CN112757537A

CN112757537A - PET bottle blank mould

Info

Publication number: CN112757537A
Application number: CN202110134445.9A
Authority: CN
Inventors: 魏忠坤
Original assignee: Hangzhou Daili Cultural And Creative Co ltd
Current assignee: Hangzhou Daili Cultural And Creative Co ltd
Priority date: 2021-02-01
Filing date: 2021-02-01
Publication date: 2021-05-07

Abstract

The invention discloses a PET bottle blank mold, which comprises a fixed mold seat, a cavity fixing plate, a cavity insert, a cavity, a sprue bush, a sprue, a mounting hole, a guide sleeve, a guide pillar, a core fixing plate, a core insert, a cross runner, an inner runner, a flange forming cavity, a thread forming cavity, a primary liftout mechanism, a secondary liftout mechanism, a tertiary liftout mechanism arranged on the secondary liftout mechanism, a supporting block arranged at the lower part of the core fixing plate and a movable mold plate fixedly connected with the supporting block; the method is characterized in that: the thread forming cavity comprises a thread sleeve opening which is fixedly connected with the thread forming cavity in a rotatable mode and a thread die which is fixedly connected inside the thread sleeve opening. According to the invention, through arranging the thread forming cavity and the multi-stage material ejecting mechanism, a bottle mouth thread with higher quality can be formed at one time during injection molding of a bottle blank, and the bottle mouth thread can be smoothly demoulded, so that the problem that the bottle mouth thread is difficult to be formed simultaneously by a traditional bottle blank is solved.

Description

PET bottle blank mould

Technical Field

The invention belongs to an injection mold, and particularly relates to a PET bottle blank mold.

Background

Polyethylene terephthalate is the most important type of thermoplastic polyester, and is known as polythene terephthalate (PET) or PETP (hereinafter also referred to as PET) in English, and is commonly referred to as polyester resin. It is a polycondensate of terephthalic acid and ethylene glycol, collectively known as thermoplastic polyester, or saturated polyester, with PBT; PET is a milky white or yellowish highly crystalline polymer with a smooth and glossy surface; creep resistance, fatigue resistance, friction resistance and dimensional stability are good, abrasion is small, hardness is high, and the thermoplastic plastic has the maximum toughness; the electric insulation performance is good, the temperature influence is small, but the corona resistance is poor. The paint has the advantages of no toxicity, good weather resistance, good chemical resistance stability, low water absorption, weak acid resistance and organic solvent resistance;

the PET bottle has strong applicability, and is widely applied to the fields of articles for daily use, daily chemical packaging and the like. The product has strong picking property from the processing of the mould to the machine equipment, is easy to enter the door and is difficult to finish; the PET preform is processed again by blow molding into a plastic bottle including bottles for packaging of cosmetics, medicines, health care, beverages, mineral water, reagents, etc., and this bottle-making method is called a two-step method, i.e., a method of forming a preform by injection molding and forming a PET plastic bottle by blow molding again; in the prior art of preparing PET bottle blanks by a mold, threads of a bottle mouth are difficult to form at one time, secondary processing is often needed, and the process is complicated, and the main reason is that the threads are difficult to finish automatic demolding in the mold; in order to complete the forming and demoulding operation of threads, parting surfaces are arranged on the central axis of the threads in some current mainstream moulds, although the threads can be smoothly demoulded by the method, the threads are generally low in quality and serious in flash, and the finishing quality of products is not facilitated.

