Storage of filament

Before we begin to discuss the various methods of storing the filament , let me describe the prime cause of why filament should be stored.

Why should we store filament?

Most of the thermoplastic materials used in 3d printer filaments are hygroscopic-substances which can absorb water molecules from the surroundings. Which means keeping your filaments out in the open environment can cause damage to the filament material.

Below are some of the effects which can occur due to moisture absorption by filament.

  •  Brittleness will increase
  •  Change in the diameter of filament
  •  Puffs of smoke, steam and sizzling sound can occur while extruding.
  •  Change in the melting point of filament.
  •  Change in the shape of filament.
Filament materials such as PLA, ABS, PVA and Nylon will absorb moisture though absorption rate in Nylon is less relatively. Moisture absorption rate is more in PLA when compared with ABS. It will not only effect the filament material but also will damage the printer by jamming the nozzle, and requiring high temperature for extrusion. 

Solution: Below are few techniques used for storing filament.

Vacuum bags or Ziploc bags: This technique is easy and works well for keeping the filament dry. Regular vacuum-sealed bags are generally used for keeping winter clothes in homes. It would be very beneficial using bags which have seal opening at the top. Remove the filament from the printer after use. Keep the filament inside the vacuum bag, using vacuum cleaner flush out the oxygen inside the bag. Then store the vacuum packed filament at appropriate place. Vacuum bags or Ziploc bags can keep moisture, odors, mildew and bugs away from filament.

Fig shows filament stored in vacuum bag.


Silica gel: Silica gel packs are available in different shapes and sizes. There are some silica gel packs with saturation indicators, which can be easily identified after saturation and can be reused by drying them in an oven. Place the filament in an airtight container with silica gel. They get saturated after absorbing all the moisture of the filament. Or use silica gel desiccants which are seen in new plastic filament packed inside vacuum sealed bags. Desiccants works fine when they are in a closed-system. Open the bag when you need to print and after use wrap it up in vacuum bag by dropping a few desiccants to absorb moisture in it.

Fig shows general silica gel packets which come along with filament spool packed.


Uncooked rice:  It works similar to silica gel. Store your filament inside a waterproof container with a smaller container full of uncooked rice in it, to absorb any moisture that does get in. Although rice has hygroscopic properties, it is not as effective as an industrially produced desiccant like silica-gel. Rice in comparison to silica-gel could be considered as a 'weak/mild' desiccant.