What Is the Difference Between ABS and PC Injection Molding?

In the world of plastic manufacturing, injection molding is one of the most versatile and widely used processes for creating complex plastic parts with precision and efficiency. Among the many materials available for this process, ABS (Acrylonitrile Butadiene Styrene) and PC (Polycarbonate) stand out for their balance of performance, cost, and versatility.

While both are thermoplastic polymers commonly used in industrial and consumer applications, they differ significantly in terms of mechanical properties, processing requirements, and end-use performance. This article explores the key differences between ABS and PC injection molding, helping engineers, designers, and buyers make informed decisions for their projects.

1. Overview of ABS and PC Materials

ABS (Acrylonitrile Butadiene Styrene)

ABS is a terpolymer made from three monomers: acrylonitrile, butadiene, and styrene. Each component contributes distinct properties:

• Acrylonitrile: adds chemical resistance and rigidity

• Butadiene: enhances impact strength and toughness

• Styrene: provides surface gloss and ease of processing

This combination makes ABS one of the most widely used plastics for automotive parts, consumer electronics housings, toys (like LEGO bricks), and appliance covers.

PC (Polycarbonate)

Polycarbonate is an amorphous thermoplastic known for its exceptional impact resistance, optical clarity, and heat resistance. It is often used when transparency and strength are crucial, such as in safety goggles, automotive headlight lenses, medical devices, and electrical housings.

2. Material Properties Comparison

Property	ABS	PC (Polycarbonate)
Appearance	Opaque, easy to color	Transparent or translucent
Impact Strength	Good	Excellent (superior to ABS)
Heat Resistance	Moderate (up to 80–100°C)	High (up to 130°C or more)
Tensile Strength	Moderate	High
Flexibility	More rigid	More flexible under stress
Weather Resistance	Poor (can degrade under UV)	Good (better UV and environmental   resistance)
Cost	Lower	Higher
Density	~1.04 g/cm³	~1.20 g/cm³

In summary, ABS is more economical and easier to process, while PC offers higher performance in demanding environments.

3. Processing Differences in Injection Molding

a. Molding Temperature

• ABS: Melt temperature ranges between 200–250°C, and mold temperature between 40–80°C.

• PC: Requires higher melt temperatures of 260–320°C, and mold temperature between 80–120°C for better surface finish and dimensional stability.

This means PC requires more energy and careful thermal control during processing.

b. Drying Requirements

Both materials must be dried before molding, but PC is much more moisture-sensitive.

• ABS: Typically dried at 80°C for 2–4 hours.

• PC: Requires drying at 120°C for 3–4 hours.

Inadequate drying of PC can lead to bubbles, splay marks, or reduced mechanical properties.

c. Mold Design Considerations

• ABS: Flows easily and fills molds well, allowing for complex shapes and thin walls.

• PC: Has higher viscosity, so it needs higher injection pressure and well-designed vents and runners.

Mold materials must also withstand PC’s higher processing temperatures.

4. Applications of ABS vs PC Injection Molding

ABS Common Applications

• Computer keyboards, printers, and electronic housings

• Automotive dashboards and interior trim

• Tool handles and protective casings

• Household appliances (vacuum cleaners, hair dryers)

ABS’s balance between strength, cost, and surface finish makes it ideal for everyday consumer products.

PC Common Applications

• Optical lenses and lighting covers

• Electrical and electronic enclosures

• Safety helmets, shields, and goggles

• Automotive headlamp lenses and medical components

PC is chosen when high strength, heat resistance, or optical clarity are priorities.

5. ABS vs PC: Which Is Better for Your Project?

Choosing between ABS and PC depends on your performance requirements, cost constraints, and design goals.

Choose ABS if you need:

•  A cost-effective solution

•  Easy processing and molding

•  Good surface finish and aesthetic appeal

•  Moderate mechanical and thermal performance

Choose PC if you need:

•  Superior impact and heat resistance

•  Optical transparency

•  Dimensional stability under load

•  Resistance to UV and weathering

For applications that demand both toughness and ease of processing, PC/ABS blends are also a popular compromise, offering improved impact resistance over ABS and better moldability than pure PC.

6. Cost and Sustainability Considerations

From a cost perspective:

• ABS is more affordable both in raw material and processing.

• PC costs more due to higher resin prices and energy requirements.

However, PC parts often last longer and perform better in extreme conditions, which can reduce replacement costs over time.

In terms of sustainability, both plastics can be recycled (typically under resin codes 7 for PC and 9 for ABS), but PC recycling is less common due to its high-end applications and potential contamination with additives.

7. Summary Table: Quick Comparison

Aspect	ABS Injection Molding	PC Injection Molding
Ease of Molding	Easy	More challenging
Cost Efficiency	High	Moderate to low
Strength & Impact	Good	Excellent
Heat Resistance	Medium	High
Surface Finish	Smooth, glossy	Clear or high polish
Applications	Consumer, automotive interiors	Optical, safety, medical
Drying Sensitivity	Low	High

Conclusion

Both ABS and PC are excellent materials for injection molding, but they cater to different needs.

If your project values cost, easy processing, and aesthetics, ABS is a reliable choice.

If your design prioritizes strength, clarity, and durability, PC is the better option.

Understanding these differences helps manufacturers choose the right material from the start — optimizing performance, cost, and manufacturability for their specific product.