Technological shaping method for pull-down sealing structure, secondary rubber coating mold and plastic product

Abstract

The invention discloses a pull-down sealing structure process shaping method, a secondary rubber coating mold and a plastic product. The pull-down sealing structure process shaping method comprises the steps that S1, a material extruding mechanism extrudes a rubber mold blank to the position between a first mold plate and a second mold plate; s2, covering the first mold plate and the second mold plate; s3, a first sliding pull rod, a second sliding pull rod and an air blowing head extend into the hollow cavity from the lower portion; s4, the first sliding pull rod and the second sliding pull rod are used for stretching the rubber mold blank, the rubber mold blank which is pre-stretched is subjected to blow molding on the hollow cavity, and therefore the consistency of the wall thickness of a finished product can be improved; s4.1, a first sliding pull rod, a second sliding pull rod and an air blowing head are enclosed by a first sealing plate and a second sealing plate; s5, blow molding is conducted through a blow head; s6, a cooling mechanism operates; s7, the first mold plate and the first sealing plate are separated, and the second sealing plate, the second mold plate, the first sliding pull rod and the second sliding pull rod return; the plastic product is manufactured by adopting the method or the mold with the first sliding pull rod and the second sliding pull rod, so that the wall thickness consistency is good.

Description

Technical Field

[0001] The invention relates to the technical field of mold manufacturing, and in particular to a process shaping method for a pull-down sealing structure, a secondary encapsulation mold and a plastic product. Background Art

[0002] In the existing blow molding process, the blow molding process used to manufacture large-caliber plastic products such as flower pots and buckets is usually the same as that used to manufacture small-caliber plastic products. The difference is that the small-caliber part is cut off after the finished product is demoulded, thereby manufacturing large-caliber plastic products; for details, please refer to the manufacturing process of disposable mineral water bottles; however, the existing process has the following defects when manufacturing large-caliber plastic products:

[0003] On the one hand, the size of the blow head used is fixed. The blow head is inserted into the mold cavity, and the mold is closed to enclose the blow head, and then the blow head is blow-molded. The diameter of the plastic product cannot be shaped and adjusted before blow molding. On the other hand, large-diameter plastic products manufactured by the existing blow molding process have uneven wall thickness, and the product structure strength of the thin-walled parts of the plastic products is low, and the plastic products are easily damaged. For example, if the plastic products are made of colored translucent materials, the light transmittance is stronger at the complex structure of the plastic products, and the overall color of the plastic products is uneven, which affects the appearance. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a process shaping method for a pull-down sealing structure, a secondary encapsulation mold and a plastic product suitable for manufacturing large-caliber plastic products and improving the consistency of the wall thickness of the finished product.

[0005] The first technical solution adopted by the present invention to solve its technical problem is:

[0006] The process for finalizing the pull-down sealing structure is characterized by comprising the following steps:

[0007] S1, the extrusion mechanism extrudes the plastic blank having a hollow cavity between the first mold plate and the second mold plate;

[0008] S2, the first mold plate and the second mold plate are covered together to cut off the rubber blank extruded by the extrusion mechanism;

[0009] S3, the first sliding rod, the second sliding rod and the blowing head extend from below the first mold plate and the second mold plate into the hollow cavity of the rubber mold blank;

[0010] S4, the first sliding rod and the second sliding rod move relative to each other to stretch the hollow cavity of the plastic mold blank;

[0011] S4.1, the first sealing plate and the second sealing plate are brought closer to each other, enclosing the first sliding rod, the second sliding rod and the blowing head to seal the hollow cavity;

[0012] S5, the blowing head blows air into the hollow cavity, and the plastic mold blank expands and fits the inner walls of the first mold plate and the second mold plate;

[0013] S6, the cooling mechanism of the outer wall of the first mold plate and the second mold plate is operated to reduce the temperature and cool the first mold plate and the second mold plate;

[0014] S7, separating the first mold plate and the first sealing plate, the second sealing plate, and the second mold plate, and retracting the first sliding rod and the second sliding rod to obtain a molded plastic product.

[0015] According to the process for finalizing the pull-down sealing structure as described above, the inner walls of the first mold plate and the second mold plate include a changing portion and a smooth portion;

[0016] In step S2, the extrusion mechanism extrudes material until the thickness of the rubber blank at the changing portion is greater than the thickness of the rubber blank at the smooth portion.

[0017] The process for finalizing the pull-down sealing structure as described above further includes step S5.1 and step S6.2;

[0018] Wherein, step S5.1: the first movable module on the first mold plate and the second movable module on the second mold plate move toward the changing portion to squeeze the plastic mold blank of the changing portion so that the plastic mold blank located at the changing portion is attached to the inner walls of the first mold plate and the second mold plate;

[0019] Wherein, step S6.1: the first active module and the second active module are reset.

