ABS

ABS is an alloy made from three polymers, and its name is derived from them.

A – acrylonitrile (acrylic)
B – butadiene (rubber)
S – styrene

Like most alloys, ABS offers a balance of properties, with good strength, good stiffness, and good toughness. The material properties (as well as the raw material cost) will vary depending on the grade – which is usually determined by the ratios of the three polymers. Numerous grades are available, including grades specially formulated for super high impact, with excellent low temperature toughness. ABS is by default a very high gloss material, thanks to the styrene component. This makes it an excellent choice for consumer applications, and it is frequently used in housings for consumer appliances, consumer electronics, and general purpose power tools.

ABS is one of the older engineering plastics, having been commercialized by Marbon Chemical, a division of Borg Warner, in the 1950’s under the tradename Cycolac. One of the first commercial applications was for the housings of household telephones made by Bell telephone. (You remember those big old black housings?) The specific grade used in those phones was given the name Cycolac T (with the letter “T” for telephone).

classic dial telephone
image courtesy of freestockphotography.com

Borg Warner manufactured Cycolac until GE Plastics bought the ABS business from Borg Warner back in the late 1980’s. SABIC Innovative Plastics then bought the GE Plastics business in 2007, and renamed it. So all the former GE materials (Xenoy®, Lexan®, Noryl®, Cycolac®, etc), are now made by SABIC. SABIC is an international conglomerate, and is one of the world’s largest suppliers of thermoplastic materials.

ABS is an amorphous thermoplastic, which means it will have relatively low mold shrinkage, but it also means that is less resistant to chemical attack than a semi-crystalline thermoplastic. (This is not always a bad thing. The chemistry of ABS means it can be easily painted or even chrome plated.)

In summary, ABS is a workhorse material, and should be considered a staple in the portfolio of any design engineer.

copyright © 2011 by Eric R. Larson (a.k.a plasticsguy), all rights reserved.