Lately it seems like everyone I come across that uses plastics in their business is talking about the ‘performance of plastics’ and how plastics compare to each other. But, what are high performance plastics and what are the basic criteria for material selection? Do you really need high performance plastics in your application? The criteria for selecting plastic materials typically comes down to a combination of performance variables that best meet the needs of your application, or how the material will be used. Once those needs are met there is most likely a range of materials to choose from and often the least expensive material can be the starting point for writing a specification.
What Are High Performance Plastics?
In looking at our trusty Plastics Triangle we can see the top two tiers are called out as High Performance Materials
From the triangle we can also see these plastics all work under very high temperatures. If we look at factors such as wear resistance or the ability to take a lot of pressure, the crystalline side offers the absolute toughest materials for a job. At the very top the toughest materials of all don’t fall under either Amorphous or Crystalline categories, but rather a category all their own.
Why not Just Choose the Highest Performance?
If you purchase plastic materials you already know the answer to that question – PRICE! It can be very true that you get what you pay for and higher performance can mean more costly material. However, this is a careful balancing act, because a material that costs a bit more up front can be more economical in the long run. Buying a material that is right for a particular job can mean replacing parts less often, less maintenance, less downtime and more up time, and that improved efficiency can mean dollars in your pocket.
Why Are High Performance Materials Being Chosen More Often?
Manufacturing and industrial applications are increasing speeds, loads are increasing, and we are working in more extreme environments. Therefore the demands on materials increase too. Materials that operate at relatively slow speeds (less than 50 feet / minute) with light loads (less than 5 psi) may work well with UHMW or Nylon. But when the demands increase, we need to look to materials like Vespel SP-21 which can handle 350,000 PV unlubricated!
You may have also heard of ULTEM®, Radel®, Torlon®, or Techtron® PPS which are also capable materials that fit into the high performance category.
How do you Select a High Performance Material?
Let’s start first by asking a question –
“Is your application a
bearing and / or wear application?”
The group of materials that perform best in bearing and wear applications are found in the Crystalline Family of Engineering Plastics. When looking at these materials you will likely want to know two things:
1) What is the continuous running temperature of the application
2) What is the PV (pressure or force x velocity).
Knowing these two things can go a long way in figuring our which plastic material will give you all the performance you need for the best possible value.
I encourage you to find a good partner to work with you as you compare and contrast the different materials out there so that you can find the best material for your application. That is ultimately the best way to find the best performance / value for your money.
Sales and Marketing Manager
ThyssenKrupp Materials NA
AIN Plastics Division