Disclosure of Invention

The invention provides a PET bottle blank mold which can form bottle mouth threads with high quality and can automatically demold in order to overcome the defects of the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme: a PET bottle blank mold comprises a fixed mold base, a mold cavity fixing plate fixedly connected with the fixed mold base, a mold cavity insert detachably connected with the mold cavity fixing plate, a mold cavity arranged on the mold cavity insert, a sprue bush fixedly connected with the fixed mold base, a sprue arranged on the mold cavity fixing plate, a mounting hole arranged on the mold cavity fixing plate, a guide sleeve slidably connected with the mounting hole, a guide pillar slidably connected with the guide sleeve, a mold core fixing plate fixedly connected with the guide pillar, a mold core insert detachably arranged on the mold core fixing plate, a cross runner arranged on the mold core insert, an inner runner communicated with the cross runner, a flange forming cavity communicated with the inner runner, a thread forming cavity arranged at the lower part of the flange forming cavity, a primary material ejecting mechanism arranged at the lower part of the thread forming cavity, a secondary material ejecting mechanism arranged at the lower part of the primary material ejecting mechanism, a secondary material ejecting mechanism arranged, The three-stage ejection mechanism is arranged on the two-stage ejection mechanism, the supporting block is arranged at the lower part of the core fixing plate, and the movable template is fixedly connected to the supporting block; the thread forming cavity comprises a thread sleeve opening which is fixedly connected with the thread forming cavity in a rotatable mode and a thread die which is fixedly connected inside the thread sleeve opening; installing a mold on an injection molding machine, injecting molten PET plastic into a sprue through a sprue bush by a screw injection molding machine, further entering a horizontal runner and an inner runner, gradually filling a cavity with further molten materials, and then carrying out pressure-maintaining shaping under the pressure of the injection molding machine; the parting surface of the die is arranged at the lower part of the flange, so that the precision of the bottle mouth can be guaranteed to the greatest extent, the thread forming bin and the bottle body forming bin are separated through the flange, the forming of the thread forming bin and the bottle body forming bin cannot interfere with each other, the integral forming precision is high, meanwhile, the parting surface does not pass through a thread forming cavity, the integral forming thread is high in quality, strong in durability and few in defects, the phenomenon of thread slipping is reduced, and the sealing performance after the bottle mouth and a bottle cap are buckled is improved; meanwhile, the independent insert blocks are adopted by the mold core and the mold cavity, so that the mold repair and the insert block replacement can be more conveniently carried out, and the workload of maintenance is reduced.

The primary material ejecting mechanism comprises a plurality of primary material ejecting holes arranged on the threaded sleeve opening, an ejecting pin slidably connected to the ejecting holes, a reset spring sleeved on the ejecting pin, a starting gear fixedly connected to the threaded sleeve opening, unloading notches arranged on two sides of the core fixing plate, a sliding tooth groove arranged on the core fixing plate, a sliding rack slidably connected to the sliding tooth groove, an extrusion sliding plate fixedly connected to the sliding rack, an extrusion inclined plane arranged on the extrusion sliding plate, a material ejecting groove arranged on the inner side of the supporting block, a top plate slidably connected to the material ejecting groove, a top rod fixing plate detachably connected to the top plate, a pressure hole arranged at the lower part of the movable template, a base plate fixedly connected to the top rod fixing plate and a flange arranged on the base plate; after the pressure maintaining is finished, the demoulding operation is started, under the action of the pulling force of the injection molding machine, the movable mold plate drives the mold core fixing plate to start to be away from the mold core fixing plate at the parting surface until a sufficient distance is reached between the mold core fixing plate and the mold cavity fixing plate, the injection molding machine starts to start the ejecting operation, the cooled PET bottle blank is wrapped on the mold core due to the effects of thermal expansion and cold contraction, the ejecting mechanism applies pressure to the bottom of the top plate through a pressure hole, the top plate drives the ejector rod fixing plate to slide along the ejecting groove, the base plate moves upwards, the flanges start to extrude the inclined plane to drive the extrusion sliding plate to slide along the sliding tooth groove, further, under the meshing action, the starting gear starts to rotate to drive the threaded sleeve opening to rotate, and as a plurality of bottle blanks are connected together by residual materials in the flow channel, a single bottle blank cannot rotate, and, the preform has a tendency to move away from the core; through setting up the screw thread running-on, can break away from through the rotation of sliding rack and starting gear with the screw thread mould with the fashioned screw thread of bottle base before the drawing of patterns, make the bottle base possess by the condition under the ejector pin top to rotatory structural feature that has broken away from following the screw thread can not produce the destruction to the intensity and the outward appearance of screw thread, and the bottleneck screw thread after the shaping has higher structural strength and durability, and the screw thread can produce certain pre-thrust to the bottle base, is favorable to the further drawing of patterns of bottle base.

