Automatic forming machine for bio-based environment-friendly bag

Abstract

The invention discloses an automatic forming machine for a bio-based environment-friendly bag. The automatic forming machine comprises a feeding cylinder, a screw extruder, an annular steel die, a herringbone clamping plate, a winding mechanism and an opening binding die. The feeding cylinder discharges materials downwards in a hopper shape; the screw extruder is communicated with the discharging end of the feeding cylinder; the feeding end of the annular steel die communicates with the discharging end of the right-angle machine head, and the forming raw materials are continuously extruded and formed into a tubular bag through the annular steel die. The herringbone clamping plate is arranged above the bubble stabilizing frame; the winding mechanism is arranged on one side of the downstream of the herringbone clamping plate in the conveying direction of the environment-friendly bag; an opening binding die is arranged on the peripheral side of the annular steel die, and tubular bags which are formed by the annular steel die and are not cooled enter the opening binding die and then gradually abut against the top wall of the opening binding die to be gathered and bound; according to the invention, the opening binding die is arranged at the film blowing outlet of the annular steel die so as to bind the opening of the tubular bag subjected to film blowing molding by the annular steel die, and the end part of the tubular bag does not need to be manually bound when the tubular bag is primarily blown out by the annular steel die.

Description

Technical Field

[0001] The invention relates to the technical field of environmentally friendly bag production equipment, and in particular to an automatic forming machine for bio-based environmentally friendly bags. Background Art

[0002] Environmentally friendly plastic bags can be produced by calendering, extrusion, blow molding and other processes. In the process of blown film molding, according to the different extrusion and traction directions, it can be divided into three types: flat blowing, up blowing and down blowing. The up-extrusion and up-blowing method is widely used in the production process of environmentally friendly bags.

[0003] In the prior art, the blow molding process of environmentally friendly bags is carried out by the "upper extrusion and upper blowing method", which is to melt the plastic raw materials through an extruder to extrude the raw materials into a thin tube, and then blow it up with compressed air while it is hot, and then cool it down to get a film product. That is, the process of blowing the tube embryo, cooling, pulling, and winding.

[0004] However, in the existing environmentally friendly bag automatic forming machine, the tube blank is in an open state at the initial stage of extrusion molding, and its port needs to be manually sealed before compressed air can be filled to inflate it to form a certain stable bubble tube state. Summary of the invention

[0005] The purpose of the present invention is to provide an automated forming machine for bio-based environmentally friendly bags to solve the problem that in existing devices, when the initial outlet of the blown film formed tubular bag is tied, the bag mouth is mainly tied manually, which affects its sealing performance and is inconvenient to operate.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] The present invention provides an automatic forming machine for bio-based environmentally friendly bags, comprising: a feeding barrel, which is in a bucket shape and feeds downward, and is used to heat and melt bio-based plastic particles to form forming raw materials for environmentally friendly bags; a screw extruder, which is connected to the discharge end of the feeding barrel, and the screw extruder is used to convey the forming raw materials in a horizontal direction and continuously heat them, and the discharge end of the screw extruder is provided with a right-angle head, and the forming raw materials are upwardly extruded through the right-angle head; an annular steel mold, whose feeding end is connected to the discharge end of the right-angle head, and the forming raw materials are continuously extruded through the annular steel mold to be formed into a tubular bag; a cooling air ring is provided above the annular steel mold to provide circulating air for cooling the tubular bag; a A bubble stabilizing frame is provided for stabilizing the shape of the tubular bag; a herringbone plywood is arranged above the bubble stabilizing frame, the herringbone plywood is used to press the tubular bag into a fitted environmentally friendly bag, and a traction roller is arranged above the herringbone plywood; a winding mechanism is arranged on the downstream side of the herringbone plywood in the conveying direction of the environmentally friendly bag, and is used to wind up the fitted environmentally friendly bag; wherein, a tie-mouth mold is provided on the circumferential side of the annular steel mold, and the tie-mouth mold is a cylindrical coaxial cover with at least one end open and arranged on the annular steel mold; the top wall of the tie-mouth mold is an arc surface, and the tubular bag that has not yet cooled after being formed by the annular steel mold enters the tie-mouth mold and gradually presses against its top wall to gather and tie the mouth; the tie-mouth mold can be moved away from the tubular bag output path area on the annular steel mold.

