Transparent olefins offer electro-optics benefits

Edited by the Engineeringtalk editorial team Dec 14, 2006

Fosta-Tek Optics has begun commercialisation of a new class of thermoplastic olefins for precision electro-optics applications

The new transparent olefin materials offer weight and manufacturing cost advantages compared with glass, as well as performance advantages over other thermoplastics.

Fosta-Tek will showcase a number of transparent olefinic optics at the Pacific Design and Manufacturing Show in February 2007 in Anaheim, CA, USA.

"We've used these materials successfully in a number of proprietary military applications", said Jim LeBlanc, Vice President of Fosta-Tek, "and are now looking at a number of commercial applications as well".

Typical precision electro-optics applications include camera lenses, military optics for night vision and sighting systems, and miniaturised display optics.

The new class of materials are amorphous, transparent copolymers based on cyclic and linear olefins with properties that can be varied over a wide range.

They have a high Abbe Value of over 50, which is 20 more than thermoplastics such as polycarbonate and polyester.

"This allows for building optics with low chromatic aberration typical of optical glass", said LeBlanc.

"Another benefit is the index of refraction, which at 1.53 is closer to crown glass than other thermoplastics".

"This means minimal design changes are needed to incorporate olefin based optics as a replacement for glass".

Other benefits of the new transparent olefin polymers include significantly lower manufacturing costs for optics compared to diamond turned glass or thermoset plastics.

Lower weight significantly reduces the moment of inertia in display opto-electronics compared to glass, and high Abbe values result in birefringence.

"For an optical grade of thermoplastic, we haven't found anything better", said LeBlanc.

Transparent olefins offer low moisture absorption and processing temperatures similar to other transparent thermoplastics.

The ability to maintain stable performance characteristics over a broad range of temperature (up to 340F) and relative humidity versus other thermoplastics reduces the variation in focusing/image quality that can be a problem when converting glass optics to other families of thermoplastics.

Improved transmission rates of up to 92 percent are similar to crown glass, and greater than the 88 to 89 percent for traditional thermoplastics, such as PC, acrylic, and polyester.

Different grades of transparent olefins are widely used in applications ranging from blister packs and flexible films for food and healthcare products to prefillable syringes, vials and ampoules, and diagnostic articles such as microtitre plates, cuvettes and lab CDs.

Fosta-Tek Optics specialises in the design and manufacture of polymer based optical components and coatings for OEM customers.

A one stop shop for the design and manufacture of optical components, Fosta-Tek is a leading North American source for military, safety and consumer lenses, as well as a range of industrial optics.

Fosta-Tek's innovative chemical coatings and integrated moulding operations provide economical solutions for high volume requirements.

Privately owned and headquartered in Leominster, MA, the company is ISO 9001:2000 registered and serves a diverse customer base in industrial, consumer, medical, automotive, homeland security and military markets.