the method may further include heating the second die surface with a magnetic flux field emitted by the induction coil, stopping heating the material with the heated gas before the material reaches a processing temperature of the material, and heating the material to the processing temperature within the container using heat transferred from the inductor to the material after stopping heating the material with the heated gas, and engaging the material with the second die surface. The inductor may be heated to a Curie temperature at which the inductor transitions from magnetic to non-magnetic.

[0009] In another implementation, a molding process includes placing a molding material having a processing temperature within a container defined by an inductor assembly, wherein the inductor assembly includes an inductor, the inductor defines a die face, and the die face is in thermal communication with the molding material. The method of this implementation also includes heating the molding material at a first heating rate with heated gas directed to the molding material, and heating the die face at a second heating rate by directing a magnetic flux field at the inductor, wherein the first heating rate and the second heating rate raise the temperature of the molding material and the die face to within 5°F of the processing temperature within a time period of 300 seconds of each other.

[0010] Optionally, the heating of the mold surface has a first temperature profile for a first duration, wherein the first duration begins when the magnetic flux field is first directed at the inductor and ends when the molded material reaches a processing temperature, the heating of the molded material has a second temperature profile for a second duration, wherein the second duration begins when the heated gas is first directed to the molded material and ends when the molded material reaches the processing temperature, the first duration begins simultaneously with the second duration, and the first temperature profile does not vary by more than 20°F relative to the second temperature profile over the first duration and the second duration. The first duration and the second duration may be between 3.5 minutes and 7.0 minutes. In addition, the molding process may include stopping heating the molded material with the heated gas when the processing temperature is reached ±25°F.

[0011] The molding process may also include flowing gas from a gas source into the conduit and heating the gas in the conduit to form a heated gas, wherein the heating of the material includes ejecting the heated gas through a nozzle to engage the material. The molding material may be a quantity of molding material in a granular form, and the heating of the material may include placing the nozzle into a container and into the quantity of molding material before heating the molding material with the heated gas. The first heating rate and the second heating rate may be from 100°F / minute (°F / min) to 200°F / min.

[0012] In another implementation of the present disclosure, a system for heating a molding material includes an inductor assembly including an inductor, wherein the inductor defines a container configured to contain the molding material, and the inductor further defines a molding surface. The system also includes a gas injector configured to direct a heated gas toward the molding material placed in the container. The gas injector may include a nozzle and a conduit in fluid communication with the nozzle, the nozzle may be configured to direct the heated gas from the conduit toward the molding material, and the system may also include a heat source configured to heat the gas in the conduit.

[0013] Optionally, the system further includes a plurality of gas injectors, each gas injector having a nozzle and a conduit in fluid communication with the nozzle, wherein the nozzle of each gas injector in the plurality of gas injectors is configured to direct heated gas toward the molding material. The system may also include an induction coil configured to emit a magnetic flux field toward the inductor. In one implementation, the inductor has a Curie temperature at which the inductor transitions from magnetic to non-magnetic. In addition, the gas injector may be non-magnetic. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate implementations of the present disclosure and, together with the specification, are used to explain the principles of the present disclosure. In the drawings:

[0015] Figure 1 is a schematic cross-sectional view of a system for heating a material according to an implementation of the present disclosure.

[0016] Figure 2 yes Figure 1 a cross section of the structure during the molding process;

[0017] Figure 3 is a cross section of the material after the molding process and after the material is removed from the system.

[0018] Figure 4 is a schematic plan view of another implementation of a system for heating a material according to the present disclosure.

[0019] Figure 5 a first graph showing a heating profile of a conventional system and a second graph showing a heating profile of a system according to the present disclosure;

[0020] Figure 6 It is a flowchart or a schematic flowchart of a method according to an implementation mode of the present disclosure.

[0021] It should be noted that some details of the drawings have been simplified and have been drawn to facilitate understanding of the present disclosure rather than maintaining strict structural accuracy, detail, and scale. DETAILED DESCRIPTION

[0022] Reference will now be made in detail to exemplary implementations of the present disclosure, examples of which are illustrated in the accompanying drawings. In general and / or where convenient, the same reference numerals are used throughout the drawings to designate the same or similar parts.

[0023] As described above, smart sensors are useful tools in manufacturing and other applications, in part because of their thermal self-regulation capabilities. In a flat (i.e., planar or blanket) configuration, a smart sensor can maintain a generally uniform temperature across the sensor, such as within 20°F or within 10°F of its designed leveling temperature. A smart sensor can be designed to approach a predetermined leveling temperature by, for example, selecting a percentage of one or more component materials of the sensor, such as a percentage of one or more metal or metal alloy components. The leveling temperature also depends to a lesser extent on factors such as magnetic field strength.

[0024] Smart sensors can be used for many different purposes and configurations. In some applications, sensors can be formed to encapsulate or coat solid structures to be heated to a specific temperature, such as during a drying or curing process. In other applications, sensors can be formed or shaped to provide a container. The container can be used, for example, to hold and heat materials such as thermosetting, thermoplastic or molding materials, or configured for other purposes. For example, U.S. patent application serial number 15 / 791,683, entitled "Induction Molding for Parts Having Thermoplastic Portions," filed on October 24, 2017, discusses molding structures and processes including smart sensors. Because these materials are typically heated to the critical processing temperature or other target temperature of use, and overheating exceeding the target temperature is avoided, smart sensors can be particularly well suited for such processes simply because smart sensors are self-regulating with respect to temperature.

