How are lined containers manufactured?

Lined containers are essential in various industries, offering protection against corrosion, chemical reactions, and other forms of damage. As a leading supplier of lined containers, I am often asked about the manufacturing process. In this blog post, I will take you through the step-by-step journey of how lined containers are manufactured.

1. Design and Planning

The manufacturing process of lined containers begins with careful design and planning. This stage involves understanding the specific requirements of the customer, such as the type of chemicals to be stored, the operating conditions (temperature, pressure, etc.), and the desired capacity of the container.

Engineers and designers work together to create detailed blueprints of the container. They consider factors like the shape, size, and thickness of the container, as well as the type of lining material to be used. For example, if the container will be used to store highly corrosive chemicals, materials like N-PTFE Lined Container, PFA Lined Container, or PTFE Lined Container might be chosen due to their excellent chemical resistance.

2. Material Selection

Once the design is finalized, the next step is to select the appropriate materials for the container and its lining. The outer shell of the container is typically made of metals such as steel or aluminum, depending on the strength and durability requirements. Steel is commonly used for large-scale industrial containers due to its high strength, while aluminum may be preferred for lighter applications.

For the lining, materials like PTFE (Polytetrafluoroethylene), PFA (Perfluoroalkoxy), and N-PTFE are popular choices. PTFE is known for its non-stick properties, high chemical resistance, and low friction coefficient. PFA offers similar properties to PTFE but has better transparency and can withstand higher temperatures in some cases. N-PTFE is a modified form of PTFE with enhanced performance characteristics.

3. Fabrication of the Outer Shell

The fabrication of the outer shell starts with cutting the selected metal sheets to the required size and shape. This is usually done using advanced cutting technologies such as laser cutting or plasma cutting, which ensure high precision and clean edges.

After cutting, the metal sheets are formed into the desired shape of the container. This may involve processes like bending, rolling, and welding. Welding is a critical step as it ensures the structural integrity of the container. Skilled welders use techniques such as TIG (Tungsten Inert Gas) welding or MIG (Metal Inert Gas) welding to create strong and leak-proof joints.

Once the basic shape of the container is formed, additional components such as flanges, nozzles, and supports are attached. These components are essential for the proper functioning and installation of the container.

4. Preparation for Lining

Before applying the lining, the inner surface of the outer shell needs to be properly prepared. This involves cleaning the surface to remove any dirt, grease, or oxides. A common method is sandblasting, which uses high-pressure air to propel abrasive particles onto the surface, creating a rough texture that helps the lining adhere better.

After sandblasting, the surface is thoroughly cleaned again to remove any remaining abrasive particles. A primer may also be applied to further enhance the adhesion between the outer shell and the lining material.

5. Application of the Lining

There are several methods for applying the lining material to the inner surface of the container, depending on the type of lining and the size of the container.

Powder Coating

For PTFE and PFA linings, powder coating is a commonly used method. In this process, the lining material is in the form of a fine powder. The powder is electrostatically charged and sprayed onto the preheated inner surface of the container. The heat causes the powder to melt and flow, forming a continuous and uniform coating. Multiple layers may be applied to achieve the desired thickness.

Sheet Lining

Another method is sheet lining, which is often used for larger containers or when a thicker lining is required. In this method, pre-fabricated sheets of the lining material are cut to the appropriate size and shape and then bonded to the inner surface of the container using adhesives or heat fusion techniques. The seams between the sheets are carefully sealed to prevent any leakage.

Molding

In some cases, the lining material may be molded directly onto the inner surface of the container. This is typically done for complex-shaped containers or when a seamless lining is required. The container is placed in a mold, and the lining material is injected or poured into the mold under high pressure and temperature. The material then takes the shape of the inner surface of the container and hardens to form a solid lining.

6. Quality Control

Quality control is an integral part of the manufacturing process of lined containers. At every stage, from material selection to the final inspection, strict quality control measures are implemented to ensure that the containers meet the highest standards.

During the lining application process, the thickness and uniformity of the lining are carefully monitored. Non-destructive testing methods such as ultrasonic testing or eddy current testing may be used to detect any defects or inconsistencies in the lining.

Once the lining is applied, the container undergoes a series of tests to ensure its performance. These tests may include pressure testing, chemical resistance testing, and leak testing. Pressure testing involves subjecting the container to a specified pressure to check for any leaks or structural failures. Chemical resistance testing is done by exposing the lining to the chemicals it will be used to store to evaluate its resistance.

7. Finishing and Assembly

After passing the quality control tests, the container undergoes finishing processes. This may include painting the outer surface of the container to protect it from corrosion and improve its appearance. Labels and markings are also applied to provide information about the container, such as its capacity, operating conditions, and safety instructions.

Finally, any additional components such as valves, gauges, and fittings are installed. The container is then ready for delivery to the customer.

8. Installation and After-Sales Support

As a supplier, we also offer installation services to ensure that the lined containers are installed correctly and safely. Our team of experienced technicians will work closely with the customer to ensure that the container is installed according to the design specifications and local regulations.

In addition to installation, we provide comprehensive after-sales support. This includes regular maintenance, repair services, and technical assistance. Our goal is to ensure that our customers get the most out of their lined containers and that they operate efficiently and safely throughout their lifespan.

Contact Us for Your Lined Container Needs

If you are in the market for high-quality lined containers, we would be delighted to assist you. Our team of experts can help you select the right type of container and lining material based on your specific requirements. We offer a wide range of lined containers, including N-PTFE Lined Container, PFA Lined Container, and PTFE Lined Container.

Contact us today to discuss your project and get a free quote. We look forward to working with you to provide the best lining container solutions for your business.

References

• "Handbook of Chemical Resistance" by Carl A. Harper
• "Plastic Materials and Processes: A Concise Encyclopedia" by Seymour S. Kistler and L. Neil Smith
• "Corrosion Engineering" by Fontana and Greene