[0008] Furthermore, a flange is provided on the cuff mold, and a groove is provided on the annular steel mold. The flange is embedded in the groove so that the cuff mold cover is limited to be located on the annular steel mold, and the cuff mold is rotated to twist the end of the tubular bag with the cuff gathered. A rolling groove is sunken at the bottom of the groove, and a roller is embedded in the rolling groove. The annular top surface of the flange protrudes outward to form a limiting ring, and the limiting ring extends in its height direction into the rolling groove to conflict with the roller.

[0009] Furthermore, a rubber pad is provided on the inner top wall of the cuff mold to increase the friction between it and the tubular bag; wherein the rubber pad is disc-shaped and embedded in the inner top wall of the cuff mold, and the annular outer edge of the rubber pad extends out of the inner top wall of the cuff mold for a smooth transition.

[0010] Furthermore, a draw-opening through hole is opened in the middle of the top wall of the draw-opening mold, and the tubular bag passes through the draw-opening through hole to form a draw-opening portion; wherein, the draw-opening portion is sealed by bonding a flexible ring sheet; an adhesive is pre-attached on the edge of the flexible ring sheet to form a bonding surface, and the bonding surface of the flexible ring sheet is covered by tearable oil paper.

[0011] Furthermore, the edge of the mouth of the constriction opening is folded outwards and pressed on the peripheral side of the hole opening of the constriction opening through hole, and the flexible ring sheet is bonded and sealed to the mouth of the constriction opening.

[0012] Furthermore, the edge of the mouth of the constriction portion is folded inwardly and pressed against the flexible ring sheet for bonding and sealing.

[0013] Furthermore, the cuff mold is axially divided into sub-molds that can be moved and opened and closed in the radial direction; wherein the middle part of each sub-mold is slidably connected to the annular steel mold, and a cuff through hole is formed by merging the sub-molds to simultaneously extrude the tubular bag to form a cuff portion.

[0014] Furthermore, an embedded electric heating wire is provided on the wall surface of the draw-mouth mold to maintain the temperature of the tubular bag; wherein the electric heating wire spirals and extends from the port of the draw-mouth mold to below the arc-shaped top of the draw-mouth mold; the arc-shaped top of the draw-mouth mold includes a transparent plate, through which the gathering and draw-mouth state of the tubular bag in the draw-mouth mold can be observed.

[0015] Furthermore, the foam stabilizing frame comprises a square frame, on which parallel foam stabilizing rollers are provided for contacting the tubular bag.

[0016] Furthermore, the herringbone splint includes two obliquely arranged guide roller groups, the angle between the two guide roller groups is 30°, and the guide roller group includes a plurality of parallel guide rollers, and the tubular bag is extruded into an environmentally friendly bag between the guide rollers located at the ends of the guide roller group.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention provides a tie-end mold at the film blowing outlet of the annular steel mold to tie the tubular bag formed by the film blowing of the annular steel mold, so as to facilitate continuous inflation of the tubular bag by compressed air inside the tubular bag and convey it upward until the tubular bag is pulled by a traction roller and pressed into a fitted environmentally friendly bag through a herringbone splint. There is no need to manually tie the end of the tubular bag when the annular steel mold is initially blown out of the tubular bag, so that the compressed air inside can be conveyed upward after being accumulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0020] Figure 1 A schematic structural diagram of an automatic bio-based environmentally friendly bag forming machine provided by the present invention;

[0021] Figure 2 for Figure 1 Schematic diagram of the structure of the middle herringbone splint;

[0022] Figure 3 A schematic diagram of a structure in which a cuff mold cover is arranged on an annular steel mold in an embodiment provided by the present invention;

[0023] Figure 4 for Figure 1 A cross-sectional view of

[0024] Figure 5 for Figure 4 Partial view of middle Ⅰ;

[0025] Figure 6 A cross-sectional view of a cuff mold in an embodiment of the present invention;

[0026] Figure 7 for Figure 4 Partial view of middle II;

[0027] Figure 8 A cross-sectional view of a cuff mold in an embodiment of the present invention;

[0028] Fig. 9 for Figure 8 Partial view of middle III;

[0029] Fig.10 A cross-sectional view of a cuff mold in an embodiment of the present invention;

[0030] Fig.11 for Fig.10 Partial view of middle IV;

[0031] Fig.12 A schematic diagram of the structure of a cuff mold in an embodiment of the present invention;

[0032] Fig.13 for Fig.12 A cross-sectional view of

[0033] Fig.14 A cross-sectional view of a cuff mold in an embodiment provided by the present invention;

[0034] Fig.15 for Figure 1 Schematic diagram of the structure of the mid-stable bubble rack.