[0020] The process for finalizing the pull-down sealing structure as described above further includes step S2.1

[0021] Among them, it also includes steps S4.2 and S6.2,

[0022] Wherein, in step S4.2, the first cover plate driving member drives the first cover plate to rise and fall relative to the first mold plate, and the second cover plate driving member drives the second cover plate to rise and fall relative to the second mold plate, so that the first cover plate and the second cover plate squeeze the rubber blank;

[0023] In step S6.2, the first cover plate and the second cover plate are reset.

[0024] In the process shaping method of the pull-down sealing structure as described above, step S2 includes: the lifting drive member drives the inner die nozzle to lift relative to the outer die nozzle, thereby adjusting the width of the discharge channel between the outer wall of the inner die nozzle and the inner wall of the outer die nozzle to control the thickness of the extruded rubber blank.

[0025] The second technical solution adopted by the present invention to solve its technical problem is:

[0026] A secondary overmolding mold, comprising a first mold plate and a second mold plate;

[0027] The first mold plate and the second mold plate enclose an injection cavity;

[0028] The first mold plate and the second mold plate are provided with a material extrusion mechanism on the top;

[0029] The bottom of the first mold plate and the second mold plate is provided with a base, a first sliding rod, a slide rail, a second sliding rod and a blowing head;

[0030] The air blowing head is arranged directly below the extruding mechanism and is fixedly connected to the base, and the air blowing head is arranged between the first sliding rod and the second sliding rod;

[0031] The slide rail is arranged on the base, and the first sliding rod and the second sliding rod are slidably arranged on the slide rail.

[0032] The secondary overmolding mold as described above, wherein the extrusion mechanism comprises an inner die nozzle, an outer die nozzle and a lifting drive member;

[0033] The inner die nozzle is in a truncated cone shape, and has a bottom surface and a top surface, the diameter of the bottom surface is greater than the diameter of the top surface, and the bottom surface is arranged toward the first die plate and the second die plate;

[0034] The inner wall of the inner cavity of the outer die nozzle is geometrically matched with the outer wall of the inner die nozzle;

[0035] A discharge channel is provided between the inner wall of the outer die nozzle and the outer wall of the inner die nozzle;

[0036] The output end of the lifting drive member is fixedly connected to the inner die nozzle, and the lifting drive member can drive the inner die nozzle to move relative to the outer die nozzle.

[0037] In the secondary overmolding mold as described above, the inner cavity of the inner mold nozzle is a truncated cone-shaped cavity.

[0038] The secondary overmolding mold as described above further comprises a base lifting drive member, wherein an output end of the base lifting drive member is fixedly connected to the base, and the blowing head is arranged on the base;

[0039] The base lifting drive member can drive the blowing head, the first sliding rod and the second sliding rod to move relative to the injection cavity.

[0040] As described above, the secondary overmolding mold further has a reverse synchronous drive mechanism on the base, which is arranged on the side of the slide rail, one end of the reverse synchronous drive mechanism is fixedly connected to the first sliding rod, and the other end of the reverse synchronous drive mechanism is fixedly connected to the second sliding rod.

[0041] The third technical solution adopted by the present invention to solve its technical problem is: a plastic product, which is prepared by adopting the above-mentioned pull-down sealing structure process shaping method or is made by the above-mentioned secondary encapsulation mold.

[0042] The beneficial effects of the present invention are:

[0043] The provided process shaping method of the pull-down sealing structure pre-stretches the rubber blank by means of the first sliding rod and the second sliding rod, and then the rubber blank is blow-molded into the hollow cavity, thereby improving the consistency of the wall thickness of the finished product;

[0044] The secondary encapsulation mold provided is provided with a first sliding pull rod and a second sliding pull rod to pre-stretch the rubber mold blank, and then the rubber mold blank is blow-molded to the hollow cavity, thereby improving the consistency of the wall thickness of the finished product;

[0045] A plastic product, because it is made by adopting the above-mentioned pull-down sealing structure process shaping method or the secondary encapsulation mold, has good wall thickness consistency and high structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0047] Figure 1 It is a schematic diagram of the structure of the secondary overmolding mold;

[0048] Figure 2 It is one of the structural schematic diagrams of the first mold plate;

[0049] Figure 3 This is the second structural schematic diagram of the first mold plate;

[0050] Figure 4 is a schematic diagram of the structure of the covering fixing module;

[0051] Figure 5 It is one of the structural schematic diagrams of the second mold plate;

[0052] Figure 6 This is the second structural schematic diagram of the second mold plate;

[0053] Figure 7 It is a structural schematic diagram of a base, a first sliding rod, a slide rail, a second sliding rod, an air blowing head, and a reverse synchronous driving mechanism;

[0054] Figure 8It is one of the motion state diagrams of the extrusion mechanism;

[0055] Fig. 9 This is the second motion state diagram of the extrusion mechanism;

[0056] Fig.10 This is a schematic diagram of the structure of a large-diameter plastic barrel with secondary rubber coating;

