The Container Manufacturing Process: A Step-by-Step Explanation

Shipping containers are everywhere. They're found on ships, trains, and trucks, transporting goods around the world; they're used to store commercial and personal items; they're converted into homes and hotels; and they're even transformed into rentable storage facilities.

 

Building these massive steel containers, capable of withstanding harsh weather and environmental hazards, is no easy feat. This blog post will explore how, where, and when shipping containers are built.

 

The Container Manufacturing Process

 

You might be surprised to learn that shipping containers aren't entirely machine-made, but require a significant amount of manual labor. Here are the detailed steps involved in the manufacturing process:

 

Step 1: Wall Panels

The construction of a shipping container begins with the wall panels. Large steel sheets are cut into thinner pieces, then sandblasted and primed to remove dust and other contaminants. They are then corrugated, which not only strengthens the walls but also gives the container its characteristic wavy texture. Finally, the corrugated panels are welded to a tubular frame.

 

 

Step 2: Floor Frame Assembly

The floor frame primarily consists of two longer I-beams perpendicular to each other. Shorter I-beams are then welded between the longer ones, forming a flat base. After welding, the floor frame is ground down using a grinding wheel to remove rough welds.

The flooring is pressure-treated with FDA-approved chemicals, including insecticides and preservatives, to ensure the safety and longevity of the wooden floor.

 

Step 3: Doors and Corner Posts

Once the side panels of the container are complete, the front and back panels are constructed. Like the side panels, the doors are primarily made of corrugated steel sheets. After being cut to the required size, the corrugated sheets are encased in square steel tubing.

The doors are installed onto the floor frame, followed by the wall panels. The corner posts, walls, and doors are then welded together, and finally, the roof panel is assembled and installed.

 

Step 4: Completing the Box

The basic box structure is now complete. Cranes lift the door frame onto the floor frame and weld it into place. The wall panels are then lifted and welded, followed by the roof panel.

 

Step 5: Primer and Topcoat

Once the container's frame structure is complete, it needs to be coated with primer and topcoat to protect it from harsh environmental conditions. The primer (also called the base coat) is the first layer of paint sprayed onto the container. It ensures that subsequent coatings adhere better to the container and also provides an additional protective layer.

 

After the primer dries, the container is sprayed with multiple layers of paint. Multiple layers of paint ensure the container is protected from harsh environments such as salt and water during sea transport.

 

The floor panels are coated with varnish to prevent water and insect damage to the wood, and then installed within the frame. Finally, rubber seals are fitted to the doors, and the bottom of the container is waterproofed.

 

Step 6: Floor Installation

Now, the wooden floor needs to be laid on the floor frame. The container floor consists of six plywood panels. These treated plywood panels are placed inside the container and secured to the steel floor beams with screws.

 

Step 7: Stickers and Markings

The shipping container can now have company stickers and logos applied. They also need to have labels with a unique identification code so that the container can be identified anywhere in the world. This identification code consists of 11 alphanumeric characters, each character corresponding to a meaning.

 

The first three letters identify the owner of the container. The fourth character is the product group code, which can be U, J, or Z.

U = Container

J = Any equipment that can be attached to a container, such as a power unit

Z = Trailer used for transporting containers

 

Characters 5 through 10 form a serial number assigned by the container owner. This serial number is used by the container owner to identify the container. The last character is called the check digit and is used to verify the previous 10 characters.

After the container is labeled, door handles and locks are installed. Rubber seals are then fitted to the doors to ensure they are waterproof.

 

Step 8: Waterproofing and Testing

The final step in the container manufacturing process is spraying a waterproof sealant on the bottom of the container. If no defects or leaks are found, the container is complete and ready to be shipped to its destination.