ABS, ASA, and HIPS: Understanding the Differences and Choosing the Right Material

ABS (Acrylonitrile Butadiene Styrene) and ASA (Acrylic Styrene Acrylonitrile) and HIPS (High Impact Polystyrene) include two of the most widely used materials in additive manufacturing and the underdog HIPS. While each material has its own unique properties and applications, it's important to understand the differences between them to choose the right material for your needs. In this blog post, we'll take a closer look at ABS, ASA, and HIPS, and help you understand which material is right for you.  

Advantages of ABS  

1. High Strength: ABS is known for its high strength, making it ideal for applications that require a strong, durable printed part. This makes it a popular choice for functional parts such as automotive components, electrical components, and toys.  
    
2. Good Impact Resistance: ABS has good impact resistance, making it a suitable option for applications where the printed part will be subjected to impact and stress.  
    
3. Post processing: ABS can be vapor smoothed using Acetone to produce a smooth surface finish with high gloss. It can also be machined, tapped, sanded and painted. 

Advantages of ASA  

1. UV Resistance: ASA has excellent UV resistance, making it ideal for applications where the printed part will be exposed to direct sunlight or other UV light sources.  
    
2. Weather Resistance: ASA has good weather resistance, making it a suitable option for outdoor applications where the printed part will be exposed to the elements.  
    
3. Good Mechanical Properties: ASA has good mechanical properties, including high strength and impact resistance, making it ideal for functional parts.  
    
4. Vapor Smoothing: ASA can be vapor smoothed using Acetone to produce a smooth surface finish with high gloss. It can also be machined, tapped, sanded and painted. 

Advantages of HIPS  

1. Lightweight: HIPS is a lightweight material, making it ideal for applications where weight is a critical factor. This makes it a popular choice for packaging and lightweight functional parts.  
    
2. Good Printability: HIPS is known for its good printability, making it a suitable option for applications where the printed part needs to have a smooth and consistent surface finish.  
    
3. Easy to Sand and Paint: HIPS is easy to sand and paint, making it ideal for applications where the printed part needs to be finished with a smooth surface or painted to match specific colors.  
   
4. Low Hardness: HIPS has a low hardness (Rockwell R – 55). 
    
5. Low Warping and Shrinking: HIPS has low warping, making it a suitable option for applications where the printed part needs to have a consistent shape and size, even when exposed to high temperatures.  
    
6. Post processing: HIPS can also be machined, tapped, sanded and painted. It also features a matte look making it ideal for visual parts. 
    
7. Support Material: HIPS is often used as a support material when printing with ABS or ASA, due to its dissolvability in Limonene.  
   
   

In conclusion, ABS, ASA, and HIPS each have their own unique properties and applications, and the right material for your needs will depend on your specific requirements. ABS is a strong and durable material that is ideal for functional parts and can be vapor smoothed with Acetone for a high-quality glossy surface finish. ASA is ideal for outdoor applications and functional parts due to its UV and weather resistance and good mechanical properties and can also be vapor smoothed with Acetone. HIPS is a lightweight, cost-effective material that is ideal for packaging applications or presentation items.