1.Why is it not recommended to use ordinary cold-rolled coils (such as SPCC) directly?
Structural Strength and Load-Bearing Capacity: The strength of cold-rolled coils (low-carbon steel) is more than sufficient and can be met through reasonable structural design (such as adding bending ribs or tubular structures).
Weather Resistance and Rust Prevention: This is the biggest issue! Ordinary cold-rolled coils will rust rapidly when exposed to sun and rain outdoors, severely affecting aesthetics and structural safety. Park environments also have corrosive factors such as acid rain and de-icing salt (in northern regions).
Aesthetics and Maintenance: Rust requires frequent grinding and painting, increasing the maintenance cost of public facilities.
Safety: Burrs from rust can scratch users, and severe rust can weaken the structure.
2.What are the advantages and disadvantages of using hot-dip galvanizing to make bench frames?
Excellent corrosion resistance, with an outdoor lifespan of 10-20 years or more. The coating is thick and has strong adhesion, covering welds and edges. It is the standard corrosion protection process for outdoor steel structures.
However, it is more expensive, has zinc bloom and slight unevenness on the surface, and comes in a single color (silver/gray).
3.What are the advantages and disadvantages of electro-galvanizing + powder coating/painting?
Advantages: Aesthetically pleasing, customizable colors (such as dark green, coffee, and other colors commonly used in parks). The coating provides double protection.
Disadvantages: Overall corrosion resistance is slightly inferior to hot-dip galvanizing; if the coating is damaged, the protection time of the underlying electroplated zinc is limited.
4.Why not just use other materials?
Cast iron: Heavy, retro, and extremely durable, but expensive, complex in design, and prone to breakage.
Stainless steel (e.g., 304): A high-end choice, requires no coating, aesthetically pleasing, maintenance-free, and extremely corrosion-resistant. However, the material cost is 3-5 times that of galvanized steel, and it is slightly more difficult to process.
Aluminum alloy: Lightweight, rust-resistant, and modern, but relatively low strength, expensive, and feels less substantial.
Wood/Wood-plastic composite: Primarily used for chair seats and backrests; insufficient strength as a support frame, requiring combination with a metal frame.
5.What suggestions do you have for the processor?
Never deliver pre-fabricated bare steel supports directly to the park.
All welding, cutting, and drilling processes must be completed before applying overall hot-dip galvanizing or spray coating to ensure that every section and gap is protected.