The throat, also known as the heat break in English, is an essential component in the hotend of a 3D printer. Its main function is to provide a thermal and mechanical transition between the heater block and the nozzle. In this post we will talk about how it works, its different versions and the most used materials.
Hotend throat operation:
The throat is the component of the hotend that is part of the three temperature zones: cold zone, warm zone and hot zone. The hot zone is in direct contact with the heating block and becomes very hot, while the cold zone is in contact with the heat sink and remains at a lower temperature. This gradual thermal transition helps prevent heat from spreading from the heating block to the cold section, which could cause clogging or extrusion problems.
Differences between the throats according to the All Metal version or the Teflon version:
- All-Metal Throats: These throats are made entirely of metal, such as stainless steel or titanium, and do not have internal Teflon linings. They are suitable for printing materials that require high extrusion temperatures, such as ABS, nylon or polycarbonate, since they can withstand higher temperatures without degrading, but they can also print materials such as PLA. Full metal throats offer excellent thermal conductivity and allow for a more efficient heat transition from heater block to nozzle.
- Teflon (PTFE) Version Throats: These throats have a larger internal diameter, which allows a Teflon (Polytetrafluoroethylene) tube to pass through the hot section. Teflon is a material with low friction and high heat resistance. Teflon tube grooves are ideal for printing low temperature materials, especially recommended for PLA, as the Teflon coating reduces friction and prevents the filament from sticking or clogging. However, Teflon has a maximum operating temperature, usually around 250-280ºC, so it is not suitable for printing materials that require higher temperatures.
The choice between a full metal throat and a Teflon tube throat depends on the materials you want to print and the required extrusion temperatures. If you plan to print high temperature materials, such as nylon, a full metal throat is more suitable. If you're focusing on low-temperature materials, like PLA, a Teflon-tubed throat will suffice.
It is important to take into account the specifications and recommendations of the manufacturer of your 3D printer, as some models may have specific requirements for the throats that can be used.
Most used materials:
Stainless steel, titanium, and bimetal throats are popular choices in 3D printing due to their unique characteristics and properties. Below we talk about each of these materials in terms of working temperatures, qualities and temperature flows in the throat itself:
- Gargantas de acero inoxidable:
Stainless steel throats are suitable for moderate to high working temperatures. They can withstand extrusion temperatures of up to around 280-300ºC, making them suitable for printing a wide range of materials, including ABS, PLA, PETG and other common thermoplastics.
Stainless steel is a strong and durable material. It provides good thermal conductivity and is less prone to corrosion compared to other metals. This ensures efficient heat transfer and extended throat life.
In a stainless steel throat, heat is gradually transferred from the hot section (in contact with the heater block) to the cold section (in contact with the heat sink). The stainless steel throat allows for a stable and controlled temperature flow along its length.
- Titanium Throats:
Titanium is a lightweight and corrosion resistant material. Titanium throats offer high thermal conductivity and increased strength at high temperatures, making them ideal for high-end 3D printing applications.
Thanks to its excellent machinability and its super-precise production process, these grooves can have very tight tolerances. Their interior finish is usually a mirror effect, which favors the passage of sticky filaments with high friction, such as flexible materials.
Like stainless steel throats, titanium throats allow controlled temperature flow from the hot section to the cold section. Gradual heat transfer prevents problems such as filament clogging or excessive cooling in the hot section.
- Bimetal Throats:
Bimetal throats combine two metals with different coefficients of thermal expansion to improve performance in terms of temperature control. These grooves are ideal for printing high-temperature materials, as they minimize thermal expansion and contraction during printing.
Bimetal throats are typically made from a combination of titanium and copper, giving them high strength at high temperatures and excellent durability. They offer efficient thermal conductivity and controlled temperature flow. Titanium reduces heat conduction in the heating position and copper effectively dissipates heat for better temperature flow.
Clicking here you can see our selection of throats, if you have any questions, we will be happy to solve it!
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