PBL film with EVOH, a remarkable product in the packaging industry, combines the excellent properties of PBL film and the high - barrier performance of EVOH. As a supplier of PBL film with EVOH, I am excited to share with you the detailed process of how this product is made.
Raw Material Selection
The first step in making PBL film with EVOH is the careful selection of raw materials. For PBL film, we choose high - quality polymers that offer good mechanical properties, such as flexibility, strength, and tear resistance. These polymers are sourced from reliable suppliers who adhere to strict quality control standards.
EVOH, on the other hand, is a copolymer of ethylene and vinyl alcohol. It is known for its outstanding oxygen barrier properties, which are crucial for preserving the freshness and quality of packaged products. We select EVOH resins with appropriate ethylene content based on the specific requirements of the final product. The ethylene content affects the balance between gas barrier performance and processability. A lower ethylene content generally provides better oxygen barrier properties, but it may also make the resin more difficult to process.
Mixing and Compounding
Once the raw materials are selected, they are mixed and compounded. The PBL polymers and EVOH resin are fed into a compounding extruder. Inside the extruder, the materials are heated and melted. The temperature and screw speed are carefully controlled to ensure uniform mixing of the two components.
During the compounding process, additives may also be incorporated. These additives can enhance the performance of the film in various ways. For example, antioxidants can prevent the degradation of the polymers during processing and storage, while slip agents can improve the surface smoothness of the film, making it easier to handle and process on packaging machines.
Extrusion
After compounding, the molten mixture is extruded through a die to form a film. There are different types of extrusion processes, such as cast extrusion and blown extrusion.
In cast extrusion, the molten polymer is extruded through a flat die onto a chill roll. The chill roll cools the film rapidly, giving it a smooth surface finish. Cast extrusion is suitable for producing films with high clarity and uniform thickness.
Blown extrusion, on the other hand, involves extruding the molten polymer through a circular die. Air is then blown into the center of the extruded tube, expanding it into a bubble. The bubble is cooled and flattened to form a film. Blown extrusion can produce films with a high degree of flexibility and strength, and it is often used for applications where a high - volume production of films is required.
Orientation
To improve the mechanical properties of the PBL film with EVOH, the film may undergo an orientation process. Orientation can be either mono - axial or bi - axial.
In mono - axial orientation, the film is stretched in one direction, typically the machine direction. This process aligns the polymer chains in the stretching direction, increasing the strength and stiffness of the film in that direction.
Bi - axial orientation involves stretching the film in both the machine direction and the transverse direction. This results in a film with balanced mechanical properties in both directions. Bi - axially oriented PBL film with EVOH has excellent tear resistance, puncture resistance, and dimensional stability.
Printing (Optional)
If the customer requires a printed PBL film, a printing process can be added. Printed PBL Film can be achieved through various printing methods, such as flexographic printing, gravure printing, or digital printing.
Flexographic printing is a popular method for printing on flexible packaging films. It uses a flexible relief plate to transfer ink onto the film. This method is suitable for high - volume production and can produce high - quality prints with a wide range of colors.
Gravure printing, on the other hand, uses engraved cylinders to transfer ink onto the film. It offers high - resolution prints and is often used for applications where a very high - quality print finish is required.
Digital printing is a relatively new technology that allows for on - demand printing with variable data. It is suitable for short - run production and can produce customized prints with high accuracy.
Lamination (Optional)
In some cases, the PBL film with EVOH may be laminated with other materials to enhance its performance. Lamination can be done using adhesives or extrusion lamination techniques.
Adhesive lamination involves applying an adhesive between two or more layers of film and then pressing them together. This method can be used to combine the PBL film with EVOH with other films, such as polyethylene or polypropylene, to improve the barrier properties, heat - sealability, or printability of the final product.
Extrusion lamination, on the other hand, involves extruding a molten polymer between two layers of film and then pressing them together. This method is often used for high - speed production and can provide a strong bond between the layers.
Quality Control
Quality control is an essential part of the manufacturing process. At every stage of production, the film is inspected for various quality parameters, such as thickness, width, surface smoothness, and barrier properties.
Thickness is measured using precision instruments to ensure that the film meets the specified requirements. Width is also checked to ensure that the film is within the acceptable tolerance range.
The surface smoothness of the film is evaluated using visual inspection and surface roughness measurement. A smooth surface is important for good printability and for the proper functioning of the film on packaging machines.
The barrier properties of the PBL film with EVOH are tested using specialized equipment. Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) are two important parameters that are measured. Low OTR and WVTR values indicate good barrier performance, which is crucial for preserving the quality of the packaged products.
Conclusion
The production of PBL film with EVOH is a complex process that involves multiple steps, from raw material selection to quality control. Each step is carefully controlled to ensure that the final product meets the high - quality standards required by the packaging industry.
If you are interested in PBL Film or PBL Film with Evoh for your packaging needs, we are here to provide you with high - quality products and professional services. We welcome you to contact us for further discussions and to explore potential business opportunities. Our team of experts is ready to assist you in finding the most suitable solutions for your specific requirements.
References
- Packaging Technology Handbook, Third Edition, edited by Wilmer A. Jenkins and James P. Harrington.
- Plastics Packaging: Properties, Processing, Applications, and Regulations, by John F. Robertson.
- Barrier Polymers and Structures for Packaging, edited by Christopher R. Daubert and Timothy J. Foegeding.
