Tech Talk Blog

Our team is designing a lens that must withstand military extremes such as salt spray, fog, humidity and temperature.  The coating must be abrasion-resistant and anti-reflective – what is the best treatment?

This is a great question — and a multi-step process. Assuming your lens is a polymer lens like polycarbonate or CR-39, currently there is no single surface treatment for both anti-abrasion and anti-reflective (AR) properties.  Instead, one would apply the anti-abrasion coating first, followed by the AR process, which is done in a vacuum for a uniform and consistent result.

Your abrasion-resistant coating options include:

A)    Polyurethane  – This usually is the most economical coating, which is applied by either sprayed or dip method. This is a popular treatment for end user ophthalmics, but also has the least durability and longevity.

B)    DLC (Diamond-like coating) – An extremely hard, durable coating, that is relatively expensive, but most effective for high-end users.  DLC ensures high-performance and impact-resistance as the resulting surface is very close to the hardness of diamond.

Our team can help you explore your best solution.

What is the best process for removing silicone oil from a catheter made of Pebax® tubing prior to a bonding operation?  Would you use plasma or corona?

Your question is one that we are seeing more frequently. And the short answer is that it all depends on the amount of oil.

If you can see a significant oil collection, then you need to wash the tubing in an ultrasonic bath with an emulsifier. Then, you may simply wipe the tubing with an alcohol wipe to remove any excess. It really depends on the level of contamination. Generally speaking, I’ve found that catheters have a superficial level of oil.

If the amount of oil is superficial, plasma can carry away the excess oil via a specific oxygen treatment. We do not advise corona treatment for this application, since it can make the silicone hydrophilic and give a false impression of being clean. Plasma is a more elegant solution and will “superclean” the surface to promote better adhesion.  Learn how we recently solved this challenge.