Comparison between ABS and PP

As an engineer or product designer, you already know that you can choose from hundreds of commercial-grade thermoplastics that are suitable for both prototype and production parts. Yet within that giant universe of plastics, we often see designers and engineers we work with turn to materials that are preferred or more commonly used than others.

Two examples are ABS (acrylonitrile butadiene styrene), which is a combination of several different molecules, and polypropylene (PP), which is a chain of a single type of molecule. Why are these plastics used so frequently?

ABS is one of the most affordable thermoplastics and has excellent mechanical properties such as durability and rigidity, and has a high heat-deflection capability. Easy and fast to machine and fabricate, ABS has excellent “machinability.”

PP is also an affordable thermoplastic, in fact it is generally less expensive than ABS. It is durable, tough, flexible, low in weight compared to other plastics, and is resistant to moisture absorption. The density of PP is less than 1 g/ml, so it floats on water. PP’s properties are similar to polyethylene, but the material is slightly harder and more heat resistant, in fact it has better heat resistance than ABS.

Both ABS and PP work well with CNC machining, injection molding, and industrial-grade 3D printing (additive manufacturing). Here’s a look at the benefits and applications of these two workhorse materials, and, at the bottom, a table that compares typical material properties of these two plastics among the three manufacturing methods of machining, molding, and 3D printing (specifically, stereolithography).

For the ordinary ABS plastic and PP plastic, they both belong to olefine copolymer. Meanwhile, ABS has better comprehensive properties than PP plastic, which can be verified easily by checking the prices of ABS plastic and PP plastic. The price of ABS plastic per ton is much higher than that of the PP per ton.

ABS, acrylonitrile butadiene styrene, is a common thermoplastic polymer. Some properties of ABS are the same as the PP's. At the same time, ABS also has some other properties that PP does not have.

ABS is impact resistant, which means it has better toughness than PP. The temperature resistance of ABS is also better than PP's. Both ABS and PP have shiny surfaces, and the surface of ABS is shinier than PP's.

All in all, ABS has better properties than PP and can be used to produce all the products made of PP in general.

ABS is nontoxic and more used for structure materials while it is rarely used for the package and the commodity such as the utensil.

ABS has various advantages. But it is not resistant to the high temperature, which is the common property of the plastics. However, the highest service temperature of the ABS products plastic can still meet the requirement of the electric appliance shell's.

PP, polypropylene, has wide applications too. In engineering applications, for example, polypropylene is also used for the automobile bumper. In the textile industry, the thread made of polypropylene is called the polypropylene fiber, which is usually used for textiles, ropes, fishing nets, etc.

Polypropylene is nontoxic. The processing technology and the applications of polypropylene are similar to those of PE (polyethylene). Polypropylene can be toxic due to its processing aids and performance additives.

It should be noticed that polypropylene has poor weathering resistance and the inhibitor containing heavy metal might be used in the manufacture of the polypropylene products.

Compared with the PE product, the PP product has better heat resistan