Tuesday, May 31, 2016

Dealing with Filament Aging

This post is relevant to all 3D printers using PLA, Nylon or ABS.  But, it may be increasingly relevant to Cube printer owners.  And, that is the subject of treating and storing filament in a way that provides the least difficulties during printing.

At the YouthQuest Foundation we have scores of Cube printers with an average inventory of 3 cartridges for each printer.  The printers are not used on a daily basis.  So, learning why and how filament degrades over time has been extremely important for us.

The problem came to the fore when 3D Systems first donated a number of 2nd Gen printers,   The printers had been in inventory for a number of years.  Even though the supplied filament was in sealed bags with packets of drying agent, all of the filament was brittle and easily clogged the printers.  Fortunately, 3D Systems replaced all the filament.  But, even this, too, showed some tendency to brittleness.  With this in mind, we began to explore exactly why we were seeing what we were seeing.  More importantly, we needed to find a solution that would minimize damage while the filament was being stored.

We THINK we have come up with the solution.  It involves combining a dehydrating system to proactively remove existing moisture from filament and a sealed storage system with a robust dehydration system.

DEHYDRATION SYSTEM

Since the problem of moisture affecting filament is common to ALL 3D printers, there are a number of new dehydration systems being developed specifically designed for filament.  But, the most interesting ones have yet to be released.  So, we looked for alternatives.  And, they came in the form of food dehydrators.  Here is the one that we recommend... the NESCO FD77DT Digital Food Dehydrator:

Nesco FD77DT Food Dehydrator

It is important to purchase a digital dehydrator that allows you to set a precise time and temperature as different types of filament require different times and temperatures.  This model can be found for under $80.   One of the main reasons we like this brand and model is the way air is distributed ACROSS each layer.  We open the Cube2 cartridges and only put the cardboard cartridges in the dehydrator.  For Cube 3 cartridges, we open the cover and put the uncovered base and reel in the dehydrator.  For our initial tests, we set it at 45C degrees and run it for 4 hours.  This could be refined as we gain more experience.

STORAGE POLICY

From now on, we will  no longer leave filament in the printers between print sessions... even if it only means leaving it in the printer overnight!  The only exception to this are the CubePro printers which we now treat as closed filament storage systems with their own dehydrator.

STORAGE SYSTEM

Some time ago, we had decided to store filament in large plastic boxes with sealed tops and single use moisture remover.  But, it turns out that using a simple 5 gallon bucket with a special sealed screw-on top is an even better solution.  We go right from the food dehydrator into a bucket.

5 Gallon Bucket

We pair the bucket with a special sealed screw-on top.  The Gamma Seal top is the key to the ability to ensure a moisture barrier.  Because we wanted to color code our storage, we have purchased both buckets and tops from both Home Depot (Red/White bucket and Black top) and Lowes (Blue bucket and white top).

Gamma Seal Top
The last part of the storage system is a cost effective way to ensure the lowest moisture levels in the bucket.  We could use packets, as we previous used with the plastic boxes.  But, we found what we believe to be a MUCH better solution, the Lagute Adenium L-A01 Renewable Wireless Mini Dehumidifier. 

Lagute Mini-Dehumidifier
The beauty of this system is two-fold.  First, it is a perfect size.  And, secondly, there is a window that allows you to determine when the beads in the dehumidifier need to be recharged.  To recharge the system you simply plug it in over night!  We use the same dehumidifier inside the CubePro.

So far, it looks like the dehumidifier takes the relative humidity under 22% in a single day.  It may ultimately go lower if I could only resist opening the bucket to check it!  :)

MODIFYING THE DRYING RACKS

In order to fit a cartridge into the food dryer, the standard racks with have to be alternated with racks that have been cut to remove the grill.  But, extra FD-77DT racks are relatively inexpensive and can be purchased locally at Bed Bath & Beyond.  I believe it cost about $14 for a set of two extra racks.

I would not buy the actual  NESCO DEHYDRATOR  model that can be found on the shelves in Bed, Bath & Beyond Stores.  It will work; but, it has no off-on switch or timer.  Buy online to get the digital model.  Sears seemed to have the lowest price.  But, shipping is not as fast as Amazon.

I fully expect that using these tools we may be able to save filament we otherwise might have had to discard.  But, at the very least it is going to protect our future filament investments.


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