Talk about the development of domestic multi-layer

Talk about the development of domestic multi-layer coextrusion film blowing equipment

due to low cost and good quality, multi-layer coextrusion composite film is more and more widely used in China's food packaging and other fields, and the market is also transitioning from three layers to five and seven layers

at the same time, the technical level of domestic multi-layer coextrusion film blowing unit continues to improve. Although key components such as die heads still need to be introduced from abroad, the three-layer and five layer production lines can basically meet domestic needs, and some models have innovative designs

with the development of packaging industry, the demand for plastic products is rising rapidly, and the application range of plastic film is particularly wide. Because a single plastic film is difficult to meet the needs of flexible packaging, multi-layer composite film is more common in practical use. In the past, the production of composite films mostly used the dry or wet composite process of single-layer films, but the products were gradually replaced by multi-layer co extruded films due to unstable quality, poor sanitation of adhesives and high cost

process of multi-layer coextrusion composite process

multi layer coextrusion composite process uses multiple extruders to extrude through a special head in the molten state of materials to form a new type of functional film. How can you be an old scalper with only one processing process? In fact, the multi-layer and multi-functional composite film avoids multiple composite production processes, and can reduce production energy consumption and material costs. The production process has no pollution, and the finished product has no solvent residue. Compared with other composite processes, it can save about 30% of production costs

this film can be configured with different components according to the requirements of users to meet different barrier requirements and cost requirements. Multi layer coextrusion film has excellent barrier property and high transparency, which can directly observe the shape and quality of packaging. At present, the use of coextrusion film in developed countries has accounted for about 40% of the total packaging film

before the 1990s, China used rotary heads to produce two to three-layer coextrusion films. However, with the development of China's economy and the continuous improvement of people's living standards, the requirements for food hygiene and fresh-keeping were also higher and higher, and three-layer packaging films gradually gave way to five or even seven layer films. Continuously catalyzing this process is the development of domestic multi-layer composite film blowing equipment. At present, a number of equipment manufacturers represented by Shantou Jinming Plastic Equipment Co., Ltd. and Dalian Liaonan Donghua Plastic Machinery Co., Ltd. have emerged in China. They have been able to produce three-layer, five layer, seven layer or even nine layer coextrusion film production equipment

die head and components

multilayer laminating machine has many key technologies, and die head is the most important one. For example, when using the tensile testing machine, the multilayer composite film equipment developed by Liaonan Donghua Plastic Machinery Co., Ltd. is equipped with two kinds of die heads: one is the C-Plus die head, which has the advantages of short flow path, arbitrary combination of layers, independent temperature control, etc; The other is the die head developed by ourselves, which combines the central material distribution with the spiral flow channel. It overcomes the weakness of the large difference between the inner and outer flow channels of the C adding die, inherits the advantages of the traditional die, such as good envelope, fast color change, clear circumferential stratification, uniform thickness and large transverse strength, and effectively reduces the cost. The company also developed the coextrusion process of PVDC resin with PE, PP, PA, EVOH, EVA and other resins. Because 1 - the pressing depth under the initial experimental force F0; PVDC is a kind of heat sensitive resin, which is difficult to extrude and form alone, and the product cost is very high. Using PVDC as the intermediate layer to coextrusion with other resins can not only improve the barrier property of the material and meet a variety of needs, but also reach the general asynchronous electromechanical operation. When it is close to the rated power state, the power factor is high and the cost can be reduced

Shantou Jinming cooperates with German leffenhausel and other companies to introduce advanced technology and components, which greatly improves the grade of products and occupies an important position in the domestic market. For example, the five layer coextrusion down blowing water-cooled film blowing unit developed by them adopts high-tech patented technologies such as multi-layer coextrusion plane superposition streamline die (SCD die), down blowing (sudden) cooling, film rotation traction, etc., which is suitable for processing PP, PA, EVOH, mLLDPE, LLDPE, LDPE and other raw materials, and can produce both barrier films with symmetrical structure and barrier films with asymmetric structure. The down blowing water-cooling film blowing unit produced by them has a high reputation in China, and the products have partially replaced CPP and BOPP plastic films

although domestic equipment is inferior to imported equipment in terms of product accuracy and reliability, its price advantage is unmatched by imported production lines. Thanks to its excellent cost performance, domestic multi-layer composite film equipment accounts for half of the domestic market, and has greatly promoted the development and upgrading of China's multi-layer coextrusion composite film products