CN203752426U - Thin Wall Injection Mold - Google Patents

Abstract

The utility model discloses a thin wall injection mold, including front mould subassembly, back mould subassembly, piece-rate system, cooling system and heating control module. The separation system is used for separating the cooling system from the mold core; the rear mould component comprises a rear mould core, a mould blank B plate, a rear mould insert and a cavity volume adjusting system, wherein the cavity volume adjusting system is arranged on the mould blank B plate and used for enabling the rear mould insert and the rear mould core to move relatively so as to adjust the cavity volume; the heating control module is used for heating the cavity and controlling the temperature of the cavity. The utility model provides a large tracts of land thin wall plastic part that thin wall injection mold preparation obtained has the advantage of fine and close, packing respond well, the surface does not have the weld mark, does not have the air line, has reached the effect that the spraying was exempted from to surperficial highlight.

Description

Thin Wall Injection Mold

technical field

The utility model relates to the field of injection molding, in particular to a thin-wall injection mold capable of manufacturing large-area thin-wall plastic parts.

Background technique

Existing mobile phones, notebooks, tablet computers and other products are showing a trend of thinning and thinning, and the thickness of related plastic structural parts is getting thinner and thinner. At present, the thickness of large-area plastic structural parts is generally above 0.7mm. Plastic structural parts are generally difficult to fill completely, resulting in lack of glue in the product, and there are adverse factors such as weld lines, surface air marks, and air traps on the surface, which cannot achieve a high-gloss surface effect.

Utility model content

The purpose of the utility model is to propose a thin-wall injection mold to solve the problems of poor filling effect, lack of glue and rough surface of the thin-wall plastic parts manufactured by the existing mold.

The utility model provides the following technical solutions:

A thin-walled injection mold, including a front mold assembly, a separation system, a cooling system, a heating control module and a rear mold assembly, the front mold assembly includes a front mold core, and the rear mold assembly includes a rear mold core; The cooling system includes a cooling block, and pipes are arranged in the cooling block for circulation of cooling liquid; the separation system is arranged at the bottom of the front mold core, and the front mold core and the cooling core are separated by the separation system. System separation; the rear mold assembly also includes a mold base B plate, a rear mold insert and a cavity capacity adjustment system, and the cavity capacity adjustment system is arranged on the mold base B plate for making the rear Relative movement occurs between the mold insert and the rear mold core to adjust the cavity capacity; the heating control module includes a temperature sensing system, a temperature control system and a heating system, and the temperature control system is connected to the temperature sensing system and the heating system respectively The heating system is distributed on the front mold core and/or the rear mold core for heating the cavity, and the temperature sensing system is in contact with the cavity for obtaining the temperature of the cavity and transmitting it to the The temperature control system is used to control the operation of the heating system. In this solution, the cooling system is separated from the front mold core before the mold is closed, and the mold cavity is heated through the heating control module, so that the temperature of the cavity can reach the melting point of the molding material before the mold is closed, so as to create a high-temperature molding Conditions, in order to obtain large-area thin-walled plastic parts with smooth surface, adjust the cavity volume through the cavity volume adjustment system, so that the volume of the cavity can be larger than the volume of the product, and there is still a cavity volume larger than the volume of the product after the mold is closed. In this way, it is possible to inject molten raw materials that are larger than the volume of the product, and then use the clamping pressure of the injection molding machine to squeeze the cavity to adjust the cavity capacity to be equal to the volume of the product; after extrusion, the rubber can be completely and evenly filled, The surface effect is good, the obtained plastic parts have high hardness, the surface is not easy to scratch and wear, and the internal stress of the product is also reduced through extrusion, so that the product is not easy to deform. In this way, dense, high-hardness large-area thin-walled products are obtained, and the filling effect is good, the surface is smooth, no weld marks, no air marks, and the effect of high gloss and no spraying is achieved.

Preferably, the front mold assembly also includes a mold base A board, a panel, a first heat insulation board and a second heat insulation board, the cooling system is connected to the panel, and the panel is used to place the front mold The assembly is locked to an injection molding machine, the front mold core is connected to the mold base A plate, the first heat insulation board is arranged between the panel and the mold base A plate, and the second insulation The hot plate is arranged on the panel for blocking the heat from the injection molding machine. The cooling system is connected to the panel, that is, the panel is cold, and the mold base A is connected to the front mold core, that is, the mold base A is also hot when the front mold core is heated, and the first heat insulation board is installed between the panel and the mold base A In between, on the basis of the separation of the cooling system and the front mold core, it plays a role of further heat insulation, ensuring that the heating system can not be affected by the cold source when heating the cavity, and can quickly heat up.

