What is hardware surface finish? Any surface can look (and even feel) perfectly smooth. However, look closely enough with high magnification and all surfaces will have a degree of fluctuation. The topography will look similar to a mountain range or the surface of the moon! The way a surface is produced or machined, along with … Continued
Using Finite Element Analysis (FEA) in seal design Finite Element Analysis (FEA) is a computerised modelling method for predicting how an object reacts to forces, whether directly applied or generated by pressure, temperature effects or vibration. FEA provides data to help predict how a product will function under those applied conditions. Additionally, it identifies areas where … Continued
Are all elastomers the same? Material hardness This is often the least considered property when selecting a material. In sealing applications, elastomer material hardness can impact assembly loads, seal friction and extrusion resistance. Softer rubber can better accommodate surface imperfections (especially when sealing low pressure gas). This means softer seal compounds can be used effectively … Continued
The importance of engineering tolerances What tolerances are we concerned with? We can start with the seal itself, and specifically the seal material, as almost all polymer seal materials contain multiple ingredients. For PTFE and polyurethanes this is typically 2 or 3 different elements. However, for an elastomer material as many as 30 different ingredients … Continued
Elastomer manufacturing moulding processes Compression moulding This is the simplest method of converting a piece of rubber into a finished seal product. The rubber compound is first mixed and prepared, and depending on the recipe can require up to 30 different individual ingredients. At this stage the curing (or vulcanization) of the rubber hasn’t yet taken … Continued
Polyurethane as a seal material The foam in your armchair. The strap on your wristwatch. The wheels on a supermarket shopping trolley and beyond; Polyurethane certainly has a diverse range of uses since its invention almost 85 years ago. Aside from day-to-day products; it is also a highly capable and versatile sealing material – and … Continued
Why the focus on PFAS? PFAS is a blanket term used to describe Poly- and Per- fluoroalkyl substances. There are currently around 10,000 substances in existence that fit this description, with potentially more variants still yet to be produced. Some are already known to be harmful to human and animal health and the environment (such … Continued
Seals for cryogenic applications Cryogenic sealing means controlling or sealing a media at very low temperatures. This process can be complex and advanced, and spans a range of markets; from pharmaceutical, chemical and refrigeration, to automotive and electronics. What are low temperatures for seals? A typical industrial sealing system will operate in the realms of a … Continued
Why use 2-shot moulding? 2-Shot moulding is a manufacturing process that allows the co-polymerisation of hard (or soft) plastics and thermoplastic elastomers (TPE’s). We use the 2-Shot manufacturing approach to deliver engineered parts that perform a critical sealing function. What is 2-shot moulding? A 2-Shot mould is designed with a top and bottom cavity. During … Continued
Why use PTFE seals? Polytetrafluoroethylene (PTFE) is a thermoplastic polymer. PTFE seals can be used in a variety of sealing applications. It’s suitable when application conditions exceed parameters of elastomeric seal use but not to the extent of a metal seal. What is PTFE? It has a high melting point (342 °C) and morphological characteristics. … Continued
Polytetrafluoroethylene (PTFE) is a thermoplastic polymer. PTFE seals can be used in a variety of sealing applications. It’s suitable when application conditions exceed parameters of elastomeric seal use but not to the extent of a metal seal.
It has a high melting point (342 °C) and morphological characteristics. These allow seal components made from virgin PTFE to be used continuously at service temperatures of up to 260 °C. With the addition of fillers – up to 300°C. It has the unique ability to resist material degradation, heat-aging and alteration in its physical properties during temperature cycling. Alongside this rare combination of material characteristics, PTFE also has unlimited shelf life.
Notably PTFE demonstrates extraordinary chemical resistance. The intrapolymer chain bond strengths preclude reactions with most chemicals, thereby making it chemically inert at elevated temperatures and pressures with virtually all industrial chemicals and solvents. Only a few media (some molten alkalis) are known to react with PTFE seals making them the perfect sealing solution for highly aggressive chemical applications.
PTFE also has the lowest friction coefficient of any known solid. It has self-lubricating capabilities which offers continuous dry running ability in dynamic sealing applications and has superb stick/slip capabilities.
The advantages of using PTFE in sealing applications are multiple:
Our range of PTFE seal products include back-up rings, rod and piston seals, slipper seals and spring energised seals in a wide variety of sizes. Materials depend on application requirements. However, we offer a wide range from Virgin PTFE or including filler combinations of MoS2, glass, carbon, carbon fibre, graphite, and bronze.
These characteristics make PTFE seals perfect for the demanding applications involved in Oil & Gas, Aerospace, Automotive and Chemical Process markets (to name but a few). Ceetak’s engineering team are experienced in the design of PTFE sealing solutions to meet the complex specifications these types of application demand.
Read our overview and more detail about PTFE seals HERE