System for inserting woven fiber reinforcements during FDM 3D printing

Abstract

A system (100) for the automated in-situ placement of a woven fiber reinforcement during additive manufacturing using fused deposition modeling (FDM), wherein the system (100) comprises: an FDM printing unit (1) configured to apply a thermoplastic material layer by layer onto a build platform; an auxiliary reinforcement module (2) coupled to the FDM printing unit (1); a feed mechanism (3) for woven fiber webs, configured to feed a woven fiber web from a stock; a cutting mechanism (4) configured to cut the woven fiberboard to a desired geometry; an adhesive application mechanism (5) configured to apply an adhesive to a printed polymer layer; a placement and alignment mechanism (6) configured to place the cut woven fiberboard onto the printed polymer layer; a compression or stabilization mechanism (7) configured to exert a contact pressure to maintain the bond between the woven fiber sheet and the printed polymer layer; and a control and synchronization unit (8) configured to (i) detect a predefined reinforcement insertion layer during the printing process, (ii) instruct a controlled pause of the FDM printing unit (1) without removing a partially printed component from the build platform, (iii) actuate the adhesive dispensing mechanism (5), the woven fiber sheet feeding mechanism (3), the cutting mechanism (4), the placement and alignment mechanism (6), and the compaction or stabilization mechanism (7) to insert the woven fiber sheet onto the predefined reinforcement insertion layer, and (iv) command the resumption of the printing process to apply thermoplastic material over the woven fiber sheet to encapsulate the woven fiber sheet within the polymer layers and form a laminated composite material.

Description

INVENTION AREA

[0001] The present invention relates to additive manufacturing, in particular 3D printing based on fused deposition modeling (FDM). The invention specifically relates to a system for the automated insertion of a reinforcement made of woven fiber webs at predefined layer heights during an ongoing FDM print in order to form a laminated polymer-fiber composite component without removing the partially printed component from the build platform. BACKGROUND OF THE INVENTION

[0002] The subject matter discussed in the "Background" section should not be considered prior art solely because it is mentioned in that section. Likewise, a problem mentioned in the "Background" section or related to the subject matter of the "Background" section should not be considered prior art. The subject matter in the "Background" section merely presents various approaches, which could themselves also be inventions.

[0003] Additive manufacturing using fused deposition modeling (FDM) has gained popularity due to its design freedom, low cost, and ability to create complex shapes. However, standard thermoplastic parts produced with FDM often exhibit low mechanical strength, anisotropy, and poor load-bearing capacity. To overcome these limitations, several fiber-reinforced 3D printing methods have been investigated. One commonly used method is the incorporation of cut or short fibers into the thermoplastic filament. While such filaments offer moderate stiffness advantages, they often result in reduced fiber ductility, nozzle wear, and limited strength gains due to random fiber orientation and low fiber content. Furthermore, cut fibers have lower reinforcement efficiency than continuous fibers.An alternative is the use of continuous fiber tow deposition in conjunction with thermoplastic extrusion. While this technology increases directional strength, it is generally limited to simple fiber paths, restricted orientation control, and high equipment costs. The use of continuous fiber reinforcements cannot provide multidirectional load-bearing properties in the resulting composites. Manual insertion of fiber sheets or fabrics during the interrupted printing process has also been attempted in research settings. However, such technologies are highly operator-dependent, exhibit low reproducibility, and are unsuitable for industrial or automated production. Furthermore, manual operations lead to a loss of positional accuracy and an increased probability of errors.Other methods for manufacturing fabric-reinforced polymer composites include hand lay-up, spray lay-up, and resin transfer molding, to name a few, but all these methods use only thermosetting resins. Therefore, current approaches do not offer a scalable, automated, or geometry-adaptive solution for incorporating fabric-reinforced fibers into FDM-printed thermoplastic components.

[0004] Fused Deposition Modeling (FDM) is frequently used to manufacture polymer components by depositing thermoplastic material layer by layer through a heated extrusion die. While FDM enables rapid prototyping and cost-effective manufacturing, printed polymer parts often exhibit limited strength, stiffness, and fatigue resistance, particularly along the interlayer (Z-direction), due to the anisotropic bonding between the layers.