[0057] 1. First mold plate; 12. Changing part; 121. First changing part; 122. Second changing part; 14. First movable module; 15. Covering part fixing module; 151. First propulsion cylinder; 152. First slider; 1521. Groove; 153. First fixing block; 161. First cover plate; 162. First cover plate driving member; 2. Second mold plate; 21. Smoothing part; 24. Second movable module; 261. Second cover plate; 262. Second cover plate driving member; 31. Base; 32. First sliding rod; 33. Slide rail; 34. Second sliding rod; 35. Blowing head; 37. Reverse synchronous driving mechanism; 4. Extruding mechanism; 41. Inner mold nozzle; 411. Bottom surface; 412. Top surface; 42. Outer mold nozzle; 44. Discharging passage Road; 61, the first sealing plate; 63, the first driving group; 631, the first fixed plate; 632, the second fixed plate; 633, the first sealing plate driving member; 62, the second sealing plate; 64, the second driving group; 641, the third fixed plate; 642, the fourth fixed plate; 643, the second sealing plate driving member; 71, the injection handle; 72, the handle; 81, the first handle extrusion molding module; 811, the first upper extrusion module; 812, the first upper extrusion module driving member; 813, the first lower extrusion module; 814, the first lower extrusion module driving member; 82, the second handle extrusion molding module; 821, the second upper extrusion module; 822, the second upper extrusion module driving member; 823, the second lower extrusion module; 824, the second lower extrusion module driving member. DETAILED DESCRIPTION

[0058] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the present invention. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the invention can be combined interchangeably without conflicting with each other.

[0059] Embodiment 1:

[0060] The process for finalizing the pull-down sealing structure comprises the following steps:

[0061] S1a, the extrusion mechanism 4 extrudes the plastic preform 5 having a hollow cavity between the first mold plate 1 and the second mold plate 2;

[0062] Prepare for blow molding of the blow head 35;

[0063] The first mold plate 1 and the second mold plate 2 can be integrated or composed of mold plates divided into several pieces. As long as the modules can completely enclose the plastic mold blank 5 after closing, they all belong to the matching relationship between the first mold plate 1 and the second mold plate 2 referred to in this application (the same below);

[0064] S2a, the first mold plate 1 and the second mold plate 2 are covered, and the rubber blank 5 extruded by the extrusion mechanism 4 is cut off;

[0065] Specifically, the rubber blank 5 can be cut by the first mold plate 1 and the second mold plate 2 covering each other at the same time, or can be cut by an external cutter (the same below);

[0066] S3a, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 extend from below the first mold plate 1 and the second mold plate 2 into the hollow cavity of the plastic mold 5;

[0067] S4a, the first sliding rod 32 and the second sliding rod 34 move relative to each other to stretch the hollow cavity of the plastic mold blank 5;

[0068] S4.1a, the first sealing plate 61 and the second sealing plate 62 are brought closer to each other, enclosing the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to close the hollow cavity;

[0069] Specifically, the plastic mold blank 5 on the same horizontal cross section is expanded so that the plastic product can be adjusted before blow molding;

[0070] S5a, the blowing head 35 blows air into the hollow cavity, and the plastic mold 5 expands and fits the inner walls of the first mold plate 1 and the second mold plate 2;

[0071] S6a, the cooling mechanism of the outer wall of the first mold plate 1 and the second mold plate 2 is operated to reduce the temperature and cool the first mold plate 1 and the second mold plate 2;

[0072] Specifically, the cooling mechanism of this part is any existing one, such as a cold water cooling mechanism, which will not be described in detail here, and plays the role of reducing the temperature of the rubber preform 5 in the first mold plate 1 and the second mold plate 2;

[0073] S7a, separate the first mold plate 1 and the second mold plate 2, and retract the first sealing plate 61, the second sealing plate 62, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to obtain a molded plastic product A1.

[0074] Embodiment 2:

[0075] A method for finalizing a process for preparing a pull-down sealing structure for a plastic product with a complex shape comprises the following steps:

[0076] S1b, the inner wall of the first mold plate 1 and the second mold plate 2 includes a change portion 12 and a smooth portion 21;

[0077] Specifically, the change portion 12 refers to a portion with decorative complex patterns or patterns, a handle portion, a recessed portion, an edge corner portion where stress is concentrated, a portion connected to a connector (screw hole, buckle), and a portion where a reinforcing rib is provided. Specifically, the change portion 12 is uneven in appearance; the smooth portion 21 is the opposite, and the appearance of the smooth portion 21 is continuous and flat (the same below);

[0078] The extrusion mechanism 4 extrudes the rubber preform 5 having a hollow cavity between the first mold plate 1 and the second mold plate 2;

[0079] Specifically, the thickness of the rubber blank 5 squeezed by the squeezing mechanism 4 to the changing portion 12 is greater than the thickness of the rubber blank 5 squeezed to the smooth portion 21;

[0080] S2b, the first mold plate 1 and the second mold plate 2 are covered together to cut off the rubber blank 5 extruded by the extrusion mechanism 4;

[0081] S3b, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 extend from below the first mold plate 1 and the second mold plate 2 into the hollow cavity of the plastic mold 5;

