Lightweight plastic bottle production device

Abstract

The invention provides a light-weight plastic bottle production device, and relates to the field of plastic bottle blow molding. The light-weight plastic bottle production device comprises a fixing unit for fixing a bottle blank, a mold for wrapping the bottle blank and a top core penetrating through the fixing unit and extending into the bottle blank, and the mold comprises an upper mold with the top end symmetrically opened towards the two sides and a lower mold with the bottom end moving upwards to be connected with the closed upper mold in a clamped mode. According to the light-weight plastic bottle production device, a bottle blank is placed in the mold, the interior of the bottle blank is inflated in the downward moving process of the ejector core, air in the mold is exhausted in cooperation with the exhaust pipe, and therefore the light-weight plastic bottle production device can be used for producing the light-weight plastic bottle, and the production efficiency of the light-weight plastic bottle is improved. And therefore, the bottle blanks can be slowly expanded outwards in the downward stretching process, the stress on the bottle blanks can be more uniform, and thinner plastic bottles can be produced.

Description

Technical Field

[0001] The invention relates to the field of plastic bottle blow molding, in particular to a lightweight plastic bottle production device. Background Art

[0002] Stretch blow molding is an important plastic molding process. After the thermoplastic plastic is made into a preform, the preform is heated to a suitable stretching temperature and stretched longitudinally by mechanical force. At the same time or later, it is blown by compressed air to achieve transverse stretching, so that the plastic macromolecular chains are oriented in two directions, thereby improving the physical and mechanical properties of the product.

[0003] The existing patent (CN215921234U) is an integrally injection-molded preform, which includes a bottle mouth, a bottleneck, a preform body and a preform bottom connected in sequence. The preform bottom is set as an upper bottom and a lower bottom connected, and the bottom end of the lower bottom is lower than the convergence point formed by the extension line of the upper bottom generatrix curve segment I, so that the preform bottom forms a downwardly protruding lower bottom on the basis of the upper bottom molding. The lower bottom serves as a pre-stretching structure of the preform bottom, so that the preform bottom is fully expanded during the stretch blow molding process, avoiding serious material accumulation at the bottle bottom, and more material is distributed to the rest of the bottom of the preform. Therefore, when designing the preform, the wall thickness of the preform bottom can be designed to be thinner to achieve the purpose of lightweight. This technical solution optimizes the structure of the bottle body preform, making the preform more suitable for stretch blow molding. However, during the stretch blow molding process, the top core only deforms vertically during the downward movement of the top core. In order to prevent the preform from breaking, the thickness of the preform needs to be designed to be thicker. In order to reduce the thickness of the preform and produce thinner plastic bottles, a device that can make the preform force uniform during the stretch blow molding process is required. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a lightweight plastic bottle production device, which solves the problem of uneven force on the bottle blank during the stretch blow molding process mentioned in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a lightweight plastic bottle production device, comprising a fixing unit for fixing a preform, a mold for wrapping the preform, and a top core that penetrates the fixing unit and extends into the interior of the preform, the mold comprising an upper mold with a top end symmetrically opened to both sides, and a lower mold with a bottom end that moves upward and is clamped with the closed upper mold, a boss for molding is arranged in the middle of the lower mold, the boss is divided into an upper moving part and a fixed part at the bottom, an exhaust pipe with a through hole on the surface is slidably connected to the middle of the lower mold, the top of the exhaust pipe is fixedly connected to the upper moving part, a compression sealing sleeve is sleeved on the outer surface of the top core, the compression sealing sleeve is connected to the fixing unit to form a seal, a pressure plate is fixedly installed on one end of the surface of the top core located outside the compression sealing sleeve, a sealing plug is fixedly installed on one end of the top core located inside the compression sealing sleeve, the sealing plug is inserted into the interior of the fixing unit, an exhaust hole for exhaust is arranged on the outer surface of the top core located below the sealing plug, and a pressure plate with a smooth surface that fits the upper moving part is fixedly installed on the bottom end of the top core.

[0006] Preferably, a plug-in ring groove is provided at the bottom edge of the upper mold, and a plug-in ring block is fixedly installed at the top of the lower mold. When the plug-in ring block and the plug-in ring groove are closed, the lower mold, the upper mold and the fixing unit form a closed cavity.

[0007] Preferably, the fixing unit comprises a sliding die with two sides pressed toward each other to form a threaded opening, and a fixing die located in the threaded opening, and a moving unit for controlling the movement of the sliding die is fixedly mounted on the outer surface of the fixing die.

