Consumable pretreatment device for 3D printer

Abstract

The invention belongs to the technical field of additive manufacturing, and particularly relates to a consumable pretreatment device for a 3D printer, which is mounted on a body frame of the 3D printer and comprises a shell, a guide pipe, a heating assembly, a first heating chamber, a second heating chamber, a temperature detection element and a control assembly. Before entering the spray head, the consumables sequentially pass through different heating cavities through the guide pipe to be preheated in a low-temperature, constant-temperature and gradual mode, the control assembly conducts closed-loop control on the heating assembly according to temperature detection signals, and the consumables are kept in a pretreatment interval lower than the glass-transition temperature. The initial temperature of consumables entering the spray head can be increased, extrusion resistance is reduced, advanced softening or clamping stagnation of the consumables is avoided, the stability and forming quality of the 3D printing process in the low-temperature environment are improved, the structure is compact, and an existing 3D printer can be conveniently modified and installed.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, specifically relating to a consumable pretreatment device for 3D printers, and more particularly to a consumable pretreatment device set on the consumable conveying path for low-temperature constant-temperature preheating and state control of the consumable before it enters the nozzle, applicable to fused deposition modeling or fused filament modeling 3D printing equipment. Background Technology

[0002] With the continuous development of 3D printing technology, especially fused deposition modeling (FDM) technology, it has been widely used in industrial manufacturing, education, medical modeling, and personalized product manufacturing. FDM 3D printers typically use thermoplastic filaments as printing materials. The filaments are continuously fed into the nozzle through a feeding mechanism. Under the heating action of the nozzle, the filaments melt and are extruded through the nozzle, stacking layer by layer to form a three-dimensional solid structure.

[0003] In existing technologies, the heating system of 3D printers is mainly concentrated inside the nozzle, relying on a finite-length melting zone within the nozzle to rapidly heat and melt the incoming filament. This structure can generally meet basic printing needs under conditions of moderate ambient temperature, small filament diameter, and low printing speed. However, in practical applications, especially in winter or low-temperature working conditions, the initial temperature of the filament before entering the nozzle is low. The nozzle needs to complete the heating and melting process of the filament in a very short time, thus significantly increasing the thermal load and extrusion load of the nozzle.

[0004] The aforementioned problems are particularly pronounced when using larger diameter filaments (e.g., 2.85 mm or 3.0 mm filaments). Due to the larger volume per unit length and stronger thermal inertia of larger diameter filaments, their internal temperature rises relatively slowly. This can easily lead to insufficient melting or uneven melting within the limited melting zone of the printhead, resulting in increased extrusion resistance, unstable material output, under-extrusion, decreased interlayer bonding, and even malfunctions such as material slippage, material biting, or printhead clogging. These issues severely affect print quality and the stability of equipment operation.

[0005] To address these issues, some existing technologies attempt to improve the overall thermal environment by increasing printhead temperature, reducing printing speed, or using a closed printing chamber. Other solutions involve external filament drying boxes or heating chambers to heat and dry the filaments as a whole. However, most of these solutions suffer from insufficient specificity or new technical problems. For example, simply increasing printhead temperature can easily lead to material thermal degradation and increased stringing; closed printing chambers have limited effect on improving the temperature of the filaments at the printhead tip; and overall heating filament heating boxes or drying devices typically have large heating volumes and slow response times, making it difficult to accurately control the state of the filaments before they enter the printhead. Furthermore, improper temperature control can easily cause premature softening and deformation of the filaments, affecting feeding accuracy and even causing jamming.

[0006] Chinese utility model patent CN214820940U discloses a filament pretreatment device for 3D printers. This device heats a slitting blade using an eddy current coil, and a motor pushes the filament against the slitting blade via an active and driven pressure roller. This initially softens the filament and divides it into multiple lines, facilitating subsequent heating and melting and improving the uniformity of the melt. However, in practical applications, the filament is prone to breakage during slitting, and the heating effect needs improvement.

[0007] In addition, most existing consumable heating or pretreatment devices adopt a single-area heating method and lack a gradual temperature control structure along the consumable conveying direction. This makes it difficult to improve the initial temperature of the consumable while ensuring feeding stability and structural reliability. At the same time, most devices do not fully consider the impact of different consumable materials, different diameter specifications, and changes in ambient temperature on the pretreatment process. They lack effective temperature feedback and anti-softening limiting mechanisms, which limits their applicability and actual effect.