[0082] S4b, the first sliding rod 32 and the second sliding rod 34 move relative to each other to stretch the hollow cavity of the plastic mold blank 5, wherein the stretching range of the changing portion 12 is greater than that of the smooth portion 21. Since in step S1b, the thickness of the plastic mold blank 5 of the changing portion 12 is greater than the thickness of the plastic mold blank 5 of the smooth portion 21, the first sliding rod 32 and the second sliding rod 34 are stretched in this step to reduce the wall thickness of the changing portion 12, thereby improving the consistency of the wall thickness of the changing portion 12 and the smooth portion 21 in the plastic product A2;

[0083] S4.1b, the first sealing plate 61 and the second sealing plate 62 are brought closer to each other, enclosing the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to close the hollow cavity;

[0084] S5b, the blowing head 35 blows air into the hollow cavity, and the plastic mold 5 expands and fits the inner walls of the first mold plate 1 and the second mold plate 2; at this time, the blowing of the blowing head 35 also has the effect of further uniformizing the wall thickness of the changing part 12 and the smooth part 21;

[0085] S5.1b: The first movable module 14 located at the changing portion 12 of the first mold plate 1 and the second movable module 24 located at the changing portion 12 of the second mold plate 2 squeeze the plastic mold blank 5 in the changing portion 12 to make the plastic mold blank 5 fit with the inner walls of the first mold plate 1 and the second mold plate 2;

[0086] S6b, the cooling mechanism of the outer wall of the first mold plate 1 and the second mold plate 2 is operated to reduce the temperature and cool the first mold plate 1 and the second mold plate 2;

[0087] S6.1b, the first active module 14 and the second active module 24 are reset;

[0088] S7b, separate the first mold plate 1 and the second mold plate 2, and retract the first sealing plate 61, the second sealing plate 62, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to obtain a molded plastic product.

[0089] Embodiment 3:

[0090] A method for preparing a pull-down sealing structure process for a large-caliber plastic barrel with a complex structure comprises the following steps:

[0091] The first movable module 14 includes a covering fixing module 15 and a first handle extrusion molding module 81; the second movable module 24 includes a second handle extrusion molding module 82;

[0092] S1c, the extrusion mechanism 4 extrudes the plastic preform 5 with a hollow cavity to between the first mold plate 1 and the second mold plate 2, the mold cavity enclosed by the first mold plate 1 and the second mold plate 2 opens downward, and the extrusion mechanism 4 is arranged above the first mold plate 1 and the second mold plate 2;

[0093] Specifically, the inner walls of the first mold plate 1 and the second mold plate 2 include a change portion 12 where the handle is set and a smooth portion 21;

[0094] The thickness of the rubber blank 5 extruded to the change portion 12 is greater than the thickness of the rubber blank 5 at the smooth portion 21, that is, the thickness of the rubber blank 5 changes from thin to thick;

[0095] S2c, the first mold plate 1 and the second mold plate 2 are covered, and the rubber blank 5 extruded by the extrusion mechanism 4 is cut off;

[0096] S3c, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 extend from below the first mold plate 1 and the second mold plate 2 into the hollow cavity of the plastic mold 5;

[0097] S4c, the first sliding rod 32 and the second sliding rod 34 move relative to each other to stretch the hollow cavity of the plastic mold 5 to form a large diameter;

[0098] S4.1c, the first sealing plate 61 and the second sealing plate 62 are brought closer to each other, enclosing the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to close the hollow cavity;

[0099] S4.2, the first cover plate driving member 162 drives the first cover plate 161 to rise and fall relative to the first mold plate 1, and the second cover plate driving member 262 drives the second cover plate 261 to rise and fall relative to the second mold plate 2, so that the first cover plate 161 and the second cover plate 261 squeeze the plastic mold blank 5;

[0100] S5c, the blowing head 35 blows air into the hollow cavity, and the plastic mold 5 expands and fits the inner walls of the first mold plate 1 and the second mold plate 2;

[0101] S5.1d, the first handle extrusion molding module 81 includes a first upper extrusion module 811, a first upper extrusion module driving member 812 that drives the first upper extrusion module 811 to move, a first lower extrusion module 813, and a first lower extrusion module driving member 814 that drives the first lower extrusion module 813 to move;

[0102] The second handle extrusion molding module 82 includes a second upper extrusion module 821, a second upper extrusion module driving member 822 driving the second upper extrusion module 821 to move, a second lower extrusion module 823, and a second lower extrusion module driving member 824 driving the second lower extrusion module 823 to move;

[0103] The first upper extrusion module driving member 812 drives the first upper extrusion module 811 to move toward the first lower extrusion module 813, and the first lower extrusion module driving member 814 drives the first lower extrusion module 813 to move toward the first upper extrusion module driving member 812; at the same time, the second upper extrusion module driving member 822 drives the second upper extrusion module 821 to move toward the second lower extrusion module 823, and the second lower extrusion module driving member 824 drives the second lower extrusion module 823 to move toward the second upper extrusion module 821, thereby extruding the rubber blank 5 located at the second changing portion 122, so that the rubber blank 5 located at the second changing portion 122 is attached to the inner walls of the first mold plate 1 and the second mold plate 2 to form a handle 72;

[0104] S6c, the cooling mechanism of the outer wall of the first mold plate 1 and the second mold plate 2 is operated to reduce the temperature and cool the first mold plate 1 and the second mold plate 2;

[0105] S6.1c. The first active module 14 and the second active module 24 are reset.

