Q. Our machine shop is considering Rulon® parts for a new application. What are some key properties and which configurations are available?
A. Rulon is an incredibly versatile material and it is very easy to machine. Cutting, grinding, drilling, turning, and screw machining – call us for advice on any of these techniques.
In terms of surface properties all Rulon formulas have very good properties:
- Temperature range of -400 to +550°/600° F
- Inert to most chemistry
- Zero moisture absorption
- Self-lubricating design
- Variable thermal expansion properties
- Outstanding wear life and strength
Rulon materials are available in:
- Standard sleeve, flange and thrust sizes to match bronze standards
- Rod, sheet, tape or tube forms are available for in-house machining
This is just a quick overview, you can also consult our Rulon Bearing Selector Guide to learn more. Or just Ask the Experts for a consultation!
Did you know that Rulon® is a preferred bearing material for many food industry applications?
Several formulas comply with appropriate FDA-guidelines, resist boiling temperatures as well as the heat and humidity of ovens. Rulon parts are deployed in food applications ranging from oven carts, to industrial mixers, oil circulation pumps and even beverage canning equipment.
Here are just a few of the Rulon formulas that excel in food production:
- Food-grade bearing material
- High load-bearing properties for extreme food handling
- Resists caustic sanitation chemicals required of a food environment
- Food-grade bearing material
- Excels in submerged applications, even boiling temperatures
- White, stain-resistant color to promote sanitation
- Excellent unlubricated dry service at all temperatures
- Zero moisture absorption for use in high-humidity environments
- Low friction to promote smooth operation
Download our food industry white papers to read how Rulon excels in real-world canning, bakery, rotisserie ovens and other food applications.
With literally hundreds of Rulon® formulas, matching the right blend to your application specifications can seem overwhelming. Each unique filler can dramatically alter the property characteristics of Rulon materials. Of course, you can always contact our experts to guide you through the selection process. But we also wanted to note some of the key questions that will help you identify which formula is the ideal fit.
Here are seven questions you should ask to start the selection process:
- What is the function of my part?
- Is there a wide operational temperature range?
- Do I need FDA, USDA or other agency compliance?
- What are my typical speed requirements?
- What are the expected bearing loads?
- Is the mating hardware soft or hard?
- How about the surface finish?
Ready to take the next step? Just ask us, TriStar is the exclusive US supplier of Rulon materials.Ready to take the next step? Just ask us, TriStar is the exclusive US supplier of Rulon materials.
Our recent post about promoting the adhesion of Rulon® J through plasma surface modification sparked quite a few calls to our design team. So what is Rulon J and when does it make sense to consider altering its surface properties?
Rulon J is one of the most-common formulas, it is a self-lubricating material and contains a unique filler that adds superior temperature and wear properties. Rulon J is also the material-of-choice for soft mating applications. Shafts and bores made of aluminum, brass or stainless steel are unaffected by Rulon J. Common applications include bearings for pick-and-place devices, high-speed linear bearings, pneumatic sealing devices and extremely low-friction slide pads.
Rulon J is also a good candidate for plasma surface treatment to help improve lap shear bond strength. In fact, we’ve tested the material after plasma treatment, and have noted an improved bond strength of roughly 117%.
Want to learn more about the benefits of Surface Modification? Download our new white paper, How Low-Pressure Plasma Treatments Can Benefit your Manufacturing Process. You may also be interested in Rulon Engineered Materials ― Quality Assurance Begins with Precision Processing.
Q: We are designing plane bearings made of Rulon®, what are some key considerations in terms of coefficient of friction?
A: This is a question that we hear often regarding Rulon, Ultraflon and other PTFE-filled materials. The short answer is that these design materials are exceptions to the general rules of friction. With most materials, you can presume that higher loads and higher speeds would mean higher friction. But with PTFE-filled materials, the opposite is true; the higher the load and speed, the lower the friction. This is important to keep in mind when designing, since surface contact area can be reduced dramatically to optimize friction properties.
We’ve prepared a Coefficient of Friction video that covers this topic in much greater detail, but also invite you to reach out to Our Experts to review your application needs.
Report reveals how plasma surface treatments increase the performance of
polymers and other materials!
Download your free copy of Surface Modification: How Low-Pressure Plasma Treatments Can Benefit Your Manufacturing Process to learn how surface modification techniques are solving a broad range of manufacturing challenges. From bonding contrasting materials and increasing the strength of adhesives, to improving paint applications and creating permanent moisture, plasma surface modification improves the performance of manufacturing materials.
Our new paper answers common surface modification questions, including:
- Which surface modification method is the best fit for my application?
- What are the advantages and considerations of each process?
- Why should I consider plasma treatment?
- How does plasma cleaning compare to conventional surface cleaning?
- Which devices are benefitting from surface modification treatments?
You’ll also review real-world examples of surface modification at work in medical, diagnostic, textile, and other industries.
