Acrylonitrile Butadiene Styrene (ABS) plastic is a thermoplastic polymer that is commonly used in injection molding applications across a variety of industries. As one of the most versatile engineering thermoplastics available today, ABS offers an exceptional balance of strength, rigidity, and toughness.
But what exactly makes ABS well-suited for injection molding? As a professional plastic injection molding manufacturer, I will share a detailed look at how ABS plastic can be injection molded to create durable parts and products.
What Is ABS Plastic?
ABS plastic is a terpolymer created by polymerizing styrene and acrylonitrile in the presence of polybutadiene. The result is a lightweight and rigid thermoplastic material that exhibits high impact resistance and mechanical strength. It also stands up well to corrosive chemicals and physical stress.
Some key properties of ABS include:
- High tensile strength
- Good dimensional stability
- Heat and chemical resistance
- Impact strength and toughness
- Colorability and gloss potential
The acrylonitrile component gives ABS thermal stability and chemical resistance. The polybutadiene provides toughness, especially at low temperatures. And the styrene contributes rigidity, hardness, and ease of processing.
Can ABS Plastic Be Injection Molded?
Yes, ABS plastic is well-suited for injection molding applications across automotive, consumer appliances, business equipment, medical devices, and more. Its amorphous structure plasticizes readily at relatively low temps while providing high strength, rigidity, and chemical/temperature resistance once cooled and solidified. Proper parameter configuration enables creation of durable and high precision ABS injection molded parts.
Why Use ABS Plastic for Injection Molding Parts?
There are several key reasons why ABS injection molding is so widely used across industries:
Low Melting Point – With a glass transition temperature of about 220°F (105°C), ABS melts at relatively low temps compared to other engineering thermoplastics. This allows ABS to be readily injection molded.
Strength – Parts molded from ABS plastic exhibit high tensile strength and impact resistance. ABS also has good fatigue strength compared to other thermoplastics.
Durability – The material stands up exceptionally well to chemical exposure and physical wear and tear.
Machinability – ABS stock shapes easily on manual or CNC machining equipment, lending well to secondary fabrication.
Cost – Sourcing ABS plastic pellets for injection molding is relatively affordable compared to other engineering-grade thermoplastic resins.
Thanks to these properties and advantages, ABS injection molding is widely used across industries such as:
- Consumer appliances
- Automotive interiors
- Business machine housings
- Electrics/Electronics
- Construction applications
Essentially, ABS injection molding allows durable and complex plastic parts to be mass-produced at scale for all sorts of products.
How To Injection Mold ABS Plastic Parts
The ABS injection molding process itself resembles standard injection molding. Raw ABS plastic pellets are gravity fed from a hopper into the injection molding machine’s heated barrel.
A reciprocating screw feeds the pellets forward in the barrel and shears/melts the material. Once sufficiently molten, the material accumulates in front of the screw. The rotating screw then acts as a plunger – injecting the molten ABS through the nozzle, runners, gates, and into the awaiting mold cavity itself.
Here the ABS plastic cools and solidifies into the shape of the mold. After adequate cooling time, the mold opens and robotically ejects the molded ABS plastic part.
The precision tolerance capabilities, automated manufacturing means, and fundamental injection molding principles enable high volumes of dimensionally accurate ABS parts to be created via this crucial industrial process. And as we’ll explore next, proper ABS injection molding parameters help ensure high quality results.
Dialing In ABS Injection Mold Parameters
To create robust ABS injection molded components, plastic product designers and molding technicians carefully select parameter such as:
Melt & Mold Temperatures – ABS processing temps typically range from 400°F-460°F (204°C-238°C), with the high side maximizing part strength and low side improving precision. Meanwhile, mold temperatures of 140-212°F (60°C-100°) provide sufficient cooling.
Injection Pressures – Higher viscosity means increased injection pressure – generally over 10,000 psi – helps fill ABS mold intricacies. Though lower pressures suffice for basic geometries.
Packing Pressures – Packing pressure is applied once the cavity fills, compensating for material shrinkage. 400-1000 psi packing works for ABS.
Injection Speeds – Faster speeds minimize the chances of material degradation but slower speeds are necessary for thin walls. 15-80 mm/s covers most ABS injection molding applications.
Through careful configuration of parameters like these, manufacturers exact fine control over factors like molded ABS part density, internal stresses, precision, strength, and appearance.
The Many ABS Injection Molding Applications
Thanks to its versatility and manufacturability, ABS injection molding creates all sorts of plastic products across industries:
Automotive – Dashboard and interior trim components, cup holders, bumpers, wheel covers.
Consumer Appliances – Refrigerator liners, microwave components, vacuum cleaner bodies, monitor/TV covers
Business Machines– Printer and copier housings, monitor shells, keyboard bases
Medical Industry – MRI and CT scanning machine components, dental tools like denture bases and mouthguards
HVAC – Controls, interior fan shrouds
Plumping – Kitchen sink systems
And many more. Essentially any application calling for a rigid plastic material that must withstand rugged use and environmental exposure can benefit from ABS injection molding.
