Bringing α7 Environmental Performance to Light

Making the most of recycled plastic

Kouji Hisamatsu, Mechanical Design

Sony has been introducing recycled plastic across a broad range of products for some time. In cameras, a variety of parts are already made of recycled plastic. The α7 would be no exception, but it remained challenging to make larger parts out of plastic. According to a structural designer, the team kept asking themselves which α7 parts could be made with recycled plastic.
“Using it in tiny parts would have little impact. We hoped to apply all the advances from our past use of recycled plastic for maximum use this time” said Hisamatsu in mechanical design.
The team set their sights on the camera’s front cover. Could structural refinements enable external parts of recycled plastic instead of highly rigid virgin plastic or similar material? The team rose to the challenge in development.

Kouji Hisamatsu, structural design
α7 parts that contain recycled plastic (from left): screen bezel, back cover, battery lid, and front cover

The culmination of past success, and a promising milestone

A key requirement of structural design to satisfy when using recycled plastic in the front cover was rigidity. Unless the body of an interchangeable-lens camera is highly rigid, a heavy prime lens or massive zoom lens may bend or deform it. How could recycled plastic meet this requirement?
“Our solution was a hybrid structure. Inside, plastic body parts would be reinforced by a stainless steel plate that follows the edges to ensure rigidity.”
The team still had to determine what shape the steel reinforcement should take. After several prototypes were tested, an optimal shape was found – one that ensures ample rigidity for this small but formidable camera.
“Structural design would have been much easier with regular, virgin plastic, but we were committed to using recycled plastic. We knew the insight and experience we gained through α7 cameras would expand our options next time.” Without a doubt, this innovation paves the way for utilizing design to help eliminate use of certain resources in future products.

Hybrid body structure, with a steel-reinforced front cover. Very slim,
yet rigid, thanks to a three-dimensional structure in specific areas.

[Information as of December 2014 by Sony research.]