[0005] To improve mechanical performance, reinforcement strategies such as cut fiber, continuous fiber, and woven-based laminates are used in the production of composite materials. However, conventional approaches to embedding woven fiber sheets in FDM prints typically require manual intervention—stopping the printer, opening the build chamber, manually placing a cut fiber sheet, and resuming the printing process. Manual reinforcement is time-consuming, leads to misalignment, causes inconsistent bonds, and can disrupt the temperature-controlled environment required for strong interlayer adhesion. Furthermore, many established approaches require removing the part from the build plate for secondary lamination, resulting in poor repeatability and limited automation.

[0006] Therefore, there is a need for a retrofittable system that automatically interrupts printing at a predefined layer, applies a compatible adhesive, feeds and cuts a woven fiberboard to a desired geometry, precisely places and aligns the board on the printed polymer layer, applies compaction to stabilize the bond, and resumes printing to encapsulate the reinforcement, thereby forming a laminated composite structure in a controlled and repeatable manner.

[0007] The use of any examples or illustrative phrases (e.g., "as") relating to specific embodiments serves only to better illustrate the invention and does not constitute a limitation of the otherwise claimed scope of the invention. No phrase in the description shall be construed as indicating an unclaimed element that is essential for carrying out the invention.

[0008] The information disclosed above in this "Background" section is provided solely for a better understanding of the background of the invention and may therefore contain information that is not part of the prior art already known to a person skilled in the art in this country. SUMMARY

[0009] Before describing the systems and methods presented here, it should be noted that this application is not limited to the specific systems and methods described, as there may be several possible embodiments not expressly presented in this disclosure. It should also be noted that the terminology used in the description serves only to describe the specific versions or embodiments and is not intended to limit the scope of this application.

[0010] In one aspect, the invention provides for an auxiliary reinforcement module (2) coupled to an FDM printing unit (1). During the printing process, a control and synchronization unit (8) detects a predefined layer height (reinforcement insertion layer) and commands a controlled pause of the printer. Without removing the partially printed component from the build platform, the control unit coordinates the dispensing of a thermoplastic-compatible adhesive by an adhesive dispensing mechanism (5), the feeding of a woven fiberboard using a feeding mechanism (3), the cutting of the woven fiberboard to a desired geometry by a cutting mechanism (4), the placement and alignment of the cut board by a placement and alignment mechanism (6), and the application of pressure using a compression or stabilization mechanism (7).After stabilization, the control unit commands the resumption of the printing process, so that thermoplastic material is applied over the woven fiberboard, encapsulating it between polymer layers and creating a laminated composite structure. The system is programmable to insert multiple woven fiberboards at different layer heights to create a multilayer laminated structure, and the module (2) is configured as a retrofit kit for standard FDM printers. BRIEF DESCRIPTION OF THE DRAWING

[0011] To clarify various aspects of some embodiments of the present invention, a more detailed description of the invention is given with reference to specific embodiments shown in the accompanying drawing. It is understood that this drawing represents only illustrative embodiments of the invention and is therefore not to be considered a limitation of its scope. The invention is described and explained with additional specificity and detail using the accompanying drawing.

[0012] To make the advantages of the present invention easily understandable, the invention is described in detail below with reference to the accompanying drawing. However, it should be noted that the scope of the invention is not limited to the accompanying drawing, which: Fig. Figure 1 shows a block diagram representation of the system (100) for inserting a woven fiber reinforcement during FDM 3D printing. DETAILED DESCRIPTION

[0013] The present invention relates to a system (100) for inserting a reinforcement made of woven fiber webs during FDM 3D printing.

[0014] Fig. shows a detailed block diagram representation of the system (100) for inserting a reinforcement made of woven fiber webs during FDM 3D printing.

[0015] The present invention relates to a system (100) for the automated insertion of a reinforcement made of woven fiber webs during FDM 3D printing (Fused Deposition Modeling), wherein the reinforcement is inserted at one or more predefined layer heights while the component remains on the build platform of an FDM printing unit (1), thereby forming a laminated polymer-fiber composite structure.

[0016] The system (100) generally comprises an FDM printing unit (1) and an auxiliary reinforcement module (2) connected to the FDM printing unit (1). The auxiliary reinforcement module (2) comprises a feeding mechanism (3) for woven fiberboard, a cutting mechanism (4), an adhesive dosing mechanism (5), a placement and alignment mechanism (6), and a compaction or stabilization mechanism (7), all of which are coordinated by a control and synchronization unit (8).