The second-stage material ejecting mechanism comprises a plurality of first-stage discharging holes arranged at the lower part of the thread forming cavity and a first-stage ejector rod detachably connected to the ejector rod fixing plate and slidably connected to the first-stage discharging holes; further, the base plate drives the sliding rack to move to a limit position, the sliding rack stops moving, the starting gear stops rotating, the first-stage ejection hole is overlapped with the first-stage discharge hole, the top plate and the ejector rod fixing plate continue moving, the first-stage ejector rod moves upwards to drive the ejection pin to move upwards, the ejection pin extrudes the flange position of the bottle blank, preliminary ejection is carried out on the bottle blank, the wrapping force of the bottle blank on the mold core is reduced, and further demolding is facilitated; the secondary material ejecting mechanism is carried out after the threads are unscrewed, so that the adhesion of the bottle blank to the mold core can be damaged when the bottle blank is formed, and the bottle blank is more easily separated from the mold core; the screw thread cover mouth has certain limiting action to the one-level ejector pin, and under the condition that the screw thread does not rotate and breaks away from, the position of one-level ejection hole and one-level discharge opening is staggered each other, and the second grade liftout action can't be marchd, from taking the sequence protection, avoids because the unstability of machine arouses the upper and lower activity of one-level ejector pin to cause the bottle base to suffer destruction in forming process, can guarantee the shaping quality of bottle base.

The three-stage ejection mechanism comprises a plurality of second-stage discharge holes arranged below the cross gate, a three-stage discharge hole arranged in a middle part of the cross gate, a second-stage ejector rod connected to the second-stage discharge holes in a sliding manner, and a third-stage ejector rod connected to the third-stage discharge holes in a sliding manner, wherein the third-stage ejector rod comprises a base fixedly connected to an ejector rod fixing plate, a first piston fixedly connected to the base, a piston cylinder slidably connected to the first piston, a first air pressure bin arranged on the piston cylinder, a second piston slidably connected to the second air pressure bin, and a sealing plate fixedly connected to the second piston; the diameter of the second air pressure cabin is larger than that of the second air pressure cabin; when the second-level ejection mechanism works, the third-level ejection mechanism starts to work, the second-level ejector rod and the third-level ejector rod move simultaneously, the second-level ejector rod ejects concretions in a cross runner, the third-level ejector rod uniformly ejects the whole bottle blank and runner residues, the base moves upwards, the first piston moves along the first air pressure bin, the air pressure in the first air pressure bin is increased, under the action of air pressure, the second piston moves along the second air pressure chamber, because the diameter of the first air pressure chamber is far larger than that of the second air pressure chamber, the stroke of the second piston is several times of that of the first piston, so that the second piston has enough length to push the formed bottle blank away from the mold core integrally to finish discharging, due to the material ejecting function of the first-stage material ejecting mechanism and the second-stage material ejecting mechanism, the thrust required by the third-stage material ejecting mechanism can be greatly reduced, and the requirement of air pressure pushing is met; two air pressure bins with different diameters can be arranged, so that the short stroke of the first piston can be exchanged to the long stroke of the second piston, and the ejection can be carried out for a long distance in a limited space, thereby reducing the volume of the whole die and having compact structure; multistage liftout mechanism all can start in order, retrieves automatically, and degree of automation is higher.

