Monday, August 19, 2024

Plate Lab - Glass Fiber based Building Plates - Part I - The Basics

3D Printing + Plate Lab

This is a boring page. Skip it if you don't care about the materials used in your glass fiber / carbon based Building Plate.

Still with me? Okay. Here we go... Remember: everything in this post is about using glass (carbon) fiber based materials as build plates.


If you have any better (re)sources, links, information, or if you spot any mistakes, please drop me a line in the comments section!


1. The Basics


1.1 Material abuse

When you think about it, using a laminated Glass Fiber board for 3D Printing is taking the material out of its comfort zone, and using it for something it was never intended for. These materials offer high insulation (something we don't want), have a reasonable surface, and are able to withstand forces parallel to the surface, as well as perpendicular TOWARDS the surface. None of these materials were designed to handle forces pulling on their top layer (as happens with crimping / warping 3D printed objects).

How well 3D printed objects hold on to the build plate surface is defined by both the printed material  as well as the material of the build plate itself, and the way the build plate has been manufactured.


1.2 (Chinese) websites vs. Standards

Websites can be a great source of information, a confusion mess of incomprehensible translations, or a big bag of lies. I noticed that - especially - Chinese websites seem to have troubles separating standards from product identifiers. So, always check your sources!

Some standards aren't exactly standards, or allow for a lot of freeway when it comes to product definitions. There are a few 'formal' definitions such as the NEMA FR4, G10 and G11 standards, but (of course) you typically have to pay to obtain them.

I'll try to combine the stuff I could find into something usable, which might not entirely match any standards - as far as those exist, and are of interest to the 3D Print community.


Note: each manufacturer may have their own take on those 'standards', with materials that sometimes exceed those of one standard, but fail in other aspects. Even worse, some suppliers and vendors might simply lie. Yep. Those things happen, like bamboo that's painted to look like iron, and melamine powder used to create fake milk...

Webshops could easily sell black FR1 or G9, and call it something else. Both materials contain formaldehyde and should not be used as printing surfaces! Make sure to buy the right materials when building or buying glass fiber based plates!


1.3 Standards versus Standards

G10 is a generic construction material, and the G10 standard is focused on that. FR4 is focusing on it's Fire Retardant capabilities. In other words, FR4 isn't better that a G10 plate - it could be the other way around, why not?

In that same way, an FR4 from manufacturer A might be way better (for our 3D Printing purposes) than that of manufacturer B. If they both match of exceed the FR4 requirements, they both can claim to be FR4 compliant materials, even if the actual characteristics may be hugely different.

Muller Alhorn puts it like this:

" It is important to note that these values ​​should be considered general estimates only and may vary slightly depending on the manufacturer and specific product characteristics. A thorough review of each product's technical data sheet is required to ensure that the material meets the requirements. "

No further comments 😏

Here's a table from that same page:


(Click any image to enlarge)


For the sake of argument, and to save everybody some time (here's the second hint to skip the boring remainder 😏):

  • 3240 - material up to 110 degrees - bed up to 90 degrees C - nozzle up to ?
  • G10 / FR4 - material up to 130 degrees - bed up to 110 degrees C - nozzle up to ?
  • G11 / FR5 - material up to 150 degrees - bed up to 130 degrees C - nozzle up to ?


The temperatures above are the limits at which the fiber based surface may fail after extended exposure. Don't forget that the nozzle and the printed material may locally heat up the bed, which is why I suggest to stay 20 to 30 degrees below the material's limit.

The above doesn't take into account any limitations of glue / sticker / carrier!

I'll get back to those in another post.


1.4 Smooth isn't smooth

G10 and G11 are not flat. They may seem flat, but they contain thousands of little ridges and valleys. Some can be felt by rubbing your finger over a plate, but sometimes these are so small that the plate almost appears mirror smooth. The top surface is defined by the manufacturing process (mostly the surface of the press being used) and the chemical reactions during curing.

The printed material needs something to hold on to. The seemingly flat G10 / G11 surface isn't flat. That's why you may have to use (very fine) sandpaper on old G10 / G11 plates to recondition them (and restore adhesion).

Compared to Textured PEI plates you could say these G10 / G11 plates have a micro-texture, but from a perspective of the printer and the slicer they're smooth (on an X1C the Aruco code would the the Smooth / High Temp code).

Check this page for more about textures on build plates.


1.5 Phenolic Resin vs. Epoxy Resin

Phenolic resin is the older stuff, colors typically ranging from dark yellow to red to brown. By adding colorants and other filler material other colors can be realized. It's brittle but hard, and can be readily machined. Cloth and paper are often used as filler and reinforcement (Bakelite).

Epoxies are newer, and are standard watermelon-green to yellow-green. They are often combined with glass fiber and carbon fiber matts to create strong, light-weight insulation panels.

Some Chinese sites mix the two up, but please DO NOT USE phenolic resin plates as they contain formaldehyde. Unless you like your fumes poisonous...


1.6 Fibers don't matter

It's not the used glass or carbon fiber that defines how hot a plate can be used, it's the epoxy used, as that is what's touching the filament.

The nozzle will never tough the fiber itself. It may touch the wiping area on a Bambu X1 / P1 machine, but not the plate surface. The extruded filament will touch the plate though, and thus the plate surface must be able to withstand the temperature of liquid filament for a certain amount of time.

So, fibers don't matter. Except perhaps in your diet 😎

If you study the spec sheets, you'll notice that even G11 / FR5 can't withstand prolonged exposure to the print temperature of even something like PLA! That these plates still work well is because this heating up is only locally and temporary.


1.7 Carbon

If neither nozzle nor filament never ever touch the fiber, then this also means that carbon plates are effectively a waste of money. The epoxy is more important than the fiber used.

Don't waste your money on carbon fiber build plates!


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