Blown film die head

Abstract

The present invention discloses a film blowing die head, comprising a mold shell, a spiral body, a mold ring, an adapter and an air pipe joint, wherein the interior of the spiral body is provided with an air passage running through the top thereof along its axial direction, the interior of the spiral body is provided with a plurality of feed channels along its radial direction outward, the adapter is installed at the bottom of the spiral body and communicated with the feed port of the feed channel, the mold shell is fixedly sleeved on the outside of the spiral body and forms a flow channel with a lower end seal between the spiral body, the spiral body is provided with an annular block above the discharge port of the feed channel, the distance between the annular block and the mold shell at the discharge port corresponding to the annular block is greater than the distance between the two sides of the annular block and the mold shell, the mold ring is fixedly sleeved on the top of the spiral body and located at the top of the mold shell, a discharge channel is formed between the mold ring and the spiral body, and the air pipe joint is fixed on the spiral body and communicated with the air passage. The present invention effectively ensures uniform thickness of the film at all places, and improves the cost quality of the film.

Description

Technical Field

[0001] The invention relates to a film blowing die head and belongs to the technical field of film blowing parts. Background Art

[0002] The blown film die is an important part of the film production equipment and directly affects the quality of the produced film. Most of the existing blown film die heads are composed of a mold shell, a spiral body and a mold ring. The spiral body is placed in the mold shell, and the mold ring is sleeved on the spiral body. A spiral groove is opened on the side of the spiral body along its axial direction. The bottom of the spiral body is provided with a feed channel connected to the spiral groove. The melt enters the spiral groove from the feed channel and rises along the spiral groove to the discharge channel between the spiral body and the mold ring and is blown by the air channel to form a film. Although this blown film die head can meet the use needs to a certain extent, its disadvantage is that when the outlet of the spiral groove enters the discharge channel, the melt has different flow rates at different places in the discharge channel, making the melt unevenly distributed. This causes the film thickness to be uneven after the melt is blown into a film, affecting the quality of the film. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides a film blowing die head.

[0004] The present invention can be implemented by adopting the following technical solutions:

[0005] A film blowing die head comprises a mold shell, a spiral body, a mold ring, an adapter and an air pipe joint. The interior of the spiral body is provided with an air passage running through the top thereof along its axial direction, and the interior of the spiral body is provided with a plurality of feed channels along its radial direction outward. The adapter is installed at the bottom of the spiral body and is connected with the feed port of the feed channel. The mold shell is fixedly sleeved on the outside of the spiral body and forms a flow channel with a lower end seal between the spiral body. The spiral body is provided with an annular block above the discharge port of the feed channel. The distance between the annular block and the mold shell at the discharge port is greater than the distance between the two sides of the annular block and the mold shell. The mold ring is fixedly sleeved on the top of the spiral body and is located at the top of the mold shell. A discharge channel is formed between the mold ring and the spiral body, and the air pipe joint is fixed on the spiral body and is connected with the air passage.

[0006] Preferably, the distance between the annular block and the mold shell gradually decreases from a position corresponding to the discharge port to both sides.

[0007] Preferably, a middle portion of the spiral forms an annular groove inwardly above the annular block.

[0008] Preferably, the groove and the top end of the spiral body and the annular block form an arc transition.

[0009] Preferably, a base is provided at the bottom of the spiral body, the adapter is mounted on the base, the upper end of the adapter passes through the base and extends out of the spiral body, and the bottom of the mold shell is fixed on the base.

[0010] Preferably, the plurality of feed channels are distributed circumferentially on the spiral body.

[0011] Preferably, there is an arc transition between the annular block and the bottom end of the spiral body.

[0012] Preferably, the annular block and the spiral body are integrally formed.

[0013] Preferably, a first heater is provided on the outer side of the mold ring.

[0014] Preferably, a second heater is provided on the outer side of the mold shell.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: an annular block is provided above the outlet of the feed channel on the spiral body in the present invention, and the distance between the annular block and the mold shell corresponding to the outlet is greater than the distance between the two sides of the annular block and the mold shell. After the melt comes out of the outlet of the feed channel, it diffuses to four sides and moves upward along the flow channel. Since the melt flow rate at the outlet is the largest and gradually decreases to both sides, the distance between the annular block and the mold shell gradually decreases, so that the melt flow rate in the flow channel remains uniform and moves upward into the discharge channel, and then is blown into a thin film through the airway, effectively ensuring that the thickness of the film is uniform everywhere, and improving the cost quality of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the film blowing die head of the present invention;

[0017] Figure 2 is a structural exploded view of the film blowing die head of the present invention;

[0018] Figure 3 It is a schematic diagram of the structure of the spirochete of the present invention;

[0019] Figure 4 is a cross-sectional view of the spiral body and the mold shell of the present invention;

[0020] Among them, 1-mold shell, 2-spiral, 3-mold ring, 4-adapter, 5-air pipe joint, 6-base, 7-first heater, 8-second heater, 11-flow channel, 21-air channel, 22-feed channel, 23-annular block, 24-groove, 31-discharge channel. DETAILED DESCRIPTION

