With a combined seven decades of machining parts out of plastic for every application imaginable, the team here at Paradigm Polymer knows a thing or two about types of plastic. We thought it might make sense to share some of that knowledge with those seeking to understand the properties of various polymers and the applications for which they are best suited.
Let's start with the big three (or, in this case, four, as our customers call for just about as much Ultem as they do PCTFE).
Polytetrafluoroethylene (PTFE)
Polytetrafluoroethylene is the plastic we use the most here at Paradigm Polymer. It has extremely low friction, provides excellent chemical resistance and high-temperature resistance, and is known for its non-stick properties. Its dielectric properties make it the most common choice for insulators in electrical assemblies. Our customers specify it primarily for seals, gaskets, bearings, and insulators.
Polyoxymethylene (POM) - commonly referred to as Acetal
Acetal is a high-performance engineering thermoplastic used in a wide range of applications due to its high stiffness, low friction, excellent dimensional stability, and superior resistance. Typical applications for Acetal include gears, bearings, bushings, and fasteners.
Polyetherimide (PEI) - commonly known as Ultem
Ultem is another high-performance thermoplastic known for displaying excellent mechanical and dielectric properties, high
thermal stability, and flame resistance. Some of the more typical applications we see with Ultem are electrical insulators and connectors, diagnostic casings, valve seats and seals, and wear-resistant bushings and bearings.
Polychlorotrifluoroethylene (PCTFE)
PCTFE is a thermoplastic polymer with a unique range of properties that make it suitable for some specialized applications: high tensile strength, thermal stability over a wide temperature range, dimensional stability, and chemical non-reactivity with excellent vapor and moisture barriers. It is an excellent plastic for aerospace seals and gaskets, chemical processing environments, cryogenic valve and seal componentry, and applications requiring chemical resistance and biocompatibility.
Polyetheretherketone (PEEK)
PEEK is a high-performance engineering thermoplastic known for having excellent mechanical and chemical application properties. It possesses high mechanical strength, is resistant to a variety of chemicals, including acids, bases, and organic solvents, exhibits good wear resistance and low moisture absorption, and is highly biocompatible. It is a first choice for medical components, aerospace, and automotive industries (bearings, seals, gears, and insulators)as well as industrial and electrical applications.
Nylon (Polyamides)
Nylon is a generic designation for a family of synthetic polymers known as polyamides; common traits exhibited by nylon include high tensile strength, excellent chemical and wear resistance, moderate to high temperature resistance and friction resistance. It is commonly used for bearings, bushings, fasteners, gears, and washers across a variety of industries and as an insulator for connections in electrical and electronics applications. It is especially suitable for machining parts requiring tight tolerances and intricate geometries.
Vespel® (Virgin Polyimide)
The exceptional thermal stability, chemical and wear resistance and low friction exhibited by Dupont Vespel make it a premier polymer for manufacturing high-performance plastic parts. It is also known for low outgassing and having excellent dielectric properties. Specific applications include bearings, bushings, insulators and seals for aerospace, automotive and semiconductor components, and its ability to withstand sterilization processes and high level of biocompatibility make it useful for medical and surgical devices.
Acrylonitrile Butadiene Styrene (ABS)
A defining characteristic of ABS is its high resistance to impact and its rigidity, which provides a good balance between strength and flexibility. It also exhibits a surface finish with good adherence qualities, so it can be readily painted or plated. ABS is widely used in the automotive and consumer electronics industries for dashboards, trim, and electronics housing. A well-known use of ABS is in the durable toy space, with LEGO bricks as a prime example.
There are a host of other plastics that can be used to manufacture parts, but these are the primary ones utilized in our shop. When selecting a plastic to be used for a part, the following are the key considerations we generally discuss with our customers:
Application Requirements: Consider the mechanical, thermal, chemical, and electrical properties required for the specific application.
Processing Techniques: Determine the most suitable processing method for the polymer, taking into account the complexity and volume of parts.
Cost: Balance the performance benefits with the material and processing costs to ensure economic viability.
Environmental Factors: Evaluate the polymer's resistance to environmental conditions such as UV exposure, moisture, and chemical exposure.
Design Constraints: Ensure the polymer can be machined to the desired specifications, with considerations for dimensional stability and surface finish.
If you would like to discuss developing a part with us, please contact us via email or on 1 (860) 526-3565.
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