UNIVERSAL CITY, CALIF. — Replicators face challenges in boosting the efficiency of dual-layer digital-versatile-disc production, according to one injection molder that's gaining proficiency with DVDs.
``Experienced DVD manufacturers know what challenges exist and what to focus on to make the most cost-effective improvements,'' said John Town, Ruckersville, Va.-based vice president of research and development with replicator Nimbus CD International Inc.
Town spoke at the Magnetic and Optical Media Seminar, sponsored by the International Recording Media Association and held Oct. 27-29 in Universal City.
DVD specifications vastly exceed those of compact discs from initial compression, formatting and mastering through molding, printing, bonding, testing and packaging. Replicators juggle process trade-offs involving hotter temperatures, finer pit features and material discoloration and degradation issues.
``When you mold one of these 0.6-millimeter discs, it doesn't want to be as flat as a CD, and it doesn't want to be anywhere as flat as a DVD needs to be,'' he said. A CD is 1.2-millimeters thick; each DVD consists of two bonded 0.6-millimeter discs, both of which can carry data.
A replicator's difficulties multiply in production transitions from CD to single-layer DVD to dual-layer DVD.
``We at Nimbus on many days make more dual- than single-layered discs. That is where the industry is going,'' he said. Single- and dual-layer refers to the number of data layers readable from one side of the disc.
Nimbus has full operational capacity to annually make 20 million DVDs on 14 lines in its Virginia plant, 16 million DVDs on eight lines at sister company Technicolor Video's facility in Camarillo, Calif., and 4 million DVDs on one line at the Nimbus site in Cwmbran, Wales. The firm has Sumitomo injection molding machines operating in the Ruckersville and Cwmbran locations, and Meiki units in Camarillo.
Nimbus' DVD production ``is growing fast,'' but the firm's CD output is still eight to 10 times larger, he said. In September 1996, Nimbus became the first independent DVD producer, and its lines have been running ``flat out since May.''
Eventually, Nimbus will extend its DVD production capabilities to other plants in Provo, Utah, and Foetz, Luxembourg.
Town said DVD molding cycles need to reach CD cycle times. He identified dual-cavity machines as a possible solution.
``It makes perfect sense that if your challenge is to make two mechanically identical discs and turn them into one, that you would use a dual-cavity machine to do it,'' he said. ``That is the challenge. Somebody must come forth and meet it.''
Polycarbonate's viability also is an issue.
``We need a molding material that opens up our process window in molding,'' Town said. ``It is a difficult process right now. If materials can be developed to open our process window, it will remove costs, and it will be a good thing for DVD.''
Nimbus managers ``speak very regularly to the PC manufacturers and vendors,'' he said. ``They tell us that there is still room in the development curve for their materials for DVD, and they are coming out with new materials and developments.
``We need a material that is less susceptive to discoloration or degradation at the higher temperatures when a press goes on purge or on hold,'' Town said.
Session moderator Michael Mitchell agreed.
``As a replicator, you are always looking for as much margin in each process as you can possibly attain. With the demands that DVD holds, I think what we are looking for is a high-flow, low-stress material, one that will stay stabilized,'' he said.
``Polycarbonate is certainly the material of choice now, but as a replicator I would challenge the material providers to take up the gauntlet that John has laid down. because there is not much margin in polycarbonate,'' said Mitchell, engineering director at the Terre Haute, Ind., facility of Sony Corp.'s disc unit, formerly Digital Audio Disc Corp.
Replicators will make 64 million video DVDs this year and 430 million annually by 2002, according to the worldwide DVD intelligence report of the IRMA.
``DVD consumers are buying at an annual rate of 15-20 titles,'' said Charles Van Horn, IRMA executive vice president.
Worldwide annual replication of all forms of DVD — read-only-memory, video and audio — will reach 1.28 billion by 2002, the report said.