• Classification:Industry information
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• Release time:2020-04-02
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【概要描述】1. The film is too sticky and has poor opening

Causes of failure: ① The resin material type is wrong, and it is not a low-density polyethylene resin particle of blown film grade, which contains no opening agent or the content of the opening agent is low; ② The temperature of the molten resin is too high, the fluidity is too high; ③ Blow If the ratio is too large, the opening of the film becomes worse; ④ The cooling rate is too slow, the film is insufficiently cooled, and mutual adhesion occurs under the action of the traction roller pressure; ⑤ The traction speed is too fast.
Solutions: ①Replace the resin raw material, or add a certain amount of opening agent to the bucket; ②Appropriately reduce the extrusion temperature and resin temperature; ③Appropriately reduce the blow-up ratio; ④Increase the air volume, improve the cooling effect, and accelerate the film cooling Speed; ⑤ Properly reduce the traction speed.

2. Poor film transparency

Causes of failure: ① The extrusion temperature is low and the plasticization of the resin is poor, resulting in poor transparency of the film after blow molding; ② The blow-up ratio is too small; ③ The cooling effect is poor, which affects the transparency of the film; ④ In the resin raw material The moisture content is too large; ⑤The traction speed is too fast, and the film cooling is insufficient.
Solutions: ① Properly increase the extrusion temperature so that the resin can be evenly plasticized; ② Properly increase the blow-up ratio; ③ Increase the air volume to improve the cooling effect; Dry the raw materials; ⑤ Properly reduce the traction speed.
3. The film is wrinkled

Causes of the failure: ① The thickness of the film is uneven; ② The cooling effect is not enough; ③ The blow-up ratio is too large, which causes the bubble to be unstable, swinging back and forth, and easy to wrinkle; The film is flattened within the distance, so the film is also prone to wrinkle; ⑤ The pressure on the two sides of the traction roller is inconsistent, one side is high and the other side is low; fold.

Solutions: ①Adjust the thickness of the film to ensure that the thickness is uniform; ②Improve the cooling effect and ensure that the film can be fully cooled; ③Appropriately reduce the inflation ratio; ④Appropriately reduce the angle of the herringbone splint; Ensure that the film is evenly stressed; ⑥ Check the axis of each guide shaft and make them parallel to each other

4. The film has foggy water marks

Causes of failure: ① The extrusion temperature is low and the resin plasticization is poor; ② The resin is damp and the moisture content is too high.

Solution: ① Adjust the temperature setting of the extruder and increase the extrusion temperature appropriately. ② To dry the resin raw materials, it is generally required that the water content of the resin cannot exceed 0.3%.

5. Uneven film thickness

Causes of failure: ① The uniformity of die gap directly affects the uniformity of the film thickness. If the die gap is not uniform, some parts have larger gaps and some parts have smaller gaps, resulting in more or less extrusion volume , The thickness of the formed film is also inconsistent, some parts are thin, and some parts are thick; ②The temperature distribution of the die mouth is uneven, and there are high and low, so that the film thickness after blowing is uneven; ③ Around the cooling air ring Inconsistent air supply, resulting in uneven cooling effect, resulting in uneven film thickness; ④ Inappropriate inflation ratio and traction ratio, making the thickness of the bubble difficult to control; ⑤ The traction speed is not constant and changes continuously, This of course will affect the thickness of the film.

Solutions: ①Adjust the die gap of the machine head to ensure uniformity everywhere; ②Adjust the temperature of the die mouth to make the temperature of the die part uniform; ③Adjust the cooling device to ensure that the air output of the air outlet is uniform; ④Adjust the inflation Ratio and traction ratio; ⑤ Check the mechanical transmission device to keep the traction speed constant.

6. The thickness of the film is too thick

Causes of failure: ① The die gap and extrusion volume are too large, so the film thickness is thick; ② The air volume of the cooling air ring is too large, and the film is cooled too quickly; ③ The traction speed is too slow.

Solutions: ①Adjust the die gap; ②Appropriately reduce the air volume of the wind ring to make the film further inflate, thus making its thickness thinner; ③Appropriately increase the traction speed

7. The thickness of the film is thin

Causes of failure: ①The gap between the die openings is too small and the resistance is too large, so the thickness of the film is thin; ②The air volume of the cooling air ring is too small, the film is cooled too slowly; .

Solutions: ①Adjust the die gap; ②Appropriately increase the air volume of the wind ring to speed up the cooling of the film; ③Appropriately reduce the traction