CN110065223B

CN110065223B - Plastic film blow molding method

Info

Publication number: CN110065223B
Application number: CN201910467726.9A
Authority: CN
Inventors: 曹玉; 毛潞
Original assignee: Chongqing Ruiting Plastic Co Ltd
Current assignee: Chongqing Ruiting Plastic Co Ltd
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2021-05-28
Anticipated expiration: 2039-05-31
Also published as: CN110065223A

Abstract

The invention relates to the field of plastic film production, and particularly discloses a plastic film blow molding method, which needs to use a supporting block arranged on a frame of blow molding equipment, wherein the supporting block is sleeved on a blow molding machine head; the method comprises the following steps: (1) extruding a thin-walled tube; (2) blowing the thin-wall tube into a thin-film tube; (3) cooling and shaping the film tube; (4) removing static electricity of the thin film tube; (5) the film tube is clamped flatly; (6) drawing the thin film tube; (7) and rolling the film. The step of "film pipe static gets rid of" is passed through to this scheme for the static of film pipe is got rid of, has solved among the prior art film pipe and has rocked and the film pipe surface adheres to the problem of static.

Description

Plastic film blow molding method

Technical Field

The invention relates to the field of plastic film production, in particular to a plastic film blow molding method.

Background

With the progress of human science and technology, plastic films have replaced most of paper packages as packages, the demand of the films is huge, the films are generally produced by blow molding of a flat extrusion blow-up method, in the molding process, raw materials are firstly melted and plasticized in an extruder, the melted raw materials are extruded into thin-walled tubes through a blow molding machine head of blow molding equipment, then compressed air is ejected from a mandrel of the machine head to blow the thin-walled tubes to form film tubes, the film tubes are cooled through a wind ring, the cooled film tubes are clamped and flattened through a herringbone plate to form attached films, and finally the films are drawn to a take-up roll through a drawing roll to be taken up to form film products.

However, the prior art also has the following problems with respect to the blow-molding production of plastic films:

firstly, in the process of forming the film tube, the diameter of the film tube is far larger than that of the mandrel, the expansion of the diameter of the film tube is controlled by the flow and the speed of compressed air blown out by the mandrel, when compressed air clusters blown out by adjacent air outlets on the mandrel reach the surface of the film tube, because the distance blown out by the compressed air clusters is longer, the distance between the adjacent compressed air clusters contacted with the film tube is far larger than that between the adjacent air outlets on the mandrel, and therefore the stretching stress of the film tube in the process of blowing the film tube is not completely uniform.

Secondly, the film pipe is at the forming process, from the thin wall pipe to the shaping film pipe, is pull by the carry over pinch rolls at last, whole process, the ascending traction force of carry over pinch rolls is received to the upper portion of film pipe, the lower part of film pipe receives the holding power that the wind ring blows to the film pipe, the interlude of film pipe receives a plurality of compressed air groups that the mandrel blew out, and this compressed air group is not completely even to the power of applying to the film pipe, therefore the interlude of film pipe appears rocking easily, and then makes the film pipe warp and the quality worsens.

Thirdly, in the process of forming the thin-wall pipe, because the raw material is extruded from a blow molding machine head of blow molding equipment to form the thin-wall pipe, the friction force between the raw material and the blow molding machine head is large, and then static electricity is formed and is attached to the thin-wall pipe, so that the thin-wall pipe can easily adsorb dust.

Disclosure of Invention

The invention aims to provide a plastic film blow molding method, which aims to solve the problems of shaking in the production process of a film tube and static electricity attached to the surface of the film tube in the forming process of the film tube caused by stretching and expanding the film tube only by a mandrel at the inner side of the film tube in the prior art.

