Chemistry:3D printing filament

Short description: Thermoplastic feedstock for 3D printers

3D printing filament in different colours with models created using the filament.

3D printing filament is the thermoplastic feedstock for fused deposition modeling 3D printers. There are many types of filament available with different properties.

Filament comes in a range of diameters, most commonly 1.75 mm and 2.85 mm, with the latter often being confused with the less common 3 mm.

Filament consists of one continuous slender plastic thread spooled into a reel.

Production

Commercially produced filament

Stacks of commercially produced filament which have been shrink-wrapped to protect the filament from moisture.

3D printing filament is created using a process of heating, extruding and cooling plastic to transform nurdles into the finished product. However, unlike a 3D printer, the filament is pulled rather than pushed through the nozzle to create the filament. The diameter of the filament is defined by the process that takes place after the plastic has been heated rather than the diameter of the extruder nozzle. A different force and speed is applied to the filament as it is pulled out of the extruder to define the width of the filament, most commonly 1.75 mm or 2.85 mm diameter.

The plastic nurdles are always white or clear. Pigments or other additives are added to the material before it is melted to create coloured filament or filament with special properties, e.g. increased strength or magnetic properties. Before the filament is extruded the nurdles are heated to 80 °C to dry it and reduce water content. The nurdles must be dried as many thermoplastics are hygroscopic and extrusion of damp plastic causes dimensional flaws (this is also the case when the finished filament is being printed). From there the nurdles are fed into a single screw extruder where it is heated and extruded into a filament. The diameter is often measured by a laser beam(not melting) as part of a quality control mechanism to ensure correct diameter of the filament. The filament is then fed through a warm water tank which cools the filament which gives the filament its round shape. The filament is then fed through a cold water tank to cool it to room temperature. It is then wound onto a spool to create the finished product.

DIY filament production

DIY filament production machines use the same method as FDM 3D printers of pushing the filament through the extruder to create the correct diameter filament. There are several DIY filament machines available as both open source plans and commercially available machines.

A food dehydrator can be used to remove water from hygroscopic materials at above 70 °C.

Use

The process of transforming 3D printing filament into a 3D model

1. The filament is fed into the FDM 3D printer.
2. The thermoplastic is heated past its glass transition temperature inside the hotend.
3. The filament is extruded and deposited by an extrusion head onto a build platform where it cools.
4. The process is continuous, building up layers to create the model.