[0008] Therefore, how to provide a pretreatment device that can preheat the consumables at low temperature, in a controllable and gradual manner before they enter the printhead without changing the existing printhead structure and printing process, so as to increase the initial temperature of the consumables, reduce the printhead melt load and extrusion resistance, and prevent the consumables from softening, deforming or becoming unstable in the feed, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0009] To address the aforementioned shortcomings of existing technologies, this invention aims to solve the problem of fused deposition modeling (FDM) 3D printers where, in low-temperature environments or winter conditions, the initial temperature of the filament entering the nozzle is low. This is especially true when using thicker filaments, which can easily lead to insufficient melting, increased extrusion resistance, unstable material output, feeding slippage, and even nozzle clogging. Furthermore, existing filament heating or pretreatment methods suffer from drawbacks such as crude heating methods, slow response speeds, premature softening and deformation of the filament, and poor feeding stability. The purpose of this invention is to provide a filament pretreatment device for 3D printers. Without altering the existing nozzle structure and basic printing process, this device performs low-temperature, constant-temperature, and gradual preheating treatment on the filament before it enters the nozzle. This increases the initial temperature of the filament, reduces the melt load and extrusion resistance of the nozzle, and effectively prevents premature softening, bending, or jamming of the filament during pretreatment. This improves the stability and quality of the 3D printing process and enhances the device's adaptability to different filament materials, diameters, and environmental temperature variations.

[0010] To achieve the above objectives, the invention adopts the following technical solution: a consumable pretreatment device for a 3D printer, comprising a housing, a guide tube, a first heating chamber, a second heating chamber, a heating assembly, a temperature detection element, and a control assembly.

[0011] The housing is mounted on the machine frame. A guide tube and heating components are installed inside the housing. The housing has a slender structure along the filament conveying direction, and its interior forms a straight channel for the filament to pass through. The filament spool is fed into the 3D printer's nozzle through the guide tube.

[0012] The guide tube is disposed within the straight channel to axially guide and support the passing filamentous consumables. The guide tube is made of a heat-resistant, low-friction material and can be replaced with different specifications. The guide tube is installed within a support protective cover. Using similar materials can reduce the transport resistance of the consumables during the pretreatment process.

[0013] The heating component is disposed inside the housing and covers the supporting protective cover, and is used to heat the consumables inside the guide tube;

[0014] Temperature sensing elements are used to detect the temperature status in the first heating chamber and the second heating chamber, respectively.

[0015] An external sleeve is installed on the housing, allowing for quick replacement of the guide tube or rapid installation and maintenance of the heating components and support protective cover by disassembling the external sleeve.

[0016] The first heating chamber and the second heating chamber are disposed within the space formed by the outer cylinder and the shell. The outer cylinder and the shell are filled with thermal insulation material. The heating temperature of the second heating chamber is higher than that of the first heating chamber.

[0017] The control component is electrically connected to the heating component and the temperature detection component, and is used to control the heating components of the first heating chamber and the second heating chamber according to the detected temperature signal, so that the consumables passing through the pretreatment device are maintained within a preset low temperature constant temperature range.

[0018] According to another embodiment of the invention or any of the foregoing embodiments, a filament pretreatment device for a 3D printer is provided, wherein the housing is a box type, comprising two detachable parts, which are fixed to the outside of the machine frame by welding or bolts. Installed on the outside of the machine frame, it facilitates the modification of existing 3D printers without occupying or interfering with the internal space and structure of the 3D printer.

[0019] According to another embodiment of the invention or any of the foregoing embodiments, a consumable pretreatment device for a 3D printer is provided, wherein the housing is made of stainless steel, aluminum alloy or heat-resistant engineering plastic.

[0020] According to another embodiment of the invention or any of the foregoing embodiments, a consumable pretreatment device for a 3D printer is provided, wherein the guide tube is made of polytetrafluoroethylene or polyetheretherketone.

[0021] According to another embodiment of the invention or any of the foregoing embodiments, a consumable pretreatment device for a 3D printer is provided, wherein the insulation material is at least one of the following: glass fiber cotton, ceramic fiber cotton, or aluminum silicate fiber cotton.

[0022] According to another embodiment of the invention or any of the foregoing embodiments, a consumable pretreatment apparatus for a 3D printer is provided, wherein the heating component includes a flexible resistance heating element electrically connected to a control component to achieve closed-loop control of the pretreatment temperature.

[0023] According to another embodiment of the invention or any of the foregoing embodiments, a consumable pretreatment device for a 3D printer is provided, wherein the supporting protective cover extends out of the housing and has a single or multi-segment structure, made of a metal tube.