[0025] The material within the container of the shaped inductor is heated to a suitable temperature for processing the material, which may have different time requirements depending on, for example, the thermal characteristics of the material being heated and the form of the material being heated. For some materials, the processing temperature is the melting point of the material, or the melting point of at least one component of the material. For some materials, the processing temperature is a temperature below the melting point of the material (or the melting point of at least one component of the material), but at which the material softens to the extent that it can be formed into the desired shape. Generally, materials with high thermal conductivity have better heating distribution (i.e., the material can reach the processing temperature in a shorter time) than materials that are poor thermal conductors. In addition, solid blocks will generally have better heating distribution than highly porous materials.

[0026] In one type of molding process for forming a molded part, the raw material to be molded (i.e., the "charge") is placed in a container and then heated to a suitable processing temperature (e.g., melted, made flowable, etc.) to facilitate molding. The charge can be, for example, a composite material including carbon fibers pre-impregnated with a thermoplastic, commonly referred to as a prepreg. Prepregs can be prepared in different forms, for example, the prepregs can have chopped, granular, sheet-like, segmented, single and / or another particle form (hereinafter collectively referred to as "particles"). The processing temperature of the prepreg is generally the softening point or melting point of the thermoplastic part. In particular, this form of prepreg has low thermal conductivity and high porosity. In this way, the prepreg may be difficult to heat to, for example, the processing temperature in terms of the time required for the prepreg to reach the processing temperature. This demand will increase manufacturing costs and equipment costs. According to an implementation of the present disclosure, a heating system and method may be provided, which reduces the duration required to heat a charge in a container, improves production yield, and reduces manufacturing costs compared to some conventional heating systems and methods.

[0027] Figure 1 is a schematic cross-section of a system 100 for heating a material 102 according to an implementation of the present disclosure. Figure 1 The system 100 may be, for example, part of a molding system used during a molding process, or another type of system for heating a material 102 such as the chopped prepregs described above, in which case the material 102 represents a loose mass of discrete prepregs. Figure 1 A gas source 104 is shown in fluid communication with at least one conduit 106, wherein the conduit 106 is or includes a gas injector 106 in fluid communication with at least one nozzle 108 and provides a passage between the gas source 104 and the nozzle 108. The gas source 104 and the gas 110 within the gas source 104 are thereby in fluid communication with the nozzle 108 via the conduit 106. Figure 1 Also shown is an inductor 120 defining a container 122. In one implementation, the inductor 120 can be or include a smart inductor having a Curie temperature, wherein heating of the smart inductor decreases or stops when the smart inductor reaches the Curie temperature, even in the presence of a sustained magnetic flux field. In another implementation, the inductor 120 can be or include an inductor that does not have a Curie temperature but continues to heat in the presence of a sustained magnetic flux field, wherein the temperature of the inductor 120 can be controlled by cycling (i.e., energizing and de-energizing) an induction coil 140 (described below). The inductor 120 is configured to contain the material 102 to be heated within the container 122.

[0028] The gas 110 may be or include, for example, air or another gas or gases. In one implementation, the gas source 104 is a compressed gas cylinder that supplies the gas 110. In another implementation, the gas source 104 may be or include a blower, including, for example, a fan or a pump (not separately shown for simplicity), that directs and / or supplies ambient air to the conduit 106. In another implementation, the gas source 104 may be a compressor.

[0029] Figure 1 Also shown is a heat source 130 that heats the gas 110 as it flows through the conduit 106 before exiting the nozzle 108. Figure 1 As shown, heat source 130 may be or include a heating element, such as a resistive or inductive heating element, that encloses and / or covers conduit 106. During use, heat source 130 outputs thermal energy 132 that heats conduit 106 and, in turn, gas 110 flowing therethrough.

[0030] The system 100 further includes an induction coil 140 configured to generate a magnetic flux field 142 and to emit the magnetic flux field 142 onto the inductor 120. The induction coil 140 may be placed below a surface 144 of a support structure 146, wherein, during use, the inductor 120 rests on the surface 144. The conduit 106 and the nozzle 108 are made of a non-magnetic material such as copper or a heat-resistant synthetic material to prevent them from being heated by the induction coil 140.

[0031] In an exemplary method or process of using system 100, material 102 is placed into container 122, and nozzle 108 is positioned relative to material 102 so as to direct heated gas onto material 102 within container 122. Figure 1 The nozzle 108 is shown placed into the bulk of the material 102 (e.g., placed such that at least a portion of the nozzle 108 is placed below the upper surface of the bulk of the material 102 within the container 122), but it will be understood that the nozzle 108 may be placed in another position that directs the heated gas 110 onto the material 102. For example, the nozzle 108 may be placed above the material 102 such that the nozzle 108 directs the heated gas 110 downward onto and into the material 102. The position of the nozzle 108 may depend, at least in part, on the form of the material 102.