[0008] Preferably, the surface of the lower mold is connected to and penetrated by an extension pipe, the exhaust pipe is slidably connected to the inside of the extension pipe, the bottom end of the exhaust pipe is connected to and penetrated by a grille portion, a push rod is fixedly installed at the bottom end of the grille portion, the push rod penetrates the extension pipe and extends to the outside of the extension pipe, and the bottom end of the side wall of the extension pipe is connected to and penetrated by an exhaust port.

[0009] Preferably, a sealing ring is embedded on the top of the outer surface of the exhaust pipe, and the sealing ring is located above the through hole portion of the exhaust pipe.

[0010] Preferably, the air inlet end of the top core is connected to and penetrated by a three-inlet and one-outlet solenoid valve, which controls one of the three inlets to be connected to the outlet, one of the inlets is connected to and penetrated by a controlled exhaust valve, another inlet is connected to the hot air pipe, and the remaining inlet is connected to the cold air pipe.

[0011] Preferably, the bottom and top ends of the compression sealing sleeve are both hard parts, and the middle connection is a bendable and retractable soft part. A magnetic ring is fixedly installed on the bottom end of the compression sealing sleeve, and a plug-in groove adapted to the magnetic ring is opened on the top of the fixed mold, and a magnetic plate that attracts the magnetic ring is embedded inside the plug-in groove.

[0012] Preferably, the exhaust holes of the top core are divided into two groups, the number of the exhaust holes in the top group is greater than the number of the exhaust holes in the bottom group, and the diameter of the exhaust holes in the bottom group is greater than the diameter of the exhaust holes in the top group.

[0013] Preferably, the distance between the sealing plug on the outer surface of the top core and the pressure plate is equal to the length of the compression sealing sleeve after compression, the diameter of the pressure plate is larger than the diameter of the compression sealing sleeve, and the surfaces of the pressure plate, the upper mold and the lower mold away from each other are all provided with protrusions connecting the telescopic device.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The lightweight plastic bottle production device places the preform in the mold, inflates the inside of the preform while the top core moves downward, and exhausts the air in the mold with the help of an exhaust pipe, so that the preform can slowly expand outwards during the downward stretching process, so that the force on the preform is more uniform, thereby producing thinner plastic bottles.

[0015] 2. The lightweight plastic bottle production device, the fixed unit includes a sliding mold with two sides extruded toward each other to form a threaded opening, and a fixed mold located in the threaded opening. The outer surface of the fixed mold is fixedly installed with a moving unit for controlling the movement of the sliding mold. This arrangement makes it easy to fix and transport the bottle embryo.

[0016] 3. In the lightweight plastic bottle production device, the surface of the lower mold is connected to and penetrated by an extension pipe, the exhaust pipe is slidably connected to the inside of the extension pipe, the bottom end of the exhaust pipe is connected to and penetrated by a grille part, the bottom end of the grille part is fixedly installed with a push rod, the exhaust pipe can be moved relative to the lower mold by moving the push rod up and down, so that when the lower mold and the upper mold are closed, the exhaust pipe can be inserted into the interior of the upper mold for exhaust, the push rod penetrates the extension pipe and extends to the outside of the extension pipe, the bottom end of the side wall of the extension pipe is connected to and penetrated by an exhaust port, the exhaust port is used to connect to an existing vacuum pumping device, and such an arrangement can facilitate the control of the up and down movement of the exhaust pipe.

[0017] 4. In the lightweight plastic bottle production device, the bottom and top ends of the compression sealing sleeve are both hard parts, and the middle connection is a bendable and retractable soft part. A magnetic ring is fixedly installed on the bottom end of the compression sealing sleeve, and a plug-in groove adapted to the magnetic ring is opened on the top of the plug-in ring block. The inside of the plug-in groove is inlaid with a magnetic plate that attracts the magnetic ring. Through such an arrangement, the compression sealing sleeve and the fixed mold can form a sealed space, thereby ensuring that there will be no leakage when the top core is supplied with air before the sealing plug is plugged into the fixed mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structural connection of the present invention; Figure 2 It is a half-section schematic diagram of the present invention; Figure 3 This is a schematic diagram of mold connection of the present invention; Figure 4 This is a schematic diagram of the connection of the lower mold of the present invention; Figure 5 This is a schematic diagram of the exhaust pipe connection of the present invention; Figure 6 This is a schematic diagram of the upper mold of the present invention; Figure 7 This is a half-section connection schematic diagram of the fixing unit of the present invention; Figure 8 It is a half-section schematic diagram of the compression sealing sleeve of the present invention; Fig. 9 This is a schematic diagram of the top core connection of the present invention; Fig.10 It is a schematic diagram of the connection of the solenoid valve of the present invention.