In order to achieve the above object, the basic scheme of the invention is as follows:

the plastic film blow molding method needs to use a supporting block arranged on a frame of blow molding equipment, the supporting block is sleeved outside a mandrel of a blow molding machine head and is coaxial with the mandrel, the side surface of the supporting block close to the mandrel is a circumferential surface, a plurality of grooves are arranged on the circumferential surface, balls are arranged in the grooves, the opening size of each groove is smaller than the spherical diameter of each ball, and anti-static liquid is filled in the gap between each groove and each ball; the method comprises the following steps:

(1) extruding a thin-walled tube: adding the raw materials into a machine barrel of an extruder, rotating, extruding, stirring and pushing the raw materials by a screw, and finally extruding the raw materials into a thin-walled tube by a right-angle head, wherein the compression ratio of the screw is 2.8-4.0, and the extrusion temperature of a blow molding head is 160-190 ℃;

(2) and blowing the thin-wall tube into a thin-film tube: compressed air is introduced into the thin-wall pipe, and the thin-wall pipe is blown into a thin-film pipe by the compressed air, wherein the blow-up ratio is 1.2-3;

(3) cooling and shaping the film tube: cooling the film tube by using an air ring with an upper air channel and a lower air channel, wherein the air speed of the upper air channel is higher than that of the lower air channel;

(4) and removing static electricity of the thin film tube: in the upward moving process of the thin film tube, the thin film tube is in contact with the ball bearing with the antistatic liquid on the supporting block, and the static electricity is coated on the outer surface of the thin film tube;

(5) and clamping the film tube: the film tube is clamped flat by a herringbone plate formed by two inclined frames in the shape of an inverted V, and the V-shaped included angle between the inclined frames in the shape of the inverted V is 40 degrees;

(6) drawing the thin film tube: the clamped film tube enters a traction roller to be drawn;

(7) and rolling the film: the film enters the winding roller through the guide roller to be wound and molded.

Compare the beneficial effect in prior art:

firstly, compared with the prior art, the method adds the step of 'electrostatic removal of the film tube', the film tube rubs with the ball bearings in the process of moving upwards under the traction force of the traction roller, so as to drive the ball bearings to rotate, the anti-static liquid is coated on the surface of the film tube in the process of rotating the ball bearings, so that the surface of the film tube is subjected to the electrostatic removal effect, the electrostatic removal is performed after the film tube is cooled and formed, the earlier the electrostatic removal of the film tube is, the less dust is adsorbed by the film tube in the subsequent processes of flattening, traction, rolling and the like, and the improvement of the finished product quality of the film is facilitated.

Second, in the step of "electrostatic removal of the thin film tube", a support block having a circumferential surface is used, which is close to the thin film tube, thereby reducing the shaking of the thin film tube as compared to the prior art.

Further, the cooling and shaping of the thin film tube in the step 3 are adjustable cooling and shaping, the wind ring in the step 3 comprises a wind disk base, an upper wind disk and a lower wind lip, and a plurality of upper wind channels blowing to the thin film tube are arranged on the lower wind lip; the lower air lip is provided with an annular groove, the annular groove is provided with an opening, an adjusting ring is connected in the annular groove in a sliding mode, the adjusting ring is provided with a through hole, and each upper air channel can be communicated with the annular main air channel through the through hole and the opening.

Has the advantages that: through setting up a plurality of wind channels of going up in this step 3 for the cold air that blows to the film pipe blows out simultaneously from last wind channel and lower wind channel, and then makes in the same time, and the area of contact of cold air and film pipe is bigger, makes the cooling rate of film pipe faster, and realizes the selection to going up the wind channel through the adjustable ring, and then controls the air-out angle of the required cold air of film pipe according to the production actual demand of film pipe.

Furthermore, the adjusting ring is sleeved with a rotary table through threads, the rotary table is rotatably connected to the lower air lip, and the rotary table can drive the adjusting ring to move up and down.

Has the advantages that: the adjusting ring is driven by the rotary table to move up and down in the annular groove, so that different upper air channels can be selected; threaded connection makes the transmission of power more steady between carousel and the adjustable ring, is favorable to guaranteeing that the center of adjustable ring does not take place the skew, further is favorable to the cold air to blow to the film pipe uniformly.

