A proprietary laminating process developed by Optimanufacturing of Green Bay, Wisconsin, allows the company to produce the CDfender®, a new product designed to protect the surface of compact discs (CDs).
The idea originated with Trevor Burroughs, technical director at Optidisc Inc., London, England. After intensive months of studying CD technology Burroughs came up with the idea for a clear polycarbonate film that would have the same properties as the CD itself, allowing the laser to read through the film.
Optimanufacturing's Vice-President of Manufacturing John Brabender explains the three-part product, "The polycarbonate is actually the product itself. This particular polycarbonate is very unique in that it's an optical grade. It doesn't have any imperfections that could bend the light going through it, so the product does not affect the audio or visual quality of the CD."
Although the company purchases pretreated film for their unique application, Brabender says that treatment levels on pretreated film are not stable, "We treat in-line for uniformity in the lamination process." Two different coatings are used, one for each product side. The layer on side two also protects the "adhesive-like" substance that adheres the disc to the CD.
Brabender explains "You can call it an adhesive, but it's not a true adhesive because of its nature. It's a solvent-based material that we call an optical couplant....It really only sticks very smooth things to each other, which is the polycarbonate film and the CD itself."
"We treat in-line for uniformity in the lamination process."- John Brabender
The lamination process
There are two separate lamination steps, both occurring on laminating lines designed and built by Integrated Design (IDC). In the first step, one of the polyester layers is coated and then laminated to the PC film on a 62 inch wide flexographic coater. The film is then slit into three rolls on equipment manufactured by Parkinson.
The second laminating step takes place in a class 10,000 clean room. This lamination is especially important, as it applies the proprietary adhesive-like substance that will adhere the product onto the CD.
"Those slit rolls are taken into a separate machine," says Brabender, "which is a 20 1/2 inch wide solvent coater/laminator located in the clean room. That two part lamination is coated again, and the third polyester layer is laminated to that. The finished roll is taken to the die-cutter where it's printed one color, both sides, and die-cut." The IDC equipment runs at 300 fpm and uses all ultraviolet flexo inks.
Treaters have key role
Throughout the process, all three layers are treated selectively for adhesion using two Universal Roll corona treating stations from Enercon.
"We want the coatings to stay with a particular layer, because when you peel apart the product and throw away the polyesters, one coating is designed so it will stick to the polyester only and be thrown away. The other one is designed so it will stick to the polycarbonate, so when the polyesters peeled off, the coating doesn't come off with it. The corona treatment is key for that."
Having produced millions of CDfender® pieces in its first year Optimanufacturing already has plans for a new product for DVDs called DVDfender®.
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Optimanufacturing was established in 1999 as a joint venture between Optidisc and Integrated Design (IDC).