Preferably, the separation system includes a first spring, a first guide post and a first limit block, the first spring is located at the bottom of the front mold core, so as to eject the front mold core before the mold is closed. The front mold core is separated from the cooling system, the first guide post is installed on the mold base A plate for ejecting and guiding the front mold core, and the first limit block is used to limit The pop-up distance of the front mold core.

Preferably, the cavity capacity adjustment system includes a second spring, a second guide post and a second limit block, the second spring is located at the bottom of the rear mold core, so as to place the rear mold core before closing the mold. The spring-up causes relative movement between the rear mold core and the rear mold insert, increasing the cavity capacity, and the second guide post is installed on the mold base B plate for springing the rear mold core. The lifting guide, the second limit block is used to limit the bounce distance of the rear mold core.

Preferably, the temperature control system is arranged on the mold base A plate, has a heating control switch and a temperature control box, and the cavity temperature to be achieved or the heating time of the heating system are set through the temperature control box, and the heating The control switch is used to control the on-off of the heating system.

Preferably, the mold base A plate is provided with a mold clamping sensor pin, one end of the mold clamping sensor pin is in contact with the heating control switch, and the other end is in contact with the rear mold assembly when the mold is clamped; mold opening When the mold is closed, the clamping sensor needle pops up, so that the heating control switch is in the pop-up state, so that the heating system starts to heat; when the mold is closed, the mold clamping sensor pin is pressed so that the heating control switch is pressed down, The heating system stops heating.

Preferably, the heating system is an electric heating rod, and the electric heating rod is arranged in a part of the cavity having an appearance surface of the product.

Preferably, the rear mold assembly further includes a bottom plate, and square iron is provided on the bottom plate to support the mold base B plate.

Preferably, the rear mold assembly further includes an ejection system, the ejection system includes an ejection bottom plate, an ejection panel and a push rod, one end of the push rod is fixed on the ejection bottom plate, and the other end is connected to the The rear mold insert; the ejection panel is located on the ejection bottom plate, and the ejection panel is provided with a rear mold support column and an ejection limit block, and the rear mold support column is used to support the For the rear mold core, the ejection limit block is used to limit the distance from which the push rod is ejected from the rear mold insert.

To sum up, the thin-walled injection mold provided by the utility model has at least the following beneficial effects: injection-molded large-area thin-walled plastic parts have good filling effect, the product does not lack glue, and has high density and good hardness.

Description of drawings

Fig. 1 is a schematic structural view of the front mold assembly when the thin-walled injection mold of the utility model embodiment is in the mold opening state;

Fig. 2 is a schematic diagram of the structure of the rear mold assembly when the thin-walled injection mold of the embodiment of the present invention is in the mold opening state;

Fig. 3 is another schematic structural view of the front mold assembly of the thin-walled injection mold according to the embodiment of the present invention;

Fig. 4 is a schematic structural view of the front mold assembly in Fig. 1 when final mold closing;

Fig. 5 is a schematic structural view of the back mold assembly in Fig. 2 when final mold closing;

Fig. 6 is the process flow diagram of preparing thin-walled plastic parts using the thin-walled injection mold of the present embodiment;

Fig. 7 is a schematic structural view of the thin-walled injection mold of the embodiment of the present invention in the state of mold opening.

Explanation of reference signs:

11 front mold core, 12 mold base A board, 13 panel, 14 first heat insulation board, 15 second heat insulation board;

21 rear mold core, 22 mold base B plate, 23 rear mold insert, 24 rear mold support, 25 square iron, 26 base;

31 first spring, 32 first guide post, 33 first limit block;

40 cooling system;

51 Temperature sensing system, 52 Temperature control system, 53 Heating system, 54 Clamping sensor pin;

521 heating control switch;

61 second spring, 62 second guide post, 63 second limit block, 64 guide post pressing block;

71 push rod, 72 thimble panel, 73 thimble bottom plate;

81 nozzles, 82 positioning rings.

Detailed ways

The utility model will be further described below with reference to the accompanying drawings and in conjunction with preferred embodiments.

Concept definition:

The bottom of the front mold core: refers to the side opposite to the product forming contact surface of the front mold core, that is, the side away from the cavity.