A plurality of reset holes are formed in the core fixing plate; the ejector rod fixing plate is provided with a reset rod; the reset rod is connected with the reset hole in a sliding manner; reset hole and release link can carry out the during operation at roof and liftout mechanism, provide accurate guide effect, avoid letting the ejector pin bear the yawing force at the liftout in-process, accelerated wear and tear and cause the bending.

The inner pouring gate is arranged on the inner side of the flange forming cavity; preferably, the present mold should be mounted on a horizontal injection molding machine. When moulding plastics like this, the runner position can be in the downside of die cavity, and the melting material can be followed the ingate and got into the die cavity by the intersection, from down and fill up the die cavity, and original air in the die cavity can be followed the die cavity upside and discharged by the die joint like this, avoids causing the gas trapping phenomenon.

In summary, the invention has the following advantages: through having set up screw thread shaping chamber and multistage liftout mechanism, can once only form the higher high-quality bottleneck screw thread of shaping in bottle base injection moulding to drawing of patterns smoothly has solved the problem that traditional bottle base is difficult to simultaneous moulding bottleneck screw thread, and the compact structure of mould, rationally distributed, the shaping quality of bottle base is higher.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a top view of the present invention.

Fig. 3 is a cross-sectional perspective view of fig. 2 taken along a-a.

Fig. 4 is an enlarged view of a portion a in fig. 3.

Fig. 5 is an enlarged view at B in fig. 3.

FIG. 6 is a schematic view of a cavity retainer plate according to the present invention.

FIG. 7 is a schematic view of a core plate according to the present invention.

Fig. 8 is an exploded view of the present invention.

Fig. 9 is an enlarged view at C in fig. 8.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

As shown in fig. 1-9, a PET bottle blank mold comprises a fixed mold base 1, a cavity 13 fixing plate 11, a cavity 13 insert 12, a cavity 13, a sprue bush 14, a sprue 15, a mounting hole 16, a guide bush 17, a guide post 18, a core fixing plate 19, a core insert 20, a cross runner 21, an inner runner 22, a flange forming cavity 23, a thread forming cavity 3, a primary liftout mechanism 4, a secondary liftout mechanism 5, a tertiary liftout mechanism 6, a support block 7 and a movable mold plate 8; the cavity 13 and the fixing plate 11 are fixedly connected to the fixed die holder 1; the cavity 13 insert 12 is detachably connected to the cavity 13 fixing plate 11; the cavity 13 is arranged on the cavity 13 insert 12; the sprue bush 14 is fixedly connected to the fixed die holder 1; the sprue 15 is arranged in the cavity 13 fixing plate 11; the mounting hole 16 is arranged on the fixing plate 11 of the cavity 13; the guide sleeve 17 is connected to the mounting hole 16 in a sliding manner; the guide post 18 is slidably connected to the guide sleeve 17; the core fixing plate 19 is fixedly connected to the guide post 18; the core insert 20 is detachably mounted to the core fixing plate 19; the cross runners 21 are arranged on the core insert 20; the ingate 22 is communicated with the cross gate 21; the flange forming cavity 23 is communicated with the ingate 22; the thread forming cavity 3 is arranged at the lower part of the flange forming cavity 23; the primary material ejecting mechanism 4 is arranged at the lower part of the thread forming cavity 3; the secondary material ejecting mechanism 5 is arranged at the lower part of the primary material ejecting mechanism 4; the third-stage material ejecting mechanism 6 is arranged at the lower part of the second-stage material ejecting mechanism 5; the supporting block 7 is arranged at the lower part of the core fixing plate 19; the movable mould plate 8 is fixedly connected to the supporting block 7; the thread forming cavity 3 comprises a thread sleeve opening 31 and a thread die 32; the thread sleeve opening 31 is fixedly connected to the thread forming cavity 3 in a rotatable manner; the thread die 32 is fixedly connected to the inside of the thread sleeve opening 31.