[0106] S6.2, the first cover plate 161 and the second cover plate 261 are reset;

[0107] S7c, separate the first mold plate 1 and the second mold plate 2, and retract the first cover plate 161, the second cover plate 261, the first sealing plate 61, the second sealing plate 62, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to obtain a large-diameter plastic barrel.

[0108] Embodiment 4:

[0109] A method for finalizing the process of preparing a pull-down sealing structure of a large-diameter plastic barrel with a complex structure and a secondary rubber coating, wherein the large-diameter plastic barrel has an injection-molded handle 71 at the bottom and a handle 72 at the top of the opening;

[0110] The first movable module 14 includes a covering fixing module 15 and a first handle extrusion molding module 81; the second movable module 24 includes a second handle extrusion molding module 82;

[0111] The following steps are involved:

[0112] S0-1. A covering fixing module 15 (in this embodiment, a covering injection molding handle 71, hereinafter referred to as the injection molding handle 71) is also provided on the first mold plate 1. The covering fixing module 15 includes a first propulsion cylinder 151, a first sliding block 152 and a first fixing block 153;

[0113] The first slider 152 is provided with a groove 1521 for placing the injection handle. The first slider 152 and the first fixing block 153 are provided with magnets that can attract each other. The first slider 152 and the first fixing block 153 are closed to fix the injection handle 71 in the groove 1521.

[0114] Specifically, the first push cylinder 151 drives the first slide block 152 to move into the mold cavity, and the injection handle 71 and the first fixing block 153 are placed in the groove 1521 respectively; at this time, due to the placement of the injection handle 71, the area where the part to be covered is located belongs to the change portion 12. In order to distinguish it from the change portion 12 of the handle part, the area where the part to be covered is located is called the first change portion 121, and the area where the handle is extruded is called the second change portion 122.

[0115] S1d, the extrusion mechanism 4 extrudes the plastic preform 5 with a hollow cavity to between the first mold plate 1 and the second mold plate 2; the mold cavity enclosed by the first mold plate 1 and the second mold plate 2 opens downward, and the extrusion mechanism 4 is arranged above the first mold plate 1 and the second mold plate 2;

[0116] Specifically, the inner walls of the first mold plate 1 and the second mold plate 2 include a change portion 12 and a smooth portion 21 on which the parts to be covered and the handle are installed;

[0117] The thickness of the rubber blank 5 extruded to the change portion 12 is greater than the thickness of the rubber blank 5 at the smooth portion 21 , that is, the thickness of the rubber blank 5 changes from thick (corresponding to the injection molding handle 71 ) to thin and then to thick (corresponding to the injection molding handle 72 );

[0118] The first mold plate 1 is provided with a first cover plate 161 and a first cover plate driving member 162 at one end facing away from the extrusion mechanism 4, and the second mold plate 2 is provided with a second cover plate 261 and a second cover plate driving member 262 at one end facing away from the extrusion mechanism 4;

[0119] The fixed end of the first cover plate driving member 162 is connected to the first mold plate 1, and the output end of the first cover plate driving member 162 is connected to the first cover plate 161; the fixed end of the second cover plate driving member 262 is connected to the second mold plate 2, and the output end of the second cover plate driving member 262 is connected to the second cover plate 261;

[0120] S3d, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 extend from below the first mold plate 1 and the second mold plate 2 into the hollow cavity of the plastic mold 5; (the order of this step can be interchanged with S2.1d)

[0121] S4d, the first sliding rod 32 and the second sliding rod 34 move relative to each other to stretch the hollow cavity of the plastic mold 5 to form a large diameter;

[0122] S4.1, the first sealing plate 61 and the second sealing plate 62 are brought closer to each other, enclosing the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to close the hollow cavity;

[0123] S4.2, the first cover plate driving member 162 drives the first cover plate 161 to rise and fall relative to the first mold plate 1, and the second cover plate driving member 262 drives the second cover plate 261 to rise and fall relative to the second mold plate 2, so that the first cover plate 161 and the second cover plate 261 squeeze the rubber preform 5 in the mold cavity, so that the rubber preform 5 facing away from the extrusion mechanism 4 moves toward the extrusion mechanism 4 under the action of squeezing;

[0124] S5d, the blowing head 35 blows air into the hollow cavity, and the plastic mold 5 expands and fits the inner walls of the first mold plate 1 and the second mold plate 2; (S4.2 and S5 can be performed simultaneously)

[0125] At this point, the coating of the injection molded handle 71 is completed;

