Thick and thin bag production device

Abstract

The invention relates to a thick and thin bag production device which comprises an extruder, a die connected with a discharge port of the extruder, and a standard air ring and an upper traction roller arranged on the upper end of the die; the upper end of the standard air ring is provided with a mold air ring; a through hole for a film bubble crude embryo to pass through is arranged in the middle of the mold air ring; one side in the mold air ring is provided with a cavity communicated with the through hole; the upper end of the cavity is provided with an upper windshield which extends downwards, and the lower end thereof is provided with a lower windshield which extends upwards; a buffer air duct is formed between the upper and the lower windshields; the mold air ring is provided with an air inlet hole of a connecting air pipe; the air inlet hole and the cavity are communicated; and the gas enters the cavity through the air inlet hole, and is blown to the film bubble crude embryo in the through hole from the buffer air duct. The mold air ring is used to control the thickness of a side wall of a film bubble, the air outlet of the air pipe is not arranged directly to one side of the film bubble crude embryo but is blown to the film bubble crude embryo through the buffer air duct, so that the thickness of the thin side and the thick side of a produced thick and thin bag is uniform, and the strength is good.

Description

technical field [0001] The invention belongs to the field of plastic film bag manufacturing and relates to a thick and thin bag production device. Background technique [0002] At present, in the production equipment used in the production of plastic thick and thin bags, there are mainly two methods for controlling the wall thickness of plastic thick and thin bags. One method is to control the gap between the inner and outer molds of the plastic thick and thin bags. The main problem of this method is: when the center of the inner mold shifts, the radial gap between the inner and outer molds changes unevenly and symmetrically along the circumferential direction, and the gap between the thick side and the thin side has the thickest point and the thinnest point, thus producing Thick and thin plastic bags with thick and thin film walls are uneven; the second method, in view of the technical defects of the first method, adds an air ring on the upper end of the standard air ring, ...

AI Technical Summary

Problems solved by technology

[0002] At present, in the production equipment used in the production of plastic thick and thin bags, there are mainly two methods for controlling the wall thickness of plastic thick and thin bags. One method is to control the gap between the inner and outer molds of the plastic thick and thin bags. The main problem of this method is: when the center of the inner mold shifts, the radial gap between the inner and outer molds changes unevenly and symmetrically along the circumferential direction, and the gap between the thick side and the thin side has the thickest point and the thinnest point, thus producing Thick and thin plastic bags with thick and thin film walls are uneven; the second method, in view of the technical defects of the first method, adds an air ring on the upper end of the standard air ring, on the side of the thick embryo of the film bubble, There is an air duct on the side of the air ring, and the wind in the air duct is blown radially from the rough film bubble to the thick film bubble. The air pressure of the air duct is used to control the wall thickness of the thick side of the thick and thin bag, that is, a part of the air duct is cooled. The side membrane bubble wall is cooled and formed quickly, so the wall thickness

On the other side, the bubble wall without air duct cooling cools slowly, and continues to be drawn and stretched by the upper traction roller. The thickness of the bubble wall is thin and forms bubbles with different thicknesses on both sides. This method is an improvement over the first method. , but because the air outlet of the air duct is directly aligned with the rough side of the bubble, the bubble wall near the air outlet of the air duct receives the largest wind pressure and air volume, the cooling speed is the fastest, and the wall thickness is the thickest. The film bubble wall far away from the air outlet of the air duct, due to the weakening of the wind pressure and air volume, the cooling speed slows down, so the wall thickness gradually becomes thinner; in addition, the air outlet of the air duct is set freely, and the upper and lower ends of the air ring are not blocked , the wind pressure and air volume in the cooling area are easily disturbed by the external air flow and change at any time. Therefore, the thick and thin bags produced by this wind ring control device have uneven wall thickness on one side of the thick side, which affects its strength. The ratio of thickness to thickness can only reach 1:1.5~1:2

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