The bottom of the rear mold core: refers to the side opposite to the product forming contact surface of the rear mold core, that is, the side away from the cavity.

The thin-walled injection mold provided in this embodiment is shown in Figure 7. The thin-walled injection mold includes a front mold assembly, a rear mold assembly, a separation system, a cooling system and a heating control module, which can be viewed in conjunction with Figures 1 to 5 , wherein the separation system, the cooling system and the heating control module are all arranged on the front mold assembly.

As shown in Figure 1: the front mold assembly includes a front mold core 11, a mold base A plate 12, a panel 13, a first heat insulation board 14 and a second heat insulation board 15; the separation system is located in the front The bottom of the mold core 11 is used to separate the front mold core 11 from the cooling system 40. In this embodiment, the separation system includes a first spring 31, a first guide post 32 and a first limit block 33; A spring 31 is located at the bottom of the front mold core 11, one end of which is in contact with the front mold core 11, and the other end is in contact with the mold base A plate 12; the first guide post 32 is installed on the mold base A plate 12 Above, the front mold core is provided with a guide hole compatible with the first guide post 32, one end of the first guide post 32 is pressed against the first heat shield 14, and the other end is installed with the first limit block 33. The first guide post 32 passes through the guide hole on the front mold core 11 to guide when the front mold core 11 moves. Preferably, the two ends of the bottom of the front mold core are respectively provided with a set of the aforementioned separation systems. When the mold is in the mold-opening state, under the action of the first spring 31, the front core 11 is ejected to leave the cooling system 40, and the maximum distance of ejection is limited by the first stopper 33; The cooling system 40 is fixed on the panel 13, so the panel 13 belongs to the cooling source, and the front mold core 11 is connected with the mold base A plate 12, so the mold base A plate also needs to be connected with the cooling system 40 (or cold source) isolation, because the mold base A plate 12 needs to be locked on the panel 13, so the first Heat shield 14, and because the panel 13 needs to be locked on the injection molding machine, and the injection molding machine is hot, the second panel 13 and the injection molding machine (not shown) are provided Insulation plate 15, like this, just can make mold before clamping mold, and cold source and heat source do not interfere with each other.

As shown in Fig. 1 and Fig. 3, wherein Fig. 3 is another schematic structural view for illustrating the position structure of the heating control module in the front mold assembly, the heating control module includes a temperature sensing system 51, a temperature control system 52 and heating system 53 . As shown in Figure 1, the temperature-sensing system 51 is arranged on the front mold core 11, which can sense the cavity temperature; the heating system 53 is arranged on the front mold core 11, and the position is preferably not close to the temperature-sensing system. 51 is too close to avoid the temperature sensing system 51 being affected by the heating system 53; as shown in Figure 3, the temperature control system 52 is located on the mold base A plate 12, and has a heating control switch 521 and a temperature control box ( not shown in the figure), the temperature control box is used to regulate the heating temperature and/or heating time, and the heating control switch 521 is used to control the on-off of the heating system 53 .

As shown in Figures 2 and 5, the rear mold assembly includes a rear mold core 21, a mold base B plate 22, a rear mold insert 23, a rear mold support column 24, a square iron 25, a base 26 and a cavity capacity adjustment system , the rear mold core 21 is connected to the mold base B plate 22, one end of the rear mold support column 24 abuts the mold base B plate, and the other end abuts the base 26, and the square iron 25 is used for Support the mold base B plate 22; the cavity capacity adjustment system is used to bounce the rear mold core before closing the mold to make the relative movement between the rear mold core and the rear mold insert to increase the cavity capacity , the cavity capacity adjustment system includes a second spring 61, a second guide post 62 and a second limit block 63; The core 21 abuts, and the other end abuts on the mold base B plate 22; the second guide post 62 is installed on the mold base B plate, and one end is fixed on the mold base by a guide post pressing block 64 The bottom of the B plate and the other end are provided with the second limit block 63; the rear mold core 21 is provided with a guide hole that is compatible with the second guide post, and the rear mold core 21 passes through the guide hole through the second guide hole. on the second guide post 62 , so that the motion is guided by the second guide post 62 , and the position is limited by the second limit block 63 .