Get your free copy today! or reach out to our in-house Experts for a custom solution to your surface modification challenge.
Q: What are the adhesion differences between untreated Rulon J and plasma-treated Rulon J?
A: Our team recently conducted a short study to find out. Rulon is an engineered tetrafluoroethylene polymer mixed with other materials; polymeric or inorganic. Since Rulon is partly comprised of a fluorocarbon polymer, it is difficult to achieve good lap shear bond strength without surface treatment. Sodium naphthalene ammonia dips or liquid etching of fluorocarbons are effective to enhance the adhesion of fluorocarbonpolymers. However, these are highly caustic and can be dangerous and difficult to control, and we found that the resulting dipped surface discolors to brown or black.
Alternatively, plasma surface modification is as effective as this dip method, yet it is safe, controllable and repeatable ― all without discoloration. Plasma is a quasi-neutral cloud of ion, electrons, and radicals. The diffused cloud is capable chemistry on the surface of materials that is unique, providing wettable or adherent surfaces on materials that are otherwise inert. The Rulon J samples in this study were subjected to a specific plasma gas mixture to induce and adherent surface for a structural epoxy adhesive.
Below are the results:
In brief, it is difficult to achieve strong lap shear bond strengths with fluoropolymers.
Traditional surface preparation methods are dangerous and discolor the material. With plasma surface modification, the bond strength improves by approximately 117% without discoloration.
*It is important to note that the maximum pull strength of the treated sample was compromised by the deformation of the test specimen.
Learn more about the study from our in-house team, or download our Rulon white paper today!
In the last few weeks we’ve reviewed the importance of having a good bond adhesion in order to ensure proper device performance. But it is just as important to be able to recognize an adhesive bond failure. So what should you be looking for?
There are 3 primary types of bond failure: adhesive, cohesive, and substrate.
This is the most common failure when bonding dissimilar materials. The adhesive (glue, paint, coating, tape, etc.) has more chemical and/or mechanical attraction to one substrate than the other. When the bonded material is submitted to lap-shear testing (pulled apart by hand), the two pieces come apart and all (or most) of the adhesive remains on one substrate. This is referred to as “delamination.”
This is most common failure when the adhesive is too weak for the intended application. As shown below, the adhesion to the substrates is greater than the structural integrity of the adhesive. This can occur with “soft” adhesives like certain urethanes and silicones. It can also occur if the adhesive bond-line is applied too thick.
This is the best type of failure. It simply indicates that the strength of the adhesive bond and the adhesive itself (and the correct amount applied) is the right formula for the application.
We can help you avoid a surface bonding failure. Just Ask an Expert!
We are often asked about which method is best for preparing fluoropolymers for a bonding application. The most critical step is bonding is to ensure that you begin with a clean surface.
Fluoropolymers are a group of polymers in which all, or most, of the hydrogen has been replaced with fluorine. They have a wide range of mechanical, frictional, chemical, and electrical properties which make them ideal for a many different applications. However, these properties result in such low surface energy levels they are difficult to bond without surface pretreatment.
Sodium-etch solutions are one common surface treatment used for bonding, but they have significant disadvantages. The wet chemicals are expensive and dangerous, do not coat uniformly, and are very difficult to dispose of. A better method of preparing polymers for bonding is by plasma treatment.
The TriStar team has had good results with surface treatment of fluoropolymers such as FEP,PFA, Tefzel®, and PTFE (Teflon®) with gas plasma. If an appropriate process is used, the surface of the fluoropolymer is chemically modified and becomes water-wettable, printable and bondable with structural adhesives. The plasma treatment is uniform, dry (no wet chemistries), efficient, and safe. And the process is earth-friendly with no disposal issues.
Wondering if plasma is the right treatment for your bonding challenge? Reach out to our team to learn more.
A question was posed to our Ask the Experts line wondering about the differences between plasma surface modification and corona treatment. While there are a variety of surface modification techniques to help achieve desired results, today we’ll compare some of the key advantages and considerations of plasma treatment vs. corona.
Plasma can readily prime any surface for adhesion, painting, coating or printing applications. Plasma is a good option for components that require a longer treatment hold before moving to the next step in manufacturing. Other key advantages of plasma treatment include:
- Good surface chemistry selectivity
- Enhanced control of gas type, flow, pressure and concentration
- Three-dimensional treatment
- Earth-friendly process that uses no damaging solvents
- Price is relative to system size; as the system size increases the price increases
- Throughput is restricted by batch-to-batch logistics
- In-house systems can be very costly; it most cases outsourcing is a better value
Corona is a form of plasma at standard atmospheric pressure and is normally used with in-line processes such as plastic film, which is where treatment shines. Key advantages include:
- Price of purchasing a system for in-house treatment
- Systems are robust and easy to maintain
- Lack of surface chemistry selectivity
- Limited polymer choice
- reatment is two-dimensional
See our video for additional information on the strengths and advantages of Surface Modification.