LabTech May/June 2015

By Staff

STEVE SCHNEIDER
Director of aftermarket products and sales, Satisloh

HOW CONSUMABLES IMPACT PROCESSING
A continual objective for most labs is lowering their overall cost per surface. And they typically begin with examining consumable expenses— often seeking third party suppliers for cheaper materials such as diamond tooling and lens polish. Initially this may positively impact their bottom line; however in the long term it negatively affects both lens quality and equipment performance. While a third party vendor may offer a “like” product, it has not been thoroughly tested and validated by the process designer. The result is greater lens spoilage and/or machine issues—contributing to lower productivity and increased costs. Introducing unknown variables to the process hampers troubleshooting efforts when issues do arise.

While polish chemistry has always been important to surfacing, it’s even more critical for digital surfacing. Using a polish engineered in conjunction with the appropriate polish caps provides the best quality.

Satisloh offers multiple digital polishing processes specifically designed for Satisloh equipment. Labs can choose the Satisloh process that best fits their production needs.

The best solution is to work with your machine supplier for the most economical process available that meets your lab’s specific needs. Most of them are working hard to develop new tools and techniques that provide greater flexibility and enhance your profitability. By taking this direction you are assured that your complete process has been developed and tested to work seamlessly with your machines. Steve Schneider, director of aftermarket products and sales, Satisloh

 

CRIS DEREJOAS
Lens coatings application engineer, Coburn Technologies

LET’S TALK PREVENTATIVE MAINTENANCE
Preventative maintenance is extremely important, especially when it comes to spin coaters. The most common defect during the coating process is referred to as a “pit”. This can occur when any type of foreign particle is on the lens surface prior to being coated.

Replacing consumable parts exactly as the manufacturer recommends is key to consistently maintaining high coating yields. Most equipment manufacturers’ maintenance requirements are based on eight hour days, five days a week. If a lab is working two or three shifts per day, the maintenance schedule must be adjusted accordingly.

For example, most spin coater manufacturers recommend replacing the wash tip and screen every eight weeks based on a forty hour work week. If a lab runs three shifts, then the wash tip and screen should be replaced every two weeks.

It is critical to replace consumable parts such as the wash tip and screen for many reasons. The obvious job of the wash tip and screen is to be the last line of defense to assure the lens is clear of debris before being coated. However, it is important to remember that water is a solvent. Most labs use DI water which is the most corrosive type of water. The combination of the natural solvent properties and the high pressure from the water pump will rapidly break down the steel wash tip and screen. As a result, microscopic particles of steel will end up on the lens, causing pits. Instead of acting as the last line of defense, the tip and screen have become the direct cause of the defect it was designed to prevent. Cris DeRojas, lens coatings application engineer, Coburn Technologies

 

NICOLAS KANE
Consumables product manager, North America, Schneider Optical Machines Inc.

DIGITAL POLISHING TOOLS, JUST A COMMODITY?
Absolutely not! Among the most fascinating aspects of digital surfacing is the science behind the process parameters. Working under strict guidelines, companies spend thousands of R & D hours yearly to create the latest, greatest and fastest ways of processing digital lenses. Just remember, it takes only 13 hours to build a Toyota, and 6 months to build a Rolls-Royce. 

Digital polishing processes are always developed around a specific machine and consumable parameters! For example, if an aftermarket tool is too thick or rigid, it may last longer, but at the expense of design replication and surface yields. The process was designed for the polishing tools to conform to the greatest range of curvatures and lens types. During R & D, the OEM balances tool life, cycle time, and material mix for the best intended results. Polishing tools have been developed in direct conjunction with the overall process. Don’t waste the brilliance of what has been created by changing the variables that have yielded success in the past.

Machinery Development + Process / Macros + OEM Polishing Tools = Peak Performance

It is with the continued innovation of OEM research and development that we will push the limits of digital surfacing and of what we will be able to accomplish, and polishing tools will continue to be an integral part of that process. Nicolas Kane, consumables product manager, North America, Schneider Optical Machines Inc.


CURRENT ISSUE


May/June LabTalk 2017