Further, while the thin film tube is removed electrostatically in the step 4, the method also comprises a step A of supporting the thin film tube, wherein the supporting block is required to be used in the step A; the supporting shoe is piled up by a plurality of backup pad and is formed, has seted up a plurality of air grooves in the backup pad, forms the arborescent groove between a plurality of air grooves, and the air groove of adjacent backup pad forms the air flue, and the one end equipartition of air flue is on the periphery of supporting shoe, and the air flue end on the periphery of supporting shoe is the branch end of arborescent groove, is equipped with the negative pressure machine in the frame, and the air flue communicates with the negative pressure machine, supports the film pipe through the air flue of taking the negative pressure.

Has the advantages that: the film pipe is at the shaping in-process, and the film pipe outside receives the negative pressure suction that comes from the air flue, and the one end equipartition of air flue is on the periphery of supporting shoe, therefore the film pipe receives the outside pulling force of a plurality of level, and this a plurality of pulling force evenly distributed along film pipe circumference, in addition the film pipe shaping in-process, receives the upward traction force of carry over pinch rolls, therefore this a plurality of pulling forces combine ascending traction force, form the upward holding power to the film pipe promptly, are favorable to the shaping of film pipe.

In addition, the film pipe is at the fashioned in-process, and not only the film intraductal side receives the compressed air that the mandrel blew out and tensile bloated, also receives the negative pressure suction of the air flue of taking the negative pressure in the outside of film pipe, therefore compare in prior art and only make the film pipe tensile bloated by the inboard mandrel of film pipe, the equal atress in inside and outside both sides of film pipe in this scheme for the atress of the intraductal outside and inside both sides of film is more even relatively, and then makes the tensile bloated also more even of film pipe.

Further, the inclined frame in the step 5 is fixedly connected to a chassis which is arranged on the frame in a rotating mode.

Has the advantages that: the herringbone plate formed by the inclined frame is driven to swing through the rotating chassis, so that the thin film tube is driven to slightly swing around the central axis of the thin film tube, and in the process of clamping and flattening the thin film tube through the herringbone plate, the swinging thin film tube is favorable for reducing the probability of uneven local thickness of the thin film tube.

Furthermore, the supporting block and the chassis rotate synchronously, and the rack is provided with a driving unit for driving the chassis and the supporting block to rotate synchronously.

Has the advantages that: the supporting block and the chassis are driven to swing by the driving unit, the structure is simple and reliable, and the occupied area is small.

Further, a step B of detecting the thickness of the thin film tube is also arranged between the step 6 and the step 7, and the step B of detecting the wall thickness of the thin film tube through a thin film tube thickness detection device.

Has the advantages that: the wall thickness of the thin film tube is detected in time through the thin film tube thickness detection device, and the problems of raw material waste and production efficiency reduction caused by unqualified thin film thickness are avoided.

Further, step C and film tube cutting are further included between the step B and the step 7, and the step C cuts the waste material of the film tube and the specific width of the film through a film tube cutting device.

Has the advantages that: and cutting the waste of the film tube and the specific width of the film by using a film tube cutting device, and further preparing for winding a film finished product.

And further comprising a step D of recycling waste materials of the thin film tube between the step C and the step 7, wherein the waste materials of the thin film tube are recycled by a thin film tube waste material recycling device in the step D.

Has the advantages that: after the waste material is not cut, the waste material of the film pipe is timely recycled through the film pipe waste recycling device, and recycling of resources is facilitated.