[0126] S5.1d, the first handle extrusion molding module 81 includes a first upper extrusion module 811, a first upper extrusion module driving member 812 that drives the first upper extrusion module 811 to move, a first lower extrusion module 813, and a first lower extrusion module driving member 814 that drives the first lower extrusion module 813 to move;

[0127] The second handle extrusion molding module 82 includes a second upper extrusion module 821, a second upper extrusion module driving member 822 driving the second upper extrusion module 821 to move, a second lower extrusion module 823, and a second lower extrusion module driving member 824 driving the second lower extrusion module 823 to move;

[0128] The first upper extrusion module driving member 812 drives the first upper extrusion module 811 to move toward the first lower extrusion module 813, and the first lower extrusion module driving member 814 drives the first lower extrusion module 813 to move toward the first upper extrusion module driving member 812; at the same time, the second upper extrusion module driving member 822 drives the second upper extrusion module 821 to move toward the second lower extrusion module 823, and the second lower extrusion module driving member 824 drives the second lower extrusion module 823 to move toward the second upper extrusion module 821, thereby extruding the rubber blank 5 located at the second changing portion 122, so that the rubber blank 5 located at the second changing portion 122 is attached to the inner walls of the first mold plate 1 and the second mold plate 2 to form a handle 72;

[0129] S6d, the cooling mechanism of the outer wall of the first mold plate 1 and the second mold plate 2 is operated to reduce the temperature and cool the first mold plate 1 and the second mold plate 2;

[0130] S6.1d, the first active module 14 and the second active module 24 are reset;

[0131] S6.2d, the first cover plate 161 and the second cover plate 261 are reset;

[0132] S7d, separate the first mold plate 1 and the second mold plate 2, and retract the first cover plate 161, the second cover plate 261, the first sealing plate 61, the second sealing plate 62, the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to obtain a secondary rubber-encapsulated large-diameter plastic barrel.

[0133] The secondary encapsulation process in the prior art is generally manufactured using an ordinary blow molding mold. The module to be coated is placed in the blow molding mold. The front mold and the rear mold of the blow molding mold are molded together and the blow molding is completed. Although the encapsulation blow molding process in the prior art is simple, with the development of science and technology and the needs of the people, the functions of blow molding products have become diversified, and many products have become more and more complex. The simple secondary encapsulation process gradually shows the following problems:

[0134] ①Poor module coating effect: The module is placed in the inner wall of the blow mold, and the side wall of the mold and the inner wall of the blow mold have an angle or a small gap. Due to the narrow path at the gap, the fluidity of the molten plastic will be slowed down, and the molten plastic in the gap will solidify prematurely, hindering the further flow and filling of the molten plastic, or forming air pockets at the gap, thereby reducing the module's coating effect, and the module is easy to fall off from the secondary encapsulation shell;

[0135] ② It is not suitable for manufacturing products with complex shapes: complex-shaped molds have more places where the internal shape changes dramatically, and the flow path of the molten plastic is more complicated and the flow speed slows down at the places where the shape changes dramatically. The molten plastic will also solidify prematurely; and during blow molding, it is more difficult to apply uniform pressure inside the mold, and the corners of the mold are more likely to be difficult to be fully filled due to insufficient pressure.

[0136] Reference Figure 1 , Figure 2 , a secondary overmolding mold, comprising a first mold plate 1 and a second mold plate 2;

[0137] The first mold plate 1 and the second mold plate 2 enclose an injection cavity;

[0138] The first mold plate 1 and the second mold plate 2 are provided with a material extrusion mechanism 4 on the top;

[0139] The first mold plate 1 and the second mold plate 2 are provided with a base 31, a first sliding rod 32, a slide rail 33, a second sliding rod 34 and a blowing head 35 at the bottom;

[0140] The blowing head 35 is disposed directly below the extruding mechanism 4 and is fixedly connected to the base 31 . The blowing head 35 is disposed between the first sliding rod 32 and the second sliding rod 34 .

[0141] The slide rail 33 is disposed on the base 31 , and the first sliding rod 32 and the second sliding rod 34 are slidably disposed on the slide rail 33 .

[0142] The first sliding rod 32 and the second sliding rod 34 are provided to facilitate the pulling and stretching of the hollow cavity 5 of the rubber mold blank 5;

[0143] Specifically, it also includes a first drive group 63 and a second drive group 64;

[0144] The first driving group 63 includes a first fixing plate 631 disposed on the first mold plate 1, a second fixing plate 632 is disposed on the first sealing plate 61, a first sealing plate driving member 633 is disposed between the first fixing plate 631 and the second fixing plate 632, a fixing end of the first sealing plate driving member 633 is connected to the first fixing plate 631, and an output end of the first sealing plate driving member 633 is connected to the second fixing plate 632;

[0145] The second driving group 64 includes a third fixing plate 641 disposed on the second mold plate 1, a fourth fixing plate 642 is disposed on the second sealing plate 62, a second sealing plate driving member 643 is disposed between the third fixing plate 641 and the fourth fixing plate 642, a fixed end of the second sealing plate driving member 643 is connected to the third fixing plate 641, and an output end of the second sealing plate driving member 643 is connected to the fourth fixing plate 642;

