Polycarbonate vs ABS Injection Molding: A Comparative Guide

Polycarbonate vs ABS Injection Molding: What’s the Difference?

Polycarbonate and ABS (acrylonitrile butadiene styrene) are two of the most widely used engineering thermoplastics for injection molding applications across industries. But what sets them apart and when is one preferred over the other?Polycarbonate is commonly used for injection molding due to its strength and transparency. More details on polycarbonate injection molding. ABS is a popular plastic for injection molded parts and products. Read more about the ABS injection molding process.

This guide provides an in-depth comparison between polycarbonate and ABS injection molding in terms of properties, molding characteristics, end-use applications, and material pricing.

Overview of Polycarbonate and ABS Plastics

Polycarbonate (PC) and ABS are both amorphous high-performance thermoplastics used for injection molding.

Polycarbonate

• Extremely impact resistant
• Optical clarity
• Heat resistance up to 140°C
• Low smoke & toxicity

ABS

• High impact strength
• Good chemical resistance
• Heat resistance up to 80°C
• Typically opaque except for transparent grades

Key Property Differences

Here's how the properties of polycarbonate and ABS stack up:

As the data shows, polycarbonate demonstrates superior mechanical properties like tensile and flexural strength. It also has much greater impact resistance compared to ABS.

On the other hand, ABS offers better chemical resistance, more color and opaque options, and costs comparatively less.

Molding Parameter Differences

Polycarbonate and ABS have the following key differences when injection molding:

Melt Temperature

• Polycarbonate: 280 - 320°C
• ABS: 220 - 280°C

Mold Temperature

• Polycarbonate: 70 - 120°C
• ABS: 40 - 80°C

Shrinkage

• Polycarbonate: 0.5 - 0.7%
• ABS: 0.3 - 0.8%

Clamping Pressure

• Polycarbonate: 56 - 84 MPa
• ABS: 35 - 70 MPa

Polycarbonate requires higher melt and mold temperatures. It also needs higher clamping pressure than ABS due to higher viscosity. Appropriate parameter adjustments are required when switching between the two resins.

Typical Applications

Polycarbonate

Medical devices, electrical components, machinery parts, signages, transparent sheets

ABS

Consumer appliances, electronics housings, automotive components, medical devices, protective gear

Polycarbonate is widely used when high strength, heat resistance, and optical clarity are needed. ABS provides a good balance of mechanical, chemical and thermal properties at a lower cost for a diverse range of applications.

Cost Comparison

Polycarbonate: $2.0 - $3.5/lb

ABS: $1.5 - $2.2/lb

The average price per pound of ABS is around 20-40% lower than polycarbonate resin. However, the final part cost depends on additional factors like raw material needed, cycle time, tooling, and post-molding operations.

Which is Better?

So which should you choose - polycarbonate or ABS injection molding? Here are some broad guidelines:

• For strength and heat resistance, polycarbonate is better
• For chemical resistance and opaque finishes, ABS is preferable
• For cost-sensitivity, ABS provides more value
• For medical and optical clarity needs, polycarbonate works better

The ideal choice depends on your specific application requirements and priorities regarding properties, aesthetics, and budget. Expert molders can provide material recommendations based on your product performance needs.

Conclusion

When comparing polycarbonate vs ABS injection molding, the key differences lie in mechanical strength, heat and chemical resistance, optical properties, processing requirements and raw material pricing. Polycarbonate demonstrates superior strength and clarity. ABS offers better chemical resistance at lower cost but reduced strength. With their diverse properties, both thermoplastics find wide use for varied applications across industries. Consider product performance needs, cost targets and other factors to choose the right material for a particular injection molding application.