[0017] During operation, the FDM printing unit (1) applies a thermoplastic material layer by layer to a build platform according to a programmed toolpath. The thermoplastic material can be any FDM-compatible polymer, such as PLA, ABS, PETG, nylon, polycarbonate, or equivalent materials that can be extruded and fused in successive layers.

[0018] The auxiliary reinforcement module (2) is configured as a modular attachment that is mounted next to or on a frame of the FDM printing unit (1). In a preferred embodiment, the module (2) is retrofittable, so that a standard FDM printer can be upgraded for the automatic insertion of woven fiber webs without requiring major structural modifications to the printer (1).

[0019] The woven fiber web reinforcement used in the system (100) is supplied in web or roll form and can include woven glass fibers, woven carbon fibers, woven basalt fibers, woven aramid fibers, or other woven textile reinforcements suitable for reinforcing composites. The woven architecture allows for planar reinforcement across a printed layer, thereby improving stiffness and strength along the printed plane and increasing resistance to crack growth and layer delamination.

[0020] The feeding mechanism (3) for the woven fiber sheet is configured to feed the woven fiber sheet from a feeder to a processing area near the build platform. In one embodiment, the feeding mechanism (3) comprises a fiber spool mounted on a holder and a roller feeder that advances the sheet at a controlled feed rate while maintaining controlled tension to prevent wrinkling, sagging, distortion, or misplacement during insertion.

[0021] In a further embodiment, the feeding mechanism (3) comprises a gripper which is actuated by an actuator to pull the woven fiberboard over the printed polymer layer at the reinforcement insertion layer. The gripper can be configured to temporarily clamp the board and pull it to a target position above the printed area for subsequent cutting and placement.

[0022] The cutting mechanism (4) is configured to trim the woven fiber sheet to a desired geometry prior to placement. In one embodiment, the cutting mechanism (4) comprises a shear cutting mechanism that performs a cut in place after the sheet has been pulled into position. The cut geometry can be selected to correspond to a reinforcement area that matches the cross-section of the part at the insertion layer, so that the inserted sheet reinforces the intended area without affecting the peripheral features.

[0023] The adhesive dispensing mechanism (5) is configured to dispense an adhesive onto the printed polymer layer prior to the placement of the woven fiber sheet. In one embodiment, the adhesive dispensing mechanism (5) comprises an injector mechanism configured to apply a thin layer of a thermoplastic-compatible, solvent-based adhesive. The adhesive layer facilitates bonding between the woven fiber sheet and the printed polymer layer and improves the sheet's stability during the transition from pause to resume printing.

[0024] The adhesive metering mechanism (5) can be configured to meter adhesive in a pattern according to the desired reinforcement area, for example by metering adhesive in lines, dots or as a surface coating, thereby reducing excess adhesive and improving the repeatability of the bonding surface.

[0025] The placement and alignment mechanism (6) is configured to place the cut woven fiberboard onto the adhesive-coated printed polymer layer. The mechanism (6) may include guide surfaces, positioning arms, and / or actuators that move the cut board to a target insertion position, ensuring that the board is aligned relative to the printed geometry. Correct alignment prevents edge curling, overlaps, and unintended misalignments that could otherwise lead to nozzle collisions or internal voids during encapsulation.

[0026] The compaction or stabilization mechanism (7) is configured to exert contact pressure on the woven fiberboard after placement to maintain the bond and prevent displacement before the printing process is resumed. In one embodiment, the compaction mechanism (7) comprises a roller press configured to roll over the board to press the woven fiberboard into close contact with the adhesive-coated printed polymer layer, thereby improving interface wetting, reducing trapped air inclusions, and minimizing board lifting during subsequent deposition.

[0027] The control and synchronization unit (8) is configured to coordinate the reinforcement insertion processes with the printing process. During the printing process, the unit (8) detects a predefined reinforcement insertion layer and commands a controlled pause of the FDM printing unit (1) without removing the partially printed component from the build platform. This controlled pause ensures positional integrity and prevents loss of registration between the printer's coordinate system and the component being printed.