The primary material ejecting mechanism 4 comprises a primary material ejecting hole 41, an ejecting pin 42, a return spring 43, a starting gear 44, a discharging notch 45, a sliding tooth groove 46, a sliding rack 47, an extruding sliding plate 48, an extruding inclined plane 49, an ejecting groove 410, a top plate 411, an ejecting rod fixing plate 412, a pressure hole 413, a base plate 414 and a flange 415; three primary material jacking holes 41 are formed in the threaded sleeve opening 31; the ejection pin 42 is slidably connected to the ejection hole; the return spring 43 is sleeved on the ejector pin 42; the starting gear 44 is fixedly connected to the threaded sleeve opening 31; the discharging gaps 45 are arranged on two sides of the core fixing plate 19; the sliding tooth grooves 46 are arranged on the core fixing plate 19; the sliding rack 47 is slidably connected to the sliding toothed groove 46; the extrusion sliding plate 48 is fixedly connected to the sliding rack 47; the extrusion inclined surface 49 is arranged on the extrusion sliding plate 48; the material ejecting groove 410 is arranged on the inner side of the supporting block 7; the top plate 411 is slidably connected to the material ejecting groove 410; the top rod fixing plate 412 is detachably connected to the top plate 411; the pressure hole 413 is arranged at the lower part of the movable template 8; the base plate 414 is fixedly connected to the top rod fixing plate 412; the rib 415 is disposed on the substrate 414.

The secondary material ejecting mechanism 5 comprises a primary discharging hole 51 and a primary ejector rod 52; three primary discharge holes 51 are arranged at the lower part of the thread forming cavity 3; the primary lift pins 52 are detachably connected to the pin fixing plate 412 and slidably connected to the primary discharge holes 51.

The three-stage material ejecting mechanism 6 comprises a second-stage discharging hole 61, a third-stage discharging hole 62, a second-stage ejector rod 63, a third-stage ejector rod 64, a base 65, a first piston 66, a piston cylinder 67, a first air pressure bin 68, a second air pressure bin 69, a second piston 610 and a sealing plate 611; the two secondary discharge holes 61 are arranged below the horizontal pouring gate 21; the third-stage discharge hole 62 is formed in the middle of the cross runner 21; the secondary ejector rod 63 is connected with the secondary discharge hole 61 in a sliding manner; the third-stage ejector rods 64 are slidably connected to the third-stage discharge holes 62; the base 65 is fixedly connected to the mandril fixing plate 412; the first piston 66 is fixedly connected to the base 65; the piston cylinder 67 is slidably connected to the first piston 66; the first air pressure bin 68 is arranged on the piston cylinder 67; the second air pressure chamber 69 is arranged on the piston cylinder 67; the second piston 610 is slidably connected to the second pneumatic chamber 69; the sealing plate 611 is fixedly connected to the second piston 610; the second pneumatic chamber 69 has a larger diameter than the second pneumatic chamber 69.

A plurality of reset holes 191 are formed in the core fixing plate 19; the ejector rod fixing plate 412 is provided with a reset rod 192; the reset rod 192 is slidably coupled to the reset hole 191.

The ingate 22 is arranged inside the molding cavity 23 of the rib 415. .

The specific working process is as follows:

installing the mold on an injection molding machine, injecting molten PET plastic into the sprue 15 through the sprue bush 14 by the screw injection molding machine, further entering the horizontal runner 21 and the inner runner 22, gradually filling the cavity 13 with further molten materials, and then carrying out pressure-maintaining shaping under the pressure of the injection molding machine; the parting surface of the die is arranged at the lower part of the flange, so that the precision of the bottle mouth can be guaranteed to the greatest extent, the thread forming bin and the bottle body forming bin are separated through the flange, the forming of the thread forming bin and the bottle body forming bin cannot interfere with each other, the integral forming precision is high, meanwhile, the parting surface does not pass through the thread forming cavity 3, the integral forming thread is high in quality, strong in durability and few in defects, the phenomenon of thread slipping is reduced, and the sealing performance after the bottle mouth and the bottle cap are buckled is improved; meanwhile, the independent insert adopted by the mold core and the mold cavity 13 can be used for more conveniently repairing the mold and replacing the insert, thereby reducing the workload of maintenance and repair