Drawings

FIG. 1 is a schematic diagram of a forward structure according to an embodiment of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1 in accordance with the embodiment of the present invention;

FIG. 3 is an enlarged view of the portion B of FIG. 1 according to the embodiment of the present invention;

FIG. 4 is a top view of the support block and spindle of FIG. 3;

fig. 5 is a schematic diagram of a forward structure of the thin film tube waste recycling device in fig. 1.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: the device comprises a frame 1, an extruder 2, a blow molding machine head 3, an air ring 4, a supporting block 5, a servo motor 6, a mandrel 7, an air duct 8, an air exhaust pipeline 9, a supporting plate 10, a tree-shaped groove 11, balls 12, a pit 13, a driving wheel 14, a belt 15, an upper air lip 16, an air disc base 17, an upper air disc 18, a lower air lip 19, an annular main air duct 20, a lower air duct 21, a first upper air duct 22, a second upper air duct 23, an exhaust air duct 24, an annular groove 25, an opening 26, an adjusting ring 27, a first through hole 28, a second through hole 29, a rotating disc 30, a heat dissipation hole 33, a thin film tube 34, a herringbone plate 35, a traction roller 36, a wind-up roller 37, a base plate 31, a thin film tube thickness detection device 32, a thin film tube cutting device 38, thin film tube

waste recycling devices

39 and 40, a pair roller 41.

The embodiment is substantially as shown in fig. 1 to 5:

referring to fig. 1, a plastic film blowing method needs to use a blowing device, and the blowing device sequentially comprises a frame 1, an extruder 2, a blowing head 3, a wind ring 4, a supporting block 5, a herringbone plate 35, a traction roller 36, a film tube thickness detection device 32, a film tube cutting device 38, a film tube waste recovery device 39 and a wind-up roller 37 according to the film blowing forming steps.

A mandrel 7 is installed at the center of a blow molding machine head 3, the blow molding machine head 3 is fixedly connected with an extruder 2 through a bolt, a wind ring 4 is fixedly installed on the blow molding machine head 3 through a bolt, a supporting block 5 is rotatably connected on a rack 1, a chute for the supporting block 5 to rotate is formed in the rack 1, a rolling ball convenient for the supporting block 5 to rotate is installed at the bottom of the chute, and the extruder 2, a film tube thickness detection device 32, a film tube cutting device 38 and a film tube waste recovery device 39 are all fixedly installed on the rack 1 through bolts; the drawing roller 36 and the winding roller 37 are rotatably connected to the frame 1.

With reference to fig. 1 and 2, the frame 1 is further fixedly connected with a negative pressure machine through bolts, the wind ring 4 is arranged on the frame 1, the wind ring 4 comprises a wind disk base 17, an upper wind disk 18, a lower wind lip 19 and an upper wind lip 16, the upper wind disk 18 covers the wind disk base 17, the lower wind lip 19 is fixedly connected to the upper wind disk 18 through bolts, the upper wind lip 16 is welded on the lower wind lip 19, and a plurality of heat dissipation holes 33 are uniformly distributed in the upper wind lip 16; an annular main air duct 20 is formed among the air disc base 17, the upper air disc 18 and the lower air lip 19, a lower air duct 21 blowing to the film tube 34 is formed among the air disc base 17 and the lower air lip 19, the lower air duct 21 is communicated with the annular main air duct 20, two upper air ducts blowing to the film tube 34 are arranged on the lower air lip 19, and the two upper air ducts are respectively a first upper air duct 22 and a second upper air duct 23; the annular main air duct 20 is communicated with an air outlet of the negative pressure machine through an air outlet pipeline 24.

The lower air lip 19 is provided with an annular groove 25, the annular groove 25 is provided with an opening 26, the annular groove 25 is connected with an adjusting ring 27 in a sliding manner, the adjusting ring 27 is provided with a first through hole 28 and a second through hole 29 which have different air outlet angles, the first upper air duct 22 is communicated with the annular main air duct 20 through the first through hole 28 and the opening 26, and the second upper air duct 23 is communicated with the annular main air duct 20 through the second through hole 29 and the opening 26.

