3D printing filament is the

thermoplastic A thermoplastic, or thermosoft plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains associate ...

feedstock A raw material, also known as a feedstock, unprocessed material, or primary commodity, is a basic material that is used to produce goods, finished goods, energy, or intermediate materials that are feedstock for future finished products. As feedst ...

for fused deposition modeling

3D printers 3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer co ...

. 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

3D printing filament is created using a process of heating, extruding and cooling plastic to transform

nurdles Nurdle or Nerdle may refer to: *Nurdle (bead), a pre-production microplastic pellet about the size of a pea *Plastic resin pellet pollution, nurdles as marine debris *Nurdle, a term used in cricket; see List of cricket terms * ''Nerdle'' (game), a ...

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 Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

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 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 Tomato slices ready to be dried in a convection-type food dehydrator. In this model, multiple trays can be stacked on top of each other and warm air flows around the food. A food dehydrator is a device that removes moisture from food to aid in its ...

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 # The filament is fed into the FDM 3D printer. # The thermoplastic is heated past their

glass transition The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubb ...

temperature inside the hotend. # The filament is extruded and deposited by an extrusion head onto a build platform where it cools. # The process is continuous, building up layers to create the model.

Materials

References

{{reflist Plastics 3D printing