Absolutely, it’s not just possible—it’s already being done in many cities around the world. The key is to design the opening shape and size so that only standard bottles and cans fit through, while discouraging or blocking other types of waste. For example, a circular hole of a specific diameter can allow a typical soda can or water bottle to pass, but prevent larger items like fast-food wrappers or bags. Some models even use a “mouth” with a slotted or cross-shaped opening that only accepts the narrow neck of a bottle or the cylindrical shape of a can.
Beyond the physical design, you can add a slight lip or internal baffle to make it harder for people to stuff in non-recyclables. However, it’s important to pair the hardware with clear signage and color-coding (like a blue lid for recycling) to guide users. One practical challenge is that people might still try to force items through—so maintenance and periodic checks are essential.
In practice, many public recycling bins (like those from brands such as CleanRiver or Ecopod) specifically use these tailored openings to improve recycling purity. If you’re designing one for your city or organization, I’d recommend testing a few prototypes to see what works best for your local waste stream. The short answer? Yes, with thoughtful engineering, you can definitely create an opening that encourages bottle and can recycling only.