Acrylonitrile Butadiene Styrene, or simply “ABS”, is a thermoplastic. It technically belongs to the polystyrene family of polymers. Like all thermoplastics, Acrylonitrile Butadiene Styrene responds very well to heat. It melts quickly when heated, so molding it or extruding it is very easy. That’s why ABS is used every day in fused deposition modelling (FDM) - a popular 3D-printing technique. Acrylonitrile Styrene Acrylate, or “ASA”, is a cousin of ABS.
ASA belongs to the polystyrene family of polymers like ABS. It was developed as a better alternative to ABS for 3D printing applications. Although both ABS and ASA have similar mechanical properties/structures, unlike ABS, ASA lacks double bonds. That means it’s more resistant to UV radiation, weathering, heat, and chemical damage.
Benefits of Using this Material
Both ABS and ASA come in sheets, films, resins, or filaments. They’re primarily used in 3D printing. ABS also offers a variety of other manufacturing uses like – extrusion blow molding, thermoforming, structural foam molding, and injection molding. Users can even co-extrude ASA filaments alongside other polymers.
Like most thermoplastics, ABS and ASA have high melting points and low glass transitions. These properties make them highly suitable materials for multiple industrial applications. Some common uses of ABS include –
1. Manufacturing medical Supplies
2. Manufacturing auto body parts
3. Manufacturing protective headgear
4. Manufacturing computer components
5. Manufacturing phone components
6. Manufacturing pipes and fittings
Both Acrylonitrile Styrene Acrylate and Acrylonitrile Butadiene Styrene are suitable for these applications because they have the following properties –
1) High impact resistance
2) Heat resistance
3) Shock absorbency
4) Scratch resistance
Both ASA and ABS are cheaper than Copper, Nickel, and other metals used to make pipes, fittings, or product components. But, they’re more expensive than other plastics. However, these added costs don’t matter to manufacturers because other plastics don’t offer the benefits these thermoplastics provide.
Is It Safe to Use?
Yes. Both Acrylonitrile Styrene Acrylate and Acrylonitrile Butadiene Styrene are pretty harmless to humans. They don’t contain carcinogens. No serious health effects have been linked to exposure to these thermoplastics. The safety of these thermoplastics makes them extremely popular among 3D-printing enthusiasts and injection molding experts.
Polystyrene and Styrene Copolymers
Most of the thermoplastics you see in the market today have evolved from styrene-based polymers. The polystyrene family of polymers includes - polystyrene (PS), acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile copolymer (SAN), and rubber modified PS. ABS contains 25% acrylonitrile and 20% polybutadiene rubbers (by weight).
Acrylonitrile Styrene Acrylate is produced by copolymerizing acrylonitrile and styrene. Manufacturers add grafted acrylic ester elastomers (in powder form) to the mix during the copolymerization process to create ASA.
How is Acrylonitrile Butadiene Styrene made?
ABS is manufactured using a process called polymerization. Manufacturers use three ingredients to make ABS – styrene, acrylonitrile, and polybutadiene. They get the styrene monomer by putting ethyl benzene through “de-hydro-generation.” Then, they fuse propylene and ammonia to make the synthetic monomer called acrylonitrile.
Butadiene is a petroleum hydrocarbon that is a catalyst. ABS is made by polymerizing the first two ingredients in the presence of polybutadiene. Manufacturers essentially mix materials that don’t typically combine to produce ABS. ABS is a reusable and recyclable material. So, expect the ABS you purchase from the store to contain high percentages of recycled materials.
Acrylonitrile Styrene Acrylate Properties and Mechanical Specifications
ASA and ABS plastics have similar properties. But, Acrylonitrile Styrene Acrylate is by far the stronger of the two. Some of ASA’s most valuable properties include –
1. Strength and high impact
2. Wear and tear resistance
3. UV resistance
4. Ability to withstand extremely high/low temperatures
5. Resistance to weak acids, alkalis, oils, saturated hydrocarbons, and aqueous salt solutions
Here are ASA’s chief mechanical properties –
1. Tensile Strength: 4750PSI
2. Compressive Yield Strength: 10900PSI
3. Compressive Modulus: 297KSI
4. Flexural Modulus: 287KSITensile Strength at Break: 4630PSI
Use this guide if you’re considering using ABS or ASA for your next 3D printing or injection molding projects.