Looking at Fig. 2 again, the ejection system of the mold is also shown in Fig. 2. The ejection system includes a push rod 71, a thimble panel 72 and a thimble bottom plate 73. It should be noted that after the molding is cooled, the mold is opened, due to the When the push rod 71 ejects the finished product, it ejects the finished product by lifting the rear mold insert 23, so the rear mold insert 23 can also be counted as a part of the ejection system. The rear mold insert 23 is fastened with the push rod 71, and the push rod 71 passes through the hole of the mold base B plate to play the role of ejection guide at the same time, and is assembled between the thimble panel 72 and the thimble bottom plate 73, and the thimble The panel 72 and the thimble bottom plate 73 are locked by screws.

Fig. 3 is another schematic structural view of the front mold assembly, as shown in Fig. 3, the nozzle 81 of the gating system of the mold passes through the front mold core 11 and leads to the cavity, and the nozzle 81 is fixed by a positioning ring 82 On the panel 13, and through the positioning of the positioning ring 82, it is ensured that the nozzle 81 is aligned with the nozzle of the injection molding machine for precise injection.

This embodiment also provides a method for preparing thin-walled plastic parts. The process flow chart of the method is shown in Figure 6. The preparation method mainly includes the following four steps S1-S4:

S1. Before closing the mold: separate the cooling system from the front mold core and the rear mold core; make the rear mold core and the rear mold insert move relative to each other, and increase the cavity capacity to be larger than the volume of the plastic part to be prepared; The part on the mold core that has the appearance surface of the plastic part is heated until the temperature reaches above the melting point of the plastic.

S2. Clamping the mold for the first time: incompletely clamp the front mold core and the rear mold core until the mold cavity is closed, and keep the volume of the mold cavity still greater than the volume of the plastic part;

S3. Injection: inject molten plastic into the sealed cavity formed in step S2, and the injection volume is greater than the volume of the plastic part;

S4. Final mold closing: use the mold closing pressure of the injection molding machine to squeeze the mold cavity, for example, use the mold closing pressure of a 100-ton injection molding machine to squeeze, so that the front mold core and the rear mold core are molded together until the cavity capacity is equal to the plastic part Volume; the cooling system is in contact with the front mold core and the rear mold core.

Based on the thin-wall injection mold provided in this example, the case of preparing a plastic part with the above preparation method is as follows. The plastic part only has an appearance surface on the cavity of the front mold core, and the rear mold core has no appearance surface, so heating and Cooling is mainly for the front mold core:

In conjunction with Figure 1 and Figure 6, before the mold is closed: the first spring 31 of the separation system is in a natural state, and the front mold core 11 is ejected by the first spring 31 for a certain distance. It can be seen from Figure 1 that the front mold core There is a distance between 11 and the cooling system 40, so the front mold core 11 can be separated from the cooling system 40. For the rear mold assembly, the second spring 61 of the cavity capacity adjustment system is in a natural state, and the rear mold core 21 is ejected a certain distance by the second spring 61. As can be seen from FIG. 2, the rear mold core 21 is larger than the rear mold insert 23 Higher than the distance H1, the cavity capacity corresponding to the height difference H1 is greater than the volume of the plastic part to be prepared. Assuming that the volume of the plastic part is V, the cavity capacity corresponding to the normal situation (that is, the ordinary mold) is also V. In this In the utility model mold, the cavity capacity V1 corresponding to the height difference H1 in Figure 2 can be 1.5 to 2 times the volume V of the plastic part, but it is not limited to this, as long as the cavity capacity is greater than the volume of the plastic part in the mold opening state . The front mold core 11 is heated by the heating system 53 provided on the front mold core 11 until the temperature of the front mold core 11 (or the cavity on the front mold core) reaches above the melting point of the raw material to be injection molded, in order to save energy, as long as it is heated to the melting point and maintained at that temperature. Set the temperature or heating time to be achieved through the temperature control box, and monitor the heating temperature in real time by setting a temperature sensing system 51 (which can be a temperature sensing rod or a temperature sensor, etc.) in the cavity of the front mold core 11. As shown in Figure 3, the heating control module also includes a mold clamping sensor pin 54, which is arranged on the mold base A plate, and the mold clamping sensor pin 54 is extruded by the rear mold assembly when the mold is closed. Squeeze the heating control switch 521, so that the heating control switch 521 cuts off the power supply of the heating system, so that the heating system stops heating. Here, it can be designed to stop heating when the mold is closed for the first time, or it can be designed to close the mold at the end When the heating is stopped. When the mold is opened, the mold closing sensor pin 54 is no longer under pressure and pops up, so the heating control switch 521 also pops up, so that the heating system 53 starts to heat. It should be noted that the heating system 53 stops the heating signal in addition to the above-mentioned stop heating when the mold is closed, there is another signal to stop the heating: before the mold is closed, if the temperature sensing system 51 detects that the temperature reaches the set heating temperature, or reach the set heating time, the heating system will stop heating.