[0032] After the nozzle 108 is placed, the gas 110 is released from the gas source 104 into the conduit 106 at a desired gas flow rate. For example, the gas 110 may be released at a rate of approximately 0.01 cubic feet per minute (ft 3 / min) to about 10ft 3 / min, or about 0.10ft 3 / min to about 1.0ft 3 / min is released into the conduit 106. The gas flow rate can depend at least in part on different aspects of the design of the system 100, for example, on the size and configuration of the conduit 106 and the configuration and number of the nozzles 108. The gas 110 is heated as it passes through the portion of the conduit 106 heated by the heat source 130. In one implementation, the gas 110 can be heated to a temperature of from about 300°F to about 900°F, or from about 500°F to about 700°F. The temperature to which the gas 110 is heated can depend on, for example, the material 102 to be heated. After the gas 110 is heated, it continues through the conduit 106 to the nozzle 108. The gas 110 is directed by the nozzle 108 onto and / or into the material 102 (or otherwise engages the material 102), as shown. Figure 1 In FIG. 1 , the nozzle 108 includes a plurality of ports 150 from which the heated gas 110 is ejected from the nozzle 108 onto the material 102. The heated gas 110 ejected from the nozzle 108 onto the material 102 thereby heats the material 102.

[0033] During the heating of the material 102 by the heated gas 110 ejected from the nozzle 108, the induction coil 140 is activated (i.e., energized) to generate and emit a magnetic flux field 142 to engage the inductor 120. In this way, the material 102 is heated by both the inductor 120 and the heated gas 110 ejected from the nozzle 108. In addition, the material 102 is heated from at least two opposite directions (e.g., Figure 1 As shown, for example, heating is performed from the direction of the vertical side of the inductor 120 and from the opposite direction of the horizontal injection of the heated gas 110 from the port 150 of the nozzle 108. However, due to the high void volume and low thermal conductivity of some materials such as chopped prepreg, the heat provided to the material 102 via the heated gas 110 can more effectively quickly bring the material 102 to processing temperature than the heat provided by the inductor 120.

[0034] In some implementations, heating of the inductor 120 may be initiated by energizing the induction coil 140 at approximately the same time (e.g., simultaneously, within ±5 seconds, within ±10 seconds, etc.) as initiating the injection of the heated gas 110 from the nozzle 108. In the alternative, either the heating by the inductor 120 or the heating by the heated gas 110 may occur before the other (e.g., more than 10 seconds before the other), depending on individual process requirements.

[0035] In some processes, when the material 102 reaches the processing temperature, heat from both sources (i.e., heat provided by the inductor 120 and heat provided by the heated gas 110) can be removed from the material 102 at approximately the same time. In other processes, heat provided by one source can be removed before the other source is removed. For example, heat can be applied to the material 102 from both the inductor 120 and the nozzle 108 until the material 102 reaches a target temperature, such as a temperature below the processing temperature, at which point heat from one source (e.g., heat from the inductor 120 or the nozzle 108) can be removed while heat from the other source can continue to bring the material 102 to the processing temperature. For example, in applications where the processing temperature is the melting temperature of the material 102 (or a component thereof), it may be desirable to remove the nozzle 108 from the material 102 before the melting temperature is reached to prevent contamination or adhesion of the molten material to the nozzle 108. Therefore, in some processes, once the material 102 reaches a target temperature that is below the melting temperature of the material 102 or a component of the material 102, the nozzle 108 can be removed from the material 102. In such a process, the inductor 120 may provide the additional heating needed to bring the material 102 to the processing temperature without further heating the material 102 using the heated gas 110 .

[0036] In an exemplary implementation, the inductor 120 is a first inductor 120 that provides a first mold portion defining a first mold surface 160. In this implementation, as Figure 2 As shown, the system 100 also includes a second inductor 200 that provides a second mold portion defining a second mold surface 202. Figure 1 The configuration shown in is considered to illustrate the material heating phase of a process such as a molding process, then Figure 2 It can be considered to illustrate the forming stage, where the second mold part is moved into position or location to form a part, structure or component from the heated material. Figure 1 During the heating of the first inductor 120 in the material heating stage, the second inductor 200 may also be heated by the induction coil 140 or a separate induction coil (not shown separately for simplicity). Then, the second inductor 200 may be moved to Figure 2 Position shown.

[0037] like Figure 2 As shown, the nozzle 108 has been repositioned away from (e.g., removed from) the container 122, and the second mold portion 200 has been placed to engage the material 102 such that the second mold surface 202 physically contacts the material 102 such that the mold surfaces 160, 202 form a molded part from the material 102. Subsequently, the material 102 may be cooled, the second inductor 200 may be removed from the material 102, and the material 102 may be removed from the first inductor 120 to produce a molded part formed from the material 102. Figure 3It should be understood that the form of the molded component 300 is an example and other forms of the molded component 300 can be envisioned.

[0038] Figure 4 1 is a top view showing another implementation of a system 400 for heating a material 102 within an inductor 120 defining a container 122. The system 400 includes a gas 110 within a gas source 104, wherein the gas 110 and the gas source 104 are in fluid communication with a main conduit 402. The main conduit 402 is in fluid communication with a plurality of auxiliary conduits 404, which in turn are in fluid communication with a plurality of nozzles 406, which are or provide a plurality of gas injectors 404. The system 400 also includes an induction coil 408 configured to heat the inductor 120, and at least one heat source configured to heat the gas 110 before the gas 110 exits the plurality of nozzles 406. The heat source may include: a first heat source 410 that heats the main conduit 402 and the gas 110 as the gas 110 passes through the main conduit 402; a second heat source 412 that heats the plurality of auxiliary conduits 404 and the gas 110 as the gas 110 passes through the plurality of auxiliary conduits 404; or both the first heat source 410 and the second heat source 412.

