Characteristics of co-extrusion composite cast film production equipment
DATE：2019/8/21 8:44:52 / READ： / SOURCE：This station
The co-extrusion composite cast film production equipment has the following characteristics:
1) Raw material conveying and feeding device. In addition to the automatic feeder, each extruder is equipped with a weight-measuring hopper and is linked with an automatic metering system to automatically control the production line and film thickness. The automatic weight metering system automatically meters, displays, and records the average area quality of each layer of the coextruded composite film.
2) Extruder. A plurality of extruders are arranged in a fan shape centering on the composite die. For the specifications of the extruder, an extruder with a diameter of 45 to 150 mm is generally used, and the adhesive layer is relatively thin, and an extruder having a diameter of 45-65 mm can be selected. Since some high-barrier resins (such as PVDC) are highly corrosive, the extruders used as barrier layers need to use corrosion-resistant materials for the screws and barrels.
The length to diameter ratio (L/D) of the extruder should be selected according to the resin used, such as
L/D=26~28, suitable for PVDC
L/D=28～30, suitable for EVOH, PA6, adhesive resin, high viscosity polyolefin;
L/D=30～33, suitable for low and medium viscosity polyolefin.
3) Composite casting die. The composite casting die includes a split runner device and a slot die. The melt extruded from each extruder first enters the split runner device, is arranged, superimposed, and then enters the slot die extrusion casting according to the hierarchical requirements.
4) Cooling system. Two cooling rolls are commonly used, as well as a cooling system comprising a heating type air knife, a vacuum suction device, a film end positioning device for electrostatic or compressed air, an embossing positioning device and the like. The double cooling roller can respectively cool the two surfaces of the composite film: the first cooling roller has a large diameter, and the surface of the roller is passivated, so that the composite film with different surface features (viscous or slippery barrier film) can be smoothly peeled off; The cooling roller has a small diameter, the surface is hard chrome plated and highly polished; the double cooling roller can adjust the temperature separately, and the temperature accuracy is ±1 °C; the double cooling roller linear velocity can be adjusted separately to form a stable speed difference.
5) Coiling system. Many co-extruded composite cast film production lines have adopted patented technology for automatic coiling without scrap online. The winding method includes surface winding, surface/center winding, center winding, gap winding, etc., and the contact roller is made of high-strength carbon fiber. The winding speed of the production line is 180-500m/min.
1) Raw material conveying and feeding device. In addition to the automatic feeder, each extruder is equipped with a weight-measuring hopper and is linked with an automatic metering system to automatically control the production line and film thickness. The automatic weight metering system automatically meters, displays, and records the average area quality of each layer of the coextruded composite film.
2) Extruder. A plurality of extruders are arranged in a fan shape centering on the composite die. For the specifications of the extruder, an extruder with a diameter of 45 to 150 mm is generally used, and the adhesive layer is relatively thin, and an extruder having a diameter of 45-65 mm can be selected. Since some high-barrier resins (such as PVDC) are highly corrosive, the extruders used as barrier layers need to use corrosion-resistant materials for the screws and barrels.
The length to diameter ratio (L/D) of the extruder should be selected according to the resin used, such as
L/D=26~28, suitable for PVDC
L/D=28～30, suitable for EVOH, PA6, adhesive resin, high viscosity polyolefin;
L/D=30～33, suitable for low and medium viscosity polyolefin.
3) Composite casting die. The composite casting die includes a split runner device and a slot die. The melt extruded from each extruder first enters the split runner device, is arranged, superimposed, and then enters the slot die extrusion casting according to the hierarchical requirements.
4) Cooling system. Two cooling rolls are commonly used, as well as a cooling system comprising a heating type air knife, a vacuum suction device, a film end positioning device for electrostatic or compressed air, an embossing positioning device and the like. The double cooling roller can respectively cool the two surfaces of the composite film: the first cooling roller has a large diameter, and the surface of the roller is passivated, so that the composite film with different surface features (viscous or slippery barrier film) can be smoothly peeled off; The cooling roller has a small diameter, the surface is hard chrome plated and highly polished; the double cooling roller can adjust the temperature separately, and the temperature accuracy is ±1 °C; the double cooling roller linear velocity can be adjusted separately to form a stable speed difference.
5) Coiling system. Many co-extruded composite cast film production lines have adopted patented technology for automatic coiling without scrap online. The winding method includes surface winding, surface/center winding, center winding, gap winding, etc., and the contact roller is made of high-strength carbon fiber. The winding speed of the production line is 180-500m/min.
Author：admin