After the above preparations are in place, the initial mold clamping can be performed. Unlike ordinary injection molding, the initial mold clamping does not directly close the mold until the cavity capacity of the mold is equal to the volume of the plastic part. In this embodiment, the volume of the cavity until the mold is closed for the first time is 1.1 to 1.2 times the volume V of the plastic part. After the initial mold closing, the molten plastic can be injected through the gating system. As shown in Figure 3, the molten plastic that is 1.05 to 1.15 times the volume V of the plastic part is injected into the cavity through the nozzle 81. In short, the amount of injection must be more than that of the plastic part. Volume V. After the injection is completed, use the mold clamping pressure of the injection molding machine to squeeze the cavity for final mold clamping until the volume of the cavity is equal to the volume V of the plastic part. At this time, the front mold assembly is in the state shown in Figure 1, and the rear mold Components are shown in Figure 5. During the mold closing process, the front mold core is squeezed by the rear mold core and gradually approaches the cooling system, but because the injection and extrusion time is very short, after contacting the cooling system, the front mold core is also heated beforehand, so it cools down The system will not affect the molten plastic and still maintain good fluidity. In this state, use a larger injection molding machine to squeeze the cavity. The pressure of the extrusion cavity of the injection molding machine is selected according to different products. The tonnage of the pressure can be adjusted. Ten tons, hundreds of tons, etc. should not be limited. It is only necessary to clarify that the pressure is not only a clamping pressure, but more importantly, the pressure is used to squeeze the cavity to obtain dense plastic parts with good filling effect. . The plastic parts obtained according to the method have a good filling effect, and at the same time, there are no welding marks and air marks on the surface, and a high-gloss, spray-free large-area thin-walled plastic part with a good surface effect is obtained.

It should be noted that the cooling system and the heating system, the front mold assembly and the rear mold assembly can be set, and it is not limited to the case where only the cavity of the front mold core has an appearance surface in the aforementioned case. In fact, the utility model provides For thin-walled injection molds, at least the parts with product appearance on the front mold core and the rear mold core should be equipped with a cooling system and a heating system, because the cavity in contact with the product appearance surface is heated above the melting temperature of the molding material before injection and extrusion. Press molding, the appearance surface of the obtained product is smooth without weld marks. For the cooling system and heating system, it is best to be able to rapidly cool and heat rapidly. For example, to prepare a plastic part with a raw material of PC+20GF and a thickness of 0.4mm, the heating system should be able to raise the heated part by 7°C per second. For example, the cooling system can cool at a rate of 12°C/s; another example is to prepare a plastic part made of PMMA with a thickness of 0.6mm, which is heated at 6°C/s and cooled at 11°C/s. Of course, the foregoing is merely an enumeration to show that cooling and heating need to be as fast as possible. The cooling block of the cooling system is made of metals with fast heat conduction and low cost, such as copper. There are pipes in the cooling block. The cooling liquid is provided by the chiller and circulates continuously in the pipes to ensure that the cooling temperature remains constant. The heating system can use electric heating rods. At the same time, the speed of temperature rise and cooling is also related to the number of heating rods in the heating system, and the cooling is related to the size of the cooling block and the temperature of the cooling water.

In short, the utility model is used to provide a thin-walled injection mold. Through the preparation method of the thin-walled plastic parts of the utility model, the high-temperature molding conditions for the appearance surface of the product are created by cavity preheating, and then the cavity capacity adjustment system is used to increase the injection ratio to normal conditions. More raw materials, two times of mold clamping, by using the clamping pressure normally used to close the mold and seal the glue to compress the cavity (or extrude the molten plastic) to obtain dense, high surface hardness, Plastic parts with good filling effect, at the same time, the obtained plastic parts have no weld marks and air marks on the surface, and have good surface effects, reaching the level of high gloss without spraying; at the same time, the obtained plastic parts have reduced internal stress and are not easy to deform.

The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be assumed that the specific implementation of the utility model is only limited to these descriptions. For those skilled in the technical field to which the utility model belongs, on the premise of not departing from the concept of the utility model, some equivalent substitutions or obvious modifications can also be made, and the performance or use is the same, which should be regarded as belonging to the utility model. protected range.

