Mar
2003

On Site: Setting a Unique Course for Poly

Optima president Nick Niejelow.              Photographs by Mike Tamborrino

Optima president and founder Nick Niejelow is a trend-watcher, but that doesn’t make him a trend-follower. Seeing the steady rise in polycarbonate lens sales in the U.S. over the past few years, Niejelow decided it was time to for Optima, a high-index lens pioneer, to enter the polycarbonate lens market. Rather than source product from another manufacturer, Niejelow set out a make his own polycarbonate lenses. Not content to offer a “me too” product, he rethought the polycarbonate lens-making process from the ground up.

The result is Habilis, a unique, two-year-old manufacturing facility in Milford, Conn., where Optima makes its Resolution brand of polycarbonate lenses. Habilis is the Greek word for “the ability to create or innovate.” The 30,000 square foot plant, which includes a Class 1000 clean room and anti-reflective coating facility, is smaller than most other lens plants due to its state-of-the-art equipment and highly automated processes for transporting and handling the lenses. These allow a far greater production capacity because of an extremely low product cycle time. The plant is staffed by a skilled workforce, including a number of optical industry veterans with experience in lens casting and coating.

The major innovation at Habilis is a proprietary, patented technology called ECM-9™ (Extrusion Compression Molding). “It is Optima’s new ECM-9 process, not the material, which sets Resolution lenses apart from all other polycarbonate lenses,” states Niejelow. “The advantage is that it is a highly automated process that allows a three-second cycle time to produce one lens. The process, because of its gentle nature, does not introduce any stress or birefringence into the lens therefore, there is no loss of resolution.”
He asserts that because the lens material has not been subjected to stress the lens is even more impact resistant than other polycarbonate lenses and surpasses them all, with “virtually flawless optics.”

Niejelow notes that the lenses feature an aspheric/atoric design and a 1.2mm center thickness, making them “the thinnest, lightest, clearest polycarbonate lenses out there.”

Resolution lenses are distributed by authorized wholesale laboratories. The product line currently includes finished and semi-finished single vision and progressive lenses. Both tintable and non-tintable lenses are available with and without A-R coating.

1. The Habilis production process begins in this Class 1000 clean room. Here, technicians melt down polycarbonate pellets and cast them into lenses using Optima’s proprietary, patented ECM-9 (Extrusion Compression Molding) process. According to Optima, the automated ECM-9 process—which can produce a lens in a three-second cycle—differs from conventional polycarbonate lens manufacturing because it eliminates stress-induced birefringence in the lens, which can result in changes in power and cause resolution to be significantly decreased.
2. Once the lenses have been cast, they are sent to the racking area, where they are prepared for coating and curing. Here, Habilis lab tech Saba Smajic sets the lenses on the custom-designed, automated racking system.
3. After the lenses have been racked, they are loaded into the coating line, where they are dip-coated in either tintable or non-tintable hard coat. Here, lab tech Malgorzata Kaczmarczyk loads the lenses into the coating line. When finished, a robotic arm moves the lenses from the coating line to the thermal curing line. Following curing, the lenses are un-racked and sent to inspection.
4. In the Habilis A-R chamber, engineer Rob Sherrill prepares a “hood” of lenses for A-R coating. In the background, Niejelow and A-R coating director Glen Koenig check on the coating lab’s yields.
5. When the lenses—both A-R and non-A-R—are ready for packaging, they enter a specially designed final inspection/packaging system developed by Automation and Robotics. First, the center thickness, diameter, power, optics and optical center placement are checked via a fully automated system (see Inset 5a). The lenses are then packaged and ready to be sold as Resolution (see Inset 5b).
6. At the lens inspection stage, Habilis’ Marija Kraguyac checks for any defects in the surface or the coating application.

Poly tech
The key to finishing polycarbonate lenses properly is understanding the properties of the material. Polycarbonate is a thermoplastic material and the polymer, compared to glass or plastic, is “softer.” Consequently, special handing is needed. Paying attention to the following details will have you processing poly like a pro:

• During processing, polycarbonate is more susceptible to heat and scratching. For example, the tightness of the “lens-stops” in a lensometer can scratch poly while leaving glass or plastic unblemished.

• Too much pressure in an edger chuck, which clamps the lens as it is being edged, will scratch or cause pits and other problems, in polycarbonate. Usually, minor adjustments will resolve the problem. Polycarbonate will scratch more easily, but it doesn’t chip or flake like other materials.

• Cutting polycarbonate takes generally between 30 seconds and two minutes longer than plastic, depending on the edger. The lens stock removed is not fine or powdery like plastic. It comes off in spirals, making the swarf “chunkier,” which in turn can “gum” up the cutting devices in the edger. Edging polycarbonate requires more cleaning and general maintenance of the equipment due to the distinctive texture of its swarf.

• Both patternless and pattern edgers can edge polycarbonate as long they have right the cutting tool. With a dry-cut edger (also known as a router system), which uses a blade instead of a wheel, you may have to vacuum out the machine more often when processing poly. Build-up can cause extra heat and warping of the lens.

• The more common edger, a wet-cut, uses diamond roughing, beveling and polishing wheels. Polycarbonate requires a specialized roughing wheel with larger diamond particles placed in a higher concentration. The wheel has to be designed for polycarbonate, because a plastic wheel will gum up too quickly. The polycarbonate wheels have to be cleaned and trued more often.

• Newer, more automated edgers have a special poly cycle. A fine mist of water is sprayed towards the end of the cycle, preventing heat build-up. This critical spray can be circumvented if there’s too much swarf or if the nozzles are clogged or misaligned.

• Older, wet-cut edgers can be retooled to fabricate polycarbonate by replacing the wheel, but older filtration systems can not handle the thicker swarf.

 

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