WHAT YOU NEED TO KNOW ABOUT... CO2 and Plasma Technologies

By Christie Walker

Over the last 70 years, the course of major technical developments in the optical laboratory business has not always been one of unique innovation. Often it is the case that “new” optical technology is adapted for use in optics after development in other industries.  

Practical AR coatings were invented in the 1930’s for military use, but only became common place in eyewear many decades later.  What we call free form manufacturing, which started in the late 1940s, did not enter the optical field until the mid-1990s. This is true for the introduction of the first plastic lenses, the substrate being first developed for use in airplane canopies. Memory metals in frames, photochromic, polarized, and other materials were also developed in other industries and adapted for use in eyewear.

With this in mind, where does a future-leaning lab owner look to stay in front of the competition and take best advantage of advances in technology that will increase yields, improve quality and turn-around time while supplying the best product?  What new “outsider” technology could we see soon in ophthalmic optics

Already well established in other industries, be prepared to see advances in “dry” lens milling, using directed CO2 (and other inert gas) jets in place of water and coolant to functionally lubricate and remove heat during surfacing.  In use today in other medical device production, single point cutting of plastics is taking place using cold dense composite CO2 gas streams that replace and in many ways are superior to wet milling. The features include no water, no oils or cutting lubricants per se, with the substrate remaining dry, clean and cool through the milling process.

With over a decade of serious application in aerospace, computer hard drive, and solar industries is the use of atmospheric plasma for substrate cleaning and coating/bonding adhesion improvement. When plasma is combined with inert gas vectoring sprays (such as CO2), the jets of clean dry gas remove the debris caused by the plasma etch and the fractionation of surface contaminates,
as well as heat contamination. This hybrid technology has proven transformative for the hard drive industry, as disk drive platter surfaces can be cleaned in this manner both water and solvent free for fractions of a penny. Organic ophthalmic substrates treated with this process show increased wettability and demonstrate excellent coating adhesion while retaining the benefits of lower cost of production, and short processing times.

With many years of established service in aerospace, automotive and electronics applications, and with the technology already making small in-roads in a number of large scale optical operations for lens blank production, be ready to see this technology at the lab level soon.  As this unique process can replace traditional “wet bench” DI water, ultrasonic and caustic cleaning, labs can see savings in time and cost in both hard coating and pre-AR production with application of this CO2 technology. Small scalable units will prove very efficient when introduced into standard ophthalmic lens production, reducing footprint, energy consumption, and water usage in optical laboratories.  

For more information or to carry on the conversation, contact BSP at [email protected]


Labtalk June 2020