[0035] The numbers in the figure represent the following:

[0036] 10. Feeding barrel; 20. Screw extruder; 21. Right-angle head; 30. Annular steel mold; 31. Cooling air ring; 32. Bubble stabilizing frame; 321. Frame; 33. Groove; 331. Rolling groove; 332. Roller; 40. Herringbone splint; 41. Traction roller; 42. Guide roller group; 43. Guide roller; 50. Winding mechanism; 60. Draw-mouth mold; 601. Transparent plate; 61. Flange; 611. Limiting ring; 62. Rubber pad; 63. Draw-mouth through hole; 64. Draw-mouth part; 65. Flexible ring piece; 66. Sub-mold; 67. Electric heating wire; 70. Tubular bag; 71. Environmentally friendly bag. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] like Figure 1 , 3 As shown, the present invention provides an automatic forming machine for bio-based environmentally friendly bags, comprising:

[0039] A feeding cylinder 10, which is in a bucket shape and feeds downwards, and is used to heat and melt bio-based plastic particles to form molding materials for environmentally friendly bags;

[0040] The screw extruder 20 is connected to the discharge end of the feeding barrel 10. The screw extruder 20 is used to convey the molding raw material in the horizontal direction and continuously heat it. The discharge end of the screw extruder 20 is provided with a right-angle head 21, and the molding raw material is extruded upward through the right-angle head 21;

[0041] The feeding end of the annular steel die 30 is connected to the discharging end of the right-angle die head 21, and the molding raw material is continuously extruded through the annular steel die 30 to be formed into a tubular bag 70; a cooling air ring 31 is provided above the annular steel die 30 to provide circulating air for cooling the tubular bag 70; a bubble stabilizing frame 32 is provided above the cooling air ring 31 to stabilize the shape of the tubular bag 70;

[0042] A herringbone splint 40 is disposed above the bubble stabilizing frame 32. The herringbone splint 40 is used to press the tubular bag 70 into a fitted environmentally friendly bag 71. A traction roller 41 is disposed above the herringbone splint 40;

[0043] A reeling mechanism 50, which is disposed on the downstream side of the herringbone splint 40 in the conveying direction of the environmentally friendly bag and is used to reel in the pasted environmentally friendly bag 71;

[0044] Among them, a cuff mold 60 is provided on the circumferential side of the annular steel mold 30, and the cuff mold 60 is a cylindrical coaxial cover with at least one end open and arranged on the annular steel mold 30; the top wall of the cuff mold 60 is an arc surface, and the tubular bag that has not yet cooled after being formed by the annular steel mold 30 enters the cuff mold 60 and gradually presses against its top wall to gather and cuff; the cuff mold 60 can be moved away from the tubular bag output path area on the annular steel mold 30.

[0045] The present invention aims to provide a tie-end mold 60 at the film blowing outlet of the annular steel mold 30 to tie the end of the tubular bag 70 formed by the film blowing of the annular steel mold 30, so as to facilitate the continuous inflation of the tubular bag 70 by compressed air inside the tubular bag 70 and to convey it upward until the tubular bag 70 is pulled by the traction roller 41 through the herringbone splint 40 and pressed into a fitted environmentally friendly bag 71, without the need to manually tie the ends of the tubular bag 70 when the tubular bag 70 is initially blown out of the annular steel mold 30, so that the compressed air inside can be accumulated and conveyed upward.

[0046] Please continue reading Figure 1 The device installation direction shown in the figure, in this embodiment, the "flat extrusion upward blowing method" is used to manufacture the environmentally friendly bag, that is, the discharge direction of the right-angle head 21 is perpendicular to the screw extruder 20, and the extrusion tube ring inside the right-angle head 21 extrude the raw material upward to form a tubular bag 70, which is pulled to a certain distance and then clamped by the herringbone splint 40. A booster air pump is provided inside the annular steel mold 30 so that it can introduce compressed air from the bottom of the tubular bag 70 to blow it into a bubble tube, and the lateral size of the tubular bag 70 is controlled by the inflation amount of the compressed air, and the longitudinal size of the tubular bag 70 is controlled by the traction speed of the traction roller 41. After the bubble tube is cooled and shaped, the environmentally friendly bag 71 can be obtained.

[0047] In the above embodiment, after the mouth of the tubular bag 70 is gathered to the middle thereof along the direction guided by the arc-shaped top wall of the tie-mouth mold 60, although the edges of the mouth of the tubular bag 70 which have not yet cooled can produce a certain adhesion to each other, it is difficult to form a condensation nodule with a better sealing effect at its mouth, which is not conducive to the booster air pump to continuously introduce compressed air from the bottom of the tubular bag 70 into the interior thereof and to make it continue to expand to a stable bubble tube state, making it difficult for the tubular bag 70 to climb upward to the working area of ​​the herringbone splint 40.

