Production process of high-strength plastic bottle

Abstract

The invention relates to a production process of a high-strength plastic bottle. The method comprises the steps of extruding a pipe blank; feeding an inner plug; cutting off the pipe blank; closing the blow molding mold; transferring to a blow molding station; blow molding and cooling; transferring to a blanking station; taking out the inner plug and blanking; and trimming the bottle body. The pipe blank is cut off through the effect that the cut-off die is completely attached to the outer contour of the inner plug after die assembly, so that the cut-off portion of the upper end of the pipe blank is neat, the cut-off pipe blank can integrally move along with the blow molding die, the multi-station rotating table can drive the blow molding die to be switched among the extrusion station, the blow molding station and the discharging station, and the blow molding efficiency is improved. Therefore, the retention time of the blow molding die at the extrusion station is obviously reduced, and the overall production efficiency can be improved.

Description

Technical Field

[0001] The invention relates to a blow molding process, in particular to a high-strength plastic bottle production process. Background Art

[0002] Plastic bottles are generally made by blow molding, and continuous extrusion blow molding is a sub-category of existing blow molding processes. This blow molding process is suitable for the rapid production of small products. The extruder is used to continuously produce parisons, which enter the split mold on a turntable one by one, and then the mold is closed, inflated, cooled, and ejected in sequence. For details, please refer to the attached Figure 1 In the continuous extrusion blow molding process, the upper end of the preform is always connected to the extruder during the blowing and cooling process. Therefore, the extruder can only make the next preform after the plastic bottle is completely solidified and cut off. Therefore, the overall production efficiency is relatively low. Summary of the invention

[0003] The invention provides a high-strength plastic bottle production process, which solves the problem of relatively low production efficiency of the continuous extrusion blow molding process in the prior art.

[0004] The above technical problems of the present invention are mainly solved by the following technical solutions: A high-strength plastic bottle production process, which comprises:

[0005] Extruding the tube embryo, the extrusion device extrude the semi-molten tube embryo, and the tube embryo naturally droops to a certain length;

[0006] Insert the inner plug, and use a long rod with a lifting effect to insert the inner plug from the lower opening of the tube embryo to a predetermined height, and the outer diameter of the inner plug is smaller than the inner diameter of the tube embryo;

[0007] Cut off the tube embryo, close the cutting mold, so that the inner plug is clamped by the cutting mold, the tube embryo outside the inner plug is completely cut off, and the upper end of the cut tube embryo is clamped and fixed between the inner plug and the cutting mold, and at the same time, the long rod is separated from the inner plug and withdrawn from the tube embryo;

[0008] The blow mold is closed. The blow mold located below the truncation mold is closed and the lower end of the tube embryo is truncated at the same time. At this time, the tube embryo is located in the blow mold as a whole and the lower end of the tube embryo is closed;

[0009] Transfer to the blow molding station, and use the multi-station rotating table to transfer the blow molding mold after mold closing to the blow molding station, which is equipped with a blowing end with lifting function;

[0010] Blow molding cooling, the inner plug is formed with an air port that passes through from top to bottom, the blowing end on the blow molding station is connected with the air port on the inner plug, and starts blowing until the blow molding is complete, the blow mold starts to cool down with cold water, and the blowing end is in a pressure-maintaining state until the plastic part is completely solidified, and the blowing end is separated from the inner plug;

[0011] Transfer to the unloading station, the multi-station rotary table transfers the blow mold to the unloading station, which is equipped with an electromagnetic end with lifting function;

[0012] Take out the inner plug and unload the material. The electromagnetic end contacts the upper end of the inner plug, the cut-off mold opens, the electromagnetic end rises to suck out the inner plug, and finally transfers the inner plug to cooperate with the top of the long rod, then the blow molding mold opens and takes out the plastic bottle;

[0013] Bottle trimming: cutting off and grinding the excess parts of the plastic bottle.

[0014] The present invention utilizes the effect of the truncation mold being completely fitted with the outer contour of the inner plug after the mold is closed to cut off the tube embryo, so that the cut-off portion of the upper end of the tube embryo is neat, and the cut tube embryo can move with the blow molding mold as a whole. The multi-station turntable can drive the blow molding mold to switch between the extrusion station, the blow molding station and the unloading station, which significantly reduces the residence time of the blow molding mold at the extrusion station, which is beneficial to improving the overall production efficiency.

[0015] Furthermore, the process of extruding the tube blank and inserting the inner plug can also be combined, that is, the long rod first sends the inner plug to a predetermined height, at which time the inner plug is located directly below the tube blank extrusion port on the extrusion device, and then the extrusion device starts to extrude the tube blank, so that the tube blank can be sleeved on the outer side of the inner plug and the long rod during the descent process. This solution is more suitable for application when the preset cut-off length of the tube blank is longer.

[0016] Furthermore, during the process of inserting the inner plug, the long rod can continuously supply gas to the inner plug, so that the gas can be continuously output from the upper end of the gas port of the inner plug and flow downward through the annular gap between the inner plug and the tube embryo. The purpose of this design is to form a stable airflow gap between the inner plug and the tube embryo to avoid adhesion between the two and ensure that the inner plug can move smoothly in the tube embryo. It should be noted that the gas supply needs to be heated to prevent the tube embryo from solidifying when it is cold.