After the pressure maintaining is finished, the demolding operation is started, under the action of the pulling force of the injection molding machine, the movable mold plate 8 drives the core fixing plate 19 to start to be away from the core fixing plate 19 at the parting surface until the sufficient distance between the core fixing plate 19 and the cavity 13 fixing plate 11 is reached, the injection molding machine starts to start the material ejecting operation, the cooled PET bottle blank is wrapped on the core due to the effects of thermal expansion and cold contraction, the material ejecting mechanism applies pressure to the bottom of the ejector plate 411 through the pressure hole 413, the ejector plate 411 drives the ejector rod fixing plate 412 to slide along the ejector groove 410, the base plate 414 moves upwards, the blocking edge 415 starts to extrude the inclined plane 49 to drive the extrusion sliding plate 48 to slide along the sliding tooth groove 46, further, under the meshing action, the starting gear 44 starts to rotate to drive the thread sleeve opening 31 to rotate, and as a plurality of bottle blanks are connected together by residual materials in the flow, the thread on the preform progressively rotates away from the thread die 32, the preform having a tendency to move away from the core; through setting up screw thread running-on 31, can break away from with screw thread mould 32 through the rotation of sliding rack 47 with starting gear 44 with the fashioned screw thread of bottle base before the drawing of patterns, make the bottle base possess the condition under being pushed up by the ejector pin, and rotatory structural feature who has broken away from following the screw thread, can not produce destruction to the intensity and the outward appearance of screw thread, the bottleneck screw thread after the shaping has higher structural strength and durability, the screw thread can produce certain thrust to the bottle base, be favorable to the further drawing of patterns of bottle base

Further, the base plate 414 drives the sliding rack 47 to move to a limit position, the movement is stopped, the starting gear 44 stops rotating, the first-stage ejection hole 41 coincides with the first-stage discharge hole 51, the top plate 411 and the ejector rod fixing plate 412 continue to move, the first-stage ejector rod 52 moves upwards to drive the ejection pin 42 to move upwards, the ejection pin 42 extrudes the flange 415 of the bottle blank, the bottle blank is preliminarily ejected, the wrapping force of the bottle blank on the mold core is reduced, and further demolding is facilitated;

when the second-stage ejection mechanism 5 works, the third-stage ejection mechanism 6 starts to work, the second-stage ejector rods 63 and the third-stage ejector rods 64 move simultaneously, the second-stage ejector rods 63 eject out concretions in the cross runners 21, the third-stage ejector rods 64 eject out the whole bottle blanks and runner residues uniformly, the base 65 moves upwards, the first piston 66 moves along the first air pressure bin 68, the air pressure in the first air pressure bin 68 is increased, the second piston 610 moves along the second air pressure bin 69 under the action of the air pressure, the diameter of the first air pressure bin 68 is far larger than that of the second air pressure bin 69, the stroke of the second piston 610 is multiple times of that of the first piston 66, so that the second piston 610 has enough length to push the whole formed bottle blanks away from the mold core, and the unloading is completed, and due to the ejection effects of the first-stage ejection mechanism 4 and the second-stage ejection mechanism 5, the thrust required by the third-stage ejection mechanism 6 is greatly reduced, meet the requirement of air pressure pushing

