Multi-layer co-extruded cast film Technology

Co-extrusion compounding is to use two or more extruders to respectively extrude the same or different types of resins. In the same die, the composite film is made after confluence.

Driven by the flexible packaging market’s requirements for products with high quality and diversified functions, and driven by resource saving and cost reduction, the advantages of co-extrusion compounding are prominent, and of course there are also disadvantages. The following advantages and disadvantages of co-extrusion compounding Make a comparison.

Advantages of co-extrusion compounding:
1. Reduce the production process and improve the post-processing performance of the film. Multi-layer films can be obtained in one-time production, and the production time and production labor are reduced
2. No adhesives or solvents are needed, which is good for environmental protection, and does not require corresponding devices and thermal energy requirements
3. Thin composite film can be formed, co-extrusion can be processed to form a thin film layer, thereby reducing the consumption of resin, especially to minimize the use of expensive resin;
4. Improve the processing type of the resin. The resin with poor fluidity can be co-extruded with the resin with good fluidity to form a composite film, and the production speed can also be increased. The resin with a tendency to decompose can also be co-extruded by sandwiching its performance resin layers. While reducing defects;
5. The micro-film structure and performance design, which improves the quality of the film, improves the special performance, and can design films with different stability, impact resistance, tear resistance and surface characteristics;
6. Bright colors, each layer can have different colors;
7. There are also a series of advantages such as improving heat sealing strength, lowering heat sealing temperature, and reducing film cost.

Disadvantages of co-extrusion
1. The trimming can not be reused. Different materials are very different. The trimmings are generally not recyclable. Of course, the resin used in the co-extrusion film can be used as the inner layer material when the resin used is the same.
2. The rheological properties of various resins are similar, so that each layer of film can achieve the best, and the replaced resin must have the same rheological properties
3. The molding and processing temperature requirements are high, and the resin temperature of each layer cannot be too different. Therefore, various resin types and grades must be selected
4. Complex equipment, regular inspections and high maintenance requirements
5. It takes a long time to replace the resin, and the loss is large, especially for many varieties, and the disadvantages of small batch production are obvious. This is also one of the important defects in co-extrusion compounding.

The multi-layer co-extruded cast film has developed from 2 to 3 layers at first to 5 to 7 layers at present, and the development is very rapid.

Company Profile

Nanjing Sumino Precision Machinery Co., Ltd. is a high-tech enterprise integrating scientific research, production and sales. It has always adhered to the business philosophy of integrity, equality, and customer benefits. In order to better improve the quality of equipment, it has entered a more professional and standardized Production track. We have established independent research and development technologies for seven categories of equipment including plastic sheet material, casting, bi-stretching, non-woven non-woven meltblown cloth, laminating film composite, recycled granulation environmental protection recycling system and coating machine manufacturing system. The center and production department provide a full set of professional technical solutions to meet the special needs of each customer. Among them, the biaxially oriented film manufacturing system includes: BOPP biaxially oriented film manufacturing system, PVC biaxially oriented shrink film production line, PET biaxially oriented film production line, BOPA biaxially oriented film production line, BOPA biaxially oriented film production line, etc.

Company Address: No. 11, Kaifeng Road, Moling Street, Jiangning District, Nanjing City, Jiangsu Province