[0024] According to another embodiment of the invention or any of the foregoing embodiments, a filament pretreatment apparatus for a 3D printer is provided, wherein the control component is configured to set a corresponding target preheating temperature based on the filament material type, filament diameter specification and / or ambient temperature parameters, and to implement closed-loop temperature control for each heating zone, so that the pretreatment temperature of the filament is lower than its glass transition temperature, thereby avoiding significant softening of the filament.

[0025] The beneficial effects of this invention are:

[0026] 1. This invention preheats the filament at a low temperature and constant temperature before it enters the printhead, increasing the initial temperature of the filament and fully utilizing the effective melting zone inside the printhead. This reduces the printhead's melt load and extrusion resistance, improving material output stability. The axial progressive heating method ensures a smooth temperature change of the filament along the conveying direction, avoiding uneven melting caused by sudden temperature rises. This is beneficial for improving interlayer bonding, enhancing the surface quality and mechanical properties of the product, and improving printing quality and molding consistency.

[0027] 2. This invention controls the preheating temperature below the glass transition temperature of the consumable and uses a polyetheretherketone (PEEK) guide tube to axially guide and support the passing filamentous consumable, reducing the conveying resistance of the consumable during the pretreatment process. While increasing the temperature of the consumable, it maintains its axial rigidity, significantly reducing the risk of bending, jamming, and slippage.

[0028] 3. This invention employs independent control of multiple heating zones and a closed-loop temperature control method, which can be adjusted according to different consumable materials, diameters, and ambient temperatures. It is particularly suitable for printing scenarios involving low-temperature environments and large-diameter consumables. This invention can be directly integrated into the consumable delivery path of existing 3D printers without modifying the nozzle structure. Its modular design facilitates installation, replacement, and maintenance, and has significant engineering application value. Attached Figure Description

[0029] Figure 1 This is a three-dimensional schematic diagram of a 3D printer containing the consumable pretreatment device for a 3D printer as described in the invention.

[0030] Figure 2 This is a side view of the 3D printer in which the consumable pretreatment device for the 3D printer described in the invention is located.

[0031] Figure 3 A three-dimensional schematic diagram of the consumable pretreatment device for a 3D printer as described in the invention. Figure 1 ;

[0032] Figure 4 A three-dimensional schematic diagram of the consumable pretreatment device for a 3D printer as described in the invention. Figure 2 ;

[0033] Figure 5 This is a cross-sectional schematic diagram of the consumable pretreatment device for a 3D printer as described in the invention.

[0034] In the diagram: 1. Body frame; 2. Nozzle; 3. Consumable roll; 4. Insulation material; 5. Support and protective cover; 6. External tube; 7. Shell; 8. First heating chamber; 9. Second heating chamber; 10. Guide tube. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In this embodiment, a filament pretreatment device for a 3D printer is provided. The device is installed outside the frame 1 of a fused deposition modeling 3D printer and is used to preheat the filament before it enters the nozzle 2.

[0037] like Figure 5 As shown, the consumable pretreatment device includes a housing 7, a guide tube 10, a first heating chamber 9, a second heating chamber 11, a heating component, a temperature detection element, and a control component.

[0038] like Figure 1 , 2 As shown in Figure 5, the housing 7 is fixedly mounted on the frame 1 of the 3D printer, and the housing 7 is arranged in a slender structure along the filament conveying direction. A through channel is formed inside the housing 7 for the filament to pass through axially. The filament is pulled by the filament roll 3 through the feeding mechanism, passes through the through channel in sequence, and finally enters the nozzle 2 of the 3D printer.

[0039] like Figure 3 , 5 As shown, the guide tube 10 is disposed in a straight channel inside the housing 7. The guide tube 10 is arranged along the consumable conveying direction, with its two ends corresponding to the feed end and discharge end of the housing 7, respectively. The guide tube 10 is used to axially guide and support the passing filamentous consumables to ensure that the consumables maintain a basically straight state when passing through the pretreatment device. The guide tube 10 is made of heat-resistant, low-friction material and is designed as a replaceable structure according to the diameter specifications of the consumables. Guide tubes 10 with different inner diameter specifications can be installed in the housing 7 by disassembly and assembly to adapt to the use requirements of consumables with different diameters. A support protective cover 5 is sleeved on the outside of the guide tube 10, and the guide tube 10 is installed inside the support protective cover 5.

[0040] like Figure 4 , 5 As shown, the heating component is disposed within the housing 7 and arranged to surround the supporting protective cover 5. The heating component and the supporting protective cover 5 maintain indirect contact or contact, allowing heat to be transferred through the supporting protective cover 5 to the guide tube 10, thereby heating the consumables passing through the guide tube 10. With this arrangement, the consumables do not directly contact the heating element during pretreatment.

