Sigma’s Decision: 40% Bio-Based Content Without Mold Changes

Yoshiaki Saka
Section Chief, Product Development Division , Sigma Corporation

Sigma Corporation, a global leader in optical products, is accelerating efforts to reduce its environmental footprint as part of its corporate responsibility. While plastic reduction in packaging has advanced, introducing sustainable materials into the products themselves has posed significant technical barriers.

Sigma Corporation is an optical equipment manufacturer that develops, produces, and sells interchangeable lenses and digital cameras. Centered on its Aizu plant in Fukushima Prefecture, Sigma has built a compact, integrated domestic production system supported by a streamlined supply chain primarily within the Tohoku region—enabling the company to consistently maintain world-class performance and quality.

Around 2023, Sigma began accelerating company-wide initiatives to reduce environmental impact, alongside preparations for its Visual Identity (VI) refresh planned for 2025. While efforts such as reducing plastic in packaging were progressing, the product development organization also began exploring whether more sustainable materials could be incorporated into the products themselves. Initially, recycled plastics were considered a leading candidate. However, Sigma faced hurdles unique to an optical equipment manufacturer.

“If there is something development can do for sustainability, it is ultimately a change in materials. We initially explored recycled materials, but the biggest issue was precision,” says Mr. Saka. “Components used in our interchangeable lenses require extremely high, micron-level precision. Recycled materials tend to show greater lot-to-lot variation in material properties, and because their shrinkage behavior differs from existing materials, the same molds cannot be used. We would have to rebuild and fine-tune molds specifically for recycled materials—and we were not in a position to take on that level of cost and risk.”

In addition, as demand for recycled materials grows—particularly in the automotive industry—Sigma also recognized the risk of future supply constraints. Compared with the automotive sector, Sigma’s production volumes are relatively smaller, raising concerns that securing a stable supply of recycled materials could become difficult over time.

This concern was compounded by the scale of the mold changes required.
“Even if we were to remake the molds for recycled materials, a sudden disruption—‘We can’t deliver any material starting next month’—could bring production to a halt. That would be the most serious impact for the business,” says Mr. Saka. “It would drive up costs while increasing risk. Technically speaking, we had no choice but to determine that a full transition to recycled materials would be difficult.”

While aiming to advance sustainability, Sigma could not compromise on precision or secure, stable material sourcing—driving the search for a viable solution.

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