[0019] In the figure: 1, fixed unit; 101, sliding mold; 102, fixed mold; 103, moving unit; 2, mold; 3, top core; 201, upper mold; 202, lower mold; 203, boss; 204, upper moving part; 205, fixed part; 206, exhaust pipe; 207, plug-in ring groove; 208, plug-in ring block; 209, extension pipe; 210, grille part; 211, push rod; 212, sealing ring; 213, solenoid valve; 214, control exhaust valve; 215, magnetic ring; 216, plug-in groove; 217, magnetic plate; 218, exhaust port; 301, compression sealing sleeve; 302, pressure plate; 303, sealing plug; 304, exhaust hole; 305, pressure plate. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0022] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0024] like Figure 1-10 As shown, a lightweight plastic bottle production device includes a fixing unit 1 for fixing a preform, a mold 2 for wrapping the preform, and a top core 3 that penetrates the fixing unit 1 and extends to the inside of the preform, the mold 2 includes an upper mold 201 with a top end symmetrically opened to both sides, and a lower mold 202 that moves upward at the bottom and is clamped with the closed upper mold 201, a boss 203 for molding is arranged in the middle of the lower mold 202, the boss 203 is divided into an upper moving part 204 and a fixed part 205 at the bottom, an exhaust pipe 206 with a through hole on the surface is slidably connected to the middle of the lower mold 202, the top of the exhaust pipe 206 is fixedly connected to the upper moving part 204, a compression sealing sleeve 301 is sleeved on the outer surface of the top core 3, and the compression sealing sleeve 301 is connected to the fixing unit 1 to form a seal, and the top core 3 is provided with a compression sealing sleeve 301. A pressure plate 302 is fixedly installed on one end of the surface of the core 3 located outside the compression sealing sleeve 301, and a sealing plug 303 is fixedly installed on one end of the top core 3 located inside the compression sealing sleeve 301. The sealing plug 303 is inserted into the interior of the fixing unit 1, and an exhaust hole 304 is provided on the outer surface of the top core 3 located below the sealing plug 303 for exhaust. A pressure plate 305 with a smooth surface that fits the upper moving part 204 is fixedly installed on the bottom end of the top core 3. By placing the preform in the mold 2, the inside of the preform is inflated while the top core 3 moves downward, and the air in the mold 2 is discharged in conjunction with the exhaust pipe 206, the preform can slowly expand outward during the downward stretching process, so that the force on the preform is more uniform, thereby producing thinner plastic bottles.

[0025] A plug-in ring groove 207 is provided at the bottom edge of the upper mold 201, and a plug-in ring block 208 is fixedly installed at the top of the lower mold 202. When the plug-in ring block 208 and the plug-in ring groove 207 are closed, the lower mold 202, the upper mold 201 and the fixed unit 1 form a closed cavity. Through such an arrangement, the mold 2 can form a complete cavity during the splicing process to avoid a more obvious parting line during forming.

[0026] The fixing unit 1 includes a sliding die 101 with two sides pressed toward each other to form a threaded opening, and a fixing die 102 located in the threaded opening. A moving unit 103 for controlling the movement of the sliding die 101 is fixedly installed on the outer surface of the fixing die 102. This arrangement facilitates the fixing and transportation of the preform.

[0027] The surface of the lower mold 202 is connected to and penetrated by an extension tube 209, and the exhaust pipe 206 is slidably connected to the inside of the extension tube 209. The bottom end of the exhaust pipe 206 is connected to and penetrated by a grille portion 210, and a push rod 211 is fixedly installed at the bottom end of the grille portion 210. The exhaust pipe 206 can be moved relative to the lower mold 202 by moving the push rod 211 up and down, so that when the lower mold 202 and the upper mold 201 are closed, the exhaust pipe 206 can be inserted into the interior of the upper mold 201 for exhaust. The push rod 211 penetrates the extension tube 209 and extends to the outside of the extension tube 209. The bottom end of the side wall of the extension tube 209 is connected to and penetrated by an exhaust port 218, and the exhaust port 218 is used to connect to an existing vacuum extraction device. Through such an arrangement, it is convenient to control the up and down movement of the exhaust pipe 206.