[0048] In order to solve the above problems, Figure 4-5 As shown, in a preferred embodiment provided by the present invention based on the above embodiments, a flange 61 is provided on the cuff mold 60, a groove 33 is provided on the annular steel mold 30, and the flange 61 is embedded in the groove 33 so that the cuff mold 60 cover is limited to be located on the annular steel mold 30, and the cuff mold 60 is rotated to make the end of the tubular bag gathered at the cuff be twisted; wherein, a rolling groove 331 is sunken at the bottom of the groove 33, and a roller 332 is embedded in the rolling groove 331; the annular top surface of the flange 61 protrudes outward to form a limiting ring 611, and the limiting ring 611 extends in its height direction to the inside of the rolling groove 331 and contacts the roller 332.

[0049] In this embodiment, by movably setting the tie-mouth mold 60 on the annular steel mold 30, not only can the rotation effect thereof be utilized to form a condensation nodule at the tie-mouth of the tubular bag 70, but also the tie-mouth mold 60 can be easily removed after the tubular bag 70 is tied, without occupying the ejection path of the tubular bag 70. It should be noted that a plurality of rollers 332 are provided in the rolling groove 331, and the rollers 332 support the overall weight of the tie-mouth mold 60 by supporting the limit ring 611, and the rollers 332 can roll arbitrarily along the circumference of the rolling groove 331; when the limit ring 611 contacts the rollers 332, a matching gap is left between the flange 61 and the groove bottom or groove wall of the groove 33, and a matching gap is also left between the bottom end surface of the tie-mouth mold 60 and the annular steel mold 30, so as to ensure that the tie-mouth mold 60 rotates relatively smoothly under the support of the rollers 332.

[0050] In the above embodiment, the inner wall of the cuff mold 60 is generally smooth, so as to facilitate guiding the tubular bag 70 through its arc-shaped inner top wall. However, during the rotation of the cuff mold 60, due to the small friction between it and the tubular bag 70, it is easy to cause difficulty in forming condensation nodules at the mouth of the tubular bag 70, resulting in the inability to seal the mouth of the tubular bag 70, affecting the internal air intake and inflation effect.

[0051] In order to solve the above problems, Figure 6-7 As shown, in a preferred embodiment provided by the present invention based on the above-mentioned embodiment, a rubber pad 62 is provided on the inner top wall of the cuff mold 60 to increase the friction between it and the tubular bag; wherein the rubber pad 62 is disc-shaped and embedded in the inner top wall of the cuff mold 60, and the annular outer edge of the rubber pad 62 extends out of the inner top wall of the cuff mold 60 for a smooth transition.

[0052] In this embodiment, an embedded rubber pad 62 is provided between the inner top wall of the cuff mold 60 and the contact area of ​​the mouth of the tubular bag 70, so that the friction between the two can be increased without affecting the arc-shaped inner top of the cuff mold 60 to guide and gather the mouth of the tubular bag 70. This is beneficial for the friction between the rubber pad 62 and the tubular bag 70 during the rotation of the cuff mold 60, and it is easy to form condensation nodules on the mouth of the tubular bag 70, so that the mouth of the tubular bag 70 is sealed, thereby improving the internal air intake and inflation effect, which is beneficial to the tubular bag 70 climbing upward.

[0053] In order to visualize the drawstring condition of the tubular bag 70, Figure 8-11 As shown, the present invention is based on the above embodiment, a draw-opening through hole 63 is opened in the middle of the top wall of the draw-opening mold 60, and the tubular bag 70 passes through the draw-opening through hole 63 to form a draw-opening portion 64; wherein, the draw-opening portion 64 is sealed by bonding a flexible ring sheet 65; an adhesive is pre-attached on the edge of the flexible ring sheet 65 to form a bonding surface, and the bonding surface of the flexible ring sheet 65 is covered with tearable oil paper.

[0054] Preferably, please continue to see Figure 8-9 In one embodiment provided by the present invention, the edge of the mouth of the constriction portion 64 is folded outward and pressed against the peripheral side of the opening of the constriction through hole 63 , and the flexible ring piece 65 is bonded and sealed to the mouth of the constriction portion 64 .