[0028] In one embodiment, the control and synchronization unit (8) is configured to communicate with the printer firmware of the FDM printing unit (1) and synchronize a pause, process, and resume workflow using G-code-based pause and resume commands and coordination by an external controller. For example, the unit (8) can send or trigger a pause command at a predefined layer, control the auxiliary reinforcement module (2) to complete insertion tasks, and then trigger a resume command to continue deposition from the paused layer.

[0029] During the controlled pause, the control and synchronization unit (8) can retract the extrusion nozzle of the FDM printing unit (1) into a non-printing position to avoid contact with the partially printed part and to create space for reinforcement insertion operations. The non-printing position can be a parked coordinate outside the part perimeter or at a safe Z-height above the build area.

[0030] Furthermore, during the controlled pause, the control and synchronization unit (8) maintains the temperature of the build platform (and optionally the chamber temperature, if available) to preserve adhesion between the layers. Maintaining the temperature reduces premature cooling of the top polymer layer and allows for improved bonding and fusion when the printing process resumes and thermoplastic material is deposited over the inserted woven fiber sheet.

[0031] Once the controlled pause is activated, the control and synchronization unit (8) actuates the adhesive dispensing mechanism (5) to apply adhesive to the printed polymer layer at the insertion layer. The control unit (8) then actuates the fabric feed mechanism (3) to advance the fabric and the cutting mechanism (4) to cut the fabric to the desired geometry, followed by the actuation of the placement and alignment mechanism (6) to position the cut fabric on the adhesive-coated area.

[0032] After placement, the control and synchronization unit (8) actuates the compaction or stabilization mechanism (7) to exert pressure on the inserted woven fiberboard, thereby improving adhesion, reducing the risk of displacement and preparing a stable surface for subsequent deposition.

[0033] After completion of the reinforcement introduction sequence, the control and synchronization unit (8) commands the FDM printing unit (1) to resume the printing process, so that thermoplastic material is applied over the woven fiberboard to encapsulate it within the polymer layers. This encapsulation forms a laminated composite structure in which the woven fiberboard acts as an internal reinforcing layer between the printed polymer layers.

[0034] In one embodiment, the control and synchronization unit (8) is programmable to control the number, position, and sequence of multiple insertions of woven fiber sheets at different layer heights. Accordingly, the system (100) can produce a multilayer laminated structure comprising multiple reinforcing sheets embedded at selected heights within the final printed component, thereby improving mechanical performance according to design requirements.

[0035] The system (100) offers improved repeatability and reduces human intervention compared to manual reinforcement processes. By integrating feeding, cutting, adhesive application, placement / alignment, and compaction into a synchronized control sequence, the system (100) enables consistent reinforcement insertion while maintaining the positional and temperature conditions required for a strong bond during FDM printing.

[0036] The term "woven fiberboard" includes, but is not limited to, woven glass fibers, woven carbon fibers, woven basalt fibers, woven aramid fibers, or other woven reinforcing fabrics compatible with the production of polymer composites. The thermoplastic material applied by the FDM printing unit (1) may include, but is not limited to, PLA, ABS, PETG, nylon, polycarbonate, or other printable thermoplastic materials. FDM printing unit (1)

[0037] The FDM printing unit (1) can be any commercially available FDM 3D printer configured to deposit thermoplastic material layer by layer through an extrusion nozzle onto a build platform to form a partially printed part and a final printed part. The printing unit (1) executes a toolpath defined by the printer firmware, which can be controlled by G-code commands. Auxiliary amplification module (2)

[0038] The auxiliary reinforcement module (2) is mechanically and / or electronically coupled to the FDM printing unit (1). In a preferred embodiment, the module (2) is configured as a modular attachment that can be mounted next to a printer frame, thus enabling the retrofitting of an existing FDM printer with a reinforcement insertion function.

[0039] The module (2) houses and carries the feeding mechanism (3), the cutting mechanism (4), the adhesive dosing mechanism (5), the placement / alignment mechanism (6) and the compaction mechanism (7) and provides an interface for coordination with the control and synchronization unit (8). Feeding mechanism (3) for woven fiberboard

[0040] The feeding mechanism (3) for woven fiberboard is configured to feed a woven fiberboard from a supply into a processing area near the build platform. In a preferred embodiment, the feeding mechanism (3) comprises a fiber spool and a roller feeder configured to advance the woven fiberboard while maintaining controlled tension.