[0028] A sealing ring 212 is embedded at the top of the outer surface of the exhaust pipe 206 , and the sealing ring 212 is located above the through hole portion of the exhaust pipe 206 . This arrangement ensures that no leakage occurs at the connection between the exhaust pipe 206 and the lower mold 202 during the blow molding process.

[0029] The air inlet end of the top core 3 is connected to and penetrated by a solenoid valve 213 with three inlets and one outlet. The solenoid valve 213 controls three inlets to be connected to one of the outlets. One of the inlets is connected to and penetrated by a controlled exhaust valve 214, another inlet is connected to a hot air pipe, and the remaining inlet is connected to a cold air pipe. When the bottle blank is blown to slowly expand around, the hot air supplied through the hot air pipe can soften the bottle blank and facilitate deformation. When the bottle blank is expanded as a whole and contacts the mold 2 for shaping, air is supplied through the cold air pipe so that the bottle blank can be quickly shaped. After shaping is completed and the mold is separated, the controlled exhaust valve 214 can be opened to achieve exhaust.

[0030] The bottom and top of the compression sealing sleeve 301 are both hard parts, and the middle connection is a bendable and retractable soft part. A magnetic ring 215 is fixedly installed on the bottom end of the compression sealing sleeve 301, and a plug-in groove 216 adapted to the magnetic ring 215 is opened on the top of the fixed mold 102. The inside of the plug-in groove 216 is inlaid with a magnetic plate 217 that attracts the magnetic ring 215. Through such an arrangement, the compression sealing sleeve 301 and the fixed mold 102 can form a sealed space, thereby ensuring that the top core 3 will not leak when the air is supplied before the sealing plug 303 is plugged into the fixed mold 102.

[0031] The exhaust holes 304 of the top core 3 are divided into two groups. The number of the exhaust holes 304 in the top group is greater than that in the bottom group. The diameter of the bottom group is greater than that of the top group. The air supply of the top core 3 is divided into two steps. When the bottom end is inserted, ventilation only makes the bottle blank expand to avoid adhesion, and at the same time makes the force uniform when the bottle blank is deformed. Since the inserted part is less, the exhaust holes 304 with larger diameter are set to increase the ventilation volume.

[0032] The distance between the sealing plug 303 on the outer surface of the top core 3 and the pressure plate 302 is equal to the length of the compression sealing sleeve 301 after being compressed. Through such a setting, the pressure plate 302 can squeeze the compression sealing sleeve 301 to deform, and at the same time reserve folding space for the compression sealing sleeve 301. The diameter of the pressure plate 302 is larger than the diameter of the compression sealing sleeve 301. The pressure plate 302, the upper mold 201 and the lower mold 202 are far away from each other. The surfaces are all provided with protrusions for connecting to the telescopic device. This part is a sliding unit, and the protrusions are provided for connecting with the telescopic unit.

[0033] When in use, the top core 3 is connected to the air supply mechanism and the telescopic mechanism, and the exhaust pipe 206 is connected to the vacuum mechanism and the telescopic mechanism. When the mobile unit 103 transfers the preform to the mold 2, the upper molds 201 on both sides first wrap the preform under the action of the telescopic mechanism, and the lower mold 202 is closed with the closed upper mold 201 under the action of the telescopic mechanism, so that the preform can be completely wrapped. The top core 3 is lowered to the inside of the preform under the action of the telescopic mechanism, and the exhaust pipe 206 and the upper moving part 204 are raised to the bottom of the preform under the action of the telescopic mechanism, and the through hole is leaked. At the same time, the air supply mechanism supplies air into the top core 3, and the vacuum mechanism uses the exhaust pipe 206 to exhaust air outwards. Under the action of the internal and external pressure difference, the bottle blank expands evenly. At the same time, the exhaust pipe 206 and the top core 3 descend, driving the bottle blank to stretch so that the bottle blank can be stretched evenly. The bottle blank is continuously inflated through the top core 3 so that the bottle blank can be tightly attached to the mold 2 to complete shaping. After shaping, the exhaust valve 214 is connected to control the exhaust valve 214 to exhaust the air in the bottle blank. The lower mold 202 is first separated from the upper mold 201, and then the upper molds 201 are separated from each other. The formed bottle blank is moved to the next station driven by the fixing unit 1.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0035] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lightweight plastic bottle production device, comprising a fixing unit (1) for fixing a preform, a mold (2) for wrapping the preform, and a top core (3) penetrating the fixing unit (1) and extending into the interior of the preform, characterized in that: The mold (2) comprises an upper mold (201) whose top end is symmetrically opened toward both sides, and a lower mold (202) whose bottom end moves upward to be engaged with the closed upper mold (201); A boss (203) for molding is arranged in the middle of the lower mold (202), the boss (203) is divided into an upper movable portion (204) and a fixed portion (205) at the bottom end, an exhaust pipe (206) with a through hole on the surface is slidably connected to the middle of the lower mold (202), and the top end of the exhaust pipe (206) is fixedly connected to the upper movable portion (204); The outer surface of the top core (3) is sleeved with a compression sealing sleeve (301), the compression sealing sleeve (301) is connected to the fixed unit (1) to form a seal, a pressure plate (302) is fixedly installed on the end of the surface of the top core (3) located outside the compression sealing sleeve (301), a sealing plug (303) is fixedly installed on the end of the top core (3) located inside the compression sealing sleeve (301), the sealing plug (303) is plugged into the inside of the fixed unit (1), an exhaust hole (304) for exhaust is opened on the outer surface of the top core (3) located below the sealing plug (303), and a pressure plate (305) with a smooth surface that fits the upper movable part (204) is fixedly installed on the bottom end of the top core (3).

