We have supplied Sedan Production Line for more than 32 years. 

The sedan assembly line is a specific type of automobile production line dedicated to the manufacturing of sedans, which are traditional four-door cars with a separate trunk. Here's an overview of the assembly line process for sedans:

1. **Stamping Process**:
   - **Sheet Metal Preparation**: The process begins with the preparation of sheet metal, sourced from steel or aluminum suppliers.
   - **Pressing**: Large stamping machines, or presses, shape the metal into various components of the car's body, such as doors, hoods, trunk lids, and fenders.

2. **Welding Process**:
   - **Assembly**: The stamped parts are assembled in the welding shop. Hundreds of robots work simultaneously to weld these parts together to form the car's body structure, known as the body-in-white.
   - **Weld Types**: Various welding techniques are used, including resistance welding, MIG welding, and TIG welding, to ensure the strength and integrity of the body structure.

3. **Painting Process**:
   - **Preparation**: The body-in-white undergoes a series of cleaning and preparation steps to ensure a smooth surface for painting.
   - **E-coat**: An electrocoating process is used to apply a primer that helps prevent rust.
   - **Paint Application**: The car body is then painted in a series of coats, including basecoat, clearcoat, and finally a clear protective layer. This is often done in a dust-free environment to ensure a high-quality finish.

4. **Assembly Process**:
   - **Interior and Exterior Trim**: The sedan moves to the assembly line where the interior components such as seats, dashboard, and carpets are installed. Exterior components like wheels, tires, and glass are also fitted.
   - **Powertrain Installation**: The engine, transmission, and other drivetrain components are installed.
   - **Chassis and Suspension**: The chassis, which includes the suspension system, brakes, and fuel tank, is assembled and attached to the body.

5. **Final Testing and Quality Control**:
   - **Testing**: Once assembled, the sedan undergoes a series of tests to ensure all systems are functioning properly. This includes engine performance tests, electrical system checks, and emissions testing.
   - **Quality Inspection**: A thorough visual and mechanical inspection is conducted to ensure the car meets the manufacturer's quality standards.

6. **Final Touches**:
   - **Detailing**: The car is cleaned and detailed, both inside and out, to prepare it for delivery to the dealership.

7. **Delivery**:
   - **Logistics**: The finished sedans are then transported to dealerships, where they are sold to customers.

The sedan assembly line is highly automated, with advanced robotics and computer-controlled systems ensuring precision and efficiency. The entire process is designed to be as streamlined as possible to produce high-quality sedans at a competitive rate.