[0039] Compared to a system including, for example, only a single nozzle, a system including multiple nozzles 406 Figure 4 The system 400 can provide more uniform heating of the material 102 over a larger area. Figure 4 A system 400 is shown that includes one primary conduit 402, three secondary conduits 404, and eight nozzles 406, although other configurations are also contemplated.

[0040] In use Figure 4 During operation of the system 400, the gas 110 may be released from the gas source 104 into the main conduit 402 using, for example, a valve 420. The gas enters the main conduit 402 from the gas source 104 and then enters the plurality of secondary conduits 404. The gas 110 may be heated by a first heat source 410 within the main conduit 402, by a second heat source 412 within the plurality of secondary conduits 404, or by both the first heat source 410 and the second heat source 412. The heated gas 110 then travels through the plurality of secondary conduits 404 and enters the plurality of nozzles 406 and then is directed onto and / or into the material 102 through the plurality of nozzles 406.

[0041] During the heating of the material 102 using the heated gas 110 ejected from the plurality of nozzles 406, the induction coil 408 is energized to emit a magnetic flux field 430 onto the inductor 120. The magnetic flux field 430 causes the inductor 120 to heat, thereby heating the material 102 together with the heated gas 110. In an exemplary process, once the material 102 reaches the first processing temperature, the flow of gas 110 from the gas source 110 may be stopped, heating of the conduits 402, 404 using the first and / or second heat sources 410, 412 may be stopped, and the plurality of nozzles 406 may be removed from the container 122. Additional heating of the material 102 may continue solely through the heating provided by the inductor 120. In another exemplary process, heating by both the heated gas 110 and the inductor 120 may be stopped simultaneously. In yet another exemplary process, heating of the material 102 using the inductor 120 may be stopped while heating of the material 102 using the heated gas 110 continues.

[0042] In general, in applications where a charge material, such as a large amount of chopped prepreg material, is placed on an induction heated inductor and heated only by the inductor, the inductor reaches the processing temperature more quickly than the charge material due, at least in part, to the low thermal conductivity of the material. This can result in processing delays due to the additional time required for the material to reach the processing temperature. According to implementations of the present disclosure, the heating rate of a material, such as a segmented or chopped prepreg, can be increased to more closely match the heating rate of the inductor, so that the material reaches the processing temperature in a shorter amount or duration, for example, at a heating rate that more closely matches the heating rate of the inductor. The target temperature can be a processing temperature that varies depending on the material and process. For example, the processing temperature can be lower than, equal to, or higher than the melting temperature of the material or material component.

[0043] Furthermore, with prior systems, the temperature of the heated material lags behind the temperature of the inductor. In contrast, with systems according to the present disclosure, the temperature of the heated material can match (or more closely match) the temperature of the inductor at any point in time during heating. For example, during heating, the average temperature of the material within the container provided by the inductor can be within ±90% or within ±20% of the temperature of the inductor or the mold surface defined by the inductor. This percentage can be determined at any point in time using the formula (T1-T2) / T1, where T1 is the temperature of the mold surface defined by the inductor and T2 is the temperature of the heated material.

[0044] For example, Figure 5 A first graph 500 may be included that may represent a heating profile for a system in which the material is heated only by an inductor, and a system according to an implementation of the present disclosure (i.e., a system in which the material is heated at least in part using a heated gas, such as Figure 15. A second graph 550 of a heating profile for a system shown in FIG. 500. The time and temperature scales of the graphs 500, 550 have been normalized relative to each other.

[0045] The first graph 500 includes a first heating profile (i.e., a first heating rate) 502 of an inductor (e.g., inductor 120) and a second heating profile (i.e., a second heating rate) 504 of a material (e.g., material 102, such as chopped or segmented prepreg) during heating by the inductor. As described above, in the first graph 500, the material is heated only by the inductor, where the inductor is heated using a magnetic flux field generated by an induction coil as described above. During heating, the heating profile 502 of the inductor causes the inductor to reach a target temperature 506 in less time than evidenced by the heating profile 504 of the material heated by the inductor. As shown in the first graph 500, the temperature of the heated material lags significantly behind the temperature of the inductor until the material reaches the target temperature 506.

[0046] Described another way, in the first graph 500, the first temperature profile 502 has a first duration, where the first duration begins when the induction coil is powered on at time=0 and ends when the inductor reaches the target temperature 506. The second temperature profile 504 has a second duration, where the second duration begins when the induction coil 140 is powered on at time=0 and ends when the material 102 reaches the target temperature 506. Thus, the second duration is significantly longer than the first duration.

