TriStar has partnered with contact lens manufacturers on a range of projects, delivering precision solutions tailored to demanding production environments. Recently, a customer approached TriStar seeking assistance in developing a linear slide bearing for lathe slide tables used in lens production. The goal: minimize micro vibrations for precise machining.
From Rigidity to Flexibility: How Contact Lenses are Made
Contact lenses vary in form and manufacturing processes. Today’s lenses can run from lathe cut rigid plastics to injection molded discs, and even fully molded precision contacts. Hard gas permeable lenses are made using this technique. Hydrogels, including modern silicone versions, rehydrate in the eye.
TriStar’s engineers have provided precision bearings for both injection molding machines and high-precision lathes used to machine contacts from molded discs. Today’s application is for the latter.
Tackling Micro Vibrations at 6000 RPM
A customer designing a 6000 RPM lathe needed a linear bearing for X-Y slide tables. They considered ball slide units but found that, even when lubricated, the metal-on-metal conditions at that speed caused micro vibrations up to the tool holder. They needed something that would not only slide uniformly but also dampen any vibration from the tool.
Rulon J Delivers Unmatched Stability for Precision Applications
After evaluating the requirements, our engineers chose Rulon J. This grade has the lowest coefficient of friction of any Rulon material and bonds easily. It can then be secondarily machined to very tight tolerances. Other benefits include:
- Self-lubricating with a unique filler that adds temperature stability for enhanced wear
- Eliminates stick/slip
- Operates exceptionally well against soft mating surfaces such as 316 stainless steel, aluminum, mild steel, brass and other plastics
- Has a PV rating of 7500 ─ one of the lowest of all PTFE-reinforced materials
Since the Rulon J has consistent friction values from static to dynamic conditions, it enabled the finite movements required to cut these very thin (less than 0.1 mm) lenses with precise geometry. It's a fascinating process, and for those of us that wear contacts, it gives you a better appreciation for the technology behind this very common consumer product.
As the exclusive North American distributor, TriStar offers Rulon in diverse formulations for a wide variety of applications. If you need ultra-low friction and long wear life, or something that can withstand high loads in abrasive environments, Rulon is worth a look. We encourage you to reach out to explore the possibilities.
How Do Self-Lubricating Bearings Lubricate?