[0017] Furthermore, the outer contour of the inner plug is a cylindrical structure, and an annular groove is provided on its outer wall. The inner wall of the truncation mold is adapted to the outer contour of the inner plug, and an annular clamping cavity for clamping and accommodating the tube embryo is defined between the two, and the annular clamping cavity is located below the annular groove.

[0018] Furthermore, the upper end of the air port is provided with an upper positioning groove for facilitating positioning and docking with the blowing end, and the lower end of the air port is provided with a lower positioning groove for facilitating positioning and docking with the long rod.

[0019] Furthermore, the truncation mold is arranged on the upper surface of the blow mold, and the truncation mold and the blow mold have the same number of split molds, generally a 2-petal or 3-petal structure.

[0020] Therefore, compared with the prior art, the present invention has the following characteristics: 1. After completing the process of extruding the tube embryo, the present invention can use the effect of the cut-off mold after the mold is closed and the outer contour of the inner plug is completely fitted to cut the tube embryo, and then the multi-station turntable can drive the blow molding mold to switch between the extrusion station, the blow molding station and the unloading station, which significantly reduces the residence time of the blow molding mold at the extrusion station and is beneficial to improving the overall production efficiency; 2. The tube embryo is cut off by using the effect of the cut-off mold after the mold is closed and the outer contour of the inner plug is completely fitted. This cutting method can ensure that the cut-off part is relatively flat, and the lower end of the tube embryo is in a better round mouth shape, so that the inner plug feeding process can proceed smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attached Figure 1 It is a process schematic diagram of the existing continuous extrusion blow molding process;

[0022] Attached Figure 2 This is a process schematic diagram of the present invention in the process of extruding a tube embryo;

[0023] Attached Figure 3 This is a process schematic diagram of the present invention when it is in the process of feeding the inner plug;

[0024] Attached Figure 4 This is a process schematic diagram of the present invention in the process of cutting the tube embryo;

[0025] Attached Figure 5 It is a process schematic diagram of the present invention when the long rod is separated from the inner plug and withdrawn from the tube embryo during the process of cutting the tube embryo;

[0026] Attached Figure 6 It is a process schematic diagram of the present invention during the blow mold closing and blow molding cooling process;

[0027] Attached Figure 7 This is a process schematic diagram of the present invention when the inner plug is removed;

[0028] Attached Figure 8 This is the structural diagram of the inner plug. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] Embodiment 1: A high-strength plastic bottle production process, comprising:

[0032] See Figure 2 , extruding a tube embryo 1, located at the extrusion station, the extrusion device 10 extrude the semi-molten tube embryo, and the tube embryo naturally droops to a certain length;

[0033] See Figure 3 , insert the inner plug, a servo lifting platform is provided below the extrusion device, a vertical long rod 20 is provided on the servo lifting platform, an inner plug 30 is plugged into the top of the long rod, the servo lifting platform can drive the long rod to rise, and the inner plug is sent from the lower opening of the tube blank to a predetermined height, and the outer diameter of the inner plug is smaller than the inner diameter of the tube blank;

[0034] See Figure 4 and Figure 5 , cut off the tube embryo, a blow mold 40 and a cut-off mold 50 are arranged on the upper side of the servo lifting platform, and the cut-off mold is closed, so that the inner plug is clamped by the cut-off mold, and the tube embryo outside the inner plug is completely cut off, and the upper end of the cut tube embryo is clamped and fixed between the inner plug and the cut-off mold, and at the same time, the long rod is separated from the inner plug and withdrawn from the tube embryo;

[0035] See Figure 6 , the blow mold is closed, the blow mold located below the truncation mold is closed, and the lower end of the tube embryo is truncated at the same time. At this time, the tube embryo is located in the blow mold as a whole and the lower end of the tube embryo is closed;

[0036] Transfer to the blow molding station, and use the multi-station rotating table to transfer the blow molding mold after mold closing to the blow molding station, which is provided with a blowing end 60 with a lifting function;

[0037] See Figure 6 , blow molding cooling, an air port 31 that runs through from top to bottom is formed on the inner plug, the blowing end on the blow molding station is connected with the air port on the inner plug, and blowing begins until the blow molding is complete, the blow mold begins to cool down with cold water, and the blowing end is in a pressure-maintaining state until the plastic part is completely solidified, and the blowing end is separated from the inner plug;

[0038] Transfer to the unloading station, the multi-station rotary table transfers the blow mold to the unloading station, which is equipped with an electromagnetic end 70 with a lifting function;

[0039] See Figure 7 , take out the inner plug and unload the material, the electromagnetic end contacts the upper end of the inner plug, the cut-off mold opens, the electromagnetic end rises to suck out the inner plug, and finally transfers the inner plug to cooperate with the top of the long rod, then the blow molding mold opens and takes out the plastic bottle;

[0040] Bottle trimming: cutting off and grinding the excess parts of the plastic bottle.