[0047] In contrast, the second graph 550 includes a third heating profile (i.e., a third heating rate) 552 of the inductor (e.g., the inductor 120) and a fourth heating profile (i.e., a fourth heating rate) 554 of the material (e.g., the material 102, such as chopped or segmented prepreg) during inductor heating. In the second graph 550, the material is heated by the inductor and the heated gas delivered to and / or into the material using implementations of the present disclosure as described above, such as the systems 100, 400. During the heating of the material by both the inductor and the heated gas, the duration for both the inductor and the material to first reach the target temperature 506 is much shorter than that shown in the first graph 500. For example, the third heating rate 552 and the fourth heating rate 554 can raise the temperature of the material 102 (e.g., the molding material) and the inductor (e.g., the first mold surface defined by the inductor) to within 50°F of the processing temperature within a 300 second period of each other. As shown in the second graph 550, throughout the process of heating the material at any point in time up to the target temperature 506, the temperature of the material shown in the fourth profile 554 closely matches the temperature of the inductor shown in the third profile 552, with a variation of no more than ±25% or no more than ±10%. In the second graph 550, the heating of the inductor and the injection of the heated gas onto the material generally begin simultaneously (i.e., 5 seconds from each other). The structural and performance characteristics of the heating system can be adjusted as described below so that the heating rate and heating profile of the inductor (e.g., the mold portion and / or the mold surface defined by the mold portion) matches the heating rate and heating profile of the material (e.g., the charge).

[0048] Described in another way, in the second graph 550, the third temperature profile 552 has a third duration, where the third duration begins when the induction coil is powered on (as shown in the second graph 550, at time=0) and ends when the inductor reaches the target temperature 506. The fourth temperature profile 554 has a fourth duration, where the fourth duration begins when the heated gas is first directed to the material (as shown in the second graph 550, at time=0) and ends when the material 102 reaches the target temperature 506. Therefore, the third and fourth durations are approximately equal and can vary, such as less than 5 minutes, or less than 1 minute. In one implementation, the third duration and the fourth duration can be, for example, about 3.5 minutes to about 7.0 minutes. In addition, during the third duration and the fourth duration, the temperature of the inductor varies by no more than ±5%, or no more than ±0.5%, relative to the temperature of the material throughout the third duration and the fourth duration. It should be understood that although in the second curve 550, the coil is energized while the heated gas is ejected from the nozzle at t=0, in other processes, the induction coil can be energized before the heated gas is ejected from the nozzle, or the heated gas can be ejected from the nozzle before the induction coil is energized.

[0049] The first graph 500 shows that when the material is heated by the inductor alone, an extended period of time is required to heat the material to the target temperature 506. The second graph 550 shows that when the material is heated by both the inductor and the heated gas, a much shorter time is required to heat the material to the target temperature 506 compared to the first graph. Generally, analyzing the data obtained from the experiments, it has been found that heating the material with the inductor and the heated gas can be performed in half the time or less than half the time required to heat the material with the inductor alone. When the heated gas is introduced onto the charge, the charge heating rate can be about 5°F per minute (°F / min) to about 500°F / min, or about 100°F / min to about 200°F / min. In the second graph 550, the heating rate 554 of the charge from time = 0 to the charge temperature reaching the target temperature 506 is about 77°F / min, which results in the charge reaching the target temperature 750°F in less than 10 minutes. During the molding process, depending on the system design, the time required for the inductor (e.g., the first mold portion) to reach the target temperature may be longer or shorter than the time required for the charge to reach the target temperature. In some processes, it may be desirable to adjust the heating rate and heating profile of the charge so that the charge and the inductor (e.g., the first mold portion) reach the target temperature at the same time or approximately at the same time (e.g., within one minute of each other, or within five minutes of each other), as shown in the second graph 550. Matching the heating profile (heating rate) of the charge with the heating profile (heating rate) of the inductor ensures that, for example, the mold surface defined by the inductor reaches the target temperature at the same time or approximately at the same time as the charge, and does so with the same heating profile or approximately the same heating profile. This can be accomplished, for example, by adjusting (i.e., raising or lowering) the maximum temperature of the heated gas flowing through the nozzle, changing (i.e., increasing or decreasing) the number of nozzles in the system, changing the size and / or number of slits in the nozzle, changing the pressure or flow of the gas in the conduit, adjusting the power applied to the induction coil, a combination of these factors, or by changing or adjusting another related factor, as will be apparent to one of ordinary skill in the art. In some implementations, the heating rate and distribution of the inductor (i.e., the mold portion and / or mold face defined by the inductor) and the charge can be monitored during heating. Various system parameters (e.g., temperature and flow rate of the heating gas) can be adjusted in situ to adjust the heating rate and distribution of the charge so that they match the heating rate and distribution of the inductor.

[0050] Figure 6 A method 600 for heating a material is shown. The method 600 may be performed by operating or using the above Figures 1 to 4, and therefore described with reference to these figures. However, it should be understood that method 600 is not limited to any specific structure or purpose, unless explicitly stated herein. Method 600 can be performed before, during or after other processes, for example as an assembly subprocess. It should be understood that although the process is described as a series of actions or events, the present disclosure is not limited to the order of such actions or events. Some actions may occur in different orders and / or occur simultaneously with other actions or events other than those described herein. In addition, the method according to the present disclosure may include other actions or events not shown for simplicity, and one or more actions or events shown may be removed or modified.

[0051] At 602, a material 102, such as a prepreg, is placed within a container 122 of an inductor assembly 100, 400, wherein the container 122 may be provided, for example, by an inductor 120. The method 600 also includes, at 604, heating the inductor 120 of the inductor assembly 100, 400 with a magnetic flux field 142, 430 emitted by an induction coil 140. During and / or after the heating of the inductor 120, thermal energy from the inductor 120 may be transferred to the material 102 within the container 122. At 606, the material 102 within the container 122 is heated with a heated gas 110 directed to the material 102 by a nozzle 108, 406 of a gas injector 106, 404. Subsequently, the heating of the material 102 within the container 122 by the heated gas 110 is stopped, as at 608. The method 600 also includes stopping the heating of the inductor 120 by the magnetic flux field 142, 430, as at 610. Stopping the heating of the inductor 120 at 610 may be performed before, after, or simultaneously with stopping the heating of the material 102 at 608. At 612, the method 600 further includes removing the material 102 from the container 122 provided by the inductor 120. The removal at 612 may be performed, for example, before or after cooling the material 102 within the container 122.

