Capricorn PTFE Tubing

Type
In stock, ready to ship.
Price is per meter. If multiple meters are ordered, will send in continuous lengths when possible.

 

Capricorn premium PTFE Tubing is enhanced with a proprietary blend of high performance additives. 1.8mm inner, 4mm outer diameter for 1.75mm filaments.

 



 

 Brand Capricorn
ID (+/-0.05mm) 1.9 mm (XS) 2.0mm (TL)
OD (+/-0.025mm) 4.0 mm
Capricorn premium PTFE tubing is the best PTFE Bowden tubing you can buy for your 3D printer. Comes in two types:

 

Type TL - Translucent

TL Series of translucent light blue tubing offers the advantage of being able to see the filament inside the tube. Many customers prefer this because it allows them to quickly diagnose problems such as breaks in the filament, and gives them instant visual feedback of the location of the filament end.

Type XS - Low Friction.

A proprietary secret ingredient that is able to actually reduce the friction coefficient to below that of PTFE alone. This ingredient is opaque, and does make the tube slightly more rigid than TL series. However, if you want the absolute lowest friction for pushing the thickest, chunkiest filaments through your hot end without clogging, this is the tubing for you.

 

Guaranteed to always be the right diameter and perfectly round. Print flexible filaments without the binding up that happens with over-diameter tubes.

 

Technical Specifications

PTFE, or Polytetrafluoroethylene, is a synthetic polymer commonly used as a coating for non-stick pots and pans. It is the slipperiest substance known to man, and is said to be the only surface to which a gecko cannot stick. Although Bowden tubes can be made from several different polymers, PTFE is generally considered the best because of its high melting point and low coefficient of friction.

1.75mm Bowden tubing, because of its small diameter, is made with an expensive paste extrusion process. Very precise equipment is needed to obtain a consistent shape and internal diameter. Additives such as colorant are difficult, because the PTFE doesn't readily want to mix with anything. Plain white PTFE is the cheapest and most common.

Capricorn tubing is manufactured using the most sophisticated equipment currently available. It always comes out perfectly round, and the diameter stays as consistent as possible.

Capricorn TL Bowden Tubing is made from pure virgin Japanese PTFE resin. This resin is not only translucent, it is also slightly softer and more flexible than average PTFE.

Just like filaments, Bowden tubes vary in their real-world diameters. Tubing is often labeled as having an inside diameter of 2.0mm. The measured diameter may vary, however, anywhere from 1.75 to 2.15. Capricorn TL series tube, which is labeled as a nominal 2.0mm inner diameter runs between 1.95 and 2.05.

This makes it well suited for printing larger or uneven diameter filaments such as wood and metal flake filaments. Higher end wood filaments especially have a tendency to be "chunky," containing large bits of real wood.

Capricorn XS Bowden Tubing is also made from the highest quality pure virgin Japanese PTFE, and formed using the paste extrusion process. However, we have added a "Secret Sauce" which lowers the coefficient of friction. This additive also makes the tubing opaque.

Capricorn XS tubing has a nominal internal diameter of 1.9mm, running from 1.85 to 1.95. This smaller diameter makes it ideal for printing flexible filaments, because there is no room for the filament to bind up inside the tube. The low friction coefficient allows any filament to glide through the tube with ease.

  Opaque White PTFE Translucent White PTFE TL Series Light Blue XS Series Dark Blue
Additives None None Blue Color

Blue Color and Secret High Performance Additive Mixture

Best For Chunky Filaments No No Yes Maybe
Best For Flexible Filaments No No No Yes
Can See Through No Yes Yes No
Pulling Friction1 1.00 0.90 0.70 0.76
Color White White, Translucent Blue, Translucent Dark Blue
Density (kg/m3) 2100-2200 2100-2200 2100 +/-100 2300 +/-100
Hardness 58-62 58-62 55 60-65
Inner Diameter (mm) > 2.0 > 2.0 2.0 +/- 0.05 1.9 +/- 0.05
Linear Thermal Expansion at 250°C 3.4-3.6% 3.4-3.6% 3.4-3.6% 2.2-3.3%
Material Cheapest PTFE Better PTFE Highest Quality Pure Virgin PTFE Highest Quality Pure Virgin PTFE
Melting Point (°C)2 as low as 220 around 260-327 around 340 around 340
Outer Diameter about 4 mm about 4 mm 4.075 +/- 0.025 3.99 +/-0.025
Roundness Variable Variable < 0.1 < 0.1
Stiffness High High Medium Medium High
Thermal Conductivity (W/m-k) 0.25 0.25 0.25 0.25
Wear Rate (gm/s) 0.01 0.01 0.01 0.01
Young's Modulus (GPa) < 0.50 < 0.50 0.50 0.532
   
1 Pulling Friction is calculated as the average force required to pull 1.2 meters of 1.75mm PLA filament through 1 meter of tubing at a constant speed, relative to 1 meter of cheap white reference tubing. Note that although we observed the friction of the TL series to be lower than our XS series, it also has a larger internal diameter.
2 PTFE does not transition quickly from a solid to liquid, but acts as a glass, slowly softening. Temperatures were approximated by heating samples of all tubing simultaneously, observing how quickly each one began to deform.

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