[0146] The first sealing plate driving member 633 and the second sealing plate driving member 643 extend to drive the first sealing plate 61 and the second sealing plate 62 to approach each other, so as to enclose the first sliding rod 32, the second sliding rod 34 and the blowing head 35, and form a closed space for the blowing head 35 to blow mold. After the blow molding is completed, the first sealing plate driving member 633 and the second sealing plate driving member 643 retract to allow the first sliding rod 32, the second sliding rod 34 and the blowing head 35 to return to their original positions;

[0147] The first sealing plate driving member 633 and the second sealing plate driving member 643 may be cylinders;

[0148] Furthermore, the extrusion mechanism 4 includes an inner die nozzle 41, an outer die nozzle 42 and a lifting drive member (not shown in the figure);

[0149] The inner die nozzle 41 is truncated cone-shaped, and has a bottom surface 411 and a top surface 412. The diameter of the bottom surface 411 is greater than the diameter of the top surface 412. The bottom surface 411 is disposed toward the first die plate 1 and the second die plate 2.

[0150] The inner wall of the inner cavity of the outer die nozzle 42 is geometrically matched with the outer wall of the inner die nozzle 41;

[0151] A discharge channel 44 is provided between the inner wall of the outer die nozzle 42 and the outer wall of the inner die nozzle 41;

[0152] The output end of the lifting drive member is fixedly connected to the inner die nozzle 41 , and the lifting drive member can drive the inner die nozzle 41 to move relative to the outer die nozzle 42 .

[0153] The inner cavity of the outer die nozzle 42 is geometrically matched with the outer wall of the inner die nozzle 41, which ensures the consistency and stability of the discharge channel 44 and helps to reduce the resistance and deformation during the material flow process.

[0154] Specifically, the inner cavity of the inner die nozzle 41 is a truncated cone-shaped cavity, that is, when discharging the material, the widths of the two side walls of the discharge channel 44 are parallel to each other. Figure 5-Figure 6 As shown, in this way, the preform 5 will not be stuck on the outer wall of the inner die nozzle 41 or the outer die nozzle 42, reducing the probability of clogging of the discharge channel 44, and when cleaning is needed, the continuous wall surface is also easy to clean, reducing the production cycle being forced to be delayed due to the blockage of the extrusion mechanism 4.

[0155] Furthermore, it includes a base lifting drive member (not shown in the figure), which is a truncated cone-shaped cavity. The output end of the base lifting drive member is fixedly connected to the base 31, and the blowing head 35 is arranged on the base 31;

[0156] The base lifting drive member can drive the blowing head 35, the first sliding rod 32 and the second sliding rod 34 to move relative to the injection cavity.

[0157] For example, after the hollow cavity 5 of the rubber mold blank 5 is stretched by the first sliding rod 32 and the second sliding rod 34, the blowing head 35 is inserted. At this time, since the hollow cavity 5 is stretched, the entrance of the blowing head 35 will become narrower, making it difficult to insert the blowing head 35. The present solution provides a base lifting drive member to drive the blowing head 35, the first sliding rod 32 and the second sliding rod 34 to rise and fall synchronously, thereby solving the above problem.

[0158] Furthermore, a reverse synchronous drive mechanism 37 is also provided on the base 31, and the reverse synchronous drive mechanism 37 is provided on the side of the slide rail 33, one end of the reverse synchronous drive mechanism 37 is fixedly connected to the first sliding rod 32, and the other end of the reverse synchronous drive mechanism 37 is fixedly connected to the second sliding rod 34. The synchronous drive mechanism 37 can be a bidirectional cylinder, and the two output ends of the bidirectional cylinder are respectively connected to the first sliding rod 32 and the second sliding rod 34, or a conventional rack and pinion reverse equidistant transmission mechanism, and the two sides of the gear are respectively engaged with the upper rack or the lower rack, the first sliding rod 32 is fixedly connected to the upper rack, and the second sliding rod 34 is fixedly connected to the lower rack, and driving any one rack to move can drive the other rack to move in the opposite direction.

[0159] A plastic product is prepared by adopting the above-mentioned pull-down sealing structure shaping process method or is made by the above-mentioned secondary encapsulation mold, so it has good wall thickness consistency and high structural strength.

