HIPS 3D Printing Filament Explained: Materials, Properties & Uses

HIPS (High Impact Polystyrene) is made by combining polybutadiene rubber and pure polystyrene. HIPS is a thermoplastic material that possesses some unique characteristics not shared by most filaments, including: low hygroscopicity; solubility in d-limonene (a chemical solvent); and good impact resistance. HIPS has the advantage of being cost-effective, quick-printing, and durable. As an added benefit, it can serve as a support material for ABS 3D-printed parts.

HIPS was created by Johann Eduard Simon, a German apothecary. The resin of a sweetgum tree called storax was taken and synthesized. The result of the synthesis was an oily substance. Some days later, to his surprise, the substance thickened and became jelly-like. This substance he named styrene oxide. However, it took almost a century before the product was utilized in industrial applications.

Currently, HIPS is used in a wide variety of industries to produce consumer products, including: toys, electronic components, bicycle trailers, and food packaging. This article will discuss the use of HIPS for 3D printing in detail: its composition, properties, limitations, and applications, as well as some tips for successful printing with HIPS filaments.

What Is HIPS 3D Printing?

While HIPS filament can be used alone to print 3D parts, it is mainly used to print easily removed supports for overhanging structures in parts printed from other plastics. HIPS is usually paired with ABS as the main print material. Support structures printed with HIPS can be removed from the main printed component by dissolving them in d-limonene without sanding or scrubbing. This characteristic is why it is used as a support structure with ABS: ABS for the main printed part, and the easily dissolvable HIPS for temporary print supports.

To learn more, see our How Do 3D Printers Work guide.

What Is the Composition of HIPS Filament?

HIPS combines the chemical attributes of polybutadiene rubber and pure polystyrene. Polybutadiene rubber is known for its elasticity. Pure polystyrene, on the other hand, is known for its hardness. The result of this combination is a solid material that does not break easily because of its relatively high tensile strength. 

To prepare HIPS, butadiene is selectively polymerized in styrene. This process is achieved in the presence of a chemical catalyst called neodymium bis(2-ethylhexanol) phosphonate/diisobutyl aluminum hydride/diethylaluminum chloride.  The prepolymer solution should have high cis-1,4 and low styrene content of 96.6% and 1.01% respectively. The resulting chemical solution is polymerized again with styrene, but this time in a thorough way.

What Are the Properties of HIPS Filament?

Some of the properties of HIPS include:

1. HIPS is easily formable and machinable and works well with a range of adhesives.
2. It is durable and possesses good impact resistance.
3. It is a dissolvable support material that is soluble in d-limonene.
4. HIPS is food-safe and therefore can be used as a packaging product in the food and beverage industries.
5. One of the beneficial characteristics of HIPS is its ease of storage. Unlike most filaments, which absorb moisture when exposed to air (they are hygroscopic), HIPS remains stable when exposed to moisture.
6. The melting temperature falls in the range of 220-250 °C.

Comparison of HIPS Filament Properties

Table 1 below compares the properties of HIPS filaments with other filament materials: