Steel containers, like those used for shipping or storage, are made through several key processes, involving forming, shaping, and assembling steel. Here’s an overview of how they’re made:
- Material Preparation
Raw Materials: High-quality steel is the primary material used. It is typically made from a mix of iron ore, carbon, and other elements that are melted together in a furnace.
Steel Coils or Sheets: The molten steel is cast into large slabs, which are then rolled into coils or flat sheets of uniform thickness. These sheets will eventually be cut and shaped into different parts of the container.
- Cutting
Laser or Plasma Cutting: Large steel sheets are cut into the required sizes for different parts of the container, including walls, roofs, and floors. CNC (computer numerical control) systems are often used to ensure precision.
- Shaping and Forming
Pressing or Stamping: The steel sheets are fed into large presses that bend and shape them into panels with the necessary dimensions. Corrugation (wave-like patterns) is often added to the walls to increase the strength of the container.
Framing: The structural framework (beams and corners) is created from thicker steel components, adding rigidity to the container.
- Welding
Assembly: The individual pieces, such as walls, roof, and floor panels, are then welded together. Robots or skilled welders often use automated welding systems to fuse these parts.
Reinforcement: Additional steel reinforcements may be welded to areas like the door frames, corners, and edges to provide extra strength.
- Surface Treatment
Rust Protection: Once assembled, the container is typically sandblasted to remove impurities and create a smooth surface. It’s then coated with protective layers, such as zinc (galvanizing), to prevent rust.
Priming and Painting: A coat of primer is applied, followed by durable paint to protect the steel and meet the aesthetic or branding requirements of the customer.
- Doors and Finishing
Doors: Steel doors are installed, usually at one end of the container. These doors are fitted with heavy-duty locking mechanisms and rubber seals to ensure a weatherproof and secure closure.
Flooring: The interior floor, typically made of plywood or bamboo, is then installed on top of the steel bottom structure. Some containers may have steel flooring for industrial use.
Ventilation and Accessories: Containers often have small vents for airflow and corner castings for easy lifting and stacking.
- Quality Control and Testing
Structural Testing: Once the container is fully assembled, it undergoes rigorous testing to ensure it meets international standards for strength, durability, and safety. This may include load testing and weather resistance tests.
Final Inspection: A final inspection is carried out to ensure that the container meets specifications and standards, such as ISO certifications.
- Delivery
After passing inspection, the steel container is ready to be delivered to shipping companies or customers for various uses.
This process results in a durable, high-strength container suitable for shipping goods across the world or for other purposes like storage or conversion into modular buildings.