[nb_098 (OP)]

Hello everyone, I am currently researching the feasibility of applying AM in production of fiber optic cables. Currently it is quite labour intensive, and automation provided by the 3d printers would drastically lower the costs, which is quite vital in our 5G rollout era. I am thinking of using industrial SLS printers and would experiment with turning Silicon dioxide (i.e. powder form) into fiber optics (core & cladding). Also, a DLP 3D Printer could be used, I am still deciding at the moment. I am quite eager to learn, so I would love your feedback on this idea!

[evan_au]

The manufacture of optical fiber itself is quite automated, routinely producing lengths of fiber many kilometers long, and with manufacturing tolerances within 1 millionth of a meter (μm). Optical loss is around 0.1 dB/km.

Traditional Additive Manufacturing (AM) uses plastics which have extremely high optical attenuation, and cannot place materials accurate to 1μm. Producing something kilometers long by additive manufacture does not sound practical.
http://www.madehow.com/Volume-1/Optical-Fiber.html

However, there are many plastic components used with optical fibers such as plugs and sockets, which do not carry the light themselves, but merely bring the light-carrying optical fibers into alignment. Tolerances are looser here, perhaps 10μm, but that is still a stretch for traditional AM. For mass-produced components, injection-moulding will be cheaper and more accurate.

I think you need to find an application which requires many low-volume components with unique shapes in close proximity, where accurate alignment is not so critical.

There has been discussion of using optics on Integrated Circuits (IC) instead of copper or aluminium wires. But here the problem is reversed - IC technology now has a resolution of 0.01 μm, but the size of the optical components at 10-50μm is too large... 

[science-raven]

Genious idea!!! MIT and others are 3D printing glass... I would link it but i am not allowed to post links of the forum.

except that... light can't go around bends in glass and 3D printing is all about bends... What do you think of that then?!

I have spent 6 page refreshes to post this message, so it leads me to conclude that the html formum bb script is completely impractical and low quality!

[Bored chemist]

. light can't go around bends in glass

Yes it can.
That's the whole point of optical fibres.

[vhfpmr]

What puzzles me about 3D printing is why the components have any strength. My intuition keeps telling me that if your squirt a layer of molten plastic on a layer that's already cooled you'll get poor adhesion at the boundary, just like pouring concrete in more than one batch.

[evan_au]

molten plastic ..., just like pouring concrete

The type of thermoplastic used in 3D printers can be reversibly softened by just heating it. When you apply an extra layer of hot molten plastic, it heats the adjacent layer, and melts into it, providing a strong bond (bearing in mind that the plastic is not particularly hard).

In contrast, wet cement hardens in an irreversible reaction where the lime reacts with the water. If you put on another layer after a week setting, it does not soften the old layer, producing a very weak bond between the layers.
https://en.wikipedia.org/wiki/Concrete#Curing

[Petrochemicals]

molten plastic ..., just like pouring concrete

The type of thermoplastic used in 3D printers can be reversibly softened by just heating it. When you apply an extra layer of hot molten plastic, it heats the adjacent layer, and melts into it, providing a strong bond (bearing in mind that the plastic is not particularly hard).

Just out of interest how does everyone think long continuous runs of material are made? Some sort of ductile bank of material  ejecting  a thinner one sounds a lot like  3d printing or copper drawing.

molten plastic ..., just like pouring concrete

In contrast, wet cement hardens in an irreversible reaction where the lime reacts with the water. If you put on another layer after a week setting, it does not soften the old layer, producing a very weak bond between the layers.
https://en.wikipedia.org/wiki/Concrete#Curing

How it should be done.

https://www.engineersdaily.com/2014/04/how-to-bond-new-concrete-to-old-concrete.html?m=1

[evan_au]

How [concrete bonding] should be done.

It was apparent in the pictures, but I didn't see it in the text: The best way to bond two layers of concrete is by using reinforcing rods, where the reinforcing rods of the upper layer are bonded to the reinforcing rods of the lower layer.

[Petrochemicals]

How [concrete bonding] should be done.

It was apparent in the pictures, but I didn't see it in the text: The best way to bond two layers of concrete is by using reinforcing rods, where the reinforcing rods of the upper layer are bonded to the reinforcing rods of the lower layer.

It doesn't work if you are trying to repair patches on in place structures, the metal work is already in place.  Basically the gist of it is surface preparation back sound rough bondable  concrete with sufficient.

[JesWade21]

This is not going to happen right now. We can barely get glass clear enough to make fibre optics work by hand, let alone add all of the failure points of an additive manufacturing process. There are far too many variables, and the process must be tightly controlled. Perhaps I'm being overly pessimistic, but I don't see how additive manufacturing can accomplish this.

Fiber is traditionally made by drawing out glass I to longer, thinner strands, with a LOT of tempering and other processes along the way.

Don't even get me started on the fiber terminations...