Tamura: The project started by an inquiry from sales, “There's this product called optical duct. Can you make a material to use for it?”

Tamura: The major design company Nikken Sekkei has been developing optical duct systems for the last 15 years, and it has finally reached the level where it is commercially viable. Nikken Sekkei was using an aluminum reflective material made by a German manufacturer in its previous optical ducts. Since the material is very important in this system and there were no domestic manufacturers that could make a similar material, we said, “Let's do it. Let's make a material that can help mass produce ducts inexpensively by using steel sheets.” Because of the high cost of the German aluminum material and the low name recognition of optical ducts, they never became popular.

Tamura: Our strengths in “steel” and “wet process” were the keys. The conventional aluminum reflective material is produced with a dry process so that manufacturing costs are high, and because it is a hard material it is not suitable for continuous fabrication and mass production. Changing the material to steel improves the ease of fabricating the ducts and we thought that using a wet process would reduce the cost of evaporation coating. It goes without saying that we had to make the product less expensive than imported products.

Okamura: Basically, the strength of our company is in the wet process, that is, in plating, so this point was clear. Therefore, our goal was to, “Attach a high quality silver coat through plating.” Although this was a difficult hurdle to overcome, we started development knowing that we could win in cost and performance (compared with conventional performance and with our rivals) if we could produce a “plated silver film.”

Ohba: Even at that, we started under the premise, “We can use anything.” For example, “Even evaporation coating is fine.” Evaporation coating film is used in evaporation coating, so our initial approach was, “Can we combine this with lamination to make a product?” However, since a laminate implies, “It's finished once it's applied,” there wasn't much room for improvement so we felt, “It's got to be plating.”

Okamura: It's like taking a test. Getting 80 or 90 points is easy, but when you get closer to 100 points, say from 95 points on, things become more difficult.

Ohba: Our entire team thought, “It has got to be plating. That's what we must concentrate on.” Personally, I was involved in promoting experiments, so we were experimenting on ways to improve silver plating. I've been on the same team as the leader Mr. Okamura since I joined the company, so it's been more a case of “special training” rather than “tutelage.”