The adjusting ring 27 is sleeved with a rotating disc 30 through threads, the rotating disc 30 is rotatably connected to the lower air lip 19, and the rotating disc 30 can drive the adjusting ring 27 to move up and down through rotation; the rotary plate 30 is connected with a push handle which is convenient for pushing the rotary plate to rotate manually.

With reference to fig. 1 and 3, the supporting block 5 is sleeved outside the spindle 7 and is coaxial with the spindle 7, and the side surface of the supporting block 5 close to the spindle 7 is a circumferential surface; the supporting block 5 is provided with a plurality of air passages 8, one ends of the air passages 8 are uniformly distributed on the circumferential surface of the supporting block 5, the other ends of the air passages 8 are communicated with an air inlet of the negative pressure machine through an air suction pipeline 9, and negative pressure is formed in the air passages 8.

Referring to fig. 3 and 4, the supporting block 5 is formed by stacking a plurality of supporting plates 10, a plurality of air grooves are formed in the upper and lower surfaces of the supporting plates 10, the air grooves of the adjacent supporting plates 10 form air passages 8, tree-shaped grooves 11 are formed among the air grooves, and the tail ends of the air grooves on the circumferential surface of the supporting block 5 are branch ends of the tree-shaped grooves 11.

The periphery of the supporting plate 10 is provided with a plurality of grooves, the balls 12 are arranged in the grooves, the opening sizes of the grooves are smaller than the spherical diameters of the balls 12, anti-static liquid is filled in gaps between the grooves and the balls 12, the supporting plate 10 is provided with pits 13 and bosses for positioning, the pits 13 and the bosses are in concave-convex fit, positioning and limiting are carried out between adjacent supporting plates 10 through the pits 13 and the bosses, and the adjacent supporting plates 10 are fixedly connected through bolts.

Referring to fig. 1, the chevron plate 35 includes two inclined brackets in the shape of an inverted V, the inclined brackets are welded on a chassis 31 provided with the inclined brackets, that is, the chevron plate 35 is fixed on the chassis 31, the chassis 31 is rotatably connected to the frame 1, a connecting rod is welded between the chassis 31 and the supporting block 5, the chassis 31 is driven by a servo motor 6 provided with the inclined brackets, the servo motor 6 is fixedly connected to the frame 1 through bolts, an output shaft of the servo motor 6 is connected with a driving wheel 14, a belt 15 is wound between the chassis 31 and the driving wheel 14, the servo motor 6 drives the chassis 31 and the supporting block 5 to perform counterclockwise and clockwise cross swinging, and a tension wheel is further provided between the chassis 31 and the.

Referring to fig. 1 and 5, the film tube waste recycling device 39 includes a guide wheel 40, a pair of rollers 41, a double-shaft crusher 42 and a centrifugal blower 43, wherein the waste 44 is cut by the film tube cutting device 38, enters the pair of rollers 41 through the guide wheel 40, is pulled by the pair of rollers 41 to enter the double-shaft crusher 42 for crushing, and the crushed film scraps are pumped to the extruder 2 by the centrifugal blower 43.

The method comprises the following steps:

(1) extruding a thin-walled tube: melting and plasticizing the raw materials in an extruder 2, extruding the melted raw materials into a thin-walled tube by a blow molding machine head 3 of blow molding equipment, wherein the compression ratio of a screw is set to be 3, and the extrusion temperature of the blow molding machine head 3 is set to be 180 ℃;

(2) and thin-wall tube blowing to form thin-film tube 34: compressed air is ejected from a mandrel 7 of the blow molding machine head 3 to blow up the thin-wall tube to form a film tube 34, and the blow-up ratio is set to be 2 during blowing up;

(3) cooling and shaping the film tube 34: when the air ring 4 cools the film tube 34, a worker can select the first upper air duct 22 or the second upper air duct 23 to cooperate with the lower air duct 21 to provide cold air for the film tube 34 according to the actual cooling requirement of the film tube 34.