[0160] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A process for finalizing a pull-down sealing structure, characterized in that: The following steps are involved: S1, the extrusion mechanism (4) extrudes a rubber mold blank (5) having a hollow cavity between the first mold plate (1) and the second mold plate (2); S2, the first mold plate (1) and the second mold plate (2) are covered together to cut off the rubber blank (5) extruded by the extrusion mechanism (4); S3, a first sliding rod (32), a second sliding rod (34) and a blowing head (35) extend from below the first mold plate (1) into the hollow cavity of the rubber mold blank (5); S4, the first sliding rod (32) and the second sliding rod (34) move relative to each other to stretch the hollow cavity of the plastic mold blank (5); S4.1, the first sealing plate (61) and the second sealing plate (62) are brought closer to each other, enclosing the first sliding rod (32), the second sliding rod (34) and the blowing head (35) to seal the hollow cavity; S5, the blowing head (35) blows air into the hollow cavity, so that the plastic mold blank (5) expands and fits the inner walls of the first mold plate (1) and the second mold plate (2); S6, the cooling mechanism of the outer wall of the first mold plate (1) and the second mold plate (2) is operated to reduce the temperature and cool the first mold plate (1) and the second mold plate (2); S7, separating the first mold plate (1) and the second mold plate (2), retracting the first sealing plate (61), the second sealing plate (62), the first sliding rod (32), the second sliding rod (34) and the blowing head (35), and obtaining a molded plastic product.

2. The process for finalizing the pull-down sealing structure according to claim 1, characterized in that: The inner walls of the first mold plate (1) and the second mold plate (2) include a changing portion (12) and a smooth portion (21); In step S2, the extrusion mechanism (4) extrudes material until the thickness of the rubber blank (5) at the changing portion (12) is greater than the thickness of the rubber blank (5) at the smooth portion (21).

3. The process for finalizing the pull-down sealing structure according to claim 2, characterized in that: Also includes step S5.1 and step S6.2; Wherein, step S5.1: the first movable module (14) on the first mold plate (1) and the second movable module (24) on the second mold plate (2) move toward the changing portion (12) to squeeze the plastic mold blank (5) of the changing portion (12), so that the plastic mold blank (5) located at the changing portion (12) is in contact with the inner walls of the first mold plate (1) and the second mold plate (2); Wherein, step S6.1: the first active module (14) and the second active module (24) are reset.

4. The process for finalizing the pull-down sealing structure according to claim 1, characterized in that: Also includes steps S4.2 and S6.2, In step S4.2, the first cover plate driving component (162) drives the first cover plate (161) to rise and fall relative to the first mold plate (1), and the second cover plate driving component (262) drives the second cover plate (261) to rise and fall relative to the second mold plate (2), so that the first cover plate (161) and the second cover plate (261) extrude the rubber blank (5); Wherein, in step S6.2, the first cover plate (161) and the second cover plate (261) are reset.

5. The process for finalizing the pull-down sealing structure according to claim 1, characterized in that: The step S2 comprises: the lifting drive member drives the inner die nozzle (41) to rise and fall relative to the outer die nozzle (42), thereby adjusting the width of the discharge channel (44) between the outer wall of the inner die nozzle (41) and the inner wall of the outer die nozzle (42), so as to control the thickness of the extruded rubber blank (5).

6. Secondary overmolding mold, characterized by: It comprises a first mold plate (1) and a second mold plate (2); The first mold plate (1) and the second mold plate (2) enclose an injection molding cavity; A material extrusion mechanism (4) is provided on the top of the first mold plate (1) and the second mold plate (2); The bottom of the first mold plate (1) and the second mold plate (2) are provided with a base (31), a first sliding rod (32), a slide rail (33), a second sliding rod (34) and a blowing head (35); The air blowing head (35) is arranged directly below the extruding mechanism (4) and is fixedly connected to the base (31); the air blowing head (35) is arranged between the first sliding rod (32) and the second sliding rod (34); The slide rail (33) is arranged on the base (31), and the first sliding rod (32) and the second sliding rod (34) are slidably arranged on the slide rail (33).

7. The secondary overmolding mold according to claim 6, characterized in that: The extrusion mechanism (4) comprises an inner die nozzle (41), an outer die nozzle (42) and a lifting drive member; The inner die nozzle (41) is in the shape of a truncated cone, and has a bottom surface (411) and a top surface (412). The diameter of the bottom surface (411) is greater than the diameter of the top surface (412), and the bottom surface (411) is arranged toward the first die plate (1) and the second die plate (2). The inner wall of the inner cavity of the outer die nozzle (42) is geometrically matched with the outer wall of the inner die nozzle (41); A material discharge channel (44) is provided between the inner wall of the outer die nozzle (42) and the outer wall of the inner die nozzle (41); The output end of the lifting drive member is fixedly connected to the inner die nozzle (41), and the lifting drive member can drive the inner die nozzle (41) to move relative to the outer die nozzle (42).

8. The secondary overmolding mold according to claim 7, characterized in that: The inner cavity of the inner die nozzle (41) is a truncated cone-shaped cavity.

9. The secondary overmolding mold according to claim 6, characterized in that: It also includes a base lifting drive member, the output end of the base lifting drive member is fixedly connected to the base (31), and the blowing head (35) is arranged on the base (31); The base lifting drive member can drive the blowing head (35), the first sliding rod (32) and the second sliding rod (34) to move relative to the injection cavity.

10. A plastic product, characterized in that: The method is adopted to prepare the pull-down sealing structure according to any one of claims 1 to 5 or is made by the secondary encapsulation mold according to any one of claims 6 to 9.

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