[0055] In this embodiment, the flexible ring sheet 65 is used to seal the mouth 64 formed by passing the tubular bag 70 through the through hole 63, so that the mouth of the tubular bag 70 is sealed, and the internal air intake and inflation effect is improved, which is conducive to the upward climbing of the tubular bag 70. It should be noted that the flexible ring sheet 65 is made of flexible material, which does not affect the clamping operation of the herringbone splint 40 on the tubular bag 70; the flexible ring sheet 65 is pre-attached with adhesive near the outer ring side, so that the outer edge of the mouth of the tubular bag 70 can be turned outward and bonded to the flexible ring sheet 65 near its outer ring side to form a seal.

[0056] Preferably, please continue to see Figure 10-11 In another embodiment provided by the present invention, the edge of the mouth of the constriction portion 64 is folded inwardly and pressed against the flexible ring sheet 65 for bonding and sealing.

[0057] In this embodiment, by folding the mouth edge of the tie-mouth portion 64 inward and using the flexible ring sheet 65 for bonding and sealing, the problem of the mouth edge of the tie-mouth portion 64 being easily adhered to the mouth edge of the tie-mouth through hole 63 when the mouth edge of the tie-mouth portion 64 is folded outward for bonding can be avoided.

[0058] In order to facilitate the use of the closing mold 60 to close the tubular bag 70 movably on the annular steel mold 30, as shown in FIG. Figure 12-13 As shown, in a preferred embodiment provided by the present invention based on the above-mentioned embodiment, the draw-mouth mold 60 is divided axially into sub-molds 66 which can be moved and opened and closed along its radial direction; wherein, the middle portion of each sub-mold 66 is slidably connected to the annular steel mold 30, and a draw-mouth through hole 63 is formed by merging the sub-molds 66 to simultaneously extrude the tubular bag to form a draw-mouth portion 64.

[0059] In order to solve the problem that the tubular bag 70 is easily cooled during the upward conveying process, thereby affecting the sealing effect of its end, as shown in FIG. Fig.14 As shown, in a preferred embodiment provided by the present invention based on the above-mentioned embodiments, an embedded electric heating wire 67 is provided on the wall surface of the draw-mouth mold 60 to maintain the temperature of the tubular bag; wherein the electric heating wire 67 spirals and extends from the port of the draw-mouth mold 60 to below the arc-shaped top of the draw-mouth mold 60; the arc-shaped top of the draw-mouth mold 60 includes a transparent plate 601, through which the gathered draw-mouth state of the tubular bag in the draw-mouth mold 60 can be observed.

[0060] like Fig.15As shown, in one embodiment provided by the present invention, in order to enable the tubular bag 70 to maintain its straight cylindrical shape during the upward climbing process, the bubble stabilizing rack 32 preferably includes a square frame 321, and the frame 321 is provided with parallel bubble stabilizing rollers 322 for contacting the tubular bag.

[0061] like Figure 2 As shown, in one embodiment provided by the present invention, in order to extrude the tubular bag 70 into an environmentally friendly bag 71, the herringbone splint 40 includes two obliquely arranged guide roller groups 42, the angle between the two guide roller groups 42 is 30°, and the guide roller group 42 includes a plurality of parallel guide rollers 43, and the tubular bag 70 is extruded into the environmentally friendly bag 71 between the guide rollers 43 located at the ends of the guide roller group 42.

[0062] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. An automatic forming machine for bio-based environmentally friendly bags, characterized in that: include: A feeding cylinder (10) which is in a bucket shape and feeds materials downwards, and the feeding cylinder (10) is used to heat and melt bio-based plastic particles to form molding materials for environmentally friendly bags; A screw extruder (20) is connected to the discharge end of the feeding barrel (10), and the screw extruder (20) is used to convey the molding raw material in the horizontal direction and continuously heat it. The discharge end of the screw extruder (20) is provided with a right-angle head (21), and the molding raw material is extruded upward through the right-angle head (21); The feeding end of the annular steel mold (30) is connected to the discharging end of the right-angle die head (21), and the molding raw material is continuously extruded through the annular steel mold (30) to be molded into a tubular bag (70); a cooling air ring (31) is provided above the annular steel mold (30) to provide circulating air for cooling the tubular bag (70); a bubble stabilizing frame (32) is provided above the cooling air ring (31) to stabilize the shape of the tubular bag (70); A herringbone splint (40) is disposed above the bubble stabilizing frame (32), the herringbone splint (40) is used to press the tubular bag (70) into a fitted environmentally friendly bag (71), and a traction roller (41) is disposed above the herringbone splint (40); A rolling mechanism (50) is arranged on the downstream side of the herringbone splint (40) in the conveying direction of the environmentally friendly bag and is used to roll up the bonded environmentally friendly bag (71); Wherein, a constriction mold (60) is provided on the circumferential side of the annular steel mold (30), and the constriction mold (60) is a cylindrical body with at least one end open and coaxially covered on the annular steel mold (30); The top wall of the cuff mold (60) is an arc surface, and the tubular bag that has not yet cooled down after being formed by the annular steel mold (30) enters the cuff mold (60) and gradually abuts against the top wall thereof to gather and cuff; The closing die (60) can be moved away from the tubular bag output path area on the annular steel die (30).

