Plastic film extrusion
DATE：2022/9/26 8:46:24 / READ： / SOURCE：This station
Plastic film extrusion
The temperature of circulating water in the process of separation is too high, or the water ring is poor from the die mouth to the working surface, or there is residue adhering to the roll surface. The ratio between the easily cracked film bubble ratio and the traction speed ratio of the film blank is not properly selected. The length ratio should be: the gap should be adjusted too large. c. The temperature of the melted material is too high. Water d. The easy cracking at the crease of the membrane cylinder is related to the excessive clamping force of the traction roller. ⑨ The strength index of the film decreases a. The plasticizing temperature of the melt is low and the plasticizing is uneven b The ratio between the draft ratio and the expansion ratio of the membrane blank is unreasonable. Generally, the expansion ratio of the membrane blank is too small, so the expansion ratio should be appropriately increased or reduced. c. The mold temperature should be properly increased to reduce the orientation of the film longitudinal molecules. d. The water flow in the cooling ring is small or the water temperature is high. ⑩ Unstable operation of blown film bubble a. Excessive air flow intensity of air flow in production workshop b The air volume of the cooling air ring is too large or the air volume of the air ring is unevenly distributed around the membrane bubble. c. The installation position between the mold, wind ring and traction roller is unreasonable or the concentricity of the three is poor. d. The melting material film forming temperature is on the high side. Hollow board production line www.handern.comThe transparency, thickness uniformity and surface glossiness of the extruded film are better than those of the blown film; Moreover, the rigidity and tensile strength of the film are also slightly improved. Therefore, in the packaging application of various products, the amount is larger than that of blown film; The tape cast film can also be used as a base material for composite films and aluminized films. (1) Polypropylene tape casting film shall be selected as raw material, and resin with melt flow rate (MFR) of 3~12g/10min shall be selected. The modified blend resin, antistatic agent and color masterbatch can be properly added according to the requirements of the application conditions. The best choice for extrusion molding of polypropylene cast film is special cast film molding resin: for example, F850EBAF800E (DF) FC801 produced by Sinopec Shanghai Petrochemical Company; Sinopec Qilu Petrochemical Co., Ltd. produces X37F, T30S, EP2C37F and Fushun Petrochemical Company's EP2C37F. (2) The production line of equipment for film extrusion and tape casting of equipment part C shall be added 6-2 as shown in the figure. The group equipment includes extruder, molding die, cooling and setting roller, corona device, trimming device, winding device, etc. ① A new type of high efficiency screw with a mass mixing head, with a length diameter ratio of ≥ 25 and a compression ratio of 4. ② Three to five layers of filter screen can be used, and the mesh number is 80/120/120/80. The function is to remove impurities in molten materials to ensure product quality. Propose. ③ When the width of forming die products is large, manifold type forming die is used; When the width and size of products are small, coat hanger type molding die is used. The die structure is shown in Figure 6-13~Figure 6-15. (3) Process temperature: barrel process temperature (from feeding section to homogenizing section): 160~stretching 230 ℃, 210~225 ℃, 210~220 ℃. Forming mold temperature: about 210~215 ℃ for the middle part and 215~220 ℃ for the two ends. Cooling roller temperature: 15~20 ℃ (4) Key points of process operation Hollow plate production line www.handern.com
① Pay attention to the influence of the temperature of the plasticizing melt on the quality of the products. The temperature of the melt is on the high side, and the surface of the products has good gloss and high transparency. However, it should also be noted that the impact strength of the product tends to decline when the temperature of the molten material exceeds 290 ℃, and the molten material is easy to decompose.
② The surface temperature of the cooling and setting roller should not be too high, and should be controlled below 25 ℃. The high roller surface temperature will easily reduce the surface gloss and transparency of the products. ③ The cooling and setting roller should have a stable and constant speed. The working speed is fast and slow, so that the thickness and width of the product cannot meet the quality requirements. The traction speed of the product is determined by the apparent quality of the product: the traction speed is too fast, the cooling and shaping effect of the film is poor, and the transparency and glossiness are reduced; The traction speed is too slow, which will affect the production efficiency.
⑤ Note that the distance from the die casting nozzle to the cooling and setting roller should not be too large (generally controlled at about 3mm). If the distance is too large, the surface gloss of the product will also decrease. ⑥ The air jet gap is about 2.5mm, and this gap should not be too large to avoid increasing the F850EBAF800E (DF) FC801 produced by Shanghai Petrochemical Branch of China Membrane Petrochemical Corporation; Sinopec Qilu Petrochemical Co., Ltd. produces X37F, T30S, EP2C37F and Fushun Petrochemical Company's EP2C37F. Hollow board production line www.handern.com
Equipment Part C Film extrusion tape casting equipment Production line equipment includes extruder, molding die, cooling setting roller, corona device, trimming device and winding device. ① A new type of high efficiency screw with a mass mixing head, with a length diameter ratio of ≥ 25 and a compression ratio of 4.
② Three to five layers of filter screen can be used, and the mesh number is 80/120/120/80. The function is to remove impurities in molten materials to ensure product quality.
Propose. ③ When the width of forming die products is large, manifold type forming die is used; When the width and size of products are small, coat hanger type molding die is used. The die structure is shown in Figure 6-13~Figure 6-15. (3) Process temperature: barrel process temperature (from feeding section to homogenizing section): 160~stretching 230 ℃, 210~225 ℃, 210~220 ℃. Forming mold temperature: about 210~215 ℃ for the middle part and 215~220 ℃ for the two ends. Temperature of cooling roller: 15~20 ℃ (4) Key points of process operation ① Pay attention to the influence of the temperature of plasticizing molten material on the quality of products. The temperature of molten material is on the high side, and the surface of products has good glossiness and transparency. However, it should also be noted that the impact strength of the product tends to decline when the temperature of the molten material exceeds 290 ℃, and the molten material is easy to decompose. ② The surface temperature of the cooling and setting roller should not be too high, and should be controlled below 25 ℃. The high roller surface temperature will easily reduce the surface gloss and transparency of the products. ③ The cooling and setting roller should have a stable and constant speed. The working speed is fast and slow, so that the thickness and width of the product cannot meet the quality requirements. ④ The traction speed of the product is determined by the apparent quality of the product: the traction speed is too fast, the cooling and shaping effect of the film is poor, and the transparency and glossiness are reduced; The traction speed is too slow, which will affect the production efficiency. ⑤ Note that the distance from the die casting nozzle to the cooling and setting roller should not be too large (generally controlled at about 3mm). If the distance is too large, the surface gloss of the product will also decrease. ⑥ The air jet gap is about 2.5mm, which should not be too large to avoid adding the membrane hollow plate production line www.handern.com
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