If the angle of the cold air blown out from the first upper air duct 22 is suitable for the cooling requirement of the film tube 34, the rotating disc 30 is rotated by the push handle, so that the first through hole 28 is aligned with the first upper air duct 22, and the cold air flows through the annular main air duct 20, the first opening 26, the first through hole 28, and is finally blown out through the first upper air duct 22, thereby combining with the lower air duct 21 to realize the cooling effect on the film tube 34.

Similarly, if the angle of the cool air blown out from the second upper air duct 23 is suitable for the cooling requirement of the film tube 34, the rotating disc 30 is rotated by the push handle to make the second through hole 29 align with the second upper air duct 23, and then the cool air is blown out from the second upper air duct 23, so as to combine with the lower air duct 21 to achieve the cooling effect on the film tube 34.

In the process that the air ring 4 cools the film tube 34, the wind speed of the first upper air duct 22 and the second upper air duct 23 is larger than that of the lower air duct.

(4) Support membrane tube 34: in the process of blowing the thin film tube 34, because the outer side of the thin film tube 34 is subjected to the negative pressure suction force of the air passages 8 which are uniformly distributed in the circumferential direction, the thin film tube 34 is subjected to a plurality of tensile forces which are distributed in the circumferential direction and face the outer side of the thin film tube 34, and the air passages 8 are formed by the tree-shaped grooves 11 of the adjacent support plates 10, so that the air passages 8 are also in a tree shape; the tree-shaped air passages 8 enable the negative pressure suction difference generated by any two air passages 8 to be smaller, and further facilitate the uniformity of the stress of the film tube 34. Furthermore, during the shaping of the film tube 34, an upward pulling force is exerted by the pulling roll 36, so that the several underpressure suctions in combination with the upward pulling force, i.e. the upward supporting force against the film tube 34, facilitates the shaping of the film tube 34.

In the process of blowing the film tube 34, not only the inner side of the film tube 34 is stretched and expanded by the compressed air blown by the mandrel 7, but also the outer side of the film tube 34 is subjected to the negative pressure suction of the air duct 8 with negative pressure, so that both the inner side and the outer side of the film tube 34 are stressed, and the stretching and expansion of the film tube 34 are more uniform.

(5) Electrostatic removal of the thin film tube 34: when the film tube 34 is pulled by the pulling roller 36 to move upwards, the film tube 34 rubs against the balls 12 to drive the balls 12 to rotate, and when the balls 12 rotate, the antistatic liquid is coated on the surface of the film tube 34 to remove static on the surface of the film tube 34.

(6) And the thin film tube 34 is clamped flat: the film tube 34 is clamped flat by a herringbone plate 35 formed by two inclined frames in the shape of an inverted V, and the V-shaped included angle between the inclined frames in the shape of the inverted V is 40 degrees.

The servo motor 6 drives the transmission wheel 14 to swing anticlockwise and clockwise in a crossed manner, so that the chassis 31 connected with the transmission wheel 14 through the belt 15 swings, the herringbone plate 35 fixedly connected to the chassis 31 swings, the thin film tube 34 is driven to slightly swing around the central axis of the thin film tube 34, and in the process of clamping and flattening the thin film tube 34 through the herringbone plate 35, the swinging thin film tube 34 is beneficial to reducing the probability of uneven local thickness of the thin film tube 34.

Meanwhile, the chassis 31 is fixedly connected with the supporting block 5, so that the supporting block 5 and the chassis 31 synchronously swing, the rolling frequency of the balls 12 is increased, the electrostatic liquid on the film tube 34 is coated more, and the static electricity on the film tube 34 is further removed.