[0021] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0022] Example 1

[0023] like Figures 1 to 4 As shown, the film blowing die head of this embodiment includes a mold shell 1, a spiral body 2, a mold ring 3, an adapter 4 and an air pipe joint 5. The interior of the spiral body 2 is provided with an air channel 21 running through its top along its axial direction, and the interior of the spiral body 2 is provided with a plurality of feed channels 22 radially outwardly, the adapter 4 is installed at the bottom of the spiral body 2 and is connected to the feed port of the feed channel 22, the mold shell 1 is fixedly sleeved on the outside of the spiral body 2 and forms a flow channel 11 with a lower end seal between the spiral body 2, the spiral body 2 is provided with an annular block 23 above the discharge port of the feed channel 22, the distance between the annular block 23 and the mold shell 1 corresponding to the discharge port is greater than the distance between the two sides of the annular block 23 and the mold shell 1, the mold ring 3 is fixedly sleeved on the top of the spiral body 2 and is located at the top of the mold shell 1, a discharge channel 31 is formed between the mold ring 3 and the spiral body 2, and the air pipe joint 5 is fixed on the spiral body 2 and is connected to the air channel 21. The melt enters the bottom of the spiral body 2 from the adapter 4 and flows out through the feed channel 22 to diffuse and move up along the flow channel 11 between the mold shell 1 and the spiral body 2. Since the flow rate at the outlet of the feed channel 22 is large and the flow rate is fast and gradually decreases on both sides, the distance between the annular block 23 and the mold shell 1 gradually decreases, so that the melt flow rate in the flow channel remains uniform and moves up into the discharge channel 31, and then blown into a film through the air channel 21. The film blowing die head of this embodiment effectively ensures uniform thickness of the film at all locations, and improves the cost quality of the film.

[0024] In this embodiment, the distance between the annular block 23 and the mold shell 1 gradually decreases from the corresponding position of the discharge port to both sides, so that the melt flow rate at each location remains the same. The middle part of the spiral 2 forms an annular groove 24 inwardly above the annular block 23, and the groove 24 is used to buffer the melt to ensure that the melt flow rate at each location entering the discharge channel 31 is the same. The groove 24 and the top of the spiral 2 and the annular block 23 are in an arc transition to facilitate the flow of the melt.

[0025] In this embodiment, a base 6 is provided at the bottom of the spiral 2, and the adapter 4 is installed on the base 6, and its upper end passes through the base 6 and extends out of the spiral 2. The bottom of the mold shell 1 is fixed on the base 6, and the base 6, the spiral 2 and the mold shell 1 form a bottom seal, which is convenient for the melt to move upward along the flow channel 11. The multiple feed channels 22 are distributed in a circle on the spiral 2, which is convenient for the melt to flow out evenly from the feed channels 22. There is an arc transition between the annular block 23 and the bottom end of the spiral 2, which is convenient for the melt to flow. The annular block 23 is integrally formed with the spiral 2 to ensure the stability of the overall structure. A first heater 7 is provided on the outer side of the mold ring 3, and a second heater 8 is provided on the outer side of the mold shell to heat the melt and maintain its fluidity.

[0026] The present invention is described above in conjunction with preferred embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations based on the essence of the present invention.

Claims

1. A film blowing die head, characterized in that: It includes a mold shell, a spiral body, a mold ring, an adapter and an air pipe joint. The interior of the spiral body is provided with an air passage running through its top along its axial direction, and the interior of the spiral body is provided with a plurality of feed channels along its radial outward direction. The adapter is installed at the bottom of the spiral body and is connected with the feed port of the feed channel. The mold shell is fixedly sleeved on the outside of the spiral body and forms a flow channel with a lower end seal between the spiral body. The spiral body is provided with an annular block above the discharge port of the feed channel. The distance between the annular block and the mold shell corresponding to the discharge port is greater than the distance between the two sides of the annular block and the mold shell. The mold ring is fixedly sleeved on the top of the spiral body and is located at the top of the mold shell. A discharge channel is formed between the mold ring and the spiral body, and the air pipe joint is fixed on the spiral body and is connected with the air passage.

2. The film blowing die head according to claim 1, characterized in that: The distance between the annular block and the mold shell gradually decreases from the corresponding position of the discharge port to both sides.

3. The film blowing die head according to claim 1, characterized in that: The middle part of the spiral body forms an annular groove inwardly above the annular block.

4. The film blowing die head according to claim 3, characterized in that: The groove, the top end of the spiral body and the annular block are transitioned in an arc.

5. The film blowing die head according to any one of claims 1 to 4, characterized in that: A base is provided at the bottom of the spiral body, the adapter is installed on the base, the upper end of the adapter passes through the base and extends out of the spiral body, and the bottom of the mold shell is fixed on the base.

6. The film blowing die according to any one of claims 1 to 4, characterized in that: The plurality of feed channels are distributed circumferentially on the spiral body.

7. The film blowing die according to any one of claims 1 to 4, characterized in that: The annular block and the bottom end of the spiral body form an arc transition.

8. The film blowing die according to any one of claims 1 to 4, characterized in that: The annular block and the spiral body are integrally formed.

9. The film blowing die according to any one of claims 1 to 4, characterized in that: A first heater is arranged on the outer side of the mold ring.

10. The film blowing die head according to any one of claims 1 to 4, characterized in that: A second heater is arranged on the outer side of the mold shell.

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