Claims (9)

1. a thin-walled plastic injection mold, comprises front membrane module and rear membrane module, and described front membrane module comprises front cavity, and described rear membrane module comprises rear cavity, it is characterized in that: also comprise piece-rate system, cooling system and heating control module;

Described cooling system comprises cooling block, is provided with pipeline and circulates for liquid circulation in described cooling block;

Described piece-rate system is located at described front cavity bottom, by described piece-rate system, makes described front cavity separated with cooling system;

Described rear membrane module also comprises mold base B plate, rear mold mold insert and die cavity capacity adjustment System, and described die cavity capacity adjustment System is located on described mold base B plate, for making, between described rear mold mold insert and described rear cavity, relative motion occurs to adjust die cavity capacity;

Described heating control module comprises temperature-sensitive system, temperature control system and heating system, and described temperature control system is connected with heating system with temperature-sensitive system respectively; Described heating system is distributed in described front cavity and/or described rear cavity, for heating to die cavity, described temperature-sensitive system contacts with die cavity, and for obtaining the temperature of described die cavity and transferring to described temperature control system, described temperature control system is for controlling the work of described heating system.

2. thin-walled plastic injection mold as claimed in claim 1, it is characterized in that: described front membrane module also comprises mold base A plate, panel, the first thermal insulation board and the second thermal insulation board, described cooling system is connected with described panel, described panel is for securing to an injection machine by described front membrane module, described front cavity is connected with described mold base A plate, described the first thermal insulation board is located between described panel and described mold base A plate, and described the second thermal insulation board is located on described panel, for intercepting the heat from injection machine.

3. thin-walled plastic injection mold as claimed in claim 2, it is characterized in that: described piece-rate system comprises the first spring, the first guide pillar and the first limited block, described the first spring is positioned at described front cavity bottom, described front cavity is ejected described front cavity and described cooling system is separated before mould matched moulds, described the first guide pillar is arranged on described mold base A plate, for described front cavity is ejected to guiding, described the first limited block is for limiting the ejection distance of described front cavity.

4. thin-walled plastic injection mold as claimed in claim 1, it is characterized in that: described die cavity capacity adjustment System comprises the second spring, the second guide pillar and the second limited block, described the second spring is positioned at described rear cavity bottom, described rear cavity is upspring before matched moulds, make described rear cavity and described rear mold mold insert generation relative motion, increase die cavity capacity, described the second guide pillar is fixed on described mold base B plate, for guiding that described rear cavity is upspring, described the second limited block is for limiting the distance of upspringing of described rear cavity.

5. thin-walled plastic injection mold as claimed in claim 2, it is characterized in that: described temperature control system is located on described mold base A plate, there is heating gauge tap and temperature control box, the die cavity temperature of wanting to reach by described temperature control box setting or the heat time of heating system, described heating gauge tap is for controlling the break-make of described heating system.

6. thin-walled plastic injection mold as claimed in claim 5, is characterized in that: described mold base A plate is provided with matched moulds inductive needle, and described matched moulds inductive needle one end contacts with described heating gauge tap, and the other end contacts with described rear membrane module when mould matched moulds; Described in during die sinking, matched moulds inductive needle is upspring, and makes described heating gauge tap in the state of upspringing, and makes described heating system start heating; Described in during matched moulds, matched moulds inductive needle is pressed described heating gauge tap is depressed, and described heating system stops heating.

7. thin-walled plastic injection mold as claimed in claim 6, is characterized in that: described heating system is electrically heated rod, and described electrically heated rod is arranged in the position in described die cavity with Surface Appearance.

8. thin-walled plastic injection mold as claimed in claim 1, is characterized in that: described rear membrane module also comprises base plate, and described base plate is provided with square iron to support described mold base B plate.

9. thin-walled plastic injection mold as claimed in claim 8, it is characterized in that: described rear membrane module also comprises ejection system, described ejection system comprises and ejects base plate, ejects panel and push rod, and described push rod one end ejects on base plate described in being fixed on, and the other end connects described rear mold mold insert; The described panel that ejects ejects on base plate described in being positioned at, the described panel that ejects is provided with rear mold support column and ejecting limit block, described rear mold support column is in order to support described rear cavity, and described ejecting limit block is for limiting the distance that described push rod ejects described rear mold mold insert.