SUPPORT FILAMENTS

There is one law that FDM 3D printing has not yet been able to transcend: gravity. Yet.

Generally speaking, whenever a print has an overhang of over 45 degrees, support is required. Complex structures with a single extruder FDM printer typically means than you are using the same filament for both support and primary structure. Pending the filament and settings used, support structures to can fuse into the print and post-processing can prove onerous and mar the aesthetics of the final print.

Dual extruder printers offer the potential of using secondary, support filaments detailed below. Support filaments are designed specifically for the purpose of supporting complex builds and being more easily removed.


PVA – Polyvinyl Alchohol

PVA in the everyday world is used as glue or as the soluble sheaths for laundry detergent balls.

In the 3D printing world, PVA takes on a whole different role. It is often used with multi-extruder FDM 3D printers as a support material. The most useful feature of PVA filament is its ability to dissolve in water. This can mean a reduction in post processing and ugly marks left on the print after the support material is removed.

PVA generally works very well with PLA filaments since it requires same operating conditions such as the desired temperature. It can work with ABS, but it is not recommended since ABS does not bond well to PVA. A better support for ABS is HIPS, detailed below.

Parts printed with PVA supports usually need to be placed in water for a few hours (depending on the manufacturer’s specifications), until all of the PVA is dissolved. Because PVA typically dissolves into Polyvinyl Acetate, you typically end up with a glue-like film that needs to be rinsed off the component.

PRINT SETTINGS AND CONSIDERATIONS

  • 180° – 210° Celsius extruder temperature
  • 20° – 50° Celsius build platform temperature
  • PVA is very stringy, so adjusting other settings like print speed and retraction rate may be required to avoid contaminating the print.

POST PROCESSING NOTES: Just like there are different chemical compositions for other thermoplastics, the same is true for PVA. So while all PVA’s will dissolve in water, the amount of time may vary

PVA BRANDS: eSun, Sainsmart, Polymaker

PRICING: There is a pretty high demand for PVA filaments so pricing typically starts at right around CDN$40/spool.


HIPS – Hi Impact Polystyrene

In the commercial world, high impact polystyrene (HIPS) – a copolymer that combines the hardness of polystyrene and the elasticity of rubber – is commonly found in protective packaging and containers, like CD cases. In the world of 3D printing, HIPS can be used to play a very different role. When paired with ABS in a dual extrusion printer, HIPS is an excellent support material.

For dual extrusion printing with HIPS, simply crank the supports to the max and fill any gaps in your design with HIPS 3D printer filament. Immersing the finished print in limonene will strip away the HIPS leaving your final product behind.

Unfortunately to use HIPS as a support material limits you to printing your actual part from ABS. Other 3D printer filament materials will be damaged by the limonene. Handily, HIPS and ABS print well together in any case, being of similar strength, stiffness, and requiring a comparable print temperature.

In fact, despite its primary use as a support material, HIPS is a decent 3D printer filament in its own right. It is stronger than both PLA and ABS, warps less than ABS, and can easily be glued, sanded, and painted.

PRINT SETTINGS AND CONSIDERATIONS

  • 225° – 250° Celsius extruder temperature
  • 100° – 110° Celsius build platform temperature

POST PROCESSING NOTES: HIPS can be dissolved using d-Limonene, which is a chemical found in the rinds of citrus fruits.

HIPS BRANDS: eSun, GizmoDorks, Filatech

PRICING: HIPS filament averages at CDN$35/spool, pending quality, but you also need to acquire the d-Limonene solvent. D-Limonene solvent averages $25/gallon.


Breakaway Filaments

Like PVA and HIPS, breakaway filaments are designed to support prints while being printed. Unlike PVA and HIPS, break-away filaments do not dissolve but are rather designed to snap or break off when the print is complete.

The exact chemical composition of breakaway filaments may vary but they are typically a mix of polyurethane and polylactic acid. Designed to tear or strip away without leaving residue, breakaway filaments work well for a much wider range of filaments ranging from PLA to nylon.

PRINT SETTINGS AND CONSIDERATIONS

  • 220° – 230° Celsius extruder temperature
  • 95° – 105° Celsius build platform temperature.

POST PROCESSING NOTES:

BREAKAWAY BRANDS: Polysupport, Ultimaker

PRICING: Average CDN$50/spool


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