[0041] This embodiment utilizes the effect of the truncation mold completely fitting the outer contour of the inner plug after the mold is closed to cut off the tube embryo, so that the cut-off part of the upper end of the tube embryo is neat, and the cut-off tube embryo can move with the blow molding mold as a whole. The multi-station turntable can drive the blow molding mold to switch between the extrusion station, the blow molding station and the unloading station, which significantly reduces the residence time of the blow molding mold at the extrusion station, which is beneficial to improving the overall production efficiency.

[0042] In this embodiment, the long rod is a hollow structure, and a blower and an electric heater are also provided on the servo lifting platform. The electric heater can heat the gas blown out by the blower, and the hot air is output from the upper end of the inner plug through the long rod. During the process of sending the inner plug into the inner plug, the long rod can continuously supply air to the inner plug, so that the gas can be continuously output from the upper end of the air port of the inner plug and flow downward through the annular gap between the inner plug and the tube embryo. The purpose of this design is to form a stable airflow gap between the inner plug and the tube embryo to avoid adhesion between the two and ensure that the inner plug can move smoothly in the tube embryo.

[0043] See Figure 8 In this embodiment, the outer contour of the inner plug is a cylindrical structure, and an annular groove 32 is provided on its outer wall. The inner wall of the truncation mold adapts to the outer contour of the inner plug, and an annular clamping cavity for clamping and accommodating the tube embryo is defined between the two, and the annular clamping cavity is located below the annular groove.

[0044] See Figure 8 In this embodiment, an upper positioning groove 33 is provided at the upper end of the air port for facilitating the positioning and docking with the blowing end, and a lower positioning groove 34 is provided at the lower end of the air port for facilitating the positioning and docking with the long rod.

[0045] In this embodiment, the cut-off mold is arranged on the upper surface of the blow mold, and the cut-off mold and the blow mold both have a three-petal structure.

[0046] The present invention can be modified in various ways which are obvious to those skilled in the art, and such modifications are not considered to depart from the scope of the present invention. All such modifications which are obvious to those skilled in the art are intended to be included within the scope of the present claims.

Claims

1. A high-strength plastic bottle production process, characterized in that: include: Extruding the tube embryo, the extrusion device extrude the semi-molten tube embryo, and the tube embryo naturally droops to a certain length; Insert the inner plug, and use a long rod with a lifting effect to insert the inner plug from the lower opening of the tube embryo to a predetermined height, and the outer diameter of the inner plug is smaller than the inner diameter of the tube embryo; Cut off the tube embryo, close the cutting mold, so that the inner plug is clamped by the cutting mold, the tube embryo outside the inner plug is completely cut off, and the upper end of the cut tube embryo is clamped and fixed between the inner plug and the cutting mold, and at the same time, the long rod is separated from the inner plug and withdrawn from the tube embryo; The blow mold is closed. The blow mold located below the truncation mold is closed and the lower end of the tube embryo is truncated at the same time. At this time, the tube embryo is located in the blow mold as a whole and the lower end of the tube embryo is closed; Transfer to the blow molding station, and use the multi-station rotating table to transfer the blow molding mold after mold closing to the blow molding station, which is equipped with a blowing end with lifting function; Blow molding cooling, the inner plug is formed with an air port that passes through from top to bottom, the blowing end on the blow molding station is connected with the air port on the inner plug, and starts blowing until the blow molding is complete, the blow mold starts to cool down with cold water, and the blowing end is in a pressure-maintaining state until the plastic part is completely solidified, and the blowing end is separated from the inner plug; Transfer to the unloading station, the multi-station rotary table transfers the blow mold to the unloading station, which is equipped with an electromagnetic end with lifting function; Take out the inner plug and unload the material. The electromagnetic end contacts the upper end of the inner plug, the cut-off mold opens, the electromagnetic end rises to suck out the inner plug, and finally transfers the inner plug to cooperate with the top of the long rod, then the blow molding mold opens and takes out the plastic bottle; Bottle trimming: cutting off and grinding the excess parts of the plastic bottle.

2. The high-strength plastic bottle production process according to claim 1, characterized in that: During the process of inserting the inner plug, the long rod can continuously supply air to the inner plug.

3. The high-strength plastic bottle production process according to claim 2, characterized in that: The outer contour of the inner plug is a cylindrical structure, and an annular groove is provided on its outer wall. The inner wall of the truncation mold adapts to the outer contour of the inner plug, and an annular clamping cavity for clamping and accommodating the tube embryo is defined between the two, and the annular clamping cavity is located below the annular groove.

4. The high-strength plastic bottle production process according to claim 3 is characterized in that: An upper positioning groove is provided at the upper end of the air port for facilitating positioning and docking with the blowing end, and a lower positioning groove is provided at the lower end of the air port for facilitating positioning and docking with the long rod.

5. The high-strength plastic bottle production process according to claim 1, characterized in that: The truncation mold is arranged on the upper surface of the blow mold, and the truncation mold and the blow mold have the same number of split molds, generally a 2-petal or 3-petal structure.

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