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A PET bottle blank mold comprises a fixed mold base (1), a cavity (13) fixing plate (11) fixedly connected to the fixed mold base (1), a cavity insert (12) detachably connected to the cavity (13) fixing plate (11), a cavity (13) arranged on the cavity insert (12), a sprue bush (14) fixedly connected to the fixed mold base (1), a sprue (15) arranged on the cavity (13) fixing plate (11), a mounting hole (16) arranged on the cavity (13) fixing plate (11), a guide sleeve (17) slidably connected to the mounting hole (16), a guide pillar (18) slidably connected to the guide sleeve (17), a core fixing plate (19) fixedly connected to the guide pillar (18), a core insert (20) detachably mounted on the core fixing plate (19), and a cross runner (21) arranged on the core insert (20), The device comprises an ingate (22) communicated with a cross runner (21), a flange forming cavity (23) communicated with the ingate (22), a thread forming cavity (3) arranged at the lower part of the flange forming cavity (23), a primary ejection mechanism (4) arranged at the lower part of the thread forming cavity (3), a secondary ejection mechanism (5) arranged at the lower part of the primary ejection mechanism (4), a tertiary ejection mechanism (6) arranged at the secondary ejection mechanism (5), a supporting block (7) arranged at the lower part of a core fixing plate (19) and a movable template (8) fixedly connected with the supporting block (7); the method is characterized in that: the thread forming cavity (3) comprises a thread sleeve opening (31) which is fixedly connected with the thread forming cavity (3) in a rotatable mode and a thread die (32) which is fixedly connected with the inner portion of the thread sleeve opening (31).

2. The PET bottle preform mold of claim 1, wherein: the one-level ejection mechanism (4) comprises a plurality of one-level ejection holes (41) arranged in the threaded sleeve opening (31), an ejection pin (42) slidably connected to the one-level ejection holes (41), a return spring (43) sleeved on the ejection pin (42), a starting gear (44) fixedly connected to the threaded sleeve opening (31), unloading notches (45) arranged at two sides of the core fixing plate (19), a sliding tooth groove (46) arranged in the core fixing plate (19), a sliding rack (47) slidably connected to the sliding tooth groove (46), an extrusion sliding plate (48) fixedly connected to the sliding rack (47), an extrusion inclined surface (49) arranged on the extrusion sliding plate (48), an ejection groove (410) arranged at the inner side of the supporting block (7), a top plate (411) slidably connected to the ejection groove (410), and an ejection rod fixing plate (412) detachably connected to the top plate (411), The pressure hole (413) is arranged at the lower part of the movable template (8), the base plate (414) is fixedly connected with the ejector rod fixing plate (412), and the flange (415) is arranged on the base plate (414).

3. The PET bottle preform mold of claim 2, wherein: the secondary material ejecting mechanism (5) comprises a plurality of primary discharging holes (51) arranged at the lower part of the thread forming cavity (3) and a primary ejector rod (52) detachably connected to the ejector rod fixing plate (412) and slidably connected to the primary discharging holes (51);

4. the PET bottle preform mold of claim 3, wherein: the three-stage ejection mechanism (6) comprises a plurality of second-stage discharge holes (61) arranged below the cross gate (21), third-stage discharge holes (62) arranged in the middle part of the cross gate (21), second-stage ejector rods (63) connected to the second-stage discharge holes (61) in a sliding manner, and third-stage ejector rods (64) connected to the third-stage discharge holes (62) in a sliding manner, wherein each third-stage ejector rod (64) comprises a base (65) fixedly connected to the ejector rod fixing plate (412) and a first piston (66) fixedly connected to the base (65), a piston cylinder (67) slidably connected to the first piston (66), a first pneumatic chamber (68) provided in the piston cylinder (67), a second pneumatic chamber (69) provided in the piston cylinder (67), a second piston (610) slidably connected to the second pneumatic chamber (69), and a sealing plate (611) fixedly connected to the second piston (610); the diameter of the second pneumatic chamber (69) is larger than that of the second pneumatic chamber (69).

5. The PET bottle preform mold of claim 4, wherein: a plurality of reset holes (191) are formed in the core fixing plate (19); a reset rod (192) is arranged on the top rod fixing plate (412); the reset rod (192) is connected with the reset hole (191) in a sliding mode.

6. The PET bottle preform mold of claim 1, wherein: the inner pouring channel (22) is arranged on the inner side of the flange (415) forming cavity (23).