(7) Drawing the thin film tube 34: the pinched film tube 34 is drawn into a draw roll 36;

(8) and detecting the thickness of the thin film tube 34: detecting the wall thickness of the thin film tube 34 by the thin film tube thickness detecting device 32;

(9) cutting the thin film tube 34: cutting the waste 44 of the film tube 34 and the specific width of the film by the film tube cutting device 38;

(10) membrane tube 34 waste 44 recovery: referring to fig. 1 and 5, the waste 44 is cut by the film tube cutting device 38, enters the pair roller 41 through the guide wheel 40, is drawn by the pair roller 41 to enter the double-shaft crusher 42 for crushing, and the crushed film scraps are pumped to the extruder 2 by the centrifugal exhaust fan 43 for recycling.

(11) And rolling the film: the cut film with a specific width is fed into a take-up roller 37 through a guide roller for take-up forming.

The foregoing is merely an example of the present invention and common general knowledge of known specific structures and features of the embodiments is not described herein in any greater detail. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. A method of blow moulding a plastic film, characterised by: the method needs to use a supporting block arranged on a frame of the blow molding equipment, the supporting block is sleeved outside a mandrel of a blow molding machine head and is coaxial with the mandrel, the side surface of the supporting block close to the mandrel is a circumferential surface, a plurality of grooves are arranged on the circumferential surface, balls are arranged in the grooves, the opening size of each groove is smaller than the spherical diameter of each ball, and anti-static liquid is filled in gaps between the grooves and the balls; the method comprises the following steps:

(3) cooling and shaping the film tube: cooling the film tube by using an air ring with an upper air channel and a lower air channel, wherein the air speed of the upper air channel is higher than that of the lower air channel; the cooling shaping of the film tube is adjustable cooling shaping, the wind ring in the step 3 comprises a wind disk base, an upper wind disk and a lower wind lip, and a plurality of upper wind channels blowing to the film tube are arranged on the lower wind lip; the lower air lip is provided with an annular groove, the annular groove is provided with an opening, an adjusting ring is connected in the annular groove in a sliding manner, the adjusting ring is provided with a through hole, and each upper air channel can be communicated with the annular main air channel through the through hole and the opening;

2. A method of blow molding plastic film according to claim 1, wherein: the rotary table is sleeved on the adjusting ring through threads, the rotary table is rotatably connected to the lower air lip, and the rotary table can drive the adjusting ring to move up and down.

3. A method of blow molding a plastic film according to claim 2, wherein: step 4, when the thin film tube is removed electrostatically, the method also comprises step A of supporting the thin film tube, wherein the supporting block is required to be used;

the supporting shoe is piled up by a plurality of backup pad and is formed, has seted up a plurality of air grooves in the backup pad, forms the arborescent groove between a plurality of air grooves, and the air groove of adjacent backup pad forms the air flue, and the one end equipartition of air flue is on the periphery of supporting shoe, and the air flue end on the periphery of supporting shoe is the branch end of arborescent groove, is equipped with the negative pressure machine in the frame, and the air flue communicates with the negative pressure machine, supports the film pipe through the air flue of taking the negative pressure.

4. A method of blow molding plastic film according to claim 3, wherein: and the supporting block in the step A is rotatably connected to the frame.

5. A method of blow molding plastic film according to claim 4, wherein: the inclined frame in the step 5 is fixedly connected to a chassis which is arranged on the frame in a rotating way.

6. A method of blow molding plastic film according to claim 5, wherein: the supporting block and the chassis rotate synchronously, and the rack is provided with a driving unit for driving the chassis and the supporting block to rotate synchronously.

7. A method of blow molding plastic film according to claim 1, wherein: and step B, thin film tube thickness detection is further arranged between the step 6 and the step 7, and the step B detects the wall thickness of the thin film tube through a thin film tube thickness detection device.

8. A method of blow molding plastic film according to claim 7, wherein: and step C, cutting the thin film tube, wherein the step C is used for cutting the waste material of the thin film tube and the specific width of the thin film by a thin film tube cutting device.

9. A method of blow molding plastic film according to claim 8, wherein: and D, recovering waste materials of the film tube between the step C and the step 7, wherein the waste materials of the film tube are recovered by a film tube waste material recovery device in the step D.