EVA for solar cell encapsulation is based on EVA (vinyl acetate content of 30-33%), supplemented by several modifiers, generally including EVA resin, cross-linking agent, ultraviolet light absorber, antioxidant (or heat-resistant) Aging agent), UV stabilizer, plasticizer, tackifier, etc., are extruded and cast into film products. The product is heated during the encapsulation of solar cells, resulting in a cross-linking reaction, and is a thermosetting hot-melt adhesive film. The cured film has relatively high light transmittance, adhesive strength, thermal stability, air tightness and aging resistance. According to the special working conditions of the melt pump for EVA photovoltaic film extrusion production line, Zhengzhou Batte independently developed and produced the melt pump for EVA photovoltaic film, which has the functions of high-precision metering, voltage regulation and boosting. The metering pump is used, and high-precision pressure sensors are installed before and after the screen changer and after the metering pump, and the detected pressure of the pressure sensor and the actual pressure are checked to eliminate errors caused by improper installation and various interferences. Control system to ensure that pressure fluctuation should be controlled within ±0.1MPa.

Features of melt pump for EVA photovoltaic film:

1. The temperature control is electric heating + circulating water temperature adjustment.

The EVA modified adhesive resin must have sufficient time to activate the acid anhydride during co-extrusion to ensure sufficient adhesive force. Therefore, the temperature setting is very important. In order to prevent the degradation of EVA due to excessive processing temperature, the processing temperature should be limited to 238 degrees. The inside of the melt pump for EVA film is designed with circulating temperature-controlled water to adjust the temperature.

2. There is no dead angle in the design of the runner, and the internal circulation runner has a smooth arc transition.

Excessive temperature or dead angle in the extrusion process will cause the EVA resin to stay too long, which may cause the resin to age. Therefore, the retention time will also affect the quality of the film. The design concept of the melt gear pump for EVA film is the same as that of the rubber melt gear pump. There is no dead angle inside, and the circulating lubrication flow channel is uniform and smooth.

3. The temperature of the gear shaft is controlled by circulating water. Gear meshing and conveying resin compound will generate shear heat by itself. In order to avoid excessive temperature rise, the shaft center of the melt gear pump for EVA film is designed with circulating temperature-controlled water, and the shaft head is equipped with a rotary joint.

4. Adopt helical tooth design.

The gears of the melt gear pump for EVA film are meshed with helical teeth, and the meshing runs smoothly. Productivity is increased and shearing is reduced.

5. The seal is a maintenance-free spiral seal.

The melt pump for EVA film adopts the form of screw seal, which avoids the influence of the residue of conventional packing seal on the product.

Melt gear pump structural material for EVA solar film

Pump body: high temperature tool steel, chromium-nickel alloy steel
Gears: high temperature tool steel, nitrided steel
Sliding bearings: high temperature tool steel, other special materials and coatings
Shaft seal: screw seal
Heating system: electric heating
Cooling system: Shaft end cooling system

Zhengzhou Batte is a professional melt gear pump manufacturer, providing various specifications of melt gear pumps for the resin, chemical fiber, rubber and other polymer material industries, and providing various series of melt gear pumps that can meet all polymer working conditions. product. The company provides melt gear pumps with complete specifications: ranging from 0.1CC to 12000CC, and can also be customized according to user needs. info@battemachinery.com

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