[0052] The present disclosure includes embodiments according to the following items:

[0053] Item 1. A method (600) for heating a material (102), comprising:

[0054] placing a material (102) in a container (122) of an inductor assembly;

[0055] heating an inductor (120) of an inductor assembly (100, 400) using a magnetic flux field (142, 430) emitted by an induction coil (140, 408); and

[0056] The material (102) is heated with a heated gas (110) directed to engage the material (102) within the container (122).

[0057] Item 2. The method (600) according to Item 1, further comprising:

[0058] allowing gas (110) to flow from a gas source (104) into a conduit (106) in fluid communication with the gas source (104); and

[0059] heating the gas (110) in the conduit (106) to form heated gas (110);

[0060] Wherein, heating the material (102) further comprises spraying heated gas (110) from the conduit (106) through the nozzle (108, 406) to join the material (102).

[0061] Item 3. The method (600) of Item 2, wherein:

[0062] The material (102) is a quantity of the material (102) in particulate form; and

[0063] Heating the material (102) also includes placing the nozzle (108, 406) into the container (122) and into a quantity of the material (102) prior to heating the material (102) with the heated gas (110).

[0064] Item 4. The method (600) of any one of items 1-3, wherein the material (102) has a processing temperature, and the method (600) further comprises:

[0065] ceasing to heat the material (102) with the heated gas (110) before the material (102) reaches a processing temperature; and

[0066] After the heating of the material (102) by the heating gas (110) is stopped, the material (102) is further heated to a processing temperature using heat transferred to the material (102) from the inductor (120).

[0067] Item 5. The method (600) of any one of items 1-3, wherein the material (102) has a processing temperature and the inductor (120) includes a die face (160, 202) in thermal communication with the material (102); and wherein the method (600) further includes:

[0068] heating the material (102) at a first heating rate (552) and heating the mold surface (160, 202) at a second heating rate (554);

[0069] wherein the first heating rate and the second heating rate (552, 554) raise the temperature of the mold face (160, 202) and the material (102) to within 5°F of the processing temperature within a 300 second period of each other.

[0070] Item 6. The method (600) of Item 5, wherein:

[0071] The heating of the mold surface (160, 202) has a first temperature profile for a first duration, and the first duration begins when the magnetic flux field (142, 430) is first directed at the inductor (120) and ends when the material (102) reaches a processing temperature;

[0072] The heating of the material (102) has a second temperature profile for a second duration, and the second duration begins when the heated gas (110) is first directed to the material (102) and ends when the material (102) reaches a processing temperature;

[0073] The first duration begins simultaneously with the second duration; and

[0074] The first temperature profile does not vary by more than 20° F. relative to the second temperature profile over the first duration and the second duration.

[0075] Item 7. The method (600) of any one of Items 1-6, further comprising heating a material (102) within a container (122) of the inductor assembly (100, 400) using an inductor (120) of the inductor assembly (100, 400).

[0076] Item 8. The method (600) of any one of Items 1-7, wherein the inductor (120) defines at least a portion of the first mold surface (160), and the method (600) further comprises:

[0077] heating the second mold surface (202) using a magnetic flux field (142, 430) emitted by an induction coil (140, 408);

[0078] before the material (102) reaches a processing temperature of the material (102), stopping heating the material (102) with the heating gas (110);

[0079] After stopping the heating of the material (102) with the heated gas (110), heating the material (102) in the container (122) to a processing temperature using heat transferred to the material (102) from the inductor (120); and

[0080] The material (102) is engaged with the second mold surface (202).

[0081] Item 9. The method (600) of any one of Items 1-8, further comprising heating the inductor (120) to a Curie temperature at which the inductor (120) changes from magnetic to non-magnetic.

[0082] Item 10. A molding process comprising:

[0083] A molding material (102) having a processing temperature is placed in a container (122) defined by the inductor assembly (100, 400), wherein:

[0084] The sensor assembly (100, 400) includes a sensor (120);

[0085] The inductor (120) defines a mold surface (160, 202); and

[0086] The mold surface (160, 202) is in thermal communication with the molding material (102);

[0087] heating the molding material (102) at a first heating rate (552) using a heated gas (110) directed to the molding material (102); and

[0088] heating the mold surface (160, 202) at a second heating rate (554) by directing a magnetic flux field (142, 430) toward the inductor (120);

[0089] Wherein the first heating rate and the second heating rate (554) raise the temperature of the molding material (102) and the mold surface (160, 202) to within 5°F of the processing temperature within a 300 second period of each other.

[0090] Item 11. The molding process of Item 10, wherein:

[0091] Heating the mold surface (160, 202) has a first temperature profile for a first duration, wherein the first duration begins when the magnetic flux field (142, 430) is first directed at the inductor (120) and ends when the molded material (102) reaches a processing temperature;

[0092] Heating the molding material (102) has a second temperature profile over a second duration, wherein the second duration begins when the heating gas (110) is first directed to the molding material (102) and ends when the molding material (102) reaches a processing temperature;

[0093] The first duration begins simultaneously with the second duration; and

[0094] The first temperature profile differs from the second temperature profile by no more than 20° over the first duration and the second duration.

