Plastics News correspondent Roger Renstrom gathered these briefs from Replitech North America, held June 2-4 in San Francisco.
Dow Plastics probes amorphous polymer
Dow Plastics of Midland, Mich., is evaluating a polymer for high-density optical media formats.
Dow's effort involves polycyclohexylethylene. The amorphous polymer may provide a better balance of optical and mechanical properties than the industry standard, polycarbonate.
William Lutz, a Dow technical service and development leader, made a June 4 technical presentation about PCHE at Replitech.
``We will try to give some performance characteristics and how [they will] translate to future industry needs,'' said T.J. Wainerdi, global market manager of optical media.
The material's advantages in optical discs include high light transmission, low-stress optical coefficient, low water absorption, high heat resistance and low specific density, Dow said.
PCHE shows high light transmission across the infrared-laser light spectrum and for the developing blue-green laser light spectrum. Wainerdi said blue-green lasers may fit inside computers in two or three years.
``This new polymer is not to replace PC for current formats, and it never will,'' he said. ``It is being designed for future formats.''
Using a proprietary hydrogenation process, Dow claims it has developed an economical way to make PCHE and control its properties. The molecule has existed for more than 20 years, but hydrogenation difficulties have limited its weight and light transmission characteristics. Since early 1997, Dow has made Calibre 1080 DVD PC for optical media formats.
GE Plastics devising new optical PC grade
GE Plastics is completing development of a new grade of polycarbonate for yet-to-be-introduced optical media applications.
GE Plastics' Optical Media Development Center in Pittsfield, Mass., has been able to run the material on different types of equipment and is validating it in different formats, Clarence Nunn said by telephone. Nunn is GE Plastics' industry manager for global media and data storage.
Potentially, having the material will speed the commercialization process of new optical media, Nunn said. During 1999, replicators of compact discs and digital versatile discs may begin to reach new horizons, including magneto-optical, DVD-RAM and phase-change formats in rewritable and recordable versions.
``Whatever format wins, our PC should work,'' he said.
The new formats may increase a disc's content density eight, 16 or 32 times. GE featured OMDC at Replitech.