That's an excellent and practical question! For a trash can that will live outdoors in a public park year-round, the material choice is critical for longevity, cost-effectiveness, and maintenance. The top contenders are heavy-duty plastic (polyethylene) and powder-coated or stainless steel.
Heavy-Duty Plastic (Rotomolded Polyethylene) is often the top choice. These bins are rotomolded—a process that creates a seamless, thick, and incredibly tough shell. The advantages are significant: they are naturally rust-proof, resistant to dents, and the plastic is non-porous, making graffiti easier to remove. They are also lighter than metal, which simplifies installation and moving for cleaning. High-quality polyethylene can withstand intense UV rays without significant fading or becoming brittle. The main drawback is that extreme heat can cause warping, and determined vandalism might crack them.
Powder-Coated or Stainless Steel offers superior strength and a more premium, permanent look. Stainless steel, particularly grade 304 or 316, is highly corrosion-resistant and incredibly durable against impacts and vandalism. Powder-coated steel provides a thick, baked-on finish that protects against rust and allows for color matching to park decor. The downsides are weight (making them hard to move), cost, and the potential for the coating to chip over time, which can lead to rust if not maintained. They can also get very hot in direct sun.
For a public park, heavy-duty rotomolded plastic frequently wins the balance. Look for features like reinforced lids, sturdy mounting options, and integrated ashtrays. The key is selecting a commercial-grade bin from a reputable supplier, not a residential model. It should be designed to handle constant use, harsh weather, and the occasional abuse, all while keeping maintenance costs low for the park staff.