[0041] like Figure 3 ,4 As shown, an outer sleeve 6 is provided on the housing 7, forming a detachable connection structure between the outer sleeve 6 and the housing 7. By disassembling the outer sleeve 6, the guide tube 10, the support protective cover 5, and the heating assembly can be quickly installed, replaced, or maintained. The internal space enclosed by the outer sleeve 6 and the housing 7 is divided into a first heating chamber 9 and a second heating chamber 11 along the consumable conveying direction. The first heating chamber 9 is located near the feed end, and the second heating chamber 11 is located near the discharge end. The heating temperature of the second heating chamber 11 is set higher than that of the first heating chamber 9.

[0042] like Figure 5 As shown, both the first heating chamber 9 and the second heating chamber 11 are filled with insulation material 4. The insulation material 4 fills the space between the outer cylinder 6 and the shell 7 to reduce heat loss within the heating chamber. The insulation material 4 can be at least one of glass fiber cotton, ceramic fiber cotton, or aluminosilicate fiber cotton.

[0043] Temperature sensing elements are respectively disposed in the first heating chamber 9 and the second heating chamber 11, and are used to detect the temperature status in the corresponding heating chamber. The detection signal output terminal of the temperature sensing element is electrically connected to the control component.

[0044] The control component is electrically connected to the heating component and the temperature sensing element. Based on the temperature signal fed back by the temperature sensing element, the control component controls the heating components located in the first heating chamber 9 and the second heating chamber 11, maintaining each heating chamber within a preset temperature range. The control component is configured to set a target preheating temperature based on the material type, diameter, and / or ambient temperature parameters of the filament, ensuring that the temperature of the filament passing through the pretreatment device is below its glass transition temperature. The control component includes a button unit located outside the pretreatment device, used to receive user-inputted target preheating temperature commands. The control component performs closed-loop control of the heating components based on the target preheating temperature. The control component can also communicate with the main control system of the 3D printer to receive control commands sent by the main control system and control the heating components accordingly.

[0045] In this embodiment, the housing 7 is a box-type structure, comprising two detachable parts, which are fixed to the outside of the machine frame 1 by welding or bolting. This arrangement facilitates the modification and installation of existing 3D printers without occupying or interfering with the internal space structure of the 3D printer.

[0046] The housing 7 may be made of stainless steel, aluminum alloy, or heat-resistant engineering plastic. The guide tube 10 may be made of polytetrafluoroethylene or polyetheretherketone. The heating assembly includes a flexible resistance heating element, which is electrically connected to the control assembly to achieve closed-loop control of the temperature of the first heating chamber 9 and the second heating chamber 11.

[0047] like Figure 3 , 4 As shown, at least one end of the supporting protective cover 5 protrudes from the housing 7. The supporting protective cover 5 can be configured as a single-segment structure or a multi-segment splicing structure. The supporting protective cover 5 is made of a metal tube.

[0048] Working principle of the invention:

[0049] During the operation of the 3D printer, the filament is drawn by the filament roll 3 through the feeding mechanism and first enters the filament pretreatment device of this invention. After entering the device, the filament is axially guided and supported by the guide tube 10 located inside the housing 7. The guide tube 10 is made of low-friction, heat-resistant material, which keeps the filament in a straight conveying state throughout the entire process of passing through the pretreatment device, reducing frictional resistance with structural components and avoiding feeding instability caused by bending, shaking, or deviation.

[0050] The consumable material passes sequentially through the first heating chamber 9 and the second heating chamber 11 along the conveying direction within the guide tube 10. Heating components in each heating chamber indirectly heat the guide tube 10 and the consumable material inside, gradually increasing the overall temperature of the consumable material through conduction and convection. The first heating chamber 9 is used for initial preheating of the low-temperature consumable material, causing its temperature to rise steadily from ambient temperature to a preset initial preheating range. The second heating chamber 11 further compensates for the heating in the first heating chamber 9, ensuring that the consumable material reaches a more stable and uniform target pretreatment temperature before entering the nozzle 2. This axially progressive heating method effectively avoids sudden temperature changes in the consumable material over a short distance, thus preventing localized softening or structural instability.

[0051] During the heating process, temperature sensing elements arranged in each heating chamber collect chamber temperature information in real time and transmit the detection signals to the control component. The control component performs closed-loop regulation of the heating component according to the pre-set consumable material type, consumable diameter specifications, and ambient temperature parameters, so that the first heating chamber 9 and the second heating chamber 11 are always maintained in a constant temperature range below the glass transition temperature of the consumable. This increases the initial temperature of the consumable while preventing significant softening, bending, or jamming of the consumable during the pretreatment stage.