[0041] In one embodiment, the feeding mechanism (3) further comprises a gripper which is actuated by an actuator to pull the woven fiber sheet over the adhesive-coated printed polymer layer before cutting. The controlled tension helps to avoid creases, distortions, or misalignments during placement. Cutting mechanism (4)

[0042] The cutting mechanism (4) is configured to trim the woven fiber sheet to a desired geometry suitable for insertion into the predefined reinforcement insert layer. In one embodiment, the cutting mechanism (4) comprises a shear cutting mechanism configured to perform on-site cutting after the woven fiber sheet has been drawn over the printed polymer layer. The desired geometry can correspond to the cross-sectional reinforcement area of ​​the part to be printed and can be selected based on print settings stored in the control and synchronization unit (8). Adhesive dispensing mechanism (5)

[0043] The adhesive metering mechanism (5) is configured to apply an adhesive to a printed polymer layer prior to the application of the woven fiber sheet. In one embodiment, the adhesive metering mechanism (5) comprises an injector mechanism configured to apply a thin layer of a thermoplastic-compatible, solvent-based adhesive. The adhesive promotes improved bonding between the printed polymer layer and the woven fiber sheet and aids in stabilization before the printing process continues. Placement and alignment mechanism (6)

[0044] The placement and alignment mechanism (6) is configured to lay the cut fiber fabric onto the printed polymer layer and align it as required. The mechanism (6) may include guide elements and actuators to ensure accurate placement relative to the printed geometry. In one embodiment, the mechanism (6) places the fiber fabric onto the adhesive-coated area and aligns it to avoid overlap with unwanted areas, thereby improving repeatability and minimizing part defects. Compression or stabilization mechanism (7)

[0045] The compaction or stabilization mechanism (7) is configured to exert a contact pressure to maintain the bond between the woven fiberboard and the printed polymer layer. In one embodiment, the mechanism (7) comprises a roller press configured to compact the woven fiberboard onto the printed polymer layer to improve the bond and prevent displacement before the printing process continues. Control and synchronization unit (8) and workflow

[0046] The control and synchronization unit (8) coordinates the pressure and amplification application processes. The unit (8) is configured such that it (i) to detect a predefined reinforcement insertion layer during the printing process; (ii) to command a controlled pause of the FDM printing unit (1) without removing a partially printed component from the build platform; (iii) to actuate the adhesive dispensing mechanism (5), the woven fiber sheet feeding mechanism (3), the cutting mechanism (4), the placement and alignment mechanism (6) and the compaction or stabilization mechanism (7) to insert the woven fiber sheet into the predefined reinforcement insertion layer; and (iv) to control the resumption of the printing process to apply thermoplastic material over the woven fiberboard to encapsulate it in polymer layers and form a laminated composite material. Firmware coordination

[0047] In one embodiment, the control and synchronization unit (8) is configured to communicate with the printer firmware of the FDM printing unit (1) and synchronize the “pause-process-resume” workflow using G-code-based pause and resume commands and the coordination of external controls. Controlled break and temperature maintenance

[0048] In one embodiment, during the controlled pause, the control and synchronization unit (8) retracts an extrusion nozzle of the FDM printing unit (1) into a non-printing position and maintains the temperature of the build platform to preserve adhesion between the layers before resuming the printing process. Multiple insoles

[0049] In one embodiment, the control and synchronization unit (8) is programmable to control the number, position and sequence of multiple insertions of woven fiber webs at different layer heights, thereby forming a multilayer laminated structure within the printed component. ADVANTAGES OF THE INVENTION • Automated and repeatable insertion of reinforcing fabrics made of woven fibers during FDM printing. • Reduced manual intervention and reduced placement / alignment errors. • Improved bond through adhesive application and compaction prior to encapsulation. • Possibility of producing multilayer laminated composite structures with programmable insertion layers. • Retrofit capability through the attachment of the additional reinforcement module next to a standard FDM printer frame. • The insertion process takes place without the need to remove the partially printed component from the build platform, which improves process stability.

[0050] Although the invention is described with particular reference to components (1) to (8), it is understood that variations in the mechanical configuration, the actuation method and the fastening arrangements may be adopted without deviating from the scope of the claims, provided that the system continues to perform the controlled pause and the automated insertion and encapsulation of the woven fiber reinforcement during FDM printing.

