Supply Plus Ltd designs, manufactures, supplies and distributes safety and fuel delivery equipment, with brands including AS Fire & Safety, Bayley and Collins Youldon. The application Our customer, Supply Plus approached us with a requirement for their 2” Swing joint power spindle. The outlet pipe from the fuel tank on delivery vehicles is fed into … Continued
An existing customer (an automotive manufacturer) approached our engineers with an application where they were experiencing failures of a seal designed and manufactured by another rubber seal provider. The application This moulded gasket is used within a valve housing in an automotive application. The competitor gasket experienced failure at the “T-junction” areas of the seal. Our customer … Continued
Our customer manufactures high performance oil and vacuum pump solutions, and approached our engineers with a new O-ring application for review. The application Our customer required an FKM (Viton™) 60 shore special O-ring. This is to meet Porsche material specification PN707 Class 2 (Oil), Class 5 (Fuel/FAME mix) and Class 12 (Blowby gas). This proved … Continued
The electric vehicle industry is growing; global manufacturing and registrations of electric vehicles is increasing exponentially each year. Our engineers have extensive experience in designing seals for automotive applications, but we still find new challenges involved in sealing components within hybrid, hydrogen fuel and full battery powered electric vehicles. The Application Our customer has 30 … Continued
Polytetrafluoroethylene (PTFE) is a thermoplastic polymer that can be used in a variety of sealing applications; it is particularly suitable where the application conditions exceed the parameters of elastomeric seal use, but are not as highly demanding as applications that require the use of metal seals. What is PTFE? Discovered accidentally in the DuPont™ laboratory … Continued
The use of metal seals as an engineered sealing solution is appropriate where it is not possible to use elastomeric or polymer seals due to extremely demanding application requirements. For example, these could include applications with extremely high temperatures (300°C upwards) and pressures, intense radiation, cryogenic conditions or highly aggressive chemicals. How do metal seals … Continued
Where a seal groove follows an irregular path or profile, a common sealing solution is to design a custom Push-In-Place (PIP) gasket that has the same profile as the centre line of the groove, simply drops into place and is retained by the features of its own design. Gasket sealing overview There are many ways to seal the … Continued
Propelled by one or more electric motors and using energy stored in rechargeable batteries, electric vehicles are quieter, have zero exhaust emissions and lower emissions in general compared to internal combustion engines. The number of electric vehicles on the road grows exponentially every year globally, and our engineers support manufacturers with innovative sealing solutions in these specialist … Continued
3D printing has developed significantly and now performs a crucial role in many applications. 3D printed products vary from fully functional to purely aesthetic applications; with the most common application being for manufacturing. Here we discuss how our engineers use 3D printing to demonstrate a seal concept. What is 3D printing? 3D printing is typically … Continued
All seals require some form of installation into application hardware and often this may seem to be a simple push in place function. However, without consideration of certain conditions this can potentially create sealing problems further into the life cycle of the seal. Once installation is achieved a seal can often sit in the housing … Continued
All seals require some form of installation into application hardware and often this may seem to be a simple push in place function. However, without consideration of certain conditions this can potentially create sealing problems further into the life cycle of the seal.
Once installation is achieved a seal can often sit in the housing hardware for many months – which potentially allows it to stick to the housing material and cause further issues. This is where O-rings with special coatings can make a difference.
The main function of coatings is to improve installation into the hardware and to lower friction within an application; but there are many other benefits too. They often mean that lower assembly forces are required and by not using grease lubricants seal parts don’t stick together in packaging for transit. Special coatings for O-rings can be manufactured in different colours. This is so seals and O-rings for specific applications can be easily identified. This is without the need to reformulate the elastomer compound with colour additives.
All of these reasons make them easier to handle for users during installation.
There are a variety of coatings and lubricants available for the surface area of seals. They’re mainly divided into two common categories; wet coating/lubrication or dry micro film coating. Historically, coating technology was limited to just using wet type coatings. For example these may include silicone oils and greases and mineral oil based greases. The coating process would involve simply dipping the seals in the oil or grease during manufacture, or during installation on site. This is often a messy process, and although a relatively low-cost method, wet coating is less common. This is because more applications demand higher levels of cleanliness and control of products. Low contamination has become a key factor.
Alongside the typical wet coatings traditionally used, there is an extensive range of what is often referred to as dry coatings. Common offerings are silicone dry coating, PTFE coating, PFPE coating, special polymer coating and MoS2 dry powder coating. These are applied during the manufacturing process and bagged in a clean and efficient process, delivered and ready to be installed into application straight from the bag.
Dry coatings are fast becoming the coating of choice for many customers, with PTFE dry coating being one of the most popular. Commonly applied to O-rings, the process involves the PTFE polymer being spray applied to the O-ring elastomer surface area. Therefore creating a microscopic thin film layer. At molecular level the PTFE then creates a covalent like bond to the surface ensure a high quality finish.
The low friction properties of PTFE gives the advantage of low assembly forces. For example an O-ring assembled to a piston can be installed easier into the bore hardware housing mating part. Consequently, this significantly reduces the chance of installation damage (like pinching of the O-ring elastomer material). PTFE coatings can also be used as a short term dynamic improvement to a sealing solution, as many seals suffer from the phenomenon called stick slip. This can occur where a seal has remained in the application hardware bore for a medium to long period of time. It then starts to adhere between the surface of the elastomer and the mating metal material, causing sticking. When a PTFE coating is applied between the elastomer and the metal hardware it creates a low friction barrier. This provides a significant advantage over uncoated parts. This is because the PTFE coating generates a low friction layer. This greatly reduces breakout friction and resolves the stick slip issue therefore greatly improving the performance of the application.
Because the PTFE is a thin polymer layer, coatings can be manufactured in a range of colours by adding pigment to the recipe. Typical colours include, green, blue, red, yellow and orange. By adding these colours the customer benefits from easy identification and production line inspection. Furthermore allowing seals to be easily identified even once installed.
Find out more about our range of O-rings with special coatings and the different materials O-rings are available in HERE