[0052] Under the action of the insulation material 4, the heat in the first heating chamber 9 and the second heating chamber 11 is effectively maintained, reducing heat loss, improving overall heating efficiency, and reducing energy consumption. After the consumables pass through the pretreatment device, their overall temperature is higher than the ambient temperature and closer to the working state of the nozzle 2. The additional heating required when entering the nozzle 2 is significantly reduced, thereby reducing the melt load and extrusion resistance of the nozzle 2.

[0053] Finally, the pre-treated filament enters the nozzle 2 in a more stable thermal state for melting and extrusion, making the extrusion process more continuous and uniform. This significantly reduces the problems of material output fluctuation, feeding slippage and nozzle 2 blockage caused by low-temperature filament, thereby improving the stability of the 3D printing process and the molding quality.

[0054] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments are merely illustrative of the technical concept and characteristics of the present invention, intended to enable those skilled in the art to understand and implement the invention, and should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A filament pretreatment device for a 3D printer, characterized in that: Includes a housing (7), a guide tube (10), a first heating chamber (9), a second heating chamber (11), a heating assembly, a temperature sensing element, and a control assembly. The housing (7) is installed on the machine frame (1). The housing (7) is equipped with a guide tube (10) and a heating component. The housing (7) has a slender structure along the material conveying direction and forms a straight channel for material to pass through. The wire of the material roll (3) is fed into the nozzle (2) of the 3D printer through the guide tube (10). The guide tube (10) is disposed in the straight channel and is used to axially guide and support the filamentous consumables passing through. The guide tube (10) is made of heat-resistant and low-friction material. Different specifications of the guide tube (10) can be replaced. The guide tube (10) is installed in the support protective cover (5). Using similar materials can reduce the conveying resistance of consumables during the pretreatment process. The heating component is disposed inside the housing (7) and covers the supporting protective cover (5) for heating the consumables inside the guide tube (10); Temperature sensing elements are used to detect the temperature status in the first heating chamber (9) and the second heating chamber (11) respectively. An external sleeve (6) is installed on the housing (7), which allows for quick replacement of the guide tube (10) or quick installation and maintenance of the heating components and the support protective cover (5) by disassembling the external sleeve (6). The first heating chamber (9) and the second heating chamber (11) are located in the space formed by the outer cylinder (6) and the shell (7). The outer cylinder (6) and the shell (7) are filled with heat-insulating material (4). The heating temperature of the second heating chamber (11) is higher than that of the first heating chamber (9). The control component is electrically connected to the heating component and the temperature detection component, and is used to control the heating components of the first heating chamber (9) and the second heating chamber (11) according to the detected temperature signal, so that the consumables through the pretreatment device are maintained in a preset low temperature constant temperature range.

2. The consumable pretreatment device for a 3D printer according to claim 1, characterized in that: The housing (7) is a box-type structure consisting of two detachable parts, which are fixed to the outside of the machine frame (1) by welding or bolts. Installed on the outside of the machine frame (1), it facilitates the modification of existing 3D printers without occupying or interfering with the internal space and structure of the 3D printer.

3. A consumable pretreatment device for a 3D printer according to claim 1 or 2, characterized in that: The housing (7) is made of stainless steel, aluminum alloy or heat-resistant engineering plastic.

4. The consumable pretreatment device for a 3D printer according to claim 1, characterized in that: The guide tube (10) is made of polytetrafluoroethylene or polyetheretherketone.

5. A consumable pretreatment device for a 3D printer according to claim 1, characterized in that: The insulation material (4) shall be at least one of the following: glass fiber cotton, ceramic fiber cotton, or aluminum silicate fiber cotton.

6. A consumable pretreatment device for a 3D printer according to claim 1, characterized in that: The heating assembly includes a flexible resistance heating element, which is electrically connected to the control assembly to achieve closed-loop control of the pretreatment temperature.

7. A consumable pretreatment device for a 3D printer according to claim 1, characterized in that: The supporting protective cover (5) extends out of the shell (7) and is a single-section or multi-section structure made of metal tubing.

8. A consumable pretreatment device for a 3D printer according to claim 1, characterized in that: The control component is configured to set a corresponding target preheating temperature based on the consumable material type, consumable diameter specification, and / or ambient temperature parameters, and to implement closed-loop temperature control for each heating zone, so that the pretreatment temperature of the consumable is lower than its glass transition temperature, thereby avoiding significant softening of the consumable.

9. A consumable pretreatment device for a 3D printer according to claim 1, characterized in that: The temperature sensing element is a thermocouple (8).

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