[0095] Item 12. The molding process of Item 11, wherein the first duration and the second duration are from 3.5 minutes to 7.0 minutes.

[0096] Item 13. The molding process according to any one of Items 10-12, further comprising:

[0097] allowing gas (110) to flow from a gas source (104) into a conduit (106); and

[0098] heating the gas (110) in the conduit (106) to form heated gas (110);

[0099] The heating of the material (102) includes injecting a heated gas (110) through a nozzle (108, 406) to bond the material (102).

[0100] Item 14. The molding process of Item 13, wherein:

[0101] The molding material (102) is a quantity of the molding material (102) in the form of particles; and

[0102] Heating of the material (102) includes placing a nozzle (108, 406) into a container (122) and into a quantity of molding material (102) prior to heating the molding material (102) with a heated gas (110).

[0103] Item 15. The molding process of any of Items 10-14, wherein the first heating rate (552) and the second heating rate (554) are between 100°F / minute (°F / min) and 200°F / min.

[0104] Item 16. The molding process of any one of Items 10-15, further comprising ceasing to heat the molding material (102) with the heated gas (110) when the processing temperature is ±25°F.

[0105] Item 17. A system (100, 400) for heating a molding material (102), comprising:

[0106] An inductor assembly (100, 400) comprising an inductor (120), wherein:

[0107] The inductor (120) defines a container (122) configured to contain a molding material (102); and

[0108] The inductor (120) further defines a mold surface (160, 202); and

[0109] A gas (110) injector is configured to direct heated gas (110) toward a molding material (102) disposed within a container (122).

[0110] Item 18. The system (100, 400) of Item 17, wherein:

[0111] The gas (110) ejector includes a nozzle (108, 406) and a conduit (106) in fluid communication with the nozzle (108, 406);

[0112] The nozzle (108, 406) is configured to direct the directed heated gas (110) from the conduit (106) toward the molding material (102); and

[0113] The system (100, 400) also includes a heat source (130) configured to heat the gas (110) within the conduit (106).

[0114] Item 19. The system (100, 400) of Item 18 further comprises a plurality of gas (110) injectors, each gas injector comprising a nozzle (108, 406) and a conduit (106) fluidically connected to the nozzle (108, 406), wherein the nozzle (108, 406) of each of the plurality of gas (110) injectors is configured to direct the heated gas (110) toward the molding material (102).

[0115] Item 20. The system (100, 400) of any one of Items 17-19, further comprising an induction coil (140, 408) configured to emit a magnetic flux field (142, 430) toward the inductor (120).

[0116] Item 21. The system (100, 400) of any one of Items 17-20, wherein the inductor (120) comprises a Curie temperature at which the inductor (120) transitions from magnetic to non-magnetic.

[0117] Item 22. The system (100, 400) of Item 21, wherein the gas (110) ejector is non-magnetic.

[0118] All ranges disclosed herein are understood to encompass any and all subranges included therein. For example, a range of "less than 10" may include any and all subranges between a minimum value of 0 and a maximum value of 10 (and including a minimum value of 0 and a maximum value of 10), that is, any and all subranges with a minimum value equal to or greater than 0 and a maximum value equal to or less than 10, such as 1 to 5. In some cases, the numerical values ​​described for the parameters may be negative. In this case, the example values ​​of the range of "less than 10" may be assumed to be negative values, such as -1, -2, -3, -10, -20, -30, etc.

[0119] Although the present disclosure has been shown with respect to one or more implementations, the examples shown may be changed and / or modified without departing from the spirit and scope of the appended claims. For example, it should be understood that although the process is described as a series of actions or events, the present disclosure is not limited by the order of such actions or events. Some actions may occur in different orders and / or occur simultaneously with other actions or events other than those described herein. Moreover, all process stages may not be required to implement the method according to one or more aspects or implementations of the present disclosure. It should be understood that structural components and / or process stages may be added, or existing structural components and / or process stages may be removed or modified. In addition, one or more actions described herein may be performed in one or more separate actions and / or stages. In addition, the terms "including", "includes", "having", "has", "with", or variations thereof are used in the specific embodiments and claims, and these terms are intended to be inclusive in a manner similar to the term "comprising". The term "at least one of..." is used to indicate that one or more of the listed items can be selected. As used herein, the term "one or more of" with respect to a list of items such as A and B means A alone, B alone, or A and B. In addition, in the discussion and claims herein, the terms "on", "on the other", used with respect to two materials, means at least some contact between the materials, while "over" means that the materials are adjacent, but may have one or more additional intervening materials, so that contact is possible but not required. Neither "on" nor "over" implies any directionality as used herein. The term "conformal" describes a coating material in which the angle of the underlying material is maintained by the conformal material. The term "about" means that the listed values ​​can be slightly changed, as long as the change does not cause the process or structure to not conform to the implementation shown. Finally, "exemplary" indicates that the description is used as an example, rather than implying that it is ideal. Other implementations of the present disclosure will be apparent to those skilled in the art by considering the present specification and the practice disclosed herein. The present specification and examples are to be considered exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

[0120] The terms of relative position used in this application are defined based on a plane parallel to the conventional plane or working surface of the workpiece, regardless of the orientation of the workpiece. The terms "horizontal" or "lateral" used in this application are defined as a plane parallel to the conventional plane or working surface of the workpiece, regardless of the orientation of the workpiece. The term "vertical" refers to a direction perpendicular to the horizontal. Terms such as "upper", "side", "higher", "lower", "above", "top" and "below" are defined relative to the conventional plane or working surface on the top surface of the workpiece, regardless of the orientation of the workpiece.