[0051] The figure and the preceding description provide examples of embodiments. Those skilled in the art will recognize that one or more of the described elements can be combined to form a single functional element. Alternatively, certain elements can be divided into several functional elements. Elements from one embodiment can be added to another embodiment. For example, the sequence of the processes described here can be changed and is not limited to the manner described here. Furthermore, the actions of a block diagram need not be implemented in the order shown, nor does it necessarily have to be executed all actions. In addition, those actions that are not dependent on other actions can be executed in parallel with the other actions. The scope of embodiments is by no means limited by these specific examples.

[0052] Although the embodiments of the invention have been described in language relating to structural features and / or methods, it should be noted that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as examples of embodiments of the invention.

Claims

[1] A system (100) for automated in-situ placement of a woven fiber reinforcement during additive manufacturing using fused deposition modeling (FDM), wherein the system (100) comprises: an FDM printing unit (1) configured to apply a thermoplastic material layer by layer onto a build platform; an auxiliary reinforcement module (2) coupled to the FDM printing unit (1); a feed mechanism (3) for woven fiber webs, configured to feed a woven fiber web from a stock; a cutting mechanism (4) configured to cut the woven fiberboard to a desired geometry; an adhesive application mechanism (5) configured to apply an adhesive to a printed polymer layer; a placement and alignment mechanism (6) configured to place the cut woven fiberboard onto the printed polymer layer; a compression or stabilization mechanism (7) configured to exert a contact pressure to maintain the bond between the woven fiber sheet and the printed polymer layer; and a control and synchronization unit (8) configured to (i) detect a predefined reinforcement insertion layer during the printing process, (ii) instruct a controlled pause of the FDM printing unit (1) without removing a partially printed component from the build platform, (iii) actuate the adhesive dispensing mechanism (5), the woven fiber sheet feeding mechanism (3), the cutting mechanism (4), the placement and alignment mechanism (6), and the compaction or stabilization mechanism (7) to insert the woven fiber sheet onto the predefined reinforcement insertion layer, and (iv) command the resumption of the printing process to apply thermoplastic material over the woven fiber sheet to encapsulate the woven fiber sheet within the polymer layers and form a laminated composite material. [2] System (100) according to claim 1, wherein the control and synchronization unit (8) is configured to communicate with the printer firmware of the FDM printing unit (1) and synchronize a 'pause-process-resume' workflow using G-code-based pause and resume commands and external control coordination. [3] System (100) according to claim 1, wherein the control and synchronization unit (8) is configured to retract an extrusion nozzle of the FDM printing unit (1) into a non-printing position during the controlled pause and maintain the temperature of the build platform to preserve adhesion between the layers before resuming the printing process. [4] System (100) according to claim 1, wherein the feeding mechanism (3) for woven fiberboard comprises a fiber spool and a roller feeding arrangement configured to advance the woven fiberboard into a processing zone while maintaining controlled tension of the woven fiberboard. [5] System (100) according to claim 4, wherein the feeding mechanism (3) for the woven fiber sheet further comprises a gripper which is actuated by an actuator to pull the woven fiber sheet over the adhesive-coated printed polymer layer prior to cutting. [6] System (100) according to claim 1, wherein the cutting mechanism (4) comprises a scissor cutting mechanism configured to cut the fabric in place after it has been drawn over the printed polymer layer. [7] System (100) according to claim 1, wherein the adhesive dispensing mechanism (5) comprises an injector mechanism configured to apply a thin layer of a thermoplastic-compatible solvent-based adhesive to the printed polymer layer prior to the application of the woven fiber sheet. [8] System (100) according to claim 1, wherein the compaction or stabilization mechanism (7) comprises a roller press configured to compact the woven fiber sheet onto the printed polymer layer to improve adhesion and prevent displacement of the woven fiber sheet before the printing process continues. [9] System (100) according to claim 1, wherein the control and synchronization unit (8) is programmable to control the number, position and sequence of multiple insertions of woven fiberboards at different layer heights to form a multilayer laminated structure. [10] System (100) according to claim 1, wherein the additional reinforcement module (2) is configured as a modular attachment that can be mounted next to a printer frame to retrofit a standard FDM 3D printer with the ability to insert a woven fiberboard on site.

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