An Anti-clogging print head with directed flow system

Abstract

The invention relates to a print head (hotend) for additive manufacturing, specifically known in the literature as "Fused Filament Fabrication (FFF)" or "Fused Deposition Modeling (FDM)." This is aimed at three-dimensional (3D) printing technologies.

Description

[0001] AN ANTI-CLOGGING PRINT HEAD WITH DIRECTED FLOW SYSTEM

[0002] TECHNICAL FIELD

[0003] The invention pertains to a print head (hotend) for additive manufacturing, particularly referred to as “Fused Filament Fabrication (FFF)” or “Fused Deposition Modeling (FDM)” in the literature.

[0004] The invention is a hotend design for 3D printers that enables the simultaneous printing of two different materials (e.g., PLA and ABS) or two different colors, featuring a two-input, one-output configuration.

[0005] BACKGROUND

[0006] In the known state of the art, print heads include components such as the filament input (1 ), heater cartridge (2), temperature sensor (3), auxiliary middle channel mouth (4), output channel (6), and heater cartridge retaining screw hole (7). Figures 2, 3, and 4 illustrate traditional two-input, one-output hotend designs where filaments change direction by 90 degrees, leading to more difficult flow and frequent clogging. This situation adversely affects the efficiency of the printing process and creates problems in multi-material or multi-color printing.

[0007] In traditional two-input, one-output print heads, the filament inputs (1 ) are located at the top, and barrels are screwed into the top holes. As shown in Figure 2, these input holes open into the lower hole drilled through the middle section. The ends of the holes are sealed with a gasket and screw to direct the filament to the middle section’s output channel (6). In this scenario:

[0008] • As depicted in Figure 4, the filaments pushed through the barrels initially undergo a 90-degree directional change from the input (1) to the middle section and then toward the output channel (6), undergoing another 90-degree change. These directional changes increase friction and complicate the feeding of the filament to the print nozzle.

[0009] • Over time, the gaskets used in the outer holes of the middle section deteriorate and lead to material leakage outward.

[0010] • Since the outer holes in the middle section are sealed with screws and gaskets, as shown in Figure 2, dead zones (5) are created. In these areas, where there is almost no material flow, the accumulated materials over time burn, and new materials sticking to the burnt materials increasingly hinder the flow. Eventually, this leads to complete clogging, requiring high levels of maintenance. Additionally, if the flow is impeded, the predetermined amount of material flow will not occur, leading to defects in the printed samples.

[0011] In the aforementioned print heads, when attempting to print different materials together, such as PLA and ABS, clogs can occur due to the different printing temperatures required for each material. PLA can be printed at temperatures between 190-200°C, while ABS requires 220-250°C. Particularly during high-temperature ABS printing, material accumulation occurs at the points where the filaments undergo a 90- degree directional change in the print head. This increases friction and causes the material to burn and adhere to the channel walls at the corners. Initially, this situation makes the flow difficult, and over time, the accumulation of burned material leads to clogging. To prevent this issue, it has become necessary to increase the angles at the points of directional change to provide a smoother flow path, and to design a print head that is both compatible with traditional structures and easy and practical to produce.

[0012] AIM OF THE INVENTION

[0013] The print head (hotend) subject to the invention uses a 135-degree angle instead of the traditional 90-degree directional change for filament flow, facilitating a smoother filament transition. This reduces clogging issues and makes the printing process more seamless, while also simplifying production.

[0014] The print head can be easily applied to traditional two-input, one-output print heads and can be readily manufactured using conventional machining methods. The 135-degree directional change angles reduce friction, and since the filament flow holes directly merge at the output hole, no additional holes are needed. This eliminates dead zones, preventing material burns and clogs.

[0015] LIST OF FIGURES

[0016] Figure 1 A. General view of the invention

[0017] Figure 1 B. Isometric view of the invention

[0018] Figure2. Front view of the traditional two-input, one-output hotend

[0019] Figure3. Isometric view of the traditional two-input, one-output hotend Figure4. Schematic representation of filament flow in the traditional two-input, one-output hotend .

[0020] Equivalent of the numberings in the figures:

[0021] 1. Filament input

[0022] 2. Heater cartridge

[0023] 3. Temperature sensor

[0024] 4. Auxiliary middle channel mouth

[0025] 5. Dead zones

[0026] 6. Output channel

[0027] 7. Heater cartridge retaining screw hole

[0028] 1.1. Printing Head

[0029] 1.2. Filament Input

[0030] 1.3. Output Point

[0031] 1 .4. Direction Change Angle

[0032] DETAILED DESCRIPTION OF THE INVENTION

[0033] The invention encompasses a print head (1.1 ) that features 45-degree chamfered corners. The filament inputs (1.2) are drilled through these chamfered edges and merge at the output point (1.3). Like traditional two-input, one-output print heads, the filament inputs (1.2) are located at the top, and this design can be easily applied to conventional heads. Moreover, the absence of unnecessary channel holes and dead zones found in traditional print heads in this design allows for smoother filament flow and reduced friction. The 45-degree chamfering of the corners and the positioning of the flow holes at these points facilitate production ease.

[0034] The invention introduces a print head designed with 135-degree direction change angles (1.4) to prevent issues such as clogging, material accumulation, and burning encountered in traditional two-input, one-output print heads. This design ensures a smoother filament flow and minimizes friction, significantly preventing clogs. Additionally, the filament inputs (1.2) merge directly at the output point (1.3) without the need for an additional channel, which eliminates dead zones.

[0035] In contrast to the existing print heads where filaments undergo a 90-degree direction change, our invention utilizes 135-degree direction change angles (1.4). This adjustment results in less friction and smoother filament flow. While traditional systems often experience material accumulation and burning at the points of directional change, our invention largely prevents these problems by removing dead zones and allowing the filament flow to merge directly at the output point (1 .3). The invention can be easily manufactured using traditional machining methods, reducing production costs and enhancing applicability.

[0036] The invention consists of a single piece. The filament inputs (1 .2) are located at the top, similar to traditional two-input, one-output print heads, with 45-degree chamfers on the upper edges and filament inputs (1.2) drilled through these chamfer surfaces. Depending on the thread types of the barrels used at the filament inputs (1 .2), the screw sizes at the input mouths can vary between M5, M6, or M7. Similarly, the thread size at the output point (1 .3) where the nozzle is attached can also vary between M5, M6, or M7. While traditional two-input, one-output print heads experience clogging after printing approximately 1 kg of filament, our invention can print more than 5 kg of material without any clogging issues.

Claims

CLAIMS1. An anti-clogging print head with a directed flow system characterized by comprising a print head (1 .1 ) with 45-degree chamfered corners, filament inputs (1 .2) located at the top part of the print head (1 .1), an output point (1 .3) where the filament inputs (1.2) converge and connect, and 135-degree direction change angles (1.4) designed to prevent issues such as clogging, material accumulation, and burning.

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