The wall panels for shipping containers are made of corrugated COR-TEN steel. Corrugation is the process of folding sheet metal so that it has ridges and grooves to increase its rigidity and strength. Corrugated steel is able to withstand more weight without bending — a crucial quality for shipping containers, which are routinely stacked on top of each other throughout the shipping process.
Shipping container manufacturing is no simple feat. It requires a specialized facility and a large team to craft the containers. Once built, there are multiple waves of testing to complete before the shipping container manufacturer deems it ready to send out into the world.
Here are just some of the steps in shipping container manufacturing.
Step 1: Wall Panels
The shipping container manufacturing process begins with the wall panels. Steel sheets are sandblasted, primed and then corrugated, giving them that iconic “rippled” texture.
The steel sheets are then welded together to create larger wall panels. Then, tubing is added to the ends of the panels. This will help connect the shipping container’s roof and floor later on.
Step 2: Floor Framing
Once the wall panels are done, the shipping container manufacturer will build the floor frame. Large and small I-beams are welded to form the frame of the floor. I-beams are steel beams frequently used in construction, as they add strong structural support and offer good resistance against bending.
Shipping containers are designed to carry tons of cargo, ranging from consumer goods to heavy machinery. Standard 20ft shipping containers, for example, have loading capacities of 62,016 lbs/28,130kgs. I-beams are excellent shipping container materials because they can help the floors hold that cargo without bending or breaking.
Step 3: Doors
After the floor framing, it’s time to tackle the doors. Shipping container doors are made of steel panels that sit inside a frame of square steel tubing. A rubber seal is wrapped around the edges of the doors to guarantee that they are — and remain — watertight.
Step 4: Corner Posts
Corner posts (also known as corner fittings) are welded to the I-beams of the floor frame. When shipping containers are stacked on top of each other, their corner posts line up. The posts need to be structurally sound and durable so they can hold up the weight of the containers above them without bending or bowing.
Corner posts are also essential for easy transportation. Cranes at ports and shipping yards can lift the container by the corner posts and move it safely to another location.
Step 5: Assembly
The next step of the shipping container manufacturing process is assembly. The door panels and the side-wall panels are placed into position on the floor frame and welded into place. A roof panel is lowered on the top and welded shut, enclosing the structure.
Step 6: Painting
Once the structure is built, it needs to be primed and painted. Painting doesn’t just give the container a “finished” look — it has a practical use, too. Painting a shipping container provides additional layers of protection for the shipping container’s raw structure. This helps to maintain the integrity of the shipping container’s steel for as long as possible.
Step 7: Flooring-container plywood flooring from Suyee 3S Global Containers
A layer of wooden flooring is placed over the steel floor frame and screwed in. This shipping container material is treated with a protective coating to prevent pest infiltration and water damage.
Step 8: Hardware
The shipping container manufacturer attaches hardware — like door handles and locks — to the door panels. (Additional hardware, such as bolt-on locks, can be added post-purchase using a container modification kit).
Step 9: Labels
Labels for identification codes, logos and safety instructions are added to the container.
Step 10: Waterproofing
A waterproof sealant is also added to the bottom of the container. Once applied and dried, the container goes through a waterproofing test. During the test, the container is soaked in water and then inspected for any vulnerabilities. If it’s proven to be watertight, the shipping container manufacturer deems the product to be ready for use.
