BMC forming without runner structure

Abstract

The utility model relates to the production field of BMC molding material, concretely relates to a BMC forming runnerless structure. A kind of BMC forming runnerless structure of the utility model, including the valve needle plate of setting in turn, runner plate, first die cavity fixed plate and second die cavity fixed plate, fixedly provided with runner on the runner plate, the valve needle is equipped on the valve needle plate, the valve needle is in-depth runner, the first die cavity fixed plate and the second die cavity fixed plate are equipped with water jacket, the lower part of second die cavity fixed plate is equipped with cavity, and there is gap between cavity and water jacket.

Description

Technical Field

[0001] This utility model relates to the field of BMC molding compound production, specifically to a BMC molding without runner structure. Background Technology

[0002] In the existing BMC molding process, the material enters the cavity through a cutting valve pin and then is molded. However, in the existing technology, there is an excess stalk (an extra cylindrical protrusion) on the top of the molded plastic, which needs to be cut and polished, increasing the processing steps. Summary of the Invention

[0003] This invention aims to provide a runnerless structure for BMC molding, the specific solution of which is as follows: A BMC molding runnerless structure includes a valve cutting pin plate, a runner plate, a first mold cavity fixing plate, and a second mold cavity fixing plate arranged sequentially. A runner is fixedly provided on the runner plate, and a valve cutting pin is provided on the valve cutting pin plate, which extends into the runner. A water jacket is provided in the first mold cavity fixing plate and the second mold cavity fixing plate. A cavity is provided at the lower part of the second mold cavity fixing plate, and a gap exists between the cavity and the water jacket.

[0004] There are two valve needles and flow channels.

[0005] The water jacket includes a first water jacket and a second water jacket, with a sealing ring between the first water jacket and the second water jacket. This design facilitates the installation of the sealing ring.

[0006] Two sealing rings are provided, one at the top and one at the bottom of the first and second water jackets, respectively, to ensure a good seal.

[0007] The gap is 2-3mm. This size ensures that no excess material stalk is produced.

[0008] The working principle of this invention is as follows: BMC material is injected into the runner and then into the mold cavity through an injection molding machine. The runner is fixed inside the runner plate. Within the space between the first mold cavity fixing plate and the second mold cavity fixing plate, the runner is always surrounded by a water jacket, which cools the internal material and prevents it from being affected by mold heating. After injection, the equipment drives the valve cutting pin plate to move the valve cutting pin downward to the limit position. At this time, the valve cutting pin just enters the conical surface of the runner opening, sealing the runner and preventing material from entering the mold cavity while also maintaining pressure. At this time, the part below the gap between the water jacket and the mold cavity, up to the material inside the mold cavity, begins to solidify. When demolding is completed, the material at the injection port in the runner breaks at the gap. Above the gap, due to the cooling effect of the water jacket, the material is in an unsolidified state and can be directly injected into the mold cavity for use in the next molding cycle without the need to deal with excess material stalks. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a channelless BMC molding structure according to the present invention. Figure 2 for Figure 1 Cross-section Figure 1 ; Figure 3 for Figure 1 Cross-section Figure 2 ; Figure 4 This is a partial structural diagram of a BMC molding runnerless structure according to this utility model. Figure 1 ; Figure 5 This is a partial structural diagram of a BMC molding runnerless structure according to this utility model. Figure 2 ; Figure 6 This is a partial structural diagram of a BMC molding runnerless structure according to this utility model. Figure 3 ; The following are the labels: 1. Cutting valve needle plate; 2. Flow channel plate; 3. First mold cavity fixing plate; 4. Second mold cavity fixing plate; 5. Water jacket; 51. First water jacket; 52. Second water jacket; 6. Gap; 7. Cavity; 8. Sealing ring; 10. Flow channel; 11. Cutting valve needle. Detailed Implementation

[0010] The following is combined with Figure 1-6 Further explanation: A BMC molding runnerless structure includes a valve cutting pin plate 1, a runner plate 2, a first mold cavity fixing plate 3, and a second mold cavity fixing plate 4 arranged sequentially. A runner 10 is fixedly provided on the runner plate 2. A valve cutting pin 11 is provided on the valve cutting pin plate 1, and the valve cutting pin 11 extends into the runner 10. A water jacket 5 is provided in the first mold cavity fixing plate 3 and the second mold cavity fixing plate 4. A cavity 7 is provided at the lower part of the second mold cavity fixing plate 4, and there is a gap between the cavity 7 and the water jacket 5.

[0011] There are two valve needles 11 and flow channels 10.

[0012] The water jacket 5 includes a first water jacket 51 and a second water jacket 52, with a sealing ring 8 provided between the first water jacket 51 and the second water jacket 52. This design facilitates the installation of the sealing ring 8.

[0013] There are two sealing rings 8, which are respectively located at the upper and lower parts of the first water jacket 51 and the second water jacket 52. This ensures a good sealing effect.

[0014] The gap 6 is 2-3mm. This size ensures that no excess material stalk is produced.

[0015] The working principle of this utility model is as follows: BMC material is injected into the runner 10 through an injection molding machine and then into the cavity 7. The runner 10 is fixed inside the runner plate 2. Within the space of the first mold cavity fixing plate 3 and the second mold cavity fixing plate 4, the outer periphery of the runner 10 is always covered by a water jacket 5, which cools the internal material and is unaffected by mold heating. After injection, the equipment drives the valve cutting pin plate 1 to move the valve cutting pin 11 downward to the limit position. At this time, the valve cutting pin 11 just enters the conical surface of the runner 10 opening, sealing the runner and preventing material from entering the cavity 7, while also maintaining pressure. At this time, the part below the gap 6 between the water jacket 5 and the cavity 7 until the material in the cavity 7 begins to solidify. When demolding is completed, the material at the injection port in the runner 10 breaks at the gap 6. Above the gap 6, due to the cooling effect of the water jacket 5, the material is in an unsolidified state and can be directly injected into the cavity 7 for use in the next molding cycle without the need to deal with excess material stalks.

[0016] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A flow channel-free structure for BMC molding, characterized in that: The device includes a valve cutting needle plate, a flow channel plate, a first mold cavity fixing plate, and a second mold cavity fixing plate arranged in sequence. A flow channel is fixedly provided on the flow channel plate. A valve cutting needle is provided on the valve cutting needle plate, and the valve cutting needle extends into the flow channel. A water jacket is provided in the first mold cavity fixing plate and the second mold cavity fixing plate. A cavity is provided at the lower part of the second mold cavity fixing plate. There is a gap between the cavity and the water jacket.

2. The BMC molding channelless structure as described in claim 1, characterized in that: There are two valve needles and flow channels.

3. The BMC molding channelless structure as described in claim 1, characterized in that: The water jacket includes a first water jacket and a second water jacket, and a sealing ring is provided between the first water jacket and the second water jacket.

4. The BMC molding channelless structure as described in claim 3, characterized in that: There are two sealing rings, which are respectively located at the upper and lower parts of the first water jacket and the second water jacket.

5. The BMC molding channelless structure as described in claim 1, characterized in that: The gap is 2-3mm.

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