Claims

1. A method for heating a material, comprising: placing a molding material within a container of the inductor assembly; an inductor for heating the inductor assembly using a magnetic flux field emitted by the induction coil; placing a gas injector including a nozzle into the container to direct heated gas into the molding material located in the container; as well as The molding material is heated with heated gas directed to the molding material within the container.

2. The method according to claim 1, further comprising: allowing gas to flow from a gas source into a conduit in fluid communication with the gas source; as well as heating the gas within the conduit to form the heated gas; Wherein, heating the molding material further comprises ejecting the heated gas from the conduit through the nozzle to engage the molding material.

3. The method according to claim 2, wherein: The molding material is a quantity of molding material in the form of particles; and Heating the molding material further includes placing the nozzle into the container and into a quantity of the molding material prior to heating the molding material with the heated gas.

4. The method according to any one of claims 1 to 3, wherein: The molding material has a processing temperature, and the method further comprises: stopping heating the molding material with the heating gas before the molding material reaches the processing temperature; and After the heating of the molding material by the heating gas is stopped, the molding material is further heated to the processing temperature using the heat transferred from the inductor to the molding material.

5. The method of claim 1, further comprising heating the molding material within the container of the inductor assembly with the inductor of the inductor assembly.

6. The method according to claim 1, wherein: The inductor defines at least a portion of a first mold surface, and the method further comprises: heating a second mold surface using the magnetic flux field emitted by the induction coil; before the molding material reaches a processing temperature of the molding material, stopping heating the molding material with the heating gas; After stopping heating the molding material with the heating gas, heating the molding material in the container to the processing temperature using heat transferred from the inductor to the molding material; and The molding material is engaged with the second mold surface.

7. The method of claim 1 further comprising heating the inductor to a Curie temperature at which the inductor transitions from magnetic to non-magnetic.

8. A molding process comprising: A molding material at a processing temperature is placed in a container defined by the inductor assembly, wherein: The sensor assembly includes a sensor; The inductor defines a mold surface; and The mold surface is in thermal communication with the molding material; placing a nozzle into the container and placing a certain amount of the molding material therein; heating the molding material at a first heating rate with heated gas directed to the molding material; and heating the mold surface at a second heating rate by directing a magnetic flux field at the inductor; Wherein the first heating rate and the second heating rate raise the temperature of the molding material and the mold surface to within 5°F of the processing temperature within 300 seconds of each other.

9. The molding process according to claim 8, wherein: the heating of the mold surface having a first temperature profile over a first duration, wherein the first duration begins when the magnetic flux field is first directed at the inductor and ends when the molding material reaches the processing temperature; the heating of the molding material having a second temperature profile over a second duration, wherein the second duration begins when the heating gas is first directed to the molding material and ends when the molding material reaches the processing temperature; The first duration begins simultaneously with the second duration; and The first temperature profile does not vary by more than 20° relative to the second temperature profile over the first duration and the second duration.

10. The molding process according to claim 9, wherein: The first duration and the second duration are 3.5 minutes to 7.0 minutes.

11. The molding process according to claim 8, further comprising: allowing gas to flow from a gas source into the conduit; as well as heating the gas within the conduit to form the heated gas; Wherein, the heating of the molding material includes injecting the heated gas through the nozzle to engage the molding material.

12. The molding process of claim 11, wherein: The molding material is a quantity of molding material in the form of particles; and The heating of the molding material includes placing the nozzle into the container and into a quantity of the molding material before heating the molding material with the heated gas.

13. A molding process according to any one of claims 8 to 12, wherein: The first heating rate and the second heating rate are between 100°F / minute and 200°F / minute.

14. The molding process of any one of claims 8-12, further comprising ceasing to heat the molding material with the heated gas when the processing temperature is within ±25°F.

15. A system for heating a molding material, comprising: A sensor assembly, comprising a sensor, wherein: The inductor defines a container configured to contain the molding material; as well as The inductor further defines a mold surface; as well as A gas injector includes a nozzle configured to be positioned within the container and configured to direct heated gas toward a molding material disposed within the container.

16. The system of claim 15, wherein: The gas injector further includes a conduit in fluid communication with the nozzle; and The system also includes a heat source configured to heat the gas within the conduit.

17. The system of claim 16, further comprising a plurality of gas injectors, each gas injector comprising a nozzle and a conduit in fluid communication with the nozzle, wherein The nozzle of each of the plurality of gas injectors is configured to direct the heated gas toward the molding material.

18. The system of any one of claims 15-17, further comprising an induction coil configured to emit a magnetic flux field toward the inductor.

19. The system of claim 18, wherein: The inductor includes a Curie temperature at which the inductor transitions from magnetic to non-magnetic.

20. The system of claim 19, wherein: The gas injector is non-magnetic.

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