Materials

Filament	Special Properties	Uses	Strength	Density (kg/m3)	Flexibility	Durability	Difficulty to print	Print Temperature (°C)	Bed Temperature (°C)	Printing notes
PLA	Easy to print Biodegradable, though only in very specific conditions	Consumer Products	1 Medium	1240	0 Low	1 Medium	0 Low	180 - 230	No heated bed needed or, 60-80C are recommended also
ABS	Durable Impact resistant	Functional Parts	1 Medium	1010	1 Medium	2 High	1 Medium	210 - 250	50 - 100
PETG (XT, N‑Vent)	More flexible than PLA or ABS Durable	All	1 Medium	1270	2 High	2 High	1 Medium	220 - 235	No heated bed needed
Nylon	Strong Flexible Durable	All	2 High	1020	2 High	2 High	1 Medium	220 - 260	50 - 100	Hygroscopic, keep sealed when not in use
TPE	Extremely flexible Rubber-like	Elastic Parts Wearables	0 Low		2 High	1 Medium	2 High	225 - 235	40	Print very slowly
TPU	Extremely flexible Rubber-like	Elastic Parts Wearables	0 Low		2 High	1 Medium	2 High	225 - 235	No heated bed needed	Print slowly
Wood	Wood-like finish	Home Decor	1 Medium	1400	1 Medium	1 Medium	1 Medium	195 - 220	No heated bed needed
HIPS	Dissolvable	Support structures when using ABS on a dual extrusion printer.	0 Low	1040	1 Medium	2 High	1 Medium	210 - 250	50 - 100
PVA	Dissolvable Water Soluble Biodegradable Oil Resistant	Support structures when using PLA or ABS on a dual extrusion printer.	2 High		0 Low	1 Medium	0 Low	180 - 230	No heated bed needed	Hygroscopic, keep sealed when not in use
PET (CEP)	Strong Flexible Durable Recyclable	All	2 High		2 High	2 High	1 Medium	220 - 250	No heated bed needed
PLA Metal	Metal Finish	Jewelry	1 Medium		0 Low	2 High	2 High	195 - 220	No heated bed needed	Use hardened nozzle
PLA Carbon Fiber	Rigid Stronger Than Pure PLA	Functional Parts	1 Medium		0 Low	2 High	1 Medium	195 - 220	No heated bed needed	Use hardened nozzle
Lignin (bioFila)	Biodegradable Stronger than PLA		1 Medium		0 Low	1 Medium	0 Low	190 - 225	55
Polycarbonate	Very strong Flexible Durable Transparent Heat Resistant	Functional Parts	2 High	1180 – 1200	2 High	2 High	1 Medium	270 - 310	90 - 105	Use enclosed heated chamber at ambient temperature of around 60 °C
Conductive (usually a graphite-plastic blend)	Conductive	Electronics	1 Medium		1 Medium	0 Low	0 Low	215 - 230	No heated bed needed	Use hardened nozzle
Wax (MOLDLAY)	Melts Away	Lost wax Casting	0 Low		0 Low	0 Low	0 Low	170 - 180	No heated bed needed
PETT (T‑Glase)	Strong Flexible Transparent Clear	Functional Parts	2 High		2 High	2 High	1 Medium	235 - 240	No heated bed needed
ASA	Rigid Durable Weather Resistant	Outdoor	1 Medium		0 Low	2 High	1 Medium	240 - 260	100 - 120
PP	Flexible Chemical Resistance	Flexible Components	1 Medium	1040	2 High	1 Medium	2 High	210 - 230	120 - 150
POM, Acetal	Strong Rigid Low Friction Resilient	Functional Parts	2 High		0 Low	1 Medium	2 High	210 - 225	130
PMMA, Acrylic	Rigid Durable Transparent Clear Impact Resistant	Light diffusers	1 Medium		0 Low	2 High	1 Medium	235 - 250	100 -120
Sandstone (LAYBRICK; styled plastic)	Sandstone Finish	Architecture	0 Low		0 Low	0 Low	1 Medium	165 - 210	No heated bed needed
Glow-In-The-Dark plastic	Phosphorescence	Fun	1 Medium		1 Medium	1 Medium	0 Low	215	No heated bed needed	Use hardened nozzle
Cleaning	Cleaning	Unclogging of Nozzles	N/A		N/A	N/A	0 Low	150 - 260	No heated bed needed
PC-ABS	Rigid Durable Impact Resistant Resilient Deflecting Heat	Functional Parts	1 Medium		0 Low	2 High	2 High	260 - 280	120
Magnetic (PLA blend)	Magnetic	Fun	1 Medium		1 Medium	1 Medium	2 High	195 - 220	No heated bed needed
Color Changing (plastic blend)	Thermochromism	Fun	1 Medium		1 Medium	1 Medium	0 Low	215	No heated bed needed
nGen (co-polyester)	Similar to PETG Heat Resistant Transparent	All	1 Medium		2 High	2 High	1 Medium	210 - 240	60
TPC	Extremely Flexible Rubber-Like Chemical resistant Heat resistant UV light resistant	Elastic Parts Outdoor	0 Low		2 High	1 Medium	2 High	210	60 - 100
PORO-LAY	Partially Water Soluble	Experimental	0 Low		2 High	1 Medium	0 Low	220 - 235	No heated bed needed
FPE	Flexible	Flexible Parts	0 Low		2 High	2 High	1 Medium	205 - 250	75
PEI	Heat Resistant Strong Flame Performance	Functional Parts	2 High	1270	1 Medium	2 High	1 Medium	340 - 380	180 - 200	Use enclosed heated chamber at 220 °C

The process of turning 3D printing filament into a 3D model