2. The automatic forming machine for bio-based environmentally friendly bags according to claim 1, characterized in that: The tie-mouth mold (60) is provided with a flange (61), and the annular steel mold (30) is provided with a groove (33). The flange (61) is embedded in the groove (33) so that the tie-mouth mold (60) is limitedly located on the annular steel mold (30). By rotating the tie-mouth mold (60), the end of the tubular bag with the tie-mouth gathered can be twisted; The groove bottom of the groove (33) is sunken to form a rolling groove (331), and a roller (332) is embedded inside the rolling groove (331); The annular top surface of the flange (61) protrudes outward to form a limiting ring (611), and the limiting ring (611) extends in its height direction into the rolling groove (331) to abut against the roller (332).

3. The automatic forming machine for bio-based environmentally friendly bags according to claim 2, characterized in that: A rubber pad (62) is provided on the inner top wall of the tie-end mold (60) to increase the friction between it and the tubular bag; The rubber pad (62) is in the shape of a disc and is embedded in the inner top wall of the cuff mold (60), and the annular outer edge of the rubber pad (62) extends out of the inner top wall of the cuff mold (60) in a smooth transition.

4. The automatic forming machine for bio-based environmentally friendly bags according to claim 1, characterized in that: A draw-opening through hole (63) is provided in the middle of the top wall of the draw-opening mold (60), and the tubular bag passes through the draw-opening through hole (63) to form a draw-opening portion (64); The constriction opening (64) is tightly fitted by bonding a flexible ring sheet (65); An adhesive is pre-attached on the edge of the flexible ring sheet (65) to form an adhesive surface, and the adhesive surface of the flexible ring sheet (65) is covered by tearable oil paper.

5. The automatic forming machine for bio-based environmentally friendly bags according to claim 4, characterized in that: The edge of the mouth of the constriction portion (64) is folded outward and pressed against the peripheral side of the hole of the constriction through hole (63), and the flexible ring sheet (65) is bonded and sealed to the mouth of the constriction portion (64).

6. The automatic forming machine for bio-based environmentally friendly bags according to claim 4, characterized in that: The edge of the mouth of the constriction portion (64) is folded inwards and pressed against the flexible ring sheet (65) for bonding and sealing.

7. An automatic forming machine for bio-based environmentally friendly bags according to any one of claims 4 to 6, characterized in that: The cuff mold (60) is divided into split molds (66) along the axial direction and can be moved and opened and closed along the radial direction; The middle part of each of the sub-molds (66) is slidably connected to the annular steel mold (30), and the draw-off through hole (63) is formed by merging the sub-molds (66) to simultaneously squeeze the tubular bag to form the draw-off portion (64).

8. The automatic forming machine for bio-based environmentally friendly bags according to claim 7, characterized in that: An embedded electric heating wire (67) is provided on the wall surface of the tie-end mold (60) to maintain the temperature of the tubular bag; Wherein, the electric heating wire (67) spirally extends from the port of the cuff mold (60) to below the arc-shaped top of the cuff mold (60); The arc-shaped top of the cuff mold (60) includes a transparent plate (601), through which the gathered cuff state of the tubular bag in the cuff mold (60) can be observed.

9. The automatic forming machine for bio-based environmentally friendly bags according to claim 8, characterized in that: The bubble stabilizing frame (32) comprises a square frame (321), and the frame (321) is provided with parallel bubble stabilizing rollers (322) for contacting the tubular bag.

10. The automatic forming machine for bio-based environmentally friendly bags according to claim 9, characterized in that: The herringbone splint (40) comprises two guide roller groups (42) arranged obliquely, the angle between the two guide roller groups (42) is 30 degrees, the guide roller group (42) comprises a plurality of parallel guide rollers (43), and the tubular bag (70) is extruded and formed into an environmentally friendly bag (71) between the guide rollers (43) located at the ends of the guide roller group (42).

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