Friction, wear and lubrication of plastics

Tribology is the science and technology of two surfaces in contact and relative sliding. Polymers behave quite differently than metals when it comes to tribology. The coefficient of friction was established as a constant by Amontons in 1699 but this is mainly true for metals in dry sliding. Polymer sliding is dominated by adhesional interactions thereby rendering the coefficient of friction a non-constant. Several do’s and don’ts in polymer tribology will be revealed and a scientific/technological solution for very low polymer friction will be served. Without lubrication, of course.

Sometimes neat resins may not provide the performance needed in term of strength, fatigue or wear. SABIC’s Specialties’ LNP™ compounds portfolio is based on a variety of reinforced and internally lubricated thermoplastic compounds to address such needs. In this contribution, we will present internally lubricated solutions with an emphasized on our fully compatibilized olefinic alloys which can serve as an alternative to PTFE based material and show that these can emulate the tribological performance and colorability of traditional lubricated materials while avoiding the use of PTFE.

Trelleborg’s Lubrication Management technology approaches hydraulic sealing and lubrication systems from a comprehensive perspective, in which each element is a complementary component of a unified whole. Lubrication Management technology uses adequate lubrication to reduce the load on each sealing element, thereby optimizing the performance of the hydraulic system in terms of friction, wear and lifetime.

Surface deviations are the small-scale geometrical deviations that always occur during manufacturing. Since surface deviations significantly impact the functionality, reliability, and performance of engineered products and systems, these deviations must be controlled. Surface texture is the term in ISO GPS (Geometrical Product Specifications) used to specify and verify allowed surface deviations on drawings, using parameters with tolerances and the correct measurement method. This presentation provides an introduction to ISO GPS and the toolbox for surface texture

The presentation will provide a brief overview of the influence of fillers and their respective orientation on wear and friction testing. Processing methods of articles, or samples do have an influence that will be exposed. Last but not least, mating materials and their surface have an influence on wear and friction testing that should be observed.
The presenter will also show that there have been wear and friction compounds without PTFE around since long ago and explain why they are not widely known.

From the first LEGO bricks were produced until this day, where millions and millions of bricks exist, only one thing has been holding them together. And that is friction. Because of the importance of friction the LEGO Group has studied this property of plastics for many years.
This presentation will focus on the current methods used for quantifying friction used by the LEGO Group and the background for why the methods are designed, as they are. Some of the challenges of measuring friction properties on plastics will be discussed and some applications of friction data will be introduced.

Many tribological coatings are made of PTFE (Teflon) due to the very low friction of this material. PTFE is a PFAS that are very soon to be banned due to their negative impact on the environment.
In this presentation, an example is given where polyethylene is used as a substitute for PTFE. It has the same friction properties as PTFE and can match the physical properties except in high temperature applications. It is shown how the polyethylene is applied to a steel surface and how the coating performs in a very harsh friction test.