2. A lightweight plastic bottle production device according to claim 1, characterized in that: The bottom edge of the upper mold (201) is provided with a plug-in ring groove (207), and the top of the lower mold (202) is fixedly provided with a plug-in ring block (208). When the plug-in ring block (208) and the plug-in ring groove (207) are closed, the lower mold (202), the upper mold (201) and the fixing unit (1) form a closed cavity.

3. A lightweight plastic bottle production device according to claim 1, characterized in that: The fixing unit (1) comprises a sliding die (101) whose two sides are pressed towards each other to form a threaded opening, and a fixing die (102) located in the threaded opening, wherein a moving unit (103) for controlling the movement of the sliding die (101) is fixedly mounted on the outer surface of the fixing die (102).

4. A lightweight plastic bottle production device according to any one of claims 1 to 3, characterized in that: The surface of the lower mold (202) is connected to and penetrated by an extension tube (209); the exhaust pipe (206) is slidably connected to the inside of the extension tube (209); the bottom end of the exhaust pipe (206) is connected to and penetrated by a grille portion (210); a push rod (211) is fixedly installed at the bottom end of the grille portion (210); the push rod (211) penetrates the extension tube (209) and extends to the outside of the extension tube (209); and the bottom end of the side wall of the extension tube (209) is connected to and penetrated by an exhaust port (218).

5. A lightweight plastic bottle production device according to claim 4, characterized in that: A sealing ring (212) is inlaid on the top of the outer surface of the exhaust pipe (206), and the sealing ring (212) is located above the through hole portion of the exhaust pipe (206).

6. A lightweight plastic bottle production device according to any one of claims 1 to 3 or 5, characterized in that: The air inlet end of the top core (3) is connected to and penetrates a solenoid valve (213) with three inlets and one outlet, the solenoid valve (213) controlling one of the three inlets to be connected to the outlet, one of the inlets being connected to and penetrates a controlled exhaust valve (214), another inlet being connected to a hot air pipe, and the remaining inlet being connected to a cold air pipe.

7. A lightweight plastic bottle production device according to claim 6, characterized in that: The bottom and top ends of the compression sealing sleeve (301) are both hard parts, and the middle connection is a flexible and retractable soft part. A magnetic attraction ring (215) is fixedly installed at the bottom end of the compression sealing sleeve (301), and a plug-in slot (216) adapted to the magnetic attraction ring (215) is provided at the top end of the fixed mold (102), and a magnetic plate (217) that attracts the magnetic attraction ring (215) is embedded inside the plug-in slot (216).

8. A lightweight plastic bottle production device according to claim 7, characterized in that: The exhaust holes (304) of the top core (3) are divided into two groups, the number of the top group is greater than the number of the bottom group, and the diameter of the bottom group is greater than the diameter of the top group.

9. A lightweight plastic bottle production device according to claim 8, characterized in that: The distance between the sealing plug (303) on the outer surface of the top core (3) and the pressing plate (302) is equal to the length of the compression sealing sleeve (301) after being compressed, the diameter of the pressing plate (302) is greater than the diameter of the compression sealing sleeve (301), and the surfaces of the pressing plate (302), the upper mold (201) and the lower mold (202) that are away from each other are all provided with protrusions connected to the telescopic device.

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